Arlon DiClad 880 is a woven PTFE/fiberglass laminate with Dk 2.17–2.20 and Df 0.0009 at 10 GHz — the lowest loss in the DiClad series. Complete engineer’s guide covering DiClad 880 specs, datasheet, thickness options, fabrication guidelines, and applications in military radar, missile guidance, and phased array PCBs.

There’s a certain category of microwave circuit where every fraction of a dB matters and where signal propagation speed is not just a datasheet talking point but a genuine system-level constraint. Missile guidance, military radar feed networks, low noise amplifier front ends, high-speed digital radio antennas — these are the applications where material selection is not a procurement afterthought but a core engineering decision. Arlon DiClad 880 was built for exactly that category.

With a dielectric constant of 2.17 or 2.20 and a dissipation factor of 0.0009 at 10 GHz, DiClad 880 delivers the lowest Dk and lowest loss available in the woven fiberglass-reinforced PTFE laminate family. If you’re designing circuits that need the fastest signal propagation and the smallest insertion loss penalty from the substrate, DiClad 880 is where you start.

This guide covers the complete picture: material construction, key specifications, available configurations, application breakdown, fabrication requirements, comparison with competing laminates, and the practical engineering judgment calls you need to make when DiClad 880 is on the table.

What Is Arlon DiClad 880?

Arlon DiClad 880 is a woven fiberglass/PTFE composite laminate that uses a low fiberglass/PTFE ratio to deliver the lowest dielectric constant and dissipation factor in the DiClad series. The “880” designation places it at the high-performance, low-Dk end of Arlon’s DiClad product family, which spans dielectric constants from 2.17 up to 2.65 depending on fiberglass loading.

The material achieves its ultra-low Dk through a deliberate compositional strategy: by minimizing the amount of woven fiberglass reinforcement and maximizing the PTFE fraction of the composite, Arlon pushes the effective dielectric constant of the composite down toward the intrinsic Dk of PTFE itself (approximately 2.1). The tradeoff is mechanical — lower fiberglass content means less rigidity and dimensional stability compared to more heavily reinforced PTFE laminates. DiClad 880 is explicitly engineered to prioritize electrical performance over mechanical convenience, which is exactly the right tradeoff for its target applications.

The coated fiberglass plies in DiClad materials are aligned in the same direction — this is the unidirectional construction that distinguishes DiClad from the cross-plied CuClad family. For applications where the primary requirement is the lowest possible Dk and loss rather than in-plane electrical isotropy, that unidirectional construction delivers the electrical performance targets at lower cost.

DiClad 880 Key Electrical Properties and Datasheet Specifications

Core Electrical Properties

Property	Value	Test Condition
Dielectric Constant (Dk)	2.17 or 2.20	10 GHz
Dissipation Factor (Df)	0.0009	10 GHz
Dk Stability vs. Frequency	Highly uniform across frequency	RF to microwave
Electrical Property Uniformity	Excellent across panel	Consistency of PTFE coating process

The Df of 0.0009 at 10 GHz is not just a low number in an abstract sense — it represents one of the lowest dissipation factors achievable in a woven fiberglass-reinforced laminate. For reference, laminates based on PTFE and reinforced with woven glass can be manufactured with low Dk (2.17) and loss as low as 0.0009 at 10 GHz. Standard FR-4 runs Df values of 0.020 or higher at high frequency — DiClad 880’s Df is more than 20 times lower.

Physical and Mechanical Properties

Property	Description
Reinforcement	Unidirectional woven fiberglass
Matrix	PTFE (polytetrafluoroethylene)
Fiberglass/PTFE ratio	Low (maximizes PTFE fraction)
Dimensional stability	Excellent vs. non-woven PTFE laminates
Dk uniformity	Better than non-woven PTFE laminates
Water absorption	Very low (PTFE-based)
Chemical resistance	Excellent
Copper cladding	Standard and heavy weights available

Available Thicknesses and Dk Options

From the Arlon Microwave & RF Materials Guide, DiClad 880 is available in the following configurations:

Thickness (inches)	Thickness (mm)	Available Dk Options
0.005″	0.127	2.17, 2.20
0.010″	0.254	2.17, 2.20
0.015″	0.381	2.17, 2.20
0.020″	0.508	2.17, 2.20
0.030″	0.762	2.17, 2.20
0.050″	1.270	2.17, 2.20
0.060″	1.524	2.17, 2.20
0.125″	3.175	2.17, 2.20
0.040″	1.016	2.40, 2.45, 2.50, 2.55, 2.60

Master sheet sizes include 36″ × 72″, 36″ × 48″, and 36″ × 36″. The 36″ × 72″ option is notably larger than most competing PTFE laminates offer as a standard format — relevant for phased array aperture boards and large combiner panels where maximizing usable area from a single sheet reduces fabrication waste and cost.

Note the 0.040″ thickness row where higher Dk options (2.40–2.60) are listed — this represents availability of the higher-glass-ratio DiClad 527 series at that specific thickness in the same product family ordering system.

Understanding DiClad 880’s Construction: Why Unidirectional Ply Matters

The fiberglass ply orientation is one of those details that engineers sometimes gloss over when pulling specs from a material comparison table. For DiClad 880, it’s worth understanding the implications.

The coated fiberglass plies in DiClad materials are aligned in the same direction. This unidirectional construction is distinct from the cross-plied architecture used in Arlon’s CuClad family. The consequence is that DiClad 880 has a small degree of electrical anisotropy — the Dk is marginally different depending on whether you’re measuring along the fiber direction or perpendicular to it. The magnitude of this anisotropy in practice is small, but in circuits where uniformity in all directions matters, it’s worth knowing.

What unidirectional construction gives you in return is superior Dk uniformity within-plane, along the fiber direction, and the absolute lowest loss achievable at a given Dk target. It also allows for larger sheet formats and somewhat simpler manufacturing process control compared to the precision alignment required for cross-plied construction.

The woven fiberglass reinforcement in DiClad products provides greater dimensional stability than nonwoven fiberglass-reinforced PTFE laminates of similar dielectric constants. The consistency and control of the PTFE-coated fiberglass cloth allows Arlon to produce a laminate with better Dk uniformity than comparable non-woven fiberglass-reinforced laminates. This matters on large panels — a Dk gradient across a 36″ × 48″ panel translates directly to performance variation across a large aperture antenna or a multi-channel power divider network.

DiClad 880 Performance Features: What the Numbers Mean in Practice

Extremely Low Loss Tangent — What 0.0009 Actually Buys You

The Df = 0.0009 at 10 GHz headline is worth translating into practical circuit terms. Dielectric loss contributes to total insertion loss in a transmission line alongside conductor loss. At microwave frequencies on a typical 50Ω microstrip, the dielectric loss per unit length is directly proportional to Df. Cutting Df from 0.020 (FR-4 level) to 0.0009 (DiClad 880) reduces the dielectric contribution to insertion loss by a factor of more than 20.

In a 10 GHz LNA front end, that difference between substrate losses is the difference between a commercially acceptable noise figure and a board that’s burning your system noise budget before the signal even reaches the first active device. In a long radar feed manifold distributing power across 64 elements, the cumulative insertion loss from substrate Df adds up at every branch and every inch of transmission line. DiClad 880’s 0.0009 Df is the right answer when you need to minimize that cumulative loss budget.

Electrical Properties Highly Uniform Across Frequency

One of DiClad 880’s explicitly listed benefits is that electrical properties are highly uniform across frequency. For wideband designs — swept-frequency filter characterization, multi-octave amplifiers, digital radio systems with wide instantaneous bandwidth — this stability simplifies design. If your substrate Dk drifts with frequency, your impedance calculations at the design center frequency don’t hold at the band edges. DiClad 880’s PTFE-based composition inherently produces a very flat Dk vs. frequency curve, which means the same design parameters work across your full frequency range.

Consistent Mechanical Performance and Chemical Resistance

Excellent chemical resistance and consistent mechanical performance are two properties that matter in harsh-environment electronics. PTFE is inherently resistant to most chemicals and solvents used in PCB fabrication and assembly — acid etches, flux residues, cleaning solvents. The material won’t absorb process chemicals that could alter its dielectric properties over time. In avionics, missile systems, and ground-based radar that may be exposed to fuel, hydraulic fluid, or cleaning agents, that chemical inertness is a real reliability advantage.

Arlon DiClad 880 Typical Applications

Military Radar Feed Networks

This is the application DiClad 880 was designed around. Radar feed networks — particularly the complex power distribution manifolds feeding phased array apertures — are among the highest-performance microwave circuits built on organic substrates. The combination of ultra-low loss (to maximize radiated power) and low Dk (to enable compact, high-impedance line widths on thin substrates) makes DiClad 880 the natural choice for this class of circuit.

Missile Guidance Systems

Missile guidance RF circuits face a compound specification challenge: they need to function across extreme temperature ranges (from cold storage through aerodynamic heating), survive high-g shock and vibration loads, and deliver precise electrical performance in a compact, lightweight package. DiClad 880’s chemical resistance, stable electrical properties, and consistent mechanical performance address all three axes of this challenge. Low water absorption means no dielectric property shift from humidity cycling during storage.

Commercial Phased Array Networks

Commercial phased array systems — including base station antenna arrays for cellular infrastructure and satellite ground terminals — need low-loss substrates at a price point compatible with commercial volume production. DiClad 880 occupies a favorable position here: it delivers near-maximum PTFE performance with the improved dimensional consistency of woven (rather than non-woven) fiberglass reinforcement, enabling tighter production tolerances on electrical performance without the cost premium of ceramic-filled PTFE systems.

Low Loss Base Station Antennas and Digital Radio Antennas

For base station antenna boards where insertion loss in the feed network translates directly to effective radiated power (and therefore to coverage or required PA power), substrate Df is a first-order design variable. DiClad 880 at Df = 0.0009 enables low-loss combiner networks that maximize the power actually reaching the radiating elements rather than dissipating it in the laminate.

Filters, Couplers, and Low Noise Amplifiers

DiClad laminates are frequently used in filter, coupler, and low noise amplifier applications where dielectric constant uniformity is critical. In bandpass filters, Dk uniformity across the panel is the primary determinant of center frequency repeatability from board to board. In couplers and LNAs, low loss is the critical variable. DiClad 880’s combination of high PTFE content (for low Df) and woven fiberglass reinforcement (for Dk uniformity) positions it as a natural choice for all three circuit types.

For a comprehensive overview of the full Arlon PCB material catalog — covering the entire range from woven PTFE laminates through ceramic-filled PTFE composites, polyimide systems, and high-speed epoxies — it’s valuable to understand DiClad 880 in the context of the complete Arlon portfolio.

Arlon DiClad 880 Within the DiClad Family

Understanding where DiClad 880 sits in the DiClad series helps you make confident material selection decisions:

DiClad Grade	Dk Range	Df (10 GHz)	Fiberglass/PTFE Ratio	Best For
DiClad 880	2.17 – 2.20	0.0009	Lowest	Ultra-low loss, fastest propagation
DiClad 870	~2.33	~0.0013	Medium	Balanced loss / mechanical properties
DiClad 522	2.40 – 2.65	~0.0015–0.0022	Higher	Better dimensional stability, conventional-like mechanicals
DiClad 527	2.40 – 2.65	~0.0015–0.0022	Higher	Better dimensional stability, lower thermal expansion

DiClad 880 and the DiClad 870 sit at the electrical performance end of the DiClad range — they sacrifice some mechanical robustness for the lowest achievable Dk and loss. DiClad 522 and 527 move in the other direction, using more fiberglass to gain mechanical stability and lower CTE, closer to conventional substrates in behavior if not quite there.

The practical selection rule: if lowest loss and Dk are the primary requirements, specify DiClad 880. If you need better mechanical stability and can tolerate slightly higher Dk and Df, DiClad 870 or the 522/527 family are the right steps up the mechanical stiffness ladder.

DiClad 880 vs. Competing Low-Dk Laminates

Engineers specifying DiClad 880 typically also evaluate Rogers RT/duroid 5880 and Taconic TLY-5. Here’s an honest comparison:

Parameter	Arlon DiClad 880	Rogers RT/duroid 5880	Taconic TLY-5
Dk (10 GHz)	2.17 / 2.20	2.20	2.17
Df (10 GHz)	0.0009	0.0009	0.0009
Construction	Unidirectional woven glass/PTFE	PTFE/microfiber glass	PTFE/woven glass
Dimensional stability	Good (woven reinforcement)	Moderate	Good
Dk uniformity	Excellent (woven control)	Good	Good
Max sheet size	36″ × 72″	30″ × 24″ std	Varies
Panel-level Dk consistency	Excellent	Good	Good

At the electrical property level, these three materials are essentially equivalent — all hitting Dk ≈ 2.17–2.20 and Df = 0.0009 at 10 GHz. The differentiation comes in manufacturing process, Dk uniformity control, sheet size availability, and supply chain considerations. DiClad 880’s woven fiberglass construction gives it a dimensional stability and Dk uniformity advantage over RT/duroid 5880’s microfiber glass construction. The larger available sheet sizes (36″ × 72″ for DiClad 880 vs. 30″ × 24″ standard for RT/duroid 5880) matter for large-format aperture boards.

Fabrication Guidelines for Arlon DiClad 880 PCBs

DiClad 880 is a PTFE-based material and requires PTFE-aware process controls throughout fabrication. The lower fiberglass content compared to DiClad 522/527 or CuClad 250 makes it somewhat softer and more susceptible to mechanical damage than higher-glass laminates, so process care is more important.

Drilling

Use highly polished carbide drill bits. Repointed (resharpened) drill bits are not recommended — even minor dulling on PTFE materials leads to tearing and smearing around the hole wall. DiClad 880’s low fiberglass content makes the laminate softer and more prone to drill-induced deformation than higher-glass PTFE products. Use appropriate entry and backup materials. Panels can be drilled in stacks, but keep total stack thickness within the limits your drill parameters are qualified for.

Surface Activation Before Plating and Bonding

PTFE is non-wetting by nature. Without surface activation, electroless copper will not adhere reliably to hole walls. Use inert gas plasma or sodium etch processes to activate PTFE surfaces before through-hole plating. Proceed to plating as quickly as practical after surface activation — the activated surface reverts toward its native non-wetting state over time (within a few hours). Adhesion to copper surfaces can be improved with an aggressive micro-etch such as ammonium persulfate prior to bonding in multilayer stacks.

Multilayer Bonding

PTFE multilayer stacks using DiClad 880 core laminates require compatible bonding materials. Options include Arlon’s thermoplastic bonding films (CuClad 6700, CuClad 6250) or the CLTE-P bonding ply for Dk-matched bonding layers. Standard epoxy prepreg is not a good choice for controlled-impedance microstrip or stripline designs through DiClad 880 core material — the Dk mismatch at the bondline will throw off your impedance calculations.

Routing and Edge Preparation

Use two-flute, slow-spiral, micrograin carbide upcut endmills for routing. The low fiberglass content of DiClad 880 makes it more susceptible to edge tearing than higher-glass PTFE laminates, so proper feed rate control and sharp tooling are especially important. Support the panel with rigid entry and backup materials.

Storage and Handling

Store flat in a cool, dry location away from direct sunlight. Avoid bending or flexing the material — the low fiberglass content makes DiClad 880 less rigid than conventional substrates, and repeated handling stress can cause micro-cracking in the PTFE matrix over time. Keep panels in their original packaging until ready for processing.

Useful Resources for Engineers Specifying DiClad 880

Resource	What You’ll Find	Where to Access
Arlon DiClad Datasheet (RS Online PDF)	Full DiClad family specs including DiClad 880 properties	docs.rs-online.com/9321/0900766b802b272f.pdf
Rogers DiClad 870/880 Product Page	Rogers-era product info and Laminate Properties Tool	rogerscorp.com/advanced-electronics-solutions/diclad-series-laminates/diclad-870_880-laminates
Arlon Microwave & RF Materials Guide	Full thickness/Dk availability tables, product family overview	integratedtest.com/wp-content/uploads/2021/08/ArlonMaterials.pdf
Fabrication Guidelines: DiClad, CuClad, IsoClad	PTFE process guidelines for drilling, bonding, routing	rfglobalnet.com/doc/fabrication-guidelines-arlon-diclad-cuclad-is-0001
MatWeb — Arlon DiClad 880	Material database entry for DiClad 880 properties	matweb.com
LookPolymers — DiClad 880	Condensed DiClad 880 property summary	lookpolymers.com
IPC-4103	Industry specification standard for PTFE-based laminates	ipc.org
Arlon EMD Laminate Design Guide	Comprehensive high-performance laminate selection guidance	arlonemd.com/wp-content/uploads/2020/05/Laminate-Guide.pdf

Always verify specifications from the current Rogers Corporation datasheet — Rogers acquired Arlon Circuit Materials in 2015, and the authoritative current spec documents are maintained under the Rogers brand.

Frequently Asked Questions About Arlon DiClad 880

Q1: What makes DiClad 880 different from DiClad 870?

Both are in the unidirectional woven fiberglass/PTFE DiClad product family, but they sit at different points on the fiberglass-loading spectrum. DiClad 880 uses a lower fiberglass/PTFE ratio, giving it a lower Dk (2.17 or 2.20 vs. DiClad 870’s approximately 2.33) and a lower Df. In practice, DiClad 880 gives you faster signal propagation speed and lower dielectric loss — the right choice when you need to squeeze every fraction of a dB out of your insertion loss budget or when propagation speed is a hard system requirement. DiClad 870’s medium glass loading delivers a modest step-up in mechanical stability at the cost of slightly higher Dk and Df. If your circuit can tolerate Dk ~2.33, DiClad 870 is somewhat easier to handle in fabrication.

Q2: Why is DiClad 880 specified in Dk values of 2.17 and 2.20 rather than a single fixed value?

The two nominal Dk options reflect different specific configurations of the material — the fiberglass weave density and PTFE coating process can be precisely controlled to produce two distinct nominal Dk target values within the same product family. Your design simulation should use the specific nominal Dk of the material you order, not an average. For the tightest impedance control, specify your required nominal Dk at order time and use that value in your transmission line calculations. The 2.17 option gives you the very lowest Dk in the DiClad family — the fastest signal propagation available in a woven-glass PTFE laminate.

Q3: Can DiClad 880 be used as a radome material?

Yes — DiClad laminates, including DiClad 880, are appropriate for radome and protective cover applications in addition to circuit substrates. The combination of low Dk (minimizing insertion loss through the radome), PTFE chemical inertness, and low water absorption makes woven PTFE laminates well-suited for antenna cover applications. The ultra-low Dk of DiClad 880 minimizes RF reflections and insertion loss at the radome surface, which matters in wideband applications.

Q4: Is DiClad 880 suitable for multilayer microwave PCBs?

Yes, but with more process complexity than using a ceramic-filled PTFE laminate like the CLTE family. DiClad 880’s low fiberglass content means the core laminates are somewhat softer and require careful handling in multilayer stack-up. Compatible bonding plies (Arlon CuClad 6700/6250 bonding films or CLTE-P prepreg for Dk-matched bondlines) are required — standard epoxy prepreg creates Dk discontinuities at bondlines that disrupt controlled impedance calculations. The lamination temperatures required for PTFE bonding plies are significantly higher than epoxy prepreg lamination, requiring presses with heat-and-cool-in-press capability.

Q5: How does DiClad 880’s Dk uniformity compare across a full panel?

DiClad 880’s woven fiberglass construction gives it significantly better panel-wide Dk uniformity than comparable non-woven fiberglass or microfiber-reinforced PTFE laminates. The consistency and control of the PTFE-coated fiberglass cloth allows Arlon to produce a laminate with better Dk uniformity than comparable non-woven fiberglass-reinforced laminates. In practical terms, this means that circuits patterned across a full 36″ × 48″ panel — large phased array aperture boards or multi-channel power divider networks — will see less center frequency variation and less impedance spread from position-to-position on the panel compared to non-woven PTFE alternatives. For defense production programs with tight electrical acceptance criteria, that within-panel uniformity translates directly to higher first-pass yield.

Suggested Meta Description:

Arlon DiClad 880 is a woven PTFE/fiberglass laminate with Dk 2.17–2.20 and Df 0.0009 at 10 GHz — the lowest loss in the DiClad series. Complete engineer’s guide covering DiClad 880 specs, datasheet, thickness options, fabrication guidelines, and applications in military radar, missile guidance, and phased array PCBs.

Everything you need to know about Arlon DiClad 870 — full electrical and mechanical specs, how it compares to DiClad 880 and DiClad 527, fabrication requirements for PTFE processing, and design tips for radar, base station, and phased array applications.

Every experienced RF PCB designer has run into the same compromise at some point: the substrate that gives you the best electrical numbers is often the one that causes the most headaches in fabrication and the most variance in production. DiClad 880 is a perfect example — Dk 2.17, dissipation factor as low as 0.0009 at 10 GHz, but soft, dimensionally challenging, and unforgiving if your fabricator’s PTFE process isn’t dialed in. Go the other direction toward DiClad 522 or 527 and you get excellent mechanical stability, but the Df creeps up to 0.0018.

Arlon DiClad 870 lives exactly in the middle. With a nominal Dk of 2.33 and a Df of 0.0013 at 10 GHz, it gives up a modest amount of loss performance compared to DiClad 880 in exchange for meaningfully better dimensional stability and mechanical robustness. For a very wide range of radar feed networks, base station antennas, LNA boards, and phased array circuits, that is a trade worth making — and DiClad 870 has a strong installed base in military and commercial high-frequency electronics to prove it.

This complete review covers the material composition, full specification profile, where DiClad 870 sits in the broader Arlon/Rogers DiClad family, what to watch for during fabrication, and how to use it well in real designs.

What Is Arlon DiClad 870?

Arlon DiClad 870 is a woven fiberglass reinforced, PTFE-based composite laminate originally developed by Arlon Materials for Electronics and now produced and marketed under the Rogers Corporation brand following Rogers’ acquisition of Arlon. It is part of the DiClad series — a family of PTFE/woven-glass composites distinguished by precise control of the fiberglass-to-PTFE content ratio across different products.

DiClad 870 uses a medium fiberglass-to-PTFE ratio, specifically engineered to reduce the dielectric constant and dissipation factor compared to the higher-glass DiClad 522/527 products, while retaining more dimensional stability than the very-high-PTFE DiClad 880. The result is a Dk of 2.33 — the same nominal value as Arlon CuClad 233 and IsoClad 933 — with a Df of 0.0013 at 10 GHz that clearly outperforms any thermoset laminate in its class.

One structural point worth establishing early: DiClad materials, including DiClad 870, use parallel-plied construction. All PTFE-coated fiberglass plies are aligned in the same direction. This distinguishes them from CuClad products, which use cross-plied construction for true X-Y isotropy. For most filter, coupler, power divider, and LNA board applications, parallel-plied construction is entirely adequate. Only when your design requires symmetric electrical behavior in orthogonal directions — certain phased array and balanced circuit topologies — does the parallel-plied construction of DiClad 870 become a constraint.

Working with quality Arlon PCB fabricators who have PTFE processing experience is essential when using DiClad 870 in production.

Arlon DiClad 870 Full Specification Table

The following table presents the typical electrical, mechanical, and environmental properties for Arlon DiClad 870. These are typical values from the Rogers/Arlon datasheet and published material databases. They are not to be used as specification limits. Always verify against the current official datasheet for your specific thickness and lot.

Property	Value	Test Method
Dielectric Constant (Dk) @ 10 GHz	2.33	IPC TM-650 2.5.5.5
Dissipation Factor (Df) @ 10 GHz	0.0013	IPC TM-650 2.5.5.5
Dissipation Factor (Df) @ 1 MHz, 50% RH	0.0009	IPC TM-650 2.5.5.3
Thermal Coefficient of Dk (TCDk)	-161 ppm/°C (-10 to 140°C)	IPC TM-650 2.5.5.7
CTE (X-axis)	17 ppm/°C	IPC TM-650 2.4.41
CTE (Y-axis)	29 ppm/°C	IPC TM-650 2.4.41
CTE (Z-axis)	217 ppm/°C	IPC TM-650 2.4.41
Moisture Absorption	0.02%	IPC TM-650 2.6.2
Copper Peel Strength (1 oz, 10s @ 288°C)	14 lbs/in	IPC TM-650 2.4.8
Arc Resistance	> 180 seconds	ASTM D495
UL Flammability Rating	UL94-V0	UL94
NASA Outgassing (TML)	0.01%	NASA SP-R-0022A
NASA Outgassing (CVCM)	0.01%	NASA SP-R-0022A
Ply Orientation	Parallel-plied	—
Construction Type	Woven fiberglass / PTFE composite	—

The 0.02% moisture absorption value is worth calling out specifically. This is among the lowest moisture absorption figures in the PTFE laminate category — genuinely exceptional performance for an outdoor or aerospace substrate. The NASA outgassing values (TML 0.01%, CVCM 0.01%) are similarly low, qualifying DiClad 870 for use in vacuum and space-adjacent environments where outgassing threatens optical or sensor performance.

Available Thickness Options for Arlon DiClad 870

DiClad 870 is available across a practical range of standard substrate thicknesses. The table below reflects standard configurations from the Arlon/Rogers materials guide.

Thickness (inches)	Thickness (mm)	Notes
0.010″	0.254	Thin, suitable for compact multilayer RF signal layers
0.020″	0.508	Most common for 2-layer microwave circuits
0.031″	0.787	Standard microstrip and stripline work
0.047″	1.194	Moderate substrate for LNA and coupler boards
0.062″	1.575	Common for power dividers and combiners
0.125″	3.175	Thick substrates, structural applications

Copper cladding is available in ½ oz, 1 oz, and 2 oz electrodeposited (ED) copper on both sides as standard offerings. Rolled annealed (RA) copper may be available on request and is worth considering for designs operating above 20 GHz, where the smoother surface profile of RA foil reduces conductor-dominated loss. Master sheet sizes are available up to 36″ × 72″, which supports multi-circuit panel layouts for volume production.

Understanding the Medium Fiberglass/PTFE Ratio in DiClad 870

The engineering principle that defines DiClad 870’s position in the DiClad family is worth understanding in practical terms, not just as a specification number.

Pure PTFE has a dielectric constant of approximately 2.1 and essentially no dielectric loss at microwave frequencies. As you add woven fiberglass reinforcement — which has a Dk in the 5–6 range — you raise the composite Dk and introduce a small amount of additional loss. You also gain dimensional stability, improved registration, and better mechanical handling. The fiberglass-to-PTFE ratio is therefore a tunable parameter that allows Arlon/Rogers to offer a range of PTFE-based products at different operating points.

DiClad 870 uses fewer plies of woven fiberglass and a higher ratio of PTFE content compared to DiClad 527 or DiClad 522, but more glass than DiClad 880. This produces a Dk of 2.33 — which is both lower and more electrically favorable than the DiClad 527 range of 2.40–2.65 — while preserving significantly better dimensional behavior than DiClad 880. The Df of 0.0013 at 10 GHz represents a clear improvement over DiClad 527’s 0.0018, and while it doesn’t quite match DiClad 880’s 0.0009, the gap is modest for the majority of application budgets.

In practical design terms, a system noise figure impact from the DiClad 870 vs. DiClad 880 loss difference is typically well under 0.1 dB for a few inches of transmission line at X-band — easily within normal design margin. What that step from DiClad 880 to DiClad 870 gets you in return is noticeably better panel-to-panel dimensional consistency and a substrate that is less likely to cause registration problems in multilayer builds or dimensional yield issues in high-volume antenna production.

Arlon DiClad 870 vs. DiClad 880 vs. DiClad 527: Choosing the Right Product

The most common material selection decision involving DiClad 870 is a three-way comparison with its immediate neighbors in the DiClad family. The table below lays out the key parameters side by side.

Parameter	DiClad 527	DiClad 870	DiClad 880
Nominal Dk @ 10 GHz	2.40 – 2.65	2.33	2.17 – 2.20
Df @ 10 GHz	0.0018	0.0013	~0.0009
Fiberglass/PTFE Ratio	Higher glass	Medium glass	Lower glass
CTE X-axis (ppm/°C)	~14	17	Higher
Moisture Absorption	0.03%	0.02%	Higher
Dimensional Stability	Best in series	Good	Lower
Mechanical Robustness	Most robust	Good	Softer
Ply Orientation	Parallel	Parallel	Parallel
Best Application Fit	High-vol production, stability	Balanced loss + stability	Lowest loss priority

The decision between DiClad 870 and DiClad 880 almost always comes down to loss budget versus fabrication risk. If your system noise figure analysis shows that Df 0.0009 is genuinely required to meet the specification — common in precision receive chains for scientific instruments, some defense radar systems, or very long-run test fixtures — then DiClad 880 is the right choice and you should work with a fabricator who regularly processes very-high-PTFE substrates. If the 0.0013 Df of DiClad 870 achieves your loss budget with margin to spare, the improved dimensional stability and slightly better moisture performance make DiClad 870 the more practical and reliable production choice.

The choice between DiClad 870 and DiClad 527 is generally straightforward: DiClad 870 has better electrical performance (lower Dk and lower Df) at the cost of slightly reduced dimensional stability versus DiClad 527. If your application demands the better loss numbers and your fabricator is comfortable with PTFE processing, DiClad 870 is the right move. If you’re in a high-volume production environment where dimensional yield drives unit economics, DiClad 527 may win even though its Df is 38% higher.

How Arlon DiClad 870 Compares to Other Brands at Dk 2.33

DiClad 870 is not the only product targeting the Dk 2.33 market. The following comparison helps position it against frequently considered alternatives.

Material	Manufacturer	Dk	Df @ 10 GHz	Ply Type	Notes
DiClad 870	Rogers/Arlon	2.33	0.0013	Parallel	Medium PTFE, balanced
CuClad 233	Rogers/Arlon	2.33	0.0013	Cross-plied	X-Y isotropic version of same Dk
IsoClad 933	Rogers/Arlon	2.33	~0.0015	Non-woven random	Flexible/conformal applications
Rogers RT/duroid 5870	Rogers	2.33	0.0012	PTFE/microfiber	Non-woven, similar Df
Rogers RO4003C	Rogers	3.55	0.0027	Thermoset	Much higher Dk, not directly comparable
Standard FR4	Various	4.2–4.5	> 0.020	Thermoset	Not suitable above ~1 GHz

DiClad 870 and CuClad 233 share the same Dk and very similar Df, but the construction differs. CuClad 233 uses cross-plied construction for X-Y isotropy, making it the preferred choice when true isotropy is needed. DiClad 870’s parallel-plied construction provides better Dk uniformity in the laminate plane along the fiber direction, which can be advantageous for circuits that predominantly run in one direction. For most standard filter, LNA, and coupler designs, either material performs equivalently and the choice may come down to panel format preferences or fabricator experience.

Typical Applications for Arlon DiClad 870

DiClad 870’s application profile reflects its balanced position in the DiClad family: low enough loss for demanding RF circuits, stable enough for production-level manufacturing and outdoor/field deployments.

Application Category	Specific Use Cases
Military Radar	Radar feed networks, T/R module substrates, AESA aperture distribution boards
Missile Guidance	RF front-end substrates in guidance and seeker systems
Phased Array Networks	Commercial phased array antenna circuits at X-band and below
Base Station Antennas	Low-loss base station feed networks and LNA boards
Satellite Communications	Uplink and downlink passive networks where outgassing matters
Digital Radio Systems	DAB and digital radio antenna circuits
Passive Microwave	Bandpass filters, hybrid couplers, Wilkinson dividers, LNA matching networks
Space Applications	Outgassing-qualified substrates for near-space or satellite hardware

The missile guidance application is one where DiClad 870’s combination of properties aligns particularly well. Guidance systems require not just low loss for clean signal reception, but also vibration and shock resistance, wide operating temperature range, and long shelf-life stability. DiClad 870 is a soft substrate relative to ceramics, which means it handles shock and vibration loads without cracking. Its 0.02% moisture absorption ensures the Dk doesn’t shift measurably over years of storage. The wide arc resistance (>180 seconds) provides an additional reliability margin in high-voltage-adjacent circuits.

Arlon DiClad 870 PCB Design Considerations

Trace Width and Impedance Calculation

Dk 2.33 produces wider traces for a given impedance on a given substrate thickness compared to higher-Dk materials. For a 50-ohm microstrip on 0.031″ DiClad 870, the trace width is considerably wider than on Rogers RO4003C at the same thickness. This is generally advantageous — wider lines have lower resistive loss and are easier to manufacture within tolerance — but it does require accurate calculation. Always use the correct Dk value in your transmission line calculator. Do not assume Dk 2.33 is a fixed single number across all thicknesses; verify the datasheet value for your specific substrate thickness and order specification.

Dielectric Constant Stability Across Frequency

One of PTFE’s defining advantages is Dk stability across frequency. DiClad 870 maintains a consistent Dk from 1 MHz through well into the millimeter-wave range. This means a design computed at your center frequency will behave predictably across the full operating band without frequency-dependent Dk corrections. For broadband circuit designs — octave-bandwidth amplifiers, wideband limiters, multi-octave filters — this property eliminates a significant category of simulation uncertainty.

Thermal Coefficient of Dk (TCDk) in Temperature-Sensitive Designs

DiClad 870 has a TCDk of -161 ppm/°C across the -10°C to 140°C temperature range at 10 GHz. The negative sign means the Dk decreases as temperature increases — the material becomes electrically “faster” at elevated temperatures. For phased array feed networks where phase consistency must be maintained across a military temperature range, this TCDk will produce a measurable shift in electrical phase length. Include this effect in your thermal-electrical budgeting. If the TCDk of DiClad 870 causes too much phase variation in your specific design, Arlon’s CLTE series (ceramic-filled PTFE with improved TCDk) is worth evaluating as an alternative.

Z-Axis CTE and Via Reliability

With a Z-axis CTE of 217 ppm/°C, DiClad 870 shows a high thermal expansion in the through-board direction — a property shared by all PTFE-based laminates. Copper’s CTE is approximately 17 ppm/°C, so the mismatch between the expanding PTFE dielectric and the copper barrel in a plated through-hole is significant during thermal cycling. To manage this, keep via aspect ratios below 8:1 where possible, specify conservative drill-to-pad ratios for reliable annular ring coverage, and consider blind or buried vias for signal-layer connections in multilayer stackups where the full board thickness does not need to be traversed.

Wider Line Widths and Their Effect on Conductor Loss

An often-underappreciated benefit of DiClad 870’s low Dk is that the wider trace widths required for a given impedance directly reduce resistive conductor loss. At X-band and above, conductor losses in microstrip can dominate over dielectric losses on PTFE-based substrates. A wider trace cross-section lowers the conductor loss per unit length. This is why DiClad 870’s datasheet specifically notes that the stable, low Dk supports wider line widths for lower insertion loss — it’s not just a material property note, it’s a practical circuit performance advantage.

Fabrication Guidelines for Arlon DiClad 870

Material Handling and Storage

Store DiClad 870 panels in a clean, temperature- and humidity-controlled environment. Moisture absorption is very low at 0.02%, but surface contamination from fingerprints, particulates, or chemical exposure will affect plating adhesion and lamination quality. Handle panels with clean gloves and process promptly after removing from protective packaging.

Drilling Requirements

Use fresh carbide drill bits and limit drill stack heights to one or two panels. Worn tooling is the most common cause of PTFE smear in drilled holes. Use appropriate aluminum entry material and backup material to support clean hole entry and breakthrough. Inspect hole walls before proceeding to surface activation and plating.

PTFE Hole Wall Activation — Non-Negotiable

This is the process step that separates fabricators who genuinely know PTFE from those who are guessing. PTFE is chemically inert and will not form a reliable bond with electroless copper without activation. The two standard methods are sodium naphthalate (or sodium ammonia) chemical etching and plasma etch. Both roughen and chemically modify the PTFE hole wall surface to create adhesion sites for the copper deposit. Skipping or under-performing this step produces plated through-holes that pass initial electrical testing but fail under thermal cycling — often dramatically and catastrophically.

Before selecting a fabricator, ask directly: what PTFE activation method do you use, and how do you validate activation quality? If the answer is vague or the fabricator cannot confirm this is a standard step in their process, that is a serious disqualification for DiClad 870 production.

Etching, Assembly, and Soldering

Standard cupric chloride or ammoniacal etchants are fully compatible with DiClad 870’s electrodeposited copper. The copper peel strength of 14 lbs/in provides good support for fine-line etching. DiClad 870 is lead-free process compatible and handles standard SMT reflow profiles without issue. The 0.02% moisture absorption means essentially no moisture is present to outgas and cause solder splash or delamination during reflow. Profile your oven for the actual thermal mass of the board — PTFE laminates conduct heat differently from FR4.

Common Design and Production Pitfalls with Arlon DiClad 870

Confusing DiClad 870 with DiClad 880 in documentation. The two products have similar names and sit adjacent in the DiClad series. DiClad 870 is Dk 2.33, DiClad 880 is Dk 2.17–2.20. Using the wrong Dk in your transmission line calculations from the outset propagates an impedance error through the entire design. Double-check your material call-out on the PCB fabrication drawing against the intended substrate.

Neglecting TCDk in outdoor or wide-temperature designs. At -161 ppm/°C, a 100°C temperature swing shifts the Dk by approximately 0.037. For a tuning-sensitive circuit like a narrowband combline filter at 10 GHz, this drift can produce several MHz of center frequency shift between summer and winter outdoor conditions. Model this into your design simulation with temperature as a swept variable.

Assuming DiClad 870 can be processed exactly like FR4. The PTFE activation step and PTFE-compatible bonding ply selection in multilayer builds are not optional accommodations — they are fundamental requirements. An FR4 fabricator who applies FR4 process parameters to DiClad 870 will produce boards with marginal or failed PTH reliability, even if the boards appear electrically functional off the assembly line.

Not verifying sheet-to-sheet Dk consistency. For precision RF circuits where impedance tolerance is tight, request Dk test data for the specific lot of material being used. Standard production testing covers sampling, not every sheet. If your circuit is sensitive to lot-to-lot Dk variation — as a narrow-bandwidth filter would be — consider specifying individual-sheet test reporting, similar to the LX grade available on CuClad products.

Useful Resources for Arlon DiClad 870 Engineers

Resource	Description	Link
Rogers DiClad 870/880 Product Page	Official Rogers/Arlon product page with property sampling	rogerscorp.com
DiClad Series Datasheet (RS Online)	Complete DiClad family datasheet covering all variants	docs.rs-online.com
Arlon Microwave & RF Materials Guide	Full DiClad product comparison table with CTE, outgassing, and more	integratedtest.com PDF
MatWeb DiClad 870 Entry	Material database entry with all DiClad 870 properties	MatWeb
Rogers Laminate Properties Tool	Interactive comparator for all Rogers laminate families	rogerscorp.com tools
IPC TM-650 Test Methods	Standard test methods referenced in the DiClad 870 datasheet	ipc.org
Arlon Laminate Guide PDF	Arlon laminate technical guide covering PTFE processing	arlonemd.com
RayPCB Arlon PCB Resource	Fabrication resource for Arlon high-frequency PCB materials	RayPCB Arlon PCB

5 Frequently Asked Questions About Arlon DiClad 870

1. What is the main difference between Arlon DiClad 870 and DiClad 880?

Both are PTFE/woven fiberglass laminates from the same Rogers/Arlon family, but they target different points in the loss-versus-stability trade-off. DiClad 870 has a nominal Dk of 2.33 and a Df of 0.0013 at 10 GHz, while DiClad 880 drops to Dk 2.17–2.20 and Df approximately 0.0009 at 10 GHz by using a higher PTFE content. DiClad 870 compensates with better dimensional stability, slightly lower moisture absorption (0.02% vs. DiClad 880’s slightly higher value), and better mechanical handling. For most practical high-frequency applications, DiClad 870’s loss performance is entirely sufficient, and its better processability makes it the more production-friendly choice.

2. Is Arlon DiClad 870 appropriate for space or satellite applications?

Yes. DiClad 870 qualifies for space-adjacent applications based on its NASA outgassing data: Total Mass Loss (TML) of 0.01% and Collected Volatile Condensable Materials (CVCM) of 0.01%. Both values are well within the NASA outgassing threshold typically required for satellite hardware (TML < 1.0%, CVCM < 0.1%). The extremely low moisture absorption of 0.02% also supports long shelf life and stable performance in vacuum environments where absorbed moisture would otherwise outgas and potentially affect nearby optical or sensor surfaces.

3. Can Arlon DiClad 870 be used in multilayer PCB stackups?

Yes. DiClad 870 can be used in multilayer designs, but it requires PTFE-compatible bonding materials — not standard FR4 prepregs. Use Rogers-specified bonding films or PTFE bondply materials designed for high-frequency multilayer construction. The Z-axis CTE of 217 ppm/°C must be considered in via reliability calculations, particularly for through-board vias in applications with wide thermal cycling. Blind and buried via constructions help manage the CTE mismatch by limiting barrel length.

4. What surface finishes are compatible with Arlon DiClad 870?

Standard surface finishes used with PTFE-based PCBs are compatible with DiClad 870. These include ENIG (Electroless Nickel Immersion Gold), immersion silver, immersion tin, and ENEPIG. HASL (Hot Air Solder Leveling) is generally not recommended for PTFE laminates because the high-temperature tin-lead or lead-free solder bath can cause localized thermal damage. For microwave circuits where surface roughness affects conductor loss at higher frequencies, ENIG is often preferred because the controlled gold thickness provides a clean, consistent microstrip surface.

5. How does Arlon DiClad 870 perform at millimeter-wave frequencies above 30 GHz?

PTFE’s inherent Dk stability across frequency means DiClad 870 maintains consistent dielectric properties well into the millimeter-wave range. However, as frequency rises above 20–30 GHz, conductor-dominated loss increasingly outweighs dielectric loss even on an excellent substrate like DiClad 870. At these frequencies, the copper surface roughness becomes the dominant loss mechanism. For mmWave designs on DiClad 870, specify low-profile or rolled annealed copper foil rather than standard electrodeposited copper, and include a copper roughness correction factor in your EM simulation insertion loss predictions. The Df of 0.0013 remains low enough to be a minor contributor to total insertion loss well through Ka-band.

Final Thoughts on Arlon DiClad 870

Arlon DiClad 870 is a material that rewards engineers who take the time to understand what “medium fiberglass/PTFE ratio” actually delivers in practice. The Dk 2.33 and Df 0.0013 at 10 GHz are strong numbers — genuinely competitive with anything in the PTFE laminate category at this Dk level. The 0.02% moisture absorption and qualified NASA outgassing performance extend its usefulness well beyond indoor electronics into outdoor infrastructure, airborne systems, and satellite hardware.

What DiClad 870 asks in return is a fabrication partner who takes PTFE processing seriously: proper hole wall activation, PTFE-compatible bonding materials for multilayer builds, and appropriate drilling parameters. With the right fabricator, these are not difficult requirements. They’re just different from FR4.

For RF and microwave engineers evaluating laminate choices in the Dk 2.2–2.5 range, DiClad 870 should be a standard candidate on any comparison shortlist. In many cases — especially where the design must perform reliably across temperature, humidity, and years of field service — it will be the final answer.

Complete engineering guide to Arlon DiClad 527 — electrical and mechanical specs, DiClad 527 vs 522 comparison, fabrication requirements, NASA outgassing data, and application guide for RF and microwave PCB designers.

There’s a recurring dilemma in microwave PCB design that most RF engineers know well: you need low loss for your circuit to perform, but you also need a substrate that doesn’t fight you at every step of the fabrication process. Very high-PTFE-content laminates like DiClad 880 or CuClad 217 offer exceptional electrical properties, but they’re soft, dimensionally tricky, and require fabricators who know exactly what they’re doing. On the other side, standard thermoset materials like RO4003 are far easier to process but can’t match the loss performance of PTFE at higher frequencies.

Arlon DiClad 527 occupies a deliberate middle position in this landscape. It’s a woven fiberglass reinforced, PTFE-based composite laminate that prioritizes dimensional stability and mechanical robustness without abandoning the low-loss credentials that make PTFE materials worth the trouble. Understanding where DiClad 527 fits, what it delivers, and how to design and fabricate with it is what this guide is for.

What Is Arlon DiClad 527?

Arlon DiClad 527 is a woven fiberglass reinforced PTFE-based composite material designed for use as a printed circuit board substrate in high-frequency and microwave applications. It belongs to the DiClad product family originally developed by Arlon Materials for Electronics — now part of Rogers Corporation following Rogers’ acquisition of Arlon LLC.

The defining design principle behind DiClad 527 is its high fiberglass-to-PTFE ratio. This ratio is precisely controlled to push the material toward greater dimensional stability, better registration, and mechanical behavior that approaches conventional PCB substrates, while still maintaining the low loss properties inherent to PTFE-based systems. The Dk range of 2.40 to 2.65 reflects this compromise: slightly higher than the ultra-pure PTFE end of the spectrum (Dk ~2.1), but significantly lower than any thermoset or ceramic-filled material.

An important distinction to understand about DiClad 527 compared to its CuClad counterparts is ply orientation. The coated fiberglass plies in DiClad materials are aligned in the same direction — this is parallel-plied construction, not cross-plied. If your application requires true X-Y isotropy (as some phased array antenna designs do), you’d need to look at the CuClad family instead. But for the majority of filter, coupler, LNA, and power divider applications where single-direction dimensional stability is the priority, parallel-plied DiClad 527 is often the better practical choice.

For engineers looking at the full spectrum of Arlon PCB materials, DiClad 527 represents the high-stability end of the DiClad series for the 2.4–2.65 Dk range.

Arlon DiClad 527 Key Specifications

The table below presents the typical electrical and mechanical properties for Arlon DiClad 527. These are typical values and should not be used as specification limits. Always verify against the current Rogers/Arlon datasheet for your specific thickness and application.

Property	Value	Test Method
Dielectric Constant (Dk) @ 10 GHz	2.40 – 2.65	IPC TM-650 2.5.5.5
Dissipation Factor (Df) @ 10 GHz	0.0018	IPC TM-650 2.5.5.5
Dielectric Constant @ 1 MHz	2.40 – 2.65	IPC TM-650 2.5.5.3
Thermal Coefficient of Er (TCDk)	-153 ppm/°C	IPC TM-650 2.5.5.7
CTE (X-axis)	~14 ppm/°C	IPC TM-650 2.4.41
CTE (Y-axis)	~21 ppm/°C	IPC TM-650 2.4.41
CTE (Z-axis)	~173 ppm/°C	IPC TM-650 2.4.41
Tensile Modulus	706 kpsi	ASTM D882
Water Absorption	0.03%	IPC TM-650 2.6.2
Specific Gravity	2.31 g/cm³	ASTM D792
Thermal Conductivity	~0.254 W/m·K	ASTM E1461
UL Flammability Rating	UL94-V0	UL94
NASA Outgassing (TML)	0.02%	NASA SP-R-0022A
NASA Outgassing (CVCM)	0.00%	NASA SP-R-0022A
Typical Peel Strength (1 oz Cu)	≥ 14 lbs	IPC TM-650 2.4.8

Two numbers in that table deserve special attention. The water absorption of just 0.03% is remarkably low — even by PTFE standards — and it has real-world consequences in base station antenna and outdoor radar applications where long-term moisture stability is critical. The NASA outgassing data (essentially zero CVCM) also explains why DiClad 527 shows up in satellite and space-adjacent programs where outgassing is a qualification constraint.

Available Thickness and Dk Options for Arlon DiClad 527

One of DiClad 527’s practical advantages is its wide range of available thicknesses, starting from very thin substrates that are useful in compact multilayer RF stackups. The table below summarizes standard configurations from the Arlon/Rogers materials guide.

Thickness (inches)	Thickness (mm)	Available Dk Options
0.005″	0.127	2.50, 2.55
0.010″	0.254	2.45, 2.50, 2.55, 2.60
0.015″	0.381	2.45, 2.50, 2.55
0.020″	0.508	2.45, 2.50, 2.55, 2.60
0.031″	0.787	2.45, 2.50, 2.55, 2.60
0.047″	1.194	2.50, 2.55, 2.60
0.062″	1.575	2.45, 2.50, 2.55, 2.60
0.125″	3.175	2.50, 2.55, 2.60

Master sheet sizes are available in 36″ × 72″, 36″ × 48″, and 36″ × 36″. The range of available sheet sizes, combined with the wide thickness offering, makes DiClad 527 well suited for multi-circuit panel layouts and moderate-to-high volume production runs.

Copper cladding is available in ½ oz, 1 oz, and 2 oz electrodeposited (ED) copper. For fine-line or millimeter-wave designs where conductor surface roughness becomes a dominant loss mechanism, rolled annealed (RA) copper may be available on request and is worth specifying.

Understanding the DiClad 527 Fiberglass-to-PTFE Ratio Design Philosophy

To design well with DiClad 527, it helps to understand what the high fiberglass-to-PTFE ratio actually buys you — and what it costs you.

Pure or near-pure PTFE laminates like DiClad 880 deliver the lowest possible loss (Df approaching 0.0009 at 10 GHz) and the lowest Dk (~2.17), but the high PTFE content makes the material soft and dimensionally challenging. Etching-induced dimensional change is larger, registration in multilayer builds is harder to control, and the boards require more care in handling during fabrication. For a one- or two-layer prototype in a research lab, this is manageable. For a high-volume production run of base station antenna boards, it’s a real manufacturing risk.

DiClad 527 adds significantly more fiberglass reinforcement compared to DiClad 880 or DiClad 870. DiClad 522 and DiClad 527 use a higher fiberglass/PTFE ratio to provide mechanical properties approaching conventional substrates. Other advantages include better dimensional stability and lower thermal expansion in all directions. The tradeoff is a Df of 0.0018 at 10 GHz rather than 0.0009 — roughly double the dielectric loss. For most base station antenna, radar feed network, and LNA applications, 0.0018 is still excellent performance, and the dimensional stability benefits are very much worth it.

The consistency and control of the PTFE-coated fiberglass cloth is the other key quality attribute. The woven fiberglass reinforcement in DiClad products provides greater dimensional stability than nonwoven fiberglass reinforced PTFE based laminates of similar dielectric constants. The consistency and control of the PTFE coated fiberglass cloth allows Arlon to offer a greater variety of dielectric constants and produces a laminate with better dielectric constant uniformity than comparable non-woven fiberglass reinforced laminates. Dk uniformity within a panel is not just a comfort specification — it directly affects the yield of tuning-sensitive circuits like bandpass filters and branch-line hybrids.

Arlon DiClad 527 vs. DiClad 522: Key Differences

DiClad 527 is frequently paired with DiClad 522 in documentation, and engineers new to the DiClad family often ask what distinguishes them. Both share the same Dk range (2.40–2.65) and application profile, but they are distinct products used in complementary ways.

Parameter	DiClad 522	DiClad 527
Dk Range @ 10 GHz	2.40 – 2.60	2.40 – 2.65
Dissipation Factor @ 10 GHz	0.0018	0.0018
Thinnest Available	0.015″	0.005″
Thickest Available	0.250″	0.125″
Best Fit	Thicker single-layer boards, power circuits	Thin RF circuits, multilayer builds
Ply Orientation	Parallel-plied	Parallel-plied
Water Absorption	0.03%	0.03%

The most practical difference between the two is the thickness range. DiClad 527 goes down to 0.005″ (0.127 mm), making it the right choice when you need a thin dielectric for compact impedance-controlled lines or when you’re building a multilayer stackup with thin RF signal layers. DiClad 522 covers the thicker range and goes up to 0.250″, which is advantageous for substrates that double as structural elements in outdoor antenna housings or power amplifier boards.

In many multilayer designs combining DiClad materials, DiClad 527 provides the thin inner signal layers while DiClad 522 serves as a thicker core or outer layer. Both are processed using the same PTFE-based fabrication approach.

Arlon DiClad 527 Compared to Other High-Frequency Laminates

Choosing between DiClad 527 and competitive or sibling materials comes down to understanding the performance and processability trade-offs in your specific application.

Material	Nominal Dk	Df @ 10 GHz	Mechanical Stability	Best Application
Arlon DiClad 880	2.17 – 2.20	~0.0009	Lower	Lowest loss priority
Arlon DiClad 870	2.33	~0.0013	Medium	Balanced Dk/loss
Arlon DiClad 527	2.40 – 2.65	0.0018	High	Stable production, base station
Rogers RT/duroid 5880	2.20	0.0009	Lower	Lowest loss, lab/defense
Rogers RO4003C	3.55	0.0027	Very High	Thermoset, volume production
Standard FR4	4.2 – 4.5	>0.020	Very High	Not suitable for microwave

DiClad 527 delivers a loss performance that is roughly 3× better than RO4003C at 10 GHz, while offering mechanical stability that is considerably better than RT/duroid 5880 or DiClad 880. For applications where the antenna gain budget or filter insertion loss specification is tight but where production volumes and fabrication yield also matter, DiClad 527 hits a genuinely useful operating point that neither the ultra-low-loss nor the thermoset materials can match.

Typical RF and Microwave Applications for Arlon DiClad 527

The application set for DiClad 527 is well defined by its combination of low loss, excellent dimensional stability, very low moisture absorption, and favorable outgassing behavior.

Application Category	Specific Use Cases
Military & Defense	Radar feed networks, missile guidance RF circuits, electronic warfare receive chains
Phased Array Systems	Commercial phased array antenna feed networks (radar, comms, AESA)
Cellular Infrastructure	Low-loss base station antenna feed networks, tower-top LNA boards
Satellite & Space	Uplink/downlink microwave circuits where outgassing is a constraint
Digital Radio & Broadcasting	DAB, satellite radio antenna circuits and combiners
Passive RF Components	Filters, directional couplers, power dividers, hybrid couplers, LNAs

The low moisture absorption of 0.03% deserves emphasis in the base station context. Outdoor antenna systems experience temperature cycling, condensation, and long-term humidity exposure. A substrate that absorbs moisture changes its Dk, which shifts the resonant frequency of antenna elements and the center frequency of filters. DiClad 527’s near-zero moisture absorption gives antenna designers confidence that the RF performance they characterize in the lab will be maintained across years of field deployment.

The NASA outgassing data (TML 0.02%, CVCM 0.00%) is equally significant for satellite and space-adjacent applications. Outgassing in vacuum can contaminate optical surfaces and sensitive detector materials. DiClad 527 meets the threshold that satellite programs typically impose.

PCB Design Considerations for Arlon DiClad 527

Impedance Control and Trace Width Calculation

A Dk range of 2.40–2.65 rather than a single fixed value is the most important design consideration for trace width calculation. Unlike a thermoset material with a tight, fixed Dk, DiClad 527’s Dk depends on the specific Dk option ordered and the actual fabricated laminate thickness. Always use the actual Dk value for the specific sub-grade you are ordering (e.g., 2.50, 2.55, or 2.60) rather than a midpoint assumption.

For a 50-ohm microstrip on DiClad 527 at Dk 2.55 and 0.031″ substrate thickness, the required trace width will be significantly different from the same circuit on FR4. Use an accurate electromagnetic field solver or a validated transmission line calculator with the correct Dk and substrate thickness. Do not copy trace widths from FR4 designs.

Dk Stability Across Frequency

One of the well-known advantages of PTFE-based materials is how stable the dielectric constant is across frequency. DiClad 527, like all DiClad and CuClad materials, maintains essentially flat Dk from 1 MHz through the microwave range. This simplifies wideband circuit design — you don’t need to apply frequency-dependent Dk corrections to your simulation, and the impedance behavior you compute at your center frequency is representative of the full operating band.

Managing TCDk in Temperature-Sensitive Designs

DiClad 527 has a thermal coefficient of Er (TCDk) of approximately -153 ppm/°C. This means the dielectric constant decreases as temperature increases. For precision phase-matching applications — phased array feed networks where beam pointing accuracy depends on consistent electrical phase — this temperature-induced Dk shift can produce measurable beam squint at temperature extremes. Budget the TCDk into your system-level analysis for any phase-sensitive application.

Z-Axis CTE and Via Reliability

At approximately 173 ppm/°C in the Z-axis, DiClad 527’s Z-axis CTE is much higher than copper (~17 ppm/°C). This CTE mismatch drives barrel fatigue in plated through-holes during thermal cycling. For multilayer DiClad 527 boards used in environments with wide temperature swings — outdoor base station electronics, airborne radar systems — keep via aspect ratios low (ideally below 8:1), avoid excessively long barrel lengths, and consider the use of micro-via or blind via constructions for signal layers where possible.

Fabrication Guidelines for Arlon DiClad 527

Processing DiClad 527 is a different discipline from FR4 fabrication. The material’s PTFE base brings several process-specific requirements that must be followed to achieve reliable, high-yield boards.

Cutting and Panel Preparation

DiClad 527’s higher fiberglass content compared to DiClad 880 makes it somewhat more forgiving to cut and shear than ultra-soft PTFE laminates, but it is still a PTFE composite. Use sharp tooling and maintain clean cutting surfaces. Store panels in a controlled environment — temperature- and humidity-stable — and process them promptly after unpacking to minimize surface contamination that can affect subsequent processing steps.

Drilling

Drill at low stack heights — one to two panels maximum per stack. Use carbide drill bits with sharp cutting edges, and use appropriate entry and exit materials to support clean hole walls at entry and break-through. Inspect drilled hole walls before plating. PTFE smear inside holes — caused by heat buildup from dull tooling or excessive feed rates — is a leading cause of plated through-hole reliability failure in PTFE-based laminates.

PTFE Hole Wall Activation

This is the most critical process step unique to PTFE laminates. PTFE is chemically inert and will not bond to electroless copper without surface activation. Before electroless copper deposition, every hole wall must be treated with either a sodium naphthalate chemical etch or a plasma etch process to roughen and activate the PTFE surface. Skipping or under-performing this step causes plated through-holes that appear acceptable visually but fail under thermal cycling due to poor adhesion between the PTFE surface and the copper deposit.

Confirm with your fabricator specifically which PTFE activation process they use and how they validate it. This should be a standard qualification question, not an afterthought.

Etching and Copper Processing

Standard cupric chloride or ammoniacal etchants are compatible with DiClad 527’s electrodeposited copper foils. Peel strength for 1 oz copper on DiClad 527 is typically above 14 lbs/inch, which is good for fine-line processing. Handle etched panels carefully — while DiClad 527 is more mechanically robust than DiClad 880, it is still more susceptible to edge damage than a thermoset laminate.

Multilayer Lamination

Bonding DiClad 527 cores into multilayer structures requires PTFE-compatible bonding plies. Standard FR4 prepregs are not appropriate. Use Rogers-specified bonding films or PTFE-based bonding plies designed for high-frequency multilayer construction. Follow the bonding film supplier’s recommended temperature and pressure profiles precisely — deviations lead to non-uniform bond line thickness, which directly causes impedance variation across the panel.

Assembly and Soldering

DiClad 527 is lead-free process compatible and conforms to IEC 61249-2-21. Standard SMT reflow profiles are compatible with the material. The low water absorption of 0.03% means there is virtually no risk of moisture-induced delamination or solder splashing during reflow. Profile your oven based on the actual thermal behavior of the populated board — PTFE laminates distribute heat differently from FR4 due to lower thermal conductivity.

Common Pitfalls When Working with Arlon DiClad 527

Specifying an incorrect Dk for trace width calculation. DiClad 527 is available in multiple Dk sub-grades (2.45, 2.50, 2.55, 2.60, 2.65). Using a generic “2.5” value when your actual ordered material is 2.60 introduces an impedance error that accumulates across all transmission lines in the design. Confirm the exact Dk specification at the time of ordering and use that value in your models.

Applying parallel-plied dimensions to a cross-plied assumption. DiClad 527 uses parallel-plied construction — all fiberglass plies run in the same direction. The material is not isotropic in the X-Y plane. This is generally not a problem for most microwave circuit topologies, but if your design relies on equal electrical behavior in orthogonal orientations (certain balanced antenna designs, for example), DiClad 527 is the wrong material choice. Use CuClad 250 instead for cross-plied construction at a similar Dk.

Not qualifying the PTFE activation step. The sodium etchant or plasma activation step before electroless copper is not optional. Fabricators who primarily process thermoset materials may not have this step in their standard process flow. Verify it explicitly before awarding a job.

Ignoring moisture effects on long-term field deployment. DiClad 527’s 0.03% water absorption is excellent, but it is not zero. For very long service life outdoor antenna applications (15+ years), understand the encapsulation and sealing of the final assembly and verify that the board is not exposed to prolonged standing water.

Useful Resources for Arlon DiClad 527 Engineers

Resource	Description	Link
Rogers DiClad 527 Product Page	Official Rogers/Arlon product page with data sampling	rogerscorp.com
Arlon Microwave & RF Materials Guide	Full DiClad series comparison tables and specifications	integratedtest.com PDF
DiClad Series Datasheet (RS Online)	DiClad 880, 870, 522, 527 full property tables	docs.rs-online.com
MatWeb DiClad 522/527 Entry	Material property database with unit conversions	MatWeb
LookPolymers DiClad 527 Entry	Material summary with typical applications	lookpolymers.com
Rogers Laminate Properties Tool	Interactive sorting and comparison of Rogers laminate properties	rogerscorp.com tools
IPC TM-650 Test Methods	Standard test methods referenced in the DiClad 527 datasheet	ipc.org
RayPCB Arlon PCB Guide	Fabrication guidance for Arlon PCB material families	RayPCB Arlon PCB

5 Frequently Asked Questions About Arlon DiClad 527

1. What is the difference between Arlon DiClad 527 and Rogers RT/duroid 5880?

Both are woven fiberglass reinforced PTFE laminates, but they serve different performance priorities. RT/duroid 5880 has a Dk of 2.20 and a Df of 0.0009 at 10 GHz — lower than DiClad 527’s 0.0018 — making it the choice when insertion loss is the dominant constraint. DiClad 527 compensates with significantly better dimensional stability, better registration, and more predictable behavior in volume production. For military radar and commercial base station antenna programs where production yield and consistency matter alongside loss performance, DiClad 527 is often the more practical choice.

2. Can Arlon DiClad 527 be used for multilayer PCB construction?

Yes, but it requires compatible PTFE-based bonding plies rather than standard FR4 prepregs. The bonding materials must be selected to match the CTE and processing temperature requirements of PTFE-based laminates. DiClad 527’s availability down to 0.005″ makes it well suited as thin signal layers in multilayer RF stackups. Consult Rogers/Arlon’s multilayer design guide and confirm your fabricator’s multilayer PTFE process before designing the stackup.

3. Is DiClad 527 a good choice for base station antenna applications?

It is one of the strongest choices in this category. The combination of Df 0.0018 at 10 GHz, water absorption of only 0.03%, UL94-V0 flammability rating, and very low TCDk makes it well suited for outdoor antenna environments where long-term electrical stability under temperature and moisture cycling is required. The excellent dimensional stability also supports multi-circuit panel processing in the high volumes typical of base station antenna production.

4. Does Arlon DiClad 527 require special etching or activation before plating?

Yes. Like all PTFE-based laminates, DiClad 527 requires hole wall activation before electroless copper deposition. The standard approach is sodium naphthalate chemical treatment or plasma etch. This step oxidizes and roughens the PTFE surface to create mechanical adhesion sites for the copper deposit. Without it, the plated through-holes will appear visually acceptable but will fail under thermal cycling due to adhesion failure at the PTFE-copper interface.

5. How do I choose between DiClad 527 and DiClad 522 for my design?

The primary selection criterion is substrate thickness. If your design requires dielectrics thinner than 0.015″ — common in compact multilayer RF stackups — DiClad 527 is the only option, as it is available down to 0.005″. For thicker substrates in the 0.031″ to 0.250″ range, both materials are available, and the choice comes down to panel size availability and your specific Dk requirement. Both share the same electrical properties (Dk 2.40–2.65, Df 0.0018), so there is no electrical performance reason to prefer one over the other when both thickness options exist for your target dimension.

Final Thoughts on Arlon DiClad 527

Arlon DiClad 527 is a mature, well-characterized material that has earned its place in high-performance RF and microwave PCB design by solving a practical problem: how do you get genuinely low-loss PTFE performance in a substrate that behaves predictably in real production environments?

The answer DiClad 527 gives is a deliberately elevated fiberglass-to-PTFE ratio that improves dimensional stability and registration without pushing the dissipation factor beyond what most base station, radar, and phased array applications can tolerate. The near-zero moisture absorption and excellent NASA outgassing performance extend that reliability into outdoor and space-adjacent deployments.

For any new design in the 2.4–2.65 Dk range where production consistency, long-term stability, and PTFE-class loss performance all matter, DiClad 527 deserves to be the first material on your shortlist — not an afterthought. Just make sure your fabricator has genuine PTFE processing capability and can confirm their hole wall activation process before you commit to a stackup.

Arlon DiClad 522 is a PTFE/woven glass laminate with Dk 2.40–2.60 and Df 0.0018 at 10 GHz. Full specs, DiClad 522 vs 527 comparison, fabrication tips, applications & FAQs for RF/microwave PCB design.

When you’re designing RF circuits that demand low loss, tight Dk uniformity, and mechanical behavior closer to FR-4 than typical soft PTFE laminates, Arlon DiClad 522 consistently earns a place on the shortlist. It sits in a practical sweet spot within the DiClad family — higher fiberglass content than the ultra-low-Dk members, which translates into better dimensional stability, more predictable multilayer registration, and a handling experience that doesn’t make your fabrication shop groan.

This guide breaks down everything a working PCB engineer needs to know about Arlon DiClad 522: the material structure, the full specification set, where it performs best, how it compares to close alternatives, and the fabrication realities that determine whether your prototype matches your simulation.

What Is Arlon DiClad 522? Product Family Context

Arlon DiClad 522 belongs to the DiClad series — a family of woven fiberglass/PTFE composite laminates originally developed and manufactured by Arlon Electronic Materials, now part of Rogers Corporation following the 2015 acquisition. The DiClad series covers a range of Dk values by precisely controlling the fiberglass-to-PTFE ratio in the laminate construction.

The DiClad family currently includes four main products: DiClad 880 (Dk 2.17–2.20), DiClad 870 (Dk 2.33), DiClad 522 (Dk 2.40–2.60, tested at 1 MHz), and DiClad 527 (Dk 2.40–2.65, tested at 10 GHz). DiClad 522 and DiClad 527 share the same fundamental construction — a higher fiberglass-to-PTFE ratio than other DiClad members — but differ in how the dielectric constant is characterized and verified. This is a practical distinction that matters when you’re specifying for a microwave application: DiClad 522’s Dk is characterized at 1 MHz, while DiClad 527’s is measured at 10 GHz. For designs where the operating frequency is in the microwave range, DiClad 527’s 10 GHz characterization provides directly relevant data. DiClad 522 remains widely specified and sourced in practice, and the two materials have nearly identical physical construction.

One architectural distinction that sets all DiClad laminates apart from Arlon’s CuClad series is that DiClad materials use a parallel-plied construction — the coated fiberglass plies are aligned in the same direction. This contrasts with CuClad’s cross-plied 90° alternating ply arrangement. The implication is that DiClad 522 does not provide the true XY-plane electrical isotropy that CuClad products offer. For most filter, coupler, power divider, and base station antenna applications, this makes no practical difference. For phased array designs with strict inter-element phase matching requirements, it’s worth factoring in.

For engineers working with an Arlon PCB manufacturer, DiClad 522 is a well-supported, long-established material with broad fabricator familiarity.

Arlon DiClad 522 Material Composition

The properties of DiClad 522 trace directly to its two-component construction.

High Fiberglass-to-PTFE Ratio: The Defining Design Choice

The fundamental design lever in the DiClad series is the ratio of woven fiberglass reinforcement to PTFE matrix. DiClad 522 uses a higher fiberglass-to-PTFE ratio compared to DiClad 880 and DiClad 870. This choice deliberately trades some of the ultra-low-loss performance of pure PTFE composites for mechanical properties that approach conventional substrates.

In practice, this means DiClad 522 is stiffer, dimensionally more stable during lamination and drilling, and exhibits lower CTE in the x and y directions compared to lower-fiberglass-content PTFE laminates. The dimensional stability improvement directly benefits multilayer registration — a persistent challenge with highly compliant PTFE-rich materials.

PTFE Composite Base

Despite its higher glass content, DiClad 522 remains fundamentally PTFE-based. PTFE’s non-polar molecular structure produces inherently low dielectric loss across a wide frequency range. This is the property that makes the DiClad series worth specifying over hydrocarbon or epoxy alternatives in loss-budget-constrained designs. The combination of PTFE’s intrinsic low-loss nature and the woven glass reinforcement’s dimensional stability is what makes DiClad 522 a practical material rather than just a high-performance one.

Woven Fiberglass Reinforcement

The woven glass in DiClad 522 uses PTFE-coated fiberglass cloth, with the plies aligned in the same direction (parallel plied). The consistency and control of this PTFE-coated cloth is a key manufacturing process point — it’s what allows Arlon/Rogers to produce DiClad 522 with better Dk uniformity than comparable non-woven fiberglass reinforced PTFE laminates. Dk uniformity matters enormously in filter and coupler designs, where the resonant frequency and coupling coefficient of each circuit element depend directly on the local dielectric constant the element experiences.

Arlon DiClad 522 Full Specifications

Here is a comprehensive view of DiClad 522’s key properties, drawn from the Arlon Microwave Materials Guide and published datasheet data.

Electrical Properties

Property	Value	Test Condition
Dielectric Constant (Dk)	2.40–2.60	1 MHz
Dissipation Factor (Df)	0.0018	10 GHz
Thermal Coefficient of Dk	–153 ppm/°C	—
Dk Stability vs. Frequency	Stable, characterization curve available	MHz to >10 GHz

Thermal and Environmental Properties

Property	Value	Test Method
Water Absorption	0.03%	ASTM D792 / IPC
Thermal Conductivity	0.254 W/(m·K)	—
NASA Outgassing – Total Mass Loss	0.02%	NASA SP-R-0022A
NASA Outgassing – CVCM	0.00%	NASA SP-R-0022A
Flammability Rating	UL94 V-0	UL

Mechanical and Physical Properties

Property	Value
Density	2.31 g/cc
CTE – X axis	14 ppm/°C
CTE – Y axis	21 ppm/°C
CTE – Z axis	173 ppm/°C
Typical Peel Strength	14 lbs
Tensile Modulus	~706 kpsi

Available Configurations

Parameter	Options
Dielectric Constant Range	2.40–2.60 (selectable in increments)
Standard Copper Weights	½ oz, 1 oz, 2 oz electrodeposited
Alternative Copper	Rolled copper foil (on request)
Metal-Backed Options	Aluminum, brass, or copper ground plane
Panel Sizes	Up to 36″ × 48″ (parallel plied)

Translating the Key Numbers to Real Design Impact

Dissipation factor of 0.0018 at 10 GHz is roughly half that of RO4350B (0.0037) and nearly one order of magnitude better than FR-4 (0.020+). For a base station antenna feed network with 15 inches of transmission line at 5.8 GHz, that difference in Df translates to meaningfully lower insertion loss — directly affecting antenna gain and system noise figure in receive paths.

Thermal coefficient of Dk at –153 ppm/°C is a specification that many engineers overlook until it bites them in production. A negative TCDk means the dielectric constant decreases as temperature rises. For a filter centered at 5.8 GHz, a significant operating temperature swing will shift the resonant frequency proportionally to the Dk change. This needs to be budgeted in the design, especially for outdoor infrastructure equipment cycling between –40°C and +85°C. DiClad 522 has better TCDk than pure PTFE-dominated laminates, but it’s a parameter that deserves simulation attention in temperature-sensitive designs.

X-axis CTE of 14 ppm/°C and Y-axis CTE of 21 ppm/°C are notably lower than typical pure PTFE-rich laminates, which is the direct result of the higher fiberglass content. Copper’s CTE is approximately 17 ppm/°C. The x-axis CTE essentially matches copper, which is why DiClad 522 shows better in-plane dimensional stability than lower-glass alternatives. The anisotropy between X (14 ppm/°C) and Y (21 ppm/°C) reflects the parallel-plied construction — the glass fabric’s warp and fill directions have different reinforcement densities.

Z-axis CTE of 173 ppm/°C is substantially higher than the x and y axes — this is typical for PTFE-based laminates and requires attention in through-hole design. Compared to FR-4’s z-axis CTE of 60–80 ppm/°C, DiClad 522 imposes more stress on plated through-hole barrel walls during thermal cycling. Good PTH design practices (conservative aspect ratios, adequate annular rings, proper through-hole activation before plating) are essential.

Water absorption of 0.03% is excellent for any PCB material. For RF circuits installed in outdoor base station cabinets or military equipment exposed to humidity cycling, moisture uptake is a direct threat to impedance stability. DiClad 522’s 0.03% absorption effectively removes moisture as a variable in deployed system performance.

Arlon DiClad 522 vs. Competing Materials

DiClad 522 vs. DiClad 527

Parameter	DiClad 522	DiClad 527
Dk Range	2.40–2.60	2.40–2.65
Dk Test Frequency	1 MHz	10 GHz
Construction	Parallel plied	Parallel plied
Dimensional Stability	Good	Better
Typical Use Case	Filter/coupler design	Microwave circuits, multilayer

DiClad 527 is specified when the application is explicitly in the microwave range and you want Dk data that corresponds directly to your operating frequency. Its slightly higher fiberglass content (reflected in the extended Dk range to 2.65) gives it better dimensional stability and registration in multilayer lamination. For single and double-sided filter designs where Dk at 1 MHz is an adequate specification anchor, DiClad 522 is an equivalent and widely available option.

DiClad 522 vs. Rogers RO4350B

Parameter	Arlon DiClad 522	Rogers RO4350B
Dk (10 GHz)	2.40–2.60	3.48
Df (10 GHz)	0.0018	0.0037
CTE – Z axis	173 ppm/°C	32 ppm/°C
Processing	PTFE-specialized	FR-4 compatible
Moisture Absorption	0.03%	0.06%
Peel Strength	14 lbs	Higher (thermoset adhesion)

RO4350B is the default choice for cost-driven commercial RF designs because it processes like FR-4 — no PTFE-specific through-hole activation, no specialized lamination procedures. It’s also a hydrocarbon/ceramic thermoset, meaning the z-axis CTE (32 ppm/°C) is far more favorable for PTH reliability than DiClad 522’s 173 ppm/°C. For production volumes where fabrication cost and yield matter, RO4350B’s processing advantages are real. DiClad 522 wins on loss (roughly 2× lower Df) and moisture performance, but these advantages only justify the added fabrication complexity where the design genuinely needs them.

DiClad 522 vs. Arlon DiClad 880 (Dk 2.17–2.20)

Parameter	Arlon DiClad 522	Arlon DiClad 880
Dk (10 GHz)	2.40–2.60	2.17–2.20
Df (10 GHz)	0.0018	~0.0009
Glass Content	Higher	Lower
Dimensional Stability	Better	Softer, more compliant
Circuit Size at Dk	Smaller than DiClad 880	Larger circuits at same freq.

DiClad 880 offers lower Dk and lower Df — the best electrical performance in the DiClad family. But the lower glass content makes it softer, more difficult to handle in a production fab environment, and more prone to dimensional variation during multilayer lamination. DiClad 522’s higher glass content is a genuine practical advantage when designing multilayer circuits or working in a volume production context. For designs where trace widths and circuit size are constrained, DiClad 522’s higher Dk allows somewhat more compact geometries than DiClad 880 at the same operating frequency.

DiClad 522 vs. Arlon CuClad 250

Parameter	Arlon DiClad 522	Arlon CuClad 250
Dk Range	2.40–2.60	2.40–2.60
Df (X-band)	0.0018	0.0018
Construction	Parallel plied	Cross-plied
XY Isotropy	No	Yes
Best For	Filters, couplers, power dividers	Phased arrays, isotropic designs

DiClad 522 and CuClad 250 cover essentially the same Dk and Df territory. The key differentiation is construction: CuClad 250’s cross-plied layers provide verified XY-plane electrical and mechanical isotropy. For designs where circuit orientation relative to the fiber direction is a concern — particularly phased array antennas — CuClad 250’s isotropy is the right choice. For most planar filter, coupler, and combiner designs, the orientation doesn’t matter and DiClad 522 is a straightforward, equivalent option.

Application Areas Where Arlon DiClad 522 Delivers

Military Radar Feed Networks

Radar feed networks route transmit and receive signals between the transceiver and the antenna elements. They require low insertion loss (to maximize effective radiated power and receiver sensitivity), predictable impedance (to minimize reflections that degrade radar resolution), and stable performance over military temperature ranges. DiClad 522’s combination of low Df, good Dk uniformity, and UL94 V-0 flammability rating suits these requirements. The NASA-compliant outgassing data (Total Mass Loss 0.02%, CVCM 0.00%) also makes it viable for airborne applications where outgassing can contaminate optics and sensitive sensors.

Commercial Phased Array Networks

Large commercial phased arrays — for 5G base stations, point-to-multipoint links, and satellite terminal antennas — need low-loss feed networks connecting multiple radiating elements. DiClad 522’s stable Dk across frequency keeps impedance consistent as the operating band changes, and the 0.0018 Df at 10 GHz provides acceptable insertion loss performance for commercial system budgets. At frequencies below 10 GHz where most commercial phased arrays operate, this material is well-matched to the application.

Low Loss Base Station Antennas

Base station antenna companies have been using Arlon DiClad materials for decades for this reason: the Dk range of 2.40–2.60 allows reasonably compact transmission line and coupler geometries, the low Df keeps insertion loss within system budgets at 1.7–5.9 GHz, and the long-term outdoor environmental performance — aided by 0.03% moisture absorption — supports 10–20 year service life requirements. DiClad 522 is explicitly named by Arlon as a target application, and it has the track record to support this use.

Filters, Couplers, and Power Dividers

These passive microwave components live and die by Dk uniformity — a shift in local dielectric constant shifts the electrical length of resonators, changes coupling coefficients, and moves passband edges. DiClad 522’s better-than-nonwoven Dk uniformity, produced by the precise PTFE-coated woven glass cloth, directly supports predictable filter and coupler performance. For Ku-band and X-band bandpass filters targeting precise passbands with low group delay ripple, DiClad 522’s uniformity makes the design-to-hardware correlation more reliable.

Missile Guidance Systems and Digital Radio Antennas

DiClad 522 is explicitly listed in Arlon’s application guidance for missile guidance systems. The combination of NASA-compliant outgassing, low loss, excellent chemical resistance, and dimensional stability under vibration all contribute. Digital radio antennas — whether for military UHF/VHF communications or commercial microwave backhaul — benefit from the same low-loss, low-moisture-absorption properties.

Fabrication Guidelines for Arlon DiClad 522

DiClad 522 requires PTFE-appropriate fabrication processes. Its higher glass content relative to other DiClad members makes it somewhat easier to handle than ultra-PTFE-rich laminates, but PTFE-specific steps are still mandatory.

Through-Hole Surface Activation

PTFE is chemically inert — excellent for dielectric performance, terrible for copper adhesion without surface treatment. Drilled holes through DiClad 522 must be activated before electroless copper deposition. Accepted methods are sodium etch (chemical activation using sodium/naphthalene) or plasma etch (oxygen plasma). Shops without one of these processes in place should not be processing DiClad 522. Failure to activate leads to zero copper adhesion in the barrel, producing open PTHs or intermittent connections that may not fail immediately but will fail in thermal cycling.

Drilling Parameters

DiClad 522’s higher fiberglass content makes it harder and more abrasive than lower-glass PTFE laminates. Use drill bit specifications appropriate for glass-PTFE composites, including appropriate entry and backup materials. Expect shorter drill bit life than for pure PTFE laminates. Adjust feed rates to minimize PTFE smear on hole walls, which would reduce the effectiveness of subsequent sodium or plasma etch activation.

Lamination for Multilayer Designs

For multilayer DiClad 522 designs, use compatible PTFE bonding materials — Rogers 2929 or equivalent. Standard FR-4 prepregs are not appropriate for bonding PTFE-based core layers. The higher glass content in DiClad 522 compared to DiClad 880 or CuClad 217 provides better dimensional predictability during lamination, but PTFE-specific lamination profiles (temperature, pressure, and vacuum schedule) must still be followed. Pre-bake the laminate cores to remove moisture before lamination.

Copper Foil and Surface Finish

DiClad 522 is supplied with ½ oz, 1 oz, or 2 oz electrodeposited copper as standard; rolled copper is available on request. For designs at 5.8 GHz and above, rolled or smooth copper foil reduces conductor loss compared to standard electrodeposited copper. At these frequencies, the skin depth becomes comparable to surface roughness. ENIG and immersion silver are the recommended surface finishes. HASL is generally not appropriate for high-frequency PTFE-based boards due to surface irregularity.

Metal-Backed Configurations

DiClad 522 is available bonded to aluminum, brass, or copper ground plane plates. These metal-backed configurations provide integral heat sinking and mechanical rigidity, making them valuable for power amplifier substrates and antenna panels where thermal management and structural stiffness are required alongside the RF performance.

Material Selection Decision Framework

Design Requirement	DiClad 522 Fit
Low loss at 1–18 GHz	✅ Excellent
Low moisture / outdoor environment	✅ Excellent
Tight Dk uniformity for filters	✅ Excellent
UL94 V-0 compliance needed	✅ Excellent
NASA outgassing compliance needed	✅ Excellent
PTFE-capable fabricator available	Required
FR-4 processing preferred	⚠️ Consider RO4350B
XY-plane isotropy needed (phased arrays)	⚠️ Consider CuClad 250
Absolute lowest loss required	⚠️ Consider DiClad 880
Above 20 GHz operation	⚠️ Evaluate mmWave-specific materials

Useful Resources for Arlon DiClad 522 Design and Procurement

• Rogers DiClad Series Product Page — rogerscorp.com/diclad-series-laminates — Current product information, Laminate Properties Tool, and Dk/Df vs. frequency curves
• Rogers DiClad Datasheet (PDF) — Available from Rogers’ website and authorized distributors; includes DiClad 522 and 527 physical and electrical data
• Arlon DiClad/CuClad/IsoClad Fabrication Guidelines (PDF) — Available via RF Global Net and Rogers’ technical library; essential for fabricators new to DiClad processing
• Matweb DiClad 522/527 Database Entry — matweb.com — Property data for mechanical modeling and thermal simulation
• Arlon Microwave Materials Guide (PDF) — Full Arlon laminate comparison table including DiClad 522 data; available from Rogers’ authorized distributors
• Rogers Laminate Properties Tool — Interactive tool for comparing DiClad 522 against other Rogers/Arlon laminates on specific properties
• Saturn PCB Toolkit — Free PCB impedance calculator with PTFE laminate support; useful for microstrip and stripline trace width calculations on DiClad 522

Frequently Asked Questions About Arlon DiClad 522

Q1: What is the practical difference between DiClad 522 and DiClad 527, and which should I specify?

Both materials share the same high-fiberglass PTFE composite construction and Dk range (2.40–2.65), but differ in how Dk is characterized: DiClad 522 at 1 MHz, DiClad 527 at 10 GHz. For microwave applications from 1–18 GHz, DiClad 527’s 10 GHz Dk data is more directly relevant to your design. DiClad 527 also has slightly better dimensional stability. In practice, many engineers and fabricators treat these as interchangeable for design purposes. If your application is above 1 GHz, specify DiClad 527 for more accurate datasheet-to-simulation correlation; use DiClad 522 when it’s the available stock option and you verify Dk at your operating frequency.

Q2: Can I use DiClad 522 in a hybrid stackup with RO4350B or FR-4 layers?

Yes, hybrid stackups are commonly used to reduce cost by confining DiClad 522 to the RF-critical signal layers while using less expensive materials for power and ground planes or digital signal layers. The key challenge is managing CTE mismatch between PTFE-based and epoxy/hydrocarbon layers. Use a PTFE-compatible bonding film at all material interfaces, and verify your hybrid stackup design with the fabricator before production. Perform thermal cycling qualification testing — especially if the board will see wide temperature excursions in service. A fabricator with prior hybrid stackup experience is important here.

Q3: Why is DiClad 522 preferred over CuClad 250 for filter and combiner applications?

For planar filter and combiner designs, the dielectric constant uniformity that DiClad 522 offers is the primary driver — both materials cover similar Dk and Df territory. CuClad 250 adds cross-plied XY isotropy, which is valuable for phased array applications but irrelevant for most filter and combiner designs where circuit orientation is fixed. DiClad 522’s parallel-plied construction is simpler to produce and can offer slightly better Dk uniformity in specific configurations. Both are valid choices; for filters and combiners, the choice often comes down to which material your preferred fabricator holds in stock.

Q4: Does DiClad 522 need any special handling before fabrication?

Yes. Like all PTFE-based laminates, DiClad 522 should be pre-baked before lamination and drilling to remove absorbed moisture (typically 150–180°C for 1–2 hours). The material should be handled with clean gloves to avoid surface contamination. Store in a dry environment when not being processed. The higher glass content in DiClad 522 makes it mechanically stiffer than lower-glass PTFE laminates like DiClad 880, which reduces but does not eliminate the risk of panel warpage during handling. Standard PTFE laminate precautions apply throughout the fabrication process.

Q5: Is Arlon DiClad 522 suitable for commercial 5G base station antenna designs at 3.5 GHz?

Absolutely — this is one of the application areas where DiClad 522 delivers excellent value. At 3.5 GHz, the loss advantage over RO4350B (Df 0.0018 vs. 0.0037) is meaningful for long signal path feed networks, and the moisture absorption of 0.03% versus RO4350B’s 0.06% helps maintain consistent antenna performance over years of outdoor humidity cycling. The material’s track record in base station antenna applications is long and well-established. Work with a fabricator experienced in PTFE materials, specify ENIG or immersion silver surface finish, and you’ll find DiClad 522’s performance-to-cost ratio attractive for commercial antenna production volumes.

Summary: Where Arlon DiClad 522 Belongs in Your Material Selection

Arlon DiClad 522 delivers a specific and well-proven combination of properties: low RF loss (Df 0.0018 at 10 GHz), excellent Dk uniformity across frequency, outstanding moisture resistance (0.03% absorption), NASA-compliant outgassing, and mechanical properties that approach conventional substrates — all in a woven glass PTFE composite with decades of field-proven reliability.

It’s not the right material for every application. If you need FR-4-style processing without PTFE-specific fabrication steps, RO4350B belongs on your shortlist. If you need the absolute lowest loss and don’t mind a softer, more compliant material, look at DiClad 880 or CuClad 217. If XY-plane isotropy is non-negotiable for a phased array, use CuClad 250 instead.

But for military radar feed networks, base station antenna panels, microwave filters and couplers, missile guidance electronics, and any design where low loss, Dk uniformity, and long-term moisture stability matter — Arlon DiClad 522 has earned its reputation as a dependable, well-characterized workhorse material that bridges the gap between the extreme performance of pure PTFE composites and the manufacturing convenience of standard substrates.

Arlon CuClad 6700 PTFE bondply: full guide to electrical properties (Dk 2.35, Df 0.0025), multilayer PCB lamination parameters, NASA/ESA space compliance, and how it compares to Rogers 2929 and CuClad 6250. Written for RF and microwave PCB engineers.

If you’ve spent any time designing high-frequency multilayer PCBs, you already know that the bonding material sitting between your substrate layers is just as critical as the laminate itself. Get it wrong, and you’ll spend weeks chasing impedance anomalies or delamination failures in the field. Get it right, and your stripline structure will hold its electrical properties through temperature swings, pressure cycles, and the general abuse of real-world deployment.

Arlon CuClad 6700 is one of those materials that, once you understand it properly, becomes a trusted tool in the RF engineer’s stack. This guide covers everything from the chemistry and electrical specs through to practical lamination parameters and multilayer stackup guidance — written from the perspective of someone who actually has to build with this stuff.

What Is Arlon CuClad 6700?

Chemistry and Material Composition

CuClad 6700 is a chloro-trifluoroethylene (CTFE) thermoplastic co-polymer bonding film originally developed under Arlon’s microwave materials division, now marketed under Rogers Corporation following their acquisition of Arlon’s electronic materials business. It is specifically engineered for bonding PTFE-based substrates in microwave stripline packages and other multilayer PCB circuits.

The CTFE chemistry is an important distinction here. Unlike standard epoxy-based prepregs commonly found in FR-4 multilayer work, CuClad 6700 belongs to the fluoropolymer family — giving it a dielectric profile that closely tracks the PTFE laminates it’s designed to bond. This means your electrical stack stays consistent, without the property mismatch you’d introduce by using a conventional prepreg between low-Dk PTFE substrate layers.

Where It Fits in the CuClad Family

The CuClad product line covers both laminates (CuClad 217, CuClad 233, CuClad 250) and bonding films (CuClad 6250 and CuClad 6700). The bonding films sit in the mid-range of the CuClad and DiClad laminate series’ dielectric constant spread, which makes them a natural electrical match for the most widely used substrates in the family.

CuClad 6700 is the higher-temperature variant of the two bonding films. Its sister product, CuClad 6250, uses an EAA thermoplastic co-polymer chemistry and processes at significantly lower temperatures. Choosing between them usually comes down to your lamination press capabilities and the thermal requirements of your specific multilayer build.

Arlon CuClad 6700 Key Electrical Properties

For RF and microwave engineers, electrical properties aren’t just numbers to put in a report — they directly govern how your transmission lines behave at frequency. Here’s what matters:

Dielectric Constant (Dk)

Property	Value	Test Condition
Dielectric Constant (Dk)	2.35	10 GHz
Loss Tangent (Df)	0.0025	10 GHz
Dielectric Constant (Dk) — Alt. Source	2.30	10 GHz

The Dk of 2.35 falls comfortably in the mid-range of the CuClad laminate system. This is intentional. When you’re building a multilayer with CuClad 217 (Dk ~2.17) or CuClad 233 (Dk ~2.33) as your core laminate, the bonding film’s dielectric constant needs to be close enough that it doesn’t create localized impedance discontinuities at the bond interfaces.

The small variance you’ll see between datasheets (2.30 vs. 2.35) is a function of measurement methodology and material lot variation. For design work, using 2.35 as your design value and confirming with your fabricator’s measured data is the prudent approach.

Loss Tangent

A loss tangent of 0.0025 at 10 GHz is excellent for a bonding film. For comparison, standard FR-4 prepreg runs anywhere from 0.015 to 0.025 — roughly an order of magnitude worse. If you’re designing above a few GHz, this difference is the reason why you’d specify CuClad 6700 rather than reaching for whatever bonding material is cheapest. The lower insertion loss translates directly to better system sensitivity and reduced thermal load on amplifier stages.

Physical and Thermal Properties

Thickness Options

CuClad 6700 is available in two standard thicknesses:

Thickness (Imperial)	Thickness (Metric)
0.0015 in	0.038 mm
0.003 in	0.076 mm

The choice between these two depends on how much copper trace height you need to encapsulate. A general rule of thumb: you need enough bondply thickness to fully encapsulate the etched copper traces plus provide the required additional dielectric between layers. For finer trace geometries, the 0.0015″ option works well. For heavier copper weights or designs with more substantial fill requirements, step up to 0.003″.

Thermal and Physical Properties Summary

Property	Value
Thermoplastic Melt Temperature	397°F (203°C)
Maximum Process Temperature	475°F (246°C)
Water Absorption	Very low
Outgassing	Low
Form Factor	24″ (610mm) roll and sheet
RoHS Compliant	Yes
NASA/ESA Space Compliant	Yes

The melt temperature of 397°F (203°C) is high enough to provide stability in soldering operations yet still allows a workable press window. The low outgassing value is particularly relevant for satellite and space programs — this is one of the reasons CuClad 6700 carries NASA/ESA compliance certification for space and satellite applications.

Arlon CuClad 6700 Key Benefits for PCB Engineers

Intrinsic Flame Resistance

The CTFE fluoropolymer chemistry provides inherent flame resistance without the need for halogen-based flame retardant additives. This is a meaningful advantage in applications where UL94 V-0 performance is required without compromising electrical properties — which is exactly what happens when you load up a resin system with brominated flame retardants.

Excellent Match to Low-Dk PTFE Laminate Systems

This is the core value proposition of CuClad 6700 in a multilayer design context. When you’re building a stripline board using CuClad 217 or CuClad 233 as your signal layers, you need a bondply whose dielectric constant doesn’t create impedance bumps at each layer interface. The 2.35 Dk of CuClad 6700 sits close enough to the CuClad laminate range that your stack behaves as a near-homogeneous dielectric medium at microwave frequencies.

Shorter Press Cycle Than Thermoset Prepregs

Compared to high-frequency thermoset prepregs, CuClad 6700 offers a shorter overall lamination cycle. The thermoplastic resin’s hold time during pressing is shorter, which improves throughput on the press and reduces overall manufacturing cost. For high-volume production runs, this is a meaningful operational advantage.

Reworkability — A Thermoplastic Advantage

One benefit that often gets overlooked in specification sheets is that CuClad 6700’s thermoplastic nature means it can be reheated to remelt and reflow the bonding film. This is a significant advantage over thermoset bondplies, which cure irreversibly. In a multilayer assembly that requires rework or correction before final cure, the ability to reverse the bond is extremely valuable — particularly in prototype or low-volume defense and aerospace builds where the cost of scrapping a partially completed stack is substantial.

Space and Satellite Qualification

Compliance with NASA/ESA guidelines for satellite and space applications opens up CuClad 6700 for some of the most demanding programs in the industry. Low outgassing is an absolute requirement in space environments — materials that offgas in a vacuum can deposit contamination on optical surfaces, solar cells, or sensitive sensors. CuClad 6700’s low outgassing profile satisfies these stringent requirements.

Multilayer PCB Lamination Process Guide

Getting CuClad 6700 lamination right is not complicated, but it is process-sensitive. Unlike FR-4 prepreg which tolerates a fairly wide process window, fluoropolymer bondplies reward careful attention to temperature uniformity and cool-down rate.

Surface Preparation

PTFE surfaces are notoriously difficult to bond. Before lamination, copper surfaces should be properly prepared — options include:

• Chemical etching (preferred method for PTFE surfaces)
• Gas plasma treatment — effective for both through-hole preparation and multilayer lamination adhesion promotion
• Sodium naphthalene etching (FluoroEtch or Tetra-Etch type treatments) to micro-roughen the PTFE surface

Avoid mechanical scrubbing of PTFE laminate surfaces after etching. The copper foil creates a dendrite pattern in the PTFE during lamination that is essential for subsequent bond quality — mechanical abrasion can destroy this microstructure and compromise interlayer adhesion.

Handling should always be done wearing clean gloves to prevent transfer of skin oils to bonding surfaces. Once prepared, panels should be stored in a clean, dry environment and laminated within 24 hours of surface treatment.

CuClad 6700 Lamination Parameters

Process Step	Parameter
Suggested Set Temperature	450°F (232°C)
Minimum Bond Temperature	400°F (204°C)
Maximum Process Temperature	475°F (246°C)
Hold Time at Temperature	15 minutes minimum
Lamination Pressure	~100 psi (200 psi for complex fill)
Maximum Cool-down Rate	10°F/min
Removal Temperature	Below 200°F (93°C)

A few process notes worth emphasizing from experience with PTFE multilayer lamination:

Use a thermocouple at the bond line. Don’t rely solely on press platen temperature. Place a thermocouple at the edge of the bond line (outside the working area) to confirm actual interface temperature. PTFE laminates are thermally insulating — the temperature gradient between the press platen and the center of the stack can be significant, especially on thicker builds.

The 15-minute hold is non-negotiable. Insufficient time at temperature results in a failed or spotty bond. This is one of the most common causes of field delamination in PTFE multilayer boards — the press cycle was slightly short, the bond looked fine visually, but adhesion was marginal.

Control your cool-down rate. Forced cooling faster than 10°F/min without adequate pressure will cause warpage or partial debonding. If you’re transferring to a cooling press, make sure it’s still hot when you transfer — never let the stack sit on a cold surface. Cool-down pressure should match the hot-press pressure.

Layup Procedure

1. Lay the CuClad 6700 bonding film between the layers to be laminated, ensuring sufficient film area to encapsulate the full copper trace and pattern height
2. Use adequate film thickness to provide the required dielectric spacing after flow
3. Place thermocouple at bond line edge
4. Preheat press to ~450°F
5. Apply ~100 psi pressure; increase to 200 psi for complex trace fills
6. Hold at bond temperature for minimum 15 minutes
7. Cool under pressure at ≤10°F/min to below 200°F before panel removal

Availability and Format

CuClad 6700 is available in both roll form and sheet form at 24″ (610mm) width. There are no shelf-life limitations when stored in original sealed packaging at temperatures below 25°C (77°F) and relative humidity below 70%. Film rolls should be stored on edge (upright) or suspended by roll cores to prevent flat spots and creasing from the weight of the roll.

Typical Applications for CuClad 6700

Microwave Stripline Circuitry

Stripline is the primary application for CuClad 6700. A stripline structure buries the signal conductor between two ground planes — which means you’re always dealing with a bonded multilayer structure. The dielectric properties of your bondply directly contribute to your controlled impedance. CuClad 6700’s Dk closely tracks the surrounding PTFE laminate, which simplifies impedance modeling and improves predictability of the finished product.

Hybrid Multilayer Constructions

In hybrid multilayer designs — where PTFE-based RF layers are combined with other substrate types for digital or power supply layers — CuClad 6700 facilitates the RF portion of the stack. Sequential lamination techniques using films with different melt temperatures allow complex hybrid constructions to be built reliably.

Heat Sink and Thermal Management Integration

CuClad 6700 can bond PCBs to heavy plate heat sinks, metal housings, and RF module enclosures. This is useful in power amplifier and high-power RF module applications where the circuit board needs to be thermally coupled to a chassis or heatsink structure.

Satellite and Space Electronics

NASA/ESA compliance makes CuClad 6700 suitable for space hardware. Applications include antenna feed networks, satellite transponder circuitry, phased array feed structures, and communications system boards where outgassing limits are strictly enforced.

Wireless Infrastructure

CuClad 6700 appears in Rogers’ own product selector guide as a recommended bonding material for wireless infrastructure applications — including base station antennas, backhaul radios, and power amplifier boards. The combination of low loss, controlled Dk, and process reliability makes it well-suited to the high volumes and tightened electrical tolerances of telecom hardware.

CuClad 6700 vs. Other Rogers Bonding Films

When selecting a bondply for a high-frequency multilayer PCB, CuClad 6700 is one of several options in the Rogers portfolio. Understanding how it compares helps narrow down the right choice for your specific build.

Bonding Material	Chemistry	Dk (10 GHz)	Df (10 GHz)	Melt Temp	Key Advantage
CuClad 6700	CTFE Thermoplastic	2.35	0.0025	397°F (203°C)	PTFE system match, space qualified
CuClad 6250	EAA Thermoplastic	2.32	~0.002	213°F (101°C)	Low temperature process, foam substrates
Rogers 2929 Bondply	Thermoset	2.94	0.003	Thermoset	Controlled flow, multiple lamination cycles
Rogers 3001 Bonding Film	Chlorofluoropolymer	~2.3	Low	~265°F	Very low Dk/Df, sequential lamination
CLTE-P	Thermoplastic	2.98	0.0023	265°C	Sequential lamination, low CTE

Choose CuClad 6700 when your core laminates are PTFE-based (CuClad, DiClad, RT/duroid), you need space qualification, or your process requires the reworkability that thermoplastic chemistry enables.

Choose CuClad 6250 when your lamination press has lower temperature capability, or when bonding pressure-sensitive substrates like dielectric foam materials that can’t tolerate 450°F processing.

Choose Rogers 2929 when you’re working in an environment that performs multiple lamination cycles (sequential lamination), need controlled resin flow for complex geometries, or your Dk requirements can tolerate the higher ~2.94 value.

Design Considerations for Engineers

Impedance Modeling With CuClad 6700

When building a controlled impedance stripline structure using CuClad laminate with CuClad 6700 bondply, treat the bond film as an additional dielectric layer in your stack calculation. The 2.35 Dk value should be used in your impedance solver — most field solvers handle mixed dielectric stacks well, but verify that your solver handles thin bondply layers correctly. Some simplified calculators assume homogeneous dielectric, which can introduce errors when bonding film layers are comparable in thickness to trace height.

Copper Surface Finish Compatibility

CuClad 6700 bonds to the copper cladding on standard electro-deposited (ED) and rolled-annealed (RA) copper foils. For optimal adhesion to PTFE surfaces, chemical surface treatment (sodium-based etchants or plasma treatment) is required. If you’re designing a board that will use immersion gold or other surface finishes, confirm with your fab that the CuClad 6700 lamination is performed before any post-lamination plating operations that might affect adhesion chemistry.

Via and Through-Hole Considerations

Plasma treatment has been shown to promote adhesion in plated through-hole regions as well as at the lamination interface. For PTH reliability in a PTFE multilayer stack, confirm that your fabricator’s PTH preparation process is compatible with PTFE substrates — standard desmear processes designed for FR-4 may not be appropriate.

For Arlon PCB fabrication, working with a fabricator experienced in fluoropolymer materials is strongly recommended. The process sensitivities of PTFE-based multilayers are meaningful, and fabricators without experience often underestimate the differences from standard FR-4 processing.

Useful Resources for Engineers

Resource	Description	Link
Rogers Corporation – CuClad 6700 Product Page	Official product page with downloads	rogerscorp.com
CuClad 6250 & 6700 Data Sheet (PDF)	Official Rogers datasheet with full lamination guide	Download PDF
Rogers Bonding Material Properties Tool	Interactive selector comparing all Rogers bondplies	tools.rogerscorp.com
Rogers High Frequency Product Selector Guide (PDF)	Full portfolio overview across all Rogers HF materials	Available on Rogers downloads page
Rogers Technology Support Hub	Technical papers, white papers, calculators for AES materials	rogerstechub.com
MatWeb – CuClad 6700 Entry	Third-party material property database	matweb.com
IPC-TM-650 Test Methods	Standard test methods referenced in Rogers datasheets	ipc.org

Frequently Asked Questions About Arlon CuClad 6700

1. Can CuClad 6700 be used with non-PTFE laminates?

Yes — while CuClad 6700 is specifically optimized for bonding PTFE-based substrates, it can also be used to bond other structural and electrical components to the dielectric. That said, its primary value lies in its dielectric compatibility with the CuClad and DiClad laminate families. If you’re bonding to non-PTFE substrates, evaluate whether the 450°F process temperature is compatible with those materials before committing to this bondply.

2. What happens if the lamination temperature is too low?

If the bond interface doesn’t reach the minimum 400°F (204°C) threshold, the thermoplastic film will not fully reflow and wet the mating surfaces. The result is a failed or spotty bond that may pass visual inspection but will fail under peel testing or thermal cycling. Always use a thermocouple at the bond line — not just the press platen — to confirm interface temperature.

3. Is CuClad 6700 compatible with lead-free soldering processes?

Yes. CuClad 6700 is RoHS compliant and its thermoplastic melt temperature of 397°F (203°C) provides adequate headroom above typical lead-free solder reflow profiles (typically 250–260°C peak). However, confirm the full thermal profile of your reflow process against the material’s service temperature limit. Repeated reflow cycles should be evaluated against potential bond fatigue.

4. What is the shelf life of CuClad 6700?

There are no shelf-life limitations when CuClad 6700 is stored in its original sealed packaging at temperatures not exceeding 25°C (77°F) and relative humidity below 70%. Proper storage orientation (rolls stored on edge or suspended from roll cores) prevents physical deformation of the film.

5. How does CuClad 6700 compare to Rogers 2929 Bondply for general multilayer RF applications?

The key differences are chemistry type and dielectric constant. CuClad 6700 is a thermoplastic with Dk of 2.35 — ideally matched to PTFE laminate systems. Rogers 2929 is a thermoset bondply with Dk of ~2.94 — better suited to hydrocarbon and ceramic-loaded systems like the RO4000 series. If your core laminates are CuClad or DiClad PTFE materials, CuClad 6700 will give you better dielectric continuity through the stack. If you’re in the RO4000 family, 2929 is the natural pairing. The other practical distinction is that CuClad 6700 can be reheated and rebonded (thermoplastic), while 2929 cures irreversibly (thermoset).

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Summary

Arlon CuClad 6700 is a purpose-built PTFE bondply that belongs in any serious RF multilayer PCB design toolbox. Its CTFE thermoplastic chemistry delivers a dielectric constant of 2.35 and a loss tangent of 0.0025 at 10 GHz — closely matched to the CuClad laminate family it’s designed to bond. The thermoplastic nature means shorter press cycles, reworkable bonds, and the low outgassing profile needed for space-qualified hardware.

For the fabricator, the 450°F lamination window requires a capable press and careful thermocouple monitoring, but the process is well-documented and repeatable once characterized. For the designer, the dielectric match simplifies stackup modeling and gives confidence that the finished board will behave as simulated.

Whether you’re building a satellite transponder, a 5G base station power amplifier board, or a precision microwave filter, CuClad 6700 earns its place between the substrate layers of your high-frequency multilayer stack.

Arlon CuClad 250 is a cross-plied woven PTFE/fiberglass laminate with Dk 2.40–2.60 and low loss for military radar, ECM, and microwave filter PCBs. Complete guide to CuClad 250 properties, GT vs GX vs LX grades, fabrication tips, and comparison with CuClad 217 and Rogers RT/duroid 5880.

There’s a reason Arlon CuClad 250 keeps showing up on defense radar BOMs, ECM system stackups, and filter board specs that have been refreshed multiple times over the decades. It isn’t the flashiest microwave laminate on the market — it won’t win a Df shootout against the latest ceramic/PTFE composite — but it hits a combination of mechanical robustness, dimensional stability, in-plane electrical isotropy, and low loss that keeps earning its spot when designers have to balance fabrication practicality with genuine RF performance.

This guide gives you the complete picture: what CuClad 250 actually is, what its properties mean in practice, how it compares to the rest of the CuClad family and to competing materials, and where it genuinely earns its place in a design.

What Is Arlon CuClad 250?

Arlon CuClad 250 is a woven fiberglass/PTFE composite laminate engineered for use as a microwave printed circuit board substrate. Within the CuClad product family, it occupies the high-fiberglass-ratio end of the spectrum — using a higher fiberglass/PTFE ratio than CuClad 217 or CuClad 233 to provide mechanical properties approaching those of conventional substrates.

That higher glass loading has a direct effect on Dk. Where CuClad 217 sits at Er = 2.17–2.20, CuClad 250 ranges from Er = 2.40 to 2.60 depending on the specific grade and thickness specified. The increase in Dk relative to the lower-glass CuClad grades is the direct result of more fiberglass in the matrix — glass has a higher dielectric constant than PTFE, so more glass means higher Dk.

What you gain from that tradeoff is a laminate that behaves much more like FR-4 from a mechanical standpoint — better dimensional stability, lower thermal expansion in all directions, and a substrate that handles more like a conventional epoxy laminate during fabrication. For shops that routinely build FR-4 multilayers but occasionally take on microwave work, that processability difference matters enormously.

The Cross-Ply Construction That Sets CuClad Apart

If there’s one technical differentiator that genuinely sets the CuClad family apart from competing woven PTFE laminates, it’s the cross-plied construction. CuClad laminates are crossplied — alternating layers of coated fiberglass plies are oriented 90° to each other. This provides true electrical and mechanical isotropy in the XY plane, a feature unique to CuClad. No other woven or nonwoven fiberglass-reinforced PTFE-based laminates make this claim.

What does in-plane isotropy actually mean for a PCB engineer? In a standard unidirectional-ply laminate, the dielectric constant is slightly different depending on whether you’re measuring along the fiber direction or perpendicular to it. That anisotropy is small — typically less than 1% — but in circuits sensitive to dielectric constant uniformity, it translates to measurable variation in characteristic impedance and signal propagation velocity depending on trace orientation. For filters, couplers, and low noise amplifiers where Dk uniformity is critical, that variation matters.

Designers have found this degree of isotropy critical in some phased array antenna applications. In a large planar phased array, you’ll have traces running in multiple orientations across the aperture. If your substrate has directional Dk variation, elements oriented along the fibers will have slightly different electrical performance from elements oriented perpendicular to them — and that manifests as phase and amplitude imbalance across the array.

CuClad 250’s cross-plied construction eliminates that variable by making the electrical properties identical in both X and Y axes. It’s a structural detail that makes a real difference in precision circuits.

Arlon CuClad 250 Key Properties and Datasheet Overview

Electrical Properties

Property	Value	Notes
Dielectric Constant (Dk)	2.40 – 2.60	Varies by grade and thickness
Dissipation Factor (Df)	0.0009 – 0.0022	X-band (10 GHz)
Dk Stability vs. Frequency	Stable across RF/microwave range
Dk Uniformity	Excellent	Cross-ply construction
XY Plane Isotropy	True electrical isotropy	Unique to CuClad family

Mechanical and Physical Properties

Property	Value / Description
Construction	Cross-plied woven fiberglass / PTFE composite
Dimensional Stability	Better than non-woven PTFE laminates
Thermal Expansion	Lower in all directions vs. lower-glass CuClad grades
Water Absorption	Very low (PTFE-based)
Mechanical Strength	Approaches conventional substrates (higher glass loading)
Copper Cladding	½ oz, 1 oz electrodeposited; other weights available

Available Grades: GT, GX, and LX

One source of confusion for engineers specifying CuClad 250 for the first time is the suffix letters. These designate different testing protocols, not fundamentally different materials:

Grade Suffix	Test Frequency	Use Case
GT (e.g., CuClad 250GT)	1 MHz	General procurement, standard QC
GX (e.g., CuClad 250GX)	10 GHz	Preferred for microwave design verification
LX (e.g., CuClad 250LX)	Per-sheet, with certificate of analysis	Critical performance applications

The electrical properties of CuClad 250GT and CuClad 250GX are tested at 1 MHz and 10 GHz respectively. For critical performance applications, CuClad products may be specified with the “LX” testing grade — this designates that each sheet will be tested individually and a test report will be issued with the order.

For any serious microwave design work, GX (10 GHz tested) is the relevant specification. GT figures measured at 1 MHz don’t reflect the Dk your design will see at microwave frequencies. If you’re quoting from a datasheet that only shows 1 MHz data, you’re working from numbers that don’t represent real operating conditions for RF circuits.

The LX grade is worth the premium on programs where lot-to-lot dielectric constant consistency is a hard requirement — defense production programs with tightly controlled electrical performance specs, for example.

Available Thicknesses and Dk Options

From the Arlon Microwave & RF Materials Guide, CuClad 250GX is available in the following standard configurations:

Thickness (inches)	Thickness (mm)	Available Dk Options
0.004″	0.102	2.40
0.010″	0.254	2.48, 2.55
0.015″	0.381	2.44, 2.48, 2.55
0.020″	0.508	2.45, 2.48, 2.50, 2.55
0.030″	0.762	2.40, 2.45, 2.50, 2.55
0.031″	0.787	2.45, 2.50, 2.55
0.047″	1.194	2.50
0.060″	1.524	2.40, 2.45, 2.50, 2.55

Master sheet sizes are 36″ × 48″ (non-cross-plied) and 36″ × 36″ (cross-plied configuration). When ordering, always specify dielectric constant, thickness, cladding weight, panel size, and testing grade. Since the Dk range for this material is 2.40–2.60, you’re selecting a specific nominal Dk within that range — not a fixed value like single-Dk materials.

The CuClad 250 Design Advantage: Higher Glass Loading in Practice

The headline spec on CuClad 250 is that it uses a higher fiberglass/PTFE ratio to provide mechanical properties approaching those of conventional substrates, with better dimensional stability and lower thermal expansion in all directions compared to lower-glass CuClad grades.

Let’s unpack why that matters for real PCB designs.

Dimensional Stability and Registration

High layer count multilayer boards depend on consistent layer-to-layer registration to meet controlled impedance tolerances and via-to-pad alignment requirements. PTFE materials with very low fiberglass content can be dimensionally unstable during processing — they shrink and move more than higher-glass materials as they’re processed through lamination, etching, and drilling.

CuClad 250’s higher glass content acts as a dimensional stabilizer. The woven fiberglass structure constrains in-plane movement during thermal processing steps. Compared to nonwoven PTFE laminates of similar dielectric constants — which use random-fiber reinforcement — the woven glass structure provides greater dimensional stability and better Dk uniformity across the panel.

Lower Thermal Expansion

Lower thermal expansion in all directions, compared to the lower-glass CuClad grades, translates directly to reduced stress on plated-through holes and solder joints during thermal cycling. CuClad 250 is still a PTFE-based material, so it doesn’t match the Z-axis CTE performance of ceramically loaded PTFE laminates like CLTE. But within the woven PTFE family, the higher glass loading in CuClad 250 gives it measurably better CTE characteristics than CuClad 217, making it a more reliable choice for multi-layer boards that will see significant thermal cycling.

Processability

One practical advantage that doesn’t get enough attention in datasheets: CuClad 250 is easier to fabricate than low-glass PTFE materials. Its higher fiberglass content gives it better rigidity and drill response. Boards are less prone to the micro-tearing and smearing that can occur when drilling very soft, high-PTFE-ratio materials. For shops doing low-volume defense microwave work alongside higher-volume standard build work, the reduced process complexity of CuClad 250 compared to pure PTFE products is a real operational benefit.

Where Arlon CuClad 250 Fits: Applications

The combination of low loss, X-Y isotropy, and mechanical robustness makes Arlon CuClad 250 a natural match for specific application categories:

Military Electronics: Radars, ECM, and ESM Systems

CuClad 250’s primary defense application history is in military electronics — radars, electronic countermeasure (ECM) systems, and electronic support measures (ESM). These systems typically require microwave PCBs that combine good RF performance with genuine mechanical durability: they get mounted in aircraft, ships, and ground vehicles that impose vibration and shock loads that bench-top electronics never see. CuClad 250’s near-conventional-substrate mechanical properties help boards survive those environments while maintaining electrical performance.

Microwave Filter, Coupler, and LNA Designs

These properties make CuClad an attractive choice for filters, couplers, and low noise amplifiers. For these circuits, Dk uniformity across the panel is critical — variations in local dielectric constant translate directly to center frequency shift in filters and to loss and directivity variation in couplers. CuClad 250’s cross-plied woven construction, combined with Arlon’s PTFE-coating process control, delivers the Dk consistency these designs require.

In LNA designs specifically, the low dissipation factor of CuClad 250 (as low as 0.0009 at X-band in the lower-Dk grades) matters for noise figure. Every tenth of a dB counts in an LNA front end, and laminate insertion loss contributes directly to cascaded noise figure.

Phased Array Antenna Substrates

True X-Y isotropy is critical in some phased array antenna applications. Large phased arrays — particularly those using distributed corporate feed networks or beamforming networks etched directly into the substrate — are precisely the applications where directional Dk variation shows up as measurable array performance degradation. CuClad 250’s cross-ply construction is designed to eliminate this concern.

Power Dividers and Combiners

In power divider and combiner networks, consistent Dk and low loss across the full circuit area determine port-to-port balance and insertion loss respectively. CuClad 250’s panel-wide Dk uniformity enables reproducible power divider performance across production lots — a significant advantage in defense production programs where every board must pass the same electrical acceptance test.

For a comprehensive view of the broader Arlon PCB laminate portfolio — including the ceramic-filled CLTE family, polyimide products, and high-frequency epoxy systems — it’s worth reviewing the full lineup to understand where CuClad 250 fits relative to other design options.

CuClad 250 vs. CuClad 217 and CuClad 233: How to Choose Within the Family

Engineers new to the CuClad family sometimes aren’t sure which grade to spec. Here’s the practical guidance:

Parameter	CuClad 217	CuClad 233	CuClad 250
Dk (nominal)	2.17 – 2.20	2.33	2.40 – 2.60
Df (X-band)	~0.0009 (lowest)	~0.0013	~0.0015–0.0022
Fiberglass/PTFE ratio	Low	Medium	High
Dimensional stability	Moderate	Better	Best in family
Thermal expansion	Higher	Moderate	Lowest in family
Mechanical rigidity	Lower	Moderate	Best in family
Signal propagation speed	Fastest	Moderate	Slower vs. 217
Best for	Lowest loss, fastest propagation	Balanced loss / mechanical	Mechanically demanding, ECM/radar

CuClad 217 is the right choice when you need the absolute lowest Dk and loss — the fastest signal propagation and best Df in the CuClad family. CuClad 233 balances both. CuClad 250 is the right choice when mechanical durability, dimensional stability, and fabrication robustness matter as much as electrical performance — which is most defense hardware.

CuClad 250 vs. Rogers RT/duroid 5880

Since Rogers acquired Arlon in 2015, CuClad 250 effectively competes with Rogers’ own RT/duroid 5880 in some applications. The comparison is informative:

Parameter	Arlon CuClad 250	Rogers RT/duroid 5880
Dk (10 GHz)	2.40 – 2.60	2.20
Df (10 GHz)	~0.0015–0.0022	0.0009
Construction	Cross-plied woven glass/PTFE	PTFE/microfiber glass
XY Isotropy	True (cross-ply)	Good but non-woven
Dimensional stability	Better (woven)	Moderate
Mechanical strength	Higher	Moderate
Primary strength	Dk uniformity, isotropy, mechanicals	Ultra-low loss

RT/duroid 5880 wins on raw Df and Dk. CuClad 250 wins on dimensional stability and cross-ply isotropy. They’re different tools for different jobs, and understanding which axis matters most for your circuit determines which belongs on your BOM.

Fabrication Guidelines for CuClad 250 PCBs

CuClad 250 processes similarly to other woven PTFE laminates, but the higher glass content makes it somewhat more forgiving than pure PTFE or very-high-PTFE-ratio materials.

Drilling

Use highly polished carbide tools. Repointed (resharpened) bits are not recommended on PTFE-based materials because even small amounts of dulling lead to smearing of the PTFE matrix around hole walls. Panels can be drilled in stacks based on total thickness — standard entry and backup board materials apply. Use firm clamping to prevent material lift during drilling.

Surface Preparation for Bonding

PTFE surfaces require activation before bonding or plating. Inert gas plasma or sodium etch processes are standard approaches. Adhesion to copper surfaces can be improved with an aggressive micro-etch such as ammonium persulfate prior to bonding. It is best to proceed to lamination as quickly as possible after surface activation — PTFE surfaces relax over time and adhesion windows are finite.

Routing

Use two-flute, slow-spiral, micrograin carbide upcut endmills for routing. Support PTFE material with rigid entry and backup materials to prevent lifting and tearing at the routed edge. Typical routing parameters for a 0.062″ cutter: spindle speed around 15,000 rpm, table feed rate approximately 15 inches per minute — adjust based on your specific machine and material thickness.

Storage

Store CuClad 250 flat in a cool, dry location away from direct sunlight. Avoid copper oxidation and panel contamination. Unlike moisture-sensitive thermoset prepregs, PTFE materials have minimal moisture sensitivity, but maintaining clean, oxidation-free copper surfaces is important for downstream bonding steps.

Useful Resources for Engineers Working with CuClad 250

Resource	Description	Where to Find It
Arlon CuClad Series Datasheet	Full electrical, mechanical, and dimensional specs	midwestpcb.com/data_sheets/ArlonCuClad.pdf
Rogers CuClad 250 Product Page	Current Rogers-era product info and Laminate Properties Tool	rogerscorp.com/advanced-electronics-solutions/cuclad-series-laminates/cuclad-250-laminates
Arlon Microwave & RF Materials Guide	Full PTFE laminate portfolio comparison and thickness/Dk tables	integratedtest.com/wp-content/uploads/2021/08/ArlonMaterials.pdf
Fabrication Guidelines: DiClad, CuClad, IsoClad	Process guidelines for PTFE woven laminates	Available via rfglobalnet.com/doc/rf-microwave-laminates-cuclad-0001
MatWeb — Arlon CuClad 250	Material property database with key specs	matweb.com
Hughes Circuits CuClad Overview	Fabricator’s material reference with CuClad family data	hughescircuits.com
IPC-4103 Specification	Industry standard covering PTFE-based laminates	ipc.org

Always pull the latest revision of the Rogers/Arlon datasheet directly from Rogers Corporation or an authorized distributor — specifications have been updated since the original Arlon publications and Rogers-era documentation is authoritative for current production material.

Frequently Asked Questions About Arlon CuClad 250

Q1: What is the difference between CuClad 250GT and CuClad 250GX?

The GT and GX suffixes designate the test frequency at which the dielectric constant is measured and certified. CuClad 250GT is tested at 1 MHz, which is standard for broad material qualification but not particularly relevant to microwave circuit performance. CuClad 250GX is tested at 10 GHz — the frequency range your circuits are actually operating in. For any microwave PCB design work, always specify and design from GX data. The 10 GHz Dk value is what your EM simulator needs to produce accurate results.

Q2: Why does CuClad 250 have a range of dielectric constants (2.40–2.60) rather than a single fixed value?

The Dk range reflects the fact that the fiberglass/PTFE ratio — and therefore the composite dielectric constant — varies slightly across the thickness range of available materials. Thinner substrates tend toward the lower end of the range, while thicker substrates can achieve higher Dk values due to changes in the glass volume fraction. When you specify CuClad 250, you select a specific nominal Dk option (e.g., 2.50) from the available options at your chosen thickness. Your design and EM simulations should use that specific nominal value with an understanding of the typical lot-to-lot tolerance.

Q3: Can CuClad 250 be processed in a standard FR-4 shop?

Partially. CuClad 250’s higher glass content makes it more FR-4-like than lower-glass PTFE laminates, but important process differences remain. PTFE surfaces require specific surface activation (plasma or sodium etch) before plating or bonding — standard FR-4 oxide processes don’t apply. Lamination bonding plies for PTFE multilayers require much higher press temperatures than standard epoxy prepreg. Drilling with repointed bits is not recommended. A shop with some PTFE experience can handle CuClad 250, but a pure FR-4 shop without PTFE process knowledge will run into surface adhesion and multilayer bonding problems. Always verify your fabricator’s PTFE process capabilities.

Q4: What bonding materials are used to build CuClad 250 multilayers?

CuClad products can be bonded using Arlon’s CuClad 6700 and CuClad 6250 thermoplastic bonding films, or Arlon’s CLTE-P bonding ply (the same prepreg used with the CLTE laminate family), or Arlon’s GenClad 280 hybrid thermoset/thermoplastic prepreg. Each has different process temperature requirements and Dk properties. For circuits where the bondline Dk must match the laminate Dk closely — stripline designs, controlled impedance inner layers — CLTE-P or GenClad 280 with a well-characterized Dk are the better choices over bare bonding films.

Q5: How does the CuClad 250 cross-ply construction benefit filter and coupler designs specifically?

Bandpass filters and directional couplers are among the most Dk-sensitive circuits in microwave design. A small change in local dielectric constant shifts the resonant frequency of filter stubs and the coupling coefficient of gap couplers. If your laminate has directional Dk variation — higher along the fiber direction than perpendicular to it — traces parallel to the fibers will have slightly different electrical length than identical traces oriented 90° away. In a filter or coupler that combines orthogonally oriented elements, this shows up as asymmetry in the frequency response. CuClad 250’s cross-ply construction ensures the Dk your circuits see is the same regardless of trace orientation, so the only Dk variables left in your design are the well-characterized tolerances from lot to lot — not the orientation-dependent variation that complicates other PTFE laminate designs.

Suggested Meta Description:

Arlon CuClad 250 is a cross-plied woven PTFE/fiberglass laminate with Dk 2.40–2.60 and low loss for military radar, ECM, and microwave filter PCBs. Complete guide to CuClad 250 properties, GT vs GX vs LX grades, fabrication tips, and comparison with CuClad 217 and Rogers RT/duroid 5880.

Everything RF and microwave PCB engineers need to know about Arlon CuClad 233 — electrical specs, cross-plied construction explained, fabrication guidelines, LX testing grade, and comparison with CuClad 217 and 250.

If you’ve been designing RF and microwave circuits for any length of time, you’ve almost certainly run into a situation where material selection came down to a careful trade-off: do you push for the absolute lowest loss at the cost of mechanical reliability, or accept a small electrical compromise in exchange for a substrate that your fabricator can actually process without heartburn? Arlon CuClad 233 is one of those materials that was engineered specifically to live in that middle ground — and it does it well.

This guide covers everything you need to know about Arlon CuClad 233 as a working PCB design or manufacturing engineer: what it is, why the cross-plied construction matters, the full specification profile, fabrication considerations, typical applications, and how it compares to its siblings in the CuClad family.

What Is Arlon CuClad 233?

Arlon CuClad 233 is a cross-plied, woven fiberglass and PTFE composite laminate with a nominal dielectric constant (Dk) of 2.33. It was originally developed by Arlon Materials for Electronics and is now manufactured and marketed under Rogers Corporation, which acquired Arlon LLC. It sits as part of the broader CuClad series alongside CuClad 217 (Er 2.17–2.20) and CuClad 250 (Er 2.40–2.60).

The defining characteristic of CuClad 233 is its medium fiberglass-to-PTFE ratio. This is a deliberate engineering decision. CuClad 217 uses a very high PTFE content to achieve the lowest possible Dk and dissipation factor (Df), but that comes at the cost of mechanical softness and dimensional sensitivity. CuClad 250 swings the other way, adding more glass to bring mechanical properties closer to conventional substrates. CuClad 233 sits between them — maintaining a low Dk and low loss profile while providing noticeably better dimensional stability and handling characteristics than CuClad 217.

The cross-plied construction is worth its own discussion. In CuClad products, alternating plies of PTFE-coated fiberglass cloth are oriented at 90° to each other. This is not standard for PTFE-based laminates — DiClad products, for example, use parallel-plied construction. The cross-plied architecture of CuClad 233 delivers true electrical and mechanical isotropy in the X-Y plane, which is a property that cannot be claimed by most woven or non-woven fiberglass PTFE laminates. For engineers working on phased array antennas or precision microwave circuits where symmetry of electrical behavior in both axes matters, this is a genuinely important advantage.

Arlon CuClad 233 is currently handled and manufactured under the Rogers/Arlon brand. If you’re sourcing boards in this material or qualifying a fabricator, working with a manufacturer experienced in Arlon PCB processing is strongly recommended.

Arlon CuClad 233 Full Specification Table

The following table presents the typical electrical and mechanical properties for Arlon CuClad 233. These are typical values — not specification limits. Always consult the official Rogers/Arlon datasheet for your specific thickness and lot requirements.

Property	Value	Test Method
Dielectric Constant (Dk) @ 10 GHz	2.33	IPC TM-650 2.5.5.5
Dissipation Factor (Df) @ 10 GHz	0.0013	IPC TM-650 2.5.5.5
Dielectric Constant @ 1 MHz	2.33	IPC TM-650 2.5.5.3
Dissipation Factor @ 1 MHz	0.0010	IPC TM-650 2.5.5.3
Volume Resistivity	> 10^8 MΩ·cm	IPC TM-650 2.5.17
Surface Resistivity	> 10^7 MΩ	IPC TM-650 2.5.17
Moisture Absorption	< 0.10%	IPC TM-650 2.6.2
Peel Strength (1 oz Cu)	≥ 6 lbs/in	IPC TM-650 2.4.8
CTE (X-axis)	~16 ppm/°C	IPC TM-650 2.4.41
CTE (Y-axis)	~16 ppm/°C	IPC TM-650 2.4.41
CTE (Z-axis)	~200 ppm/°C	IPC TM-650 2.4.41
Tensile Strength (X-direction)	~28 MPa	ASTM D882
Thermal Conductivity	~0.26 W/m·K	ASTM E1461
Standard Panel Size (cross-plied)	36″ × 36″	—
Standard Panel Size (parallel-plied)	36″ × 48″	—

The Dk of 2.33 is extremely stable across frequency — a property inherent to PTFE-based materials. Rogers publishes curves showing minimal Dk drift from 1 MHz through well above 20 GHz, and this holds up in practice. For circuit designers, that stability translates directly to predictable impedance across the operating band of the design without frequency-dependent corrections.

Available Thickness and Copper Cladding Options

CuClad 233 is available in a range of standard thicknesses with electrodeposited (ED) copper on both sides.

Thickness (inches)	Thickness (mm)	Typical Copper Weights Available
0.010″	0.254	½ oz, 1 oz
0.020″	0.508	½ oz, 1 oz, 2 oz
0.031″	0.787	½ oz, 1 oz, 2 oz
0.062″	1.575	½ oz, 1 oz, 2 oz
0.125″	3.175	1 oz, 2 oz

CuClad laminates are also available bonded to a heavy metal ground plane. Aluminum, brass, or copper plates serve as both an integral heat sink and mechanical support structure, which is relevant for power module assemblies where thermal management and structural rigidity are both constraints. Rolled (RA) copper foil is also available on request and is preferred by some engineers for fine-line circuits because of its smoother surface profile.

When ordering, you must specify dielectric constant, thickness, copper cladding weight, panel size, and any special considerations such as the “LX” testing grade.

The LX Testing Grade: What It Means and When You Need It

This is a detail that trips up engineers who are new to the CuClad product line. For standard orders, Arlon/Rogers performs production testing on a sampling basis. For critical performance applications, CuClad products — including CuClad 233 — can be ordered with an “LX” designation. This means that every individual sheet is tested separately, and a dedicated test report is issued with the order.

In practice, this matters in two scenarios: military and defense electronics where lot traceability and individual sheet performance certification are required by contract, and precision microwave assemblies where Dk uniformity across the lot directly impacts yield in tuning-sensitive products like narrow-bandpass filters or phase-matched diplexers. The LX grade adds cost and lead time, but for the right application, it eliminates a major source of yield variance at the system assembly stage.

Cross-Plied Construction: The Key Differentiator of CuClad 233

It’s worth spending more time on why the cross-plied construction of CuClad 233 sets it apart from other woven PTFE laminates.

In a standard woven fiberglass PTFE laminate with parallel-ply construction (like DiClad products), all the PTFE-coated fiberglass cloth layers run in the same orientation. This means the material can exhibit slightly different electrical and mechanical behavior in the warp direction versus the fill direction of the weave. For many applications, this difference is small enough to ignore. But for applications that rely on symmetric electromagnetic behavior — phased array antennas, balanced mixers, precision coupler designs, and some radar front ends — that directional variance introduces errors that are difficult to compensate in design.

CuClad 233’s cross-plied construction, with alternating plies oriented 90° to each other, averages out these directional differences and delivers genuine electrical and mechanical isotropy in the X-Y plane. No other woven or non-woven fiberglass-reinforced PTFE laminate makes this claim, according to Arlon’s documentation. For phased array antenna engineers in particular, this isotropy eliminates one of the systematic error sources in beam-steering performance.

Why Dk 2.33 Positions CuClad 233 Uniquely in the Low-Loss Laminate Market

A Dk of 2.33 places CuClad 233 in the low-end of the dielectric constant range for woven glass PTFE laminates, just above pure PTFE (Dk ≈ 2.1) and well below standard ceramics or even ceramic-filled PTFE composites. To understand where this sits in practical design terms, the table below compares CuClad 233 against frequently used reference materials.

Material	Nominal Dk	Df @ 10 GHz	Primary Trade-off
Rogers RT/duroid 5880	2.20	0.0009	Very low loss, softer, less stable
Arlon CuClad 217	2.17	~0.0009	Lowest loss, softest mechanically
Arlon CuClad 233	2.33	~0.0013	Balance of loss + mechanical stability
Arlon CuClad 250GT	2.55	~0.0018	Better mechanical, slightly higher loss
Rogers RO4003C	3.55	0.0027	Thermoset, excellent stability, limited loss
Standard FR4	4.2–4.5	0.020+	Low cost, poor high-frequency performance

At a Df of 0.0013 at 10 GHz, CuClad 233 delivers insertion loss performance well below what any thermoset material (including Rogers RO4003) can achieve. The performance gap becomes more pronounced as frequency rises into Ka-band and above. For X-band radar components, satellite communications, and precision microwave passive components, this loss difference translates directly to system noise figure, filter insertion loss, and amplifier efficiency.

Typical RF and Microwave Applications for Arlon CuClad 233

The combination of low Dk, very low dissipation factor, X-Y plane isotropy, and better-than-CuClad-217 mechanical stability positions CuClad 233 well for a specific and important range of applications.

Application Category	Specific Use Cases
Military & Defense Electronics	Radar front ends (ECM, ESM, AESA arrays), electronic warfare systems, missile seekers
Precision Passive Microwave	Narrowband bandpass filters, directional couplers, hybrids, Wilkinson dividers
Low Noise Amplifier Boards	LNA input networks where insertion loss directly sets system noise figure
Phased Array Antennas	Applications requiring true XY isotropy for consistent beam steering
Satellite Communications	Uplink/downlink feed networks, VSAT terminal circuits
High-Speed Signal Interconnects	Applications leveraging low Dk for reduced propagation delay
Test & Measurement	Calibration substrates, microwave fixtures requiring stable and known Dk

The military electronics application domain is particularly well aligned with CuClad 233’s properties. Radar systems operating at S, C, X, or Ku band require extremely low insertion loss in their receive chains, tight phase matching in distributed components, and reliable long-term performance across wide temperature ranges. The PTFE base of CuClad 233 offers inherent chemical inertness and low moisture absorption, both of which contribute to stable performance in harsh field environments.

Arlon CuClad 233 vs. CuClad 217 vs. CuClad 250: Which One Should You Use?

Engineers regularly face the choice between the three main CuClad variants. Here’s a practical breakdown.

Parameter	CuClad 217	CuClad 233	CuClad 250GT/GX
Nominal Dk	2.17–2.20	2.33	2.55
Dissipation Factor @ 10 GHz	~0.0009	~0.0013	~0.0018
Fiberglass/PTFE Ratio	Low	Medium	High
Mechanical Robustness	Lower	Medium	Approaching conventional
Dimensional Stability	Lower	Better	Best in series
Construction	Cross-plied	Cross-plied	Cross-plied
XY Plane Isotropy	Yes	Yes	Yes
Best Fit	Lowest loss priority	Balanced performance	Mechanical stability priority

Choose CuClad 217 when insertion loss and dielectric constant are the dominant constraints and your fabricator has the capability to handle the softest substrate in the family. Choose CuClad 233 when you need very low loss but also need a substrate that handles better through fabrication, or when dimensional stability matters more than pushing Dk to the absolute minimum. Choose CuClad 250GT or 250GX when you need the mechanical behavior of CuClad to approach conventional PCB materials — the additional glass loading makes it more forgiving in high-volume production environments.

Fabrication Guidelines for Arlon CuClad 233

Processing PTFE-based laminates is materially different from FR4 fabrication. CuClad 233, while better behaved than CuClad 217 due to its higher glass content, still requires PTFE-specific process steps. Fabricators who approach it as if it were a standard FR4 or even a thermoset high-frequency material will have problems.

Storage and Handling Before Fabrication

PTFE laminates absorb very little moisture (CuClad 233 is rated below 0.10%), but they are sensitive to contamination. Store panels in a clean, controlled-humidity environment and process them promptly after opening packaging. Unlike FR4, PTFE does not benefit from a pre-bake to drive off absorbed moisture — the concern is surface contamination that affects plating adhesion.

Cutting and Routing

CuClad 233 can be cut with standard shearing equipment, but PTFE’s softness means clean tooling is essential. Dull router bits cause smearing rather than cutting, which leads to ragged edges and potential delamination. Use sharp carbide tools, maintain appropriate feed rates for PTFE-based material, and ensure adequate chip evacuation to prevent heat buildup.

Drilling

Keep stack heights low — one to two panels per drill stack is the standard recommendation for PTFE materials. Use appropriate entry material (thin aluminum) and backup material to support clean hole entry and exit. Inspect hole walls before plating. PTFE smear inside holes is the most common cause of PTH reliability failures in PTFE laminates.

PTFE Surface Activation (Critical Step)

PTFE is chemically inert — that’s one of the reasons it’s electrically excellent, but it means electroless copper will not adhere to raw PTFE hole walls. Before electroless copper deposition, the hole walls must be activated using either a sodium naphthalate etchant or a plasma etch process. This step is non-negotiable. Inadequate activation is the leading cause of PTH barrel failure and delamination at via interfaces in PTFE multilayer boards.

If your fabricator cannot confirm they perform this step — and specify which activation chemistry they use — consider that a disqualifying gap in their process qualification.

Etching and Line Definition

Standard cupric chloride or ammoniacal etchants work well with CuClad 233’s electrodeposited copper. Peel strength is typically above 6 lbs/inch for 1 oz copper, which is adequate for fine-line work. Handle panels with care, as PTFE-based boards are more sensitive to edge delamination from rough handling than thermoset materials.

Soldering and Assembly

CuClad 233’s low moisture absorption is an asset during reflow assembly — there’s minimal risk of moisture-induced delamination during the thermal excursion. The material is compatible with standard SMT reflow profiles. However, PTFE has low thermal conductivity (~0.26 W/m·K), so heat does not spread as quickly as in ceramic or higher-conductivity substrates. Profile your oven based on actual thermal measurements on the populated board, not assumed FR4 behavior.

Common Design Mistakes When Using CuClad 233

From a practical design standpoint, a few errors come up repeatedly with this material.

Not accounting for Dk variation with thickness. The nominal Dk of 2.33 is measured at specific laminate thicknesses. Very thin laminates can show slightly different effective Dk values. If you’re designing for precise impedance targets — particularly for 50-ohm lines on thin substrates — verify the effective Dk from the Rogers/Arlon Laminate Properties Tool or request actual measured data for your specific thickness.

Using FR4-based transmission line calculators. A 50-ohm microstrip on CuClad 233 is geometrically very different from one on FR4. The lower Dk requires wider traces for the same impedance on the same substrate thickness, which also changes the EM coupling behavior around corners and gaps. Always use accurate Dk and substrate thickness in your line width calculations.

Ignoring Z-axis CTE in multilayer designs. At approximately 200 ppm/°C, the Z-axis CTE of CuClad 233 is high compared to copper (~17 ppm/°C). This mismatch drives barrel fatigue in through-hole vias and plated holes during thermal cycling. For multilayer designs in high-thermal-cycle environments, carefully evaluate your via aspect ratios and consider whether micro-via or blind via constructions can reduce the at-risk barrel length.

Specifying standard grade when LX is needed. If your product has mil-spec traceability requirements or if you’re producing a lot-sensitive circuit like a narrowband filter bank, standard sampling-grade test certification may not be sufficient. Specify LX grade at the time of ordering.

Useful Resources for CuClad 233 Engineers

Resource	Description	Link
Rogers CuClad Series Datasheet	Official spec sheet covering CuClad 217, 233, and 250	rogerscorp.com
Rogers Laminate Properties Tool	Interactive tool for filtering and comparing laminate properties	Rogers PCB Tools
MatWeb CuClad 233 Entry	Third-party material database with converted property units	MatWeb
IPC TM-650 Test Methods	Standard test procedures referenced in the datasheet	IPC.org
Arlon/Rogers PCB Fabrication Resources	Manufacturing guidelines for CuClad and other PTFE laminates	RayPCB Arlon PCB
Midwest PCB CuClad Datasheet PDF	Mirror of the CuClad series datasheet with all three variants	midwestpcb.com

5 Frequently Asked Questions About Arlon CuClad 233

1. What is the difference between CuClad 233 and DiClad 233?

Both are Arlon/Rogers PTFE-fiberglass laminates targeting a similar Dk range, but the construction differs fundamentally. CuClad products use cross-plied construction (alternating plies at 90° to each other), which delivers electrical and mechanical isotropy in the X-Y plane. DiClad products use parallel-plied construction, where all fiberglass plies run in the same direction. The cross-plied CuClad 233 is preferred for applications where XY isotropy matters — phased arrays, balanced circuits, and directional couplers. DiClad variants are sometimes preferred for specific single-axis applications or where cost is a stronger driver.

2. Can Arlon CuClad 233 be used in multilayer PCB designs?

Yes, but multilayer construction with PTFE-based laminates requires compatible bonding materials. You cannot use standard FR4 prepregs as bonding plies between CuClad 233 cores — the mismatch in CTE, glass transition temperature, and resin chemistry leads to delamination and reliability failures. Use Rogers-specified bondply or bonding films designed for PTFE-based multilayer construction, and confirm your fabricator’s multilayer process for PTFE materials before committing to a design.

3. Is CuClad 233 appropriate for commercial wireless infrastructure, or is it mainly a military substrate?

The original application focus for CuClad 233 was military and high-performance microwave electronics, given its very low loss and cross-plied isotropy. That said, the material is applicable wherever Df below 0.0015 is needed and mechanical robustness is more important than the absolute lowest Dk. Commercial satellite terminal circuits, precision test fixtures, LNA boards for base station receivers, and high-performance VSAT equipment are all valid commercial applications for CuClad 233.

4. How does CuClad 233 handle at millimeter-wave frequencies (above 30 GHz)?

PTFE-based materials, including CuClad 233, generally maintain good dielectric properties well into the millimeter-wave frequency range. Dk stability across frequency is one of PTFE’s intrinsic advantages. However, at millimeter-wave frequencies, surface roughness of the copper foil becomes a significant loss mechanism — often dominant over the dielectric loss. For mmWave designs on CuClad 233, specify low-profile or rolled annealed copper foil to minimize conductor roughness losses, and account for the copper roughness contribution in your insertion loss budget.

5. What is the best way to confirm the actual Dk of a CuClad 233 lot before fabrication?

Rogers/Arlon provides a standard test report with each order for the LX testing grade, with lot-specific Dk and Df measurements. For standard-grade material, you can request test data from your distributor’s incoming inspection records. If you need to verify independently, the IPC TM-650 2.5.5.5 test method (full-sheet resonator or stripline resonator method at 10 GHz) is the standard approach used in the datasheet and can be repeated in-house or at a qualified test lab. Some engineers also use time-domain reflectometry (TDR) on characterization coupons included in the production panel, which provides real-time Dk confirmation based on the actual processed board.

Final Thoughts on Arlon CuClad 233

Arlon CuClad 233 has maintained a strong position in the high-frequency laminate market precisely because it occupies a genuinely useful operating point: low enough dissipation factor to compete with the best PTFE materials in its class, combined with dimensional stability and mechanical handling characteristics that make it a realistic production substrate rather than a laboratory curiosity.

For military radar, ECM, and ESM systems where performance is non-negotiable and the LX grade provides the individual-sheet traceability these programs require, CuClad 233 remains a first-choice substrate. For precision microwave passive components where the cross-plied XY isotropy eliminates a systematic error source, it provides a competitive advantage that is genuinely hard to replicate with standard parallel-plied materials.

If you’re working with this material for the first time, the most important thing to get right is the fabrication process — specifically the PTFE activation step for plated holes and drilling parameters. Get those right with a qualified fabricator, and CuClad 233 will deliver exactly the performance its datasheet promises.

Arlon CuClad 218 is an ultra-low Dk (~2.17–2.20) cross-plied PTFE/woven fiberglass laminate for military radar, phased arrays, and precision microwave circuits. Full specs, comparisons, fabrication tips & FAQs inside.

If you’ve been searching for Arlon CuClad 218, you’re likely chasing one of two things: either you’ve seen the designation in older project documentation and need to source a compatible material, or you’re evaluating ultra-low dielectric constant PTFE laminates for a high-frequency design and want to understand exactly what this product delivers. Either way, this guide has you covered.

The name “CuClad 218” reflects a specific variant within Arlon’s historic CuClad 217 family — a group of cross-plied, woven fiberglass/PTFE composite laminates that offer the lowest dielectric constants available in fiberglass-reinforced PTFE substrates. When Rogers Corporation acquired Arlon LLC in 2015, the CuClad family was consolidated under Rogers’ product portfolio, but engineers, procurement teams, and older design files still reference these materials by their original Arlon designations. Understanding what you’re really dealing with — and how to spec it correctly today — is the practical purpose of this article.

What Is Arlon CuClad 218? Product Family Context

Arlon CuClad 218 belongs to the CuClad 217 product family, which Arlon specified with dielectric constant options of 2.17 and 2.20. A “CuClad 218” designation reflects an intermediate Dk target (~2.18) within this family, ordered to specific dielectric constant, thickness, and copper weight parameters. This level of flexibility in dielectric constant specification is a defining characteristic of the CuClad series — Arlon controlled the fiberglass-to-PTFE ratio with enough precision that specific Dk values within the ultra-low range could be produced to order.

The broader CuClad series from Arlon covers three main Dk ranges: the CuClad 217 family at the ultra-low end (Dk 2.17–2.20), CuClad 233 in the mid-range (Dk 2.33), and CuClad 250 at the upper end (Dk 2.40–2.60). The CuClad 218 specification sits firmly in the lowest-loss tier of this family, making it one of the most electrically transparent laminate options available for microwave and RF PCB design.

For engineers working with an Arlon PCB manufacturer today, specifying CuClad 218 means selecting from the CuClad 217 family at a Dk of approximately 2.17–2.20, with the fabricator or material supplier confirming the closest available specification to your target.

Material Composition: What Makes CuClad 218 Different

The properties of Arlon CuClad 218 trace directly to its material construction — a carefully balanced system of three components working together.

High PTFE-to-Glass Ratio

The defining feature of the CuClad 218 (and the broader CuClad 217 family) is its low fiberglass-to-PTFE ratio. Compared to other members of the CuClad series, CuClad 218 uses significantly more PTFE and less fiberglass reinforcement by volume. This is precisely what drives the ultra-low dielectric constant: PTFE itself has a Dk of approximately 2.1, so maximizing the PTFE fraction minimizes the composite’s Dk toward that theoretical lower bound.

The trade-off is that higher PTFE content means less mechanical reinforcement — the material is softer and more dimensionally sensitive than more heavily reinforced alternatives like CuClad 250. This is something fabricators need to manage, and something designers need to account for when specifying the material for mechanically demanding environments.

Cross-Plied Woven Fiberglass Construction

One of the most important and distinctive features of Arlon CuClad 218 is its cross-plied construction. Alternating layers of PTFE-coated fiberglass cloth are oriented at 90° to each other during laminate manufacture. The result is true electrical and mechanical isotropy in the XY plane — a characteristic that Arlon (and now Rogers) explicitly states is unique to the CuClad product line among all woven and non-woven fiberglass-reinforced PTFE laminates.

Why does this matter in practice? In antenna arrays, phased array radar systems, and precision microwave filters, performance depends on consistent electromagnetic behavior regardless of circuit orientation. A material that has different Dk values along different in-plane axes introduces direction-dependent impedance variations that are difficult to simulate and worse to troubleshoot. CuClad 218’s cross-plied isotropy eliminates this failure mode at the material level.

Stable PTFE Composite Base

PTFE’s non-polar molecular structure is what makes it inherently low-loss at microwave frequencies. There are no strongly polar bonds to interact with oscillating electric fields and convert signal energy into heat. The CuClad 218 composite retains this fundamental advantage of pure PTFE while gaining the dimensional stability and processability improvements that woven fiberglass reinforcement provides.

Arlon CuClad 218 Key Specifications

The following tables summarize the electrical, thermal, and mechanical properties relevant to PCB design and fabrication.

Electrical Properties

Property	Value	Test Condition
Dielectric Constant (Dk)	~2.17–2.20	X-band (8–12 GHz)
Dissipation Factor (Df)	0.0009	10 GHz
Dk Stability vs. Frequency	<1% variation	1 MHz to 20+ GHz
Dielectric Constant Uniformity	Better than non-woven PTFE	—

Thermal and Environmental Properties

Property	Value
Moisture Absorption	0.02%
Glass Transition Temperature (Tg)	>280°C
Maximum Operating Temperature	~260°C (lead-free compatible)
Outgassing	Low (NASA SP-R-0022A compliant)

Mechanical and Fabrication Properties

Property	Details
Construction	Cross-plied woven fiberglass/PTFE
Available Copper Weights	½ oz, 1 oz, 2 oz electrodeposited; rolled copper on request
Metal-Backed Options	Aluminum, brass, or copper ground plane available
Maximum Panel Size	36″ × 36″ (cross-plied), 36″ × 48″ (parallel plied)
Z-axis CTE	~246 ppm/°C
LX Testing Grade	Available — individual sheet test report issued

Understanding the Critical Numbers

Dissipation factor of 0.0009 at 10 GHz is benchmark performance. To put it in context: standard FR-4 runs 0.020 or higher. Even well-regarded hydrocarbon laminates like RO4350B come in at 0.0037 — more than four times higher. RO4003C is at 0.0027. In a system with 12 inches of microstrip trace at 18 GHz, the difference between 0.0009 and 0.0037 Df represents a very real difference in insertion loss that shows up in your noise figure or output power.

Moisture absorption of 0.02% is among the absolute lowest in the laminate industry. This matters for two reasons. First, water has a dramatically higher dielectric constant (~80) than any PCB substrate, so even trace moisture causes measurable Dk drift. Second, that Dk drift translates directly into impedance variation and phase error — intolerable in precision microwave circuits. At 0.02%, CuClad 218 effectively eliminates moisture as a performance variable across the full range of environmental conditions most electronics see in service.

Dk stability across frequency is the property that separates professional-grade RF laminates from everything else. CuClad 218’s Dk varies by less than 1% from 1 MHz to beyond 20 GHz. When you’re designing a broadband coupler, a wideband LNA matching network, or a multi-octave filter, this stability means your simulation matches your hardware — a relationship many FR-4 and even some mid-range RF laminate users have learned to doubt.

Arlon CuClad 218 vs. Competing Materials

Making the right material choice means understanding the trade-space. Here’s how CuClad 218 compares to the alternatives you’ll most likely encounter:

CuClad 218 vs. Rogers RT/duroid 5880

Parameter	Arlon CuClad 218	RT/duroid 5880
Dk (10 GHz)	~2.17–2.20	2.20
Df (10 GHz)	0.0009	0.0009
Reinforcement	Cross-plied woven glass	Random glass microfiber
XY Isotropy	True isotropy	Near-isotropic
Dimensional Stability	Better (woven glass)	Good
Cost	Comparable	Comparable
Typical Use	Military radar, phased arrays, precision filters	Aerospace, satellite, broadband antennas

Both materials deliver essentially identical loss performance (Df 0.0009). The key differentiation is construction: CuClad 218’s cross-plied woven glass gives it verified XY isotropy and typically better dimensional stability during lamination, while RT/duroid 5880’s random microfiber construction makes it more amenable to conformal or curved antenna applications. For flat, precision, multi-layer designs — especially phased arrays — CuClad 218’s cross-plied isotropy is a genuine design advantage.

CuClad 218 vs. Arlon CuClad 233

Parameter	Arlon CuClad 218	Arlon CuClad 233
Dk (X-band)	~2.17–2.20	2.33
Df (X-band)	0.0009	~0.0012
Glass Content	Lower	Medium
Dimensional Stability	Moderate	Better
Mechanical Strength	Lower	Higher
Best For	Maximum low-loss performance	Balance of loss and handling

CuClad 233 is the step up in mechanical robustness within the CuClad family. If your design can tolerate a slightly higher Dk and marginally higher loss tangent, CuClad 233 is easier to handle in a shop environment and offers better dimensional stability during multilayer lamination. CuClad 218 is the right choice when you need the absolute lowest loss and can accept the more demanding fabrication requirements.

CuClad 218 vs. Rogers RO4003C

Parameter	Arlon CuClad 218	Rogers RO4003C
Dk (10 GHz)	~2.17–2.20	3.55
Df (10 GHz)	0.0009	0.0027
Processing	PTFE-specialized	FR-4 compatible
XY Isotropy	True isotropy	Standard
Cost	Higher	Moderate
Best For	Ultra-low loss, precision RF	Commercial RF, 5G, 10–30 GHz designs

RO4003C processes like FR-4 and is the standard choice for commercial RF designs up to about 30 GHz where cost matters and the somewhat higher loss tangent is acceptable. CuClad 218 wins decisively on electrical performance — three times lower loss tangent, significantly lower Dk — but requires a fabricator with PTFE expertise. For military radar, high-sensitivity receivers, satellite receivers, and high-performance phased arrays, the performance gap justifies both the cost premium and the fabrication complexity.

Applications Where Arlon CuClad 218 Excels

The ultra-low dielectric constant and loss tangent of Arlon CuClad 218 make it a natural fit for specific application categories where inferior materials cause measurable system-level performance degradation.

Military Radar and Electronic Warfare Systems

Military radar — whether ground-based, airborne, or shipboard — demands the lowest possible insertion loss in its antenna feed networks and signal processing chains. In radar receivers, every 0.1 dB of unnecessary substrate loss directly degrades noise figure. In transmitters, unnecessary loss reduces effective radiated power. CuClad 218’s 0.0009 Df is among the lowest values available in any commercial laminate, and its XY plane isotropy ensures consistent performance across array elements.

Electronic countermeasure (ECM) and electronic support measure (ESM) systems have similar requirements. These systems process extremely wide bandwidths — often multi-octave — and rely on substrate materials whose electrical properties are consistent across that entire bandwidth. CuClad 218’s Dk stability from MHz through GHz ranges makes it well-suited to these broadband applications.

Phased Array Antennas

Phased arrays are arguably the most demanding application for substrate isotropy. Beam steering works by controlling the phase of signals fed to individual array elements. If adjacent elements on the same board experience different Dk values due to material anisotropy, the resulting phase errors corrupt the beam. CuClad 218’s cross-plied construction — providing verified XY isotropy — directly addresses this failure mode. It’s not a theoretical advantage; it’s a practical design enabler for high-performance phased arrays.

Microwave Filters, Couplers, and LNAs

Filters, directional couplers, and low-noise amplifiers (LNAs) all depend on precise impedance control across their operating bandwidth. The combination of stable Dk across frequency and ultra-low loss tangent makes CuClad 218 highly suited to these components. For LNA designs operating at X-band (8–12 GHz), Ku-band (12–18 GHz), and K-band (18–27 GHz), CuClad 218’s loss performance directly translates to lower noise figure — the primary performance metric for these circuits.

Satellite and Space Electronics

Low outgassing is a critical requirement for space applications. CuClad 218’s compliance with NASA SP-R-0022A outgassing standards makes it viable for space electronics, where material outgassing can contaminate optical surfaces or degrade nearby components. Combined with its stable electrical properties across temperature ranges and extremely low moisture absorption, CuClad 218 is well-suited to satellite receiver and payload electronics.

Radomes

CuClad series laminates are specifically called out for radome applications — structural enclosures that house radar antennas and must be electromagnetically transparent. A radome material with Dk near 2.17 introduces minimal phase error to transmitted and received signals. The woven fiberglass reinforcement provides the structural integrity needed for load-bearing radome construction, while the PTFE base ensures low RF insertion loss.

Fabrication Guidelines for Arlon CuClad 218

High-performance material only delivers high performance if the fabrication process treats it correctly. PTFE laminates differ significantly from FR-4 in almost every processing step. Here’s what you and your fabricator need to get right.

Through-Hole Preparation

This is the most critical fabrication step. PTFE is hydrophobic and chemically inert — properties that make it an excellent dielectric but a terrible surface for electroless copper adhesion during plating. Standard through-hole copper plating on untreated PTFE produces no adhesion, resulting in open or intermittent PTH connections that fail immediately or, worse, fail unpredictably in service.

Proper PTFE through-hole preparation requires either sodium etch (chemical activation using sodium/naphthalene solution) or plasma etch (oxygen plasma in a vacuum chamber). Both processes roughen and chemically activate the PTFE drilled-hole surface at a microscopic level, enabling reliable copper adhesion during subsequent electroless plating. Skipping this step is the single most common cause of CuClad 218 PCB failures in fabrication shops without PTFE experience.

Drilling Parameters

PTFE is thermally soft and mechanically compliant compared to FR-4. Drilling requires adjusted parameters — typically lower feed rates and controlled drill speeds — to avoid smearing PTFE material onto the drilled-hole wall (which interferes with subsequent surface activation) and to minimize burring on the exit side. Use hard backup material and entry material appropriate for PTFE drilling. Your fabricator should have verified drill parameter tables for PTFE substrates.

Lamination for Multilayer Designs

For multilayer designs, CuClad 218 requires compatible bonding systems. Standard FR-4 prepregs are not compatible with PTFE-based cores for high-frequency multilayer structures; use Rogers 2929 bondply or equivalent PTFE-compatible bonding materials. For hybrid stackups mixing CuClad 218 with epoxy/glass layers, account for CTE mismatch carefully — the different thermal expansion behaviors of PTFE and glass-epoxy layers must be managed to prevent delamination over thermal cycling.

Surface Finish Selection

Standard finishes — ENIG (electroless nickel immersion gold), immersion silver, OSP — are all compatible with CuClad 218. For designs operating above 10 GHz, pay close attention to surface finish roughness. At these frequencies, conductor loss is significant, and a rough surface finish (such as HASL, which is generally not appropriate for high-frequency PTFE boards) adds unnecessary conductor loss. ENIG and immersion silver offer smoother surfaces and are the preferred choices for mmWave designs.

Decision Framework: Is CuClad 218 Right for Your Project?

Design Requirement	CuClad 218 Fit
Lowest available insertion loss	✅ Excellent
XY plane isotropy (phased arrays)	✅ Excellent
Very low moisture sensitivity	✅ Excellent
Space/low-outgassing application	✅ Excellent
Frequency above 10 GHz	✅ Excellent
Broadband multi-octave circuit	✅ Excellent
Fabricator has PTFE experience	Required
Cost-sensitive commercial design	⚠️ Consider RO4003C or RO4350B
Frequency below 5 GHz	⚠️ Likely overspecified
Mechanically demanding environment	⚠️ Consider CuClad 233 or CuClad 250
Large-volume production	⚠️ Evaluate cost vs. performance trade-off

Useful Resources for Arlon CuClad 218 Design and Procurement

• Rogers CuClad Series Product Page — rogerscorp.com/cuclad-series-laminates — Current product information and Laminate Properties Tool
• Rogers CuClad Datasheet (PDF) — Downloadable from Rogers’ website or authorized distributors; contains Dk vs. frequency and Df vs. frequency curves
• Arlon DiClad/CuClad/IsoClad Fabrication Guidelines — Available from RF Global Net and Rogers’ technical library; essential reading for any fabricator new to CuClad materials
• Matweb — Arlon CuClad 217 Database Entry — matweb.com — Material property listing for CuClad 217/218-class materials; useful for thermal modeling and material comparisons
• Rogers Laminate Properties Tool — Interactive web-based comparison tool across the full Rogers/Arlon laminate portfolio
• Saturn PCB Toolkit — Free impedance calculator supporting PTFE laminate stackups; useful for trace width and signal integrity calculations on CuClad 218
• IPC-4103 Slash Sheet /02 — Industry standard governing woven PTFE-based high-frequency laminates; reference for qualification requirements

Frequently Asked Questions About Arlon CuClad 218

Q1: Is Arlon CuClad 218 still available, and where do I source it?

CuClad 218, as a specific Arlon designation, refers to a variant within the CuClad 217 family (Dk ~2.17–2.20) that Rogers Corporation now manufactures and markets under the Rogers brand. If you have older design documentation specifying “CuClad 218,” contact an authorized Rogers distributor and reference the Dk target (~2.18), required thickness, copper weight, and panel size. Rogers and their distribution network can confirm the exact current product specification that matches your legacy CuClad 218 requirements. Always verify compatibility with your original design specifications before substitution.

Q2: What’s the practical difference between CuClad 218 and RT/duroid 5880 at 18 GHz?

Both materials deliver an almost identical loss tangent (0.0009 at 10 GHz) and very similar dielectric constants (~2.17–2.20 vs. 2.20). The measurable performance difference at 18 GHz is minimal in terms of insertion loss per unit length. Where they differ is in construction and application fit: CuClad 218’s cross-plied woven glass gives verified XY isotropy, critical for phased arrays. RT/duroid 5880’s random microfiber construction is more suited to conformal/curved structures. For flat multi-element arrays, CuClad 218’s isotropy gives it a practical edge. For aerospace structures where the laminate must be formed to shape, RT/duroid 5880 is more appropriate.

Q3: Why is CuClad 218’s Z-axis CTE so high compared to FR-4?

CuClad 218’s z-axis CTE of ~246 ppm/°C looks alarming compared to FR-4 (60–80 ppm/°C below Tg) until you understand the mechanism. PTFE doesn’t have a traditional glass transition temperature in the 50–250°C range — its CTE behavior is dominated by the PTFE itself, not an epoxy glass transition. In practice, this high z-axis CTE requires careful plated through-hole design: keep aspect ratios reasonable (aim for 8:1 or lower), size annular rings generously, and discuss drill-to-copper clearances with your fabricator. A properly designed and processed CuClad 218 PTH can achieve excellent reliability despite the high z-axis CTE.

Q4: Can CuClad 218 be used in hybrid stackups with FR-4 or RO4350B?

Yes, but with important caveats. Hybrid stackups combining CuClad 218 for RF-critical layers with more economical materials for power and signal distribution layers are a common cost-optimization approach. The key challenge is managing CTE mismatch between PTFE-based layers and epoxy-glass or hydrocarbon-ceramic layers. Use PTFE-compatible bonding materials at all interfaces, verify that your fabricator has tested and qualified hybrid constructions before committing to production, and perform thermal cycling qualification testing to confirm reliability. A fabricator with specific hybrid stackup experience is essential for this approach.

Q5: At what frequency range does CuClad 218 justify its cost premium over RO4003C?

This depends on your loss budget, but as a practical guideline: CuClad 218 begins to show clear system-level advantages above about 10 GHz. At 5 GHz and below, the insertion loss difference between Df 0.0009 and Df 0.0027 is small enough in absolute dB terms that the cost of CuClad 218 is rarely justified for commercial applications. At X-band (8–12 GHz) and above, the loss difference grows rapidly with frequency. By Ku-band (12–18 GHz), a system designed on CuClad 218 may show 1–2 dB better insertion loss in key signal paths compared to RO4003C, which in a radar receiver or satellite LNA chain represents a meaningful sensitivity improvement. Military and space applications often justify the cost premium even at lower frequencies, due to reliability and environmental performance requirements.

Summary: When Arlon CuClad 218 Belongs in Your Design

Arlon CuClad 218 occupies a specific and valuable position in the high-frequency laminate landscape. It’s not the easiest material to fabricate, and it carries a cost premium over hydrocarbon-based RF laminates. What it offers in return is a set of electrical properties that simply can’t be replicated in any other woven glass PTFE laminate: the lowest available Dk (~2.17–2.20), a dissipation factor of 0.0009 matched only by the best PTFE composites, true XY isotropy from cross-plied construction, and a moisture absorption so low it effectively eliminates the environment as a performance variable.

For PCB engineers designing military radar, phased array antennas, satellite receivers, precision microwave filters, or any system where the substrate’s electrical properties directly limit system performance at X-band and above, CuClad 218 is one of the materials that belongs on your shortlist. Pair it with a fabricator who genuinely knows PTFE processing, specify the right copper finish for your operating frequency, and design your through-holes for the material’s z-axis CTE — and you’ll have a substrate that delivers on what the datasheet promises.

Arlon CLTE-P is a ceramic-filled PTFE prepreg bonding ply for CLTE multilayer PCBs. This guide covers CLTE-P properties, full datasheet specs, lamination process parameters, and PCB applications in defense radar, phased arrays, and satellite electronics — written for PCB engineers.

Ask most RF PCB engineers what keeps them up at night on a complex multilayer build, and it’s usually not the electrical design — it’s the bonding stack. Getting two PTFE laminate layers to bond reliably, maintain matched dielectric properties, and survive hundreds of thermal cycles without delaminating is genuinely difficult. That’s precisely the problem Arlon CLTE-P was engineered to solve.

This guide breaks down everything you need to know about Arlon CLTE-P: what it actually is, how its properties compare to alternative bonding options, the fabrication parameters your shop needs to get right, and where it fits into real multilayer microwave PCB designs.

What Is Arlon CLTE-P?

Arlon CLTE-P is a prepreg bonding material specifically designed for use in multilayer circuit boards built with PTFE-based microwave printed circuit laminates. More precisely, it is a ceramic-filled PTFE-coated glass stock used as a bonding ply for CLTE, CLTE-XT, and CLTE-AT laminates.

The “P” in CLTE-P simply designates “Prepreg” — it’s the bonding layer member of the broader CLTE product family. Structurally, CLTE-P comprises woven fiberglass fabric coated with a proprietary, ceramic-filled fluoropolymer resin formulation. One critical detail that shapes everything about how you process this material: the proprietary resin is thermoplastic, not thermoset in nature. That distinction has significant implications for press cycle design, temperature management, and sequential lamination strategies, all of which we’ll cover in detail below.

As received from the factory, CLTE-P sheet stock is approximately 0.0032″ thick. After lamination under proper conditions, it compresses to a typical final thickness of around 0.0024″ when properly bonded between flat surfaces. It is supplied in sheeted format.

Why CLTE-P Exists: The PTFE Multilayer Bonding Problem

If you’ve ever tried to bond standard PTFE laminates in a multilayer stack, you know the challenge. PTFE is inherently non-adhesive — it’s the same chemistry that makes cookware non-stick. Getting two PTFE-based layers to bond reliably requires either aggressive surface modification or a bonding material that’s chemically and mechanically compatible with PTFE.

Generic thermoplastic bond films like CuClad 6700 or 6250 work in many PTFE multilayer applications, but they introduce a new problem: the bonding ply has different dielectric properties from the core laminates. In a controlled-impedance stripline design, that bondline sits right in your transmission line stack. If the prepreg Dk doesn’t match your laminate Dk, your impedance calculations are off, and your EM simulator results won’t match reality.

Arlon engineered CLTE-P specifically to solve this. The ceramic-filled fluoropolymer resin formulation is matched in Dk to the CLTE-XT and CLTE laminates. That means the bondline in your multilayer stack doesn’t create a dielectric discontinuity — it’s electrically invisible to your transmission lines. For phased array feed networks and radar manifolds where every fraction of a degree of phase matters, that matching is not a nice-to-have feature, it’s a requirement.

Arlon CLTE-P Key Properties and Datasheet Summary

Understanding the core properties of CLTE-P helps you make informed decisions about stack-up construction and fabrication parameters.

Physical and Dimensional Properties

Property	Value
Construction	Woven fiberglass fabric, ceramic-filled fluoropolymer resin
Resin Type	Thermoplastic (not thermoset)
As-received thickness	~0.0032″
Post-lamination thickness	~0.0024″ (between flat surfaces)
Supply format	Sheeted panels
Melt temperature	510°F (265°C)

Electrical Properties

Property	Value
Dielectric Constant (Dk)	Matched to CLTE / CLTE-XT laminates (~2.94–2.98)
Dissipation Factor (Df)	Low (consistent with CLTE laminate family)
Dk stability vs. temperature	Excellent — suppresses 19°C PTFE phase transition effect
Dk stability vs. frequency	Stable across RF/microwave range

Bonding and Process Properties

Property	Value
Lamination temperature	550°F–572°F (288–300°C) at bond line
Press pressure	400 psi (hydraulic) / 200 psi (vacuum assist)
Maximum copper weight	½ oz (not recommended above this)
Compatible laminates	CLTE, CLTE-XT, CLTE-AT, CLTE-LC
Sequential lamination	Enabled when followed with lower melt temperature bonding films

The melt temperature of 510°F (265°C) is the key process threshold. At this temperature, the thermoplastic resin softens, flows into surface features and copper tooth profiles, and forms a mechanical and chemical bond with the PTFE laminate surfaces. Below this temperature, you won’t get sufficient flow. Above it, you risk uncontrolled resin squeeze-out.

How CLTE-P Fits Into the CLTE Product Ecosystem

CLTE-P doesn’t stand alone — it’s specifically designed as the bonding layer companion to the CLTE laminate family. Here’s how it maps:

CLTE Family Member	Role	Notes
CLTE	Core laminate	Dk 2.98, standard defense/satellite microwave
CLTE-XT	Core laminate (premium)	Dk ~2.94, lowest loss in class
CLTE-AT	Core laminate (commercial)	Dk 3.00, automotive radar, cost-optimized
CLTE-LC	Core laminate (low cost)	Dk 2.94, budget-conscious applications
CLTE-P	Prepreg bonding ply	Bonds all CLTE family laminates in multilayer stacks

The design philosophy is that CLTE-P replicates the mechanical and electrical properties of the CLTE laminates it bonds together. This is what enables consistent, predictable performance through the entire multilayer stack — not just at the laminate layers but also through the bondlines.

CLTE-P prepreg is available to match the stable electrical and mechanical performance characteristics of CLTE-LC laminates as well, confirming that CLTE-P is explicitly designed to be the system-level bonding solution across the full CLTE family.

CLTE-P Fabrication Guidelines: What Your Shop Needs to Know

This is where a lot of engineers get tripped up. CLTE-P is not processed like standard epoxy prepreg. Its thermoplastic nature and high processing temperatures require specific equipment and process controls. Get these wrong and you’ll get poor bond strength, resin starvation, or delamination.

Storage and Handling

Store CLTE-P flat in a cool, dry area away from direct sunlight. Avoid contamination of the copper surfaces — oxidation or particulate contamination at the bondline is a leading cause of adhesion failures in PTFE multilayer boards. Keep the material in its original packaging after opening and use it promptly once opened.

Unlike moisture-sensitive thermoset prepregs, CLTE-P’s thermoplastic resin system is less susceptible to moisture pickup, but best practice is still to bake inner layer material in an air-circulating oven for up to one hour at 225°–250°F (110°–120°C) immediately before lay-up to ensure complete dryness before pressing.

Surface Preparation

This is the step that separates successful PTFE multilayer lamination from failed ones. PTFE surfaces are naturally non-wetting — for CLTE-P to bond properly to the PTFE laminate surfaces, those surfaces need to be activated.

Adhesion to PTFE surfaces can be enhanced by the use of an inert gas plasma or sodium etch process. It is best to laminate as soon as possible after copper etching, since the PTFE surface retains the morphology of the copper (which aids mechanical interlocking) for only a few hours after etch. If you etch a panel in the morning and don’t press it until the next day, you’ve lost a significant portion of your bondline adhesion advantage.

For copper surfaces, adhesion can be improved with an aggressive micro-etch such as ammonium persulfate prior to bonding. Standard Black Oxide or Brown Oxide copper treatment processes are not recommended due to the high temperatures reached during the CLTE-P bonding process — these oxide layers can degrade or cause quality issues at the bondline under high-temperature pressing.

Lamination Press Cycle

The press cycle for CLTE-P is where most fabrication shops need the most process development. The key parameters:

Equipment: A press with heat and cool cycles in the same opening is strongly recommended. This ensures that constant pressure can be maintained throughout both the heat-up and cool-down cycle. Since CLTE-P is a thermoplastic, it will re-soften if pressure is removed before it cools below the melt point — which means a press that opens while still hot will give you a failed bond.

Temperature: CLTE-P requires a lamination temperature of 550°F–572°F (288–300°C) to allow sufficient flow of the resin. The lamination temperature should be measured at the bond line using a thermocouple located in the edge of the product panel — not at the press platens. Due to thermal mass, there can be significant temperature lag between the platen surface and the panel bond line, especially in thick stackups.

Pressure: A pressure of 400 psi (hydraulic press) is recommended to remove any entrapped air and force the flow of the prepreg into the exposed copper surface features. For vacuum-assist presses, 200 psi actual is typically sufficient. This pressure must be maintained throughout the full extent of the heating and cooling cycles.

Heat-up and cool-down rates: Since CLTE-P is a thermoplastic material, precise control of heat-up and cool-down rates is critical. Too rapid a heat-up and you risk thermal gradients causing non-uniform flow. Too rapid a cool-down and you can induce internal stresses in the panel.

Peripheral materials: Because of the high temperatures required for lamination, noncombustible peripheral materials such as separator sheets and press padding must be used. Epoxy separator sheets are not recommended — they may char or burn at CLTE-P lamination temperatures. Paper and certain rubber press padding materials are also incompatible.

The Copper Weight Limitation

One constraint worth flagging explicitly: CLTE-P is not recommended for bonding layers involving more than ½ oz copper. Heavier copper creates surface topography that CLTE-P’s thin resin system (0.0024″ post-compression) cannot adequately fill — you’ll end up with voids at the bondline adjacent to copper features. If your design requires heavier copper inner layers, consider thicker bonding systems or consult Arlon’s application engineering.

Sequential Lamination with CLTE-P

One of CLTE-P’s valuable process features is that it enables sequential lamination — building up a multilayer board in multiple press cycles. Because CLTE-P is thermoplastic with a melt temperature of 510°F (265°C), subsequent press cycles using bonding films with lower melt temperatures will not re-activate the CLTE-P bond lines already formed in earlier cycles. This makes sequential lamination of complex multilayer PTFE stacks achievable without re-melting and disturbing earlier bond layers.

Comparing CLTE-P to Other PTFE Bonding Options

Engineers working with CLTE family laminates have several bonding ply options. Understanding the tradeoffs helps you pick the right one for your build:

Bonding Option	Type	Dk Match	Sequential Lamination	Process Cost
CLTE-P	Thermoplastic prepreg	Excellent (matched to CLTE)	Yes (with lower Tm films below)	Moderate
CuClad 6700	Thermoplastic film	Good	Yes	Low–moderate
CuClad 6250	Thermoplastic film	Good	Yes	Low–moderate
GenClad 280	Hybrid thermoplastic/thermoset	Compatible with PTFE systems	Yes (thermoset capability)	Moderate

CLTE-P is the right choice when Dk matching to your laminate is non-negotiable — defense radar, phased array feed networks, satellite electronics. GenClad 280 is Arlon’s alternative for fabricators who want a thermoset-capable bond ply that avoids the extreme lamination temperatures of pure PTFE prepregs. It provides electrical performance compatible with current PTFE-based composites while delivering process cost closer to traditional PWB materials.

PCB Applications Where Arlon CLTE-P Is the Right Call

CLTE-P exists to enable one thing: reliable, electrically transparent multilayer construction with CLTE family laminates. That makes it the correct bonding specification for any multilayer design built on CLTE substrates — and those designs tend to appear in specific application areas.

Defense Radar and AESA Systems: High-layer-count radar manifolds for AESA systems are among the most demanding multilayer microwave PCBs built. Layer counts can reach into the tens of layers, and every bondline in the stack contributes to the aggregate phase and impedance response of the feed network. CLTE-P’s Dk matching ensures that stripline transmission lines running through the bondlines see a consistent, predictable dielectric environment.

Phased Array Antenna Feed Networks: Phase-sensitive feed networks require not just consistent laminate properties but consistent bondline properties across the full temperature range. The Arlon CLTE family, including CLTE-P, is engineered to suppress the 19°C phase transition effect in PTFE — which means your phase performance holds stable from below freezing to the upper end of your operating range.

Satellite and Space Electronics: CLTE-P’s very low water absorption (inherited from its fluoropolymer chemistry) makes it appropriate for space applications where outgassing and moisture cycling are design concerns. The full CLTE system, including the CLTE-P prepreg, has documented deployment in satellite hardware including boards with layer counts up to 64.

Communication, Navigation, and Identification (CNI) Systems: Avionics CNI systems often combine multiple RF functions on a single high-layer-count board, requiring consistent impedance and phase performance across wide temperature ranges. CLTE-P provides the bonding system to make those multilayer stacks manufacturable with predictable electrical performance.

For a broader view of Arlon PCB material capabilities including the full range of PTFE, polyimide, and epoxy-based laminates, it helps to understand CLTE-P in the context of Arlon’s complete portfolio.

Useful Resources for Engineers Working with CLTE-P

Resource	Description	Where to Find It
Arlon CLTE-P Datasheet	Official material properties, handling notes	arlonemd.com / rogerscorp.com
Arlon CLTE Fabrication Guidelines	Detailed press cycle, drilling, surface prep for full CLTE family	Available via Arlon sales or cirexx.com
Arlon Microwave & RF Materials Guide	Product comparison across full PTFE/ceramic laminate line	integratedtest.com / arlonemd.com
Rogers CLTE-P Product Page	Rogers-era CLTE-P specs (post-2015 acquisition)	rogerscorp.com/acs/products/1097
MatWeb — Arlon CLTE-P	Material database entry with key properties	matweb.com
UL Prospector — Arlon Materials	Searchable database of all Arlon laminate/prepreg properties	ulprospector.com
IPC-4103 Specification	Industry standard for PTFE-based laminates and prepregs	ipc.org

Always verify you’re working from the most current datasheet revision — Arlon materials transitioned to Rogers Corporation ownership in 2015, and some specifications have been updated since original Arlon publication.

A Note on the Arlon/Rogers Transition

If you’re sourcing CLTE-P today, it’s worth knowing that Rogers Corporation acquired Arlon Circuit Materials and Engineered Silicones in 2015. The CLTE product family, including CLTE-P prepreg, continues to be manufactured and supported under Rogers, but not all historical Arlon materials remain available in the current Rogers catalog. If your BOM calls out historical Arlon part numbers, verify current availability with your Rogers distributor and check whether the Rogers-current part number applies.

Frequently Asked Questions About Arlon CLTE-P

Q1: What laminates is CLTE-P designed to bond?

CLTE-P is specifically designed as the bonding prepreg for the CLTE family of microwave laminates: CLTE (standard), CLTE-XT (premium low-loss), CLTE-AT (commercial grade), and CLTE-LC (low-cost grade). Its ceramic-filled fluoropolymer resin formulation matches the Dk of these laminates, ensuring electrically transparent bondlines in controlled-impedance multilayer stacks.

Q2: Why is CLTE-P a thermoplastic prepreg rather than a thermoset?

Thermoset prepregs are common in standard FR-4 multilayer processing because they cure irreversibly and are easy to handle at room temperature. For PTFE-based materials, thermoset resins don’t always provide the compatibility and Dk matching needed. Arlon’s thermoplastic approach in CLTE-P allows the resin to flow and wet the PTFE laminate surfaces at elevated temperature, then re-solidify as it cools to form a strong, low-loss bond. The thermoplastic nature also enables sequential lamination strategies — subsequent bond cycles using lower melt temperature films won’t re-activate the existing CLTE-P bondlines.

Q3: Can I use standard FR-4 prepreg to bond CLTE laminates instead of CLTE-P?

You can, but it’s generally not recommended for controlled-impedance microwave designs. Standard FR-4 prepreg has a Dk of around 3.9–4.5 depending on resin content — far higher than CLTE laminates at approximately 2.94–2.98. That Dk mismatch creates a dielectric discontinuity at every bondline in your stack, throwing off your impedance calculations and introducing phase errors in transmission lines that pass through the prepreg layer. For defense and satellite RF designs, the cost of a failed system far outweighs any savings from substituting cheaper prepreg.

Q4: What press equipment is required for CLTE-P lamination?

A press capable of maintaining pressure through both heat-up and cool-down cycles is required — the heat and cool cycles must occur in the same press opening. Because CLTE-P is thermoplastic, releasing pressure while the panel is still above the melt temperature (510°F / 265°C) will allow the bondline to re-flow and delaminate. Many standard FR-4 shops use presses that open and cool outside the press — this process will not work for CLTE-P without modification. Verify your fabricator has the correct press equipment before committing to a CLTE-P multilayer design.

Q5: What’s the maximum copper weight I can use with CLTE-P as a bonding ply?

CLTE-P is not recommended for bonding inner layers with copper weights exceeding ½ oz. The compressed bondline thickness of approximately 0.0024″ doesn’t provide sufficient resin volume to fill around heavier copper features, leading to voids at the bondline adjacent to circuit patterns. For designs requiring heavier copper — such as power distribution layers in PA boards — consult Arlon/Rogers application engineering for alternate bonding strategies or supplemental resin flow solutions.

Suggested Meta Description:

Arlon CLTE-P is a ceramic-filled PTFE prepreg bonding ply for CLTE multilayer PCBs. This guide covers CLTE-P properties, full datasheet specs, lamination process parameters, and PCB applications in defense radar, phased arrays, and satellite electronics — written for PCB engineers.

Arlon CLTE-MW is a PTFE/ceramic/glass laminate engineered for 5G and millimeter wave PCB applications. Explore complete specs, loss tangent data, fabrication tips, material comparisons, and FAQs in this PCB engineer’s guide.

If you’ve been hunting for a substrate that can handle 5G millimeter wave frequencies without breaking your budget or your fabrication shop, Arlon CLTE-MW deserves a serious look. As someone who’s spent time evaluating RF laminates for demanding antenna and amplifier designs, I can tell you that getting material selection wrong at mmWave frequencies isn’t just a performance issue — it’s a system failure waiting to happen.

This guide covers everything you need to know about Arlon CLTE-MW: what it’s made of, how its key specs translate to real-world design decisions, where it fits and where it doesn’t, and how it compares to the competition. Whether you’re designing a 28 GHz 5G phased array or a 40 GHz point-to-point link, the information here will help you decide if CLTE-MW belongs in your next build.

What Is Arlon CLTE-MW? Understanding the Material Background

Arlon CLTE-MW is a ceramic-filled, woven glass reinforced PTFE composite laminate originally developed by Arlon Electronic Materials — now part of Rogers Corporation after their acquisition of Arlon LLC. The CLTE series has long been one of Arlon’s flagship microwave laminate families, and the CLTE-MW variant was specifically engineered to address the growing demand for cost-effective, high-performance substrates in 5G and other millimeter wave applications.

The “CLTE” designation stands for Coefficient of Linear Thermal Expansion — a name that reflects the product line’s primary design goal: minimizing dimensional and electrical changes due to temperature variation. The “-MW” suffix indicates its optimization specifically for millimeter wave frequency ranges.

Rogers acquired Arlon in 2015, which means CLTE-MW is now sold under the Rogers Corporation umbrella. However, the Arlon branding and product heritage remain strong in the industry, and engineers continue to refer to these materials as “Arlon CLTE-MW” in their daily work. If you’re working with an Arlon PCB supplier, this context matters for procurement and technical support conversations.

Material Composition: Why PTFE + Ceramic + Spread Glass?

Understanding why Arlon CLTE-MW performs the way it does starts with understanding its three-component material system.

PTFE Base Matrix

Polytetrafluoroethylene (PTFE) is the workhorse of high-frequency laminate systems. Its inherently non-polar molecular structure means it produces almost no dielectric loss, even as frequencies climb into the millimeter wave range. PTFE-based materials have been the substrate of choice for radar, satellite, and defense RF circuits for decades.

The downside of pure PTFE? It’s dimensionally unstable, difficult to process, and thermally soft. Raw PTFE laminates can creep under clamping pressure and require special drilling, through-hole preparation, and bonding procedures. The ceramic and glass additions in Arlon CLTE-MW directly address these weaknesses.

Ceramic Filler Loading

The ceramic powder filler in Arlon CLTE-MW serves multiple critical functions. First, it raises the dielectric constant from PTFE’s baseline of approximately 2.1 to a more useful value near 3.0, which allows for more compact circuit geometries. Second, it improves thermal conductivity significantly compared to unfilled PTFE. Third, and crucially for temperature-sensitive applications, the ceramic filler stabilizes the dielectric constant over temperature — reducing the phase shifts that plague pure PTFE circuits as operating temperatures change.

The “high filler loading” mentioned in CLTE-MW’s design specifications also helps minimize the influence of the glass weave on electromagnetic wave propagation, a phenomenon known as the glass weave effect that becomes increasingly problematic as frequency rises.

Spread Glass Reinforcement

At millimeter wave frequencies above 20 GHz, conventional woven glass reinforcement can cause serious problems. The alternating resin-rich and glass-rich regions of a standard woven fabric create periodic variations in local dielectric constant. At high enough frequencies, these variations act as a diffraction grating, causing signal skew, insertion loss variation, and unwanted radiation.

Arlon CLTE-MW uses spread glass reinforcement — a weaving process that flattens and spreads the glass bundles to create a much more uniform fiber distribution. Combined with the high ceramic filler loading, this dramatically reduces glass weave effects. For PCB designers working above 20 GHz, this is not a minor detail; it’s the difference between a design that measures like a simulation and one that doesn’t.

Arlon CLTE-MW Key Specifications and Properties

Here’s a consolidated view of the material properties that matter most for RF and mmWave PCB design:

Electrical Properties

Property	Value	Condition
Dielectric Constant (Dk)	~3.00	10 GHz
Loss Tangent (Df)	0.0015	10 GHz
Dielectric Strength	630 V/mil	—

Thermal Properties

Property	Value
Z-axis CTE	30 ppm/°C
Thermal Conductivity	0.42 W/(m·K)
Moisture Absorption	0.03%

Mechanical and Fabrication Properties

Property	Value
Available Thicknesses	3 mil, 4 mil, 5 mil, 6 mil, 7 mil, 8 mil, 10 mil (7 options)
Copper Foil Options	Rolled, Reverse Treated ED, Standard ED
Flammability Rating	UL94 V-0

Why These Numbers Matter in Practice

Loss tangent of 0.0015 at 10 GHz is genuinely impressive. For comparison, standard FR-4 runs 0.020 or higher, and even well-regarded hydrocarbon laminates like Rogers RO4350B come in at 0.0037. In a 10-inch signal path at 28 GHz, the difference between 0.0037 and 0.0015 Df can mean 2–3 dB of additional insertion loss — easily the difference between a working system and a failing link budget.

Z-axis CTE of 30 ppm/°C is excellent for plated through-hole (PTH) reliability. Copper expands at roughly 17 ppm/°C. The closer a laminate’s z-axis expansion tracks copper, the less mechanical stress accumulates at barrel-to-pad interfaces during thermal cycling. For boards expected to survive hundreds of thermal cycles — common in automotive, aerospace, and outdoor telecom applications — this matters enormously.

Moisture absorption of 0.03% is one of the lowest values available in any commercial laminate. Water has a dielectric constant of approximately 80. Even trace moisture uptake causes measurable Dk drift, which translates directly into impedance variation and phase error. For outdoor 5G base station antennas or automotive radar modules that see humidity cycling over their lifetime, 0.03% moisture absorption provides excellent long-term electrical stability.

Seven thickness options from 3 to 10 mils directly addresses one of the core challenges in mmWave board design: controlling signal-to-ground spacing. At 28 GHz and above, dielectric thickness drives impedance, conductor loss, and surface wave behavior. Having ultra-thin options down to 3 mils gives designers the flexibility to hit characteristic impedance targets on very narrow trace widths without needing excessive stack-up compensations.

Arlon CLTE-MW vs. Competing Materials: Where Does It Fit?

PCB material selection is always a trade-off exercise. Here’s how Arlon CLTE-MW stacks up against the alternatives you’re most likely to encounter:

Arlon CLTE-MW vs. Rogers RO4350B

Parameter	Arlon CLTE-MW	Rogers RO4350B
Dielectric Constant	~3.00	3.48
Loss Tangent (10 GHz)	0.0015	0.0037
Z-axis CTE	30 ppm/°C	32 ppm/°C
Moisture Absorption	0.03%	0.06%
Processing	PTFE-specialized	FR-4 compatible
Typical Cost	Higher	Moderate

RO4350B is arguably the most popular high-frequency laminate on the market because it processes like FR-4. If your fab has no PTFE experience, RO4350B is the safer production choice. But at 28 GHz and above, the 2.5x difference in loss tangent between RO4350B and CLTE-MW starts showing up clearly in system-level performance, particularly in antenna efficiency and amplifier gain.

Arlon CLTE-MW vs. Arlon CLTE-XT

The CLTE-XT is Arlon’s premium option within the CLTE family. It achieves even lower loss (Df around 0.0012), lower moisture absorption, tighter Dk and thickness tolerances, and better phase stability vs. temperature than CLTE-MW. If you’re building a temperature-sensitive phased array radar or a space-grade communications module, CLTE-XT is worth the cost premium. For most commercial 5G applications where cost efficiency matters and the moderate temperature range is acceptable, CLTE-MW hits a better price-performance point.

Arlon CLTE-MW vs. Rogers RT/duroid 5880

RT/duroid 5880 is a PTFE/glass composite with a Dk of 2.2 and an exceptionally low Df of 0.0009 — the benchmark for ultra-low-loss mmWave applications. It’s widely used in radar front ends and satellite receiver chains where insertion loss is critical. CLTE-MW’s higher dielectric constant (3.0 vs. 2.2) allows for more compact circuitry, while RT/duroid 5880 offers lower absolute loss. For very wide-band antennas or highest-sensitivity receiver designs, RT/duroid 5880 wins on raw loss performance. For compact modules where size constraints are real, CLTE-MW’s higher Dk provides useful design flexibility.

Target Applications for Arlon CLTE-MW

Arlon CLTE-MW was designed with a specific set of applications in mind, and it genuinely excels in these environments:

5G Millimeter Wave Infrastructure

The 5G NR FR2 bands (24.25–52.6 GHz) place extreme demands on substrate materials. Tight Dk tolerances, low loss, and physical thickness options that enable proper signal-to-ground spacing make Arlon CLTE-MW a natural fit for 5G mmWave antenna modules, massive MIMO arrays, and beamforming front-end circuits. The spread glass reinforcement is particularly relevant here — phase coherence across an antenna array depends on identical electrical path lengths, and glass weave effects are a real source of inter-element phase error.

Radar Systems (Automotive and Defense)

Automotive radar operating at 77–79 GHz for ADAS applications, and defense radar at various mmWave bands, both benefit from CLTE-MW’s combination of low loss, low moisture absorption, and excellent dimensional stability. The 30 ppm/°C z-axis CTE is critical for multilayer radar modules that must survive the thermal extremes of under-hood automotive environments (-40°C to +125°C).

Amplifiers and Active Components

Power amplifiers and low-noise amplifiers (LNAs) benefit directly from low-loss substrates. Every 0.1 dB of substrate insertion loss is 0.1 dB of added noise figure in a receive chain or 0.1 dB of lost output power in a transmit path. For designs where thermal management is also a concern — which describes most power amplifier applications — CLTE-MW’s thermal conductivity of 0.42 W/(m·K) helps move heat away from active devices more effectively than lower-conductivity PTFE alternatives.

Antennas, Baluns, Couplers, and Filters

These passive components all benefit from stable Dk, low loss, and predictable dimensional behavior over temperature. Antenna designs are particularly sensitive to Dk variation because it directly affects resonant frequency. A patch antenna designed for 28 GHz on a substrate whose Dk drifts with temperature will shift in resonant frequency as the environment changes — not acceptable behavior in a production system. CLTE-MW’s temperature-stable dielectric constant helps these designs perform consistently in the field.

PCB Fabrication Considerations for Arlon CLTE-MW

PTFE-based laminates require different handling and processing than epoxy/glass substrates. Before sending a CLTE-MW design to your PCB fabricator, make sure they have verified experience with the following process steps:

Drilling and Through-Hole Preparation

PTFE is soft and tends to smear during drilling, creating a non-conductive PTFE film on the drilled hole wall that prevents copper adhesion during electroless plating. Proper through-hole preparation requires a sodium or plasma etch step to chemically activate the PTFE surface. Skipping this step results in unreliable or absent plated through-hole copper and dramatic reliability failures in the field.

Copper Foil Selection

CLTE-MW supports three copper foil options: rolled (RA) copper, reverse treated ED copper, and standard ED copper. For high-frequency signal layers, rolled or reverse-treated ED copper offers lower surface roughness, which directly reduces conductor loss at high frequencies. At 28 GHz, skin depth in copper is approximately 0.4 μm — comparable to the surface roughness of standard ED copper. Rough surface copper can add 20–40% additional conductor loss compared to smooth copper at these frequencies. This is not an area to compromise on for mmWave designs.

Dimensional Stability and Registration

PTFE laminates have higher thermal expansion than glass/epoxy boards in the x-y plane. For multilayer designs, accurate layer-to-layer registration requires attention to lamination parameters and careful design of the board’s panel tooling system. Discuss expected shrinkage compensation factors with your fabricator before finalizing your design data.

Hybrid Stackups

It’s common in real-world designs to use CLTE-MW for the critical RF signal layers while using lower-cost materials for DC power distribution and digital control layers. These hybrid stackups can provide excellent system-level cost optimization. However, the CTE mismatch between PTFE-based layers and epoxy-glass layers must be managed carefully to avoid delamination during thermal cycling. Work with a fabricator who has tested and qualified hybrid stackup designs before committing to production.

Material Selection Decision Framework

Use this quick-reference table to help decide whether Arlon CLTE-MW fits your project:

Design Requirement	CLTE-MW Fit
Frequency above 20 GHz	✅ Excellent
Very low insertion loss required	✅ Excellent
Tight impedance tolerance needed	✅ Excellent
Moisture exposure expected	✅ Excellent
PTFE fabrication capability at fab	Required
Budget-constrained project	⚠️ Consider RO4350B
Extreme phase stability needed	⚠️ Consider CLTE-XT
Frequency below 10 GHz	⚠️ Overspecified
Large volume, cost-sensitive	⚠️ Evaluate alternatives

Useful Resources for Arlon CLTE-MW Design and Procurement

These references will be useful as you move from material selection into detailed design and procurement:

• Rogers Corporation CLTE-MW Product Page — rogerscorp.com/clte-mw-laminates — Includes the Laminate Properties Tool for detailed, filterable specification data
• Rogers Laminate Properties Tool — Interactive database for comparing materials across key electrical, thermal, and mechanical parameters
• IPC-4103 Specification — The industry standard governing PTFE-based high-frequency laminate materials; useful for understanding qualification requirements
• Arlon/Rogers Microwave Materials Design Guide — Available from authorized Rogers distributors; covers fabrication guidelines for PTFE laminates in detail
• Saturn PCB Toolkit — Free impedance calculator that supports PTFE laminate stack-up analysis, useful for trace width and impedance target calculations
• Matweb Material Database — matweb.com — Includes Arlon CLTE material property listings useful for cross-reference and thermal modeling
• Everything RF CLTE-MW Listing — Parametric search and distributor sourcing for CLTE-MW materials

Frequently Asked Questions About Arlon CLTE-MW

Q1: Is Arlon CLTE-MW the same as Rogers CLTE-MW?

Yes. Rogers Corporation acquired Arlon LLC in 2015. CLTE-MW was originally developed and marketed by Arlon but is now manufactured and distributed by Rogers Corporation. The product specifications and performance characteristics are the same material. In practice, engineers and procurement teams still commonly refer to it as “Arlon CLTE-MW,” and it’s sold under the Rogers brand. When sourcing the material, search for both “Arlon CLTE-MW” and “Rogers CLTE-MW” to ensure full distributor coverage.

Q2: Can I process Arlon CLTE-MW on a standard FR-4 PCB production line?

Not directly. PTFE-based laminates require specialized through-hole preparation (plasma or sodium etch activation), different drill parameters, and modified lamination procedures compared to FR-4 processing. Using a fabricator without PTFE experience will result in PTH reliability failures and potentially delamination. Always verify that your PCB manufacturer has documented experience processing PTFE laminates before committing a CLTE-MW design to production.

Q3: What is the maximum operating frequency for Arlon CLTE-MW?

Rogers characterizes CLTE-MW for use up to approximately 40 GHz based on its material properties. In practice, engineers have used it in designs operating beyond 40 GHz, but beyond this range, careful full-wave simulation and physical testing are essential. The spread glass reinforcement helps maintain consistent electrical behavior at higher frequencies, but substrate and conductor loss accumulate rapidly above 40 GHz and need to be verified against your system link budget.

Q4: How does moisture absorption of 0.03% affect long-term performance?

Water has a dramatically higher dielectric constant (~80) than most PCB substrates. Even small amounts of absorbed moisture shift the effective Dk of a laminate, which causes impedance variations and phase errors in precision RF circuits. CLTE-MW’s 0.03% moisture absorption is among the lowest available in any commercial laminate. For a 3-mil-thick substrate, this corresponds to an extremely small absolute volume of water uptake, resulting in negligible Dk shift over the material’s operating life. This makes CLTE-MW well-suited for outdoor, marine, or humid industrial environments.

Q5: What copper foil type should I specify for 28 GHz designs on CLTE-MW?

For designs operating at 28 GHz and above, specify reverse treated ED (RTED) or rolled annealed (RA) copper whenever possible. At these frequencies, skin depth is on the order of surface roughness for standard ED copper, meaning conductor loss increases significantly with rough surfaces. Reverse treated and rolled copper foils offer meaningfully lower surface roughness, reducing conductor loss by 20–40% compared to standard ED copper at mmWave frequencies. This is one of the most impactful low-cost design improvements available in high-frequency PCB design.

Summary: When Arlon CLTE-MW Makes Sense

Arlon CLTE-MW occupies a well-defined and genuinely useful position in the RF laminate landscape. It’s not the cheapest material, and it’s not the absolute lowest-loss option available. What it is, however, is a well-engineered balance of very low loss, excellent dimensional stability, superb moisture resistance, ultra-thin thickness options, and spread glass reinforcement that directly addresses the real failure modes of mmWave board designs.

For engineers building 5G millimeter wave antennas, automotive radar modules, defense radar front ends, or satellite communication hardware — especially designs where physical thickness constraints drive the substrate selection — Arlon CLTE-MW deserves a place on your shortlist. Pair it with a fabricator who knows how to process PTFE laminates correctly, specify the right copper foil for your frequency range, and you have a substrate system capable of supporting some of the most demanding RF designs in production today.

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