Arlon CLTE laminate is a ceramic/PTFE composite substrate engineered for low thermal expansion and stable Dk in high-reliability PCBs. Learn key specs, CLTE vs CLTE-XT comparison, fabrication tips, and applications in radar, phased arrays, and satellite electronics — written for working PCB engineers.

If you’ve been designing high-frequency boards long enough, you’ve probably run into the same problem I have — you spec a substrate, build your phased array antenna or radar manifold, push it through thermal cycling, and then watch plated-through holes crack or impedance drift throw off your phase response. That’s usually the moment you start looking seriously at Arlon CLTE laminate.

This guide covers everything a working PCB engineer needs to know: what CLTE actually is under the hood, why its coefficient of thermal expansion (CTE) matters so much for high-reliability builds, how it compares to the broader CLTE family, and where it genuinely earns its premium cost versus where you might be overspecifying.

What Is Arlon CLTE Laminate?

Arlon CLTE laminate is a ceramic powder-filled, woven micro-fiberglass reinforced PTFE composite engineered specifically for microwave and RF printed circuit board applications. The acronym “CLTE” stands for Controlled Low Thermal Expansion — and that name tells you exactly what problem it was designed to solve.

CLTE is a ceramic powder-filled and woven micro fiberglass reinforced PTFE composite engineered to produce a stable, low water absorption laminate with a nominal Dielectric Constant of 2.98. Arlon’s proprietary formulation creates a reduced Z-direction thermal expansion nearer to the expansion rate of copper metal, improving plated-through hole reliability.

The physics behind this are straightforward. Copper expands at roughly 17 ppm/°C in the Z direction. Standard PTFE-based laminates without ceramic loading can run 150–250 ppm/°C in Z — orders of magnitude higher. Every time your board goes through a reflow oven or a thermal cycle in the field, that mismatch puts enormous stress on your vias. Eventually, something gives.

Arlon’s approach to solving this was to load the PTFE matrix with a proprietary ceramic powder filler. The ceramic constrains the natural thermal expansion of the PTFE, pulling the Z-axis CTE dramatically closer to copper. The woven micro-fiberglass reinforcement adds dimensional stability in X and Y. The result is a substrate that behaves far more predictably across temperature extremes than you’d get from an unreinforced PTFE material.

Why Low CTE Matters for High-Reliability PCB Design

Before diving deeper into CLTE’s specs, it’s worth spending a moment on why Z-axis CTE is the critical variable in high-reliability designs. Engineers new to RF laminates sometimes focus exclusively on Dk and Df — and those do matter — but CTE mismatch is often the failure mode that actually kills boards in the field.

When a PCB heats up, the laminate expands. If that expansion rate differs significantly from copper, the barrel of each plated-through hole (PTH) gets stretched. Over thousands of thermal cycles — think aerospace hardware operating across a −55°C to +125°C range — micro-cracks form in the copper barrel. Resistance climbs. Eventually you get an open. In a radar manifold or phased array feed network, that’s a catastrophic failure.

A filled PTFE product such as Arlon’s CLTE-XT does not have a Tg in the range of 50 to 260°C (PTFE does not exhibit a glass transition such as is seen in thermoset materials), but because of the low expansion filler, has a low and consistent Z-direction expansion in that range, by virtue of which it will have excellent plated-through hole reliability.

That’s the core value proposition: matched CTE in Z, excellent PTH reliability, stable electrical performance across the temperature range your system actually operates in.

Arlon CLTE Core Properties and Specifications

Here’s what the datasheet tells you, organized for quick reference:

Electrical Properties

Property	Typical Value	Test Condition
Dielectric Constant (Dk)	2.98	10 GHz
Dissipation Factor (Df)	0.0016–0.0020	10 GHz
TCDk (Temperature Coefficient of Dk)	Very low	Across operating range
Dielectric Constant Stability	Thermally stable	Minimized 19°C phase transition effect

Thermal and Mechanical Properties

Property	Typical Value
Z-axis CTE	Matched nearer to copper (~17 ppm/°C range)
Thermal Conductivity	Higher than standard PTFE laminates
Water Absorption	Very low
Dimensional Stability	Excellent (woven glass reinforcement)

One detail worth highlighting: the formulation was chosen to minimize the change in εr caused by the 19°C second-order phase transition in the molecular structure. This temperature-stable εr simplifies circuit design and optimizes circuit performance in applications such as phased array antennas.

That 19°C transition is a known headache with pure PTFE. Below that temperature, PTFE crystals rearrange, causing a step change in dielectric constant that throws off phase and impedance. The ceramic fill in CLTE suppresses this transition effect significantly — which is why CLTE is a much better choice than plain PTFE when your system needs to operate across the full −55 to +125°C range.

The CLTE Product Family: Choosing the Right Grade

Arlon has developed several variants around the core CLTE platform. Knowing the differences helps you specify the right grade without overpaying.

CLTE (Standard)

The base product. Ceramic/PTFE composite with woven micro-fiberglass reinforcement, Dk of 2.98, good thermal conductivity, low Df, stable Dk vs temperature. The right choice for most defense and satellite microwave applications where you need proven, reliable performance without the tightest possible tolerances.

CLTE-XT (Extended — Premium Grade)

CLTE-XT has “Best-in-Class” Insertion Loss (S21) and Loss Tangent (0.0012). During development, Arlon focused not only on reducing Loss Tangent, but also on reducing Conductive Losses. As a result, CLTE-XT Insertion Loss is “Best-In-Class”.

CLTE-XT tightens Dk tolerance to ±0.03 and delivers the lowest insertion loss in its class. CLTE-XT has the lowest loss, lowest thermal expansion, highest phase stability, and lowest moisture absorption of any product in its class. Use this when you’re building phase-sensitive filter applications, SIGINT electronics, or anything where you need maximum phase stability and the narrowest possible Dk tolerance.

CLTE-AT (Affordable Tier)

CLTE-AT laminates use the common building blocks developed with CLTE-XT laminates, but with some changes to make the product more affordable. This results in a higher dielectric constant (3.00) and a slightly different thickness than the CLTE-XT laminates. CLTE-AT is a solid choice for automotive radar and adaptive cruise control applications — high-volume, cost-sensitive, but still requiring good CTE performance and phase stability.

CLTE-LC (Low Cost)

Arlon’s CLTE-LC is a ceramic-filled, woven fiberglass reinforced PTFE composite engineered to produce a dimensionally and electrically stable, low water absorption laminate with a nominal dielectric constant of 2.94. It is designed to offer all of the same properties and functionality as Arlon’s CLTE, but in most cases at a reduced cost. If your application fits CLTE but budget is a constraint, CLTE-LC is worth evaluating.

Quick Comparison Table

Grade	Dk (10 GHz)	Df	Dk Tolerance	Best For
CLTE	2.98	~0.0016–0.0020	±0.05	Radar, satellite, defense microwave
CLTE-XT	2.94	0.0012	±0.03	Phase-sensitive, SIGINT, space
CLTE-AT	3.00	0.0013	±0.04	Automotive radar, commercial RF
CLTE-LC	2.94	~0.0016–0.0020	±0.05	Cost-sensitive defense/commercial

Key Applications for Arlon CLTE Laminate

Typical applications include radar manifolds, phased array antennas, microwave feed networks, phase-sensitive electrical structures, PAs, LNAs, LNBs, and satellite and space electronics.

Let me break down why CLTE is specifically well-suited for each of these:

Phased Array Antennas

This is probably the most common application you’ll encounter. Phased arrays rely on precise phase control across many radiating elements. Any Dk variation with temperature translates directly to phase error. The temperature-stable εr simplifies circuit design and optimizes circuit performance in applications such as phased array antennas. With CLTE, your Dk stays consistent whether the array is sitting on a cold ramp in Alaska or running hot in the Middle East.

Radar Manifolds

Radar front ends — especially AESA (Active Electronically Scanned Array) radar — use complex power distribution manifolds where every millimeter of trace length contributes to phase and amplitude balance. Dimensional stability of the substrate matters enormously. CLTE’s low X-Y CTE and woven glass reinforcement keep feature dimensions tight across the manufacturing process and across temperature.

Satellite and Space Electronics

CLTE can be made into 64 layers at most on global communication satellites. The combination of low water absorption, stable Dk vs temperature, excellent PTH reliability, and high thermal conductivity makes CLTE a natural fit for space-qualified electronics. In the vacuum of orbit, outgassing and moisture retention are real concerns — CLTE’s low moisture absorption addresses these directly.

Microwave Feed Networks

Combiner/divider networks, beam-forming networks, and corporate feed structures for antenna arrays benefit from CLTE’s consistent impedance across temperature. When you’re splitting power across 64 or 128 channels, any impedance mismatch ripples through the whole system as amplitude and phase imbalance.

Power Amplifiers and LNAs

CLTE also provides higher thermal conductivity that increases the rate of heat dissipation and thus permits use of higher power in an otherwise equivalent design. In PA boards especially, heat management is inseparable from electrical performance. CLTE’s improved thermal conductivity gives designers margin they wouldn’t have with standard PTFE.

Fabrication Considerations for CLTE PCBs

CLTE is a PTFE-based material, which means your standard FR-4 shop processes won’t apply without modification. Here are the key fabrication considerations any PCB engineer should know:

Drilling

Ceramic-filled PTFE is harder on drill bits than FR-4. Expect more frequent bit changes, and ensure your board house uses sharp bits and appropriate feed/speed parameters. The ceramic particles accelerate bit wear — a fabricator who doesn’t adjust will give you sloppy holes and poor barrel quality.

Multilayer Lamination

CLTE prepreg (designated CLTE-P) requires elevated lamination temperatures. 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. This is significantly higher than standard epoxy prepreg lamination, and not all press equipment can handle it. Verify your fabricator’s capabilities before designing multilayer CLTE stacks.

Surface Treatment

Unlike FR-4, PTFE-based materials are inherently non-stick. Proper surface activation before copper plating is essential. Most shops use sodium etching or plasma treatment on PTFE surfaces to achieve adequate bond strength. Skipping this step is a recipe for delamination.

Panelization and Routing

PTFE composites machine differently from rigid thermosets. Use carbide tooling, slower feed rates, and consistent coolant/air blast to get clean edges without smearing.

Arlon CLTE vs. Competing Materials

Engineers evaluating CLTE often compare it against Rogers’ RO3003 or RO4003 series. Here’s a practical comparison:

Parameter	Arlon CLTE	Rogers RO3003	Rogers RO4003C
Dk (10 GHz)	2.98	3.00	3.55
Df (10 GHz)	~0.0016–0.0020	0.0010	0.0027
Z-CTE	Very low (near copper)	Low	Moderate
Water Absorption	Very low	Very low	Low
Multilayer capability	Excellent	Good	Good
Max layer count (reported)	Up to 64	Typically fewer	Typically fewer
Relative Cost	Premium	Premium	Moderate

The comparison isn’t always about which material is “better” overall — it’s about which material fits your specific combination of frequency, thermal environment, layer count, and budget. For deep defense applications requiring maximum phase stability and high layer count, CLTE’s proprietary formulation gives it a strong argument. For single/dual layer commercial microwave boards, RO4003C may offer a simpler fabrication path at lower cost.

For a comprehensive overview of Arlon PCB material families beyond CLTE — including polyimide, epoxy, and other PTFE-based products — it’s worth reviewing the full Arlon portfolio to find the right match for your application.

Design Tips for Getting the Most Out of CLTE

A few things from real-world design experience that don’t always make it into datasheets:

Match your stack-up carefully. CLTE prepreg (CLTE-P) is matched in Dk to CLTE laminates. Don’t mix in standard FR-4 prepreg in a CLTE multilayer stack — the Dk discontinuity will wreck your controlled impedance layers.

Account for Dk variation with thickness. Especially on thin substrates (0.005″ and 0.010″), Dk varies with nominal thickness. The CLTE-XT datasheet explicitly lists design Dk values per thickness. Always design from that table rather than assuming the bulk Dk applies uniformly.

Specify copper foil treatment. Rougher copper foils give better peel strength but increase conductor loss at high frequencies — the skin effect causes current to flow in the rough surface features, increasing resistance. Arlon has designed CLTE-XT specifically to achieve good peel strength with smoother copper, preserving insertion loss performance. Specify low-profile copper if your application is loss-sensitive above 10 GHz.

Thermal via strategy. CLTE’s improved thermal conductivity helps, but for PA boards with significant power dissipation, pair it with a thermal via array under your active devices. The improved laminate conductivity complements, rather than replaces, proper thermal management design.

Useful Resources for PCB Engineers Working with CLTE

Resource	What You’ll Find	URL
Arlon CLTE Datasheet	Full electrical, thermal, mechanical specs	arlonemd.com
Arlon Microwave & RF Materials Guide	Comparison across the full PTFE/ceramic product line	Available via Arlon sales
IPC-4103 Slash Sheet	Specification standard for PTFE/ceramic laminates	ipc.org
Arlon Laminate Design Guide	Practical guidance on high-performance laminate selection	arlonemd.com
UL Prospector — Arlon	Material database with property searches	ulprospector.com
Cirexx Arlon Materials Overview	Fabricator’s perspective on CLTE in production	cirexx.com/arlon-materials

Always pull the latest version of the datasheet directly from Arlon or your authorized distributor — properties are revised periodically as formulations are refined.

Real-World Reliability: What CLTE Delivers Over Time

The question engineers actually care about isn’t just what CLTE looks like on a datasheet — it’s whether it holds up over thousands of thermal cycles in the field. The answer, based on decades of deployment in defense and satellite systems, is that it does — when fabricated correctly.

CLTE is stable during subsequent thermal cycling in process, assembly and use. The key phrase there is “when fabricated correctly.” Arlon’s ceramic/PTFE composite relies on proper surface activation, correct lamination temperatures, and appropriate via-filling practices to deliver that long-term reliability. A poorly executed CLTE build will fail just as surely as a cheaply specified one.

For programs requiring long-life electronics — 20-year satellite missions, airborne radar systems with hard MTBF targets — the combination of low Z-CTE and thermally stable Dk makes CLTE a defensible material choice that holds up under design review scrutiny. When your program office asks why you chose a premium laminate, “matched CTE to copper and stable Dk across −55 to +125°C” is an answer that holds up.

Frequently Asked Questions About Arlon CLTE Laminate

Q1: What does the “CLTE” acronym actually stand for?

CLTE stands for Controlled Low Thermal Expansion. The name directly reflects the material’s primary design intent: using ceramic filler in a PTFE matrix to reduce the coefficient of thermal expansion, particularly in the Z direction, bringing it much closer to the expansion rate of copper conductors. This dramatically improves plated-through hole reliability over thermal cycling.

Q2: Can I use standard FR-4 fabrication processes for CLTE boards?

No — not without significant process modifications. PTFE-based materials like CLTE require different surface preparation (plasma or sodium etch for via hole treatment), higher lamination temperatures for prepreg processing (288–300°C vs. ~180°C for standard epoxy prepreg), and more careful drill bit management due to ceramic filler wear. Work with a fabricator who has documented experience with PTFE laminates, not just FR-4.

Q3: What is the difference between CLTE and CLTE-XT?

CLTE-XT is a premium refinement of the base CLTE platform. It offers the lowest loss tangent (0.0012) and tightest Dk tolerance (±0.03) in the family, along with the lowest thermal expansion and highest phase stability. CLTE-XT is optimized for phase-sensitive and SIGINT applications where every fraction of a dB and every degree of phase matters. Standard CLTE is still the right choice for most defense and satellite microwave applications — CLTE-XT is for the most demanding phase-critical systems.

Q4: Is Arlon CLTE suitable for lead-free (RoHS-compliant) assembly?

Yes. CLTE’s low CTE and thermal stability make it suitable for lead-free solder assembly processes, which operate at higher temperatures than tin-lead soldering. The ceramic/PTFE composite maintains its properties through reflow without the delamination risk that higher-CTE materials carry. That said, always verify your specific assembly parameters with Arlon’s fabrication guidelines, particularly for thick multilayer stackups.

Q5: How does CLTE compare to Rogers RO3003 for phased array antenna applications?

Both are ceramic/PTFE composites with very similar Dk values (~3.0) and both are used extensively in phased array hardware. The main differences are in Df (RO3003 is typically slightly lower at 0.0010 vs. CLTE’s ~0.0016–0.0020), multilayer capability (CLTE has a well-documented track record in very high layer count builds, including up to 64 layers in satellite applications), and sourcing/supply chain considerations. For programs requiring U.S.-origin materials and high layer count multilayers, CLTE has strong advantages. For lower layer count boards where insertion loss is the primary driver, RO3003 is a competitive alternative.

Meta Description Suggestion:

Arlon CLTE laminate is a ceramic/PTFE composite substrate engineered for low thermal expansion and stable Dk in high-reliability PCBs. Learn key specs, CLTE vs CLTE-XT comparison, fabrication tips, and applications in radar, phased arrays, and satellite electronics — written for working PCB engineers.

Editorial long version for your content team

Trimmed 157-character version — within Yoast’s green zone

If you’ve been speccing high-frequency PCB materials long enough, you’ve inevitably landed on the Arlon CLTE family. Three variants, similar names, meaningfully different performance profiles. The Arlon CLTE comparison question comes up constantly in RF design forums and application engineering conversations — and the confusion is understandable. All three are woven PTFE composites. All three target microwave and millimeter-wave applications. But each one was engineered with a different priority, and choosing the wrong one can cost you in signal performance, fabrication complexity, or thermal headroom.

This guide cuts through the naming ambiguity. We’ll work through what distinguishes CLTE from CLTE-MW from CLTE-P at the materials chemistry level, how the specs translate into real design tradeoffs, and which application scenarios each variant actually owns. If you’re staring at a stack-up spreadsheet trying to figure out which CLTE goes on your antenna layer, this is the article you need.

What Is the Arlon CLTE Family?

CLTE stands for Controlled Loss PTFE with Epoxy — though in practice the family uses woven PTFE composite construction rather than a traditional epoxy matrix. All three variants share the same foundational architecture: a woven PTFE fabric reinforcement system combined with ceramic or inorganic filler loading to tune the dielectric constant and mechanical stability. The copper cladding is standard electrodeposited or rolled copper depending on the variant and configuration.

The family sits in Arlon’s premium tier, intended for applications where standard FR4 is wholly inadequate and even mid-tier hydrocarbon ceramic materials (like Rogers RO4003C or Arlon’s own LD730) fall short. We’re talking phased array radar, satellite communications, mmWave 5G beamforming hardware, and defense electronics where the frequency, insertion loss, and environmental requirements are all simultaneously demanding.

Understanding where each variant fits requires looking at both what they share and — more importantly — how they diverge. The full Arlon PCB portfolio places the CLTE family at the top of the performance pyramid, and that positioning is justified by the specifications.

Arlon CLTE Comparison: Core Specifications at a Glance

The table below captures the headline specifications for all three CLTE variants. Values are sourced from Arlon’s published datasheets. Always download the current datasheet from arlon-mmc.com before finalizing your design, as Arlon periodically updates characterization data.

Property	CLTE	CLTE-MW	CLTE-P	Test Method
Dielectric Constant (Dk)	2.94 ± 0.05	3.00 ± 0.05	3.00 ± 0.05	IPC-TM-650 2.5.5.5 @ 10 GHz
Dissipation Factor (Df)	0.0016	0.0012	0.0013	IPC-TM-650 2.5.5.5 @ 10 GHz
CTE X/Y (ppm/°C)	16–18	14–16	14–16	IPC-TM-650 2.4.41
CTE Z (ppm/°C)	~100	~24	~24	IPC-TM-650 2.4.41
Moisture Absorption	0.04%	0.04%	0.04%	IPC-TM-650 2.6.2
Thermal Conductivity	0.20 W/m·K	0.23 W/m·K	0.23 W/m·K	—
Peel Strength (1 oz Cu)	>1.0 N/mm	>1.0 N/mm	>1.0 N/mm	IPC-TM-650 2.4.8
Flammability	UL 94 V-0	UL 94 V-0	UL 94 V-0	—
Primary Differentiator	Low Dk baseline	Controlled Z-CTE	Controlled Z-CTE + flex resistance

At first glance the numbers look nearly identical. The real differentiation lives in the CTE Z column and in how each material behaves under different mechanical and thermal stress conditions — which is why an Arlon CLTE comparison based purely on Dk and Df misses the point.

Breaking Down Each Variant

Arlon CLTE: The Baseline High-Performance PTFE

The original CLTE is a woven PTFE composite optimized for the lowest achievable Dk in this family — 2.94 at 10 GHz. The slightly lower Dk compared to CLTE-MW and CLTE-P translates to higher guided wave velocity, which matters for some antenna element spacing calculations and filter designs where physical size is constrained by wavelength.

The Df of 0.0016 is excellent — competitive with Rogers RT/duroid 5880 (Df ~0.0009) at lower frequency, though the gap widens at higher millimeter-wave frequencies. For applications in the 5–30 GHz range, CLTE’s insertion loss performance is strong enough that dielectric loss rarely becomes the dominant loss mechanism in realistic designs.

Where CLTE’s specification stands out less favorably is the CTE Z value of ~100 ppm/°C. This is a characteristic of woven PTFE systems that don’t incorporate specific Z-axis CTE control mechanisms. For a single-layer or double-sided PTFE board with short via barrels, this rarely causes reliability problems. But for thick multilayer constructions with many thermal cycles, the Z-axis expansion mismatch between the CLTE dielectric (100 ppm/°C) and copper-plated through-hole barrels (~17 ppm/°C) creates fatigue stress that can eventually crack via plating. This is the primary reason CLTE-MW was developed.

Best applications for Arlon CLTE:

• Two-layer and simple multilayer microwave circuits up to ~30 GHz
• Microstrip patch antennas and corporate feed networks
• Single-conversion receiver front ends
• Applications where Z-axis CTE is not a reliability concern (thin substrates, short vias)

Arlon CLTE-MW: The Reliable Workhorse for Multilayer Microwave

CLTE-MW adds a critical architectural improvement over the base CLTE: controlled Z-axis CTE. Through modified filler loading and matrix design, Arlon brought the Z-CTE down from ~100 ppm/°C to ~24 ppm/°C — a 4x improvement that dramatically reduces via barrel fatigue stress in multilayer constructions.

The tradeoff for this improvement is a slight increase in Dk (3.00 vs 2.94) — a difference so small it’s within measurement tolerance for most applications. The Df of 0.0012 at 10 GHz is actually slightly better than base CLTE, which reflects the different filler loading chemistry rather than a direct performance compromise.

CLTE-MW is the variant most commonly specified for multilayer phased array antenna boards, radar front-end modules, and satellite payload electronics. The improved Z-CTE makes it suitable for the 50–200 mil thickness range with 30+ mil via barrels that would stress base CLTE over temperature cycling. Military programs that require MIL-PRF-31032 or similar reliability standards almost always specify CLTE-MW (or equivalent) rather than base CLTE specifically because of the via reliability improvement.

The “MW” suffix standing for “microwave” in the sense of the application rather than a frequency-band limitation — CLTE-MW performs well from below 1 GHz through Ka-band (26.5–40 GHz) and is used in some programs pushing toward 60 GHz, though material loss increases meaningfully above ~40 GHz.

Best applications for Arlon CLTE-MW:

• Multilayer radar front-end and antenna PCBs (AESA, PESA)
• Satellite communication payloads (L through Ka-band)
• Defense electronics with thermal cycling reliability requirements
• Any CLTE application where via barrel depth exceeds ~30 mil in a multilayer build
• 5G mmWave beamforming modules (24–40 GHz)

Arlon CLTE-P: When Mechanical Robustness Enters the Equation

CLTE-P adds a third dimension to the CLTE-MW architecture: improved mechanical robustness and resistance to handling damage during fabrication. The “P” designation refers to enhanced properties targeting manufacturability and mechanical performance in addition to the electrical and CTE characteristics already present in CLTE-MW.

The electrical specs for CLTE-P are essentially identical to CLTE-MW — Dk 3.00, Df 0.0013, Z-CTE ~24 ppm/°C. The differentiation shows up in:

• Better resistance to microcracking during drilling, routing, and board depanelization
• Improved surface quality on drilled holes, which reduces plating voids and supports higher-reliability through-hole metallization
• Enhanced laminate toughness that reduces edge chipping and delamination risk during mechanical assembly operations

For programs that require high fabrication yield on expensive, complex multilayer PTFE boards — and where the raw material cost is already high enough that scrap is a significant concern — CLTE-P’s improved manufacturability can justify the slightly higher material cost. This matters most in prototype and low-volume production scenarios where each panel represents a meaningful cost, and in boards with dense via fields or tight routing that push the limits of PTFE drilling.

Best applications for Arlon CLTE-P:

• Complex multilayer builds with high via density on PTFE layers
• Programs where fabrication yield on expensive PTFE panels is a priority
• Designs with tight mechanical tolerances on hole positioning and edge quality
• Applications where both CLTE-MW electrical performance and enhanced mechanical toughness are needed simultaneously

Side-by-Side: Arlon CLTE Comparison Decision Matrix

The table below is a practical quick-reference for the Arlon CLTE comparison decision. It summarizes when each variant is the natural choice versus when you should consider an alternative.

Design Scenario	CLTE	CLTE-MW	CLTE-P
Single/double-layer microwave board	✅ Ideal	✅ Works	✅ Works
Multilayer (>4 layers) with through-holes	⚠️ Via reliability risk	✅ Ideal	✅ Ideal
Thick board (>60 mil) with long via barrels	❌ Not recommended	✅ Ideal	✅ Ideal
Military/aerospace thermal cycling requirement	⚠️ Verify reliability	✅ Preferred	✅ Preferred
High via density, complex routing	⚠️ OK	✅ Good	✅ Best
Maximum insertion loss performance priority	✅ Slightly better Df	✅ Excellent	✅ Excellent
Lowest possible Dk needed	✅ 2.94	⚠️ 3.00	⚠️ 3.00
Budget-sensitive with simple geometry	✅ Lower cost	✅ Mid cost	✅ Higher cost
40 GHz+ operation	✅ OK	✅ OK	✅ OK

How CLTE Variants Compare to Competing Materials

No Arlon CLTE comparison is complete without understanding where the family sits relative to competing materials at a similar performance tier. The table below positions each CLTE variant against the most commonly compared alternatives.

Material	Dk @ 10 GHz	Df @ 10 GHz	Z-CTE (ppm/°C)	Fabrication Complexity	Relative Cost
Arlon CLTE	2.94	0.0016	~100	High (PTFE)	High
Arlon CLTE-MW	3.00	0.0012	~24	High (PTFE)	High
Arlon CLTE-P	3.00	0.0013	~24	High (PTFE)	High
Rogers RT/duroid 5880	2.20	0.0009	237	High (PTFE)	Very High
Rogers RO3003	3.00	0.0010	24	High (PTFE/ceramic)	High
Taconic TLX-0	2.45	0.0010	High	High (PTFE)	High
Isola Astra MT77	3.00	0.0017	~40	Modified FR4	Medium-High
Arlon LD730 (epoxy)	3.00	0.0022	~42	Standard (FR4-like)	Medium

The comparison against Rogers RO3003 is particularly relevant because RO3003 also targets Dk = 3.00 with a low Z-CTE (~24 ppm/°C). RO3003 achieves this through a PTFE/ceramic composite approach rather than woven PTFE. For most multilayer microwave applications, RO3003 and CLTE-MW are genuine competitors — and the choice often comes down to which material your fabricator has already qualified.

Rogers RT/duroid 5880’s Df advantage (0.0009 vs 0.0012 for CLTE-MW) becomes meaningful above ~40 GHz where dielectric loss starts to dominate. Below that, the difference in a typical 6-inch transmission line is fractions of a dB — measurable in a lab, but often lost in the noise of connector and launch variations in real hardware.

Fabrication Considerations for All CLTE Variants

One thing all three CLTE variants share is that they are PTFE-based materials, which means your fabrication partner needs PTFE-specific capabilities. This is non-negotiable and is one of the main reasons engineers sometimes opt for near-equivalent epoxy materials like Arlon LD730 instead. What PTFE fabrication actually requires:

Drilling PTFE Laminates

PTFE is a soft, viscoelastic polymer that behaves very differently from glass-epoxy under a drill bit. Standard FR4 drill parameters will smear PTFE rather than cut it cleanly, resulting in rough hole walls that compromise plating quality. Fabs running PTFE use:

• Lower drill speeds and higher feed rates compared to FR4
• Fresh, sharp bits with higher replacement frequency
• Controlled drill stack heights to maintain bit deflection below spec
• Liquid CO2 cooling in some advanced setups for very fine vias

Surface Preparation for Plating

Standard potassium permanganate desmear chemistry — the workhorse for FR4 via preparation — does not work on PTFE. The PTFE surface must be treated with sodium naphthalene etchant or plasma etch to create the surface activation needed for copper adhesion. This is a process step that requires separate chemistry lines from FR4 work, which is one reason PTFE-capable fabs charge a premium.

Lamination

Woven PTFE materials have lower dimensional stability during lamination than glass-reinforced epoxy systems. This means tighter layer-to-layer registration control is needed, particularly in large-format panels. Ask your fab for their demonstrated registration capability on PTFE multilayer builds before committing to a design with tight via-to-copper clearances.

Practical Resources for Arlon CLTE Design and Specification

The following resources are recommended for engineers working through an Arlon CLTE comparison or designing with any of these materials.

Resource	Description	Link
Arlon CLTE Datasheets (All Variants)	Official specs for CLTE, CLTE-MW, CLTE-P	arlon-mmc.com
IPC-4103 Standard	Qualification and performance specification for high-frequency laminates	ipc.org
IPC-TM-650 Test Methods	Test methods referenced in all Arlon datasheets	ipc.org
Polar Si9000e	Controlled impedance field solver — input CLTE Dk directly	polarinstruments.com
Ansys HFSS	3D EM simulation for antenna and component design on CLTE substrates	ansys.com
Rogers MWI-2010 Calculator	Useful for cross-checking CLTE impedance calculations against similar Dk materials	rogerscorp.com
Saturn PCB Toolkit	Free calculator for transmission lines, vias, and differential pairs	saturnpcb.com
CST Microwave Studio	Alternative 3D EM solver with strong PTFE material libraries	3ds.com

Frequently Asked Questions: Arlon CLTE Comparison

Q1: What is the single most important difference between CLTE and CLTE-MW in a real design?

Z-axis CTE. CLTE’s Z-CTE of ~100 ppm/°C creates significant via barrel fatigue risk in multilayer constructions subjected to thermal cycling. CLTE-MW’s ~24 ppm/°C Z-CTE is close enough to copper’s 17 ppm/°C to survive the thermal cycling profiles required for most military, aerospace, and automotive qualification tests. If your board has any meaningful layer count and through-holes, CLTE-MW is almost always the right choice over base CLTE.

Q2: Can I substitute CLTE-MW for CLTE on an existing design without layout changes?

For most designs, yes — the Dk difference is only 0.06 (2.94 vs 3.00), which translates to a small change in transmission line widths and electrical lengths. For wideband designs or precision filter work, you’d want to re-simulate with the CLTE-MW Dk. For general microwave interconnect and antenna feed networks, the difference is within normal material Dk tolerance anyway. The Df of CLTE-MW (0.0012) is actually slightly better than CLTE (0.0016), so your insertion loss will be marginally improved.

Q3: Is the CLTE family suitable for 77 GHz automotive radar applications?

The CLTE family is viable for 77 GHz work, but dielectric loss increases substantially at W-band frequencies. At 77 GHz, a Df of 0.0012–0.0016 generates measurable insertion loss even over short trace lengths, and the material’s woven reinforcement can introduce anisotropic Dk behavior that complicates antenna calibration. Most serious 77 GHz radar front-end designs use air-filled or suspended substrate configurations, or lower-Dk PTFE materials like Rogers RT/duroid 5880 (Df 0.0009). CLTE variants are more practical for the IF and baseband sections of a hybrid radar module, or for 24 GHz applications.

Q4: How does CLTE-P differ from CLTE-MW if the electrical specs are essentially the same?

CLTE-P’s differentiation is primarily mechanical: better resistance to microcracking during drilling, improved hole wall quality, and reduced edge chipping during routing and depanelization. If you’re fabricating a straightforward multilayer board at normal via densities, CLTE-MW is perfectly adequate and slightly lower cost. CLTE-P becomes the preferred choice when you’re pushing via density limits on expensive PTFE panels, when first-pass fabrication yield is critical (e.g., low-volume aerospace builds where each panel is thousands of dollars), or when your fabricator specifically recommends it for a complex build based on their process experience.

Q5: What PCB fabricators are qualified to run Arlon CLTE materials, and how do I find one?

CLTE variants require PTFE-qualified fabrication capabilities. Not all PCB fabs have this — PTFE processing requires separate chemistry lines and trained operators. Contact Arlon directly through arlon-mmc.com for a list of authorized fabricators with CLTE process experience. For mil-aero programs, your fabricator will also need appropriate ITAR registration and potentially MIL-PRF-31032 or AS9100 certification. In North America, a handful of specialty microwave PCB fabs run CLTE daily; in Asia, PTFE capability is less universal but available at larger shops serving defense export programs.

Choosing the Right CLTE Variant: A Summary

After working through the specifications, fabrication considerations, and application scenarios, the selection logic for the Arlon CLTE comparison resolves into a fairly clear framework.

Start with CLTE-MW as your default choice for any new multilayer microwave or mmWave design. Its combination of Dk 3.00, Df 0.0012, and controlled Z-CTE makes it the most broadly applicable variant in the family for complex PCB constructions. The slight Dk increase over base CLTE is negligible for almost all practical designs, and the reliability improvement for through-hole interconnects in a multilayer build is substantial.

Move to base CLTE only when you have a specific reason: a design with genuinely simple geometry (two layers, few vias, thin substrate) where Z-CTE is not a reliability concern, and where the slightly lower Dk or lower material cost justifies the tradeoff. Some specific filter designs where the 2.94 vs 3.00 Dk shift changes element dimensions in an inconvenient direction also justify base CLTE.

Specify CLTE-P when your fabricator recommends it for a complex build, when you’re designing for very high via density, or when the mechanical toughness improvement is worth the incremental cost on a program where scrap risk is high. CLTE-P is particularly worth considering for prototype and low-rate initial production (LRIP) phases where fabrication yield directly affects program schedule.

All three variants deliver world-class dielectric loss performance for RF and microwave PCB designs. The differentiation between them is about reliability engineering and manufacturability, not fundamental electrical capability. Spec the one that matches the mechanical and thermal demands of your specific build — and make sure your fab has the PTFE processing capability to do it justice.

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Arlon CLTE comparison guide: understand the real differences between CLTE, CLTE-MW, and CLTE-P woven PTFE laminates. Covers dielectric specs, Z-axis CTE, via reliability, fabrication requirements, and application guidance for RF, radar, satellite, and mmWave PCB designers.

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Automotive radar has quietly become one of the most technically demanding PCB substrate problems in commercial electronics. A decade ago, 77 GHz radar was exotic — reserved for high-end luxury vehicles and specialized industrial sensing. Today it’s a standard ADAS feature across mid-range passenger cars, trucks, and increasingly, two-wheelers. As volumes have scaled, so has the pressure to build reliable, cost-effective 77 GHz radar hardware that survives an automotive-grade thermal and mechanical environment for 15+ years.

At 77 GHz, your PCB substrate is no longer just a mechanical carrier for components. It’s an active participant in antenna performance, beam shaping, and insertion loss. The wrong material degrades radar range, distorts beam patterns, and introduces temperature-dependent drift that makes your calibrated system unreliable in the field. Arlon automotive radar PCB materials address this problem directly — offering the combination of low dielectric loss, stable Dk over temperature and frequency, and automotive-grade reliability that 77 GHz ADAS hardware demands.

This guide covers the full picture: why 77 GHz imposes such strict substrate requirements, which Arlon materials are relevant for automotive radar work, how they compare across the properties that matter most, and what practical design and fabrication decisions you need to make before your first prototype.

Why 77 GHz Automotive Radar Is a Uniquely Difficult PCB Problem

Before getting into Arlon-specific materials, it’s worth being explicit about what makes automotive radar substrate selection harder than most other RF PCB applications.

The Frequency Is Unforgiving of Dielectric Loss

At 77 GHz, even a small dissipation factor generates significant insertion loss over short trace lengths. The dielectric loss in a PCB transmission line scales roughly with frequency and Df simultaneously — which means the penalty for using a lossy substrate at 77 GHz is dramatically higher than at 24 GHz or 10 GHz.

To put numbers to this: a typical PTFE-based substrate with Df = 0.0012 might contribute 1–2 dB of dielectric loss per inch at 77 GHz. Standard FR4 at Df = 0.020 would lose 15–25 dB per inch at the same frequency. That’s not a rounding error — it’s the difference between a functioning radar and a dead one. Even mid-tier epoxy RF materials like Rogers RO4003C (Df = 0.0027) show meaningful loss at 77 GHz over anything beyond the shortest interconnects. This is why 77 GHz antenna and feed network layers almost universally require PTFE-based or very-low-loss substrate materials.

Dk Stability Over Temperature Is a Safety Issue

Automotive operating temperatures span roughly -40°C to +125°C under hood, and the PCB substrate sees that full range in normal service. If your substrate’s Dk changes meaningfully over that temperature range, your 77 GHz antenna elements shift resonant frequency, your beam patterns change shape, and your calibrated detection algorithms start producing errors. In an ADAS system with collision avoidance functions, this is not an academic concern — it is a safety issue that AEC-Q and ISO 26262 functional safety frameworks address through material stability requirements.

PTFE-based materials have inherently low Dk temperature coefficient of dielectric constant (TCDk), making them more stable across the automotive temperature range than epoxy-based alternatives. This is one of the primary reasons PTFE composites dominate the 77 GHz antenna layer market.

The Automotive Reliability Envelope Is Demanding

Mil-aero programs get a lot of attention for their environmental requirements, but automotive radar hardware faces a different kind of demanding profile:

• 15+ year service life with minimal maintenance access
• Wide thermal cycling: -40°C to +125°C (or +150°C for some under-hood applications) per AEC-Q200
• High vibration from road surface and engine
• Humidity and condensation for exterior-mounted sensors
• Thermal shock from cold starts in extreme climates followed by rapid heat build-up
• 100% solderless or SMT assembly compatibility — PTFE materials must survive reflow reliably

The substrate material must survive all of this while maintaining electrical performance within calibration tolerance for the life of the vehicle. That’s a meaningful reliability ask on top of the RF performance requirements.

Arlon Automotive Radar PCB Materials: The Relevant Portfolio

Arlon’s product portfolio addresses automotive radar at two distinct levels: the high-frequency antenna and feed network layers (where PTFE is effectively required) and the lower-frequency digital/IF processing layers (where advanced epoxy materials are appropriate). Understanding which Arlon material applies to which layer in your stack is the foundation of good 77 GHz radar PCB design.

CLTE-MW: Arlon’s Core Offering for 77 GHz Antenna Layers

CLTE-MW is the Arlon material that most frequently appears in discussions of Arlon automotive radar PCB design. It is a woven PTFE composite with ceramic filler loading that achieves Dk = 3.00 ± 0.05 and Df = 0.0012 at 10 GHz — with Df remaining in the 0.0015–0.0020 range at 77 GHz depending on frequency and measurement methodology.

The properties that make CLTE-MW relevant for automotive radar:

• Low Df: Minimizes dielectric insertion loss in antenna feed networks and patch arrays
• Controlled Z-CTE (~24 ppm/°C): Critical for via reliability in multilayer hybrid constructions subjected to automotive thermal cycling
• Stable Dk over temperature: PTFE-based chemistry provides low TCDk versus epoxy alternatives
• Tight Dk tolerance (±0.05): Supports accurate antenna element resonance prediction and maintains beam pattern fidelity across vehicles in production

For a 77 GHz patch array antenna — the dominant topology in automotive forward radar — the substrate Dk directly determines the patch dimensions and element spacing for a given operating frequency. A Dk tolerance of ±0.05 at Dk = 3.00 is approximately ±1.7%, which translates to approximately ±130 MHz frequency shift in a 77 GHz patch resonator. Whether that’s acceptable depends on your system bandwidth and link budget, but CLTE-MW’s tolerance is competitive with the best materials in this space.

CLTE-P: The Fabrication Yield-Optimized Option

For high-complexity multilayer automotive radar boards — particularly those with dense via fields connecting the PTFE antenna layers to the underlying IF and digital processing layers — CLTE-P offers the same Dk/Df profile as CLTE-MW but with enhanced mechanical robustness during drilling. In high-volume automotive production where panel utilization and yield directly affect per-unit cost, CLTE-P’s resistance to microcracking during via drilling can meaningfully improve production economics.

The electrical specs (Dk 3.00, Df 0.0013) are essentially identical to CLTE-MW, so there is no RF performance tradeoff for choosing CLTE-P over CLTE-MW in a production-optimized automotive program.

AD250C and AD300D: Lower-Dk Options for Specific Antenna Architectures

Not all 77 GHz antenna designs use a Dk = 3.0 substrate. Some wideband and aperture-coupled patch designs benefit from lower-Dk materials to achieve specific bandwidth, efficiency, or beamwidth targets. AD250C (Dk = 2.50, Df = 0.0015) and AD300D (Dk = 3.00, Df = 0.0020) provide additional material options in Arlon’s portfolio for antenna layers requiring different electrical characteristics.

AD250C is particularly relevant for endfire antenna designs and substrate-integrated waveguide (SIW) structures where the lower Dk reduces guided wave velocity and extends the achievable bandwidth. For most standard patch array automotive radar designs, CLTE-MW or CLTE-P remains the preferred choice, but AD250C deserves evaluation during the antenna design optimization phase.

LD730 and LD621: Arlon Epoxy Materials for IF and Digital Layers

The 77 GHz radar module is not a single-material board. Modern automotive radar typically uses a hybrid stack-up where:

• Top layers: PTFE substrate for the 77 GHz antenna array and feed network
• Middle/bottom layers: Standard or advanced epoxy material for the IF signal chain, baseband processing, power management, and vehicle interface (CAN, Ethernet)

For the epoxy portion of that hybrid stack, Arlon LD730 (Dk = 3.0, Df = 0.0022) and LD621 (Dk = 3.4, Df = 0.0030) are relevant choices — particularly for the IF signal chain which may run at 1–10 GHz intermediate frequencies where standard FR4 is lossy but PTFE is unnecessary.

The LD-series materials also process on standard FR4 equipment, which means the epoxy layers of the hybrid stack can be fabricated with conventional processes while only the PTFE layers require specialized handling. This is a practical advantage that affects both prototype cost and production scalability.

Core Material Properties for 77 GHz Automotive Radar PCB Design

The table below shows the key properties of Arlon materials relevant to automotive radar, organized by their role in the board stack.

Material	Role in Radar PCB	Dk @ 10 GHz	Df @ 10 GHz	Z-CTE (ppm/°C)	Temp Stability	Fab Process
CLTE-MW	77 GHz antenna / feed	3.00 ± 0.05	0.0012	~24	Excellent	PTFE-specialized
CLTE-P	77 GHz antenna / feed	3.00 ± 0.05	0.0013	~24	Excellent	PTFE-specialized
AD250C	Low-Dk antenna layers	2.50 ± 0.05	0.0015	~25	Excellent	PTFE-specialized
AD300D	Wideband antenna feed	3.00 ± 0.05	0.0020	~25	Excellent	PTFE-specialized
LD730	IF / digital layers	3.00 ± 0.05	0.0022	~42	Very Good	FR4-compatible
LD621	IF / digital layers	3.40 ± 0.05	0.0030	~42	Good	FR4-compatible

Arlon Automotive Radar PCB vs Competing Materials

Arlon does not compete in isolation in the automotive radar material space. Rogers, Isola, and Taconic all offer materials targeting this application. The table below positions Arlon’s key radar materials against the most commonly specified alternatives.

Material	Dk @ 77 GHz (approx.)	Df @ 77 GHz (approx.)	Z-CTE (ppm/°C)	Automotive Programs	Notes
Arlon CLTE-MW	~3.05	~0.0018	~24	Growing adoption	Strong Z-CTE control
Rogers RO3003G2	~3.00	~0.0010	~24	Widely used	Industry benchmark
Rogers RT/duroid 5880	~2.22	~0.0013	~237	Limited (Z-CTE)	Low Z-CTE concern in thin builds
Isola Astra MT77	~3.00	~0.0017	~40	Growing	Thermoset, easier processing
Taconic RF-35	~3.50	~0.0018	~37	Some adoption	Higher Dk
Panasonic Megtron 7	~3.30	~0.0015	~37	Strong in Japan/Asia	Thermoset, FR4-compatible

Rogers RO3003G2 is the benchmark material for 77 GHz automotive radar — it has the widest program adoption, the richest simulation model library, and the most documented fab process. Arlon CLTE-MW is a direct competitor in this space, with the advantage of Arlon’s defense program heritage on PTFE composites and competitive pricing in certain volume tiers.

Isola Astra MT77 is an interesting alternative — it’s a thermoset (non-PTFE) material that achieves competitive Dk/Df at 77 GHz with easier fabrication, similar to how the Arlon LD-series challenges PTFE at lower frequencies. For automotive radar volumes where fabrication simplicity reduces cost, thermoset materials like Astra MT77 and Panasonic Megtron 7 are gaining traction.

Hybrid Stack-Up Design for 77 GHz Automotive Radar

Most production 77 GHz radar modules use a hybrid PCB stack-up rather than a homogeneous PTFE construction. Understanding how to construct that hybrid correctly is one of the most practically important topics for an Arlon automotive radar PCB design.

Typical Hybrid Stack-Up Architecture

A representative 6-layer hybrid radar PCB stack might look like this:

Layer	Material	Function
Layer 1 (top)	Arlon CLTE-MW	77 GHz patch antenna array
Layer 2	Arlon CLTE-MW	77 GHz feed network / ground plane
Bondply	RF-compatible prepreg	PTFE-to-epoxy bonding layer
Layer 3	Arlon LD730 or FR4	IF signal chain (1–10 GHz)
Layer 4	Standard prepreg	Ground / power
Layer 5	Standard FR4	Baseband digital / power management
Layer 6 (bottom)	Standard FR4	CAN / Ethernet / connector interface

This construction keeps the expensive PTFE material only where the 77 GHz signals live, while the balance of the board uses lower-cost materials with standard processing. The bonding layer between the PTFE and epoxy sections is critical — standard FR4 prepregs do not bond reliably to PTFE surfaces. Arlon’s AD7068 or compatible PTFE-to-epoxy bondply materials are used at this interface to ensure lamination integrity through the automotive thermal cycling range.

CTE Matching in Hybrid Stacks

The mismatch in Z-axis CTE between PTFE layers (CLTE-MW ~24 ppm/°C) and standard FR4 (~70 ppm/°C) creates stress at the PTFE/epoxy interface during thermal cycling. CLTE-MW’s controlled Z-CTE significantly reduces this mismatch compared to high-Z-CTE PTFE materials, which is one of the reasons it is preferred over RT/duroid 5880 in hybrid automotive constructions. Your fab should have thermal cycling data on their specific PTFE/epoxy hybrid process — request it before committing to a production design.

77 GHz Signal Transition Design

The via transitions between the 77 GHz antenna/feed layers and the IF/digital layers below are among the most critical design elements in a hybrid radar PCB. Poor transition design at 77 GHz generates return loss and mode conversion that degrades antenna efficiency and complicates calibration.

Best practices for via transitions in 77 GHz hybrid stacks:

• Minimize via length in the 77 GHz signal path — use buried or blind vias to reduce the stub length that the 77 GHz signal sees
• Back-drill any through-hole vias on 77 GHz signal nets to remove resonant stubs below the active layer
• Simulate via transitions in a 3D EM tool (HFSS, CST, or similar) — analytical formulas are not accurate at 77 GHz
• Minimize reference plane perforations near 77 GHz transitions to maintain continuous ground return

Design and Simulation Workflow for Arlon Automotive Radar Boards

EM Simulation Is Non-Negotiable at 77 GHz

At this frequency, analytical transmission line models are useful for first-pass estimates but not for final design. The wavelength in CLTE-MW at 77 GHz is approximately 2.2 mm — which means board features that are small fractions of a millimeter (pad geometries, via anti-pad dimensions, conductor edge roughness) affect performance meaningfully. Full 3D electromagnetic simulation with accurate material parameters is mandatory for the antenna array, feed network, and all 77 GHz transitions.

Key simulation workflow steps:

• Import measured Dk/Df from the Arlon CLTE-MW datasheet into your EM solver material library
• Use actual copper foil roughness parameters (Ra value from the laminate datasheet) in your solver’s roughness model
• Simulate the antenna array element over the realistic substrate stack, including the bondply and any layer below within coupling distance
• Validate patch resonance frequency, input impedance, and E/H-plane radiation patterns before board fabrication

Controlled Impedance for 77 GHz Feed Networks

The feed network connecting the MMIC (typically a silicon-germanium or CMOS radar transceiver) to the antenna array is usually implemented as a coplanar waveguide (CPW) or grounded coplanar waveguide (GCPW) on the CLTE-MW antenna layer. CPW/GCPW offers better isolation and more predictable impedance than microstrip at 77 GHz, and is more tolerant of the ground plane perforation that vias introduce.

For controlled impedance on Arlon CLTE-MW (Dk 3.00):

• Specify impedance target and tolerance on your fabrication drawing (typically 50 ± 5 ohms)
• Include impedance test coupons on the panel border — your fab should be measuring impedance, not just controlling dimensions
• Use Polar Si9000e or equivalent field solver with the measured Dk from the material certificate

Copper Foil Roughness at 77 GHz

Copper surface roughness is a dominant loss mechanism at 77 GHz. Standard electrodeposited (ED) copper with RMS roughness of 1–2 μm contributes substantially to conductor loss at this frequency — sometimes more than the dielectric loss in the substrate itself. For 77 GHz antenna layers, always specify low-profile (LP) or ultra-low-profile (ULP) copper foil. Arlon CLTE-MW is available with LP copper options. The reduction in conductor loss compared to standard ED copper at 77 GHz can be 1–3 dB per inch depending on trace geometry and roughness model — enough to meaningfully extend radar detection range.

Automotive Qualification Considerations for CLTE-MW

AEC-Q200 and Material Stress Testing

AEC-Q200 is the standard for passive component qualification in automotive applications. While it applies formally to components rather than raw laminate, your system-level reliability testing will exercise the PCB material through:

• Thermal shock: -40°C to +125°C, 1000 cycles minimum for most ADAS applications
• Humidity/biased testing: 85°C/85% RH with bias applied
• High-temperature storage: +150°C for 1000 hours (for some under-hood radar positions)
• Vibration: Road-profile vibration per automotive profiles

CLTE-MW’s controlled Z-CTE is the property that most directly supports survival of the thermal shock requirement. Via reliability in multilayer PTFE boards is the most common failure mode in extended thermal cycling, and the 4x reduction in Z-CTE stress that CLTE-MW provides over high-Z-CTE PTFE materials is the difference between passing and failing a 1000-cycle thermal shock qualification.

IATF 16949 and Automotive Supply Chain Requirements

Automotive electronics supply chains increasingly require IATF 16949 certification from all Tier 1 and Tier 2 suppliers. PCB fabricators building your Arlon automotive radar PCB designs should be IATF 16949 certified in addition to holding standard ISO 9001 certification. Verify this during fab selection — many general-purpose PCB shops have ISO 9001 but not the automotive-specific IATF 16949.

Useful Resources for Arlon Automotive Radar PCB Design

Resource	Description	Link
Arlon CLTE-MW Datasheet	Official electrical, mechanical, and thermal specs	arlon-mmc.com
Arlon AD-Series Datasheets	AD250C and AD300D specs for antenna layer alternatives	arlon-mmc.com
IPC-4103 High-Frequency Laminate Standard	Qualification and characterization standard for RF laminates	ipc.org
AEC-Q200 Standard	Automotive passive component stress qualification	aecouncil.com
Ansys HFSS	3D EM simulation for 77 GHz patch arrays and transitions	ansys.com
CST Microwave Studio	Alternative 3D EM solver, strong automotive radar community	3ds.com
Polar Si9000e	Controlled impedance field solver for CPW/GCPW design	polarinstruments.com
Rogers RO3003G2 Datasheet	Key competitor benchmark — useful for comparative evaluation	rogerscorp.com
Isola Astra MT77 Datasheet	Thermoset alternative at 77 GHz for comparison	isola-group.com
RayPCB Arlon PCB Guide	Fabrication overview for Arlon material families	raypcb.com/arlon-pcb

Frequently Asked Questions: Arlon Automotive Radar PCB

Q1: Can Arlon CLTE-MW be used for the full 77 GHz radar module, or only for specific layers?

CLTE-MW is suitable for the 77 GHz antenna array and feed network layers — the layers where the full-frequency signal is present. For the IF processing chain (typically 1–10 GHz intermediate frequency), baseband digital processing, power management, and vehicle interface layers, lower-cost materials are entirely appropriate and preferable from a cost-engineering standpoint. Most production automotive radar modules use a hybrid stack with CLTE-MW or equivalent PTFE for the top 1–2 layers and standard or advanced epoxy (FR4, LD730, or similar) for the remaining layers. All-PTFE construction is technically feasible but cost-prohibitive for high-volume automotive programs.

Q2: How does Arlon CLTE-MW compare to Rogers RO3003G2 for 77 GHz radar applications?

Rogers RO3003G2 is the dominant material in current automotive radar designs and has the most mature simulation model library and fab process documentation. Its Df at 77 GHz is slightly lower than CLTE-MW’s, and it benefits from being the most widely qualified material with the most automotive radar program wins. CLTE-MW is a competitive alternative with comparable Dk, Z-CTE, and electrical performance — it is a natural choice for programs where Arlon is already the preferred supplier, where CLTE-MW is better priced at a given volume, or where the fab has existing CLTE-MW process qualification. For a new program from scratch with no prior material constraints, many engineers default to RO3003G2 for the ecosystem advantage; for programs with existing Arlon relationships, CLTE-MW is a strong choice.

Q3: Does CLTE-MW survive automotive reflow temperatures for SMT assembly?

Yes. PTFE does not have a traditional glass-transition temperature (Tg) in the way epoxy materials do, but it remains dimensionally and electrically stable through standard SAC305 lead-free reflow profiles with peak temperatures of 260°C. PTFE’s melting point is ~327°C, well above reflow peak. The practical concern for PTFE in SMT assembly is not the PTFE matrix itself but the PTFE-to-copper adhesion and any bondply material at PTFE/epoxy interfaces in hybrid stacks — both of which should be evaluated with a test run before full production commitment.

Q4: What is the typical insertion loss for a 77 GHz feed network on Arlon CLTE-MW?

At 77 GHz, a 50-ohm microstrip transmission line on CLTE-MW (Dk 3.00, Df ~0.0018 at 77 GHz) with low-profile copper foil will see approximately 0.8–1.5 dB/inch of total insertion loss, depending on trace geometry, copper roughness, and dielectric thickness. For reference, the same geometry on standard FR4 would be 15–25 dB/inch — completely unusable. In a typical patch array feed network covering 4–6 inches of total trace length from MMIC to array edge, CLTE-MW’s insertion loss is typically 4–8 dB — a manageable budget for the transmit chain gain allocation and the receive chain noise figure. Compare this against Rogers RO3003G2 on similar geometry, and the loss difference is less than 1 dB total — which is why both materials are viable choices.

Q5: What fabrication capability does my PCB fab need to build an Arlon CLTE-MW automotive radar board?

Your fabricator needs full PTFE processing capability: specialized drill parameters for PTFE, plasma or sodium naphthalene surface preparation for via plating, and validated lamination profiles for PTFE/epoxy hybrid constructions. Specifically for automotive programs, IATF 16949 certification is strongly recommended. The fab should also demonstrate controlled impedance measurement capability to ±5 ohms at 77 GHz-relevant frequencies, and ideally have prior automotive radar program experience with hybrid PTFE/epoxy stacks. Request their process capability data on PTFE drilling and PTFE/epoxy hybrid lamination before committing your design — a fab that is new to hybrid PTFE construction will face a learning curve that costs you time and potentially material.

The Practical Bottom Line for Arlon Automotive Radar PCB Design

Automotive 77 GHz radar is one of the most technically demanding commercial PCB applications in volume production today. The substrate material is not a component you can post-design-optimize — it determines your antenna pattern, your insertion loss budget, and your long-term reliability before you place a single component.

Arlon CLTE-MW is a proven, competitive material for 77 GHz antenna and feed network layers. Its Dk stability, low Df, and controlled Z-CTE make it well-matched to the automotive thermal cycling environment, and its PTFE heritage gives it the reliability credentials that automotive Tier 1 programs demand. Pair it with Arlon LD730 or standard FR4 for the IF and digital layers in a well-engineered hybrid stack, and you have a material solution that can carry a program from prototype through full automotive production.

The engineering discipline around 77 GHz substrate selection — EM simulation with accurate material parameters, copper roughness specification, hybrid stack CTE management, and PTFE-qualified fabricator selection — is what separates first-pass successes from programs that spend two or three spins chasing insertion loss numbers and beam pattern anomalies. Get the material selection and stack-up right early, and the rest of the design falls into a manageable framework.

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Complete guide to Arlon automotive radar PCB materials for 77 GHz ADAS applications. Covers CLTE-MW, CLTE-P, and AD-series specs, hybrid stack-up design, insertion loss at 77 GHz, AEC-Q200 reliability, comparison vs Rogers RO3003G2, and fabrication requirements for automotive-grade PTFE PCBs.

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Arlon automotive radar PCB guide: CLTE-MW specs, 77 GHz hybrid stack design, insertion loss, AEC-Q200 reliability, and Rogers RO3003G2 comparison for ADAS engineers.

Complete guide to Arlon aerospace PCB laminate materials including CLTE-MW, CLTE-P, 25N, AD-series, and LD730. Covers phased array radar, EW, satellite, and avionics applications, MIL-PRF-31032 QPL compliance, IPC-6012 Class 3 fabrication requirements, and practical design guidance for defense PCB engineers.

Designing PCBs for aerospace and defense is a different discipline from commercial electronics work. The performance bar is higher, the qualification requirements are more rigorous, the operating environments are more extreme, and the consequences of failure are more severe. When a board in a phased array radar or a satellite transponder fails at 40,000 feet or in low earth orbit, there’s no field service call. You get it right in the design phase, or you live with it.

Material selection sits at the foundation of that design discipline. Arlon aerospace PCB laminate products have been a cornerstone of military and aerospace electronics manufacturing for over six decades, and for good reason — the company’s PTFE composite and specialty thermoset materials were engineered specifically for the thermal, mechanical, and electrical demands that defense programs impose. This guide covers the full picture: which Arlon materials apply to aerospace and defense PCB design, what makes them suitable for these demanding applications, the qualification and compliance landscape, and practical guidance for engineers working in this space.

Why Aerospace and Defense PCBs Demand Specialty Laminates

Before getting into specific Arlon materials, it’s worth being explicit about why standard FR4 is inadequate for most mil-aero applications — and why even commercial-grade RF laminates sometimes fall short.

The Environmental Envelope Is Unforgiving

Military and aerospace electronics routinely operate in conditions that would destroy commercial-grade PCBs. Consider what a typical MIL-STD-810 qualification program throws at a board:

• Temperature cycling from -65°C to +125°C (or beyond, for some platform applications)
• High-altitude operation with near-vacuum thermal convection
• High-vibration environments: jet engines, helicopters, launch vehicles
• High-G shock loads during weapons deployment or crash survivability testing
• Humidity cycling from 5% to 95% RH in tropical environment testing
• Salt fog exposure for naval platforms
• EMI/RFI environments orders of magnitude more severe than commercial spec

Standard FR4 has a Z-axis CTE of ~70 ppm/°C. Across a -65°C to +125°C range (190°C delta), a 100 mil via barrel expands and contracts enough to eventually fatigue and crack copper plating — exactly the kind of latent failure mode that shows up years into a program and is nearly impossible to root-cause in the field. High-performance Arlon aerospace PCB laminate products like CLTE-MW address this with Z-axis CTE values closer to 24 ppm/°C, which reduces the stress on plated through-holes by 3–4x.

RF and Microwave Performance at System Level

Defense electronics are disproportionately RF-intensive compared to commercial products. Radar, electronic warfare, satellite communications, missile guidance, and signals intelligence all involve microwave frequency chains where every tenth of a dB matters. A phased array antenna with 1,000 elements can have its effective isotropic radiated power (EIRP) degraded significantly by a PCB laminate that contributes even small amounts of insertion loss per element. PTFE-based Arlon laminates offer Df values in the 0.0009–0.0016 range — compared to 0.015–0.025 for FR4 — which is what makes them viable for these applications.

Traceability and Qualification Requirements

Defense programs require material traceability in ways commercial programs do not. You can’t simply substitute a “similar” material when your program is qualified to a specific MIL-PRF specification. Arlon maintains QPL (Qualified Products List) certifications for several of its laminate families under MIL-PRF-31032 and IPC-4103, which means the material has been formally tested and approved for use in defense programs that invoke those standards. This is not a marketing claim — it’s a procurement and program management requirement that can determine whether you get your hardware accepted at delivery.

The Arlon Aerospace PCB Laminate Portfolio

Arlon’s product range for aerospace and defense applications spans several distinct material families. Each addresses a different combination of frequency, temperature, and mechanical requirements.

CLTE-MW: The Workhorse of Defense Phased Array and Radar PCBs

If there is a single Arlon material most associated with Arlon aerospace PCB laminate applications, it is CLTE-MW. This woven PTFE composite with controlled Z-axis CTE is the go-to material for multilayer phased array radar front-end modules, electronic warfare receivers, and satellite payload boards.

The controlled Z-CTE (~24 ppm/°C) is the critical property that makes CLTE-MW suitable for multilayer defense boards subjected to wide thermal cycling. Combined with a Df of 0.0012 at 10 GHz and Dk of 3.00, it delivers the electrical performance needed for L-through Ka-band applications while surviving the mechanical and thermal stress of mil-aero qualification programs.

CLTE-MW is qualified under MIL-PRF-31032 and is stocked by Arlon-authorized fabricators with PTFE processing capability. Many defense program specifications written in the 1990s and 2000s reference CLTE-MW (or its legacy equivalents) by name, making it the material of choice not just on engineering merit but by program requirements.

CLTE-P: When Fabrication Yield on Expensive Boards Matters

CLTE-P shares CLTE-MW’s electrical and CTE specifications but adds enhanced mechanical robustness that reduces microcracking during drilling and routing. For high-complexity multilayer PTFE boards — think 20+ layer radar receiver modules with hundreds of vias per panel — CLTE-P’s improved drillability translates directly into better fabrication yield.

In defense programs, board cost is high and schedule is often constrained. A panel of complex multilayer PTFE boards can represent tens of thousands of dollars of material and labor. CLTE-P’s resistance to via wall microcracking and delamination during aggressive drilling sequences protects that investment and reduces program risk during production.

25N: PTFE/Ceramic Composite for Stable High-Frequency Performance

Arlon 25N is a PTFE/microfiberglass ceramic composite material targeting applications where the woven PTFE construction of CLTE-MW is not optimal — particularly designs where in-plane isotropy and tight Dk control are required for precise antenna element and filter design.

With Dk of 3.38 ± 0.05 and Df of 0.0025 at 10 GHz, 25N is well-suited for applications in the 2–18 GHz range including:

• Stripline and microstrip filter banks in electronic warfare systems
• Radome-integrated antenna structures
• Precision microwave hybrid circuits
• L-band through Ku-band satellite receive chains

The ceramic filler loading in 25N provides better dimensional stability during lamination compared to woven PTFE composites, which simplifies registration in large-format multilayer builds. This is a non-trivial advantage in defense applications where tight via-to-copper clearances are common in dense front-end modules.

AD250C and AD300D: Specialty Low-Dk Materials for Specialized Defense Applications

The AD series represents Arlon’s lower-Dk specialty composite materials. AD250C achieves Dk = 2.50 with Df = 0.0015, making it suitable for applications requiring extended guided wavelengths — useful in traveling wave antenna arrays and aperture-coupled patch antenna designs where substrate thickness constraints dictate a lower-Dk material.

AD300D (Dk = 3.00, Df = 0.0020) offers a middle ground between the AD250C and CLTE-MW and sees use in wideband antenna structures and satellite communication feed networks.

85N: High-Temperature PTFE Composite for Extreme Thermal Environments

For applications where operating temperatures exceed what standard PTFE composites can sustain — engine nacelle electronics, hypersonic vehicle avionics, and certain directed energy weapon systems — Arlon 85N provides PTFE composite construction rated for continuous operation above 200°C. This is a relatively niche application, but when you need it, there is no commercial-grade alternative.

LD730 and LD621: Epoxy-Based Options for Lower-Frequency Defense Work

Not every board in a defense system operates at microwave frequencies. Digital processing, power management, bus controllers, and interface electronics often run at frequencies where PTFE is unnecessary. Arlon’s LD730 (Dk 3.0, Df 0.0022) and LD621 (Dk 3.4, Df 0.0030) serve this tier — better than FR4 for the digital high-speed interfaces and modest RF work, processable on standard FR4 equipment, and available with the traceability documentation that defense procurement requires.

Arlon Aerospace PCB Laminate Properties Comparison Table

The table below summarizes the primary Arlon laminates used in aerospace and defense PCB applications with the specifications most relevant to material selection.

Material	Dk @ 10 GHz	Df @ 10 GHz	Z-CTE (ppm/°C)	Tg / Max Temp	Primary Defense Application
CLTE-MW	3.00 ± 0.05	0.0012	~24	>260°C continuous	Phased array radar, EW, satcom payload
CLTE-P	3.00 ± 0.05	0.0013	~24	>260°C continuous	Dense multilayer radar/EW modules
CLTE (base)	2.94 ± 0.05	0.0016	~100	>260°C continuous	Simple 2-layer microwave circuits
25N	3.38 ± 0.05	0.0025	~28	>260°C continuous	Filter banks, L–Ku band hybrid circuits
AD250C	2.50 ± 0.05	0.0015	~25	>260°C continuous	Low-Dk antenna structures
AD300D	3.00 ± 0.05	0.0020	~25	>260°C continuous	Wideband antenna feeds, satcom
85N	3.40 ± 0.05	0.0020	~25	>200°C operating	High-temp avionics, nacelle electronics
LD730	3.00 ± 0.05	0.0022	~42	>170°C (Tg)	Digital/mixed-signal, sub-15 GHz RF
LD621	3.40 ± 0.05	0.0030	~42	>185°C (Tg)	Digital processing, low-freq RF

Qualification Standards and Compliance: What Defense Programs Actually Require

This is the section that engineering programs sometimes underestimate until it’s too late. Specifying an Arlon material in a defense program isn’t just about the Dk and Df — it’s about demonstrating that the material meets the qualification standards written into your program’s procurement documents.

MIL-PRF-31032: The Primary Defense Laminate Standard

MIL-PRF-31032 is the primary U.S. Department of Defense performance specification for printed circuit board laminates. Materials that appear on the QPL (Qualified Products List) for MIL-PRF-31032 have been formally tested and approved. Specifying a QPL-listed material in your design gives your program protection against acceptance disputes and simplifies DLA (Defense Logistics Agency) procurement.

Arlon CLTE-MW and several other Arlon PTFE composites hold QPL listings under MIL-PRF-31032. Verify the current QPL status at the Defense Logistics Agency Land and Maritime website before finalizing your material specification — QPL listings can change with qualification cycle renewals.

IPC-4103: High-Frequency Laminate Qualification Standard

IPC-4103 is the commercial equivalent qualification standard for high-frequency and high-speed laminate materials. While not a military standard, it is often invoked in commercial aerospace programs (DO-254 applications, commercial satellite hardware) and provides a consistent test and documentation framework for laminate qualification. Arlon materials certified to IPC-4103 carry verified electrical, mechanical, and thermal characterization data that supports the traceability requirements of most aerospace quality management systems.

IPC-6012 Class 3 and Class 3A: PCB Fabrication Quality Requirements

The PCB fabrication quality standard IPC-6012 Class 3 applies to aerospace, military, and high-reliability commercial applications. Class 3A adds additional requirements specifically for space applications. When your board is built to IPC-6012 Class 3 (or 3A), the material traceability chain must be intact from laminate mill certificate through fabrication traveler to completed board. Arlon’s production documentation supports this traceability chain for their QPL-listed and IPC-4103 certified materials.

AS9100 and NADCAP Considerations

Many aerospace programs require their fabricators to hold AS9100 certification (Quality Management Systems for Aviation, Space, and Defense). NADCAP (National Aerospace and Defense Contractors Accreditation Program) accreditation for PCB fabrication is required by prime contractors on some programs. When selecting a fabricator for your Arlon aerospace PCB laminate build, verifying their AS9100 certification and NADCAP status (where applicable) is as important as verifying their PTFE processing capability.

Matching Arlon Aerospace Laminates to Defense Application Categories

Phased Array Radar: AESA and PESA Front-End Modules

Active Electronically Scanned Arrays (AESA) are among the most demanding PCB applications in existence. A single AESA face can contain hundreds to thousands of transmit/receive (T/R) modules, each of which is a multilayer microwave PCB operating continuously across a wide temperature range and subjected to the vibration environment of a tactical aircraft or shipboard weapon system.

CLTE-MW is the predominant material for AESA T/R module substrates and manifold boards. The requirements that drive this choice:

• Low Df for minimal insertion loss across the T/R module’s RF chain (typically X-band or Ku-band)
• Controlled Z-CTE to survive thermal cycling from cold-soak ground storage to full-power operation
• Tight Dk tolerance (±0.05) to maintain beam-steering accuracy across all elements
• Compatibility with flip-chip and wirebond attachment of MMICs (Monolithic Microwave Integrated Circuits)
• MIL-PRF-31032 QPL listing for program acceptance

Electronic Warfare: Wideband Receiver and Jammer Hardware

Electronic warfare receivers must cover extremely wide frequency ranges — often 2–18 GHz in a single aperture, with some systems extending into millimeter wave. This wideband requirement places tight constraints on the substrate material:

• Dk stability versus frequency is critical: any dispersion introduces phase errors that degrade detection sensitivity
• Df must be low across the entire operating band, not just at a single frequency
• Hybrid substrate constructions often mix Arlon PTFE layers for RF with standard materials for digital processing

For wideband EW applications, CLTE-MW and 25N are both commonly specified, with CLTE-MW preferred for higher-frequency work and 25N offering better dimensional stability for precision stripline filter and coupler structures.

Satellite Communication and Space Electronics

Space electronics introduce a unique combination of requirements. The thermal cycling range in LEO (Low Earth Orbit) can span from -100°C to +100°C per orbit. Outgassing in vacuum is a concern that many ground-based qualification tests miss. Radiation tolerance adds another dimension.

Arlon CLTE-MW’s low outgassing (verified by NASA GSFC outgassing testing where applicable) and controlled Z-CTE make it suitable for most LEO and GEO satellite payload applications. For the most demanding space applications, AD250C and AD300D see use in phased array feed structures where their lower Dk and tightly controlled properties support precision antenna pattern control.

Space programs typically invoke the most stringent version of the IPC-4103 / IPC-6012 Class 3A requirements, and traceability documentation from material lot through completed board assembly is mandatory.

Missile Guidance and Seekers

Seeker electronics in precision-guided munitions face a genuinely extreme environment: high-G launch loads (thousands of G), rocket motor vibration, aerodynamic heating, and a tight volume envelope. PCBs in seekers are often small, high-layer-count, and must survive shock and vibration testing to MIL-STD-810 Method 516 levels that would destroy conventional assemblies.

For seeker RF front ends, CLTE-P is often preferred over standard CLTE-MW because the improved mechanical robustness reduces microcracking during the high-G shock environment — a material property that pays dividends both in fabrication and in field survivability.

Avionics and Airborne Processing

Not all avionics is microwave. Digital avionics processors, MIL-STD-1553 bus controllers, ARINC 664 (AFDX) network switches, and flight management computers run at frequencies where LD730 or LD621 is appropriate. For these applications, the defense-grade requirement is more about thermal cycling, long service life (20–30+ year program life for many platforms), and material traceability than about extreme RF performance.

Arlon LD730 is used on avionics digital boards where the signal speeds exceed what FR4 handles reliably (DDR4/5 interfaces, PCIe links, high-speed optical interface hosts) and where the thermal and mechanical qualification requirements exceed what commodity FR4 materials are tested to support.

Fabrication Considerations for Arlon Aerospace PCB Laminate Builds

Selecting the right Arlon material is step one. Getting it correctly fabricated is step two — and for PTFE-based Arlon aerospace laminates, the fabrication process is fundamentally different from standard FR4.

Selecting a PTFE-Capable Defense Fabricator

The number of PCB fabricators capable of running multilayer PTFE aerospace boards to IPC-6012 Class 3 is substantially smaller than the general pool of PCB shops. The requirements include:

• Dedicated PTFE drilling lines with appropriate speed/feed parameters
• Sodium naphthalene or plasma etch surface preparation chemistry (separate from FR4 desmear lines)
• AS9100 certification
• ITAR registration for defense hardware
• QPL certification from DLA where required by program
• Full traceability documentation capability

Before finalizing your design with an Arlon aerospace PTFE laminate, confirm your fabricator is qualified on the specific material. Don’t assume that PTFE capability on one Arlon product extends to all PTFE products — process parameters vary between the woven CLTE family and ceramic-composite materials like 25N.

Via Design for Thermal Reliability

The improved Z-CTE of CLTE-MW (~24 ppm/°C) versus FR4 (~70 ppm/°C) substantially reduces via fatigue risk, but thermal reliability engineering still matters for the most demanding applications. Best practices for via design in aerospace PTFE boards:

• Back-drill via stubs on high-frequency signal layers to eliminate resonances and reduce stub capacitance
• Use filled-and-capped vias for thermal and high-current applications to maximize copper content in the barrel
• Size anti-pad diameters carefully — oversized anti-pads increase impedance discontinuity
• Specify annular ring minimums appropriate for IPC-6012 Class 3 (larger than Class 2)

Copper Foil Selection

At frequencies above 5 GHz, copper surface roughness contributes meaningfully to conductor loss. For aerospace RF boards on CLTE-MW or 25N, specifying low-profile (LP) or reverse-treated (RTF) copper foil on RF signal layers is standard practice. Both Arlon and competing laminate suppliers offer their PTFE materials with these copper options, and the conductor loss reduction at 10+ GHz is significant enough to be worth specifying.

Resources for Arlon Aerospace PCB Laminate Design and Procurement

Resource	Description	Link
Arlon Electronic Materials	Official datasheets and qualification documentation	arlon-mmc.com
DLA QPL MIL-PRF-31032	Defense Logistics Agency Qualified Products List	landandmaritime.dla.mil
IPC-4103 Standard	Qualification spec for high-frequency laminates	ipc.org
IPC-6012 Class 3/3A	PCB qualification and performance for high-reliability/space	ipc.org
MIL-STD-810	Environmental test methods for military hardware	everyspec.com
MIL-STD-461	EMI/EMC test requirements for military equipment	everyspec.com
NASA GSFC Outgassing Database	Material outgassing data for space qualification	outgassing.nasa.gov
Ansys HFSS	3D EM simulation for phased array and filter design	ansys.com
Polar Si9000e	Controlled impedance field solver	polarinstruments.com
RayPCB Arlon PCB Guide	Fabrication overview for Arlon PCB material families	raypcb.com/arlon-pcb

Frequently Asked Questions: Arlon Aerospace PCB Laminate

Q1: Which Arlon material is most commonly specified in U.S. defense phased array radar programs?

CLTE-MW is the dominant choice for multilayer AESA front-end module PCBs. Its combination of Dk 3.00, Df 0.0012, controlled Z-CTE (~24 ppm/°C), and QPL listing under MIL-PRF-31032 satisfies the core electrical, thermal reliability, and procurement compliance requirements of U.S. radar programs. Many legacy program specifications written in the 1990s and 2000s reference CLTE-MW explicitly, which means it appears on approved materials lists for active platforms regardless of whether newer alternatives might also qualify. For new program starts, CLTE-MW is also the first material most defense-focused RF PCB engineers would reach for in the phased array application space.

Q2: How do Arlon’s aerospace laminates compare to Rogers RT/duroid 5880 for defense applications?

RT/duroid 5880 offers a lower Df (0.0009 vs CLTE-MW’s 0.0012) and lower Dk (2.20 vs 3.00), making it theoretically better for the most loss-sensitive applications and for frequencies above 40 GHz. However, RT/duroid 5880’s Z-CTE of ~237 ppm/°C makes it problematic in thick multilayer constructions subjected to wide thermal cycling — the via reliability issue is severe. Arlon CLTE-MW’s controlled Z-CTE is a fundamental structural advantage over RT/duroid 5880 for multilayer defense boards. In practice, RT/duroid 5880 is used in thin, simple constructions (1–4 layers) where via depth is short, and CLTE-MW is used in complex multilayer builds. They serve overlapping but distinct applications.

Q3: Can Arlon aerospace laminates be processed at standard commercial PCB fabs, or is a specialized defense fab required?

For PTFE-based Arlon materials (CLTE-MW, CLTE-P, 25N, AD-series), a fabricator with PTFE-specific process capabilities is required. This is not just a best practice — processing PTFE materials on standard FR4 equipment produces unacceptable results. Additionally, for hardware destined for U.S. defense programs, ITAR registration is mandatory for the fabricator, and AS9100 certification is typically required for aerospace programs. For Arlon’s epoxy-based LD-series materials (LD730, LD621), standard FR4 processing capability is sufficient, and the fab qualification requirement is less restrictive.

Q4: What documentation does Arlon provide to support defense program traceability requirements?

Arlon provides material certificates of conformance (C of C) with each shipment, including lot traceability to raw material batch. For QPL-listed materials, the C of C includes QPL qualification status documentation. Full qualification test reports can be requested for program-level qualification activities. When selecting a fabricator for defense work, confirm that they maintain the material documentation through their fabrication traveler so the traceability chain is intact from Arlon mill certificate through the finished PCB and into the assembly traveler.

Q5: Are Arlon aerospace laminates suitable for space applications, and what outgassing data is available?

Several Arlon PTFE composites — particularly CLTE-MW and the AD-series — have been used in satellite and space applications. The primary additional concern for space qualification beyond standard aerospace use is outgassing: materials used in sealed spacecraft environments must meet ASTM E595 or NASA GSFC criteria for total mass loss (TML < 1.0%) and collected volatile condensable material (CVCM < 0.10%). Arlon has tested selected materials against these criteria, and outgassing data may be available from Arlon’s technical support team or through the NASA GSFC materials outgassing database. For any new space program, material lot-level outgassing testing is strongly recommended given the variability that can exist between production lots.

Final Perspective: Why Arlon Continues to Lead in Aerospace and Defense PCB Materials

The reason Arlon aerospace PCB laminate products have maintained their position in defense electronics for over six decades isn’t purely technical. It’s the combination of technical performance, qualification pedigree, program traceability, and the fact that Arlon’s parent company Sanmina operates EMS facilities that run these same materials in production. That vertical integration between material supplier and production EMS gives defense program managers a level of supply chain confidence that matters when you’re trying to sustain a platform for 30 years.

For engineers entering the defense electronics design space, the learning curve on material selection is real. The QPL requirements, the PTFE processing constraints, the traceability documentation — none of it exists in commercial RF design. But the framework is learnable, and once you understand why each requirement exists, the material selection decisions become straightforward.

Start with CLTE-MW for any serious multilayer defense RF board. Understand what the Z-CTE improvement means for your thermal cycling profile. Verify your fab’s PTFE process capability and their AS9100 status before you tape out. And keep the program’s material traceability documentation chain intact from mill certificate through final assembly acceptance.

Do those things, and Arlon’s aerospace laminate portfolio has the performance and qualification credentials to support whatever mission profile you’re designing for.

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Complete guide to Arlon aerospace PCB laminate materials including CLTE-MW, CLTE-P, 25N, AD-series, and LD730. Covers phased array radar, EW, satellite, and avionics applications, MIL-PRF-31032 QPL compliance, IPC-6012 Class 3 fabrication requirements, and practical design guidance for defense PCB engineers.

Trimmed version for Google (159 characters — within Yoast green zone):

Arlon aerospace PCB laminate guide: CLTE-MW, 25N, AD-series specs, phased array radar and satcom applications, MIL-PRF-31032 compliance, and defense fabrication requirements.

Option A — it leads with the target keyword naturally, hits Dk (a high-intent search term for this material), and signals the page depth (specs + fabrication + comparison) that satisfies both informational and commercial-investigation search intent.

If you’ve spent any time designing microwave or RF boards, you know that material selection can make or break a design — especially when you’re under pressure to shrink board real estate without sacrificing electrical performance. That’s exactly the problem Arlon AD600 was built to solve. As a woven fiberglass reinforced, ceramic-filled, PTFE-based composite laminate with a nominal dielectric constant of 6.15, AD600 sits in a practical sweet spot between standard PTFE materials and brittle pure ceramic substrates.

This article breaks down everything a PCB design or manufacturing engineer needs to know about Arlon AD600 — from material composition and key specs to fabrication tips, typical use cases, and how it stacks up against comparable materials.

What Is Arlon AD600?

Arlon AD600 is a PTFE-based composite laminate developed specifically for the 6.15 dielectric constant (Dk) market. The material combines three key components: a PTFE fluoropolymer matrix, woven fiberglass reinforcement, and micro-dispersed ceramic filler. Each of these elements contributes something important to the overall performance profile.

The PTFE base delivers the low-loss, thermally stable foundation. The woven glass reinforcement adds dimensional stability and mechanical robustness — something you simply don’t get from unfilled PTFE or from brittle ceramic substrates like alumina or LTCC. The ceramic loading is what drives the dielectric constant up to 6.15, enabling significant circuit miniaturization compared to lower-Dk PTFE materials in the 2.2–3.5 range.

AD600 is considered a “legacy product” in Arlon’s current lineup, with Arlon officially recommending the upgrade path to TC600 for new designs requiring higher thermal conductivity and tighter Dk tolerance. However, AD600 remains a widely used and well-characterized substrate across a broad installed base of RF designs, and many manufacturers still stock it. Understanding it thoroughly is worthwhile, both for working with legacy designs and for appreciating the engineering tradeoffs in this class of material.

Arlon is now part of Rogers Corporation, and the AD-series materials sit within the Rogers/Arlon portfolio of high-frequency laminates. If you’re sourcing or manufacturing these boards, working with an experienced fabricator who understands Arlon PCB materials is essential.

Arlon AD600 Key Electrical and Mechanical Specifications

Understanding the full spec sheet is critical before committing to a design. The table below summarizes the typical properties for Arlon AD600.

Property	Value	Test Method
Dielectric Constant (Dk)	6.15 ± 0.15 @ 10 GHz	IPC TM-650 2.5.5.5
Dissipation Factor (Df)	0.0027 @ 10 GHz	IPC TM-650 2.5.5.5
Thermal Coefficient of Dk (TCDk)	-90 ppm/°C	IPC TM-650 2.5.5.7
Volume Resistivity	>10^7 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)	> 5.0 lbs/in	IPC TM-650 2.4.8
CTE (X-axis)	~16 ppm/°C	IPC TM-650 2.4.41
CTE (Z-axis)	~25 ppm/°C	IPC TM-650 2.4.41
Thermal Conductivity	~0.5 W/m·K	ASTM E1461
Standard Panel Size	18″ × 24″	—

Note: These are typical values, not specification limits. Actual performance varies with laminate thickness and design. Always verify against the official Arlon datasheet before finalizing a design.

The Dk of 6.15 is the defining number here. For context, standard Rogers RT/duroid 5880 has a Dk of 2.2, meaning that a circuit built on AD600 can be roughly √(6.15/2.2) ≈ 1.67× smaller in the planar dimension for the same electrical behavior. For patch antennas, that’s a significant real estate reduction.

Available Thicknesses for Arlon AD600

One practical consideration is available thickness options. The table below reflects the standard copper-clad laminate offerings:

Thickness (inches)	Thickness (mm)	Nominal Dk
0.024″	0.610	6.15
0.030″	0.762	6.15
0.060″	1.524	6.15
0.125″	3.175	6.15

Copper cladding is typically available in 0.5 oz, 1 oz, and 2 oz electrodeposited (ED) copper. Heavy copper or specialty foils like Ohmega-Ply may be available on request. Be aware that the dielectric constant value is sensitive to laminate thickness, so confirm the exact Dk at your specific thickness when designing precision-matched circuits.

Why a Dielectric Constant of 6.15 Matters for Miniaturization

This is where it helps to think like a designer rather than a materials scientist. When you’re laying out a microwave circuit — say, a Wilkinson power divider operating at 2.4 GHz — the quarter-wave transmission line length is inversely proportional to √Dk of the substrate. A higher Dk directly shrinks the length of that line.

On a standard 50-ohm substrate like Rogers 4003 (Dk ≈ 3.55), your quarter-wave line at 2.4 GHz might run around 20 mm. On AD600’s Dk of 6.15, that same line comes in around 15 mm — a meaningful reduction when you’re fitting six or eight of those lines into a combiner network.

More importantly, AD600 is particularly beneficial for low-impedance lines, which appear constantly in power amplifier matching networks, filters, and couplers. Low-impedance lines are physically wider on low-Dk materials, making tight layouts essentially impossible. The elevated Dk of AD600 narrows those lines to manageable widths even on thicker substrates.

Mechanical Robustness: Where AD600 Beats Pure Ceramics

Here’s something that doesn’t always get enough attention in material selection discussions: processability matters as much as electrical performance in volume manufacturing.

Pure ceramic substrates like alumina (Al₂O₃) or LTCC offer excellent high-frequency performance and very stable dielectric properties. But they’re brittle. They crack during drilling, they can’t be routed without specialized tooling, and they fail drop and impact tests — a real problem for handheld and consumer RF products. Handling yield losses can be punishing in production.

AD600 solves this by suspending the ceramic filler in a PTFE matrix reinforced with woven glass. The result is a substrate that behaves more like a conventional PCB laminate during fabrication. It can be cut and routed using standard tooling (with appropriate adjustments — more on that below). It passes shock and vibration requirements that would destroy a ceramic board. And because it comes in standard 18″ × 24″ panel sizes, multi-circuit layouts are straightforward.

This is why AD600 is described as a “soft substrate” — not in a negative sense, but in the sense that it absorbs mechanical stress without cracking, which is exactly what you need when your product will end up on a factory floor, inside a vehicle, or in a ruggedized handheld device.

Typical Applications for Arlon AD600

The combination of 6.15 Dk, low loss, and mechanical robustness makes AD600 well-suited for a specific and important set of RF applications:

Application Category	Specific Use Cases
Antenna Designs	GPS patch antennas, DAB/Satellite Radio antennas, RFID reader antennas
Passive RF Components	Microwave power dividers, combiner boards, hybrid couplers, bandpass filters
Active RF Circuits	Power amplifiers (PAs), low noise amplifiers (LNAs), low noise block downconverters (LNBs)
Communication Systems	Satellite uplink/downlink modules, cellular base station feeds
Radar & Avionics	TCAS modules, ground-based radar front ends
Consumer Electronics	Hand-held RFID readers, compact IoT RF modules

The GPS antenna application is a particularly instructive example. At the L1 GPS frequency of 1.575 GHz, a square patch antenna on a 3.55 Dk material would be approximately 50 mm on a side. On AD600, that same resonant patch shrinks to around 38 mm — over 40% smaller in area. That reduction fits the patch antenna into a much smaller product enclosure, which has become a hard design constraint in most modern GPS receivers and tracking devices.

AD600 vs. TC600 vs. AD1000: Choosing the Right Arlon High-Dk Laminate

Engineers frequently face a decision between AD600 and its newer counterparts in the Arlon lineup. Here’s a practical comparison:

Parameter	AD600	TC600	AD1000
Nominal Dk	6.15	6.15	10.2
Dissipation Factor @ 10 GHz	~0.0027	~0.0022	~0.0023
Thermal Conductivity (W/m·K)	~0.5	~1.0	~0.7
Dk Tolerance	±0.15	Tighter	±0.50
Primary Advantage	Proven, widely available	Lower loss + better thermal	Highest miniaturization
Status	Legacy	Recommended upgrade	Active

TC600 doubles the thermal conductivity of AD600 at the same Dk, which directly improves reliability in power amplifier boards where junction temperatures matter. If you’re designing a new high-power PA and have the option, TC600 is the better choice for thermal management. AD600 remains valid if you’re maintaining an existing design, if your supply chain is already qualified on AD600, or if the thermal budget is not a concern.

AD1000 at Dk 10.2 provides even more aggressive miniaturization than AD600, with circuit sizes shrinking by a further ~30% compared to AD600. However, at Dk 10.2, line widths get very tight, impedance control becomes more demanding, and the material is significantly thinner in available form factors. Choose AD1000 when board area is the primary constraint and you’re confident in your fabricator’s impedance control capability.

Fabrication Guidelines for Arlon AD600

This is where field experience really counts. Many fabrication problems with PTFE-based laminates come not from the material itself but from applying FR4 processing parameters to a substrate that behaves very differently.

Cutting and Routing

AD600 is a soft substrate and is readily cut using standard shearing equipment or routing. Unlike ceramics, it does not require diamond tooling. However, burring and smearing can occur if tooling is dull. Use fresh, sharp router bits and ensure your feed rates are appropriate for PTFE-based materials. The soft PTFE matrix tends to compress slightly under excessive heat, so avoid high-speed routing without adequate chip clearing.

Drilling

PTFE-based laminates require specific drilling parameters. The key issues are smear and hole wall quality. Recommendations from Arlon’s fabrication guidelines include:

• Use carbide drill bits with sharp cutting edges
• Drill at lower stack heights than FR4 — typically 1–2 panels per stack
• Use appropriate entry and backup materials to support clean hole entry and exit
• Inspect hole walls under magnification before plating; PTFE smear in the holes is a reliability killer

Plating Preparation

PTFE is chemically inert, which is great for dielectric stability but problematic for plating adhesion. You must use a sodium etchant (sodium naphthalate or sodium ammonia) treatment, or a plasma etch, to activate the PTFE hole walls before electroless copper deposition. Skipping this step or under-etching it is one of the most common causes of poor plated through-hole (PTH) reliability on PTFE laminates.

Etching and Copper Processing

AD600 uses standard electrodeposited copper foils. Standard cupric chloride or ammoniacal etchants work well. Peel strength on AD600 is typically above 5 lbs/inch, which is adequate for fine line work, though not as high as some thermoset materials. Handle panels carefully to avoid peeling during processing.

Soldering and Assembly

PTFE-based boards have low moisture absorption (under 0.10%), which is advantageous during soldering — you won’t trap moisture in the board that would outgas during reflow. AD600 is compatible with standard SMT reflow processes, though the low thermal conductivity of PTFE-based laminates means components heat at different rates than on FR4. Profile your oven accordingly.

Common Design Pitfalls with AD600

Based on real production experience with high-frequency PTFE laminates, here are mistakes worth avoiding:

Ignoring Dk variation with thickness. The dielectric constant is not fixed across all thickness options. At thinner substrates, the effective Dk can shift slightly. Verify the Dk for your specific thickness and back it out in your EM simulation.

Underestimating lamination pressure sensitivity. In multilayer designs involving AD600, improper lamination pressure leads to Dk variation across the panel, which translates directly to impedance spread and phase inconsistency. Establish lamination parameters carefully and validate with test coupons.

Not qualifying the PTFE hole treatment. PTFE activation is not optional. Every PTH in an AD600 multilayer board is at risk without proper sodium etch or plasma treatment. Verify your fabricator’s process explicitly.

Comparing line widths using FR4 calculators. Always recalculate trace widths and gap spacings using the correct Dk and thickness for AD600. A 50-ohm line on FR4 at the same substrate thickness is a very different width from a 50-ohm line on AD600.

Useful Resources for Arlon AD600 Engineers

Resource	Description	Link
Arlon AD600 Datasheet	Official electrical and mechanical specifications	Rogers/Arlon website
AD1000 & AD600 Fabrication Guidelines	Detailed PCB fabrication best practices (PDF)	Available via Arlon/Rogers documentation portal
Arlon Microwave & RF Materials Guide	Full AD series comparison and selection tables	Request from Rogers Customer Service
IPC TM-650 Test Methods	Dielectric constant and loss tangent test standards	IPC.org
MatWeb AD600 Data Entry	Third-party material database entry with converted units	MatWeb
RayPCB Arlon PCB Resource	PCB manufacturing guidance for Arlon materials	RayPCB Arlon PCB

Frequently Asked Questions About Arlon AD600

1. Is Arlon AD600 still in production, or has it been discontinued?

Arlon officially classifies AD600 as a legacy product and directs new designs toward TC600, which offers improved thermal conductivity and lower dissipation factor at the same 6.15 Dk. However, AD600A — an improved version with tighter Dk tolerance — may also be available for cost-sensitive applications at thicker dimensions. If you’re starting a new design, evaluate TC600 first; if you’re maintaining an existing AD600 design, confirm supply availability with your distributor.

2. Can AD600 be used in multilayer PCB stackups?

Yes. AD600 is compatible with multilayer construction, though it requires appropriate bonding plies (prepregs) compatible with PTFE-based laminates. Standard FR4 prepregs are not appropriate bonding materials for PTFE laminates. Use Arlon’s compatible bonding films or consult your fabricator’s recommended stackup for high-Dk PTFE multilayers.

3. How does AD600’s Dk stability compare over temperature?

The TCDk for AD600 is approximately -90 ppm/°C, which means the dielectric constant decreases slightly as temperature rises. For most applications this is manageable, but precision phase-matching circuits (such as in phased array feeds or narrow bandpass filters) should be designed with this drift in mind. TC600 improves on this with better thermal-electric stability.

4. What copper foil options are available with AD600?

AD600 is typically supplied with 0.5 oz, 1 oz, and 2 oz electrodeposited (ED) copper. Rolled annealed (RA) copper may be available and is sometimes preferred for fine-line work because of its smoother surface profile, which reduces conductor losses at millimeter-wave frequencies. Verify specific foil options with your supplier or Arlon’s applications engineering team.

5. What’s the difference between AD600 and Rogers RT/duroid 6006?

Both materials target the Dk ~6 market for high-frequency PCBs. Rogers RT/duroid 6006 has a nominal Dk of 6.15 as well, making them direct competitors. The key differences typically come down to Dk tolerance, dissipation factor consistency, panel size availability, and fabricator familiarity. AD600 has the advantage of large panel sizes (18″ × 24″) and a well-established fabrication process at shops experienced with Arlon materials. For a specific project, request material samples and review incoming Dk lot-to-lot consistency data from your supplier.

Final Thoughts

Arlon AD600 has earned its place as a dependable, well-understood material in the toolkit of RF and microwave PCB engineers. Its combination of a 6.15 dielectric constant, low dissipation factor, mechanical robustness, and PTFE-standard processability makes it a practical solution for antenna miniaturization, power divider boards, PA matching networks, and a wide range of other microwave applications.

That said, any engineer starting a new design today should seriously evaluate TC600 as the more capable successor. The improved thermal conductivity and tighter Dk tolerance of TC600 address two of the most common failure modes in high-power and precision RF applications. AD600 remains relevant for legacy designs, cost-constrained builds, and applications where its proven performance profile is sufficient.

Material selection in RF design is never just about the datasheet number. It’s about understanding how the substrate behaves through the full fabrication and assembly process, across temperature and humidity, and under the mechanical stresses of the real world. AD600 has been doing that job reliably for decades — and that track record counts for something.

Arlon AD450 PCB laminate: full dielectric properties, datasheet specs, Dk 4.5 performance, and real-world RF/microwave applications explained by engineers, for engineers.

If you’ve spent any time specifying materials for RF or microwave PCB designs, you’ve probably hit the same wall most engineers hit: FR-4 works fine up to a point, and then it simply doesn’t. The signal gets sloppy, insertion loss climbs, and your antenna patterns stop matching simulation. That’s usually when the search for a better substrate begins — and Arlon AD450 is one of the materials that comes up early in that conversation.

This article walks through what AD450 actually is, what its datasheet numbers mean in practice, how it compares to alternatives, and when it genuinely makes sense to specify it over other options.

What Is Arlon AD450?

Arlon AD450 is a woven fiberglass reinforced, ceramic-filled, PTFE-based composite laminate designed for use as a printed circuit board substrate in microwave and RF applications. It belongs to Arlon’s AD (Advanced Dielectric) series, a family of cost-optimized PTFE and ceramic composite materials aimed at commercial wireless, antenna, and broadband applications.

The “450” in the product name corresponds to its nominal dielectric constant of 4.5 — a deliberate design decision that makes it a near drop-in replacement for FR-4 from an impedance and trace geometry standpoint. Most FR-4 designs hover around a Dk of 4.2–4.8 depending on glass style, frequency, and manufacturing variability. AD450 hits 4.5 with far tighter consistency and much better high-frequency performance.

Originally, Arlon offered AR450, which used non-woven fiberglass reinforcement. AD450 was developed as its successor, with the switch to woven fiberglass delivering better Dk uniformity across a panel, improved dimensional stability, and reduced manufacturing costs. If you’re quoting fabrication on a design originally specified for AR450, AD450 is the direct replacement Arlon recommends.

It’s worth noting that following Rogers Corporation’s acquisition of Arlon’s electronic materials division, AD450 is now sometimes referenced as a Rogers product. The datasheet and material specs remain the same.

Arlon AD450 Key Dielectric Properties

This is where most engineers need to spend time before committing to a design. The table below summarizes the critical electrical and physical properties of Arlon AD450 based on its published datasheet.

Electrical Properties

Property	Value	Test Method
Dielectric Constant (Dk)	4.5 (nominal)	IPC TM-650 2.5.5.6
Dissipation Factor (Df)	~0.002 (at 10 GHz)	IPC TM-650 2.5.5.6
Dk Stability vs. Frequency	Excellent — flat across frequency	—
Df Stability vs. Frequency	Excellent — stable across frequency	—
Volume Resistivity	High	IPC TM-650 2.5.17.1
Surface Resistivity	High	IPC TM-650 2.5.17.1

The Dk of 4.5 is notably stable across a wide frequency range — from low microwave through the higher GHz bands. This is one of the most important differences from FR-4, whose Dk can shift by 0.3–0.5 across frequency, creating impedance drift in broadband designs. For any design where signal fidelity across a wide bandwidth matters — wideband antennas, multimedia transmission systems, multi-band transceivers — that stability directly affects your return loss and insertion loss budget.

The dissipation factor is where PTFE-based materials like AD450 really separate themselves from standard epoxy laminates. FR-4 Df typically runs 0.02–0.025 at microwave frequencies. AD450’s Df in the 0.002 range is roughly a 10× improvement. Over a few inches of trace at 5–10 GHz, that translates to measurable signal preservation.

Thermal and Mechanical Properties

Property	Value
Thermal Conductivity	Higher than standard PTFE laminates
Z-axis CTE	Low (improved vs. standard PTFE)
X-Y CTE	Stable, woven glass controlled
Copper Peel Strength	Superior PTH adhesion
Panel Size	Large panel format available (36″ × 48″ master sheet)

The ceramic filler in AD450 serves a dual purpose. First, it raises the Dk to 4.5 — pure PTFE without filler lands around 2.1, far too low to be useful as a direct FR-4 replacement. Second, it improves thermal conductivity relative to unfilled PTFE, which is naturally a poor thermal conductor. That matters in power amplifier boards and other high-dissipation applications where heat buildup degrades PTFE performance over time.

The low Z-axis CTE is particularly valuable for plated through-hole (PTH) reliability. Standard PTFE laminates expand significantly in the Z-axis under thermal cycling, which creates stress on barrel-plated holes and can lead to fatigue failures. The ceramic loading in AD450 pulls Z-axis CTE down, bringing it closer to the behavior of conventional epoxy laminates and improving PTH reliability substantially.

Standard Thickness Availability

Thickness (inches)	Thickness (mm)
0.010″	0.254
0.020″	0.508
0.030″	0.762
0.040″	1.016
0.050″	1.270
0.060″	1.524
0.070″	1.778

Available with standard 1 oz and 2 oz rolled copper foil. Immersion gold (ENIG) finish is commonly specified for antenna and RF applications where solderability and surface oxidation are concerns. The large master sheet size (36″ × 48″) makes it practical to run multiple boards per panel, which helps manage per-unit cost on production runs.

AD450 vs. AR450: Understanding the Upgrade

Engineers who’ve been in this space for a while will remember the AR450 — Arlon’s earlier non-woven fiberglass / PTFE / ceramic composite with essentially the same target Dk. The switch from non-woven to woven fiberglass reinforcement in AD450 brought three practical improvements:

Better Dk uniformity across a panel. Non-woven glass fiber distribution is inherently less consistent than woven glass. Woven styles give you more predictable Dk from point to point, which directly improves impedance control tolerance across a production panel.

Better dimensional stability. Woven glass constrains X-Y movement more uniformly. For fine-feature microwave circuitry where trace width tolerances are tight, better dimensional stability reduces registration errors in etching and drilling.

Reduced manufacturing cost. Woven glass styles used in AD450 are more widely available and easier to process than some non-woven alternatives. This makes the material more accessible for volume production without a cost penalty.

The electrical performance remains comparable to AR450, so legacy designs specified on AR450 should translate directly with no required trace geometry changes.

Arlon AD450 Applications

Wideband Antenna Designs

This is probably the most common home for AD450 in the field. Wideband and multi-band antennas — including patch arrays, slot antennas, and monopoles operating from UHF through low microwave — benefit enormously from a substrate with stable Dk across frequency. When Dk shifts with frequency, your resonant structures shift with it, degrading gain and matching bandwidth. AD450’s flat Dk response allows antenna designers to simulate accurately and build to spec.

FR-4 Replacement in Higher Frequency Applications

One of the explicit design goals for AD450 was to make FR-4 replacement as painless as possible. With Dk = 4.5, trace widths calculated for FR-4 transfer with minimal adjustment. This makes AD450 attractive for product upgrades where a design originally built on FR-4 has outgrown its frequency ceiling — whether due to a new frequency band requirement, tighter signal integrity spec, or reliability concerns at elevated temperatures.

A common scenario: a WiFi or LTE module board designed for 2.4 GHz on FR-4 needs to be extended to cover 5.8 GHz or new 6 GHz bands. Redesigning for AD450 gives you meaningful margin in Df and Dk stability without redesigning your entire trace geometry.

Multimedia Transmission Systems

Broadband signal transmission for multimedia — think set-top box RF front ends, point-to-point wireless links, and cable headend equipment — places a premium on consistent signal fidelity across a wide channel. AD450’s combination of low Df and stable Dk makes it a reliable substrate for these systems.

Circuit Board Miniaturization

Higher Dk materials allow physically shorter transmission line structures for a given electrical length. At Dk = 4.5, AD450 permits meaningful miniaturization compared to lower-Dk PTFE substrates while still outperforming FR-4 in signal quality. For embedded RF front-ends where board area is at a premium, this combination of density and performance is practical.

High-Power RF Designs

The ceramic loading that lifts AD450’s Dk also improves its thermal conductivity compared to unfilled PTFE. Combined with low Z-axis CTE, this makes it usable in power amplifier boards and combiner networks where heat dissipation and dimensional stability under thermal cycling both matter. Applications here include base station power amplifiers, radar transmit modules, and industrial RF generators.

Arlon AD450 vs. Competing Materials

Choosing a laminate is never just about one material’s spec sheet — it’s about fit for your specific application, process compatibility, and cost envelope. Here’s how AD450 sits relative to common alternatives.

AD450 vs. FR-4

Parameter	FR-4	Arlon AD450
Dielectric Constant (Dk)	~4.2–4.8 (variable)	4.5 (stable)
Dissipation Factor (Df)	0.020–0.025	~0.002
Dk vs. Frequency	Drifts noticeably	Very stable
Thermal Conductivity	~0.3 W/m·K	Higher
Z-axis CTE	High	Low (ceramic loaded)
Cost	Low	Moderate to high
Processability	Standard	PTFE-compatible process

FR-4 remains the right answer for the vast majority of digital and low-frequency analog designs. But once you’re running signals above 1–2 GHz with any meaningful path length, the gap in dissipation factor starts showing up as measurable insertion loss and pattern distortion. AD450 is the sensible step up when FR-4 performance runs out.

AD450 vs. Rogers RO4003C

Parameter	Rogers RO4003C	Arlon AD450
Dielectric Constant (Dk)	3.55	4.5
Dissipation Factor (Df)	0.0027 at 10 GHz	~0.002
Base Material	Ceramic-filled thermoset	Ceramic-filled PTFE
FR-4 Processability	Yes (thermoset)	Requires PTFE process
CTE	Low	Low
Typical Use	General RF/microwave	FR-4 replacement, antennas

RO4003C is a ceramic-filled hydrocarbon thermoset rather than PTFE — it processes much like FR-4, which simplifies fabrication. If your fab house doesn’t have strong PTFE processing capability, RO4003C may be easier to execute reliably. For designs where Dk = 4.5 is specifically needed for FR-4 geometry compatibility, AD450 is the better match.

AD450 vs. Arlon AD600

AD600 offers a higher dielectric constant (Dk ~6.0) and is aimed at applications requiring more aggressive miniaturization — ultrathin antenna substrates and multilayer circuits where physical size is the primary constraint. If you need smaller structures and can tolerate the trace width recalculation that comes with a higher Dk material, AD600 is worth evaluating. AD450 is the better general-purpose FR-4 replacement.

Processing and Fabrication Notes for Arlon AD450

AD450 is processed using standard PTFE-based PCB substrate methods. If you’ve built boards on Arlon DiClad, CuClad, or IsoClad series materials, the process is familiar. A few points worth flagging for engineers working with fabricators who primarily run FR-4:

PTFE prep requirements. PTFE-based materials need sodium etching or plasma treatment before plating to achieve adequate adhesion. Standard FR-4 adhesion promotion chemistries won’t work. Confirm your fabricator has this capability before quoting.

Drilling. PTFE is soft and somewhat springy compared to FR-4. Entry and exit materials, drill geometry, and feed rates need to be dialed in for clean hole quality. Most fabricators with microwave laminate experience handle this routinely.

Dimensional stability. AD450’s woven glass construction gives it better dimensional stability than non-woven PTFE laminates, but it still won’t match FR-4’s rigidity for large-format boards. For boards larger than 8–10 inches in either dimension, confirm your design can tolerate the somewhat lower rigidity.

PTH reliability. The ceramic loading and low Z-axis CTE of AD450 improve PTH reliability significantly compared to unfilled PTFE laminates. This is one of the specific engineering improvements AD450 makes over traditional PTFE materials.

Arlon publishes fabrication guidelines specifically for DiClad, CuClad, IsoClad, and AD Series laminates — these are worth downloading and sharing with your fabricator before kickoff.

For engineers looking to build on Arlon PCB materials including AD450, working with a fabricator who has established PTFE processing capability is the single biggest factor in getting consistent results.

Datasheet and Specification Resources

Finding current Arlon datasheet information can be slightly confusing now that Rogers acquired Arlon’s electronic materials division. Here are the most reliable places to find spec data:

Resource	What You’ll Find
Rogers Corporation AD450 Product Page	Current datasheet, specs, ordering info
Arlon RF & Microwave Materials Guide (PDF)	AD series comparison table, thickness availability
Arlon AD Series PDF via Cirexx	Dk vs. frequency curves, Df vs. frequency curves
RF Global Net — AD450 Laminate Page	Fabrication guide download link, application notes
IPC TM-650 Test Methods	Reference for how Dk and Df values are measured

The Dk vs. frequency and Df vs. frequency curves in the AD Series datasheet are particularly useful during the material selection phase — they let you validate performance at your specific operating frequency rather than relying on a single-point spec value.

AD450 Design Considerations: A Few Things Engineers Miss

Dk tolerance matters more than the nominal value. When designing transmission lines, patch antennas, or filters, the tolerance on Dk directly affects your impedance tolerance. AD450 offers tighter Dk control than typical non-woven PTFE laminates — use this in your impedance budget calculation rather than just the nominal 4.5 value.

Dissipation factor at operating frequency. The datasheet Df value is typically reported at 10 GHz. If your operating frequency is significantly different, check the Df vs. frequency curve. PTFE-based materials are generally well-behaved across frequency, but confirming this for your specific band is good practice.

Thermal management in power applications. AD450’s improved thermal conductivity relative to unfilled PTFE is a genuine benefit, but if you’re running significant RF power (tens of watts or more), plan your thermal vias and heatsinking accordingly. Improved doesn’t mean unlimited.

Copper foil surface roughness. At higher microwave frequencies, conductor loss from surface roughness becomes significant. AD450 is typically available with standard microwave-grade copper foil. If you’re operating above 10–15 GHz and insertion loss is critical, discuss low-profile copper options with your fabricator.

Frequently Asked Questions About Arlon AD450

Q1: Can I use my existing FR-4 PCB design files directly with AD450 without redesigning trace widths?

In most cases, yes. With a Dk of 4.5, AD450 closely matches the dielectric constant of typical FR-4. Most transmission line structures and impedance-controlled traces will not require significant width adjustment. You should verify impedance with your fabricator’s specific stackup and confirm using a field solver, but the geometry change required is typically small — a practical advantage that was specifically engineered into AD450.

Q2: What frequencies is Arlon AD450 suitable for?

AD450 is suitable from low microwave through several GHz. Its stable Dk and low Df make it appropriate for applications in the UHF band through approximately 10 GHz and beyond for many circuit types. Exact upper frequency utility depends on your acceptable insertion loss budget and circuit geometry. For applications operating above 20–30 GHz, lower-Dk, lower-loss PTFE laminates may offer better performance.

Q3: How does AD450 compare to the older Arlon AR450?

AR450 used non-woven fiberglass reinforcement; AD450 uses woven fiberglass. The electrical performance targets are essentially the same (both aim for Dk ~4.5), but AD450 delivers better Dk uniformity across a panel, better dimensional stability, and lower manufacturing cost. Arlon designed AD450 specifically as AR450’s replacement, and the materials are considered functionally equivalent for most design purposes.

Q4: Is Arlon AD450 still available now that Rogers acquired Arlon?

Yes. Rogers Corporation completed its acquisition of Arlon’s electronic materials division, and AD450 remains part of the product portfolio. It may be listed under Rogers’ branding in some supplier catalogs. Lead times and availability can vary, so checking with your PCB fabricator or a Rogers-authorized distributor before final design lockdown is advisable.

Q5: What surface finishes work well with Arlon AD450?

ENIG (Electroless Nickel Immersion Gold) is the most commonly specified finish for AD450 in antenna and RF applications — it provides excellent coplanarity and consistent solderability without the oxidation issues of bare copper or HASL. OSP (Organic Solderability Preservative) is used in some commercial applications. For connectors and edge-launch applications, confirm finish compatibility with your connector supplier.

Summary

Arlon AD450 occupies a genuinely useful position in the laminate landscape: it delivers PTFE-based RF performance — stable Dk, low dissipation factor, good thermal behavior — at a dielectric constant specifically engineered to make FR-4 migration practical. For engineers dealing with designs that have outgrown FR-4’s frequency ceiling but where a Dk of 2.5 or 3.5 would require a full trace-geometry redesign, AD450’s 4.5 Dk is a practical path forward.

The ceramic filler adds thermal conductivity and reduces Z-axis CTE, making it a more reliable PTH substrate than standard PTFE laminates. The move to woven fiberglass reinforcement over the older AR450 tightened Dk uniformity and dimensional stability across a panel. Both are meaningful engineering improvements, not marketing language.

Whether you’re designing a wideband base station antenna, a multimedia system front-end, or upgrading a legacy FR-4 RF board to handle a new frequency band, AD450 is worth evaluating seriously as part of your material selection process.

Typical properties listed in this article are based on published Arlon datasheet information and should not be used as specification limits. Contact your Arlon/Rogers representative or authorized distributor for current specification data and fabrication guidance specific to your application.

Arlon AD vs DiClad: understand the real differences between ceramic-filled PTFE and pure fiberglass/PTFE laminates. Full comparison of electrical properties, CTE, PIM, and which series fits your application.

Picking the wrong laminate family for a high-frequency design is one of those mistakes that doesn’t always show up immediately. The board passes initial impedance testing, looks fine on the bench, and then degrades in the field over thermal cycling or starts causing PIM issues in a multi-carrier base station. When engineers ask “what’s the difference between the Arlon AD Series and the DiClad Series,” they’re usually asking because they’ve hit exactly this kind of wall.

This guide breaks down the Arlon AD vs DiClad comparison in practical terms — construction chemistry, electrical performance, processability, and which family actually makes sense for which type of design. Both series share PTFE-based roots, but the engineering decisions made in each are quite different, and those decisions have real consequences at the board level.

Understanding the Arlon Microwave Materials Lineage

Before diving into the comparison, it helps to understand where these materials sit in the broader Arlon ecosystem. Arlon Electronic Materials Division — now operating under Rogers Corporation following their acquisition — has over 50 years of experience in PTFE-based microwave laminates. The division is a major manufacturer of specialty high-performance laminate and prepreg materials, with applications spanning avionics, semiconductor testing, heat sink bonding, high-density interconnect, and microwave PCBs for mobile communication products.

Within Arlon’s microwave materials catalog, both the AD Series and DiClad Series are PTFE-based woven fiberglass composites, but they diverge significantly in construction. The AD Series introduces ceramic fillers into the matrix — which changes the performance profile substantially. The DiClad Series sticks to a purer fiberglass/PTFE composite without ceramic reinforcement. Understanding why that matters starts with the materials science.

What Is the Arlon DiClad Series?

DiClad Construction: Woven Fiberglass and PTFE

Rogers DiClad Series laminates are fiberglass-reinforced PTFE-based composites for use as printed circuit board substrates in high-frequency applications. The controlled fiberglass and PTFE content ratio enables DiClad laminates to offer a range of low dielectric constant (Dk) values. Higher PTFE content provides a lower Dk and loss tangent, while higher fiberglass content provides better dimensional stability and registration.

Unlike the CuClad laminate series, the DiClad laminates do not have cross-plied constructions. This is an important fabrication note: the fiberglass plies in DiClad materials are aligned in the same direction, which means the material behaves differently in X vs. Y from an expansion standpoint compared to the cross-plied CuClad alternatives.

DiClad Grades: 527, 870, and 880

The DiClad family covers three main substrate grades, each tuned to a different fiberglass/PTFE ratio:

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.

DiClad 870 uses a medium fiberglass/PTFE ratio for lower dielectric constant and improved dissipation factor without sacrificing mechanical properties. DiClad 880 uses a low fiberglass/PTFE ratio to provide the lowest dielectric constant in the series — Dk of 2.17 or 2.20 — with a correspondingly excellent dissipation factor of 0.0009 at 10 GHz.

DiClad laminates are frequently used in filter, coupler, and low noise amplifier applications where dielectric constant uniformity is critical. They are also used in power dividers and combiners where low loss is important.

DiClad Electrical Properties at a Glance

Grade	Dk (10 GHz)	Df (10 GHz)	Fiberglass/PTFE Ratio	Key Strength
DiClad 527	2.40–2.65	0.0017	High	Dimensional stability, mechanical toughness
DiClad 870	2.33	0.0013	Medium	Balanced Dk and Df
DiClad 880	2.17, 2.20	0.0009	Low	Lowest loss, lowest Dk in series

These numbers come directly from the Rogers/Arlon datasheet (IPC-TM-650 testing at 23°C, 50% RH). The DiClad 880’s Df of 0.0009 at 10 GHz represents one of the lowest loss values available in a woven fiberglass-reinforced PTFE laminate — which is why it earned its reputation in precision filters, couplers, and low-noise amplifier circuits.

What Is the Arlon AD Series?

AD Series Construction: The Three-Component Approach

This is where the Arlon AD vs DiClad comparison gets interesting. The AD Series doesn’t just use fiberglass and PTFE. The AD250C, AD255C, and AD260A microwave high-frequency PCB materials leverage a cost-efficient blend of composite chemistry and architecture, integrating the excellent thermal properties of fluoropolymer resin systems with carefully selected ceramic materials and glass fiber reinforcements.

The addition of micro-dispersed ceramic filler is the defining engineering decision that separates the AD Series from the DiClad family. Ceramics change the thermal behavior of the laminate in ways that pure fiberglass/PTFE composites cannot achieve. The addition of differential dispersion ceramics provides thermal stability in the form of lower CTE and higher temperature phase stability.

The Three Generations of AD Series Laminates

Understanding the suffix designations on AD Series products explains a lot about their evolution. According to Cirtech Electronics’ detailed product history, the first-generation AD Series products used the ‘L’ designation, built from PTFE and woven fiberglass for lower Dk options in the 2.50–3.50 range. The ‘A’ designation followed, introducing ceramic-filled layers to replace some unfilled resin layers — reducing cost, Z-axis expansion, and dissipation factor simultaneously. The ‘C’ designation represents the current third generation, pushing ceramic content further to reduce Z-axis expansion and Df even further while maintaining cost efficiency.

These advanced materials are distinguished by their low dielectric constants, cost-effectiveness, and exceptional low-loss characteristics, making them highly suitable for modern telecommunications infrastructure.

AD Series Grades

Grade	Dk (10 GHz)	Df (10 GHz)	Dk Tolerance	Primary Use
AD250C	2.50	0.0014	±0.04	Low-cost telecom antenna boards
AD255C	2.55	0.0013	±0.04	Base station antennas, 5G feeds
AD260A	2.60	0.0014	±0.04	Antenna arrays, commercial wireless
AD300C/D	3.00	~0.002	Controlled	Higher Dk antenna systems
AD350A	3.50	~0.003	Controlled	Compact antenna applications

The tightly controlled Dk tolerances (±0.04) across the series are critical for antenna manufacturing at volume. These AD Series materials ensure consistent antenna performance and reliable operation, with ultra-low PIM values as low as -165 dBc, ensuring minimal signal interference.

Arlon AD vs DiClad: Direct Comparison

Core Chemistry Differences

Property	DiClad Series	AD Series
Resin System	PTFE	PTFE + micro-dispersed ceramic
Reinforcement	Woven fiberglass only	Woven fiberglass + ceramic fillers
Construction	Single-direction ply alignment	Standard layup
Generations	Mature, stable product line	Three generations (L, A, C)
Cross-plied option	No (CuClad is the cross-plied variant)	No

Electrical Performance Comparison

The most significant electrical difference between the two series is the loss tangent floor and the dielectric constant range each covers.

DiClad 880, at Df = 0.0009 at 10 GHz, achieves the lowest loss of any material in either family. This is possible because of the high PTFE content in the 880 grade — PTFE itself has naturally very low loss, and maximizing its proportion in the matrix minimizes dielectric losses. The AD Series’ Df of 0.0013–0.0014 at 10 GHz is still excellent by any standard, but it doesn’t quite reach the floor that a low-fiberglass PTFE laminate like DiClad 880 can achieve.

On the other hand, the AD Series’ tighter Dk tolerance and better thermal Dk stability give it an advantage in broadband, temperature-varying applications. The ceramic fillers compensate for PTFE’s negative temperature coefficient of dielectric constant — meaning the AD Series’ Dk stays more stable across the operating temperature range than a pure fiberglass/PTFE composite.

Performance Factor	DiClad 880 Winner	AD255C Winner
Absolute lowest Df	✓	—
Dk stability over temperature	—	✓
PIM performance	Competitive	✓ (specified)
Dk range (low end)	✓ (2.17)	2.50 minimum
Cost efficiency at volume	—	✓
Phase stability across temperature	Good	Better

Dimensional Stability and CTE

This is one of the clearer advantages of the AD Series. The AD Series’ low Z-axis thermal expansion significantly improves the reliability of plated through-hole (PTH) connections compared to typical PTFE base materials. Additionally, low X-Y expansion enhances the reliability of BGA solder joints.

The ceramic fillers essentially act as a thermal expansion moderator. PTFE itself has a relatively high CTE, and when you’re running PTH barrel through many thermal cycles, that Z-axis expansion can fatigue the copper barrel plating. The AD Series’ ceramic loading brings the Z-CTE down toward copper’s expansion rate, reducing the mechanical stress at each thermal cycle. For DiClad materials, particularly the 880 grade with its high PTFE content, this trade-off is accepted in exchange for the superior low-loss electrical performance.

Passive Intermodulation (PIM) Performance

PIM performance is a distinguishing factor that almost never comes up when engineers are designing filters or couplers, but becomes absolutely central to antenna design. AD255C is the third-generation commercial microwave and RF laminate material designed with low dielectric, low cost and excellent low-loss characteristics, built on a cost-effective combination for CTE values and greater phase stability across temperatures.

The AD Series explicitly targets PIM-sensitive applications. Reverse-treated ED copper is recommended for reduced PIM performance, and some grades offer a “PIM+” performance option. The DiClad series, while a capable microwave laminate, was not specifically developed with PIM minimization as a primary design target — it was optimized for the filter, coupler, and LNA market where insertion loss and Dk uniformity dominate the design requirements.

Which Series for Which Application?

When to Choose Arlon DiClad

DiClad 880 is your material when you need the lowest possible insertion loss and your Dk requirement falls in the 2.17–2.20 range. Precision microwave filters, couplers, and power dividers benefit most from this material’s Df = 0.0009 performance. If you’re building a combiner network for a high-power radar or a low-noise downconverter where every tenth of a dB matters, DiClad 880 is hard to beat in the woven fiberglass PTFE category.

DiClad 527 is the workhorse for applications where you need mechanical robustness in a low-Dk PTFE-based material. Its higher fiberglass/PTFE ratio provides dimensional stability that makes fabrication more predictable — tighter tolerance on layer-to-layer registration in multilayer builds, better resistance to the creep and cold-flow behavior that can plague high-PTFE-content materials.

DiClad 527 is used in military radar feed networks, commercial phased array networks, low-loss base station antennas, missile guidance systems, digital radio antennas, and filters, couplers, and LNAs.

When to Choose Arlon AD Series

The AD Series was built around the telecom infrastructure market, particularly base station antenna manufacturing at commercial volumes. If your design requirements include:

• Multi-carrier antenna systems where PIM is a specified limit
• Large-panel, high-volume production where per-panel cost matters
• Applications with wide ambient temperature swings where Dk stability is critical
• 5G base station feed networks and distributed antenna systems
• Designs using BGA or other area-array components that are sensitive to X-Y CTE mismatch

…then the AD Series is the natural fit. The higher weight ratio of fiberglass to PTFE resin in the AD Series yields laminates with greater dimensional stability than is normally expected of PTFE-based substrates. The stability of PTFE over a wide frequency range and low loss makes AD Series materials ideal for a variety of microwave and RF applications in the telecom industry.

Application Summary Table

Application	Recommended Series	Grade
Precision microwave filters	DiClad	880
Low-noise amplifier circuits	DiClad	880, 870
Power dividers and combiners	DiClad	870, 880
Multilayer RF with tough PTH requirements	DiClad	527
Base station panel antennas	AD Series	AD255C, AD250C
5G multi-band antenna systems	AD Series	AD255C
Automotive radar (volume)	AD Series	AD255C, AD260A
High Dk antenna miniaturization	AD Series	AD300, AD350A
Phased array feeds (precision)	DiClad or AD	527 or AD255C

Fabrication Considerations for Both Series

Both series share PTFE-based processing requirements that differ meaningfully from standard FR-4 work. Arlon’s PTFE laminates are fiberglass/PTFE resin composites used in high-frequency applications where low loss and controlled dielectric constant are required. Using precise control of the resin-to-glass ratio, Arlon is able to offer a range of materials from the lowest dielectric constant and dissipation factor to more highly reinforced laminate having better dimensional stability.

Key fabrication notes that apply to both series:

Surface preparation before lamination is non-negotiable with PTFE materials. Chemical etching or plasma treatment of PTFE surfaces is required for adequate adhesion. Standard FR-4 oxide treatments are not suitable.

Drilling requires PTFE-appropriate parameters — high chip load to avoid smearing, entry and backup materials selected for PTFE, and tooling life management. The ceramic fillers in the AD Series can reduce drill bit life compared to non-ceramic DiClad grades — confirm tooling parameters with your fabricator.

Copper adhesion requires proper surface microstructure. Avoid mechanical scrubbing after etching, which can destroy the micro-roughness needed for bond quality.

AD255C is compatible with the processing used for standard PTFE-based printed circuit board substrates. Its low Z-axis thermal expansion improves plated through-hole (PTH) reliability compared to typical PTFE-based laminates. Low X-Y expansion improves BGA solder-joint reliability.

For production of Arlon PCB designs using either series, working with a fabricator who has documented PTFE process experience is essential. The process sensitivities are real, and fabricators who primarily work in FR-4 often underestimate the differences.

Useful Resources for Engineers

Resource	Description	Link
Rogers AD Series Product Page	Official spec and download page (AD250C, AD255C, AD260A, AD300D, AD350A)	rogerscorp.com
AD Series Datasheet (PDF)	Full electrical, mechanical, and thermal properties	Rogers AD Series PDF
Rogers DiClad Series Product Page	Official product page with DiClad 527, 870, 880	rogerscorp.com
DiClad Series Datasheet (PDF)	Full electrical, mechanical, thermal and panel data	Rogers DiClad PDF
Rogers Laminate Properties Tool	Interactive online selector for comparing all Rogers/Arlon laminates	tools.rogerscorp.com
Arlon Laminate Guide (PDF)	Arlon’s own guide covering DiClad, CuClad, AD Series and material selection	arlonemd.com
Rogers High Frequency Product Selector Guide	Full portfolio guide across all Rogers high-frequency materials	Available on Rogers downloads page
MatWeb – AD255C Entry	Third-party material properties database	matweb.com

Frequently Asked Questions: Arlon AD vs DiClad

1. Can I use DiClad as a drop-in replacement for AD Series in an antenna design?

Not without re-evaluating your design. The DiClad series doesn’t offer grades in the 2.50–3.50 Dk range that the AD Series covers — the DiClad materials sit at Dk 2.17 to 2.65. If your antenna is designed around a specific Dk value, substituting a different Dk will shift your resonant frequency and impedance. Additionally, the AD Series’ better Dk-vs.-temperature stability and lower PIM make it more predictable in production antenna environments. You’d need to re-simulate and re-qualify the design if switching between the two families.

2. Which series has better loss tangent performance at mmWave frequencies?

DiClad 880 holds the advantage at the very low loss end, with Df = 0.0009 at 10 GHz. At mmWave frequencies (above 30 GHz), the dielectric loss contribution grows significantly, making this advantage more meaningful. For sub-6 GHz 5G and typical microwave applications below 20 GHz, the AD Series’ Df = 0.0013 is still excellent and provides better overall system value when PIM and CTE requirements are factored in. For 28 GHz and above designs where every fraction of a dB in dielectric loss matters, DiClad 880 or an alternative ultra-low-loss material should be your starting point.

3. Why does the AD Series cost less than some comparable DiClad grades?

The AD Series was specifically engineered for cost efficiency. Each generation (L → A → C) progressively replaced higher-cost unfilled PTFE resin layers with lower-cost ceramic-filled layers, while actually improving the thermal and electrical properties in the process. The ceramic fillers are cheaper than an equivalent volume of unfilled PTFE. For high-volume antenna manufacturing, this cost optimization was a deliberate commercial decision aligned with the telecom industry’s price sensitivity. DiClad 880, by contrast, maximizes PTFE content to achieve its loss floor — which uses more of the expensive unfilled PTFE resin and is produced in a narrower market volume.

4. Is the DiClad series available as a multilayer stackup material?

Yes, but with an important caveat. DiClad laminates are used in multilayer builds, but the bonding film selection is critical. Compatible Rogers/Arlon bondplies such as CuClad 6700 or CuClad 6250 are required to maintain the dielectric continuity of the stack. The lack of a cross-plied construction in DiClad (unlike CuClad, which offers cross-plied versions of similar materials) means that dimensional stability in multilayer registration needs more careful process management. The AD Series has better dimensional stability from its ceramic loading and is generally considered more forgiving in multilayer constructions.

5. How do I verify which Arlon material grade I’ve received from a distributor?

Request the Certificate of Conformance (CoC) and material test report from your distributor. Authentic Rogers/Arlon materials come with traceable lot numbers and test data. For critical performance applications, Rogers’ “LX” testing grade option (available on CuClad and some other Arlon products) provides individual sheet test data — confirm with your distributor or Rogers directly whether this option is available for your specific grade. If you have doubts about material authenticity or lot consistency, Rogers Corporation’s technology support hub provides technical assistance for material verification.

Summary: AD Series vs DiClad Series at a Glance

The Arlon AD vs DiClad choice ultimately comes down to what your design is optimizing for. The DiClad series — particularly the 880 grade — is built for engineers who need the absolute lowest dielectric loss in a woven fiberglass PTFE laminate, prioritizing precision microwave performance over volume cost and thermal expansion management. The AD Series is built for engineers designing antenna systems and RF infrastructure at commercial scale, where PIM control, Dk stability over temperature, processability at volume, and per-panel cost all matter alongside the core RF performance.

Neither series is universally superior. A precision microwave filter designer and a base station antenna engineer are asking different questions of their substrate — and Arlon/Rogers designed each series to answer a different set of those questions. Pick your material to match your application, not your habit.

Arlon AD350A: Dk 3.50, Df 0.0030 PTFE laminate — full specs, datasheet, fabrication tips, and applications in 5G, radar, satellite, and defense RF systems.

There’s a particular category of design problem that keeps RF engineers up at night: the gap between what low-loss PTFE substrates can deliver electrically and what production environments can actually handle reliably. Pure PTFE laminates like RT/duroid 5880 sit at one extreme — outstanding RF properties, terrible dimensional stability, and fabrication that punishes any shop without specialized PTFE process capability. Standard hydrocarbon-ceramic materials like RO4003C sit at the other — easy to fab, but with a dielectric constant above 3.5 and higher loss than many designs can absorb at millimeter-wave frequencies. The Arlon AD350A lives in a carefully engineered middle ground, and understanding exactly where it excels — and where it has limitations — is what this article is about.

What Is Arlon AD350A?

The Arlon AD350A is a PTFE/woven glass composite laminate designed for RF, microwave, and millimeter-wave printed circuit board applications. It is part of the AD Series of high-frequency laminates originally developed by Arlon Electronic Materials, now under the Rogers Corporation Advanced Electronics Solutions portfolio following Rogers’ 2019 acquisition of Arlon.

The “350” in the designation reflects its nominal dielectric constant: Dk = 3.50. This positions the AD350A distinctly within the AD product family — higher dielectric constant than the ultra-low-Dk AD255C (Dk 2.55), but offering the benefit of tighter, more compact circuit geometries at a given frequency. For engineers designing filters, couplers, and patch antennas where board real estate is at a premium, that higher Dk translates directly into smaller feature dimensions.

The “A” suffix indicates its specific formulation: a PTFE matrix reinforced with woven fiberglass cloth, loaded with ceramic particles to improve dimensional stability and mechanical robustness versus pure or microfiber-filled PTFE alternatives. This combination gives the AD350A its characteristic balance of good RF performance and practical manufacturability.

Where the AD350A slots into real designs is in applications needing a Dk near 3.5 with lower loss than RO4350B or standard hydrocarbon laminates, paired with the environmental stability of a PTFE-based system — particularly in outdoor, airborne, or high-humidity field environments where epoxy-based substrates absorb moisture and drift in their electrical properties.

Arlon AD350A Full Electrical Properties

The electrical performance data below reflects values measured using IPC-TM-650 standardized test methods. Engineers should always download the current official datasheet (linked in the Resources section below) to confirm values for their specific design revision, as specifications can be updated.

Electrical Property	Value	Test Condition / Method
Dielectric Constant (Dk)	3.50 ± 0.05	IPC-TM-650 2.5.5.5 @ 10 GHz
Loss Tangent (Df)	0.0030	IPC-TM-650 2.5.5.5 @ 10 GHz
Dielectric Constant Stability vs. Frequency	Excellent — flat through millimeter-wave	Broadband measurement
Volume Resistivity	>10⁹ MΩ·cm	IPC-TM-650 2.5.17.1
Surface Resistivity	>10⁷ MΩ	IPC-TM-650 2.5.17.1
Dielectric Breakdown Voltage	>1,000 V/mil	ASTM D149
Relative Permittivity @ 1 MHz	~3.55	Lower-frequency measurement

The loss tangent of 0.0030 at 10 GHz is where engineers need to make an honest assessment against their application. For comparison, FR-4 runs 0.020–0.025 — roughly seven to eight times worse. Against hydrocarbon-ceramic alternatives like RO4350B (Df 0.0037 at 10 GHz), the AD350A holds a measurable edge. Against the lower-Dk sibling AD255C (Df 0.0019), the AD350A is higher in loss — the trade-off you accept for a more compact design footprint at the same impedance.

The Dk tolerance of ±0.05 is tight enough for production impedance control. Microstrip line width calculation is directly proportional to Dk; a ±0.05 variation on a Dk of 3.50 corresponds to roughly ±0.7% Dk variance — well within the tolerance that allows consistent 50-ohm line fabrication across an 18×24-inch panel.

Arlon AD350A Mechanical and Thermal Properties

PTFE-based laminates have historically carried a reputation for mechanical fragility and difficult processing. The woven glass reinforcement and ceramic loading in the AD350A’s construction addresses most of those concerns directly.

Mechanical / Thermal Property	Value	Test Method
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	~25 ppm/°C	IPC-TM-650 2.4.41
Thermal Conductivity	~0.21 W/m·K	ASTM C518
Glass Transition Temperature (Tg)	>260°C (PTFE matrix)	DSC
Decomposition Temperature (Td)	>260°C	TGA
Moisture Absorption	<0.10%	IPC-TM-650 2.6.2
Density	~2.20 g/cm³	—
Tensile Strength (X/Y)	~100 MPa	IPC-TM-650 2.4.18
Copper Peel Strength (1 oz ED Cu)	>5 lb/inch	IPC-TM-650 2.4.8
Flexural Strength	~110 MPa	IPC-TM-650 2.4.4
Flammability Rating	UL 94 V-0	UL 94

The z-axis CTE of approximately 25 ppm/°C compares favorably to unfilled PTFE substrates, which can exceed 150 ppm/°C in the z-direction. This level of z-axis dimensional stability is what makes reliable through-hole and blind via construction possible over repeated thermal cycles — a critical consideration for assemblies that will see solder reflow and field operating temperature swings.

The moisture absorption below 0.10% is one of the strongest arguments for choosing any PTFE-based laminate over epoxy alternatives in outdoor or high-humidity applications. When moisture absorption is high (FR-4 can absorb 0.10–0.20% or more), the effective Dk of the material shifts with ambient humidity. A Dk shift of even 0.05 causes measurable impedance deviation that manifests as return loss degradation — exactly the kind of gradual in-service performance drift that is frustratingly difficult to root-cause in deployed hardware.

Available Configurations and Panel Formats

The AD350A is offered across a range of dielectric thicknesses and copper configurations to support both single/double-sided and multilayer PCB constructions.

Parameter	Available Options
Dielectric Thickness	5 mil (0.127 mm), 10 mil (0.254 mm), 20 mil (0.508 mm), 30 mil (0.762 mm), 60 mil (1.524 mm), 125 mil (3.175 mm)
Copper Weight	½ oz/ft² (17 µm), 1 oz/ft² (35 µm), 2 oz/ft² (70 µm)
Copper Type	Electrodeposited (ED), Rolled Annealed (RA)
Panel Size	Standard 18″ × 24″; custom dimensions available on request
Cladding Configuration	Single clad (1-sided), double clad (2-sided)
Reinforcement Type	Woven PTFE/ceramic composite glass fabric

For most microwave designs operating between 5 GHz and 40 GHz, 10 mil and 20 mil dielectric thicknesses represent the most frequently specified options. Thinner substrates reduce surface wave effects and support narrower feature widths for compact filter and coupler designs.

Rolled annealed (RA) copper is worth specifying when operating above 30 GHz. The smoother surface profile of RA copper — compared to electrodeposited (ED) copper’s rougher nodular surface — reduces skin-effect-driven conductor loss at frequencies where skin depth approaches the scale of surface roughness features. At E-band (71–86 GHz), this distinction can be worth 0.3–0.5 dB/cm of insertion loss reduction.

Arlon AD350A vs. Competing High-Frequency Laminates

Selecting the AD350A in isolation doesn’t tell you much. The useful question is always: compared to what? Here is an honest side-by-side with the materials you’re most likely considering for the same design slot.

Material	Dk @ 10 GHz	Df @ 10 GHz	Z-axis CTE (ppm/°C)	Construction	Notes
Arlon AD350A	3.50	0.0030	~25	PTFE/woven glass/ceramic	Balanced RF + fab
Arlon AD255C	2.55	0.0019	24	PTFE/woven glass/ceramic	Lower loss, lower Dk
Rogers RO4350B	3.48	0.0037	32	Hydrocarbon/ceramic	No PTFE, easier fab
Rogers RO4003C	3.55	0.0027	46	Hydrocarbon/ceramic	Lower loss, higher z-CTE
Taconic RF-35	3.50	0.0018	~40	PTFE/ceramic	Lower loss than AD350A
Rogers RT/duroid 6002	2.94	0.0012	16	PTFE/ceramic	Very low loss, low z-CTE
FR-4 (standard)	4.3–4.8	0.020–0.025	70	Epoxy/woven glass	Not suitable above ~1 GHz

A few relationships from this table deserve specific comment.

AD350A vs. RO4350B: The AD350A wins on loss tangent (0.0030 vs. 0.0037) and moisture stability. RO4350B wins on ease of fabrication — it can be processed in standard epoxy shops without PTFE-specific via preparation. For designs where fabrication simplicity and cost matter more than the last fraction of a dB in insertion loss, RO4350B often wins in practice. When you need PTFE-grade moisture performance and slightly lower Df, the AD350A earns its place.

AD350A vs. RO4003C: RO4003C has a slightly lower Df (0.0027) but a much higher z-axis CTE (46 vs. 25 ppm/°C), which creates via reliability challenges in thick multilayer designs with many thermal cycles. The AD350A’s superior z-axis stability makes it a better choice for thick boards or assemblies operating across wide temperature ranges.

AD350A vs. Taconic RF-35: Both have Dk = 3.50. The RF-35 achieves a lower Df of 0.0018, which is a meaningful advantage in long transmission lines or high-Q filter applications. However, availability, pricing, and regional supplier networks can make the AD350A the more practical procurement choice depending on geography.

AD350A vs. AD255C: Same manufacturer, same construction family, meaningfully different electrical profile. If your design can tolerate the larger feature geometries that come with Dk 2.55 — wider microstrip lines, larger patch antenna elements — the AD255C’s lower Df gives better overall link budget. If board real estate drives you to Dk 3.5, the AD350A is the PTFE-family choice.

How to Fabricate Arlon AD350A PCBs: Process-Critical Notes

PTFE laminates require specific fabrication processes that standard FR-4 shops may not support. Getting this wrong produces via failures and delamination that are expensive and slow to diagnose. Here is what you need to verify with your fabricator before releasing a board built on AD350A.

Through-Hole and Via Preparation — The Most Critical Step

PTFE is chemically inert. Standard permanganate desmear processes used for epoxy laminates will not activate PTFE surfaces for electroless copper adhesion. For reliable via barrel plating, the fabricator must use one of two proven activation approaches:

Sodium naphthalene (sodium etch): A chemical process that selectively attacks the fluoropolymer surface, creating polar groups that allow electroless copper to bond effectively. This remains the most widely used method for PTFE laminates in production environments.

Plasma etching: An increasingly preferred alternative, particularly in shops operating to modern environmental standards. Oxygen/nitrogen or CF₄-based plasma physically and chemically activates the hole wall surface without the hazardous chemical handling requirements of sodium naphthalene. Results are comparable when process parameters are well controlled.

Inadequate surface activation produces barrel plating that looks fine during initial board inspection but fails through thermal cycling as the copper-to-PTFE adhesion breaks down. This is one of the most common failure modes in PTFE PCB assemblies fabricated in shops without proper PTFE experience.

Drilling Parameters

PTFE’s relatively low modulus and tendency to cold-flow under heat requires careful attention to drill speed, feed rate, and tooling sharpness. Use sharp carbide drill bits with feed rates appropriate for PTFE composites — not the FR-4 drill parameters that most automated drill machines default to. Dull tooling generates heat that smears PTFE onto the hole wall, creating an even more difficult surface for subsequent plating activation.

Diamond-coated drill bits extend tool life significantly in production runs and produce cleaner hole walls with less PTFE smear.

Etching and Line Definition

Standard copper etchants (ferric chloride, ammonium persulfate, cupric chloride) work well with AD350A. The material’s smooth surface finish allows fine-line geometries to be achieved with good repeatability. For designs with sub-5 mil line widths, discuss etch factor compensation with your fabricator early — the PTFE surface’s low surface energy can occasionally cause minor adhesion effects that influence etch uniformity on very fine features.

Assembly and Soldering

The AD350A’s PTFE matrix handles standard lead-free reflow soldering profiles (peak temperatures 255–260°C) without laminate damage. The UL 94 V-0 flammability classification is maintained after assembly. For wave soldering applications, use flux systems compatible with PTFE-based substrates, as some flux chemistries can interact with PTFE surfaces at elevated temperatures.

For a broader look at how these process requirements apply across Arlon’s product range, the Arlon PCB material overview covers fabrication considerations that apply across the AD Series family.

Arlon AD350A Applications: Where It Gets Specified

The AD350A’s combination of Dk 3.50, Df 0.0030, and PTFE-grade environmental stability defines a specific application space. Here is where engineers most commonly reach for it.

5G Wireless Infrastructure

Sub-6 GHz 5G base station hardware — antennas, combiners, diplexers, and power dividers in the 3.4–3.8 GHz and 4.9–5 GHz bands — benefits from a substrate with low insertion loss and stable performance over the outdoor temperature and humidity cycles that base station equipment endures year-round. The AD350A’s moisture absorption below 0.10% ensures the Dk and Df stay within specification in the humid coastal and tropical environments where 5G deployment has expanded rapidly.

Microwave Filters and Diplexers

Bandpass filters, duplexers, and multiplexers designed in coupled-resonator topologies (hairpin, interdigital, combline) benefit from a substrate with predictable, consistent Dk to hit center frequency and rejection specifications in production. The AD350A’s tight ±0.05 Dk tolerance and flat Dk-vs.-frequency characteristic through 40 GHz make it a strong candidate for this class of design, particularly in the 6–40 GHz frequency range.

Radar Front-End Assemblies

Ground-based surveillance radars and airborne weather radars operating in the X-band (8–12 GHz) and Ku-band (12–18 GHz) frequency ranges have demanding insertion loss budgets. Radar receive chains need to preserve as much signal-to-noise ratio as possible before the first amplifier stage, which means substrate loss directly impacts minimum detectable signal performance. The AD350A’s Df of 0.0030 provides acceptable insertion loss performance for these systems while delivering the environmental stability that outdoor and airborne equipment requires.

Satellite Communication Ground Terminals

Ku-band and Ka-band satellite modem hardware, earth station feed networks, and low-noise block downconverter PCBs are natural applications for the AD350A. The combination of low moisture absorption and good thermal stability ensures that outdoor-mounted satellite receive equipment maintains calibrated performance across seasonal temperature swings and weather cycles.

Defense and Avionics Electronic Systems

Electronic warfare (EW), SIGINT, and communications-on-the-move (COTM) systems specify laminate materials based on a combination of RF performance, environmental robustness, and compliance with military materials specifications. The AD350A’s PTFE construction, UL 94 V-0 rating, and low moisture absorption align well with these requirements. Its dimensional stability over the −55°C to +125°C operating range typical of mil-spec hardware is a meaningful advantage over epoxy-based substrates.

High-Power RF Applications

Moderate-to-high RF power applications — power amplifier output networks, high-power combiners, and transmission line sections carrying significant RF power — benefit from the AD350A’s ability to handle elevated temperatures without laminate damage. PTFE’s inherently high decomposition temperature (above 260°C) provides margin against localized hot spots that can develop in high-power passive circuitry.

Useful Resources for Arlon AD350A

Engineers specifying or evaluating the AD350A should use the following reference resources. Manufacturer datasheets should always be consulted directly rather than relying on third-party reproductions, which may contain outdated values.

Resource	Description	Where to Access
Arlon AD350A Official Datasheet	Full property tables, dimensional data, and test conditions	Rogers Corp Document Library at rogerscorp.com
Rogers Corp AD Series Product Page	Full AD Series family comparison and selector tools	rogerscorp.com/advanced-electronics-solutions
IPC-4103 Specification	Industry standard for high-frequency/high-speed laminates covering PTFE materials	ipc.org
IPC-TM-650 Test Methods Manual	Standardized test procedures referenced in the AD350A datasheet (Dk, Df, moisture absorption, peel strength, CTE)	ipc.org/test-methods
Rogers Design Support Hub	Online impedance calculators for microstrip, stripline, and CPW using AD Series material properties	rogerscorp.com — Design Support Hub
IPC-2221 PCB Design Standard	General design standard relevant to controlled-impedance PCB layout practices	ipc.org
ASSIST QuickSearch (MIL Specs)	Military laminate specifications applicable to defense procurement of PTFE laminates	quicksearch.dla.mil

Always verify that you are accessing the most current datasheet revision. Arlon material specifications have been periodically updated under Rogers Corporation stewardship, and older versions circulating in cached PDFs or third-party databases may contain superseded Df values that differ from current production material.

5 Frequently Asked Questions About Arlon AD350A

Q1: What is the dielectric constant of Arlon AD350A, and why does a Dk of 3.5 matter for circuit design?

The nominal dielectric constant of AD350A is 3.50 ± 0.05, measured at 10 GHz. The practical significance of Dk 3.50 versus lower-Dk materials is straightforward: for a given transmission line impedance, higher Dk produces physically narrower lines and smaller component geometries. A 50-ohm microstrip on AD350A is roughly 20–25% narrower than on an AD255C (Dk 2.55). For dense circuit layouts — multi-element filter banks, compact beamforming networks, and packaged modules — that geometry reduction can be a decisive design enabler. The trade-off is slightly higher phase velocity dispersion compared to lower-Dk PTFE substrates.

Q2: Can Arlon AD350A be fabricated at a standard FR-4 PCB shop?

Not reliably. The critical issue is through-hole and via preparation. PTFE will not bond to electroless copper through standard permanganate desmear processes. Your fabricator must use either sodium naphthalene chemical etching or plasma activation before electroless copper deposition, or you will get via barrel adhesion failures that manifest as intermittent opens during thermal cycling in the field. Shops experienced in Rogers, Taconic, or Arlon PTFE materials will have these processes qualified. Verify this explicitly before placing an order — not all shops advertising “high-frequency PCB capability” have genuine PTFE process qualification.

Q3: How does Arlon AD350A perform in outdoor and high-humidity environments?

This is one of the strongest use cases for the AD350A. Its moisture absorption below 0.10% means that the dielectric constant and loss tangent remain stable in high-humidity field conditions. By comparison, FR-4 and many epoxy-based laminates can absorb 0.10–0.20% or more of moisture by weight, causing the effective Dk to drift measurably. For outdoor base station antennas, satellite ground terminals, and shipboard radar hardware that will spend years in humid environments, PTFE’s inherent hydrophobicity is a genuine performance and reliability advantage.

Q4: What frequency range is the Arlon AD350A rated for?

The AD350A is suitable across an extremely wide frequency range. Its flat Dk-vs.-frequency characteristic makes it valid from low microwave (L-band, S-band) through Ka-band (26–40 GHz) and beyond at reduced substrate thicknesses. For millimeter-wave applications above 40 GHz, the Df of 0.0030 begins to contribute meaningful insertion loss per centimeter compared to lower-loss materials like AD255C or RT/duroid 6002. At these frequencies, evaluate the link budget carefully and consider whether the geometry benefit of Dk 3.5 justifies the additional loss relative to alternatives.

Q5: Is Arlon AD350A compatible with lead-free assembly and RoHS requirements?

Yes on both counts. The AD350A is RoHS compliant. Its PTFE matrix has a decomposition temperature above 260°C, making it fully compatible with lead-free reflow soldering profiles that typically peak at 255–260°C. The UL 94 V-0 flammability rating is maintained through standard assembly processes. For assemblies involving multiple reflow passes (common in double-sided SMT), there are no special restrictions beyond the standard care needed with any PTFE laminate to avoid mechanical stress during thermal excursions on thick-format boards.

Selecting Arlon AD350A: The Honest Engineer’s Assessment

The AD350A is not the right answer for every high-frequency design — no single laminate is. What it offers is a very specific combination: PTFE environmental stability, Dk 3.50 for compact geometries, and Df 0.0030 that beats most hydrocarbon-ceramic alternatives — delivered in a woven-glass-reinforced construction that is meaningfully more manufacturable than unfilled PTFE.

If your design is in a moisture-challenged environment, needs a Dk near 3.5 for compact feature sizing, and can’t tolerate the higher loss tangent of RO4350B — or if you need the better z-axis CTE of a PTFE system versus the 46 ppm/°C of RO4003C — the AD350A sits in a real and useful specification space.

The friction point, as with all PTFE materials, is fabrication process control. Budget for the additional qualification conversation with your fabricator, specify PTFE-qualified via preparation on your fab drawing notes, and you will get reliable boards. Cut corners on that process step and the failures will follow — usually after the product is already in the field.

For engineers evaluating the full Arlon AD Series alongside other Rogers Corporation materials, a head-to-head material selection review with application-specific insertion loss modeling is time well

spent before committing a design to a substrate.

Suggested Meta Descriptions

Full version (~305 characters): Arlon AD350A PCB laminate: complete technical guide covering Dk 3.50, Df 0.0030, mechanical properties, datasheet specs, fabrication requirements, and real-world applications in 5G, radar, satellite, and defense microwave systems. Written from a PCB engineer’s perspective.

Condensed version for Yoast (156 characters): Arlon AD350A: Dk 3.50, Df 0.0030 PTFE laminate — full specs, datasheet, fabrication tips, and applications in 5G, radar, satellite, and defense RF systems.

Arlon AD300 laminate review covering dielectric constant, dissipation factor, thermal specs, and PCB design considerations. Includes comparison tables vs. Rogers and Taconic, PTFE fabrication tips, multilaye.

If you’re designing RF or microwave PCBs above a few gigahertz, your material selection stops being a footnote and becomes a core design variable. The laminate defines your insertion loss, your impedance stability over temperature, your reliability through assembly, and ultimately whether your design performs in the field or drifts out of spec the moment the enclosure heats up. Arlon AD300 sits in the category of ceramic-filled PTFE laminates specifically engineered for those demanding applications — and it has a track record in aerospace, defense, and high-frequency commercial electronics that’s worth understanding in detail before you commit to a stack-up.

This article covers everything a working PCB engineer needs to evaluate Arlon AD300: the full electrical and mechanical specifications, how it compares to competing materials, the practical design and fabrication considerations that don’t always make it into the datasheet, and the applications where it earns its cost premium.

What Is Arlon AD300?

Arlon AD300 is a ceramic-filled polytetrafluoroethylene (PTFE) composite laminate manufactured by Arlon Electronic Materials, a division of Arlon Group. It belongs to Arlon’s AD-series of high-frequency laminates, which are designed as direct competitors to the Rogers RT/duroid and RO-series materials commonly specified in microwave PCB design.

The AD300 designation reflects its nominal dielectric constant of 3.0, which places it in a useful mid-range position for microstrip and stripline impedance designs — high enough to allow compact transmission line geometries, low enough to maintain reasonable bandwidth and avoid excessive dispersion at millimeter-wave frequencies.

The material uses a woven PTFE base reinforced with ceramic filler particles. The ceramic loading is what controls the dielectric constant and improves dimensional stability compared to unfilled PTFE, while the PTFE matrix provides the low dissipation factor that makes the material suitable for low-loss RF transmission.

Arlon PCB laminates span multiple product families, and understanding where the AD300 fits within the broader lineup helps when evaluating alternatives for a given application.

Arlon AD300 Key Electrical Specifications

These are the parameters that drive RF performance. All values are from Arlon’s published datasheet and should be confirmed against the most current revision before design sign-off.

Parameter	Value	Test Condition / Notes
Dielectric Constant (Dk)	3.0 ± 0.04	10 GHz, IPC-TM-650 2.5.5.5
Dissipation Factor (Df)	0.0014	10 GHz
Dielectric Constant (Dk)	3.02	1 MHz
Dissipation Factor (Df)	0.0016	1 MHz
Dielectric Breakdown Voltage	> 1000 V/mil
Volume Resistivity	> 10⁸ MΩ·cm
Surface Resistivity	> 10⁷ MΩ
Moisture Absorption	< 0.02%	24hr immersion

The Dk of 3.0 is tightly controlled to ±0.04 across the panel. That level of consistency matters for phased array and filter designs where impedance matching tolerances are tight. Loose Dk variation translates directly to impedance variation in fabricated transmission lines, which becomes a yield and performance problem at scale.

The dissipation factor of 0.0014 at 10 GHz is the headline number. To put that in context: FR-4 runs a Df of roughly 0.020 at 1 GHz — more than ten times higher. At 10 GHz, FR-4’s loss tangent climbs further and becomes essentially unusable for any transmission line application beyond a few centimeters. AD300’s Df remains stable into the millimeter-wave region, which is the core value proposition of the material.

Arlon AD300 Mechanical and Thermal Specifications

Electrical performance at room temperature is only part of the story. For RF hardware that lives in an automotive under-hood environment, a radar housing on an aircraft, or a base station exposed to thermal cycling, the mechanical stability of the substrate through temperature extremes matters just as much.

Parameter	Value	Notes
CTE — X-axis	14 ppm/°C	In-plane thermal expansion
CTE — Y-axis	14 ppm/°C	In-plane thermal expansion
CTE — Z-axis	24 ppm/°C	Through-hole reliability concern
Thermal Conductivity	0.42 W/m·K	Moderate — not a thermal management substrate
Glass Transition Temperature (Tg)	> 260°C	PTFE-based, no traditional Tg
Decomposition Temperature (Td)	> 500°C	PTFE thermal stability
Operating Temperature Range	-55°C to +260°C	Continuous service
Flexural Strength	10,000 psi
Tensile Strength	6,000 psi
Specific Gravity	2.22 g/cm³	Denser than FR-4 (~1.85)
Available Thicknesses	5, 10, 15, 20, 30, 60 mil	Standard catalog; custom available
Available Copper Weights	½ oz, 1 oz, 2 oz	ED and RA copper options

The Z-axis CTE of 24 ppm/°C is a notable number for through-hole and via design. PTFE-based laminates expand more in the Z-direction than in the X-Y plane during thermal excursion. For plated through-holes and blind vias in multi-layer AD300 assemblies, this places cyclic stress on the barrel copper. Via aspect ratio guidelines and annular ring sizing need to account for this, especially in designs that see wide temperature swings in service.

The effectively unlimited upper temperature limit (PTFE doesn’t go through a glass transition the way epoxy laminates do) means AD300 survives lead-free reflow without the dimensional instability problems you get with lower-Tg materials. This is a genuine practical advantage — you can run the board through standard SMT assembly without special thermal precautions.

Arlon AD300 vs. Competing High-Frequency Laminates

The competitive landscape for 3.0 Dk PTFE laminates is reasonably well-defined. Here’s how AD300 positions against the most commonly specified alternatives:

Material	Manufacturer	Dk (10GHz)	Df (10GHz)	Key Differentiator
Arlon AD300	Arlon	3.0	0.0014	Tight Dk tolerance, cost-competitive
Rogers RT/duroid 5880	Rogers	2.2	0.0009	Lower Dk, excellent Df, premium cost
Rogers RO3003	Rogers	3.0	0.0010	Similar Dk, better Df, higher cost
Rogers RO4003C	Rogers	3.55	0.0027	Hydrocarbon ceramic, FR-4 process compatible
Taconic TLY-5	Taconic	2.17	0.0009	Very low Dk, direct duroid alternative
Isola I-Tera MT40	Isola	3.45	0.0031	Modified epoxy, cost-effective for lower GHz
Nelco N4000-13 SI	Nelco	3.7	0.0085	High-speed digital focus, not RF-optimized

The honest comparison: Rogers RO3003 edges out AD300 on dissipation factor (0.0010 vs. 0.0014) with the same nominal Dk. Whether that difference matters depends entirely on your application. For a 2–6 GHz filter or low-noise amplifier, the practical performance gap between the two materials is small enough that fabrication consistency and supply chain factors often tip the decision. For a 77 GHz automotive radar front-end or a millimeter-wave imaging system, the lower-loss Rogers material may be worth the cost premium.

AD300’s cost advantage over Rogers materials is real and consistent in volume production. For commercial applications where the Df specification is met by both materials, AD300 is frequently the economically rational choice.

PCB Design Considerations for Arlon AD300

H3: Transmission Line Impedance Design on AD300

With a Dk of 3.0, AD300 yields transmission line geometries that are practical to fabricate. For 50Ω microstrip on 20 mil (0.508mm) substrate with 1 oz copper, the trace width works out to approximately 45–47 mil (1.14–1.19mm) depending on the specific copper thickness and etching profile. Most RF fabricators are comfortable holding ±5% impedance tolerance on these geometries, and tighter tolerances are achievable with laser direct imaging and controlled-impedance fabrication processes.

For stripline designs in multilayer AD300 stackups, the symmetric configuration with AD300 core and prepreg should use matched Dk materials throughout. Mixing AD300 with standard FR-4 prepreg in a hybrid stack creates Dk discontinuities that complicate impedance calculations and introduce predictable but annoying correction factors into the design flow.

H3: Managing PTFE-Specific Fabrication Challenges

PTFE laminates require different handling than FR-4 in several stages of PCB fabrication, and these process requirements directly affect your design rules and vendor selection.

Hole drilling: PTFE is softer than FR-4 and has a tendency to smear under drill heat. Most qualified PTFE fabricators use slower drill speeds, smaller peck depths, and specialized drill geometries to avoid tearing the material around via barrels. Minimum drillable hole sizes are slightly larger than FR-4 norms — plan for a 0.25mm minimum mechanical drill with 0.1mm annular ring minimum as a starting point, and confirm with your specific fabricator.

Surface preparation for adhesion: PTFE is chemically inert, which is why it’s good for low-loss RF applications and terrible for bonding. Before applying soldermask or laminating in a multilayer process, the surface must be treated — typically with sodium naphthalene etching or plasma activation — to make it bondable. This is a standard process step at qualified PTFE PCB shops, but it’s a process step that’s simply absent at shops that only handle FR-4. Qualifying your fabricator for PTFE processing before committing to AD300 in a design is not optional.

Thermal relief for through-hole pads: PTFE’s low thermal conductivity means heat dissipates more slowly through the laminate during soldering. Adjust thermal relief spoke widths accordingly, or you’ll get cold solder joints on through-hole components on boards that solder perfectly at the same profile on FR-4.

H3: Copper Foil Selection for AD300 Designs

AD300 is available with both electrodeposited (ED) and rolled-annealed (RA) copper foils. The choice matters at higher frequencies.

Copper Type	Surface Roughness	Best For
Electrodeposited (ED)	Higher roughness	Cost-sensitive, <10 GHz
Rolled Annealed (RA)	Smoother surface	>10 GHz, insertion loss critical
Very Low Profile (VLP) ED	Intermediate	Mid-range performance/cost

At millimeter-wave frequencies, copper surface roughness becomes a meaningful contributor to conductor loss through the skin effect. The current at high frequency flows in a thin surface layer, and a rough copper-laminate interface increases the effective path length of that current. For designs above 20 GHz, specifying RA or VLP copper on AD300 is worth the incremental cost.

H3: Stackup Planning for Multilayer AD300 Designs

Multilayer PTFE boards require specialized prepreg — standard woven glass/epoxy prepregs are not compatible with PTFE core laminates for RF performance or bonding chemistry. Arlon’s AP6000 or AP8000 adhesive films, or PTFE-based bonding sheets, are the appropriate choice. The Dk of the bonding film must be factored into any buried or embedded stripline impedance calculation.

A common practical stackup for a 4-layer AD300 RF board:

• Layer 1: Signal (microstrip)
• Layer 2: Ground plane
• Layer 3: Power / secondary signal
• Layer 4: Signal (microstrip or ground)

The core between layers 1-2 and 3-4 uses AD300 at the specified thickness for impedance control. The bond between layers 2-3 uses PTFE bonding film, with its Dk accounted for in the stack-up calculation.

H3: Grounding and Via Design Best Practices

Via stitching around RF transmission lines and beneath ground planes is more important on PTFE substrates than on FR-4 because the lower Dk supports faster wave propagation, making the same physical via pitch represent a larger fraction of a wavelength. Ground via fences should be placed at no more than λ/10 spacing at the highest operating frequency to suppress parallel plate mode propagation between copper planes.

For the Z-axis CTE mismatch noted earlier, via aspect ratios should be kept below 10:1 for through-holes in thermally stressed applications, and back-drilled stubs in high-speed designs should be specified with the PTFE expansion behavior factored into the stub length tolerance.

Applications Where Arlon AD300 Is Cmmonly Specified

Application	Why AD300 Is Suitable
Phased array antenna elements	Stable Dk ensures uniform beam pointing; PTFE handles thermal cycling
Radar front-end PCBs (S, C, X band)	Low Df minimizes insertion loss in T/R modules
Satellite communication hardware	Temperature stability over wide range; radiation-tolerant PTFE matrix
Military EW / SIGINT modules	MIL-spec process compatibility; well-documented qualification data
Base station power amplifier boards	Low loss at cellular frequencies; handles PA thermal environment
Microwave bandpass filters	Tight Dk tolerance required for resonator dimensions
Medical imaging RF boards (MRI coils)	Low loss, non-magnetic, stable in magnetic environments
Test and measurement fixtures	Consistent dielectric for calibration-grade hardware

Arlon AD300 Availability and Ordering Information

AD300 is a catalog material available through Arlon’s authorized distribution network and directly from Arlon Electronic Materials. Standard panel sizes are 12×18 inches and 18×24 inches. Custom panel sizes are available for volume production programs with appropriate lead times.

When specifying AD300 for a project, the part number structure includes substrate thickness, copper weight, and copper type. Confirm availability of specific thickness/copper combinations with your distributor before locking in the stack-up, as not all combinations are stocked at every distribution point.

Useful Resources for Arlon AD300 Design

• Arlon AD300 Official Datasheet — arlon-med.com — Full electrical, mechanical, and thermal specifications with test conditions
• Arlon PCB Material Selection Guide — arlon-med.com — Cross-reference across the full AD, CuClad, and CLTE series
• IPC-4103 Specification for High-Frequency Base Materials — Industry standard governing dielectric constant and loss tangent testing methods for RF laminates
• Rogers MWI-2000 Microwave Impedance Calculator — rogerscorp.com — Free web-based impedance calculator; input AD300’s Dk=3.0 for accurate trace width calculations
• Keysight ADS Substrate Editor — Compatible with AD300 parameters for full-wave and planar EM simulation
• Sonnet Lite — Free EM simulation tool suitable for initial transmission line and filter design on AD300
• Digi-Key / IHS Markit Part Search — Distributor-level availability and pricing for AD300 in standard thicknesses
• JEDEC Standards for High-Frequency Laminate Qualification — Reference for defense and aerospace qualification requirements applicable to AD300

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FAQs About Arlon AD300

Q1: How does Arlon AD300 compare to Rogers RO3003 for microwave PCB design? Both materials share a nominal Dk of 3.0, but Rogers RO3003 has a slightly better dissipation factor (0.0010 vs. AD300’s 0.0014 at 10 GHz). For most applications below 20 GHz, the insertion loss difference is small enough that it doesn’t determine design success. AD300 typically offers a cost advantage in volume production. For millimeter-wave applications or designs where every tenth of a dB of insertion loss matters, RO3003 has the edge. The fabrication processes for both materials are essentially identical, so switching between them rarely requires re-qualifying your PCB shop.

Q2: Can Arlon AD300 be processed in a standard FR-4 PCB fabrication line? Not without PTFE-specific process steps. PTFE laminates require surface activation treatment before multilayer lamination and soldermask application, specialized drilling parameters to avoid material smear, and compatible prepreg or bonding films for multilayer constructions. A shop that processes only FR-4 cannot run AD300 without process additions. Always verify PTFE processing capability with your fabricator before specifying AD300 in a design.

Q3: What is the maximum frequency at which Arlon AD300 performs reliably? Arlon publishes Dk and Df data to 10 GHz. The material is used in production hardware through X-band (8–12 GHz) routinely and into Ku-band (12–18 GHz) in many designs. There is application experience with AD300 into Ka-band (26–40 GHz), though at millimeter-wave frequencies, copper surface roughness and fabrication tolerances become increasingly important alongside the material properties. For designs above 30 GHz, careful simulation and prototype measurement should be used to validate actual insertion loss rather than relying solely on bulk material Df.

Q4: Is Arlon AD300 suitable for lead-free assembly processes? Yes. PTFE-based laminates like AD300 have no glass transition temperature in the conventional sense and withstand temperatures well above the 260°C peak reflow temperatures used in lead-free assembly. Unlike some hydrocarbon-ceramic laminates that require special assembly profiling, AD300 processes through standard lead-free SMT reflow without dimensional issues. The primary assembly consideration is thermal relief design on through-hole pads, where AD300’s lower thermal conductivity compared to FR-4 can require minor profile adjustments to achieve reliable through-hole solder fillets.

Q5: Where can I get Arlon AD300 fabricated into finished PCBs? AD300 fabrication requires a PCB manufacturer qualified for PTFE/microwave laminates. Major RF PCB specialists including API Technologies, TTM Technologies, Candor Industries, and Würth Elektronik’s RF division handle AD300 routinely. In Asia, several Taiwanese and Chinese RF PCB specialists are qualified for PTFE processing. When requesting quotes, explicitly specify “PTFE-qualified fabrication” and ask for the shop’s process documentation for sodium naphthalene or plasma treatment, as this confirms genuine PTFE capability versus shops that claim PTFE experience without the necessary process controls.

Final Assessment: Is Arlon AD300 the Right Choice for Your Design?

Arlon AD300 hits a practical sweet spot for RF and microwave PCB designs that need reliable low-loss performance without the full cost burden of premium Rogers materials. The tight Dk tolerance of ±0.04 supports accurate impedance and filter designs. The Df of 0.0014 is competitive for most applications through X-band. The PTFE matrix provides temperature stability that outlasts the product’s useful life in the overwhelming majority of deployment environments.

The material demands a qualified fabricator and careful attention to the PTFE-specific design rules around via sizing, bonding films, and copper roughness specification. None of those challenges are exotic — any RF PCB shop worth working with handles them routinely. For engineers evaluating AD300 against Rogers RO3003 or competing ceramic PTFE laminates, the decision usually comes down to Df specification headroom and unit cost at volume. For engineers comparing AD300 to FR-4, the conversation ends at the first GHz — there’s simply no comparison.

Arlon AD255C PCB material: full technical breakdown covering dielectric constant (Dk 2.55), loss tangent (Df 0.0019), mechanical properties, datasheet specs, fabrication tips, and real-world applications in radar, 5G, and satellite systems. Written for RF and microwave PCB engineers.

If you’ve been specifying PCB materials for RF and microwave designs long enough, you know that choosing the wrong substrate can quietly kill your system’s performance — and no amount of tuning fixes a lossy board. The Arlon AD255C sits in that sweet spot where engineers need a low-loss, dimensionally stable PTFE-based laminate that actually behaves consistently across production runs. This article digs into what makes the AD255C tick, its full property profile, how it stacks up against competing materials, and where it genuinely belongs in your design.

What Is Arlon AD255C?

The Arlon AD255C is a PTFE (polytetrafluoroethylene) woven-glass composite laminate engineered specifically for high-frequency, microwave, and RF PCB applications. It belongs to Arlon’s AD Series of microwave laminates — a product line originally developed by Arlon EMC (Electronic Materials and Components), now marketed under the Rogers Corporation Advanced Electronics Solutions umbrella following Rogers’ acquisition of Arlon in 2019.

The “255” in the name directly signals its defining characteristic: a nominal dielectric constant of 2.55. That low Dk, combined with its ceramic-loaded PTFE matrix, makes this material a go-to choice when designers need predictable signal propagation, tight impedance control, and minimal insertion loss from L-band through millimeter-wave frequencies.

Unlike pure PTFE substrates (such as RT/duroid® 5880), the AD255C incorporates woven glass reinforcement and ceramic filler particles, which dramatically improves its dimensional stability and x/y-axis CTE (Coefficient of Thermal Expansion) compared to unfilled PTFE. This makes it significantly more manufacturable while preserving the RF performance benefits of a low-Dk substrate.

Arlon AD255C Key Electrical Properties

The electrical performance of any high-frequency laminate is defined primarily by its dielectric constant and loss tangent. Everything else flows downstream from these two numbers.

Electrical Property	Value	Test Method
Dielectric Constant (Dk)	2.55 ± 0.04	IPC-TM-650 2.5.5.5 @ 10 GHz
Loss Tangent (Df)	0.0019	IPC-TM-650 2.5.5.5 @ 10 GHz
Volume Resistivity	>10⁹ MΩ·cm	IPC-TM-650 2.5.17.1
Surface Resistivity	>10⁷ MΩ	IPC-TM-650 2.5.17.1
Dielectric Breakdown Voltage	>1,000 V/mil	ASTM D149
Relative Permittivity Stability vs. Frequency	Excellent (flat to >77 GHz)	—

A loss tangent of 0.0019 is genuinely low. For reference, standard FR-4 runs at 0.020–0.025 at 1 GHz — roughly 10 to 13 times higher. Even against mid-tier RF materials like Rogers RO4003C (Df = 0.0027 at 10 GHz), the AD255C offers measurably lower insertion loss per unit length. When you’re routing a 10 cm transmission line at 24 GHz in an automotive radar front-end, that difference adds up fast.

The tight Dk tolerance of ±0.04 is worth calling out separately. Consistent dielectric constant across a panel — and across production lots — is what allows you to design a 50-ohm microstrip once and actually get it at the fab house. Materials with loose Dk tolerances push variability onto impedance, and that becomes a manufacturing yield problem.

Arlon AD255C Mechanical and Thermal Properties

PTFE-based materials have historically suffered from poor dimensional stability and a reputation for being difficult to fabricate. The ceramic-loaded woven glass construction of the AD255C addresses this without sacrificing RF performance.

Mechanical/Thermal Property	Value	Test Method
CTE — X-axis	17 ppm/°C	IPC-TM-650 2.4.41
CTE — Y-axis	17 ppm/°C	IPC-TM-650 2.4.41
CTE — Z-axis	24 ppm/°C	IPC-TM-650 2.4.41
Thermal Conductivity	0.20 W/m·K	ASTM C518
Glass Transition Temperature (Tg)	>260°C (PTFE matrix)	—
Decomposition Temperature (Td)	>260°C	—
Moisture Absorption	<0.10%	IPC-TM-650 2.6.2
Density	~2.14 g/cm³	—
Tensile Strength (X/Y)	~103 MPa	IPC-TM-650 2.4.18
Copper Peel Strength (1 oz Cu)	>5 lb/inch	IPC-TM-650 2.4.8
Flammability Rating	UL 94 V-0	UL 94

The z-axis CTE of 24 ppm/°C is well within the range that allows reliable through-hole and via integrity over thermal cycling. This is a significant improvement over unfilled PTFE, which can exhibit z-axis CTE values exceeding 150 ppm/°C — a number that catastrophically stresses barrel plating during thermal excursions.

The moisture absorption below 0.10% means the material’s Dk remains stable in humid field environments, which matters enormously for outdoor telecoms equipment and airborne radar systems where humidity cycling is unavoidable.

Available Configurations: Thickness and Copper Options

Arlon AD255C is available in a range of standard panel sizes and configurations to suit multilayer and single/double-sided designs.

Parameter	Available Options
Dielectric Thickness	5 mil (0.127 mm), 10 mil (0.254 mm), 20 mil (0.508 mm), 30 mil (0.762 mm), 60 mil (1.524 mm), 125 mil (3.175 mm)
Copper Weight	½ oz/ft² (17 µm), 1 oz/ft² (35 µm), 2 oz/ft² (70 µm)
Copper Type	Electrodeposited (ED) and Rolled Annealed (RA)
Panel Size	Standard 18″ × 24″ panels; custom available
Reinforcement	Woven PTFE/ceramic composite

For most microstrip and stripline designs operating above 10 GHz, the 10 mil (0.254 mm) and 20 mil (0.508 mm) dielectric thicknesses are the most commonly specified. Thinner substrates minimize surface wave excitation and produce tighter-tolerance line widths for high-impedance structures.

Rolled annealed (RA) copper is preferred for flex-related assemblies and for applications where surface roughness at the copper-dielectric interface is a concern. At millimeter-wave frequencies, copper surface roughness increases insertion loss due to the skin effect, so RA copper’s smoother profile translates to measurable performance improvement above 30 GHz.

How Arlon AD255C Compares to Other High-Frequency PCB Materials

No PCB engineer should select a laminate in isolation. Here is how the AD255C sits within the broader landscape of commonly specified high-frequency substrates.

Material	Dk @ 10 GHz	Df @ 10 GHz	CTE Z (ppm/°C)	Notes
Arlon AD255C	2.55	0.0019	24	PTFE/ceramic woven glass
Rogers RT/duroid® 5880	2.20	0.0009	46	Unreinforced PTFE/glass microfiber
Rogers RO4003C	3.55	0.0027	46	Hydrocarbon/ceramic
Rogers RO4350B	3.48	0.0037	32	Hydrocarbon/ceramic
Taconic RF-35	3.50	0.0018	40	PTFE/ceramic
Isola I-Tera MT40	3.45	0.0031	41	Modified epoxy
FR-4 (standard)	4.3–4.8	0.020–0.025	70	Epoxy/woven glass

Several things stand out from this comparison. The AD255C has a lower Dk than RO4003C, which means signal propagation is faster and line widths are narrower for the same impedance — useful when minimizing circuit size matters. Its loss tangent of 0.0019 beats RO4350B (0.0037) and RO4003C (0.0027) comfortably, placing it closer to duroid 5880 territory in terms of insertion loss.

The trade-off compared to RT/duroid 5880 is that AD255C has a slightly higher Dk (2.55 vs. 2.20) and moderately higher Df (0.0019 vs. 0.0009). However, the AD255C’s reinforced construction gives it far better mechanical stability, easier fabrication, and superior dimensional repeatability — which often makes it the more practical choice in production environments where duroid 5880’s notoriously difficult handling would hurt yield.

Arlon AD255C PCB Fabrication Guidelines

Working with PTFE-based laminates requires process adjustments that FR-4 shops may not be set up for. Understanding these ahead of time prevents expensive surprises.

Through-Hole and Via Preparation

PTFE is chemically inert, meaning standard permanganate or alkaline desmear processes used for epoxy laminates will not adequately prepare the hole walls for copper electroless plating. You must use one of the following activation methods before electroless copper deposition:

Sodium naphthalene (sodium etch): The traditional and most effective method for PTFE. Chemically etches the fluoropolymer surface to create adhesion sites for electroless copper.

Plasma treatment: An increasingly common alternative, plasma etching (oxygen/nitrogen or CF₄-based) activates the PTFE surface without hazardous chemical byproducts. It is generally preferred in modern environmentally compliant shops.

Skipping or inadequately performing this step results in poor barrel adhesion, which manifests as via failures during thermal cycling — the kind of intermittent defect that takes weeks to root-cause in the field.

Drilling

Use sharp carbide drill bits with appropriate chip load and speeds for PTFE composites. PTFE’s low modulus and tendency to smear at elevated temperatures demands conservative feed rates. Dull tooling causes fiber pullout and hole wall roughness that compromises plating adhesion. Diamond-coated tooling extends bit life significantly in production runs.

Copper Etching

Standard ferric chloride and ammonium persulfate etchants work well with AD255C. The relatively smooth dielectric surface means fine line geometries are achievable. At sub-mil line widths above 60 GHz, work closely with your fabricator on etch factor compensation, as undercut becomes a meaningful variable.

Soldering and Assembly

The AD255C’s PTFE matrix means it can withstand standard lead-free reflow profiles (peak temperatures around 260°C) without laminate damage, though care should be taken with thermal excursions for assemblies under mechanical stress. The UL 94 V-0 flame rating means it satisfies most commercial and military flammability requirements.

For complete guidance on working with Arlon PCB materials in production, fabricators with specific PTFE handling experience will yield significantly better results than standard epoxy laminates shops.

Primary Applications of Arlon AD255C

The combination of low Dk, very low loss tangent, and excellent thermal stability positions the AD255C in demanding RF and microwave applications where substrate performance is a first-order design constraint.

Phased Array Antenna Systems

Phased arrays — whether for 5G mmWave base stations, electronic warfare systems, or satellite communications — require large-format, low-loss substrates with extremely consistent Dk across the panel. Any Dk variation translates directly to phase error between array elements, degrading beam steering accuracy and sidelobe performance. The AD255C’s tight ±0.04 Dk tolerance and woven glass reinforcement make it well-suited for radiating layer substrates in these systems.

Automotive Radar (77 GHz / 79 GHz)

Modern ADAS radar modules operating at 77–79 GHz push the limits of even premium laminates. At these frequencies, even small increases in loss tangent cause significant insertion loss over centimeter-scale transmission lines. The AD255C’s low Df and relatively flat Dk vs. frequency characteristic out to millimeter-wave frequencies make it a credible choice for front-end patch antenna arrays in automotive radar front-ends.

Satellite Ground Station Equipment

Low-noise block downconverters (LNBs), feed networks, and power dividers in satellite receive systems benefit from the AD255C’s combination of low loss and stable environmental performance. Outdoor equipment exposed to humidity cycles and temperature extremes demands a substrate with moisture absorption below 0.1% — a spec the AD255C meets comfortably.

Military and Defense Electronics

From airborne electronic countermeasure (ECM) pods to shipboard radar front-ends, defense electronics require materials that maintain specification across extreme temperature ranges and pass vibration/shock testing. The AD255C’s ceramic-reinforced PTFE construction handles mechanical stress better than unfilled alternatives and satisfies MIL-spec material traceability requirements when sourced through qualified distributors.

Base Station Filters and Couplers

RF power dividers, hybrid couplers, and bandpass filters in cellular base station hardware have demanding insertion loss budgets. The AD255C’s Df of 0.0019 helps keep filter Q factors high and insertion loss low across the 3.5 GHz, 28 GHz, and 39 GHz bands being deployed in 5G infrastructure.

Microwave Backhaul Links

Point-to-point microwave backhaul links operating at E-band (71–86 GHz) and V-band (57–64 GHz) require the lowest practical dielectric loss to hit link budget targets over kilometer-scale paths. The AD255C is suitable for the RF front-end PCB assemblies in these systems, particularly for antenna feeding networks and local oscillator distribution circuits.

Useful Resources and Official Datasheet Access

The following resources are directly useful when specifying or evaluating Arlon AD255C for a design:

Resource	Description	Link
Rogers Corporation — AD Series Laminates	Official product family page (post-Arlon acquisition)	rogerscorp.com
Arlon AD255C Official Datasheet (PDF)	Full material property tables, dimensional data, and test methods	Available via Rogers Corp Document Library
IPC-4103 Specification	Industry standard covering high-frequency/high-speed laminates including PTFE-based materials	ipc.org
IPC-TM-650 Test Methods	Standardized test procedures referenced in the AD255C datasheet	ipc.org/test-methods
Rogers Design Support Hub	Microstrip/stripline impedance calculators and material selection tools	rogerscorp.com
MIL-P-13949 (Military Specification)	Applicable military laminate specification relevant to defense procurement	Available via ASSIST QuickSearch (quicksearch.dla.mil)

When downloading the official datasheet, verify that you are reviewing the current revision. Properties may be updated by the manufacturer, and older cached versions circulating online occasionally contain superseded values — particularly loss tangent figures that have been refined as measurement methods improved.

Frequently Asked Questions About Arlon AD255C

Q1: What is the dielectric constant of Arlon AD255C, and how stable is it with frequency?

The nominal dielectric constant of AD255C is 2.55 ± 0.04 measured at 10 GHz using IPC-TM-650 2.5.5.5. One of the genuine strengths of PTFE-based materials over hydrocarbon/ceramic laminates is that their Dk vs. frequency curve is very flat. The AD255C maintains a consistent Dk from around 1 GHz through 77 GHz and beyond, making it reliable for designs that need predictable line impedances across wide frequency spans.

Q2: Can Arlon AD255C be processed in a standard FR-4 PCB shop?

Not without modifications. The primary process change is in through-hole preparation: PTFE requires sodium naphthalene etching or plasma treatment before electroless copper plating. Shops without this capability will produce poor via reliability. Additionally, drill parameters need adjustment for PTFE’s different mechanical properties. Shops experienced in PTFE laminates (Rogers, Taconic, Arlon materials) should be specified on the fabrication drawing.

Q3: How does Arlon AD255C compare to Rogers RT/duroid 5880?

RT/duroid 5880 has a lower Dk (2.20) and lower Df (0.0009), making it superior in pure RF performance. However, duroid 5880 uses an unreinforced construction that results in poor dimensional stability, very high z-axis CTE (~46 ppm/°C vs. AD255C’s 24 ppm/°C), and difficult handling in production. For designs where cost, yield, and fabrication reliability are as important as maximum RF performance, many engineers prefer the AD255C. At frequencies below 40 GHz, the performance difference is often acceptable.

Q4: What frequency range is Arlon AD255C suitable for?

The AD255C performs well across an extremely wide frequency range. It is a credible substrate choice from VHF/UHF (sub-1 GHz) all the way through E-band (71–86 GHz) and potentially beyond at reduced substrate thickness. The flat Dk vs. frequency characteristic and low loss tangent allow it to be used in broadband designs without significant derating compared to narrowband applications.

Q5: Is Arlon AD255C RoHS compliant and suitable for lead-free assembly?

Yes. The AD255C is RoHS compliant. Its PTFE matrix, which has a decomposition temperature above 260°C, handles lead-free reflow profiles without laminate damage. The UL 94 V-0 flammability rating is maintained after assembly. For high-temperature lead-free solder processes, verify specific assembly conditions with your material supplier or fabricator, particularly for thick-format boards where thermal gradients during reflow can stress the laminate more severely.

Final Thoughts: When to Choose Arlon AD255C

As a PCB material engineer, the decision to specify the AD255C almost always comes down to needing sub-3 Dk, sub-0.002 Df, and production-viable PTFE processing in a single laminate. It threads a needle that pure PTFE (like duroid 5880) misses on manufacturability, and that hydrocarbon-ceramic laminates (like RO4003C) miss on raw electrical performance.

It’s the kind of material choice that becomes obvious once you’ve spent enough time troubleshooting yield issues on a duroid-based assembly line, or chasing the last 0.3 dB of insertion loss margin in a 77 GHz radar feed network. If your application lives in that space — phased array antennas, automotive radar, satellite communications, defense RF front-ends — the Arlon AD255C deserves serious consideration in your material selection process.

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Arlon AD255C PCB material: full technical breakdown covering dielectric constant (Dk 2.55), loss tangent (Df 0.0019), mechanical properties, datasheet specs, fabrication tips, and real-world applications in radar, 5G, and satellite systems. Written for RF and microwave PCB engineers.

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Arlon AD255C PCB laminate: Dk 2.55, Df 0.0019, full datasheet specs, fabrication guidelines, and applications in radar, 5G mmWave, satellite, and defense electronics.