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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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Arlon CLTE vs CLTE-MW vs CLTE-P: specs, Z-CTE differences, via reliability, and application guidance for RF, radar, and mmWave PCB engineers. Full comparison inside.