Arlon DiClad 880: Ultra-Low Dk PTFE PCB Laminate for High-Speed RF Design

When a design truly cannot afford any more insertion loss, when faster signal propagation speed is a hard requirement rather than a wish-list item, and when the application absolutely demands the lowest dielectric constant available in a fiberglass-reinforced PTFE laminate — that’s exactly where Arlon DiClad 880 belongs. It represents the far end of the DiClad product spectrum: a low fiberglass/PTFE ratio construction that delivers the lowest Dk (2.17 or 2.20) and dissipation factor (0.0009 at 10 GHz) in the entire DiClad family. No other woven fiberglass-reinforced PTFE laminate from the Arlon line pushes these numbers further. This guide is a complete engineering review — every published spec, every thickness and copper option, where it fits and where it doesn’t, how it stacks up against the competition, and what your fabricator needs to know before the first panel goes through the drill.

What Is Arlon DiClad 880?

Arlon DiClad 880 is a woven fiberglass-reinforced PTFE composite laminate manufactured for use as a printed circuit board substrate in microwave and RF applications. It is the lowest-Dk, lowest-loss product in the DiClad series — the family of PTFE-based PCB laminates that Arlon EMD has produced for decades and which continues in production under Elite Material Co. (EMC) ownership following the January 2021 acquisition, with no changes to specifications or manufacturing at the Rancho Cucamonga, California facility.

The design philosophy behind DiClad 880 is explicit in the Arlon datasheet: it uses a low fiberglass/PTFE ratio to provide the lowest dielectric constant and dissipation factor available in fiberglass-reinforced PTFE-based laminates. Together, these properties offer faster signal propagation and higher signal-to-noise ratios — exactly the trade Arlon intended. The consequence of reducing fiberglass content this far is that the material becomes noticeably softer and less dimensionally stable than the more heavily reinforced DiClad 522/527 or DiClad 870. That trade-off is real and needs to be factored into both design and fabrication decisions.

Understanding DiClad 880 in the context of the full DiClad product family is essential. The line runs from DiClad 522/527 (high fiberglass content, Dk 2.40–2.65, best mechanical properties) through DiClad 870 (medium content, Dk 2.33) down to DiClad 880 (low fiberglass content, Dk 2.17–2.20, best electrical properties). Each step down the fiberglass-content ladder trades mechanical performance for electrical performance. DiClad 880 is the endpoint of that progression.

Arlon DiClad 880 Full Electrical Specifications

All values below are from the official Arlon/RS-online published datasheet, tested on 0.062″ dielectric thickness exclusive of metal cladding. These are the numbers to use in your field solver, stack-up models, and simulation software.

Parameter	Test Method	Condition	DiClad 880
Dielectric Constant (Dk) @ 10 GHz	IPC TM-650 2.5.5.5	C23/50	2.17 or 2.20
Dielectric Constant (Dk) @ 1 MHz	IPC TM-650 2.5.5.3	C23/50	2.17 or 2.20
Dissipation Factor (Df) @ 10 GHz	IPC TM-650 2.5.5.5	C23/50	0.0009
Dissipation Factor (Df) @ 1 MHz	IPC TM-650 2.5.5.3	C23/50	0.0008
Thermal Coefficient of Er (ppm/°C)	IPC TM-650 2.5.5.5 Adapted	–10°C to +140°C	–160
Volume Resistivity (MΩ-cm)	IPC TM-650 2.5.17.1	C96/35/90	1.4 × 10⁹
Surface Resistivity (MΩ)	IPC TM-650 2.5.17.1	C96/35/90	2.9 × 10⁶
Arc Resistance (seconds)	ASTM D-495	D48/50	> 180
Dielectric Breakdown (kV)	ASTM D-149	D48/50	> 45
Water Absorption (%)	MIL-S-13949H / IPC TM-650 2.6.2.2	E1/105 + D24/23	0.02
Flammability	UL File E 80166	UL94 Vertical Burn	UL94V-0

Several numbers here are worth lingering on. The Df of 0.0009 at 10 GHz is the headline figure — this is the lowest dissipation factor in the fiberglass-reinforced PTFE category. For context, standard FR-4 runs a Df around 0.020 or higher at 10 GHz; that’s more than twenty times worse. Even DiClad 522/527 (Df 0.0022 at 10 GHz) is 2.4× higher than DiClad 880. Every 0.001 reduction in dissipation factor produces a measurable reduction in dielectric insertion loss, and at 0.0009, DiClad 880 is as close to lossless as you’ll get with a fiberglass-reinforced substrate.

The Dk options of 2.17 and 2.20 are equally important. A Dk of 2.17 is within striking distance of pure PTFE (Dk ≈ 2.1), meaning the fiberglass content is contributing only marginally to the dielectric. Signal propagation velocity in a DiClad 880 microstrip or stripline is very close to the speed obtainable in unloaded PTFE — significantly faster than DiClad 522 or DiClad 870, and faster still compared to RO4350B (Dk 3.48). For delay-sensitive designs in radar processors, high-data-rate backplanes with controlled propagation timing, or phased array systems where phase precision is everything, the lower Dk translates directly into shorter time-of-flight and tighter phase matching.

The Dk is also completely flat from 1 MHz to 10 GHz — no dispersion correction needed across this range. That’s a property of PTFE-based materials that thermoset laminates simply cannot match.

Arlon DiClad 880 Full Mechanical and Physical Properties

The mechanical data tells the full story of DiClad 880’s trade-off: outstanding electrical properties paired with reduced mechanical rigidity compared to the rest of the DiClad family.

Parameter	Test Method	Condition	DiClad 880
CTE — X Axis (ppm/°C)	IPC TM-650 2.4.24 / Mettler TMA	0°C to 100°C	25
CTE — Y Axis (ppm/°C)	IPC TM-650 2.4.24 / Mettler TMA	0°C to 100°C	34
CTE — Z Axis (ppm/°C)	IPC TM-650 2.4.24 / Mettler TMA	0°C to 100°C	252
Tensile Modulus — X/Y (kpsi)	ASTM D-638	A, 23°C	267 / 202
Tensile Strength — X/Y (kpsi)	ASTM D-882	A, 23°C	8.1 / 7.5
Compressive Modulus (kpsi)	ASTM D-695	A, 23°C	237
Flexural Modulus (kpsi)	ASTM D-790	A, 23°C	357
Specific Gravity (g/cm³)	ASTM D-792 Method A	A, 23°C	2.23
Thermal Conductivity (W/mK)	ASTM E-1225	100°C	0.261
Typical Peel Strength (lbs/in)	IPC TM-650 2.4.8	35 µm foil	~14

The tensile modulus of 267 kpsi (X-axis) versus DiClad 522’s 706 kpsi tells the story plainly: DiClad 880 is roughly 38% as stiff as the highly reinforced DiClad 522/527. This isn’t a subtle difference — it means DiClad 880 panels flex more during handling, are more susceptible to scratching and surface damage, and require more care during drilling and routing. Fabrication teams that have only worked with DiClad 522 will notice the difference immediately.

The Z-axis CTE of 252 ppm/°C is the highest in the DiClad family (DiClad 870: 217, DiClad 522/527: 173) and is a serious consideration for multilayer constructions with through-hole plating. Higher Z-axis expansion under thermal cycling puts more stress on plated via barrels, accelerating fatigue failures. For thick multilayer DiClad 880 boards or any design with high-aspect-ratio vias that will see significant thermal cycling, copper plating thickness and via design should be reviewed against IPC-6012 Class 3 requirements.

DiClad 880 NASA Outgassing Data

Parameter	DiClad 880 Result	NASA Pass Limit
Total Mass Loss (TML)	0.01%	< 1.00%
Collected Volatile Condensable Material (CVCM)	0.01%	< 0.10%
Water Vapor Regain	0.01%	—
Visible Condensate	None	None

DiClad 880 clears NASA ASTM E595 outgassing requirements with the same comfortable margin as the rest of the DiClad family. The extremely low outgassing values reflect PTFE’s inherently inert chemistry — PTFE does not decompose or off-gas under the vacuum and elevated temperature conditions of the NASA test.

The Low Fiberglass/PTFE Ratio: What It Means in Practice

The defining material choice in Arlon DiClad 880 is the deliberate reduction of fiberglass content to near-minimum levels. To understand why this matters, consider what fiberglass does when it’s incorporated into a PTFE laminate:

Fiberglass has a dielectric constant of approximately 6.0–7.0. PTFE has a dielectric constant of approximately 2.1. When you mix the two in a composite, the resulting Dk is a function of volume fractions. More fiberglass pulls Dk up toward 2.6+ (DiClad 522). Less fiberglass keeps Dk close to 2.1 (DiClad 880 at 2.17). The same logic applies to dissipation factor: fiberglass has a higher loss tangent than PTFE, so less fiberglass means lower Df.

The catch is mechanical. Fiberglass is what gives the laminate most of its stiffness, CTE control, and dimensional stability. Reducing it makes the composite softer, increases X-Y-axis CTE, increases Z-axis CTE (worse via reliability), and reduces the tensile and compressive modulus. DiClad 880 at 267 kpsi tensile modulus versus DiClad 522/527 at 706 kpsi is a direct numerical consequence of this trade.

The question designers need to answer honestly is: does your application justify this trade? For designs where the difference between Df 0.0013 (DiClad 870) and Df 0.0009 (DiClad 880) is genuinely system-critical — typically high-data-rate millimeter-wave links, ultra-low-noise receiver front ends, or long phased array feed paths where loss budget is exhausted — the answer is yes. For many microwave applications operating below 20 GHz, DiClad 870 delivers more than enough performance with meaningfully better mechanical properties.

Available Thicknesses and Copper Options for DiClad 880

DiClad 880 is available in master sheet sizes of 36″×48″, 36″×72″, and 48″×54″. It is supplied with copper cladding on both sides as standard, with the following standard configuration options:

Core Thickness (mil / mm)	Standard Copper Weights	Notes
10 mil / 0.254 mm	½ oz (18 µm), 1 oz (35 µm)	Thin core for stripline multilayer
20 mil / 0.508 mm	½ oz (18 µm), 1 oz (35 µm)	Common for 50-ohm microstrip
31 mil / 0.787 mm	½ oz, 1 oz, 2 oz (70 µm)	Standard single-layer work
62 mil / 1.575 mm	1 oz, 2 oz	Thicker core applications

Standard copper foil is electrodeposited (ED). Rolled copper foil is available on request and is strongly recommended for designs above 15–20 GHz where conductor surface roughness becomes a significant contributor to total insertion loss. DiClad 880 is also available bonded to a heavy metal ground plane — aluminum, brass, or copper — providing both a mechanical carrier and an integral heat sink for power-dense applications.

The available Dk values within the DiClad 880 line are 2.17 and 2.20, which reflects slightly different fiberglass/PTFE ratios within the low-content range. The 2.17 version is closer to the PTFE-only limit and will produce slightly wider traces for a given impedance than the 2.20 version. Verify which specific Dk value is available in your target thickness from your material supplier before finalizing stack-up calculations.

Arlon DiClad 880 vs. The Full DiClad Family: Complete Comparison

This is the table most engineers need first — the full side-by-side view of the DiClad product line.

Parameter	DiClad 522/527	DiClad 870	DiClad 880
Fiberglass/PTFE Ratio	High	Medium	Low
Dk @ 10 GHz	2.40 – 2.65	2.33	2.17 / 2.20
Df @ 10 GHz	0.0022	0.0013	0.0009
Df @ 1 MHz	0.0010	0.0009	0.0008
CTE — X Axis (ppm/°C)	14	17	25
CTE — Y Axis (ppm/°C)	21	29	34
CTE — Z Axis (ppm/°C)	173	217	252
Tensile Modulus X (kpsi)	706	485	267
Tensile Strength X (kpsi)	19.0	14.9	8.1
Flexural Modulus (kpsi)	537	437	357
Specific Gravity	2.31	2.26	2.23
Water Absorption (%)	0.03	0.02	0.02
Relative Mechanical Rigidity	Highest	Moderate	Lowest
Relative Fabrication Ease	Easiest (for PTFE)	Moderate	Most demanding

The diagonal progression is unmistakable: as Dk and Df improve moving from DiClad 522/527 → 870 → 880, every mechanical metric moves in the wrong direction. There is no DiClad product that simultaneously achieves Dk 2.17 with the mechanical rigidity of DiClad 522. That material doesn’t exist, and if your application claims to need both, it either doesn’t need the Dk 2.17 as badly as it thinks, or it needs to live with the mechanical trade-off.

Arlon DiClad 880 vs. Rogers RT/duroid 5880: The Critical Comparison

This is the comparison engineers search for most frequently. Both materials have similar electrical targets, similar names, and are genuinely competitive in the same application space.

Parameter	Arlon DiClad 880	Rogers RT/duroid 5880
Glass Reinforcement	Woven fiberglass	Random glass microfibers
Dk @ 10 GHz	2.17 / 2.20	2.20 (± 0.02)
Df @ 10 GHz	0.0009	0.0009
Water Absorption (%)	0.02	0.02
CTE — X Axis (ppm/°C)	25	31
CTE — Y Axis (ppm/°C)	34	48
Dk Uniformity	Good (woven glass)	Excellent (random microfibers)
Dimensional Stability	Moderate	Lower (softer)
Mechanical Rigidity	Slightly higher	Lower
Typical Min Thickness	10 mil	5 mil (0.127 mm)
Availability	Less common	Widely stocked globally

The electrical performance is essentially a draw — both deliver Dk around 2.20 and Df 0.0009 at 10 GHz. The differentiation is structural. RT/duroid 5880 uses randomly oriented glass microfibers, which gives it superior in-plane Dk isotropy and uniformity across frequency — the random distribution avoids the periodic Dk variation associated with woven glass weave. However, that random fiber structure also makes RT/duroid 5880 softer and lower in dimensional stability than DiClad 880’s woven glass construction. DiClad 880’s woven glass gives it a slightly better CTE profile (X: 25 vs 31, Y: 34 vs 48 ppm/°C) and marginally better dimensional stability during fabrication.

For designs where in-plane Dk isotropy is the primary concern — large-format phased arrays, for instance — RT/duroid 5880’s random microfiber structure is an advantage. For designs where dimensional stability during complex multilayer lamination is more important than absolute in-plane isotropy, DiClad 880 holds an edge. In most practical applications, either material works well, and the decision often comes down to stock availability and fabricator familiarity.

Arlon DiClad 880 vs. Taconic TLY-5 and TLY-5A

Taconic TLY-5 and TLY-5A are woven glass PTFE laminates that compete directly with DiClad 880 in the low-Dk woven-glass category.

Parameter	Arlon DiClad 880	Taconic TLY-5	Taconic TLY-5A
Dk @ 10 GHz	2.17 / 2.20	2.20	2.17
Df @ 10 GHz	0.0009	0.0009	0.0009
CTE — Z Axis (ppm/°C)	252	~240	~240
Glass Type	Woven	Woven	Woven
Manufacturer	Arlon/Rogers EMD	Taconic	Taconic

The electrical specs are nearly identical across all three, as you’d expect from materials in the same fiberglass/PTFE ratio range. Material selection between these alternatives frequently comes down to supply chain preference, regional distributor relationships, and which material your fabricator has qualified in their PTFE process documentation. From a pure electrical performance standpoint, a design qualified on DiClad 880 will transfer to TLY-5A with only minor impedance recalculation.

Key Applications for Arlon DiClad 880

DiClad 880’s combination of ultra-low Dk and Df makes it the correct specification for applications where RF performance is non-negotiable and fabrication complexity is manageable.

Millimeter-Wave Circuits and Antennas

At V-band (50–75 GHz) and beyond, dielectric loss becomes a first-order constraint rather than a secondary consideration. Connector runs, transitions, and antenna feed networks that would be low-loss at X-band can consume significant signal at mmWave frequencies if the substrate Df is not as low as possible. DiClad 880’s Df of 0.0009 makes it a natural choice for mmWave antenna elements, passive beamforming networks, and transceiver board layouts in 5G millimeter-wave equipment, automotive 77 GHz radar, and satellite Ka/V-band terminal hardware.

Low-Noise Amplifier (LNA) Input Networks

In sensitive receiver front ends, the impedance match at the LNA input is critical to noise figure. The matching network substrate needs to contribute zero additional noise of its own — which means minimizing dielectric loss in the matching structure. DiClad 880’s lowest-in-class Df makes it the preferred substrate for the most noise-figure-sensitive LNA input boards.

Long Feed Networks in Phased Arrays

A radar or satellite phased array may have hundreds of elements connected by a corporate feed network that routes signal across a large panel. In designs like this, every element in the feed path sees insertion loss from multiple trace segments. A substrate with Df 0.0009 versus 0.0013 or 0.0022 produces a measurable difference in total feed loss — and feed loss directly reduces effective isotropic radiated power (EIRP) and receive sensitivity.

Military Radar and Electronic Warfare

Military radar feed networks and electronic warfare systems are specifically cited as target applications for the DiClad product line. DiClad 880 serves these applications where wide bandwidths, high operating frequencies, and demanding loss budgets require the best available substrate electrical performance.

Power Dividers and Combiners at Microwave Frequencies

Loss in a power combiner heats the termination resistors and reduces the amount of power that reaches the antenna or output port. DiClad 880’s very low Df minimizes this loss term, particularly in designs where the combining network is physically large or operates at high frequencies.

PCB Fabrication Guide for Arlon DiClad 880

DiClad 880 requires all of the same PTFE-specific fabrication steps as DiClad 522/527 and DiClad 870 — but with heightened attention to material handling, because the lower stiffness of DiClad 880 makes it more vulnerable to mechanical damage and dimensional shift at each step.

Handling and Panel Management

DiClad 880’s reduced tensile modulus (267 kpsi) means panels flex and can be easily scratched or deformed during handling. Panels should be handled with clean gloves, supported across their full width when transported, and stored flat. Surface scratches on PTFE laminates can affect impedance uniformity in microstrip structures if they’re in the active circuit area.

Drilling Parameters

Use sharp, new carbide bits. Feed rate and spindle speed must be reduced from FR-4 parameters — soft PTFE tends to smear rather than cut cleanly with dull or fast-moving drill geometry. Entry material (phenolic or aluminum) is important for clean hole entry, and exit backup prevents burring and tearout on the underside. Reduce hit count per bit drastically compared to FR-4 standards. The softer DiClad 880 is more sensitive to drill bit wear than DiClad 522/527 — fresh bits make a measurable difference in hole wall quality.

PTFE Surface Activation Before Plating

Raw PTFE is chemically inert — electroless copper will not adhere without activation. Sodium naphthalene etching or plasma etching is required to activate the PTFE surface before metallization. This step is non-negotiable, and inadequate activation is the root cause of nearly all pad-lifting and via delamination failures in PTFE PCBs. Insist on seeing your fabricator’s written activation procedure and ensure it is validated for DiClad 880 specifically.

Pre-Bake Protocol

Pre-bake panels at 105°C for 2–4 hours before reflow. DiClad 880’s water absorption is just 0.02%, but any moisture present during the rapid thermal ramp of lead-free reflow will flash to steam and can initiate delamination at the copper-PTFE interface. The pre-bake is cheap insurance.

Impedance Control Considerations

DiClad 880 offers two Dk options: 2.17 and 2.20. Always request the measured Dk certificate from your material batch and use that actual value in your field solver. The difference between 2.17 and 2.20 shifts a 50-ohm microstrip calculation on a 20 mil core by roughly 1.5–2 ohms — not negligible if you’re holding ±5 ohm tolerance on an impedance-controlled layer.

For fabrication support with DiClad 880 and guidance on PTFE-specific process requirements, working with a specialist in Arlon PCB manufacturing is the fastest way to avoid process-related yield and reliability problems on your first build.

Signal Propagation Speed: Why DiClad 880’s Low Dk Matters

One aspect that doesn’t get enough attention in material comparison articles is what a low Dk actually means for signal propagation velocity. The propagation velocity of a signal in a transmission line is inversely proportional to the square root of the effective dielectric constant. Lower Dk means faster propagation.

Material	Dk @ 10 GHz	Relative Propagation Speed (% of c)
Arlon DiClad 880	2.17	~67.9%
Rogers RT/duroid 5880	2.20	~67.4%
Arlon DiClad 870	2.33	~65.5%
Arlon DiClad 522/527	2.50	~63.2%
Rogers RO4350B	3.48	~53.6%
Standard FR-4	~4.5	~47.1%

The difference between DiClad 880 (Dk 2.17) and FR-4 (Dk ~4.5) is a 44% faster propagation speed. In a radar processor where time-of-flight accuracy is directly tied to range resolution, or in a phased array where phase matching across thousands of elements depends on controlled propagation delay, this difference is system-critical rather than a spec chart curiosity.

Useful Resources for Engineers Working With Arlon DiClad 880

Resource	Description	Link
Official DiClad Family Datasheet (PDF)	Full Arlon DiClad 880/870/522/527 comparative spec table from RS-online	docs.rs-online.com (PDF)
Arlon Microwave Materials Guide (PDF)	Complete guide to all Arlon laminates including CuClad, CLTE, IsoClad, DiClad	integratedtest.com (PDF)
Rogers DiClad 870/880 Product Page	Official Rogers/Arlon DiClad 870 and 880 product page with laminate properties tool	rogerscorp.com
MatWeb DiClad 880 Material Entry	Searchable material property database for DiClad 880	matweb.com
LookPolymers DiClad 880 Entry	Aggregated property data and application overview for DiClad 880	lookpolymers.com
Arlon EMD Official Website	Manufacturer’s official documentation portal for all Arlon laminates	arlonemd.com
Arlon Laminate Guide — Everything You Wanted to Know (PDF)	Comprehensive Arlon technical guide covering laminate selection, PTFE properties, and fabrication	arlonemd.com (PDF)
everythingRF DiClad 880-IM Page	Product listing with specifications and quote request for DiClad 880-IM variant	everythingrf.com

Frequently Asked Questions About Arlon DiClad 880

1. What is the difference between DiClad 880 Dk 2.17 and Dk 2.20?

Both are valid DiClad 880 product options — they differ slightly in their fiberglass/PTFE ratio, with the 2.17 version containing fractionally less fiberglass. From a practical design standpoint, the Dk 2.17 version will produce trace widths approximately 1.5–2% wider for the same characteristic impedance, which has a marginal effect on conductor resistance and is generally not significant in most designs. The mechanical properties are essentially identical between the two. Availability of each Dk variant varies by thickness and by distributor. For most applications, either version performs equivalently. When tight phase matching across many elements is required, ensure your full panel run uses material from the same batch and the same nominal Dk to avoid phase dispersion between different material lots.

2. When is DiClad 880 genuinely necessary versus DiClad 870?

DiClad 880 is genuinely necessary when your design fails its electrical requirements on DiClad 870 and the failure mode is dielectric loss rather than mechanical or dimensional factors. Concretely, this means: operating frequencies above 20 GHz where Df 0.0013 is generating unacceptable insertion loss in long trace runs; ultra-low-noise receiver front ends where every fractional dB in the input matching network directly degrades noise figure; or designs where the propagation speed improvement from Dk 2.17 versus 2.33 is a hard system requirement. For most designs operating below 15 GHz with reasonable loss budgets, DiClad 870 delivers adequate electrical performance with meaningfully better mechanical properties and a more forgiving fabrication process. Start with DiClad 870 and move to DiClad 880 only when your insertion loss analysis or phase velocity requirements justify the mechanical trade-off.

3. How does the woven glass structure of DiClad 880 affect mmWave performance?

At millimeter-wave frequencies (30 GHz and above), the periodic structure of woven fiberglass creates localized Dk variations — regions slightly richer in glass have higher Dk, regions between glass bundles are slightly lower. This periodic variation can cause the microwave equivalent of Bragg reflections at certain frequencies, and it creates phase non-uniformity in large-format boards. This is the primary argument for random-fiber materials like Rogers RT/duroid 5880 over woven-glass materials at the highest frequencies. For most designs up to Ka-band (26.5–40 GHz), the woven glass effect in DiClad 880 is manageable. For V-band (50–75 GHz) designs — particularly large phased arrays where this effect integrates across many unit cells — random-fiber substrates may offer better phase uniformity. For single-chip or small-module work at V-band, DiClad 880 is still widely used effectively.

4. Can DiClad 880 be used in lead-free and high-temperature assembly processes?

Yes. PTFE has a continuous use temperature well above lead-free reflow peak temperatures (typically 250–260°C peak). The substrate will not degrade during standard lead-free assembly profiles. The main risk is moisture-driven delamination during the rapid ramp to reflow temperature — which is eliminated by the standard pre-bake protocol (105°C for 2–4 hours). DiClad 880 is also compatible with multiple reflow cycles without substrate degradation, though each thermal cycle above room temperature does stress plated through-holes due to Z-axis CTE expansion (252 ppm/°C for DiClad 880). For assemblies undergoing many reflow cycles, via design robustness should be evaluated against your specific thermal profile.

5. What surface finish options are recommended for DiClad 880 at high frequencies?

ENIG (Electroless Nickel Immersion Gold) is the standard choice and works well for most applications. However, at frequencies above 15–20 GHz, the nickel layer in ENIG introduces additional conductor loss due to nickel’s higher resistivity and magnetic permeability compared to copper. For designs at Ka-band and above, direct immersion gold (without the nickel barrier) — sometimes called ENEPIG (Electroless Nickel Electroless Palladium Immersion Gold) — or immersion silver are preferred options that reduce the high-frequency conductor loss at the pad surface. HASL is not appropriate for DiClad 880 — the high-temperature, turbulent solder process used in HASL is particularly aggressive on soft PTFE substrates and can cause pad lifting. OSP is occasionally used where low pad surface loss is important and environmental exposure is controlled.

Conclusion

Arlon DiClad 880 is the right answer to a specific engineering question: what is the best substrate when the lowest dielectric constant and lowest dissipation factor in the fiberglass-reinforced PTFE category are genuinely required? With Dk 2.17/2.20 and Df 0.0009 at 10 GHz, it delivers the fastest signal propagation speed and lowest dielectric insertion loss of any DiClad product — values that are directly system-critical in millimeter-wave circuits, ultra-low-noise receiver chains, and long phased array feed networks where loss budget has been exhausted on every other material option.

The trade-off is real: reduced mechanical rigidity (tensile modulus 267 kpsi vs 706 kpsi for DiClad 522), higher Z-axis CTE (252 ppm/°C), and a more demanding fabrication process. DiClad 880 is not the right material for an application that could succeed with DiClad 870. It is precisely the right material for the applications that need every last decimal point of electrical performance it offers.

For sourcing DiClad 880, validating your stack-up with the correct measured Dk, and working with a fabricator who has documented PTFE processing experience, connecting with an expert Arlon PCB manufacturer will save you significant development time and first-build yield risk.