Arlon AD450 PCB Laminate: Dielectric Properties, Datasheet & Applications

If you’ve been designing high-frequency circuits that need to work in the 4–18 GHz range with compact form factors, or if you’re migrating a design off FR-4 because insertion loss is becoming a problem above a few gigahertz, the Arlon AD450 laminate deserves a serious look. It occupies a specific and genuinely useful position in the Arlon AD Series lineup: a dielectric constant of 4.5 that closely tracks standard FR-4’s nominal Dk, combined with a PTFE-based loss tangent that leaves FR-4’s dissipation factor in the dust at microwave frequencies. For engineers trying to move a design to higher frequency performance without rearchitecting the entire board geometry, that combination is exactly what they need.

This guide covers the full Arlon AD450 picture — what it is, where it came from, the verified property set from the official Arlon datasheet, how it compares to the materials it most commonly competes with and replaces, design and fabrication considerations, and the resources you need to work with it effectively.

What Is Arlon AD450? Background and Material Development

Arlon Electronic Materials has been producing specialty microwave laminates since 1969, with the AD Series representing its cost-optimized woven fiberglass PTFE composite family for commercial wireless and microwave applications. Rogers Corporation acquired Arlon in 2015, and Arlon PCB AD450 now sits under Rogers’ Advanced Electronics Solutions division, retaining the original Arlon part number and brand designation.

The “AD” prefix stands for Antenna Dielectric — though in practice AD450 sees use well beyond antenna work. The “450” directly reflects the nominal dielectric constant of 4.5. Understanding where AD450 fits within the broader AD Series requires knowing what it was designed to replace.

AD450 was developed specifically as the woven fiberglass successor to the Arlon AR450. The AR450 was a non-woven fiberglass reinforced PTFE composite with similar electrical properties, but the non-woven construction had inherent disadvantages in thickness uniformity, dimensional stability across the panel, and manufacturing cost. The shift from non-woven to woven fiberglass reinforcement in AD450 delivered three concrete improvements: better dielectric constant uniformity across a production panel, better dimensional stability during processing, and reduced manufacturing cost — all without changing the fundamental electrical performance.

The construction is a woven fiberglass-reinforced, ceramic-filled, PTFE-based composite. As with all members of the AD Series ceramic-filled family, the three-component system works together: PTFE provides the inherently low-loss dielectric foundation, woven fiberglass reinforcement delivers mechanical rigidity and in-plane dimensional stability, and microdispersed ceramic filler drives the higher Dk value and influences the thermal properties. The ceramic loading level required to achieve Dk = 4.5 is substantially higher than in the AD250C/AD255C materials, which is reflected in the different thermal coefficient and specific gravity that AD450 exhibits compared to its lower-Dk AD Series siblings.

Arlon AD450 Full Electrical Properties: Verified Datasheet Data

The following property values are drawn directly from the official Arlon Microwave & RF Materials Guide — the most authoritative consolidated source for the full AD Series property matrix, covering all AD Series products in a single verified reference document.

Key Electrical Properties

Property	Value	Condition	Test Method
Dielectric Constant (Dk)	4.50	10 GHz	IPC TM-650 2.5.5.5
Dissipation Factor (Df)	0.0035	10 GHz	IPC TM-650 2.5.5.5
Thermal Coefficient of εr (TCεr)	−233 ppm/°C	—	IPC TM-650 2.5.5.5
Flammability	V-0	—	UL 94
NASA TML (Total Mass Loss)	0.01	%	NASA SP-R-0022A
NASA CVCM	0.01	%	NASA SP-R-0022A

The Dk of 4.50 is one of the most commercially important properties of this material. Standard FR-4 runs in the range of 4.0–4.5 at 1 MHz — though FR-4’s Dk drops significantly as frequency increases, typically landing around 3.8–4.2 at microwave frequencies depending on the specific grade and weave. AD450’s Dk of 4.50, measured at 10 GHz, is both a higher absolute value and — critically — far more stable across frequency than FR-4, as confirmed in the material’s Dk versus frequency graphs in the official datasheet which show the Dk changing by less than ±2% from 0 to 30 GHz.

That frequency stability is what enables direct dimensional transfer of FR-4 designs. When migrating from FR-4 to AD450, the trace widths, resonator dimensions, and antenna element sizes calculated for FR-4’s nominal Dk can be transferred with minimal modification, because AD450’s effective Dk at the target operating frequency is close to FR-4’s lower-frequency nominal value, and remains stable rather than shifting with frequency the way FR-4 does.

The dissipation factor of 0.0035 at 10 GHz is slightly higher than sister products AD410 and AD430 (which achieve 0.003) but dramatically lower than any FR-4 grade. Standard FR-4 Df at microwave frequencies runs 0.015–0.025 depending on grade — roughly five to seven times higher than AD450’s value. For a typical 100 mm microstrip line at 10 GHz, the dielectric loss difference between AD450 and FR-4 represents multiple dB of insertion loss — a gap that matters enormously in receiver front ends, antenna feed networks, and any circuit where noise figure or gain flatness is specified.

The TCεr Value: A Critical Design Parameter

The thermal coefficient of the dielectric constant (TCεr) of −233 ppm/°C is the highest-magnitude TCεr in the AD Series for the standard Dk-range materials. It tells you that as temperature rises, the dielectric constant of AD450 decreases at 233 parts per million per degree Celsius.

For comparison, AD350A, AD410, and AD430 all achieve TCεr values of −55 ppm/°C — roughly four times more stable over temperature. The AD450’s relatively high TCεr is a direct consequence of the ceramic formulation and loading level used to reach Dk = 4.5. Engineers designing temperature-sensitive resonant structures — narrowband bandpass filters, patch antennas with tight frequency tolerance, oscillator resonators — need to account for this Dk shift in their design margin. Across a −40°C to +85°C operating range, the Dk change due to TCεr alone is approximately 0.13, which shifts the center frequency of a 10 GHz filter by 150–200 MHz. For wideband designs that’s typically fine; for narrowband channelising filters it requires deliberate compensation or a different material choice.

Arlon AD450 Thermal and Mechanical Properties

All values in the following tables are from the verified Arlon product overview matrix in the official Arlon Microwave & RF Materials Guide.

Thermal and Dimensional Properties

Property	Value	Units
CTE — X-axis	8	ppm/°C
CTE — Y-axis	11	ppm/°C
CTE — Z-axis	42	ppm/°C
Thermal Conductivity	0.38	W/m·K
Specific Gravity	2.45	g/cm³
Water Absorption	0.07	%
Flammability	V-0 (UL 94)	—

Mechanical Properties

Property	Value	Units
Peel Strength (1 oz copper)	>12	lbs/in
NASA TML	0.01	%
NASA CVCM	0.01	%

The Z-axis CTE of 42 ppm/°C is substantially lower than unfilled PTFE/glass laminates, which typically measure 150–250 ppm/°C in the Z-direction. That improvement directly reduces plated through-hole barrel stress during thermal cycling — the primary reliability mechanism for PTH fatigue failure in high-temperature operating environments. Standard plain PTFE/glass laminates expand 4–6× more per degree Celsius in the Z-direction compared to AD450, a difference that accumulates into PTH barrel cracking after repeated thermal cycles in any design that experiences power cycling, solar loading, or seasonal temperature variation over its service life.

The X/Y CTE asymmetry (8 vs. 11 ppm/°C) is characteristic of woven fiberglass reinforced PTFE composites, where warp and fill fibre densities differ. Both values are well below copper’s CTE of ~17 ppm/°C, making solder joint reliability in SMT assemblies on AD450 generally good across the standard operating temperature range.

The very low NASA outgassing values — 0.01% TML and 0.01% CVCM — deserve specific attention. NASA’s standard material acceptance limits for spacecraft use are typically TML ≤ 1.0% and CVCM ≤ 0.1%. AD450’s measured values are 100× and 10× below those limits, respectively, confirming its suitability for space-qualified hardware. The fact that Arlon measures and publishes these values signals that AD450 has been actively evaluated and used in space and aerospace programs — a meaningful endorsement of the material’s chemical stability.

The thermal conductivity of 0.38 W/m·K is above plain PTFE/glass (typically 0.20–0.26 W/m·K) and adequate for passive microwave circuits. For active circuit designs where device junction temperature management is a primary design driver, AD350A (0.45 W/m·K) or AD410/AD430 (0.46 W/m·K) offer slightly better thermal conduction from device to board edge or heatsink.

Available Configurations: Thickness and Copper Options

Standard Dielectric Thicknesses

AD450 is available from 0.010″ starting thickness, enabling compact and miniaturised circuit construction. Large panel sizes up to 36″ × 48″ are available, supporting high-element-count antenna arrays and large-format circuit boards.

Thickness (inches)	Thickness (mm)	Typical Use
0.010″	0.254	Ultra-compact filters, miniaturised antenna patches
0.020″	0.508	Compact microstrip circuits, MMIC support boards
0.030″	0.762	Standard microstrip feed networks and antenna work
0.060″	1.524	Thicker power combiner boards and feed networks
0.062″	1.575	Patch antenna arrays requiring specific resonant thickness

Copper Foil Options

Foil Type	Weight Options	Notes
Electrodeposited (ED) copper	½ oz, 1 oz, 2 oz	Standard supply configuration
Rolled copper	Available on request	Lower roughness, better conductor loss above 5 GHz
Heavy metal ground plane	Al, Cu, Brass plate	Integral heatsink for high-power active circuit modules

Arlon AD450 vs. Competing RF Laminates

Understanding where AD450 sits relative to competing materials clarifies when it should be selected and when an alternative fits better.

Material	Dk (10 GHz)	Df (10 GHz)	TCεr (ppm/°C)	Z-CTE (ppm/°C)	TC (W/m·K)	Processing
Arlon AD450	4.50	0.0035	−233	42	0.38	PTFE
Arlon AD430	4.30	0.003	−55	40	0.46	PTFE
Arlon AD410	4.10	0.003	−55	40	0.46	PTFE
Arlon AD350A	3.50	0.003	−55	35	0.45	PTFE
Rogers RO4350B	3.48	0.0037	~−50	46	0.69	FR4-like
Taconic RF-45	4.50	0.0037	—	~50	0.30	PTFE
Standard FR-4	~4.2 at 1 GHz	0.015–0.025	Large negative	50–70	0.25–0.35	FR4

AD450 vs. AD410/AD430: This is the most important internal comparison and its answer is non-obvious. AD410 and AD430 both achieve lower Df (0.003 vs. 0.0035) and a far more stable TCεr (−55 vs. −233 ppm/°C) at Dk values of 4.10 and 4.30 respectively. The Dk difference between AD430 (4.30) and AD450 (4.50) is about 4.4% — which translates to roughly a 2.2% difference in resonator dimensions. For many designs that difference falls within process tolerance. Choosing AD430 over AD450 buys a four-fold improvement in TCεr and slightly better Df at the cost of a small geometric scaling adjustment — a trade-off that is clearly worthwhile for any temperature-sensitive design.

AD450 vs. FR-4: This is AD450’s defining competitive positioning. With Dk = 4.5 at 10 GHz matching FR-4’s nominal low-frequency Dk, most FR-4 designs can be dimensionally transferred to AD450 with minimal trace and element resizing. The benefit is a loss tangent 4–7× lower than FR-4, improving insertion loss, noise figure, and power efficiency at any operating frequency above approximately 500 MHz. For designs that have outgrown FR-4’s loss performance but where the engineer wants to avoid resizing all circuit geometries, AD450 is the path of least resistance among PTFE-based alternatives.

AD450 vs. RO4350B: These materials are not direct dimensional substitutes — RO4350B sits at Dk = 3.48 vs. AD450’s 4.50, so they produce different trace geometries for the same impedance. RO4350B has better TCεr stability and significantly higher thermal conductivity (0.69 W/m·K), and its FR4-compatible processing is a major manufacturing advantage. AD450’s advantages over RO4350B are the higher Dk enabling more compact geometries, and the PTFE-based chemical stability including the space-grade outgassing performance that RO4350B’s hydrocarbon thermoset construction cannot match.

AD450 PCB Design Considerations

Impedance and Trace Geometry Planning

With Dk = 4.50, AD450 produces narrower 50Ω traces and more compact resonant structures than lower-Dk laminates. On a 0.030″ substrate with 1 oz copper, a 50Ω microstrip trace runs approximately 0.55–0.60 mm wide. This narrowing compared to AD250C or AD350A is one reason engineers choose AD450 when board density is constrained — more circuit elements per unit area fit in the same footprint. Always verify impedance with an electromagnetic field solver at microwave frequencies rather than relying on closed-form approximations, which become less accurate as trace geometries narrow.

Compact Circuit Design at Dk 4.5

The higher Dk is a design tool as much as it is a nominal specification. For patch antenna miniaturisation: the resonant dimension of a half-wave patch scales inversely with the square root of Dk. Moving from Dk = 2.5 to Dk = 4.5 reduces the patch element dimension by approximately 25% — meaningful in dense phased array designs. For coupled-resonator filters, physical filter length scales similarly, enabling multi-section microwave filter designs that fit in the space a lower-Dk alternative would require significantly more board area to implement.

Managing TCεr in Temperature-Sensitive Circuits

For broadband designs with >10% fractional bandwidth, the Dk shift from TCεr over a ±50°C temperature range typically stays within the circuit passband and requires no special compensation. For narrowband filters and precision resonant structures, budget the frequency shift across the full operating temperature range during design. If the required frequency stability cannot be achieved with AD450’s TCεr of −233 ppm/°C, AD430 (TCεr = −55 ppm/°C, Dk = 4.30) is the nearest alternative with better temperature stability at comparable Dk.

Layout for Low Conductor Loss

At frequencies above 5 GHz, skin effect concentrates RF current at the copper surface, making conductor roughness a meaningful contributor to insertion loss. For AD450 designs above 5 GHz where loss budget is tight, specifying rolled copper rather than standard ED copper reduces surface roughness and the associated skin-effect losses. The benefit is proportionally larger for the narrower traces that come with AD450’s Dk = 4.5, since the conductor loss per unit length is higher on narrower traces.

PTFE Fabrication Requirements for AD450

AD450 is compatible with processing used for standard PTFE-based PCB substrates — the same process framework as all other PTFE composite laminates in the AD Series. Three fabrication steps are non-negotiable and separate a reliable AD450 board from one that will fail in service.

Drilling with PTFE-tuned parameters: The PTFE fluoropolymer matrix is soft and smears under FR-4 drill speeds. Dedicated PTFE drilling parameters — lower spindle speed, sharp carbide tooling, controlled chip load — are required to produce clean hole walls. Bell-mouthing and smearing both compromise copper plating adhesion.

Through-hole surface activation before plating: PTFE is chemically inert — copper won’t adhere to it without surface treatment. Sodium naphthalene chemical etch or CF4/O2 plasma etch both break up the fluorine-carbon bonds at the hole wall, creating adhesion sites for the electroplated copper. Skipping this step produces boards that pass incoming inspection but fail in service through PTH delamination during thermal cycling. There is no workaround — surface activation is mandatory.

PTFE-compatible bonding films for multilayer construction: Standard FR-4 prepreg cures at incompatible temperatures and produces inadequate adhesion when used with PTFE cores. Fluoropolymer bonding films (FEP or equivalent) are the correct inter-layer bonding approach. Work with your fabricator on bonding film selection before finalising a multilayer AD450 stackup.

Typical Applications of Arlon AD450

FR-4 Replacement in Higher-Frequency Applications: The headline use case. When a design running on FR-4 starts showing unacceptable insertion loss or noise figure degradation as operating frequency increases beyond 2–3 GHz, AD450’s Dk proximity to FR-4 minimises the geometric redesign effort while delivering a 4–7× reduction in loss tangent.

Circuit Board Miniaturisation: Dk = 4.5 enables more compact filter, matching network, and antenna element geometries than lower-Dk alternatives at the same operating frequency. In space-constrained PCB designs, this size reduction is often the enabling factor.

Wideband Antenna Applications: The stable Dk versus frequency characteristic makes AD450 reliable for wideband antenna designs where consistent impedance match and radiation pattern across a broad operating band depend on substrate Dk stability.

Multimedia Transmission Systems: AD450 is explicitly listed in Arlon’s documentation for multimedia transmission system applications — commercial point-to-point and point-to-multipoint systems in the 5–18 GHz range where FR-4 loss is prohibitive.

Aerospace and Space Hardware: The low NASA outgassing values (TML = 0.01%, CVCM = 0.01%) place AD450 well within space qualification limits. Programs requiring materials certification against NASA outgassing standards will find AD450’s published data significantly simplifies the qualification process.

Low Noise Amplifier Substrates: The combination of low Df, compact geometry at high Dk, and acceptable thermal performance makes AD450 a viable LNA substrate for systems operating above 3 GHz where FR-4 loss would degrade noise figure.

Useful Technical Resources for Arlon AD450

Resource	Description	Link
Rogers AD450 Product Page	Official Rogers product page with downloadable datasheet	rogerscorp.com/ad450
Arlon Microwave & RF Materials Guide PDF	Official full AD Series property matrix with verified AD450 data	integratedtest.com/ArlonMaterials.pdf
Legacy Arlon AD Series Brochure (Cirexx)	Original multi-product AD Series PDF with Dk vs. frequency graphs	cirexx.com/AD-Series.pdf
RF Globalnet AD450 Listing	Material description and datasheet for the RF engineering community	rfglobalnet.com
Rogers MWI-2010 Impedance Calculator	Microstrip and stripline impedance calculator for Rogers/Arlon materials	Rogers Calculator
Rogers Laminate Properties Tool	Interactive comparison tool for all Rogers and Arlon materials	Rogers Laminate Tool
LookPolymers AD450A Entry	Material composition and property entry with application notes	lookpolymers.com
IPC TM-650 Test Methods Library	Standard test methods referenced in the AD450 property table	ipc.org
Cirexx Arlon Materials Overview	Fabricator context for Arlon material families with application guidance	cirexx.com/arlon-materials

Arlon AD450 Frequently Asked Questions

Q1: What makes Arlon AD450 different from the AR450 it was designed to replace?

AD450 replaces the older AR450, which used non-woven fiberglass reinforcement. The shift to woven fiberglass in AD450 delivers three measurable improvements: better Dk uniformity across a production panel, better dimensional stability during etch and lamination processing, and lower manufacturing cost. The fundamental electrical characteristics — Dk, Df, and operating frequency range — remain equivalent between the two materials. Designs qualified on AR450 can transition to AD450 through requalification rather than a full redesign, and most modern PTFE-capable fabricators have already moved to stocking AD450 rather than AR450.

Q2: Is AD450 a practical FR-4 replacement for 5G sub-6 GHz circuit designs?

It is one of the cleaner migration paths. With Dk = 4.5 at 10 GHz closely matching FR-4’s nominal low-frequency dielectric constant, trace widths and element dimensions from an existing FR-4 layout require only minor tuning — not a full redesign. The reward is a loss tangent 4–7× lower than FR-4, delivering significantly better insertion loss performance at 3.5 GHz and 5 GHz operating bands. The practical caveats are PTFE fabrication requirements (the fab shop must have PTFE-capable processes) and the TCεr of −233 ppm/°C, which is acceptable for wideband 5G work but requires evaluation for narrowband filter designs.

Q3: Why is AD450’s TCεr so much higher in magnitude than AD410 and AD430?

AD410 and AD430 use a newer ceramic formulation that achieves improved TCεr control, reaching −55 ppm/°C at Dk values of 4.10 and 4.30. AD450 at Dk = 4.5 uses a different ceramic loading approach that hasn’t been reformulated to the lower TCεr of the newer materials, resulting in −233 ppm/°C. This is clearly visible in the Arlon materials guide where AD350A, AD410, and AD430 all show −55 ppm/°C, while AD450 shows −233 ppm/°C. If low TCεr at approximately Dk 4.3–4.5 is a hard requirement, AD430 (Dk = 4.30, TCεr = −55 ppm/°C) is the practical solution — the 4.4% Dk difference usually falls within geometric design tolerance after minor trace width adjustment.

Q4: What fabrication process does AD450 need, and why can’t FR-4 shops make it?

AD450 requires PTFE-specific fabrication processes at three critical steps. Drilling requires tuned parameters for PTFE’s soft cutting behaviour — lower spindle speeds and sharper tooling than FR-4 — to avoid hole wall smearing that compromises plating adhesion. Through-holes require surface activation with sodium naphthalene or CF4/O2 plasma etch before copper plating, because PTFE’s fluoropolymer surface won’t accept copper adhesion without breaking up the fluorine-carbon bonds. Multilayer construction requires PTFE-compatible bonding films rather than FR-4 prepreg, which is thermally and chemically incompatible with PTFE lamination. Shops without documented PTFE process experience will produce boards that look fine in inspection but fail in the field.

Q5: Does Arlon AD450 qualify for space and aerospace applications?

Yes. AD450’s NASA outgassing data — TML of 0.01% and CVCM of 0.01% — places it comfortably within the acceptance limits used for space hardware qualification. NASA’s standard material requirements for use near sensitive spacecraft surfaces are typically TML ≤ 1.0% and CVCM ≤ 0.1%. AD450’s measured values are 100× and 10× below those limits respectively. This performance comes directly from PTFE’s chemically stable, low-volatility molecular structure. For space program materials qualification, AD450’s published NASA data is a significant advantage — it simplifies the materials certification process and provides documented evidence of compliance that many alternative laminates cannot supply.