Taconic PCB materials guide for 2025: full breakdown of TLY-5, RF-35, TSM-XT product families, Dk/Df specs, fabrication steps, and real RF applications.

If you have ever priced a high-frequency board and watched the quote triple when you switched from FR-4 to something more exotic, you have already met the world of Taconic PCB materials. After twenty years of specifying laminates for everything from satellite uplinks to 77 GHz automotive radar, I can tell you Taconic is one of three names that dominates any serious RF bill of materials — and in my experience, often the most underrated of the three.

This guide walks through the complete Taconic lineup as it stands in 2025, with the numbers you actually need, the processing gotchas nobody mentions on the datasheet, and the application contexts where each material earns its price premium. No marketing fluff, no repeated taglines — just what a working RF engineer needs to know before committing to a stack-up.

What Are Taconic PCB Materials?

Taconic PCB materials are high-performance laminates and prepregs originally developed by Taconic Advanced Dielectric Division, a U.S. company founded in 1961 in Petersburgh, New York. In 2019 AGC Inc. (the Japanese glass and electronics conglomerate) acquired the business, and the product line now ships under the AGC Multi Material banner — though virtually everyone in the industry still calls them Taconic. The datasheets still carry the Taconic name, the part numbers are unchanged, and the manufacturing continues from the same Petersburgh and Mullingar, Ireland facilities.

The core technology is coated PTFE (polytetrafluoroethylene, sometimes called Teflon after the DuPont trademark). Taconic was one of the first companies to figure out how to evenly coat woven glass fabric with PTFE, and that patent heritage still shows in their laminate consistency. Where competitors sometimes use chopped fiber or random mat reinforcement, Taconic’s bread and butter is woven glass plus PTFE — sometimes with ceramic fill added to tune the dielectric constant.

The result is a family of laminates that hit four properties at once: very low dielectric constant (Dk), very low dissipation factor (Df), excellent dimensional stability, and near-zero moisture absorption. For any RF board above roughly 3 GHz, those are the numbers that keep insertion loss predictable and impedance flat.

Taconic PCB materials are most commonly specified for microwave and millimeter-wave applications — 5G base stations, automotive radar, satellite communications, phased arrays, and RF test equipment. They compete directly with Rogers Corporation’s RO3000 and RO4000 series, and with Isola’s Astra MT and IS680 products.

A Quick Note on the AGC Acquisition

Because the AGC acquisition happens to come up in every procurement call, worth addressing: nothing about the material specifications or availability has changed. AGC sometimes relabels datasheets with their branding, but the part numbers (TLY-5, RF-35, TSM-DS3, and so on) are unchanged, and the materials are produced on the same lines by the same engineers. If your fabricator asks whether you want “Taconic” or “AGC” material, they are the same thing.

The Four Key Properties That Define Taconic PCB Materials

Before diving into the product families, it helps to understand what the Taconic datasheets are optimizing for. Every laminate exists on a trade-off surface between these four parameters, and choosing the right Taconic grade is really a matter of picking which properties you want to prioritize.

Property	What It Controls	Typical Taconic Range	Why It Matters
Dielectric Constant (Dk)	Signal propagation velocity and trace geometry	2.17 to 10.2	Determines trace width for a target impedance; lower Dk means faster signals
Dissipation Factor (Df)	How much signal energy is lost as heat	0.0009 to 0.0037	Direct driver of insertion loss; Taconic hits values competitors struggle to match
Thermal Conductivity	How efficiently the substrate moves heat away	0.22 to 0.71 W/m·K	Critical for power amplifiers; pure PTFE grades are insulative, TC variants help
Moisture Absorption	Water uptake under humidity	<0.02% to 0.04%	Taconic’s strongest property — essentially immune to humidity-driven Dk drift

The combination that makes Taconic distinctive is low Df with very low moisture absorption. Hydrocarbon-ceramic laminates from some competitors achieve comparable Df numbers on a dry board, but their Dk drifts measurably after humidity exposure. Taconic PTFE simply does not care about humidity — which is why it shows up in outdoor antennas, avionics, and any application where the board lives in a weather-exposed enclosure.

Taconic PCB Material Product Families

Taconic organizes their portfolio into several product families, each built on a different base chemistry. Understanding these families is the fastest way to navigate the catalog, because within each family the part numbers mostly differ by Dk value or by thickness range.

PTFE/Woven Glass Family — TLY, TLX, TLE, TLC Series

The TLY, TLX, TLE, and TLC laminates are the original Taconic products — pure PTFE resin impregnated into woven fiberglass. No ceramic fill. This gives the lowest possible Df (around 0.0009 at 10 GHz), at the cost of a Dk fixed at the 2.17 to 2.65 range set by PTFE and glass alone.

These are the go-to materials when loss is the dominant concern and you can design around a low Dk. Think satellite communications, phased arrays, mmWave sensors, and any application where the wavelength is short enough that a lower Dk actually helps you fit the circuit.

Part Number	Dk @ 10 GHz	Df @ 10 GHz	Composition	Typical Use
TLY-3	2.33	0.0012	PTFE/Woven glass	General mmWave, antennas
TLY-5	2.20	0.0009	PTFE/Woven glass	77 GHz radar, satellite, filters
TLY-5A	2.17	0.0009	PTFE/Woven glass (lightweight)	Aerospace, precision mmWave
TLX-0	2.45	0.0019	PTFE/Woven glass	Lower-cost microwave
TLX-6	2.65	0.0019	PTFE/Woven glass	Commercial microwave
TLX-7	2.60	0.0019	PTFE/Woven glass	General RF
TLX-8	2.55	0.0019	PTFE/Woven glass	High-volume RF
TLX-9	2.50	0.0019	PTFE/Woven glass	RF couplers, filters
TLE-95	2.95	0.0028	PTFE/Woven glass	Digital/RF hybrid
TLC-27	2.75	0.0028	PTFE/Woven glass	Power amplifier substrates
TLC-30	3.00	0.0030	PTFE/Woven glass	General microwave
TLC-32	3.20	0.0030	PTFE/Woven glass	Higher-Dk applications

The TLY-5 is probably the single most-specified Taconic part number I see. At Dk 2.20 and Df 0.0009, it sits at the sweet spot where most 77 GHz automotive radar antennas land, and the 0.02% moisture absorption makes it reliable in the under-hood thermal environment.

TLY-5A is the tighter-tolerance variant — same Df, but Dk spec’d to 2.17 ± 0.02. If you are building a precision phased array where element-to-element Dk variation matters, you pay the premium for TLY-5A and get it.

Ceramic-Filled PTFE Family — RF Series

The RF series takes the TLY/TLX base chemistry and adds ceramic filler. This does three things: raises the Dk to whatever you want (from 2.94 all the way to 10.2), improves thermal conductivity, and improves dimensional stability. The trade-off is slightly higher Df compared to the pure-PTFE grades, though still well below FR-4.

RF-35 is the workhorse of this family, and probably the most common Taconic part number in 5G sub-6 GHz base station hardware. It is organic-ceramic filled with woven glass reinforcement, and the combination processes much more like FR-4 than pure PTFE does. That makes it the Taconic grade most fabricators are comfortable with.

Part Number	Dk @ 10 GHz	Df @ 10 GHz	Thermal Cond. (W/m·K)	Typical Use
RF-30	3.00	0.0014	0.40	Microwave circuits
RF-30A	3.00	0.0013	0.40	Updated RF-30
RF-35	3.50	0.0018	0.24	5G base stations, general RF
RF-35A2	3.50	0.0018	0.24	Improved RF-35 variant
RF-35P	3.50	0.0025	0.24	Prepreg for hybrid stacks
RF-35TC	3.50	0.0011	0.71	Power amps, heat dissipation
RF-35HTC	3.50	0.0012	0.85	High-thermal-conductivity
RF-41	4.10	0.0035	0.44	Compact RF design
RF-43	4.30	0.0033	0.44	Digital/RF mixed
RF-45	4.50	0.0037	0.44	High-Dk microwave
RF-60A	6.15	0.0028	0.50	Small-form-factor RF
RF-301	2.97	0.0017	—	Updated RF-30 class
CER-10	10.0	0.0035	0.63	Capacitors, very small circuits

Two entries on that table deserve special attention. RF-35TC is the “TC” thermally-conductive variant — same electrical properties as RF-35, but with thermal conductivity tripled. For power amplifier modules where you need to pull heat out through the substrate, RF-35TC is worth the price jump. It also drops Df to 0.0011, which is noticeably better than standard RF-35.

CER-10 is the oddball: Dk of 10.0, about four times higher than the rest of the Taconic range. At that Dk, trace widths for 50-ohm impedance get very small, which lets you shrink circuit area dramatically. It shows up in tuning elements, miniaturized filters, and applications where physical size matters more than low loss.

Thermoset Microwave Family — TSM Series

The TSM laminates are Taconic’s answer to applications that need PTFE-like electrical performance with easier processing. TSM-DS3 and its variants use a ceramic-filled thermoset resin system that does not require sodium etching before plating — a major fabrication cost saver. They process on standard high-Tg FR-4 lines in most shops.

Part Number	Dk @ 10 GHz	Df @ 10 GHz	Application Focus
TSM-DS3	3.00	0.0011	Digital/RF, backplanes
TSM-DS3b	3.00	0.0011	Updated DS3
TSM-DS3M	3.00	0.0011	mmWave variant
TSM-30	3.00	0.0015	General RF
TSM-XT	2.94	0.0012	Low-loss mmWave to 77 GHz

TSM-XT in particular is worth mentioning because it is optimized for millimeter-wave applications up to 77 GHz at a lower cost than pure PTFE grades. If you are doing volume automotive radar production and the cost of TLY-5 is hurting your BOM, TSM-XT is the first alternative to evaluate.

Hydrocarbon Family — HF Series

The HF series is based on polybutadiene hydrocarbon resin rather than PTFE. Lower cost, FR-4-like processing, and performance that slots between FR-4 and pure PTFE. It competes most directly with Rogers RO4003C / RO4350B.

Part Number	Dk @ 10 GHz	Df @ 10 GHz	Notes
HF300F	3.00	0.0025	Mid-range RF
HF340	3.40	0.0030	General-purpose
HF341	3.41	0.0030	Updated HF340

These are solid materials for RF that does not push past about 10 GHz, where the cost delta to RF-35 is not justified. For most Wi-Fi and sub-6 GHz cellular applications, HF-series boards hit the performance target at a price closer to high-Tg FR-4.

Bonding Films and Prepregs — TacBond and HT Series

You cannot build a multilayer Taconic board without a bonding material, and the TacBond / HT family is what Taconic supplies for that role. The most common is HT1.5, a thermoplastic PTFE-based bonding film with very low loss (Dk 2.35, Df 0.0025). It bonds PTFE layers to each other without requiring an intermediate resin-rich layer.

For hybrid stacks where one Taconic layer bonds to FR-4 or other epoxy materials, standard FR-4 prepregs work fine — the high-frequency signal sits on the ground plane of the Taconic layer and never sees the epoxy.

Part Number	Type	Dk	Df	Typical Use
HT 1.5	Thermoplastic PTFE film	2.35	0.0025	All-PTFE multilayer bonding
RF-35P	Ceramic-filled prepreg	3.50	0.0025	RF-35 multilayer builds
FastRise	Hydrocarbon prepreg	3.28	0.0029	HF-series bonding

Taconic PCB Material Properties in Detail

Numbers on a datasheet only tell part of the story. After twenty years of specifying these materials, here is how the key properties actually behave on real boards.

Dielectric Constant and Stability

The headline Dk values — 2.17 for TLY-5A, 3.50 for RF-35, 2.94 for TSM-XT — are all measured at 10 GHz at room temperature. What matters more in practice is Dk stability: how much that number changes with frequency, temperature, and humidity.

Taconic’s PTFE-based grades hold Dk within about ±0.5% across 1 GHz to 40 GHz. That is roughly half the drift of FR-4, and about the same as Rogers RO4000 series. The temperature coefficient of Dk (TCDk) for TLY-5 is approximately -125 ppm/°C, meaning Dk drops slightly as temperature rises — predictable and compensatable in design.

Dissipation Factor Under Real Conditions

Df numbers on datasheets are measured on dry, freshly-manufactured samples in laboratory conditions. Real boards see humidity, solder flux residues, and thermal cycling. This is where Taconic earns its keep: because PTFE absorbs almost no moisture, the Df stays close to the datasheet value across environmental conditions.

A practical number: for a 10-inch trace at 28 GHz on TLY-5 with half-ounce VLP copper, expect about 0.7 to 0.9 dB of total insertion loss. The same trace on FR-4 would show 4 to 6 dB, depending on which FR-4 variant.

Thermal Conductivity and Power Handling

Standard PTFE is a thermal insulator — around 0.22 W/m·K, which is actually worse than FR-4’s 0.3. This is a problem if you are mounting a 10W power amplifier directly on the board and need to pull heat through the substrate.

Taconic’s answer is the “TC” (thermally conductive) variants, where ceramic fill is optimized for heat flow rather than dielectric tuning. RF-35TC pushes thermal conductivity to 0.71 W/m·K. RF-35HTC goes further, to around 0.85 W/m·K. For comparison, aluminum alloy is 237 W/m·K — the TC variants are not metal-core levels, but they are enough to make substrate-side heat sinking viable for several-watt amplifiers.

Mechanical Properties That Matter

PTFE is a soft material. That has two practical consequences. First, peel strength between copper and substrate tends to be lower than on FR-4 — typically 8 to 12 lbs/inch for 1 oz copper, versus 10 to 15 for FR-4. Not a problem for most designs, but worth knowing before you specify through-hole connectors that will get heavy mechanical cycling.

Second, Taconic boards can stretch during fabrication. For multilayer registration, a good fab will run first-article dimensional scaling tests and apply X/Y compensation to your Gerbers before imaging. Without this, inner-layer pads will miss drill hits in multilayer builds.

Taconic PCB Fabrication — What Your Fab Actually Has to Do

The electrical performance comes with a processing premium. Taconic boards are fabricated using several steps that standard FR-4 shops either do not have equipment for or have to modify significantly. Understanding these steps helps you spec a realistic quote and pick a fabricator who actually knows the material.

Drilling — Slow and Specific

PTFE is soft and rubbery. A standard FR-4 drill program produces smeared hole walls, no matter how sharp the bit. Taconic fabricators run reduced chip loads — roughly 1.0 to 1.5 mil per revolution versus 2 to 3 mil for FR-4 — with specialized drill geometries. Spindle speeds typically drop to 70,000 to 100,000 RPM depending on hole diameter. Drill bit life is often lower, around 1,500 to 3,000 hits per bit before changeout.

For microvias on thin TLY material, laser drilling is the preferred method. Newer TLY-5-L variants with lighter fiberglass are specifically formulated for cleaner laser hole quality.

Sodium Etching — The PTFE-Specific Step

This is the fabrication step that most separates Taconic-capable shops from generic board houses. PTFE is chemically inert and hydrophobic by design — that non-stick property that makes Teflon pans useful is also what stops copper plating from bonding to via walls. Without treatment, the plating solution literally beads up and runs off the hole wall.

The fix is sodium-naphthalene etching. The drilled panel gets dipped in a reactive sodium complex that chemically strips fluorine atoms off the PTFE carbon backbone, leaving a rough, hydrophilic carbon-rich surface that plating can adhere to. Plasma etching can substitute in some cases, but sodium-naphthalene remains the industry standard for reliable through-hole plating on PTFE.

Shops that skip or shortcut this step produce boards that look fine coming out of the line but fail in thermal cycling — trapped moisture in voided plating outgasses during reflow and blows the plating off the via wall. If your fabricator cannot describe their PTFE activation process, find a different fabricator.

Multilayer Lamination

PTFE multilayer builds use higher pressure and longer cycles than FR-4 — typically 500 psi at 375°C for 90 to 120 minutes, versus 300 psi at 190°C for FR-4. Not every press can hit 375°C, which is why some shops quote Taconic work as hybrid builds (Taconic outer layers, FR-4 inner layers) rather than full PTFE stacks.

Hybrid builds are usually the better choice anyway. The RF circuitry sits on outer Taconic layers with a ground plane on the adjacent FR-4 layer, and the digital or power portions live in the cheaper epoxy core. You get RF performance where you need it and pay FR-4 prices for the bulk of the board.

Handling and Storage

Taconic laminates need more care than FR-4. Recommended practice:

Lift panels by two parallel edges, never one corner — the PTFE will stretch under its own weight if hung incorrectly. Store in original vacuum packaging until use, in a climate-controlled area at 18 to 25°C. Use gloves throughout processing; skin oils contaminate PTFE surfaces and cause plating defects. Chemically clean rather than mechanically scrub — the dendritic copper texture on the bond side is what gives the laminate its peel strength, and scrubbing removes it.

Surface Finishes for Taconic PCB Boards

Surface finish choice on a Taconic board matters more than on FR-4 because the finish interacts with both the RF performance and the PTFE surface chemistry. Standard options all work, but each has trade-offs:

Surface Finish	Works on PTFE?	RF Performance	Notes
ENIG (Electroless Nickel Immersion Gold)	Yes	Good	Most common choice; nickel adds slight loss
ENEPIG (adds Palladium)	Yes	Good	Better for fine-pitch wire bonding
Immersion Silver	Yes	Best electrical	Tarnishes; best where boards are hermetically sealed
Immersion Tin	Yes	Good	Limited shelf life, less common for RF
HASL (Hot Air Solder Leveling)	Yes	Adequate	Thermal shock risk on thin PTFE; avoid for <0.010″ material
OSP (Organic Solderability Preservative)	Yes	Excellent	Shortest shelf life, but least RF loss

For most microwave work above 10 GHz, ENIG is the default — it gives a flat, planar surface for consistent RF performance and a gold cap that does not tarnish. Immersion silver offers marginally better conductivity but only if your assembly process can handle it before tarnishing.

Taconic PCB Applications Across Industries

The places Taconic materials ship in volume tell you more about the material than any datasheet. These are the applications where the cost premium over FR-4 is consistently justified.

5G Infrastructure and Cellular Base Stations

The rollout of 5G has been the single biggest driver of Taconic RF-35 and RF-35A2 adoption in the past five years. Power amplifier boards, filter banks, and antenna feed networks for sub-6 GHz 5G all specify RF-35 or RF-35TC on significant portions of the board. For mmWave 5G at 24 to 40 GHz, the TLY series takes over — the lower Dk becomes useful at those frequencies because wavelengths are short enough that smaller circuits actually fit.

Massive MIMO antenna panels, which are the signature hardware of modern 5G deployments, drive particularly high Taconic volume. A typical 64-element antenna panel uses several square feet of RF-35 or RF-35A2 per unit. When you multiply that across the global 5G rollout, it explains why Taconic has been investing in expanded Petersburgh and Suzhou capacity. The 20 percent cost advantage over Rogers at production volumes translates directly to base station margins.

Automotive ADAS Radar at 77 to 79 GHz

Every modern car has between four and twelve radar modules. The 77 GHz long-range forward radar and 79 GHz short-range corner radars almost universally run on PTFE-based substrates, and TLY-5 is one of the top two choices (Rogers RO3003 is the other). At these frequencies, a Dk variation of 0.02 across an antenna array translates to measurable phase error and degraded angular resolution, so the Taconic TLY-5A tolerance matters.

Aerospace and Defense — Radar, Satellite, Phased Arrays

Phased array antennas for radar and satellite communications are prime Taconic territory. The combination of temperature stability, dimensional accuracy, and low moisture absorption matters enormously when your board is sitting on a satellite for ten years with no maintenance. TLY-5 and TLY-5A show up in X-band (8-12 GHz), Ku-band (12-18 GHz), and Ka-band (26-40 GHz) military and commercial satellite hardware.

Medical Imaging and Diagnostic Equipment

MRI coil arrays, high-frequency ultrasound transducers, and RF ablation electrodes all use Taconic substrates for the same reasons satellite builders do: predictable electrical performance over years of use. The low-loss RF path is particularly valuable in medical imaging, where signal-to-noise directly translates to image quality.

Test and Measurement Equipment

Vector network analyzers, spectrum analyzers, and signal generators operating above 20 GHz use Taconic substrates in their internal RF paths. Keysight, Rohde & Schwarz, and Anritsu instruments routinely specify TLY-5 or equivalents for the analyzer front end because the Df stability directly affects measurement accuracy.

Industrial Microwave and RF Power

Magnetron drivers, industrial RF heating, plasma generators, and RF welders use Taconic boards both for the RF performance and for the thermal handling of the TC variants. The moisture immunity becomes important here because industrial environments are rarely climate-controlled.

Taconic vs Rogers vs Isola — Picking Between Them

The question every RF engineer eventually asks: when do you pick Taconic over the competition? Honest answer, based on two decades of mixing them on real designs:

Pick Rogers if you need the widest fabricator network, fastest prototype turnaround, or if your design team already has verified stack-ups in RO4003C/RO4350B. Rogers is the default because every RF fabricator stocks it.

Pick Taconic if the application lives outdoors or in humid environments, if you are building volume production where the 20 to 40 percent cost saving on large laminate purchases matters, or if you need the specific properties of TLY-5/TLY-5A (lowest Dk, lowest Df at mmWave) or RF-35TC (best thermal conductivity at moderate Dk).

Pick Isola if the design is mostly digital with some RF content and you want FR-4-compatible processing throughout. Isola’s low-loss materials (Astra MT77, IS680) process on standard lines and bond cleanly to FR-4 in hybrid stacks.

Criterion	Taconic	Rogers	Isola
Base chemistry	PTFE and ceramic-PTFE	PTFE and hydrocarbon-ceramic	Hydrocarbon and epoxy-based
Df @ 10 GHz (best)	0.0009 (TLY-5A)	0.0009 (RT/duroid 5880)	0.0017 (Astra MT77)
Moisture absorption	<0.02%	0.01-0.10%	0.15-0.35%
Cost vs Rogers	15-30% lower	Baseline	10-20% lower
Fabricator availability	Good	Excellent	Excellent
Max practical frequency	~100 GHz (TLY-5A)	~100 GHz (RT/duroid)	~40 GHz (MT77)

Useful Resources for Taconic PCB Materials

Bookmarks and references I keep close when spec’ing Taconic boards:

Official datasheets and technical documentation:

• AGC Multi Material datasheet library — agc-multimaterial.com/agc-downloads (full Taconic TDS archive)
• Taconic processing guides — specific PDFs for each family (TLY, TLX, RF, TSM) with recommended drill parameters, plating chemistry, and lamination profiles
• AGC’s TLY-5 Processing Guide — the definitive reference for multilayer PTFE fabrication

Product selection references:

• Taconic Advanced PCB Materials Product Selection Guide — one-page summary of all part numbers with typical values
• Microwave Journal material comparison archive — editorial comparisons of Taconic, Rogers, and Isola grades
• San Francisco Circuits PCB Material Reference Guide — side-by-side parametric tables

Fabrication and design tools:

• Polar Si9000 field solver — the industry-standard impedance calculator that supports Taconic material libraries
• Saturn PCB Toolkit — free utility with Taconic Dk presets
• AGC’s online impedance calculator — simple but useful for first-pass trace width sizing

Standards and processing references:

• IPC-6018 — Microwave PCB acceptance criteria
• IPC-TM-650 — Test methods for Dk, Df, and other laminate parameters
• IPC-4103 — Specification for high-speed/high-frequency materials

Where to actually buy:

• Taconic materials are not sold directly to end users in prototype quantities. Buy through your PCB fabricator, or through authorized distributors like Transene Company or Insulectro for North America.

Application notes worth reading:

• AGC’s “RF-35 High Volume Commercial Microwave Laminate” technical bulletin
• AGC’s “TLY Family Low Loss Laminates” product data sheet
• AGC’s “RF-35TC Thermally Conductive Low Loss Laminate” application note — detailed guidance on power amplifier layout

Frequently Asked Questions About Taconic PCB Materials

Is Taconic PCB material better than Rogers for high-frequency design?

Neither is universally better — it depends on what you are optimizing. For pure low-loss performance at mmWave, TLY-5A and Rogers RT/duroid 5880 are essentially equivalent, both at Dk ~2.17 and Df 0.0009. Taconic typically wins on moisture absorption (under 0.02% versus 0.01 to 0.10% for Rogers) and usually costs 15 to 30 percent less in production volume. Rogers wins on fabricator stocking and prototype lead time — almost every RF board shop has RO4350B in inventory. For outdoor or humid applications, Taconic has the edge. For quick-turn prototypes, Rogers is usually easier to source.

What is the difference between TLY-5 and RF-35 Taconic PCB material?

TLY-5 is pure PTFE with woven glass reinforcement, giving a low Dk of 2.20 and the lowest available Df (0.0009). It is the go-to choice for mmWave work from 24 GHz up to 100 GHz. RF-35 is ceramic-filled PTFE with woven glass, giving a higher Dk of 3.50 and slightly higher Df of 0.0018. RF-35 trades a bit of RF performance for much easier processing (closer to FR-4), better dimensional stability, and a higher Dk that produces narrower traces for a given impedance. For 5G sub-6 GHz base stations and general microwave work, RF-35 is the volume choice; for 77 GHz radar and satellite, TLY-5 takes over.

Can Taconic PCB materials be used in hybrid stack-ups with FR-4?

Yes, and hybrid stacks are actually the most common way Taconic gets used in cost-sensitive production. A typical build places one or two Taconic layers on the outside (carrying the RF circuitry), with FR-4 core and prepreg for the inner digital and power layers. The RF signals never interact with the FR-4 because they are referenced to the ground plane on the Taconic layer. This approach can cut the laminate cost by 50 to 70 percent versus an all-Taconic build while preserving RF performance. Your fabricator needs experience with the CTE and cure profile matching to avoid delamination.

Why is Taconic PCB more expensive than FR-4?

Three reasons compound. First, the raw laminate cost is 4 to 7 times higher than FR-4 because PTFE is a more expensive base resin than epoxy. Second, Taconic boards require specialized fabrication steps — sodium-naphthalene etching for PTFE activation before plating, high-temperature lamination cycles, and slower drilling with faster bit wear. Third, many shops charge setup and handling premiums for PTFE work because it demands dedicated process chemistry and cleanroom handling. On prototype quantities the delta is often 5 to 10 times FR-4 pricing; at production volume it comes down to about 3 times, still significant but manageable.

What frequency range are Taconic PCB materials suitable for?

Taconic materials cover roughly 500 MHz to 100 GHz, with different grades optimized for different bands. RF-35 and HF-series materials are typically used from 1 to 20 GHz. TLY-5 and TLY-3 extend that to 40 GHz comfortably and up to 77 GHz for automotive radar. TLY-5A and TSM-XT are specified up to about 100 GHz for ultra-high-frequency applications like E-band radar and millimeter-wave test equipment. Below 1 GHz, Taconic is usually over-spec’d — FR-4 or high-Tg FR-4 works fine and costs a fraction. The crossover where Taconic starts making sense is generally 3 to 5 GHz, depending on trace length and loss budget.

Final Thoughts

Taconic PCB materials sit in a specific place in the RF laminate market: slightly less visible than Rogers, priced to win on volume, and technically excellent in a couple of areas where nobody matches them — moisture resistance and Df stability over time. For engineers designing for outdoor deployment, automotive environments, or long-lifecycle aerospace systems, the boring but critical properties of PTFE (it does not care about humidity, it does not drift with temperature, it survives thermal cycling) are worth the processing complexity.

The honest working rule I have settled on: if the application lives in a climate-controlled indoor rack and ships in low volumes, Rogers is usually the path of least resistance. If the board goes outside, sees temperature extremes, or ships in tens of thousands of units per year where the laminate cost becomes a real line item, take a hard look at Taconic. The 20 to 30 percent cost saving at volume is real, the electrical performance matches Rogers in every band I have measured, and the moisture immunity is a problem you will not have to debug later.

Talk to your fabricator before finalizing your stack-up. Not every shop is set up for PTFE work, and the ones that are will have preferred part numbers based on what they have process-qualified. Specifying a Taconic material your fabricator cannot run cleanly is a faster way to a respin than picking the “wrong” material family in the first place. The laminate catalog matters less than whether the board actually gets built correctly — and both of those depend on the conversation you have with your manufacturer before the order goes in.