A ceramic-filled PTFE laminate with Dk near 3.0 and Df near 0.003 — what the parameters mean, where it is specified, and how it is made.
Taconic RF-30 is one of the materials that made the company’s name in RF work: a PTFE-based substrate with ceramic filler, tuned for circuits that operate well above the range where FR-4 stops being a serious option. It is specified for radio and microwave hardware, and the reason is a combination of low loss with a dielectric constant low enough to keep delay and impedance manageable. This article covers the parameters, the applications and what happens during production — for the wider brand picture, see our notes on the performance of Taconic high-frequency laminates and on competing microwave substrate materials.
RF-30 is a ceramic-filled PTFE laminate. The PTFE base supplies the electrical behaviour, and the ceramic filler is what makes the material practical to build with: it raises mechanical stability and thermal performance while keeping loss low. That combination is why the grade appears in communication, radar, aerospace, automotive and medical hardware rather than in one narrow niche — the electrical performance is high enough for microwave work and the physical performance is good enough for volume manufacturing.
Four parameters do most of the work when RF-30 is being specified. Dk sits near 3.00 at 10 GHz and stays stable across frequency, which keeps propagation delay and impedance predictable. Df is around 0.003, low enough to limit attenuation in microwave and RF signal paths. A very low coefficient of thermal expansion holds the dimensions steady when temperature moves, and the operating range of roughly −40°C to +150°C covers most field environments. Thickness is selectable, typically between 0.076 mm and 0.508 mm, so the same material can serve thin, tightly controlled RF layers and thicker structural ones.
| Parameter | Typical value |
|---|---|
| Dielectric constant (Dk) | ≈3.00 at 10 GHz |
| Dissipation factor (Df) | ≈0.003 |
| Coefficient of thermal expansion | Very low; high dimensional stability |
| Operating temperature range | −40°C to +150°C |
| Thickness range | 0.003–0.020 in (0.076–0.508 mm) |
| Base construction | PTFE resin with ceramic filler |
RF-30 turns up anywhere a design needs low loss and stable behaviour at the same time. Six areas account for most of the volume.
Production splits into four stages, and each one has a different effect on the finished laminate.
The base is high-quality PTFE resin, chosen for insulation performance, heat resistance and low dissipation, combined with ceramic fillers that tune the electrical behaviour in the microwave band. Purity at this stage is what makes the finished properties repeatable rather than merely acceptable.
Hot pressing, stretching and precision cutting are controlled closely, because it is the process rather than the formulation that decides whether Dk and Df stay inside tolerance. Advanced composite technology is what allows the ceramic filler to be distributed evenly enough that the microwave performance holds across a panel.
Metallisation and finishing follow the usual routes: surface treatment for high-frequency boards typically lands on ENIG or OSP, chosen for solderability and corrosion resistance. The trade-offs between finishes are worth reviewing before a build, since they affect loss and flatness in different ways; our comparison of ENIG, immersion silver and immersion tin covers the practical differences.
Every batch is tested for electrical, mechanical and thermal properties against specification, and the material is supplied with customisation options for designs that need a specific thickness or panel format. The useful question for a buyer is not whether testing happens but what the acceptance criteria are and how a batch that misses them is handled.
RF-30 fits designs that need a Dk near 3.0 with low loss and a wide operating temperature window — a microwave transceiver, a radar front end, a satellite module. If the design needs the dielectric constant tuned grade by grade, the TLX series covers a wider spread of Dk values. If the emphasis is on thermal headroom instead, the TLY-3 grade runs to a higher temperature. Send us the frequency plan and the stack-up and we will tell you which of the three the numbers actually support.
Frequently Asked Questions
A PTFE resin base with ceramic filler. The PTFE supplies the low-loss electrical behaviour and the ceramic content adds mechanical stability and thermal performance, which is what makes the grade practical in volume production.
Approximately 3.00 at 10 GHz, and it stays stable over frequency. That stability is more useful than the absolute number, because impedance and delay calculations depend on Dk not moving.
Typically 0.003 in to 0.020 in, or 0.076 mm to 0.508 mm. Thin material serves tightly controlled RF layers, thicker material works where mechanical rigidity matters.
It needs adjusted process windows rather than a different line. Drilling parameters, via preparation and lamination cycles are all affected, which is why fabricator experience on PTFE laminates matters more than the material data sheet.
RF-30 sits around Dk 3.0 with a wide temperature range. TLY-3 runs to a higher temperature ceiling, and the TLX series spreads Dk from 3.00 to 3.40 so designers can match a specific impedance target.
Send us your frequency range and stack-up and we will confirm whether RF-30 is the right substrate for the build.
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