PCB Materials
PCB Materials In the table below is a comprehensive list of Sunstone's key printed circuit board manufacturing capabilities.
PCB Materials In the table below is a comprehensive list of Sunstone's key printed circuit board manufacturing capabilities.
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Beyond standard FR-4, Sunstone now offers access to a broader portfolio of advanced laminates for designs where signal speed, thermal reliability, or operating environment push past what conventional materials can handle.
All five of the materials on this page share an important fabrication characteristic: like Isola 370HR, they are all compatible with permanganate desmear processes. This means they can be integrated into existing high-reliability via and plated through-hole workflows without requiring a separate process chemistry.
This page introduces each material, what it's designed for, and when to choose it. If you're not sure which material fits your design, our engineering team is available to work through it with you before you commit to a stack-up.
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Tachyon 100G is lsola's ultra-low loss laminate engineered for the most demanding high-speed digital - backplanes, line cards, and daughter cards operating at 100 Gb/s and beyond. It uses spread glass to reduce skew and HVLP copper (as fine as 2UM RZ) to minimize conductor loss at high frequencies. The material's very low Z-axis CTE makes it a strong choice for high-layer-count boards with fine-pitch BGAs (0.8 mm or below) an d multiple 2 oz. copper planes, where thermal cycling reliability is a primary concern. Electrical properties remain stable across -55°to + 125°C up to 100 GHz
215°C
360°C
3.02 @ 10 GHz
0.0021 @ 10 GHz
2.5% (50-260°C)
6x at 260°C
Best for: 100G+ backplanes, high-layer-count server and networking line cards, fine-pitch BGA designs at 0.8 mm pitch or below, switch fabric borads
FR408HR sits between standard high-Tg FR-4 and premium ultra-low-loss materials. It offers 25% more electrical bandwidth than comparable materials in its class, along with a 30% improvement in Z-axis CTE expansion — the “HR” stands for high reliability and reflects a genuine improvement in thermal-mechanical performance. It’s the material that most commonly appears on approved materials lists for aerospace, defense avionics, and industrial computing programs where moderate signal speeds (1–10 Gbps) and long-term thermal cycling reliability both matter. Processing is closer to conventional FR-4 than any other high-speed material in its class, which helps with fabrication cost and yield.
190°C
360°C
3.68 @ 2 GHz
0.0092 @ 2 GHz
60 min.
6x at 260°C and 288°C
Best for: Aerospace and defense avionics, radar signal processing, telecom infrastructure, industrial computing, medical electronics, IPC Class 3 programs at 1-10 Gbps
The Megtron series from Panasonic is the benchmark for ultra-low-loss, high-speed digital laminate in the networking and data center space. Megtron 6 (Dk 3.7, Df 0.002 @ 1 GHz) handles designs up to roughly 25–28 Gbps with excellent performance. Megtron 7 pushes further — lower Df (0.0015 @ 1 GHz), lower Dk (3.6), and capable through 50+ Gbps channels — making it the right material when 56 Gbps PAM4 or beyond is the target. Both grades offer exceptional through-hole reliability (documented at 5× better than conventional high-Tg FR-4), outstanding thermal stability (Td 410°C), and are lead-free and RoHS compliant. A key practical advantage: both grades process using standard FR-4 lamination temperatures, pressures, and cure times, which simplifies fabrication and enables hybrid stackups with FR-4 core layers on cost-sensitive nets.
185°C (36)/higher (M7)
410°C
3.7 @ 1 GHz
0.002 @ 1 GHz
0.0015 @ 1 GHz
M6: 28G - M7: 56G+
Best for: High-speed networking equipment, date center switches, 5G infrastructure, HPC backplanes, IC testers, high-frequency measurement system, RF applications
The RO4000 series is the industry-standard hydrocarbon ceramic laminate for commercial RF and microwave applications. It delivers electrical performance close to PTFE-based materials at a fraction of the cost and without the specialized processing that PTFE demands — no sodium etch, no special through-hole treatment, standard FR-4-compatible lamination. The two most common grades are RO4003C (Dk 3.55, Df 0.0027 @ 10 GHz — halogen-free, lowest loss in the family) and RO4350B (Dk 3.66, Df 0.0031 @ 10 GHz — UL 94 V-0 rated, specified for active circuits and power RF). The RO4000 series is also the only Rogers line that supports hybrid multilayer construction with FR-4 prepreg, enabling cost-effective stackups where RF performance is only needed on specific layers.
3.55 @ 10 GHz
0.0027 @ 10 GHz
3.66 @ 10 GHz
0.0031 @ 10 GHz
RO4350B only
Supported
Best for: Antenna systems, radar modules, backhaul radios, telecom base stations, sensors, power amplifiers, and mixed RF/digital multilayer designs where RF performance is needed on select layers only
Arlon 85N is a pure polyimide laminate and prepreg system — no epoxy added or blended — designed for boards that will experience sustained high temperatures either in service or during processing. With a Tg above 250°C and a decomposition temperature above 407°C, it significantly outperforms even high-performance epoxy systems in long-term thermal stability. Its Z-axis CTE of 1.2% (50–260°C) is roughly half that of typical high-performance epoxies, which substantially reduces the risk of plated through-hole failures during lead-free reflow. The toughened, non-MDA chemistry resists drill cracking and is halogen-free and RoHS compliant. Desmear is accomplished with alkaline permanganate or plasma (plasma preferred). Currently offered at Sunstone as a 2-layer option.
>250°C
>407°C
1.2% (50–260°C)
>60 min.
IPC-4101/40 and /41
Yes
Best for: Military and aerospace electronics, aircraft engine instrumentation, under-hood automotive controls, down-hole drilling equipment, burn-in boards, industrial sensors operating at sustained high temperatures
| MATERIAL | LOSS TIER | DK (TYPICAL) | DF (TYPICAL) | TG | PRIMARY USE |
|---|---|---|---|---|---|
| Tachyon 100G | Ultra low | 3.02 | 0.0021 | 215°C | 100G+ digital |
| FR408HR | Mid loss | 3.68 | 0.0092 | 190°C | 1–10G hi-rel |
| Megtron 6 | Ultra low | 3.70 | 0.002 | 185°C | Up to 28 Gbps |
| Megtron 7 | Ultra low | 3.60 | 0.0015 | High | 56 Gbps+ |
| RO4003C | Very low | 3.55 | 0.0027 | ~280°C | RF / microwave |
| RO4350B | Very low | 3.66 | 0.0031 | ~280°C | RF / active circuits |
| Arlon 85N | Standard | ~4.2 | ~0.013 | >250°C | High-temp service |
Dk and Df values are representative; actual values vary by frequency, resin content, and glass style. Always verify against the manufacturer's current datasheet for your specific stack-up configuration.
Desmear is the process of removing resin smear from drilled hole walls before copper plating — it's critical for reliable plated through-holes and vias. Permanganate is the most common desmear chemistry used in FR-4 processing. All five materials on this page are compatible with permanganate desmear, which means they can be processed without switching to a different chemistry line. This matters for fabrication cost, scheduling, and yield — materials that require plasma-only desmear or special treatment add steps and complexity.
These materials compete directly in the ultra-low-loss space. Megtron 6 and 7 have a longer qualification history in networking and data center hardware and process identically to FR-4, making them a natural choice when your fab already works with them. Tachyon 100G offers a slightly higher Tg (215°C vs. 185°C for Megtron 6) and is preferred for very high layer count line cards where Z-axis thermal expansion is a board-level reliability concern. The practical choice often comes down to your fab's qualified materials list, your SI team's characterization data, and regional supply chain. Both are excellent materials — pick the one your fab has the most experience with.
If your channel lengths are short, your data rates are below about 10 Gbps, and your primary drivers are thermal reliability and lead-free compatibility rather than insertion loss, FR408HR is often the smarter choice. It processes closer to conventional FR-4 than any other high-speed material, its Dk and Df are well-characterized, and it has a wide qualified fabricator base — which matters a lot for defense and aerospace programs. Ultra-low-loss materials cost more and sometimes add fabrication complexity. FR408HR gives you a genuine performance step up from standard high-Tg FR-4 without going all the way to premium material pricing.
Yes — and this is one of the RO4000 series' most useful characteristics. It's the only Rogers product line designed for hybrid multilayer construction with FR-4 prepreg. This lets you place RO4000 cores on the signal layers where RF performance matters and use lower-cost FR-4 on layers with only power, ground, or low-speed digital routing. Hybrid stackups require careful attention to CTE matching and lamination profile, but they're a well-established approach for managing cost on mixed RF/digital boards.
Pure polyimide like 85N is the right call when boards will see sustained operating temperatures above what high-Tg FR-4 can handle, or when the assembly process itself involves extended high-temperature exposure. Burn-in boards, under-hood automotive electronics, aircraft engine instrumentation, and down-hole drilling equipment are typical examples. The 1.2% Z-axis CTE (vs. 2.5–4.0% for high-performance epoxies) also makes it a strong choice for any thick or high-layer-count board where via barrel cracking under thermal cycling is a concern, even if sustained high temperature isn't the primary driver.
These materials represent Sunstone's expanded capability offering. If you have a project that requires one of these laminates, reach out to our engineering team before submitting files — we can confirm current availability, discuss stack-up options, and connect you with our material representatives for technical support on drill parameters, press profiles, solder mask adhesion, and via fill specifics for your chosen material.