High-Speed & RF Laminates
Fabricate Isola stacks spanning the full performance-cost spectrum - from FR408HR low-loss FR-4 for server and storage boards through I-Speed and I-Tera MT40 for 25-56 Gbps SerDes channels to Astra MT77 microwave substrates (Dk 3.0, Df 0.0017 at 10 GHz) for RF sections. We stock the highest-volume Isola grades and deliver validated stack-ups with per-layer glass style documentation, measured copper roughness data for SI solver correlation, and impedance simulation reports on every controlled-impedance build.
Why Engineers Specify Isola
Isola Group is one of the world's largest laminate manufacturers, offering a portfolio that spans from standard FR-4 (IS400, 370HR) through high-performance low-loss grades (FR408HR, I-Speed, I-Tera MT40) to microwave-capable substrates (Astra MT77). FR408HR - with Dk 3.65 and Df 0.0090 at 10 GHz - has become the default low-loss FR-4 choice for PCIe Gen4/Gen5 host bus adapters, NVMe switch fabrics, and 25G optical transceiver boards where standard 370HR's higher loss budget no longer meets channel compliance margins. I-Tera MT40 (Df 0.0045 at 10 GHz) serves 56G PAM4 applications where engineers need meaningful loss reduction below Megtron 4 without the cost premium of ultra-low-loss materials.
Astra MT77 (Dk 3.0, Df 0.0017 at 10 GHz) bridges the gap between digital high-speed and RF microwave applications - making it an increasingly specified substrate for RF control and digital signal processing layers on the same board. APTPCB stocks FR408HR, I-Speed, I-Tera MT40, and Astra MT77 in common core and prepreg thicknesses. Our CAM team generates stack-up proposals with documented glass fabric styles (1080, 2116, 3313), copper roughness classification (STD, VLP, HVLP), and Polar Si9000e impedance simulations for demanding high-speed PCB channels using Isola's published Dk/Df data for each material.
Material Portfolio
Our factory holds validated processing recipes for every product listed below. Each series has documented drill programs, etch parameters, lamination profiles, and quality acceptance criteria in our production database.
| Series | Base Chemistry | Dk Range | Df (Typ. @ 10 GHz) | Key Characteristics | Primary Applications |
|---|---|---|---|---|---|
| 370HR | Multifunctional epoxy / E-glass | 4.04 | 0.021 | Industry-standard high-Tg FR-4 with excellent thermal reliability and CAF resistance. Tg 180 deg C (DSC), Td 340 deg C. Very low Z-axis CTE provides robust PTH reliability through lead-free reflow and multiple thermal excursions. Widely specified baseline for server, storage, and networking boards. | Server motherboards, storage backplanes, networking switch boards, general high-reliability multilayer PCBs, automotive body electronics |
| FR408HR | High-performance multifunctional resin / E-glass | 3.68 | 0.0092 | Lead-free compatible mid-loss laminate bridging standard FR-4 and low-loss materials. Tg 190 deg C, Td 360 deg C. 30% improvement in Z-axis expansion and 25% more electrical bandwidth than standard FR-4. Spread-glass weave available. Compatible with AOI and UV-blocking solder mask imaging. | PCIe Gen4/Gen5 host bus adapters, NVMe switch boards, 25G optical transceivers, high-layer-count HDI, data center infrastructure |
| I-Speed | Low-loss epoxy / E-glass | 3.64 | 0.0060 | Low-loss laminate for mid-range high-speed digital applications. Tg 180 deg C, Td 360 deg C. Significant improvement in Df over FR408HR while maintaining FR-4 processing compatibility. Available in spread-glass weave styles for fiber-weave skew control. | 25G SerDes networking, server backplanes, high-speed storage interfaces, PCIe Gen4 switch fabrics, data center ToR switches |
| I-Tera MT40 | Very low-loss thermoset / E-glass | 3.45 | 0.0031 | Very low-loss laminate with Dk stable from -55 deg C to +125 deg C up to W-band frequencies. Tg 200 deg C, Td 360 deg C. Multiple Dk options (3.38, 3.45, 3.60, 3.75) for impedance flexibility. All glass is spread weave. No special PTFE-type through-hole treatment required. Thermally compatible with Astra MT77 for hybrid builds. | 56G PAM4 backplanes, high-speed switch ASICs, 100G/400G Ethernet, automotive ADAS digital processing, hybrid RF/digital boards |
| Tachyon 100G | Very low-loss thermoset / E-glass | 3.02 | 0.0021 | Ultra-low-loss laminate for the most demanding high-speed digital channels. Tg 215 deg C, Td 360 deg C. Thermally compatible with I-Tera MT40 and Astra MT77 for hybrid multilayer constructions. Spread-glass weave for skew control. | 112G PAM4 channels, next-gen data center switch fabrics, HPC interconnects, co-packaged optics host boards, 800G Ethernet |
| Astra MT77 | Ultra low-loss RF/MW thermoset / E-glass | 3.00 | 0.0017 | Ultra-low-loss laminate bridging high-speed digital and RF/microwave. Dk stable from -40 deg C to +140 deg C up to W-band. FR-4-compatible processing - no plasma desmear required. Compatible with lead-free assembly. Shorter lamination time and higher dimensional stability than PTFE alternatives. | 77 GHz automotive radar, 5G mmWave antenna panels, RF/digital hybrid boards, satellite communication, point-to-point backhaul |
| IS550H | Low-CTE, thermally robust / E-glass | 4.43 | 0.016 | Very high thermal reliability with low CTE. Tg 200 deg C, Td 400 deg C. Designed for applications requiring extreme thermal cycling endurance. Excellent CAF resistance and moisture resistance at reflow. | EV power electronics, under-hood automotive control modules, industrial power converters, high-reliability military electronics |
FR408HR, I-Speed, I-Tera MT40, and Astra MT77 cores and prepregs in common thicknesses are stocked at APTPCB. 370HR, Tachyon 100G, IS550H, and non-standard constructions are available from Isola authorized distributors within 5-10 working days.
Engineering Reference
Comprehensive material data for the most frequently requested models. All dielectric values measured at 10 GHz using clamped stripline resonator method per IPC-TM-650 2.5.5.5 unless otherwise noted. Data sourced from manufacturer published datasheets.
| Property | 370HR | FR408HR | I-Speed | I-Tera MT40 | Tachyon 100G | Astra MT77 | Test Method |
|---|---|---|---|---|---|---|---|
| Dk @ 10 GHz | 4.04 | 3.68 | 3.64 | 3.45 | 3.02 | 3.00 | IPC-TM-650 2.5.5.5 |
| Df @ 10 GHz | 0.021 | 0.0092 | 0.0060 | 0.0031 | 0.0021 | 0.0017 | IPC-TM-650 2.5.5.5 |
| Tg (deg C, DSC) | 180 | 190 | 180 | 200 | 215 | 200 | IPC-TM-650 2.4.25 |
| Td (deg C, TGA 5%) | 340 | 360 | 360 | 360 | 360 | 360 | IPC-TM-650 2.4.24.6 |
| CTE Z (ppm/°C, below Tg) | 45 | 35 | 40 | 38 | 40 | 40 | IPC-TM-650 2.4.41 |
| Moisture Absorption (%) | 0.15 | 0.10 | 0.10 | 0.10 | 0.08 | 0.06 | IPC-TM-650 2.6.2.1 |
| Flammability (UL 94) | V-0 | V-0 | V-0 | V-0 | V-0 | V-0 | UL 94 |
| Plasma Required | No | No | No | No | No | No | - |
| Lead-Free Compatible | Yes | Yes | Yes | Yes | Yes | Yes | - |
| Spread Glass Available | Standard | Yes (all) | Yes | Yes (all) | Yes | Yes | - |
| Common Glass Styles | 1080, 2116, 7628 | 1080, 2116, 3313 | 1035, 1078, 2116 | 1035, 1067, 1086, 2116, 3313 | 1035, 1067, 2116 | 1035, 1067, 2116 | - |
Data from Isola Group published datasheets. All Dk/Df values are at 10 GHz per IPC-TM-650 2.5.5.5 (clamped stripline resonator). All Isola laminates listed process with standard FR-4 chemistry - no plasma desmear required.
Astra MT77 vs. RO4350B
For commercial RF and automotive radar, engineers often compare Astra MT77 with the industry-standard RO4350B. Both process with standard FR-4 chemistry, but Astra MT77 offers distinct advantages in insertion loss for teams evaluating Rogers-style RF laminates.
| Property | Isola Astra MT77 | Rogers RO4350B | Comparison & Impact |
|---|---|---|---|
| Dk @ 10 GHz | 3.00 | 3.48 +/-0.05 | Astra's lower Dk supports wider traces for the same impedance, reducing skin-effect loss. |
| Df @ 10 GHz | 0.0017 | 0.0037 | Astra has 54% lower Df, significantly improving signal integrity at mmWave frequencies (e.g., 77 GHz radar). |
| Resin System | Thermoset / E-glass | Hydrocarbon Ceramic | Both are non-PTFE and process easily without plasma desmear. |
| Tg (Glass Transition) | 200 deg C | >280 deg C | RO4350B has a higher Tg, though 200 deg C is highly robust for lead-free assembly. |
| Hybrid Compatibility | Excellent (with I-Tera MT40) | Excellent (with FR-4) | Isola specifically designs Astra to co-laminate seamlessly with its digital high-speed materials. |
While RO4350B is a legacy benchmark below 10 GHz, Astra MT77's ultra-low loss profile makes it a superior, cost-effective choice for modern 5G mmWave and 77 GHz automotive radar applications.
Manufacturing Process
Processing Isola materials requires equipment, chemistry, and process knowledge that go beyond standard FR-4 manufacturing. Our factory addresses every critical fabrication step with purpose-built equipment and validated recipes developed through years of production experience with these specific substrate materials.
Every production lot follows documented procedures with real-time parameter monitoring. Process data including drill speeds, etch chemistry concentrations, lamination temperatures, plating bath composition, and inspection results are archived per lot number for full traceability and continuous improvement analysis.
Our CAM engineering team reviews every incoming design for manufacturability before production begins, providing DFM feedback, impedance simulation data (Polar Si9000 with manufacturer Dk/Df curves), stack-up optimization recommendations, and material selection guidance at no additional charge. This front-end investment reduces production risk and ensures boards are built right the first time.
Reference Stack-Ups
Representative configurations with validated press profiles and established supply chains. Custom configurations welcome — contact our engineering team with your specific requirements.
| Configuration | Layers | Signal Cores | Structural | Bonding System | Applications |
|---|---|---|---|---|---|
| Astra MT77 RF | 2-4 | Astra MT77 all layers | - | Astra MT77 prepreg | Satellite LNA, calibration substrates, MIL-spec stripline networks |
| I-Tera MT40 / Astra MT77 Hybrid | 4-8 | Astra MT77 (RF) + I-Tera MT40 (digital) | 370HR | I-Tera MT40 prepreg | RF/digital hybrid boards, automotive radar with digital processing |
| Tachyon 100G High-Speed | 4-16 | Tachyon 100G all signal layers | I-Tera MT40 | Tachyon 100G prepreg | 112G/224G PAM4 backplanes, 800G/1.6T Ethernet switch boards |
| I-Tera MT40 + 370HR Hybrid | 4-20 | I-Tera MT40 (signal) | 370HR (pwr/gnd) | I-Tera MT40 prepreg | 56G PAM4 SerDes, server backplanes, networking switch boards |
| FR408HR Standard | 4-12 | FR408HR all layers | - | FR408HR prepreg | PCIe Gen4/Gen5, NVMe, 25G optical transceivers, general high-speed |
| I-Speed Mid-Range | 4-12 | I-Speed all layers | - | I-Speed prepreg | 10–25 Gbps networking, server backplanes, storage interfaces |
| Astra MT77 + Tachyon Hybrid | 4-12 | Astra MT77 (RF) + Tachyon 100G (digital) | I-Tera MT40 | I-Tera MT40 prepreg | 5G mmWave with high-speed digital processing, automotive radar + digital |
| 370HR / IS550H Thermal | 4-12 | 370HR or IS550H | - | 370HR / IS550H prepreg | High-reliability automotive, industrial power, EV power electronics |
Fabrication Capabilities
Six core capabilities that differentiate our Isola production from general-purpose PCB manufacturing for high-speed PCB and RF builds.
Isola laminates are thermoset resin-based and process with standard FR-4 chemistry - no plasma desmear, no special surface activation, and no modified drill programs required. This is a key processing advantage over PTFE-based alternatives from Rogers and Taconic. Standard permanganate desmear effectively removes drilling smear on all Isola grades.
Isola thermoset laminates use standard drill programs compatible with FR-4 equipment - no reduced speeds or special PTFE handling required. For boards with via aspect ratios exceeding 8:1, we perform microsection analysis on pilot holes to verify hole wall quality and smear removal effectiveness before proceeding with production drilling.
Our wet-etch process holds trace line-width tolerance within +/-0.5 mil on Isola substrates, preserving 50 ohm single-ended and 100 ohm differential impedance targets with better than +/-7% total tolerance. Every controlled-impedance Isola build includes TDR-measured coupons with measured impedance values documented against simulation targets.
Different Isola grades can be combined in a single stack-up - for example, Astra MT77 RF layers with I-Tera MT40 high-speed digital layers, or Tachyon 100G signal layers with 370HR structural cores. Our CAM engineers model impedance at every dielectric boundary, select appropriate prepreg grades for each interface, and validate the lamination cycle before volume production begins.
All Isola laminates are stored in our climate-controlled warehouse and undergo documented pre-lamination bake cycles per Isola's handling guidelines when required. Incoming material is stored below 45% relative humidity at 22 +/-2 deg C. Bake completion timestamps, oven logs, and lot IDs are recorded in each production traveler.
Surface finish selection directly impacts high-frequency insertion loss, passive intermodulation, and solder joint reliability on Isola substrates. Our typical recommendations are immersion silver for the lowest surface resistivity on RF traces, ENIG for fine-pitch assembly, and ENEPIG for antenna boards subject to PIM qualification.
Quality & Validation
Our quality management system operates under ISO 9001:2015 certification with IPC-6012 acceptance criteria (Class 2 standard, Class 3 for high-reliability) applied to every production lot. In-process inspection includes AOI at inner layer, outer layer, and solder mask stages; electrical continuity and isolation testing via flying probe or fixture; and dimensional verification against customer specifications under the same disciplined PCB quality workflow used across our factory.
For controlled-impedance builds, TDR-measured impedance coupons are included on every production panel with measurement data recorded against simulation targets. Extended validation options include VNA S-parameter sweeps on dedicated test vehicles, cross-section micrograph analysis with dimensional annotations, IST reliability testing per IPC-TM-650 2.6.26, ionic cleanliness testing, and full IPC-6012 Class 3 documentation packages with serialized board traceability.
For automotive programs, we follow IATF 16949 quality practices. For aerospace and defense programs, extended documentation packages including environmental test reports (thermal shock, moisture resistance, vibration), microsection micrographs, and serialized traceability from raw material lot through final shipping inspection are available per customer specification.
Industry Applications
Isola substrates serve the most demanding applications across telecommunications, automotive, aerospace, defense, data center, medical, and industrial markets.
5G base station infrastructure including massive MIMO antenna control boards, beamforming digital processing modules, and baseband units. I-Tera MT40 and Astra MT77 serve both digital processing and RF sections in hybrid 5G boards.
Satellite communication digital processing boards, LEO gateway modems, and ground station baseband units. I-Tera MT40 serves high-speed digital channels, while Astra MT77 provides ultra-low-loss RF performance for hybrid satellite boards.
Defense digital processing and computing boards, radar signal processing units, secure communication systems, and military networking equipment. Isola laminates support high-reliability digital and mixed-signal applications in defense platforms.
Automotive radar sensor front ends for ACC, AEB, blind-spot detection, lane-change assist, and cross-traffic alert systems. Astra MT77 provides ultra-low-loss performance for 77 GHz radar front ends with FR-4-compatible processing, while I-Tera MT40 serves digital processing layers.
Test equipment including high-speed oscilloscope probe boards, signal analyzer input stages, and ATE load boards. Isola laminates provide the controlled impedance and low-loss performance needed for accurate signal acquisition at multi-GHz frequencies.
Data center networking, cloud computing, and AI/HPC infrastructure boards. I-Tera MT40 and Tachyon 100G support the 56G/112G PAM4 channels in high-speed switch ASICs and co-packaged optics host boards.
Material Selection Guide
The optimal Isola laminate depends on three primary factors: data rate, operating frequency, and cost sensitivity. Here is a practical selection framework based on our manufacturing experience across thousands of Isola builds.
For general high-reliability multilayer applications - servers, storage, networking, and industrial electronics - 370HR is the industry-standard baseline with Tg 180 deg C and strong thermal cycling endurance. When insertion loss becomes a concern, step up to FR408HR (Df 0.0092 at 10 GHz) for meaningfully lower loss with the same processing compatibility.
For high-speed digital applications from 10 Gbps to 56 Gbps - including PCIe Gen4/Gen5, 100G Ethernet, NVMe, and 56G PAM4 SerDes channels - I-Speed handles 10-25 Gbps economically, while I-Tera MT40 serves 25-56 Gbps with multiple Dk options for impedance flexibility. Both process with standard FR-4 chemistry and are available in spread-glass weave constructions for skew control. Teams planning mixed RF/digital builds often review this alongside our Rogers laminate guidance.
For the most demanding high-speed digital channels, Tachyon 100G provides Isola's lowest insertion loss in a thermoset material. For RF and microwave applications including 77 GHz automotive radar and 5G mmWave, Astra MT77 delivers ultra-low-loss performance with FR-4-compatible processing - a cost-effective alternative to PTFE substrates that eliminates the need for plasma desmear and special drilling, while Megtron-class ultra-low-loss materials remain the stronger fit for pure digital backplanes.
For applications demanding extreme thermal cycling endurance - EV power electronics, under-hood automotive control modules, and high-reliability industrial systems - IS550H provides the highest thermal reliability in Isola's portfolio with low CTE and strong CAF resistance.
For many commercial RF and automotive radar designs, Astra MT77 (Dk 3.00, Df 0.0017 at 10 GHz) provides ultra-low-loss performance comparable to PTFE substrates while maintaining FR-4-compatible processing. This significantly reduces both manufacturing cost and lead time compared to PTFE alternatives.
FAQ
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Global Engineering Reach
Server OEMs, storage system designers, and RF engineers worldwide rely on APTPCB for custom PCB fabrication using Isola high-speed and microwave laminates. Online quoting, DFM review, and worldwide shipping.
Defense contractors, telecom OEMs, and hardware startups across the US and Canada rely on APTPCB for prototype and NPI builds. Same-day DFM review. ITAR-aware documentation is available on request.
Automotive radar suppliers in Germany, defense electronics teams in the UK and France, and Scandinavian wireless R&D labs source prototypes and production-intent boards through our platform.
5G base station manufacturers, satellite terminal developers, and hardware startups across APAC use our online quoting platform for prototypes and NPI runs with 24-hour DFM response.
Aerospace radar, defense EW, and SATCOM programs in the region rely on our extended qualification documentation packages and material traceability for defense procurement compliance.
Share your Gerber files, material requirements, impedance targets, and performance specifications. Our engineering team will return a validated stack-up proposal, DFM review, and detailed quotation within one business day.
