High-Speed Digital Materials
APTPCB is a Megtron PCB manufacturer for controlled-impedance 56G and 112G PAM4 SerDes channels. We engineer spread-glass stackups, VLP/HVLP copper, TDR/VNA and COM/eye analysis, with backplanes up to 40+ layers.
Why Engineers Specify Megtron
APTPCB manufactures high-speed digital boards using Panasonic's Megtron family for SerDes backplanes and channel designs. Megtron 4 (Df ~0.005 at 1 GHz) is a low-loss FR-4 alternative for PCIe Gen3/Gen4 and 10-25 Gbps applications. Megtron 6 (Df ~0.002) supports 56G PAM4 backplanes and data-center switch ASICs. Megtron 7 (Df ~0.0015 with improved Z-axis CTE) targets high-layer-count backplanes where microvia reliability and signal integrity must be reviewed together. Megtron U and Megtron 8 address 112G/224G PAM4 design studies.
Our engineering team prepares spread-glass options (1035, 1067, 2116), VLP/HVLP copper choices, layer-by-layer dielectric proposals, copper roughness inputs for Causal RLGC modeling, and Polar Si9000e impedance simulations for high-speed PCB channels. Sequential lamination and buried/blind microvia routes can support 40+ layer backplanes; final construction and acceptance criteria are confirmed during stack-up and RFQ review.
Material Portfolio
Compare the Megtron grades commonly considered for high-speed digital boards; final material and glass choices depend on channel, stack-up and RFQ review.
| Series | Base Chemistry | Dk Range | Df (Typ. @ 10 GHz) | Key Characteristics | Primary Applications |
|---|---|---|---|---|---|
| Megtron 4 (R-5725 / R-5620) | Modified PPE resin / E-glass | 3.8 | 0.005 | Low-loss FR-4 alternative. Tg 176 deg C, Td 360 deg C. Processes with standard FR-4 equipment and chemistry. Lead-free process options can be reviewed in the RFQ. Good balance of electrical performance and cost for mid-speed digital applications. | PCIe Gen3/Gen4, 10–25 Gbps SerDes, network routers, server boards, measuring instruments |
| Megtron 6 (R-5775 / R-5670) | PPE resin / E-glass (standard and low-Dk glass) | 3.4 (N-glass) / 3.7 (E-glass) | 0.002 | Ultra-low-loss, industry benchmark for high-speed digital. Tg 185 deg C, Td 410 deg C. Available with standard E-glass or low-Dk N-glass. Excellent HDI and thermal performance. FR-4-compatible processing. Spread-glass weave options for skew control. | 56G PAM4 backplanes, data center switches, 400G Ethernet, AI/HPC interconnects, high-speed IC testers |
| Megtron 7 (R-5785 / R-5680) | Advanced PPE resin / E-glass (standard and low-Dk glass) | 3.3 (N-glass) / 3.6 (E-glass) | 0.0015 | Next-generation ultra-low-loss with improved Z-axis CTE for high-layer-count reliability. Tg 200 deg C, Td 400 deg C. May support longer channel designs than Megtron 6 when the complete stack-up and loss budget allow. IST microvia testing can be scoped for high-layer-count backplanes. | 112G PAM4 backplanes, 800G Ethernet switches, HPC/AI server interconnects, next-gen switch ASIC host boards |
| Megtron 8 (R-5795 / R-5690) | Next-gen ultra-low-loss resin / E-glass | 3.1 | 0.0012 | Panasonic's latest ultra-low-loss grade for the most demanding next-generation channels. Tg 220 deg C, Td 370 deg C. Designed for 224G PAM4 and beyond. FR-4-compatible processing maintained. | 224G PAM4, next-gen co-packaged optics, 1.6T Ethernet, advanced AI accelerator interconnects |
| R-1755V | High-Tg FR-4 epoxy / E-glass | 4.4 | 0.016 | Standard high-Tg FR-4 baseline from Panasonic. Tg 173 deg C, Td 350 deg C. Cost-effective option for non-critical signal layers in hybrid stack-ups or applications where electrical loss is not the primary concern. | Power/ground layers in hybrid stacks, general multilayer PCBs, non-critical digital, cost-sensitive applications |
Megtron 4, Megtron 6 (R-5775/R-5670), and Megtron 7 (R-5785/R-5680) cores and prepregs can be specified with common thicknesses, glass styles (1035, 1067, 1078, 2116), and VLP/HVLP copper options subject to RFQ confirmation. Megtron 8 and non-standard constructions require material-availability review.
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 | Megtron 4 | Megtron 6 (E-glass) | Megtron 6 (N-glass) | Megtron 7 (E-glass) | Megtron 7 (N-glass) | Megtron 8 | Test Method |
|---|---|---|---|---|---|---|---|
| Dk @ 1 GHz | 3.8 | 3.7 | 3.4 | 3.6 | 3.3 | 3.1 | IPC-TM-650 2.5.5.5 |
| Df @ 1 GHz | 0.005 | 0.002 | 0.002 | 0.0015 | 0.0015 | 0.0012 | IPC-TM-650 2.5.5.5 |
| Tg (deg C, DSC) | 176 | 185 | 185 | 200 | 200 | 220 | IPC-TM-650 2.4.25 |
| Td (deg C, TGA 5%) | 360 | 410 | 410 | 400 | 400 | 370 | IPC-TM-650 2.4.24.6 |
| Flammability (UL 94) | V-0 | V-0 | V-0 | V-0 | V-0 | V-0 | UL 94 |
| Lead-Free Compatible | Yes | Yes | Yes | Yes | Yes | Yes | - |
| Plasma Required | No | No | No | No | No | No | - |
| FR-4 Compatible Processing | Yes | Yes | Yes | Yes | Yes | Yes | - |
| Spread Glass Available | Yes | Yes | Yes (all) | Yes | Yes (all) | Yes | - |
| Common Glass Styles | 1080, 2116, 7628 | 1035, 1078, 2116 | 1035, 1078, 2116 | 1035, 1067, 2116 | 1035, 1067, 2116 | 1035, 1067, 2116 | - |
| Panasonic Part # (Laminate) | R-5725 | R-5775 | R-5775(N) | R-5785 | R-5785(N) | R-5795 | - |
| Panasonic Part # (Prepreg) | R-5620 | R-5670 | R-5670(N) | R-5680 | R-5680(N) | R-5690 | - |
Data from Panasonic Industrial published datasheets. Dk/Df values are at 1 GHz per Panasonic standard test method. Megtron grades generally use standard FR-4 lamination parameters; the final desmear and through-hole route is confirmed for the selected construction.
Megtron 6 vs. I-Tera MT40
For 56G PAM4 high-speed digital designs, engineers frequently evaluate Megtron 6 against Isola I-Tera MT40. Both are ultra-low-loss thermoset materials that process like standard FR-4, but they offer distinct advantages depending on stack-up requirements and the broader Isola laminate family already qualified in the program.
| Property | Megtron 6 (E-glass) | Isola I-Tera MT40 | Comparison & Impact |
|---|---|---|---|
| Dk @ 10 GHz | 3.60 | 3.45 | I-Tera has a slightly lower Dk, allowing for marginally wider traces when targeting 100 ohm differential pairs. |
| Df @ 10 GHz | ~0.004 (@10G) / 0.002 (@1G) | 0.0031 | Both laminates provide highly comparable insertion loss performance perfectly suited for 56G channels. |
| Tg (Glass Transition) | 185 deg C | 200 deg C | I-Tera provides a slightly higher Tg, offering excellent thermal reliability for high-layer-count boards. |
| Processing | Standard FR-4 Chemistry | Standard FR-4 Chemistry | Both completely eliminate the need for costly and time-consuming PTFE plasma desmear. |
| Hybrid RF Use | Primarily Digital Use | Excellent | I-Tera is specifically designed to be thermally compatible with Astra MT77 for RF/digital hybrid boards. |
Megtron 6 and I-Tera MT40 are both candidates for pure digital backplanes; the suitable option depends on the stack-up, loss budget, hybrid RF needs and RFQ review.
Manufacturing Process
Processing Megtron materials requires equipment, chemistry, and process knowledge beyond standard FR-4 manufacturing. Our team reviews the intended material, glass, copper and lamination route before production so the released build matches the approved stack-up.
Production records can include drill, etch, lamination, plating and inspection data tied to the lot or order. The supplied record set is agreed in the RFQ and supports traceability without implying a universal test package.
Our CAM engineering team reviews incoming designs for manufacturability, impedance simulation inputs (Polar Si9000 with manufacturer Dk/Df curves), stack-up optimization recommendations, and material selection guidance before release.
Reference Stack-Ups
Representative configurations for engineering discussion. Final dielectric thickness, glass style, copper roughness, press profile and acceptance limits are confirmed against the released RFQ.
| Configuration | Layers | Signal Cores | Structural | Bonding System | Applications |
|---|---|---|---|---|---|
| Megtron 6 Full Stack | 4-20 | Megtron 6 all signal layers | - | Megtron 6 prepreg | 56G PAM4 backplanes, data center switches, 400G Ethernet |
| Megtron 7 Full Stack | 4-40 | Megtron 7 all signal layers | - | Megtron 7 prepreg | 112G PAM4, 800G Ethernet, HPC/AI interconnects |
| Megtron 6 + Megtron 4 Hybrid | 4-20 | Megtron 6 (signal) | Megtron 4 (pwr/gnd) | Megtron 4 prepreg | Cost-optimized high-speed boards, server backplanes |
| Megtron 6 + FR-4 Hybrid | 4-16 | Megtron 6 (signal) | Standard FR-4 (pwr/gnd) | Standard prepreg | Cost-sensitive networking, general high-speed digital |
| Megtron 7 + N-glass | 4-40 | Megtron 7 (N-glass signal) | Megtron 7 (E-glass structural) | Megtron 7 prepreg | Ultra-low-loss backplanes, next-gen switch ASIC host boards |
| Megtron 8 Ultra-Low-Loss | 4-20 | Megtron 8 all signal layers | - | Megtron 8 prepreg | 224G PAM4, co-packaged optics, 1.6T Ethernet |
| Megtron + I-Tera MT40 Hybrid | 4-16 | Megtron 6 (digital) | I-Tera MT40 (RF layers) | I-Tera MT40 prepreg | RF/digital hybrid boards, automotive radar + digital processing |
| R-1755V Standard | 4-12 | R-1755V all layers | - | R-1755V prepreg | General multilayer, power/ground in hybrid stacks, cost-sensitive digital |
Fabrication Capabilities
Six core capabilities that differentiate our Megtron production from general-purpose PCB manufacturing for high-speed PCB programs.
Megtron laminates are PPE thermoset resin-based and process with standard FR-4 chemistry without plasma desmear, special surface activation, or modified drill programs. All Megtron grades use the same lamination pressures, temperatures, and cure times as conventional FR-4.
Megtron laminates process with standard FR-4 drill parameters - no reduced speeds or special PTFE handling required. For high-layer-count backplanes, we optimize drill programs with controlled chip-load feed rates, appropriate entry/backup materials, and aspect-ratio-specific parameters.
Our wet-etch process is set up against the released trace geometry and impedance targets. Where TDR coupons are ordered, measured values are documented against the approved simulation targets for the build.
Different Megtron grades can be combined within a single stack-up - for example, Megtron 6 signal layers with Megtron 4 or standard FR-4 structural layers. Our CAM engineers model impedance at every dielectric boundary, select prepreg grades for each interface, and validate the lamination cycle with thermocouple-monitored test runs.
Megtron laminates are stored in climate-controlled conditions and undergo documented pre-lamination bake cycles when required. Typical bake parameters are 2-4 hours at 105-120 deg C in calibrated forced-air convection ovens, with exact temperature and duration determined by the specific material model, core thickness, and copper cladding weight.
Surface finish selection directly impacts high-frequency insertion loss, passive intermodulation, and solder joint reliability on Megtron substrates. Typical recommendations are immersion silver for the lowest surface resistivity on RF signal traces, ENIG for assemblies requiring multi-reflow compatibility, and ENEPIG for antenna boards subject to PIM qualification.
Quality & Validation
Megtron SI validation is scoped to the released RFQ and can compare impedance targets with TDR coupon data, insertion-loss sweeps, COM or eye-diagram analysis, and the agreed channel model. Typical electrical values are design inputs, not a finished-channel guarantee.
Where ordered, SI validation outputs can include VNA S-parameter sweeps on dedicated test vehicles, cross-section micrographs with dimensional annotations, and IST reliability testing per IPC-TM-650 2.6.26. Material documentation and inspection records are supplied according to the agreed order package.
Inspection scope, acceptance criteria, traceability depth and environmental or reliability testing are confirmed for the application during RFQ review.
Industry Applications
Megtron 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. Megtron's low-loss characteristics support the high-speed SerDes channels connecting FPGA/ASIC to RF front-end modules.
High-speed digital processing boards for satellite ground terminals and LEO gateway modems. Megtron 6 and Megtron 7 serve the 56G and 112G PAM4 SerDes channels in satellite communication baseband processing units and ground station digital equipment.
Military and defense digital processing boards for radar signal processing, electronic warfare computing, and secure communications. Megtron 6 and 7 support high-speed digital backplanes and signal processing boards in defense systems.
Automotive ADAS digital processing boards, in-vehicle networking, infotainment system host boards, and EV battery management digital controllers. Megtron 6 and Megtron 7 support the high-speed interfaces in autonomous driving compute platforms.
High-speed IC test equipment including ATE load boards, IC tester interface boards, and burn-in boards for semiconductor validation. Megtron 6 is widely specified for IC tester channel boards where signal integrity at 56G+ directly affects test accuracy and throughput.
Data center and cloud computing infrastructure including top-of-rack switches, spine switches, storage controllers, and AI/HPC accelerator host boards. Megtron 6 dominates 400G Ethernet switch boards, while Megtron 7 and 8 target 800G/1.6T next-generation platforms.
Material Selection Guide
Use the following engineering inputs to start a Megtron PCB manufacturer review. Recommendations remain provisional until the stack-up and RFQ are approved.
For PCIe Gen3/Gen4 and 10-25 Gbps SerDes applications, Megtron 4 provides a meaningful reduction in insertion loss versus standard FR-4 at a moderate cost premium. It processes identically to conventional FR-4, making it the logical first step up from standard FR-4 when signal-integrity margins are tight.
Megtron 6 is the industry benchmark for 56G PAM4 backplanes and data center switch ASICs. Available with standard E-glass or low-Dk N-glass cloth, it provides materially lower loss than standard FR-4 on long differential traces. Spread-glass weave options control differential skew.
For 112G PAM4 and beyond, Megtron 7 and Megtron U can be evaluated for longer-reach or high-layer-count designs. Channel length, loss budget, glass choice and Z-axis reliability targets remain design-dependent and require SI review.
For non-critical layers in hybrid Megtron stacks such as power, ground, and low-speed control, Panasonic R-1755V provides a standard high-Tg FR-4 baseline at lower cost. Megtron 4 also serves as a cost-effective structural layer material where premium Megtron 6/7 is reserved for the highest-speed signal layers.
Include the target data rate, maximum channel length, layer count, glass style, copper roughness, impedance targets, and quantity. Also identify the loss budget, surface finish, test coupon needs, SI validation outputs where ordered, material documentation, and inspection records. APTPCB uses these inputs to prepare a stack-up proposal; final material selection and acceptance criteria follow stack-up and RFQ review.
FAQ
Interactive Tool
Use the recommendation as an engineering starting point only. Final Megtron grade, glass style, copper and test scope are confirmed through stack-up and RFQ review.
Global Engineering Reach
Data-center, network-switching and high-speed storage teams use Megtron 6 and Megtron 7 for 56G and 112G PAM4 channel designs. APTPCB reviews stack-up and DFM inputs as part of the RFQ.
Defense contractors, telecom OEMs, and hardware startups across the US and Canada use APTPCB for prototype and NPI builds. Documentation scope is agreed during the RFQ.
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 DFM scope agreed during the RFQ.
Aerospace radar, defense EW, and SATCOM programs in the region rely on our extended qualification documentation packages and material traceability for defense procurement compliance.
Send Gerber files or an early design brief with target data rate, channel length, layer count, glass style, copper roughness, impedance targets and quantity. APTPCB can prepare a stack-up proposal, impedance/TDR data, SI validation outputs where ordered, material documentation and inspection records for the agreed order scope.
