PCB Materials
Megtron 6, 7 & 8 Laminates
Low-loss laminates for 25G to 112G PAM4 high-speed digital designs.
Panasonic Megtron laminates are the standard choice for high-speed digital PCB designs where signal integrity depends on low dielectric loss. The Megtron family spans three generations — Megtron 6, Megtron 7 and Megtron 8 — each offering progressively lower dissipation factor (Df) to support higher data rates and longer trace lengths without excessive signal attenuation. AstroPCB fabricates multilayer boards on all three Megtron grades with controlled impedance and sequential lamination capability.
Megtron 6
Megtron 6 (R-5775N series) is the entry point of the Megtron family for high-speed applications. Its dissipation factor of approximately 0.004 at 1 GHz is roughly half that of standard FR-4 (Df ~0.02), making it suitable for 10 Gbps to 28 Gbps SerDes channels at moderate trace lengths. The dielectric constant is approximately 3.4 at 1 GHz, providing favorable impedance geometries that allow wider traces (lower resistive loss) compared to higher-Dk FR-4 alternatives.
Megtron 6 is the workhorse laminate for enterprise networking switches, storage controllers, server backplanes and telecommunications equipment operating at 10G/25G NRZ signaling. It provides a meaningful performance improvement over Isola 370HR or Shengyi S1000-2M while maintaining compatibility with standard FR-4 fabrication processes — no special drill parameters, plating chemistry or lamination modifications are required.
Megtron 7
Megtron 7 (R-5785N series) reduces the dissipation factor to approximately 0.002 at 1 GHz — half that of Megtron 6 and one-tenth of standard FR-4. This level of performance supports 56 Gbps PAM4 signaling over practical trace lengths in data center switching, AI accelerator interconnects and high-performance computing backplanes. The dielectric constant is approximately 3.3 at 1 GHz.
Megtron 7 occupies the performance tier where the laminate choice directly determines whether a channel passes or fails compliance testing. At 56 Gbps PAM4, a few additional dB of insertion loss can push a channel below the receiver sensitivity threshold. The difference between Megtron 6 and Megtron 7 at 28 GHz (the Nyquist frequency for 56G PAM4) is measurable and often decisive in link budget analysis.
Megtron 8
Megtron 8 (R-5795N series) pushes dissipation factor below 0.002 at 1 GHz, targeting 112 Gbps PAM4 and emerging 224 Gbps signaling standards. It represents the current state of the art in halogen-free glass-reinforced laminates for digital applications. Megtron 8 is specified for next-generation AI training cluster interconnects, 800G Ethernet switches and co-packaged optics substrates where every fraction of a dB matters in the channel loss budget.
Selecting the right Megtron grade
The choice between Megtron 6, 7 and 8 depends on data rate, trace length and loss budget. For 10G/25G NRZ designs with short to moderate trace lengths, Megtron 6 provides adequate margin at the lowest cost. For 56G PAM4 designs, Megtron 7 is the standard recommendation — use Megtron 6 only if link budget simulation confirms sufficient margin. For 112G PAM4 and above, Megtron 8 is the baseline requirement.
Cost scales with performance: Megtron 8 is approximately 2-3x the material cost of Megtron 6, and Megtron 7 falls between them. AstroPCB’s engineering team can run insertion loss estimates during the stackup planning phase to help you select the minimum-cost Megtron grade that meets your channel performance requirement.
Fabrication considerations
All three Megtron grades are compatible with standard multilayer PCB fabrication processes. However, low-loss laminates are more sensitive to copper roughness than standard FR-4. The surface roughness of the copper foil directly adds to insertion loss at high frequencies — a rough copper foil can add 1-2 dB/inch of additional loss at 28 GHz compared to smooth foil. AstroPCB specifies appropriate copper foil grades (HVLP or reverse-treated foil) when fabricating Megtron boards to ensure that the laminate’s low-loss advantage is not negated by copper roughness.
Controlled impedance to ±8% is standard on all Megtron builds. Sequential lamination for HDI constructions is supported. Hybrid stackups combining Megtron signal layers with lower-cost FR-4 power and ground planes are available for designs where the signal layers need low loss but the non-signal layers do not.
Request a Megtron PCB quote
Specify your target data rate, trace length requirements and preferred Megtron grade (or ask the engineering team to recommend based on your channel requirements). Upload your design files and the team will build a stackup, confirm material availability and return a quotation.