Material Overview
Panasonic MEGTRON6 R-5775 is a high-speed, low-loss multilayer laminate designed for next-generation RF and high-frequency digital applications. With a dielectric constant (Dk) of approximately 3.5 and a dissipation factor (Df) of 0.004 at 1 GHz, R-5775 offers a balance of signal integrity and thermal reliability that makes it a preferred substrate for 5G base station transceivers, millimeter-wave radar, high-speed network switches, and advanced driver-assistance system (ADAS) processing boards. Superb Automation fabricates PCBs on R-5775 and comparable high-frequency laminates from customer Gerber and stackup files. Material is procured per the customer's specification — the laminate choice drives the fabrication process parameters, not the other way around.
R-5775 Material Properties
| Dielectric Constant (Dk) | ~3.5 at 1 GHz — stable across frequency and temperature |
| Dissipation Factor (Df) | ~0.004 at 1 GHz — low signal loss for high-frequency traces |
| Glass Transition (Tg) | ~185°C — suitable for lead-free reflow and high-temperature operation |
| Decomposition Temperature (Td) | >360°C — high thermal stability during assembly and rework |
| CTE (Z-axis) | Low expansion — reduces via barrel stress under thermal cycling |
| Copper Foil | Low-profile (RTF or HVLP) — minimizes conductor loss at high frequencies |
| Available Constructions | Core and prepreg in multiple thicknesses — specified by customer stackup |
Fabrication on R-5775 — Process Adjustments
High-frequency laminates like R-5775 have different mechanical and thermal properties than standard FR-4. Fabrication process parameters are adjusted accordingly:
Drilling
Reduced feed rate and spindle speed: High-Tg, low-CTE laminates are harder than standard FR-4. Drill parameters — RPM, infeed rate, and retract rate — are reduced to prevent resin smear, hole-wall roughness, and drill bit wear. Dedicated tooling sets are maintained for high-frequency laminate jobs to preserve drill bit geometry.
Plasma desmear: After drilling, plasma treatment removes resin smear from inner-layer copper surfaces inside via barrels. The desmear duration is extended for R-5775 compared to standard FR-4 to ensure complete smear removal in high-aspect-ratio vias.
Via reliability verification: First-article boards receive AXI cross-section inspection of via barrels to confirm complete smear removal and uniform copper plating — critical for high-layer-count R-5775 builds where signal vias carry multi-gigabit data.
Lamination
Press cycle optimization: R-5775 prepreg has a different resin flow and cure profile than standard FR-4 prepreg. The lamination press cycle — temperature ramp rate, peak temperature, pressure, and dwell time — is profiled per the laminate manufacturer's recommendations and verified on a test panel before production.
Dimensional stability: Low-CTE laminates are dimensionally stable during lamination, which improves layer-to-layer registration. Post-lamination X-ray measurement confirms registration within ±0.05 mm.
Imaging and Etching
Low-profile copper handling: R-5775 typically uses reverse-treated or HVLP copper foil with lower surface roughness than standard electrodeposited copper. The reduced roughness improves high-frequency signal integrity but requires adjusted photoresist adhesion parameters. LDI imaging parameters — exposure energy and focus — are tuned for low-profile copper surfaces.
Impedance control: Trace width is calculated in CAM from the customer's specified stackup, target impedance, and R-5775's Dk value. Post-etch trace width is measured and compared to the impedance model. TDR coupon measurement on every panel confirms impedance is within the customer's tolerance — typically ±10% for differential pairs.
R-5775 vs. FR-4 — When to Specify High-Frequency Laminate
| Parameter | Standard FR-4 (Tg 130–140°C) | Panasonic R-5775 |
| Dk @ 1 GHz | 4.2–4.8 (varies with resin content) | ~3.5 (stable) |
| Df @ 1 GHz | 0.015–0.025 | ~0.004 |
| Signal loss at 10 GHz | High — unsuitable for multi-gigabit differential pairs | Low — designed for 10 Gbps+ serial links |
| Tg | 130–140°C | ~185°C |
| Typical use | Digital control, low-speed, general purpose | 5G RF, mmWave radar, 25G+ network, ADAS processing |
| Cost multiple vs. FR-4 | 1× | 3–5× — justified by signal integrity requirements |
R-5775 is specified when signal loss, impedance stability, or thermal reliability at high layer counts exceeds what FR-4 can deliver. The decision is the designer's — Superb Automation fabricates to the customer's material specification.
Supported High-Frequency Materials
In addition to Panasonic MEGTRON6 R-5775, Superb Automation fabricates PCBs on:
Panasonic MEGTRON series: R-5775 (M6), R-5670 (M4), and earlier variants — per customer specification
Rogers: RO4000, RO3000, RT/duroid series — for RF and microwave applications
Isola: I-Tera MT40, Astra MT77, and other low-loss grades
Hybrid constructions: High-frequency laminate on RF layers with FR-4 on digital/power layers — per customer stackup
Request Quote — High-Frequency PCB on R-5775, Build-to-Print from Your Gerber + Stackup, TDR-Verified Impedance Control
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