Multi-layer mixed media panels

1. Core Advantages of Mixed Media PCBs
Performance Customization
Low-loss materials are used for the high-frequency signal layer (e.g., Rogers RO4350B, Dk=3.48, Df=0.0037@10GHz), and low-cost FR-4 is used for the power layer, balancing signal integrity and cost.
Thermal management optimization
Combination of high thermal conductivity materials (e.g., aluminum substrate or ceramic-filled resin) and conventional materials to enhance thermal efficiency (thermal conductivity up to 2~8 W/m-K).
Mechanical Stability
Reduce warpage due to thermal cycling stress by CTE matching materials (e.g. polyimide close to copper foil CTE).
2. Manufacturing process challenges and solutions
Key Process Difficulties
Lamination compatibility
Problem: Difference in curing temperature between different materials (e.g. Rogers material requires 288°C lamination, FR-4 is 180°C).
Solution: Step-by-step lamination – low-temperature cure FR-4 part first, then treat HF layer separately.
Drilling Consistency
Problem: Hard material (ceramic filled) leads to fast wear of the drill bit and deviation of the hole diameter > 50 μm.
Solution: Use diamond-coated drill bits and reduce the feed rate (e.g. 10 μm/rev).
Copper foil bonding
Problem: Poor adhesion of low roughness copper foil (HVLP) to HF material (peel strength < 0.8 N/mm).
Solution: Plasma treatment of the surface or use of copper foils with a micro roughness coating (e.g. RTF copper foils).

6. Typical application scenarios

5G base station RF module
Hybrid Rogers RO4835 (antenna layer) + FR-4 (control circuit) for 24~28GHz millimeter wave low loss transmission.
New energy vehicle electronic control unit
Ceramic-filled substrate (heat dissipation layer) + High Tg FR-4 (driver circuit), withstanding 150°C high temperature environment.
Satellite communication equipment
Polytetrafluoroethylene (PTFE) high-frequency layer + Aluminum substrate to meet space-grade thermal cycling (-180℃~+120℃) requirements.