The copper base board is the most expensive one among the metal substrates, and the heat conduction effect is many times better than that of the aluminum substrate and the iron substrate. It is suitable for high-frequency circuits and regions with high and low temperature variations and the heat dissipation and architectural decoration industries of precision communication equipment.
Generally, the finishing include ENIG, immersion silver, LF HASL, OSP, etc. The copper substrate circuit layer is required to have a large current carrying capacity, so a thick copper foil should be used, and the thickness is generally 35 μm to 280 μm; the thermal conductive insulating layer is the core technology of the copper substrate, and the core thermal conductive component is aluminum oxide and silicon powder. It consists of a polymer filled with epoxy resin, low thermal resistance (0.15), excellent viscoelasticity, resistance to heat aging, and ability to withstand mechanical and thermal stresses.