Patent ID: 7022276

Claim:
A method for manufacturing a circuit board comprising: a first step of preparing a thermal conductive resin composition comprising 70 to 95 mass % of an inorganic filler and 5 to 30 mass % of a resin composition that comprises a thermosetting resin in an uncured state, a thermoplastic resin, and a latent curing agent; a second step of preparing a circuit board precursor by sandwiching the thermal conductive resin composition between two metal foils and bonding the thermal conductive resin composition and the metal foils together by heating at a temperature lower than a temperature at which the thermosetting resin in the thermal conductive resin composition starts to cure while applying pressure so that the thermal conductive resin composition is solidified irreversibly; a third step of providing holes through the circuit board precursor; and a fourth step of curing the thermosetting resin in the circuit board precursor by applying heat and pressure.