US Patent 7626124 Wiring board

A wiring board has a circuit pattern that includes metal foil attached to an insulating layer, and a built-up circuit pattern disposed on top of the metal foil circuit pattern. The built-up circuit pattern is an increased thickness laminate of cold spray processed metal material. Even when a power semiconductor is mounted on the built-up circuit pattern, the heat that is generated by losses therein can be diffused by the built-up circuit pattern. The wiring board has excellent heat dissipation, can be manufactured by a small number of process steps, and is of low cost.