Fabrication process of wiring board

摘要

A wiring board is fabricated through the following steps: (A) forming, on one side of an elongated carrier metal foil made of a first metal, a thin layer with a second metal whose etching conditions are different from those of the first metal; (B) forming, on a surface of the thin layer, a desired wiring pattern with a third metal whose etching conditions are different from those of the second metal; (C) superposing the carrier metal foil on an insulating substrate with the side of the wiring pattern being positioned inside, whereby the wiring pattern is embedded in the insulating substrate; and (D) etching off the carrier metal foil and the thin layer at desired parts thereof.