Patent ID: 6372620
Filing Date: 2002-04-16
Classification: H01L,H05K

Abstract:
A fabrication method of a wiring substrate for mounting a semiconductor element, characterized by comprising the steps of:providing a metal base, the metal base having a surface; forming a resist film on the surface of the metal base, the resist film having a negative pattern with respect to a wiring film to be subsequently formed; forming an etching stop layer on the metal base using the resist film as a mask; after forming the etching stop layer, forming a bump by electrolytic plating on the surface of the etching stop layer using the resist film as a mask; forming the wiring film by electrolytic plating on the bump and on the surface of the metal base using the resist film as a mask; after forming the wiring film, removing an unnecessary portion of the etching stop layer by etching while using the etching stop layer as an etching stop; after removing the unnecessary portion of the metal base, removing an unnecessary portion of the etching stop layer by etching to thereby expose the bump.