Patent ID: 7425683
Filing Date: 2008-09-16
Classification: H01L,H05K

Abstract:
1. A flexible wiring substrate comprising an insulating substrate, a wiring pattern formed on a surface of the insulating substrate, and a solder resist layer formed on a surface of the wiring pattern, wherein the solder resist layer is formed on a part of the surface of the wiring pattern to leave at least terminal portions of the wiring pattern uncovered by the solder resist layer, wherein the uncovered terminal portions of the wiring pattern have a tin-bismuth alloy plating layer which is formed on the surface of the wiring pattern, and wherein the wiring pattern is a multilayer comprising a base layer formed of a conductor and a first tin plating layer, and a second tin plating layer is disposed between the first tin plating layer and the tin-bismuth alloy plating, layer, and formed adjacent to the solder resist layer, on the same surface of the wiring pattern as the surface where the solder resist layer is formed.