Wiring board and its production method, semiconductor device and its production method, and electronic apparatus

摘要

There are provided a high density and low manufacturing cost wiring board with high reliability in connection, a semiconductor device and a producing method therefor.The invention relates to a wiring board comprising a board having an electrode and being coated with an insulation layer with a hole for exposing the electrode; a wiring consisting of a Cr or Ti layer, which is connected to the electrode and closely contacts with the insulation layer, and of a Cu layer which is closely contacts with the Cr or Ti layer; a protective film which covers the wiring and is provided with another hole for soldering; and a solder for the outer connection which is mounted in the both holes and brought to diffuse into the Cu layer to produce an alloy, and brought to reach the Cr or Ti layer thereby connecting the solder to the Cr or Ti layer.