FORMATION OF TERMINAL ELECTRODE FOR SOLDER BUMP MOUNTING

PROBLEM TO BE SOLVED: To prevent solder from flowing into an interface between a wiring electrode pad and an insulating protective film and to reduce the number of fabricating steps to achieve low fabricating costs, by forming the insulating protective film and then making the insulating film act as a plating resist to form a bump adhesive layer. SOLUTION: A wiring electrode pad 2 is formed on an insulating substrate 1, and then subjected to an oxidation process to from an oxidized layer 8. An insulating protective film 3 is then formed in such a manner that a surface of the oxidized layer 8 is partially exposed. Subsequently formed on the oxidized layer 8 in the insulating protective film 3 is a bump adhesive layer 5 made of nickel and gold. Formed only on the exposed bump adhesive layer 5 is a solder bump 4. Since the insulating protective film 3 wherein only an area for formation of an terminal electrode for bump mounting is opened is previously formed to function as a resist in this way, the terminal electrode for solder bump mounting can be easily formed.