WIRING BODY STRUCTURE AND FORMATION METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To easily heat up a solder bump on a wiring layer, with almost no solder delay and by setting height from a wiring layer to a scheduled value. SOLUTION: A wiring layer is formed on an insulation substrate, where the wiring layer is in a configuration such that a first metal conductor layer and a second metal conductor layer with lower solderability than it are laminated in this order with the second metal conductor layer as a surface side. Also, on the second metal conductor layer of the wiring layer, a metal electrode layer for piling up solder bumps with higher solderability than the second metal conductor layer is formed.