STRUCTURE FOR MOUNTING ELECTRONIC APPARATUS

摘要

PROBLEM TO BE SOLVED: To resolve problems of an electronic component not being operated normally for a long term because stripping occurs between an external connection pad of an electronic apparatus and solder by which the pad is connected to an external electric circuit substrate. SOLUTION: A copper-nickel-tin alloy 21, which is formed between a nickel plating layer 17 for coating the external connection pad 15 of the electronic apparatus 1 and solder 3 for connecting the layer 17 to the external electric circuit substrate 2, is formed with small crystals having a grain size of 3μm or smaller and large crystals having a grain size of 5 to 50μm and the large crystals are made to produce more than the small crystals.