SOLDERING MATERIAL, SOLDERED JOINT, AND METHOD FOR INSPECTING SOLDERING MATERIAL

摘要

The present invention accurately distinguishes a soldering material which is less apt to oxidize. The soldering material is Cu-core balls which comprise: Cu balls that have a given size and ensure a space between a semiconductor package and a printed board; and a solder layer with which each Cu ball has been coated. After a 72-hour burning test in a 150ºC thermostatic chamber inside a room having a temperature of 25ºC and a humidity of 40%, the Cu-core balls have a lightness according to the L*a*b* color system of 62.5 or greater. Before the burning test, the soldering material has a lightness according to the L*a*b* color system of 65 or greater and a yellowness according to the L*a*b* color system of 7.0 or less.