SOLDER ALLOY POWDER AND SOLDER PASTE FOR BUMP, AND SOLDER BUMP USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide solder alloy powder and solder paste for a bump, which can suppress generation of a needle-like protrusion, and to provide a solder bump using the same.SOLUTION: Solder alloy powder for a bump has a component composition containing 2.8-4.2 wt.% Ag and 0.4-0.6 wt.% Cu and also containing 50-1,000 ppm of Bi and the balance consisting of Sn and unavoidable impurities. A solder paste for a bump is formed by mixing the solder alloy powder with flux together. Furthermore, a solder bump is formed by using the solder alloy powder for the bump.