Cu core ball, solder paste, formed solder, Cu core column, and solder joint

摘要

Provided are a Cu core ball and a cu core column, which achieve dropping strength and strength against heat cycle. The Cu core ball (1) contains a Cu ball (2) made of Cu or a Cu alloy and a solder layer (3) which is made of a solder alloy composed of Sn and Cu and covers the Cu ball (2). The solder layer (3) contains not less than 0.1% through not more than 3.0% of Cu and the remainder is composed of Sn and impurities.