| 摘要 |
A solder ball is provided which suppresses interface peeling in a bonding interface of a solder ball, which suppresses fusion defects which develop between the solder ball and a solder paste, which has a low occurrence of failure at the time of dropping of electronic parts, and which can be used with Ni electrodes such as those plated with Au and Cu electrodes coated with a water-soluble preflux. The present invention is a lead-free solder ball for electrodes of a BGA or CSP comprising 0.5 - 1.1 mass % of Ag, 0.7 - 0.8 mass % of Cu, 0.05 - 0.08 mass % of Ni, and a remainder of Sn. Even when a printed circuit board to which the solder ball is bonded has Cu electrodes or Au-plated or Au/Pd-plated Ni electrodes, the solder ball has good resistance to drop impacts. The composition may further contain at least one element selected from Fe, Co, and Pt in a total amount of 0.003 - 0.1 mass % or at least one element selected from Bi, In, Sb, P, and Ge in a total amount of 0.003 - 0.1 mass %. |
