Lead-free solder, lead-free solder ball, solder joint using this lead-free solder, and semiconductor circuit having this solder joint

摘要

Ag: 1.2 to 4.5% by mass, Cu: 0.25 to 0.75% by mass, Bi: 1 to 5.8% by mass, Ni: 0.01 to 0.15% by mass, balance Sn It is a lead-free solder characterized by this. By using this addition amount, general solder characteristics such as wettability and shear strength characteristics could be further improved in addition to the thermal fatigue characteristics.