LEAD-FREE AND ANTIMONY-FREE SOLDER ALLOY, SOLDER BALL, AND SOLDER JOINT

摘要

Provided are a lead-free and antimony-free solder alloy, a solder ball, and a solder joint capable of suppressing fusion failure as a result of having improved shear strength, which is attributed to the refinement of crystal grains at junction interfaces. This lead-free and antimony-free solder alloy has an alloy composition comprising, in terms of mass percentage, 0.1-4.5% of Ag, 0.20-0.85% of Cu, 0.005-0.090% of Ni, and 0.0005-0.0090% of Ge, the balance being Sn. The alloy composition satisfies formulas (1) and (2).　(1): 0.006 ≤ (Ag + Cu + Ni) × Ge < 0.023(2): (Sn/Cu) × (Ni × Ge) / (Ni + Ge) < 0.89In the formulas (1) and (2), Ag, Cu, Ni, Ge, and Sn represent respective contents in the alloy composition (mass%).