| 摘要 |
PROBLEM TO BE SOLVED: To provide a solder material capable of forming a solder part having excellent thermal fatigue properties.SOLUTION: A solder material has a composition of Sn-Ag-Bi-Cu-In or Sn-Ag-Cu-In. Ag (where excepting the case that Ag is 0.5 mass% and 1.0 mass%) in 0.3≤[Ag]<4.0, Bi in 0≤[Bi]≤1.0 and Cu in 0.5≤[Cu]≤1.2 are included when the percentage content (mass%) of Ag, Bi, Cu and In in the solder material are [Ag], [Bi], [Cu] and [In] respectively. In within the range of 5.2+(6-(1.55×[Cu]+4.428))≤[In]≤6.8 is included within the range of 0.5≤[Cu]≤1.0. In within the range of 5.2≤[In]≤6.8 is included within the range of 1.0<[Cu]≤1.2. |
