抄録
Sn-Ag-Cu solder materials have been used widely. However, the cost is increased by containing Ag. In this paper, tensile and low cycle fatigue properties of Sn-3.0Ag-0.5Cu and Sn-1.0Ag-0.7Cu were obtained at strain rate of 10-4/s order and room temperature. The difference between Sn-3.0Ag-0.5Cu and Sn-1.0Ag-0.7Cu couldn't be recognized for Young's modulus or low cycle fatigue strength. The yield stress and tensile strength of Sn-3.0Ag-0.5Cu were over those of Sn-1.0Ag-0.7Cu. On the other hand, the elongation of Sn-3.0Ag-0.5Cu was lower than that of Sn-1.0Ag-0.7Cu. Using obtained properties, inelastic finite element analysis for a power device was carried out under a thermal cyclic load conditions with large scale stress strain analysis code. The inelastic strain range was 0.45% at the edge of interface between the solder layer and alumina substrate and the fatigue life was estimated at 8,200 cycles.
