| Abstract Scope |
The eutectic Sn52In solder (118℃) is suitable for flexible electronics due to its low melting temperature and excellent conductivities. However, its low mechanical strength limits product reliability. In this study, we investigated the effect of Bi addition on Sn–In solder by using a Sn50In5Bi alloy. According to differential scanning calorimetry (DSC) analysis, the Sn50In5Bi solder alloy exhibited a melting point of 109.72 °C and a melting interval of 4.78 °C. Compared with the eutectic Sn52In solder, its melting point was reduced by approximately 10 °C.The mechanical properties of the alloy were evaluated. The ultimate tensile strength (UTS), yield strength, and the elongation of the alloy were 13.9MPa, 13.0 MPa, and 50.2% respectively. The fracture surface exhibited a ductile fracture mode characterized by the presence of dimples. Upon further solid-liquid reaction with Cu, needle-like Cu6(Sn,In)5 intermetallics were formed.
Keywords: Sn50In5Bi, Differential scanning calorimetry (DSC), Dimple, Cu6(Sn,In)5 |