Thermal cycling aging effects on the tensile property of lead-free solder Sn-3Ag-0.5Cu

Structural reliability issues attract more and more attentions with the rapid development of electronic packaging industry. Sn-Ag-Cu alloys have long been used as solder materials for the interconnections of microelectronic devices because of low melting temperature and good wettability. Many tensile tests were performed on Sn-3Ag-0.5Cu solder alloys at various strain rates and over a wide temperature range [I]. And thermal cycling aging studies on a lead-free Sn-Ag-Cu solder joint were investigated [2]. In this study, a series of tensile tests of Sn-3Ag-0.5Cu were investigated at different number of cycles and different temperatures. The possible mechanism of tensile strength, ductility improvement were discussed. The samples were placed in liquid nitrogen environment at 77 K for 10 minutes and then 293K(398K) for 10 minutes as one thermal cycle. The number of cycles is 5, 15, 25 and 35. Thermal cycling induces changes in properties.