Creep behavior of eutectic 80Au/20Sn solder alloy

Eutectic 80Au/20Sn solder alloy is widely used in high power electronics and optoelectronics packaging in which the creep property of the solder joint is essential to meet the global demand for longer operating lifetime in their applications. In this study, the tensile creep behavior of bulk eutectic 80Au/20Sn solder alloy is reported and compared with 63Sn37Pb solder joint. The creep strain rate increases and creep lifetime decreases as the applied stress level and temperature increase. The 80Au/20Sn solder alloy shows a superior anti-creep performance over the 63Sn37Pb solder joint. The experimental data were successfully fit with Dorn model and Garofalo model. However, the application of Garofalo model resulted in a lower estimated variance of error terms as compared to the Dorn model. Grain boundary sliding is the possible creep mechanism within the given stress level and temperature. The nucleation, accumulation and further growth of microvoids lead to the creep rupture.