Effect of Temperature on the Fatigue Damage of SAC305 Solder

In recent years, the field of electronic packaging has been rapidly developing. The traditional lead-containing solders have been abandoned because of their pollution to the environment and harm to human body. Therefore, lead-free solders are gradually beginning to be used in the electronic packaging industry, among which, the Sn-3.0Ag-0.5Cu (SAC305) solder is the most frequently used material in lead-free solder. As the fundamental elements, solder joints in electronic components are affected by periodical mechanical stress and strain for the while service life, so it is important to understand the fatigue damage about them. In this paper, SAC305 solder specimens were experimentally investigated to uniaxial cyclic loading at different temperatures from 288.15K to 373.15K under the same strain rate of $\mathbf{10^{-3}/\mathrm{s}}$ and the same maximum strain of 0.10. In order to explain the accumulative damage due to fatigue at different temperatures and the mechanical properties, SAC305 solder specimens after cyclical loading were tested through tensile force until fracture at the same temperature. Furthermore, the differences of microstructure were observed by a scanning electron microscope (SEM). It could be known that the fatigue damage of the specimens is different at different temperatures, and the failure morphology of the solder specimens also varies.