Fatigue performance of Cu/Sn–3.0Ag–0.5Cu/Cu solder joints at different current densities

In this study, the low cycle shear fatigue performance and fracture behavior of microscale ball grid array (BGA) structure Cu/Sn–3.0Ag–0.5Cu/Cu solder joints with various shear amplitudes were systematically investigated at different current densities by experimental, theoretical methods and finite element analysis. The experimental results showed that the fatigue life of the solder joint decreased with increasing shear amplitude and current density. The descent rate of fatigue life decreased with increasing shear amplitude at the same current density. Moreover, the deterioration of current stressing on the fatigue life of the solder joint was more serious at the lower shear amplitude. In addition, with increasing current density, the solder joint fracture position transitioned from the solder matrix to the solder/IMC layer interface, and the shape of the fracture path shifted from arc-shape to flat-shape.