Thermal fatigue life evaluation of CSP joints by mechanical fatigue testing

The interrelation between a thermal cycle test and a mechanical shear fatigue test has been studied for CSP joints from the view point of fatigue life and the microstructural damage of solder joints. The fatigue lives in both methods are almost equivalent even though loading method is different. From the viewpoint of microstructure, the fact is attributed to that the transgranular failure is predominant mode and a microstructural coarsening which is induced by thermal loading and stress equivalent for both the thermal cycle test and the mechanical shear fatigue test.