Study on fatigue reliability evaluation for lead free solder joints

In this study, the aim is to establish the efficient method of life evaluation with checking it´s consistent with real test. Firstly, as to the effect of hardening rule, differences between analysis result of isotropic and that of kinematic are small and analysis time of kinematic is longer than that of isotropic. Isotropic hardening is more effective, and its utility is higher than that of kinematic. Secondly, as to the effect of element size, the differences of analysis results between element size of soldier joints=6.25[μm] and 12.5[μm] is almost none, and analysis time of 12.5[μm] is shorter, so using 12.5[μm] is more efficient. Thirdly, as to the effect of the number of deleting elements of every fatigue crack analysis, it should be decided in just proportion not to grow cracks by taking wrong route.