A numerical approach on life-prediction of solder joints under combined loading for chip ackaging system

The aim of this paper is to provide a numerical approach to predict the lifetime of solder joints by considering combined loading based on the damage superposition. The deformations of solder joints are calculated under vibration and thermal cycling loading respectively. The calculated results are defined as boundary conditions of the multi-axial loading. The strain/stress is investigated by finite element method based on the Chaboche model. The fatigue damage and creep damage are calculated by using the Manson-Coffin equation. It reveals that there is a strong non-linear impact on the lifetime due to the interaction of the combined loading. The trend of the simulation results basically agrees with that of the tests results. The approach can be used to predict the solder joint lifetime under combined loading. © 2011 Inderscience Enterprises Ltd.