Study on life-prediction of solder joint under combined loading

A life-prediction approach of solder joints under combined thermal and vibration loading is provided in this paper.The deformations of solder joints are calculated respectively under vibration and thermal cycling loading based on finite element method.The calculated results are defined as boundary conditions of the multiaxial loading to investigate the strain/stress of the solder joints.Then the life of solder joints is calculated.The result reveals that the life of solder joints can be divided into three regions according to the vibration amplitude at the same temperature: the life of solder joints in region Ⅰ is affected by thermal loading;that in region Ⅱ is greatly affected by the combined loading;that in region Ⅲ is affected by the vibration amplitude.The trend of the simulation results basically agrees with that of the test results.