Abstract: The Cu/solder interfacial stress singularity in solder joints for different shapes and solder materials are evaluated based on the theory of interfacial mechanics.The interfacial stresses are computed by the finite element method to investigate the influence of solder joint shapes,solder materials and material models on the interfacial stress distribution.Results show that a fatter solder shape increases the interfacial singularity,and the singularity of Sn37Pb/Cu interface is greater than those of Sn3.5Ag/Cu and Sn3.0Ag0.5Cu/Cu interfaces.Elastic-plastic deformation and strain effects of the solder under drop/impact loadings reduce the interfacial stresses.