A scale reduced computation scheme for peeling stress of solder joints under drop impact

Abstract

A beam model of board level electronic package was used to investigate effects of the moment, axial force and shear force induced during drop/impact on the peeling stress of the soldered joints. The peeling stresses in soldered joints were evaluated under static and dynamic bending of the PCB. It shows that the peeling stress is dominated by the bending stress and the maximum occurs at the PCB end. In the soldered joint array, only a few soldered joints closed to the far end of the packaging are stressed and the most joints inside the array are almost stress free. Based on this observation, an approach was proposed to reduce the computation scale. By the approach, only 3 or 4 soldered joints are necessary to be included in the computational model.