A simplified computational model for solder joints under drop impact loadings

The effects of the moment, axial force and shear force induced during drop impact on the peeling stress of the solder joints were investigated by a 2-D beam model and a 3-D solid model of board level electronic package. It shows that the peeling stress is dominated by the bending stress and the maximum occurs at the PCB end. Results of the two models indicated that in the solder joint array only a few solder joints closed to the end of the package are stressed and the most solder 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 solder joints are necessary to be included in the computational model.