Analysis on solder ball shear testing conditions with a simple computational model

This paper introduces a simple computational model for the analysis on the solder ball shear testing conditions. Both two-dimensional (2-D) and three-dimensional (3-D) finite element models are used to investigate the effect of shear ram speed on the solder ball shear strength of plastic ball grid array (PBGA) packages. An effective thickness is identified for the 2-D finite element analysis. By using this effective thickness as a scale factor, it is shown that the 2D model is feasible for the study of 3-D problems. The computational model is validated by experimental data in terms of load-displacement curves. The results from both testing and modeling indicate that the shear ram speed has a substantial effect on the solder ball shear strength. In general, faster ram speed can result in higher ball shear strength. Therefore, the characterization of solder ball shear strength is loading rate-dependent.