A fundamental computational study of 3-D non-planar fracture in solder joints

A sub-modeling approach involving a combination of nonlinear finite element method (FEM) and peridynamic (PD) theory analyses for prediction of 3-D non-planar fracture propagation in solder joints is presented. The procedure is demonstrated by considering a BGA type package with peripheral array solder joints. FEM is used as the global model to identify the critical solder joint and the displacement field acting on it. The PD model uses the FEM-calculated displacements as boundary conditions. The solder joint is considered to be composed of grains; four distinct cases of different grain sizes are considered. Propagation of fatigue cracks in 3-D as well as dissipated energy due to failure are presented. Comparisons between different micro-structures are made.