Abstract
This work first investigated the initial location of the possible delamination in a plastic ball grid array (PBGA) package under moisture preconditioning and subsequent solder reflow by applying the modified Tsai-Hill failure criteria. The fracture parameters, such as the stress intensity factor (SIF), the strain energy release rate, and the phase angle at the delamination tip, were calculated to study delamination growth. A two-dimensional PBGA finite element model was considered and the hygrothermal stress at the interfaces was calculated to examine the initiation of delamination. A three-dimensional PBGA finite element model was applied in the study of three-dimensional delamination growth. A global-local finite element analysis and two-dimensional linear interfacial fracture mechanics were used to calculate fracture parameters at the delamination tip for different delamination lengths. The effect of vaporized moisture inside the PBGA package on the growing delamination was examined. A series of popcorn experiments on PBGA packages was carried out to verify the simulation results. The agreement between the predicted and experimental results was good. © 2006, Institution of Mechanical Engineers. All rights reserved.