H.-P. Wei, Y.-H. Yang, and B. Han
Mechanical Engineering Department, University of Maryland, College Park, MD 20742, USA
A comprehensive stochastic model is proposed to predict Package-on-Package (PoP) stacking yield loss. The model takes into account all pad locations at the stacking inter-face while considering the statistical variations of the warpages and the solder ball heights of both top and bottom packages. The goal is achieved by employing three statis-tical methods: (1) an advanced approximate integration-based method called eigenvector dimension reduction (EDR) method to conduct uncertainty propagation (UP) analyses,(2) the stress-strength interference (SSI) model to determine the noncontact probability at a single pad, and (3) the union of events considering the statistical dependence to calculate the ?nal yield loss. In this ?rst part, theoretical development of the proposed stochastic model is presented. Implementation of the proposed model is presented in a companion paper.