Finite element analysis on the factors affecting die crack propagation in BGA under thermo-mechanical loading

摘要

Ball grid array (BGA) is one of the most innovative semiconductor packaging technologies which is capable of high input-output capacities while addressing handling and coplanarity compared with other packages. However, the BGA package is subjected to thermo-mechanical load which makes it susceptible to quality and reliability issues such as die crack. The occurrence of die crack is difficult to monitor as it is considered as an internal package issue and can be catastrophic to the electronic device which may lead to its failure. This study aims to investigate the various factors affecting die crack propagation using finite element analysis (FEA) model under thermomechanical loads. The energy release rate in the silicon die was used to quantify the propagation of die crack in the BGA package. The influence of the various factors on the propagation of die crack was determined through a design of experiment approach consisting of the definitive screening for initial factor screening, and response surface method through the central composite design. The results have shown that the die thickness, the glass transition temperature, the in plane CTE of the substrate, and the initial crack length are the factors significantly affecting the die crack propagation in a BGA package. Moreover, at critical parameter conditions, the results have identified a critical crack length of 0.02236 mm. The study is aimed to benefit the research, design, development, assembly, and material engineers in the semiconductor industry providing insight to the die crack propagation of a BGA package.