Delamination modeling for IC package with multiple initial cracks

Package delamination is a critical reliability problem which may cause thermal management and electrical problems. In this paper, package delamination with multiple initial crack for SOIC package is simulated and analyzed by FEA. The strain energy release rate (delamination driving force G), CTE stresses and effects of moisture vapor pressure (acting on the crack surface) are studied. Major investigations include: (1) the impact of multiple crack delamination versus one single crack delamination. Typical examples are how the multiple cracks, which locate at the same interface and/or appear simultaneously at the interfaces of die surface with EMC, die attach with pad, pad with EMC, will interact each other and delaminate the package. (2) Impact of moisture vapor pressure after moisture diffusion at 85C/85%RH, will he studied for the multiple crack delamination. Through this study, a better understandmg of SOIC package delamination may be obtained.