Numerical simulation and analysis on thermal coupling effect of MCM packaging

System-in-package (SiP) has been adapted as one of the most promising packaging technologies with the development of mobile devices. It could greatly reduce the package size and enhance the device performance. As the electronic packaging technology progresses quickly, various SiPs have been designed and the structure of SiP is becoming more diversified. However, the relatively complex structure of SiP may cause unexpected failure during practical application. In this paper, a 3D package with one larger chip and four smaller chips on the front and back side of a FR4 board respectively was designed to study the reliability of SiP. The devices experienced a set of reliability tests including temperature cycling tests and drop tests under JEDEC standards. Furthermore, double-layer stacked samples were assembled and went through drop tests. Finally, failure analysis was carried out to find out the failure mechanism.