Robust power package development with mechanical simulation and reliability validation

Thermo-mechanical reliability is one of the major concerns for electronic packages, especially for power packages operating in extremely harsh environment. As the trends towards high density and function integration, advanced power device becomes more sensitive to environmental stress. Comprehensive study is needed from design, process to test towards robust power package with high reliability. In this paper, we will demonstrate the successful application of simulation in the development of a series of robust leaded power packages. Firstly, finite element analysis(FEA) has been carried out to understand die stress behavior inside the package during assembly and reliability tests, i.e. from die attach, post mold cure, reflow to thermal cycling etc. Then DOE matrix is run to obtain the critical responses to different factors, which leads to guidelines on package design and material selection. A series of robust power packages have been developed with optimized package geometry and bill of materials.