温度サイクル負荷時におけるLSIパッケージの封止樹脂クラックに関する解析

抄録

Numerical stress analysis of resin cracking occurring in LSI packages during temperature cycling tests was carried out using a thermoelastic finite element method for nonlinear contact problems. Through the use of the linear fracture mechanics approach, the analysis provides a fracture parameter and indicates the direction in which resin cracking occurs. Temperature cycling tests using actual LSI packages were also performed to verify the validity of the analyses. It was found that the test results agreed well with the analytical results and that leadframe materials and the delamination occurring between dissimilar materials determine quantitatively the tendency of resin cracking. The resin cracking mechanism was also studied and countermeasures against it were proposed.