Abstract
Numerical stress analysis of electronic packages during temperature cycling was carried out using a thermoelastic finite-element method (FEM). 3D technique was introduced into programming . Through the use of CG(conjugate gradient ) solver and CSR(compressed sparse row) storage scheme which was introduced in order to lower computation time and memory required, the result show they perform well. The programming was verified by ANSYS, a well-accepted finite-element programming used to analyze structure mechanism.Compared with 3D result, 2D result showed lower Von mise stress in the same sample point. The thickness of die and leadframe was changed to observe the response of the other materials. It was found thinner die decrease the Von mise stress on the other materials and thicker leadframe would increase the loading of the adhesive layer.