Thermo-mechanical stresses for a triple junction of dissimilar materials: Global-local finite element analysis

Finite element analysis with conventional elements fails to provide convergent stresses in regions where a free edge with a bimaterial interface or a junction of dissimilar materials exists. However, these regions are characteristic of electronic devices, and they are the most critical locations for failure. A finite element analysis with global (special) and local (conventional) elements has been developed to provide an accurate description of the stress field at these locations. The global elements capture the singular nature of the stresses arising from geometric and material discontinuities. With this method, the designer can accurately evaluate the thermo-mechanical integrity of various electronic devices.