Thermal-mechanical reliability assessment of TSV structure for 3D IC integration

In this paper, thermal-mechanical reliability of TSV structure was investigated with thermal shock test and finite element method. The fine pitch TSV samples were subjected to thermal load, failure samples were identified by resistance measurement, the calculated characteristic life was about 340 cycles. It is revealed that thermal-mechanical stress is concentrated around TSV, the ends of TSV are susceptible to failure. FEA results indicate maximum value of maximum principal stress appears at chip area near the ends of TSV, scallop side wall induces larger shear stress than smooth side wall thus more easily leads to interfacial failure. The warpage of chips and fatigue life of solder balls under different thermal load conditions were investigated in global simulation.