Reliability prediction of different size solder bumps in thermal shock test using FEM

Three-dimensional structure has been achieved using interlayer connecting technology with double-side solder bump and the lifetime of the solder joints under thermal shock test has been forecasted by finite element method. The simulation result presents that the stress at the interface between 0.76mm solder bump and PCB is evidently higher than that in other places. The interface between 0.76mm solder bump and PCB A is the fracture position in experimental test which indicates that the stress distribution of 0.76mm solder bump is accurate and the finite element model is reasonable. The simulation results have indicated that the size of solder bump has a significant influence on the reliability of Sn63Pb37 solder interconnections under thermal shock tests. The predicted lifetime of 0.76mm diameter solder bump is 259 cycles while that of 2mm diameter solder bump is up to 3605 cycles.