Reliability and thermal fatigue life prediction of solder joints for advanced automotive microelectronics

With the development of the automotive industry, the number of automotive electronic components is growing rapidly. This leads to new requirements for reliability of the automotive electronics. Especially, for difficult operating environments, such as engine compartment of the car, extreme thermal cycles, and long holding time, where prediction of the fatigue life of the component is particularly important. In this study, thermal fatigue life prediction models for two packages are proposed: TSOP over BGA, and flip chip with BGA. The overall deformation of the two packages was analyzed using Moiré fringes, and was found to be consistent with simulation results. The reliability of the model was verified by comparing thermal shock results and simulation results. Then, the fatigue life of the component under thermal cycles was predicted using the model. The overall component life of the BGA with flip chip package was 818 cycles. For TSOP over BGA this was 1005 cycles, but the shortest life of the BGA was 725 cycles, which may result in the failure of the entire component. The fatigue life prediction using different models is helpful to assess and optimize components at the early stage of product development.