Sensitivity analysis on solder joint fatigue life of solid state drives by finite element method and Monte Carlo simulation

Abstract

We proposed a method to estimate a distribution of fatigue life of solid state drives (SSDs) due to thermal cycling excitation by using finite element method and Monte Carlo simulation. In the developed finite element model, we utilized the Anand model to represent the viscoplastic behavior of the solder balls, and we also utilized the Prony series to represent the viscoelastic behavior of the polymer material in underfill. We determined a fatigue life of the SSD by using the Morrow’s energy-based fatigue model. Finally, we determined a distribution of fatigue life considering the manufacturing tolerance of the design variables and the variation of material properties in the Monte Carlo simulation. Finite element analysis shows that the outermost solder ball at the corner of dynamic random access memory was the most vulnerable component under the thermal cycling excitation. We also show that temperature profile and diameter of solder ball affect dominantly the fatigue life of the SSD.