Fatigue life prediction of flip-chips in terms of nonlinear behavior of solder and underfill

The nonlinear properties of eutectic solder and underfill FP4526 have been reported and incorporated into ABAQUS material model library for the fatigue life prediction of advanced electronic packages. The methods of unified constitutive modeling, separated constitutive modeling, and fatigue life prediction have been described and compared in detail. The nonlinear constitutive modeling of solder alloys and underfills plays an important role in the life prediction in terms of the correct calculation of inelastic strain range and inelastic strain energy density of hysteresis loop under various accelerated test conditions. Combined with unified constitutive modeling, strain-based approach of life prediction is recommended in this paper. The analyses performed in this report present valuable insights for the design of advanced flip-chip packages