Solder joint fatigue life prediction using peridynamic approach

Solder joint fatigue life prediction using peridynamic approach is presented for the first time. The underlying premise is that material degradation through energy dissipative mechanisms play a central role in crack initiation and propagation, and that fatigue cracks follow paths similar to cracks form under quasi-static loading. The new method uses peridynamic approach in simulating crack initiation as well as propagation. Dissipated energy in the vicinity of newly generated fracture surfaces are calculated as the cracks propagate. Once failure starts taking place, load rebalance leads to further propagation. The method is first demonstrated using controlled experimental measurements of compact tension test specimens that were subjected to mechanical loading only. The fatigue life predicted by simulations of compact tension test specimens is within 12% of the measurements. The methodology is then applied to solder joint fatigue problems. The nonlinear thermo-mechanical problem is first solved by finite element analysis for four thermal cycles. The most severe deformation configuration during the fourth thermal cycle at the most critical solder joint is identified and applied as the static loading in the peridynamic simulation. Number of cycles to crack initiation and propagation on five distinct packages are predicted. The combined finite element and peridynamic approach yielded predictions within 25% of the experimentally measured fatigue life values for four packages. In the fifth package, a close match is not achieved. Overall, the results point to the conclusion that the peridynamic approach has great potential to accurately predict solder joint fatigue life.