Effect of Elastic-Plastic Anisotropy of Solder Grains on Variability of Cyclic Mechanical Bending Durability in SAC305 CSP Assembly

SAC solder joints contain a few large grains and are hence termed oligocrystalline. Solder joints represent heterogeneous anisotropic behavior which affect durability of solder joint during thermal and mechanical loading conditions. In this paper, variability in durabiity of solder joints under cyclic mechanical bending of CSP assemblies was studied. A global 3D slice model of CSP package was used anddisplacement were transferred to a more detailed local model of the critical solder joint, using a submodeling approach. Further simulations were conducted on this critical CSP joint. Local model results were compared with global model.