Constitutive model and numerical analysis for high lead solder interconnects

High lead solder interconnects are extensively used in the electronic industry. This paper uses a unified creep plasticity (UCP) constitutive model to numerically simulate the mechanical performance of such interconnects under thermomechanical cyclic loading. The UCP model is capable of incorporating thermal and cyclic hardening effects. To make the model more objective, cyclic loading induced damage was also incorporated. The model is programmed into the commercially available FEM software ABAQUS. A uniaxial tension case was analyzed to verify the model and reasonable agreement with experimental results was achieved. A typical three-dimensioned (3D) solder bump under shear loading was analyzed and the strain/stress distribution within the solder bump was obtained.