FINITE ELEMENT IMPLEMENTATION TO TIME-DEPENDENT CONSTITUTIVE MODEL OF SOLDER IN MICRO-ELECTRONIC PACKAGING

An existing time-dependent deformation constitutive model of 63Sn-37Pb solder alloy in micro-electronic packaging was implemented into ABAQUS using the interface package UMAT. Due to the complexity of this model, some modifications were made upon the traditional implicit algorithm. Based on the modification, the current internal variables were updated; the consistent tangent modulus was derived to improve the efficiency of iteration. To show the validity, various loading cases were carried out. The comparison between the implemented FEA simulations based on ABAQUS and the verified numerical constitutive modeling results of the existing model shows that the implemented FEA results coincide with the numerical constitutive simulations of the existing model perfectly. As a structural FEA example for the FEA implementation, a finite element simulation was conducted for the shear structural specimen of the material under cyclic loading.