TY  - EJOU
AU  - Yang, Hung-Chun 
AU  - Chiu, Tz-Cheng 

TI  - Numerical Implementation of a Unified Viscoplastic Model for Considering Solder Joint Response under Board-Level Temperature Cycling
T2  - Computer Modeling in Engineering \& Sciences

PY  - 2021
VL  - 128
IS  - 2
SN  - 1526-1506

AB  - An implicit integration scheme was developed for simulating the viscoplastic constitutive behavior of Sn3.0Ag0.5Cu solder and programmed into a user material subroutine of the finite element software ANSYS. The numerical procedure first solves the essential state variables by using a three-level iterative procedure, and updates the remaining stress and state variables accordingly. The numerical implementation was applied to consider the responses of solder joints in an electronic assembly under temperature cycling condition. The viscoplastic strain energy density accumulation over one temperature cycle was identified as a feasible parameter for evaluating the thermomechanical reliability of the solder joints.
KW  - Pb-free; hysteresis; ratcheting; fatigue; tangent modulus

DO  - 10.32604/cmes.2021.016159