Open Access

ARTICLE

Numerical Implementation of a Unified Viscoplastic Model for Considering Solder Joint Response under Board-Level Temperature Cycling

by Hung-Chun Yang, Tz-Cheng Chiu^*

Department of Mechanical Engineering, National Cheng Kung University, Tainan, 701, Taiwan

* Corresponding Author: Tz-Cheng Chiu. Email:

Computer Modeling in Engineering & Sciences 2021, 128(2), 639-668. https://doi.org/10.32604/cmes.2021.016159

Received 12 February 2021; Accepted 29 April 2021; Issue published 22 July 2021

Abstract

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.

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