This paper presents a multi-scale modelling approach to investigate the underpinning mechanisms of microstructure-sensitive damage of single crystal Sn-3Ag-0.5Cu (wt%, SAC305) solder joints of a Ball Grid Array (BGA) board assembly subject to thermal cycling. The multi-scale scheme couples board-scale modelling at the continuum macro-scale and individual solder modelling at the crystal micro-scale. Systematic studies of tin crystal orientation and its role in fatigue damage have been compared to experimental observations. Crystallographic orientation is examined with respect to damage development, providing evidence-based optimal solder microstructural design for in-service thermomechanical fatigue.
@article{arxiv.2204.05583,
title = {A multi-scale approach to microstructure-sensitive thermal fatigue in solder joints},
author = {Yilun Xu and Jingwei Xian and Stoyan Stoyanov and Chris Bailey and Richard J. Coyle and Christopher M. Gourlay and Fionn P. E. Dunne},
journal= {arXiv preprint arXiv:2204.05583},
year = {2022}
}