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Bibliographic Details
Main Authors: Xian, J. W., Xu, Y. L., Stoyanov, S., Coyle, R. J., Dunne, F. P. E., Gourlay, C. M.
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2311.03891
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author Xian, J. W.
Xu, Y. L.
Stoyanov, S.
Coyle, R. J.
Dunne, F. P. E.
Gourlay, C. M.
author_facet Xian, J. W.
Xu, Y. L.
Stoyanov, S.
Coyle, R. J.
Dunne, F. P. E.
Gourlay, C. M.
contents Thermal fatigue is a common failure mode in electronic solder joints, yet the role of microstructure is incompletely understood. Here, we quantify the evolution of microstructure and damage in Sn-3Ag-0.5Cu joints throughout a ball grid array (BGA) package using EBSD mapping of localised subgrains, recrystallisation and heavily coarsened Ag3Sn. We then interpret the results with a multi-scale modelling approach that links from a continuum model at the package/board scale through to a crystal plasticity finite element model at the microstructure scale. We measure and explain the dependence of damage evolution on (i) the beta-Sn crystal orientation(s) in single and multigrain joints, and (ii) the coefficient of thermal expansion (CTE) mismatch between tin grains in cyclic twinned multigrain joints. We further explore the relative importance of the solder microstructure versus the joint location in the array. The results provide a basis for designing optimum solder joint microstructures for thermal fatigue resistance.
format Preprint
id arxiv_https___arxiv_org_abs_2311_03891
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle The role of microstructure in the thermal fatigue of solder joints
Xian, J. W.
Xu, Y. L.
Stoyanov, S.
Coyle, R. J.
Dunne, F. P. E.
Gourlay, C. M.
Materials Science
Thermal fatigue is a common failure mode in electronic solder joints, yet the role of microstructure is incompletely understood. Here, we quantify the evolution of microstructure and damage in Sn-3Ag-0.5Cu joints throughout a ball grid array (BGA) package using EBSD mapping of localised subgrains, recrystallisation and heavily coarsened Ag3Sn. We then interpret the results with a multi-scale modelling approach that links from a continuum model at the package/board scale through to a crystal plasticity finite element model at the microstructure scale. We measure and explain the dependence of damage evolution on (i) the beta-Sn crystal orientation(s) in single and multigrain joints, and (ii) the coefficient of thermal expansion (CTE) mismatch between tin grains in cyclic twinned multigrain joints. We further explore the relative importance of the solder microstructure versus the joint location in the array. The results provide a basis for designing optimum solder joint microstructures for thermal fatigue resistance.
title The role of microstructure in the thermal fatigue of solder joints
topic Materials Science
url https://arxiv.org/abs/2311.03891