Characterization of Stress-Strain Response of Lead-Free Solder Joints Using a Digital Image Correlation Technique and Finite-Element Modeling

Author(s)
Golta Khatibi, Martin Lederer, E. Byrne, Agnieszka Betzwar-Kotas, Brigitte Weiss, Herbert Ipser
Abstract

The stress-strain response of miniaturized Sn-Ag-Cu (SAC) lead-free solder joints in the thickness range of 80 mu m to about 1.1 mm was studied. A high-resolution three-dimensional (3D) digital image correlation system was used for in situ measurement of displacement and strain fields in the solder joints during tensile testing. These measurements showed that the localization of plastic strain and stress buildup occurs mainly at the interface of the solder. With increasing solder gap thickness the size of the plastically deformed zone in the solder increases, resulting in transformation of a brittle interfacial fracture to a ductile fracture within the bulk of the solder. The experimental deformation plots of solder joints and strain-rate-dependent tensile tests on bulk solder material were used to establish a new constitutive material model for the solder. This strain-rate- and pressure-dependent material model was implemented in ABAQUS through the user subroutine CREEP. In agreement with the experiments, the finite-element method simulation revealed a pronounced thickness effect leading to higher tensile strength of thinner solder joints.

Organisation(s)
Physics of Nanostructured Materials, Department of Functional Materials and Catalysis
External organisation(s)
Correlated Solutions, Inc.
Journal
Journal of Electronic Materials
Volume
42
Pages
294-303
No. of pages
10
ISSN
0361-5235
DOI
https://doi.org/10.1007/s11664-012-2276-2
Publication date
2013
Peer reviewed
Yes
Austrian Fields of Science 2012
102009 Computer simulation, 104011 Materials chemistry, 103018 Materials physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/characterization-of-stressstrain-response-of-leadfree-solder-joints-using-a-digital-image-correlation-technique-and-finiteelement-modeling(5db1287c-ec7d-4341-bf62-406abf00c5c8).html