Characterization of the mechanical properties of actual solder joints using DIC

摘要

This paper presents the characterization of the elasto-plastic behavior of actual Sn-1.0wt.%Ag-0.5wt.%Cu (SAC105), Sn-3.0wt.%Ag-0.5wt.%Cu (SAC305) and Sn-4.0wt.%Ag-0.5wt.%Cu (SAC405) solder joints. Several actual ChipArray® BGA (CABGA) packages were cross-sectioned, polished and used as the test vehicles. Several testers were specially designed and fabricated for the characterization of the material properties using the customized test vehicle. Compressive and drop tests were performed to generate elastic and inelastic deformations, respectively, in the solder joints. Images of the cross-sectioned solder joints were recorded using microscope during the tests. The recorded images were then processed by using a digital image correlation (DIC) program to calculate the displacement and strain fields on the solder joints. Finite element method (FEM) modeling was used to extract the material properties.