Abstract:
The Sn3.0Ag0.5Cu (SAC305) solder joints and Sn3.0Ag3.0Bi3.0In (SABI333) solder joints with the same size and similar crystal orientation were selected for tensile test at the same tensile speed. At the same time, single crystal solder joints and twin crystal solder joints with the same size in SABI333 solder joints were selected for tensile test at the same tensile speed. During the experiment, EBSD and SEM were used to characterize the crystal orientations and surface morphology of the solder joints. Results show that the tensile strength of SABI333 solder joints is much higher than that of SAC305 solder joints, and the two kinds of solder joints with different components have completely different fracture modes. SAC305 solder joints show ductile fracture, and SABI333 solder joints are broke after slight plastic deformation. In SABI333 solder joints, single crystal solder joints and twin crystal solder joints show different tensile properties in the process of drawing. The twin crystal solder joints show no plastic deformation in the process of drawing, and they are broke at the interface between solder matrix and copper bar.