The effect of Pb content on the solidification behavior and shear performance of Sn3.0Ag0.5Cu/Cu joint

The effect of Pb content in the rang of 0~37wt.% on solidification behavior and shear performance of Sn3.0Ag0.5Cu/Cu joint was investigated. It was shown that Pb contamination showed a significant influence on the solidification behavior of Sn3.0Ag0.5Cu/Cu joint. A little amount of Pb resulted in the formation of ternary eutectic Sn-Pb-Ag phase with a low melting temperature and a mushy region between primary solidification phase and Sn-Pb-Ag phase during solidification stage of mixed joint. The mushy zone decreased with the increasing of Pb content and disappeared when Pb content in solder matrix of joint exceeded 18.34wt.% The addition of Pb in Sn3.0Ag0.5Cu/Cu joint has been shown to be beneficial to improve the shear force of SAC/Cu joint by using ball shear test method and the shear force of single interface mixed solder joint was in parabolic relationship with Pb content. The formation of ternary eutectic Sn-Pb-Ag phase and mushy zone in solidification stage had no obvious influence on the shear force of mixed solder joint.