The Effect of Aging on Microstructures Evolution and Shear Behaviors in Lead-free Solder Joint

摘要

In this paper, the influence of aging treatment on microstructures evolution and shear strength in Sn-3.0Ag-0.5Cu, Sn-4.0Ag-0.5Cu and Sn-3.5Ag lead-free solders were investigated. For comparison, the specimens as-soldered and after aging at temperature of 100°C were respectively put up observation for IMC and shear test.Morphology, microstructure and component at interface of solder joint were observed and analyzed. The results show that morphology and microstructure of intermetallic compound change form long needle-like to scallop-like, and the thickness and quantity of intermetallic compound increases with increasing aging time. Shear load of the lead-free solder joint decreases at constant strain rate with increasing aging. At the identical work condition, the shear load of solder joint with different lead-free alloy had not significantly change.Sn-3.5Ag presents the better shear property than the others