Microstructure of Soldering Joint of Rapidly Solidified Sn2.5Ag0.7Cu Solder Alloy

Rapidly solidified Sn2.5Ag0.7Cu solder alloy was prepared by single roller process.The effects of normal state and the rapidly solidified soldering on microstructure,fracture morphology,interfacial compound and properties of the purple copper joints were investigated by using SEM,EDS and tensile tester.The results show that compared with the normal state solder alloy,the joint microstructure obtained by brazing with the solidification solder was refined.The primary phase size of β-Sn decreased and its amount increased.The eutectic structure decreased obviously,and the boundary between the primary phase and eutectic phase got fuzzy.There were more dimples formed during shear fracture.The toughness of soldering joints was improved.