Effects of Aging on Structures and Shear Strength of Interface of Sn-Ag-Cu Solder/Ni--P Plating Layer
老化对Sn-Ag-Cu焊料/Ni-P镀层界面结构和剪切强度的影响

Intermetallic compounds (IMC) near the interfaces of solder joints has significant effects on joint reliability. In this paper, 150 oC aging and high temperature reflow of Sn-3.5Ag-0.7Cu solder joints on Ni-P/Cu were performed. For two aging processes, the IMC growth, morphologies, compositions and their effect on joint reliability were studied. The results indicate that the IMC morphologies and compositions in condition of 150 oC aging were much different from that in condition of reflow. Long time 150 oC aging results in large clusters of Ag3Sn IMC in solder. Brittle Ni3P layer was found after high temperature reflow, which was absent in long time 150 oC aging.. Under both conditions, ternary Ni-Cu-Sn IMCs were observed between solder interfaces. The morphologies, compositions and thickness of IMC affected the strength of solder joints.