The effects of Mn powder additions on the microstructures and tensile property of SnAgCu/Cu solder joints

摘要

In this paper, the effects of Mn powder on fusion property of Sn3.0Ag0.5Cu solder alloy and micro-structures as well as tensile property of the solder joints of Sn3.0Ag0.5Cu/Cu were investigated by differential scanning calorimetry analysis, scanning electron microscopy and tensile tests. The results showed that the addition of Mn dramatically suppressed under cooling of SnAgCu solder alloy. Mn addition contributed to the growth of Cu_6Sn_5 intermetallic compound layers since it provided nucleation sites for Cu_6Sn_5 at the solder joints. Moreover, Mn addition increased the hardness of the solder alloys and reduced the tensile strength of SnAgCu/Cu solder joints. During aging, the growth of IMC layers of SnAgCuMn/Cu solder joints was slower than that of SnAgCu/Cu solder joints, and the tensile strength of all the solder joints increased after aging.