Effect of rare earth on mechanical creep–fatigue property of SnAgCu solder joint

In this paper, the effects of rare earth (RE) element additions on the mechanical creep–fatigue property of the Sn3.8Ag0.7Cu solder joint have been investigated. The results show that adding a small amount of the RE elements can evidently increase the creep–fatigue rupture lifetime of the Sn3.8Ag0.7Cu solder joint. The increase in the creep–fatigue property can be attributed to the reduction of the creep–fatigue damages and the change of microcrack propagation site during the fracture process, which depends on the refining of intermetallic compounds due to the RE elements. In addition, it is also found that adding the RE elements decreases the strain amplitude of the solder joint under the constant stress amplitude.