Effects of small amount addition of rare earth Y on microstructure and property of Sn3.0Ag0.5Cu solder

In the present work, effect of adding small amount of Y on the microstructure, physical and mechanical properties of Sn3.0Ag0.5Cu solder has been investigated. The purpose is to understand if the heavy rare earth Y has similar effect as light rare earth Ce or La on improving properties of SnAgCu lead-free solder. The results indicated that adding small amount of Y can evidently improve the wettability, mechanical strength and creep rupture life of the Sn3.0Ag0.5Cu solder alloy. It is pointed out that proper Y content in the Sn3.0Ag0.5Cu solder alloy should be in a range of 0.05~0.25wt%. Moreover, It is felt that the increase in mechanical strength may be related to the refining of IMCs of the solder due to the addition of small amount of Y. Copyright © 2014 Trans Tech Publications, Switzerland.