Effect of RE on Microstructure and Interfacial Reactions of SnAgCu Solder

Effect of rare earth content on microstructure and interfacial reactions of low Ag content SnAgCu solder is researched by adopting the X-ray diffraction, JSM-5610LV scanning electronic microscope, energy spectrum analysis and JEM2100 ultrahigh resolution electron microscopy. The results show that proper quantities of rare earth (0.1%) can refine the eutectic microstructure of the solder alloy; and petal-like rare earth compound can be found in the solder alloy while the rare earth addition is 0.5%. The growing rate of the interfacial intermetallic compound can be reduced during the soldering with adding 0.1% rare earth in the Sn2.5Ag0.7Cu solder alloy.