Properties of Two Lead-Free Solder Alloys and Comparison with Sn37Pb
The microstructures and properties of Sn3Ag2.8Cu and Sn3Ag2.8Cu-0.1Ce solder alloys were investigated by means of OM, SEM and EDX and compared to that of Sn37Pb. The results show that the wettability of Sn3Ag2.8Cu-0.1Ce is more favorable, Sn3Ag2.8Cu exhibits poorer wetting behaviour compared to that of Sn37Pb solder; the conductivities of Sn3Ag2.8Cu-0.1Ce and Sn3Ag2.8Cu soldesr are almost 20 percent and 8 percent higher than that of Sn37Pb respectively; the fractography of tensile specimen of Sn3Ag2.8Cu is smooth and light, and is a quasi-cleavage fracture mechanism, whereas that of Sn3Ag2.8Cu-0.1Ce is dark and rough, and has a fibrous pattern, and is a ductile fracture mechanism; the fractography of Sn3Ag2.8Cu-0.1Ce includes more compact and more uniform dimples than that of Sn3Ag2.8Cu, this is cause of the trace amounts of Ce refining the microstructure; brazing with the Cu substrate, the diffusion layer of Sn3Ag2.8Cu solder with Cu substrate includes more irregular IMC compared to Sn3Ag2.8Cu-0.1Ce and Sn37Pb..
Zhengyi Jiang, Xianghua Liu and Jinglong Bu
T. H. Xu et al., "Properties of Two Lead-Free Solder Alloys and Comparison with Sn37Pb", Advanced Materials Research, Vols. 154-155, pp. 540-544, 2011