Sizes effect of CeSn3 on the whiskers growth of SnAgCuCe solder joints in electronic packaging

The relationship between Ce content/CeSn3 sizes and the whiskers growth is newly reported systematically. The whiskers growth can be observed in the surface of bulk CeSn3 particles, the rate of whisker growth was significantly slowed with Ce content lower than 0.1 wt%. At higher concentration of Ce, whisker growth rate becomes higher and noticeable. It is thought that the higher Ce chemical potential for oxidation provides a path for the mechanism of whisker growth. With all the other benefits of Ce addition, the potential to promote whisker growth indicate that only dilute concentration of Ce can be tolerated in SnAgCu alloys without whiskering effect. The results demonstrated that the trace amount of Ce can be utilized as additive into SnAgCu solder in microelectronic industry.