Development of lead-free solder alloys for electronic assembly
The objective of this project is to develop lead free solder alloys with superior mechanical and physical properties. For various reasons (some mentioned above), Sn-based multicomponent alloys with alloying elements, Ag, Cu and/or Bi are likely to be the most promising  . For further improvement of Sn-based solder joints, in this work the effects of alloying and/or micro-alloying elements (e.g., Bi, Ag, Cu, Zn, Al, Sb, Ge, Se…) on microstructure, mechanical properties, interfacial reactions, wettability, reliability and melting behavior of Sn-based solders are investigated. In this project the problems associated with the existing lead-free solders, such as formation of large brittle intermetallic compounds, high melting temperature, tin whisker growth and high cost need to be resolved. The proposal detail is summarized in the following.