Zn-Based Solders for High Temperature Electronic Application

Abstract

Finding a suitable solder alloy to completely replace Pb-based high temperature solders in electronic packaging applications is a crying need for sustenance and further upgradation of the present technology. Currently, Zn-based alloys have been emerged as potential candidate in substituting health hazardous Pb containing solders. This review focuses on the recent research in development of Zn-based high temperature solders comparing their microstructural, thermal, mechanical, electrical properties, and reliability issues with conventional high temperature solder alloys including Au–Sn and Pb–Sn. The major alloys discussed here include Zn–Al-based, Zn–Sn-based, and pure Zn with trace element addition. Significant changes in structures and properties of the alloys due to addition of several alloying elements in different composition have been critically analyzed and their suitability in desired application has been assessed focusing on the relative properties and reliability of conventional solders. Finally, conclusion was drawn that further research and development of Zn-based high temperature solders is essential for replacement of conventional Pb-based high temperature solders.