Study of Zn-Sn-Al solder alloys

Abstract

In the electronic industry Pb-Sn solder is a very important material but Pb is toxic and has adverse effects on the environment and human beings. Due to the harmful effects of the Pb the use of the Pb-Sn solder alloys are being avoided and new Pb-free solder alloys are being used for electronic applications. The Sn – Zn – Al alloys are one of significant candidates in the proposal of alternative lead-free solders for high temperature soldering. Three Sn – Zn – Al alloys were prepared and studied experimentally. The micro-hardness and X-ray micro-analysis of the samples were conducted. The specimens were studied metallographically including SEM (BSE) in order to determine the composition and identification of individual phases. Melting point and significant temperatures of the alloys are found by DSC and TGA analysis. The diagram of the Al – Sn – Zn ternary system is given thermodynamically more precisely on the basis of our complex study. The fracture analysis wa also done with the help of FESEM. The basic difference between the eutectic solder and addition of Aluminium was observed. Economics of the processing of the solder was briefly discussed.