STRUCTURE AND ELECTRICAL PROPERTIES OF Sn8Zn SOLDER ALLOY WITH Ag AND Ga ADDITIONS

Abstract

Solder joints based on eutectic SnZn alloy were studied. The influence of Ga and Ag was analysed and compared to the basic Sn8Zn alloy as well as to the reference solder alloys Sn60Pb40 and Sn3Cu. The formation of intermetallic layer in zinc-containing alloys made mainly out of Cu5Zn8 type was noted, while in the standard solder alloys it was Cu3Sn. The resistivity measurements showed the lowest value for Sn8Zn1Ag and the worst in the case of Sn8Zn1Ga, due to the quite different incorporation of Ag and Ga atoms in the solder: Ag atoms are found in precipitates while Ga atoms are dissolved in the matrix.