ABSTRACT
Inherent toxicity of lead makes it a bad choice as a constituent in the solder alloy. Numerous alloys with different element compositions were invented to replacement for the existing Lead-Tin (Sn-Pb) alloy. Cost is a major factor in selecting the alloy. In this paper composition of elements (in wt.%) in the alloys and the cost of the element (per kg) were taken as the variables. All other costs were assumed to be constant. A cost benefit analysis was also done by comparing alloys along with their costs with melting points. Promising lead free alloys SAC305, SAC405 were compared with Sn-0.5Cu-3Bi-1Ag and Sn-1Cu-1Ni-1Ag by considering the cost and the properties. Analysis of the results shows that Sn-0.5Cu-3Bi-1Ag and Sn-1Cu-1Ni-1Ag are having good properties and cost benefit ratio when compared to the other alloys. These two alloys can be regarded as an alternative solder joints to replace Sn-Pb solder alloy.
