SnAgCu

This alloy composition (with or without the addition of a fourth element) appears to be the most popular replacement. This alloy has also been chosen to be the benchmark, with SnPb being the baseline, for testing any other alloys to be included in the listing to be provided to the industry.

Concerns with this alloy family include higher processing temperatures and their compatibility with lead bearing finishes. It should also be noted that metals cost for this alloy are about 2.2 to 2.7 times that of SnPb eutectic at current market values.

SnCu

This alloy composition is a low cost alternative for wave soldering, its main area of use and is compatible with most lead bearing finishes. Process considerations must be addressed with this alloy, which has a higher melting temperature than most SnAgCu alloys. This alloys is also 1.5 times more expensive than SnPb eutectic at current market values.