Lead free alloys for soldering applications are available in a variety of compositions. Alternatives under consideration today share the characteristic of higher melting points than eutectic tin-lead. Because of the similarity of its properties to eutectic tin-lead, tin-silver-copper alloys, commonly referred to as SAC, have received the greatest amount of attention and are successfully being used in the early stages of implementation of lead free assembly. Eutectic tin-copper + nickel, a newer alloy that is gaining success, melts at 227℃, 10℃ higher than SAC alloys. Higher melting points require higher processing temperatures for wave solder machines, reflow ovens and rework stations.
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