Tin-silver-copper has received much publicity in recent years as the lead-free solder of choice. The IPC Solder Value Product Council SAC305 (Sn96.5 Ag3.0 Cu0.5) was endorsed by as the preferred option for SMT assembly, and most assemblers have transitioned to this alloy for their solder paste requirements. However, due to the 3.0% silver content, the SAC305 is expensive when compared to traditional Sn63Pb37. For this reason, many wave assemblers are opting for less costly options, such as tin-copper based solders, for their wave, selective and dip tinning operations.

This article was taken from Global SMT & Packaging Vol. 6 No. 10 - November/December 2006.

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