A LOWER-MELTING POINT SOLDER ALLOY FOR SURFACE MOUNTS

Significant manufacturing cost reductions can be realized with lower-t emperature surface mount processing by increasing yields and using les s expensive components and boards. A lower-melting-point solder alloy (nominal composition Sn-41.75Pb-8Bi-0.5Ag) has been developed that ena bles significant reductions in peak reflow temperatures during surface -mount assembly. The solder alloy is compatible with standard Pb-Sn su rface finishes, melts within the temperature range of similar to 166-1 72 degrees C, and has promising mechanical properties.