Joining of conductors by soldering is one of the basic technologies in the assembly of electronic circuits.
Solder provides mechanical strength. electrical continuity, and protection from the environment The most
commonly used solder alloy for joining electronic components to copper conductors is Sn/Pb. either 60
weight percent Sn and 40 weight percent Pb, or the eutectic 63Sn/37Pb. The soldering systems based on
these alloys have been highly developed and refined with decades of experience; much has been learned
about the metallurgy. mechanical properties, flux chemistries, manufacturing protocols, and reliability. In
electronic equipment assembly, soldering processes have been engineered to produce. at competitive costs.
very small geometry joints approaching 75 microns in size. Manufacturing engineers, generally speaking,
are extremely satisfied with SnPb solder, and are unlikely to welcome any change.