ABSTRACT
Lead-tin (Pb-Sn) solders have been utilized in electronic packages and assemblies for more than 40 years to attach components to printed circuit boards (PCBs) owing to their unique combination of properties of low melting point, wetting, and mechanical characteristics, and are relatively inexpensive. In addition, these materials are compatible with component lead and finish materials, and allow processing in a temperature range in which card materials and components maintain their integrity even when exposed to multiple thermal excursions as happens during rework operations. Lead-tin solders have demonstrated a high level of compatibility with electronics assembly processing and materials over the years with only a few exceptions, most notable is the effect of even relatively minor gold concentrations to cause embrittlement within solder joints [1].
