GeorgeBynum
Active Member
Agreeing 100% with @mansr ; there are eutectic non-lead solders, both 2 metal, 3 metal, and other. From Wikipedia,You seem to have things a little mixed up. Eutectic means there is a single, well-defined melting point. Non-eutectic solder has a range of temperatures within which it is neither solid nor melted. Even a slight movement as it cools through this range can result in a bad joint. With eutectic solder, this is less of a concern since it solidifies almost instantly.
Tin-silver-copper (Sn-Ag-Cu, or SAC) solders are used by two-thirds of Japanese manufacturers for reflow and wave soldering, and by about 75% of companies for hand soldering. The widespread use of this popular lead-free solder alloy family is based on the reduced melting point of the Sn-Ag-Cu ternary eutectic behavior (217 °C, 423 °F), which is below the 22/78 Sn-Ag (wt.%) eutectic of 221 °C (430 °F) and the 59/41 Sn-Cu eutectic of 227 °C (441 °F).[19] The ternary eutectic behavior of Sn-Ag-Cu and its application for electronics assembly was discovered (and patented) by a team of researchers from Ames Laboratory, Iowa State University, and from Sandia National Laboratories-Albuquerque.