Triethanolamine-Modified Flux for Hand Soldering
Original Publication Date: 1985-Aug-01
Included in the Prior Art Database: 2005-Feb-19
One drawback associated with the use of certain solder fluxes containing ethanol as a solvent is the need to wash the workpiece within three hours of flux contact in order to avoid the formation of a black tarnish. This tarnish has been tentatively identified as copper oxide, and its presence on solder bond pads could pose a reliability hazard. There is an additional problem in that evaporation of the ethanol can produce a crusty residue which is sometimes hard to remove. Both these problems can be circumvented by removing most of the ethanol solvent by evaporation at reduced pressure and replacing it with triethanolamine (TEA). TEA is a clear, high boiling, low vapor pressure, slightly viscous, completely water-soluble liquid with a remarkable low order of toxicity.