ASSESSMENT OF LOW-TEMPERATURE FLUXES

The subject of this paper is the evaluation of the wetting balance as a technique for studying the flux activity of newly developed low-temp erature solder paste fluxes. The most effective configuration of the w etting balance was the standard configuration with only one change: th e PbSn eutectic solder was replaced with a eutectic solder alloy with a melting point of 58 degrees C. Since 58 degrees C is significantly l ess than the proposed activation temperatures of the solder fluxes, we tting curves asa function of temperature could be studied for each of the fluxes. The resulting data was used to rank the fluxes in terms of their activation requirement.