The Kester 977 is an organic water soluble, water-based, no-clean chemistry for high quality soldering of electronic circuit board assemblies. Designed for wave soldering applications, 977 provides good wetting on most surface finishes. The flux was specifically designed to reduce bridging, which is commonly associated with VOC-free, no-clean fluxes. 977 has excellent soldering properties for improved productivity without sacrificing reliability of the assembly. - The flux leaves bright shiny solder joints and will not attack properly cured solder masks or FR-4 Epoxy-Glass laminate. The minimal amount of residue remaining after soldering is non-conductive, non-corrosive and does not need to be removed. The residues left after soldering will not interfere with in-circuit testing. 977 is not detrimental to the Surface Insulation Resistance (SIR) of the soldered assembly.