Kester 920-CXF is a low solids no-clean organic flux designed for wave soldering conventional and surface mount circuit board assemblies. This flux eliminates defects often experienced in surface mount assembly wave soldering operations with traditional fluxes. This non-corrosive and nonconductive flux has an extremely low solids content. There is essentially no residue left on the assembly after soldering. There are no residues to interfere with electrical testing and the expense of cleaning is eliminated. PCB assemblies are dry as they exit the wave solder machine. The surface insulation resistance is higher than that provided by typical organic water-soluble fluxes. Electrical reliability of the assembly is assured. This flux formulation is suitable for soldering bare copper and solder plated circuit boards. It is advised that bare copper boards be free of excessive oxides and other contamination for optimum soldering performance.