Abstract: A non-toxic, non-corrosive liquid soldering flux consists essentially of a solution of citric acid in water. This unique flux produces solder joints of high metallic luster and excellent quality. Disposal presents no health hazards, and clean-up of flux residues is accomplished using only water.

Abstract: A non-toxic, non-corrosive foaming soldering flux (14) comprises citric acid and water, together with at least one foaming agent. The foam is fast-breaking, dissipating almost immediately. Such a fast-breaking foam is novel in an aqueous-based flux. The unique flux of the invention produces solder joints of high metallic luster and excellent quality. Disposal presents no health hazards, and clean-up of flux residues is accomplished using only water and, optionally, a surfactant.

Abstract: A non-toxic, non-corrosive water-soluble flux for cored solders comprises citric acid. The flux of the invention produces solder joints of high metallic luster and excellent quality. Clean-up of flux residues is accomplished using only water.

Abstract: A non-toxic, non-corrosive foaming soldering flux (14) comprises citric acid and water, together with at least one foaming agent. The foam is fast-breaking, dissipating almost immediately. Such a fast-breaking foam is novel in an aqueous-based flux. The unique flux of the invention produces solder joints of high metallic luster and excellent quality. Disposal presents no health hazads, and clean-up of flux residues is accomplished using only water and, optionally, a surfactant.

Abstract: Apparatus and methods for fluxing with water-soluble flux. A circuit card assembly has its solderable surface exposed for fluxing. A spray nozzle atomizes the flux to provide a mist that wets the surface without creating flux droplets. A pump is coupled between the spray nozzle and a container which stores the flux for pumping flux and atomizing the flux to create the flux spray. The apparatus may be used as a stand alone fluxing station for use with a liquid wave solder or vapor solder system. Alternatively, the apparatus may be used as an integral part of a wave soldering system that replaces the conventional fluxing station. In this embodiment, the apparatus is located beneath the conveyor and a sensor is used to actuate the flux spray. A plurality of nozzles or pluralities of sets of nozzles may be employed to achieve proper wetting of the assembly.

Abstract: A non-toxic, non-corrosive water-soluble soldering paste comprises at least about 80 wt % of particulate solder and the balance a thixotropic flux base. The flux base has a viscosity of at least about 200,000 cp and comprises (a) a botanical oil, (b) an aqueous emulsion of a thickening agent, such as corn starch or an ethoxylated linear alcohol in water, and (c) an organic acid having at least two carboxylic acid groups, such as citric acid. The paste of the invention produces solder joints of high metallic luster and excellent quality. Clean-up of paste residues is ac complished using only water.

Abstract: A non-toxic, non-corrosive liquid soldering flux is provided, comprising an organic acid, such as citric acid, and a non-toxic carrier, such as water. This unique flux produces solder joints of high mettalic luster and excellent quality. Disposal presents no health hazards, and clean-up of flux residues is accomplished using only water.