Method of soldering with phosphoric acid soldering flux
AssigneeAllegheny Ludlum Industries, Inc.
InventorEdward G. Choby, Jr.
Life of this patent
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Abstract
A phosphoric acid flux with good fluxing efficiency and high viscosity, and one which is especially suitable for use in the soldering of copper, stainless steel and copper-plated stainless steel. The flux is in the form of a viscous fluid, or a thermally unstable emulsion when the fluid is combined with a pasty vehicle. The viscous fluid contains phosphoric acid, copper containing material and an organic material (molecular weight between 4,000 and 20,000) from the group consisting of polyethers and polyimines or mixtures thereof having an atomic ratio of carbon to ether oxygen plus imine nitrogen between 1.5 and 3.1.
Claims11
In the soldering of copper, stainless steel and copper-plated stainless steel wherein metal selected from the group consisting of copper, stainless steel and copper-plated stainless steel is placed in close proximity with other metal, solder and soldering flux, and wherein said solder is melted and applied to said metals in such a way that it solidifies and effects a bond therebetween;
- the improvement which comprises utilizing a soldering flux comprised of a viscous fluid;
- said fluid consisting essentially of, in weight percent, 25 to 80% phosphoric acid (based on a concentration of 75 to 95%), 15 to 65% of organic material selected from the group consisting of polyethers and polyimines and mixtures thereof having an atomic ratio of carbon to ether oxygen plus imine nitrogen between 1.5 and 3.1, from 0.1 to 15% of copper containing material, from 0 to 40% of ammonium salt, and from 0 to 30% water;
- said organic material having a molecular weight between 4,000 and 20,000.
Dependencies are inferred from the claim text.