Patent ID: 7337941

Claim:
A method of making a flux-coated aluminum brazing sheet comprising: (a) combining a brazing flux with polyvinyl butyral binder to form a first mixture, wherein the brazing flux has an initial brazing flux particle size, wherein the brazing flux comprises a metal element; (b) shearing said first mixture to form a second mixture having dispersed brazing flux particles in said second mixture, wherein about 100% of the dispersed brazing flux particles have a final brazing flux particle size on the order of about 1 micron or less, and said shearing step further reduces the initial brazing flux particle size by at least about 50% to the final brazing flux particle size; (c) combining said second mixture with an organic solvent to form a brazing flux mixture; (d) coating at least a portion of the surface of an aluminum brazing sheet with said brazing flux mixture; and (e) drying said brazing flux mixture on said aluminum brazing sheet surface.