It is required to remove the residues of OA fluxes? You will get corrosion if you do not fully remove all the flux residues. The flux residues from organic fluxes are hygroscopic, they contain organic acids and they may contain halides. Over time the residues will absorb moisture and the halides will become mobile and corrosive. This will lead to ‘catastrophic failure’ of the assembly in question. We recommend cleaning with an aqueous cleaning system, it can be either batch type or in-line. The water temperature should be between 120-140°F. The important thing is to have lots of rinsing and flushing to completely remove all the flux residues. Source: Kester Solder Co.