abstract |
The present invention relates to environmentally safe aqueous cleaning compositions for cleaning electronic circuit assemblies, such as printed circuit or printed wiring boards, during their fabrication. Alkali metal carbonate and bicarbonate salts are utilized with an alkali metal silicate to achieve a variety of objectives, among which are the removal of solder flux, oils, waxes, and greasy substances, adhesives and other residues as well as provide anti-corrosion protection and metal brightening. |