Alkaline replenisher evaluation for printed wiring board evaluation

摘要

MacDermid's Metex(reg sign) Ultra Etch FL and modifications to the Ultra Etch FL chemistry were evaluated as replacements of a discontinued replenisher, Ultra Etch Aqueous. Ultra Etch FL with additions of water to lower the total alkalinity and ammonium chloride to maintain the chloride level was found to produce acceptable results and, in fact, had a similar chemical composition to Ultra Etch Aqueous.