POST-TREATMENT AFTER ETCHING WITH HYDROGEN PEROXIDE AND SULFURIC ACID

摘要

PURPOSE:To prevent the defective fusing of the solder surface of an etched wiring board by blackening, by treating the board with alkali metallic hydroxide and a compound such as silicate or phosphate. CONSTITUTION:A printed wiring board is etched with an etching soln. contg. hydrogen peroxide and sulfuric acid as the principal components. The etched board is treated with a post-treating agent obtd. by blending alkali metallic hydroxide with one or more kinds of compounds selected among silicates, phosphates, borates and aliphatic oxycarboxylates.