| abstract |
(57) [Summary] [Objective] To provide an etching solution effective even for a copper alloy material which is difficult to clean the surface by forming a black smut with a conventional etching solution. [Constitution] An immersion etching solution for a copper / copper alloy material, which contains a peroxide or a persalt, and a carboxylic acid or a water-soluble salt thereof. Preferably, an aliphatic nitrogen compound selected from the group consisting of urea and its N-substituted derivative, thiourea and its N-substituted derivative, guanidine and its N-substituted derivative, and ethylene glycol, propylene glycol, diethylene glycol and di-ethylene. It further contains an alkylene glycol monoether selected from the group consisting of propylene glycol. |