| abstract |
The invention relates to an etching liquid, provides a nickel etching liquid which can inhibit the etching to metals except nickel, in particular copper. The etching liquid is a nickel etching liquid containing nitric acid or sulfuric acid, hydrogen peroxide and water, which is characterized in that it contains a polymer, and the polymer is selected from at least one repeating unit of the following formula (I), the following formula (II), and the following formula (III), wherein, R1-R5 are identical or different, are selected from hydrogen group, amino group, imino group, cyano group, azo group, mercapto group, sulfo group, hydroxyl group, carbonyl group, carboxyl group, nitro group, alkyl group, cycloalkyl group, aryl group or benzyl group, and amine contained in the repeating unit is in quaternary ammonium salt form or not in quaternary ammonium salt form. |