| abstract |
(57) [Problem] To provide a microetching agent capable of roughening a copper surface into a shape having deep irregularities excellent in adhesiveness to a solder resist or the like and excellent in solderability. SOLUTION: Sulfuric acid 1 to 50% by weight, hydrogen peroxide 0.1 A copper and copper alloy microetching agent comprising an aqueous solution containing from 0.0001 to 3% by weight of at least one of tetrazole and a tetrazole derivative. |