Patent ID: 8192636

Claim:
A method of applying a polymeric material to a copper or copper alloy surface, which method comprises: (a) treating the copper or copper alloy surface with an etching solution comprising: (i) a ferric ion source; (ii) a buffer of an organic acid and its corresponding salt; (iii) a halide ion source; and (iv) an accelerator; wherein the accelerator is selected from the group consisting of urea, thiourea, guanidinium salts, sulfosalicylic acid, niacinamide, cyanates, thiocyanates, triazoles, benzotriazoles, imidazoles, benzimidazoles, tetrazoles, isocyanates and amino acids and wherein the ferric ion concentration is in the range of 1-50 g/1; and (b) applying the polymeric material to the treated copper or copper alloy surface.