Process for increasing the adhesion of a metal surface to a polymer

1 . A process for increasing the adhesion of a copper or copper alloy surface to a material comprising polymers, said process comprising:

a) contacting the copper or copper alloy surface with a composition comprising:

1. water;

2. a source of cupric ions;

at a pH from 2.8 to 4.2;

such that a conversion coating is formed on the copper or copper alloy surface.

2 . A process according to claim 1 , wherein the composition is substantially free of azole compounds.

3 . A process according to claim 1 wherein the composition also comprises a buffer.

4 . A process according to claim 4 wherein the buffer is selected from the group consisting of potassium or sodium carbonate, sodium citrate and sodium hydrogen phosphate, and potassium hydrogen phthalate and sodium hydroxide.

5 . A process according to claim 1 wherein the source of cupric ions is selected from the group consisting of cupric sulfate, cupric chloride, cupric acetate and mixtures of the foregoing.

6 . A process according to claim 1 wherein the pH is from 3 to 4.

7 . A process according to claim 3 , wherein the composition is substantially free of azole compounds.

8 . A process according to claim 7 wherein the buffer is selected from the group consisting of potassium or sodium carbonate, sodium citrate and sodium hydrogen phosphate, and potassium hydrogen phthalate and sodium hydroxide.

9 . A process according to claim 8 wherein the source of cupric ion source selected from the group consisting of cupric sulfate, cupric chloride, cupric acetate, and mixtures of the foregoing.

10 . A process according to claim 9 wherein the pH is from 3 to 4.