Process for improving adhesion of polymeric materials to metal surfaces
View Patent ↗A process for treating metal surfaces that includes first contacting the metal surface with a particular acidic peroxide adhesion promoting composition, followed by contacting that metal surface with an aqueous acid post-dip composition to provide a micro-roughened surface. This treatment is particularly suitable for treating metal surfaces used in printed circuit multilayer construction.
1. A method of adhering a polymeric resin to a metal surface, said process comprising:
(a) contacting the metal surface with an adhesion promoting composition;
(b) thereafter contacting the metal surface with an aqueous acid post-dip composition to provide a microroughened metal surface; and
(c) thereafter adhering a polymeric resin to said microroughened metal surface wherein the polymeric resin is adhered to the microroughened metal surface without any additional processing steps between the steps of contacting with acid post-dip composition and adhering the polymeric resin to the metal surface.
2. A method of adhering a polymeric resin to a metal surface, said process comprising:
(a) contacting the metal surface with an adhesion promoting composition;
(b) thereafter contacting the metal surface with an aqueous acid post-dip composition to provide a microroughened metal surface; and
(c) thereafter adhering a polymeric resin to said microroughened metal surface
wherein the adhesion promoting composition comprises:
(a) an oxidizer;
(b) an acid;
(c) a corrosion inhibitor;
(d) optionally, a source of halide ions; and
(e) optionally, a water soluble polymer.
3. The method according to claim 2 wherein the oxidizer is selected from the group consisting of hydrogen peroxide and persulfates.
4. The method according to claim 2 wherein the acid is a mineral acid.
5. The method according to claim 2 wherein the corrosion inhibitor is selected from the group consisting of triazoles, benzotriazoles, imidazoles, benzimidazoles, tetrazoles and mixtures of the foregoing.
6. The method according to claim 2 wherein the water soluble polymer is selected from the group consisting of polymers of ethylene oxide, ethylene oxide-propylene oxide copolymers, polyethylene glycols, polypropylene glycols, polyvinyl alcohols, and mixtures of the foregoing.
7. The method according to claim 2 wherein the source of the metal surface comprises copper.
8. The method according to claim 2 wherein the source of halide ions is selected from the group consisting of alkali metal halide salts and oxohalide salts.
9. The method according to claim 8 wherein the source of halide ions is source of chloride ions.
10. The method according to claim 2 , wherein the acid post-dip composition comprises hydrochloric acid.
11. The method according to claim 10 , where the concentration of the hydrochloric acid in the acid post-dip composition is between about 2% and about 12% by weight.
12. The method according to claim 11 , wherein the concentration of the hydrochloric acid in the acid post-dip composition is between about 4% and about 10% by weight.
13. The method according to claim 2 , wherein the acid post-dip composition is maintained at a temperature of between about 15 and about 20° C.
14. The method according to claim 2 , wherein the acid post-dip composition is applied by spray coating, immersion coating, curtain coating and combinations of one or more of the foregoing.