Method for roughening copper surfaces for bonding to substrates

1. A process for preparing roughened copper surfaces suitable for subsequent multilayer lamination, said process comprising the steps of: contacting with a clean copper surface an adhesion promoting composition under conditions effective to provide a roughened copper surface, said adhesion promoting composition consisting essentially of:

hydrogen peroxide;

a pH adjuster;

a 5-membered aromatic fused N-heterocyclic ring compound, wherein the N-heterocyclic ring has a nitrogen atom at position 1 bonded to a hydrogen atom; and

a uniformity enhancer having the formula:

wherein R1 and R2 are independently selected from hydrogen or hydroxyl, amino, alkyl, hydroxyalkyl, aminoalkyl, nitroalkyl, mercaptoalkyl, or alkoxy groups;

wherein said adhesion promoting composition is at least essentially free of halogen ions.

2. The process according to claim 1 , wherein said process is preceded with the step of cleaning said copper surface.

3. The process according to claim 1 , wherein said process further comprises the step of contacting the uniform roughened copper surface with a post-dip.

4. The process according to claim 3 , wherein said post-dip comprises an azole or silane compound or a combination of said azole and said silane.

5. The process according to claim 4 , wherein said post-dip further comprises a titanate, zirconate, aluminate or a combination of said titanate, zirconate and aluminate.

6. The process of claim 4 , wherein said silane is selected from the group consisting essentially of

3-methylacryloyloxypropyltrimethoxysilane,

3-(N-styrylmethyl-2aminoethylamino) propyltrimethoxysilane hydrochloride,

3-(N-allyl-2-aminoethylamino)-propyltrimethoxysilane hydrochloride,

N-(styrylmethyl)-3-aminopropyltrimethoxysilane hydrochloride,

N-2-aminoethyl-3-aminopropyltrimethoxysilane,

3-(N-Benzyl-2-aminoethylamino)-propyltrimethoxy silane hydrochloride,

beta-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-aminopropyl-triethoxy silane,

gamma-glycidoxypropyltrimethoxysilane, and

vinyltrimethoxysilane.

7. The process of claim 5 , wherein said titanate is selected from the group comprising titanate amine, tetraocytl di(ditridecyl)phosphito titanate, tetra(2,2-diallyloxymethyl) butyl-di(ditridecyl)phosphito titanate, and neopentyl(diallyl)oxy-tri (dioctyl)pyrophosphatotitanate, and neopentyl(diallyl)oxytri-(m-amino)phenyl titanate.

8. The process of claim 5 , wherein said zirconate is selected from the group comprising tetra (2,2 diallyloxymethyl)butyl, di(ditridecyl)phosphito zi rconate, neopentyl(diallyl)oxy, trineodecanoyl zirconate, neopentyl(diallyl)oxy, tri(dodecyl)benzene-sulfonyl zirconate, tetra (2,2 diallyloxymethyl)butyl-di (ditridecyl)phosphito zirconate, and zirconium IV 2,2-dimethyl 1 ,3-propanediol.

9. The process of claim 5 , wherein said aluminate is selected from the group comprising diisobutyl(oleyl)acetoacetylaluminate, and diisopropyl(oleyl)acetoacetyl aluminate.

10. The process according to claim 1 , wherein said uniformity enhancer is 5-aminotetrazole.

11. The process according to claim 1 , wherein said adhesion promoting composition further consists essentially of a copper salt.

12. The process according to claim 2 , wherein said step of cleaning said copper surface comprises the step of applying a cleaning solution to said copper surface.

13. The process according to claim 12 , wherein said step of cleaning said copper surface further comprises the step of draining excess cleaning solution from the copper surface.

14. The process according to claim 1 , wherein said uniformity enhancer is selected from the group consisting of 5-aminotetrazole; 5-methyltetrazole; 5-methylaminotetrazole; 1H-tetrazol-5-amine; 1H-tetrazol-5-amine, N, N-dimethyl-1 -methyltetrazole; 1-methyl-5-mercaptotetrazole, 1 ,5-dimethyltetrazole; 1-methyl-5-aminotetrazole; and 1-methyl-5-methylamino-tetrazole.