ANTI-TARNISH COATINGS

• US 20100291303A1
• Filed: 11/21/2007
• Published: 11/18/2010
• Est. Priority Date: 11/21/2007
• Status: Active Grant

• Current Assignee: MacDermid Enthone Inc. (Element Solutions Inc)
• Original Assignee: Enthone Incorporated (Element Solutions Inc)
• Inventors: Abys, Joseph A., Sun, Shenliang, Antonellis, Theodore
• Granted Patent: US 7,972,655 B2
• Time in Patent Office: Days
• US Class Current: 427/343
• CPC Class Codes: C08K 5/17 Amines; Quaternary ammonium compounds
• CPC Class Codes: C08K 5/37 Thiols
• CPC Class Codes: C09D 5/086 Organic or non-macromolecular compounds
• CPC Class Codes: C09D 7/45 Anti-settling agents
• CPC Class Codes: C09D 7/63 organic
• CPC Class Codes: C23C 18/54 Contact plating, i.e. electroless electrochemical plating
• CPC Class Codes: C23F 11/10 using organic inhibitors
• CPC Class Codes: C23F 11/149 Heterocyclic compounds containing nitrogen as hetero atom
• CPC Class Codes: C23F 11/161 Mercaptans
• CPC Class Codes: H05K 2203/122 Organic non-polymeric compounds, e.g. oil, wax or thiol
• CPC Class Codes: H05K 2203/124 Heterocyclic organic compounds, e.g. azole, furan
• CPC Class Codes: H05K 3/244 Finish plating of conductors, especially of copper conductors, e.g. for pads or lands selective plating methods H05K3/243; finish plating of conductors made by printing techniques H05K3/246; solder as finish H05K3/3457, e.g. by plating H05K3/3473
• CPC Class Codes: H05K 3/282 for inhibiting the corrosion of the circuit, e.g. for preserving the solderability

Abstract

A method is disclosed for enhancing the corrosion resistance of a surface of a copper or copper alloy substrate. The method comprises depositing a metallic surface layer comprising a precious metal on a surface of the copper or copper alloy substrate by immersion displacement plating and exposing the electronic device to an aqueous composition comprising a first organic molecule comprising at least one functional group that interacts with and protects precious metal surfaces and a second organic molecule comprising at least one functional group that interacts with and protects copper surfaces.

Claims

1. A method for enhancing the corrosion resistance of a surface of a copper or copper alloy substrate, the method comprising:

depositing a metallic surface layer comprising a precious metal on the surface of the copper or copper alloy substrate; and

exposing the copper or copper alloy substrate having the metallic surface layer thereon to an aqueous composition comprising (a) a first organic molecule comprising at least one functional group that interacts with and protects precious metal surfaces, (b) a second organic molecule comprising at least one functional group that interacts with and protects copper surfaces, and (c) a surfactant.

2. The method of claim 1 wherein the metallic surface layer is deposited by an immersion displacement plating process, and the metallic surface layer comprises silver, gold, or a combination thereof.

3. The method of claim 1 wherein the first organic molecule is selected from the group consisting of thiols (mercaptans), disulfides, thioethers, thioaldehydes, thioketones, and combinations thereof.

4. The method of claim 3 wherein the first organic molecule is a thiol having the following general structure (I):

R₁—

S—

H  

 

Structure (I)

wherein R₁ is either a hydrocarbyl having between one carbon atom and about 24 carbon atoms or an aryl having between about five and about fourteen carbon atoms.

5. The method of claim 4 wherein the thiol is selected from the group consisting of ethanethiol;

1-propanethiol;

2-propanethiol;

2-propene-1-thiol;

1-butanethiol;

2-butanethiol;

2-methyl-1-propanethiol;

2-methyl-2-propanethiol;

2-methyl-1-butanethiol;

1-pentanethiol;

2,2-dimethyl-1-propanethiol;

1-hexanethiol;

1,6-hexanedithiol;

1-heptanethiol;

2-ethylhexanethiol;

1-octanethiol;

1,8-octanedithiol;

1-nonanethiol;

1,9-nonanedithiol;

1-decanethiol;

1-adamantanethiol;

1,11-undecanedithiol;

1-undecanethiol;

1-dodecanethiol;

tert-dodecylmercaptan;

1-tridecanethiol;

1-tetradecanethiol;

1-pentadecanethiol;

1-hexadecanethiol;

1-heptadecanethiol;

1-octadecanethiol;

1-nonadecanethiol; and

1-icosanethiol; and

combinations thereof.

6. The method of claim 4 wherein the thiol is selected from the group consisting of benzenethiol;

2-methylbenzenethiol;

3-methylbenzenethiol;

4-methylbenzenethiol;

2-ethylbenzenethiol;

3-ethylbenzenethiol;

4-ethylbenzenethiol;

2-propylbenzenethiol;

3-propylbenzenethiol;

4-propylbenzenethiol;

2-tert-butylbenzenethiol;

4-tert-butylbenzenethiol;

4-pentylbenzenethiol;

4-hexylbenzenethiol;

4-heptylbenzenethiol;

4-octylbenzenethiol;

4-nonylbenzenethiol;

4-decylbenzenethiol;

benzyl mercaptan;

2,4-xylenethiol, furfuryl mercaptan;

1-naphthalenethiol;

2-naphthalenethiol;

4,4′

-dimercaptobiphenyl; and

combinations thereof.

7. The method of claim 3 wherein the first organic molecule is a disulfide having the following structure (II):

R₁—

S—

S—

R₂  

 

Structure (II)

wherein R₁ and R₂ are each independently either a hydrocarbyl having between one carbon atom and about 24 carbon atoms or an aryl having between about five and about fourteen carbon atoms.

8. The method of claim 7 wherein the disulfide is selected from the group consisting of diethyl disulfide, di-n-propyl disulfide, diisopropyl disulfide, diallyl disulfide, di-n-butyl disulfide, di-sec-butyl disulfide, diisobutyl disulfide, di-tert-butyl disulfide, di-n-pentyl disulfide, di-neopentyl disulfide, di-n-hexyl disulfide, di-n-heptyl disulfide, di-n-octyl disulfide, di-n-nonyl disulfide, di-n-decyl disulfide, di-n-dodecyl disulfide, di-n-tridecyl disulfide, di-n-tetradecyl disulfide, di-n-pentadecyl disulfide, di-n-hexadecyl disulfide, di-n-heptadecyl disulfide, di-n-octadecyl disulfide, di-n-decyl disulfide;

diundecyl disulfide, didodecyl disulfide, dihexadecyl disulfide, dibenzyl disulfide, dithienyl disulfide, 2-naphthyl disulfide, and combinations thereof.

9. The method of claim 1 wherein the second organic molecule is selected from the group consisting of primary amines, secondary amines, tertiary amines, aromatic heterocycles comprising nitrogen, and combinations thereof.

10. The method of claim 9 wherein the second organic molecule is a primary amine, secondary amine, or a tertiary amine having the following general structure (III):

11. The method of claim 10 wherein the amine is selected from the group consisting of aminoethane, 1-aminopropane, 2-aminopropane, 1-aminobutane, 2-aminobutane, 1-amino-2-methylpropane, 2-amino-2-methylpropane, 1-aminopentane, 2-aminopentane, 3-aminopentane, neo-pentylamine, 1-aminohexane, 1-aminoheptane, 2-aminoheptane, 1-aminooctane, 2-aminooctane, 1-aminononane, 1-aminodecane, 1-aminododecane, 1-aminotridecane, 1-aminotetradecane, 1-aminopentadecane, 1-aminohexadecane, 1-aminoheptadecane, 1-aminooctadecane, and combinations thereof.

12. The method of claim 9 wherein the second organic molecule is an azole having the following general structure (IV):

13. The method of claim 12 wherein the azole is selected from the group consisting of pyrrole (1H-azole);

imidazole(1,3-diazole);

pyrazole(1,2-diazole);

1,2,3-triazole;

1,2,4-triazole;

tetrazole;

isoindole;

indole(1H-benzo[b]pyrrole);

benzimidazole(1,3-benzodiazole);

indazole(1,2-benzodiazole);

1H-benzotriazole;

2H-benzotriazole;

imidazo[4,5-b]pyridine;

purine(7H-imidazo(4,5-d)pyrimidine);

pyrazolo[3,4-d]pyrimidine;

triazolo[4,5-d]pyrimidine; and

combinations thereof.

14. The method of claim 12 wherein the azole is selected from the group consisting of 2-(3,4-dichlorobenzyl)-benzimidazole;

2-bromobenzyl benzimidazole;

2-bromophenyl benzimidazole;

2-bromoethylphenyl benzimidazole;

2-chlorobenzyl benzimidazole;

2-chlorophenyl benzimidazole;

2-chloroethylphenyl benzimidazole; and

combinations thereof.

15. The method of claim 1 wherein the first organic molecule is present in a concentration between about 1 and about 10 g/L and the second organic molecule in a concentration between about 1 and about 10 g/L.

16. A method for enhancing the corrosion resistance of a surface of a copper or copper alloy substrate, the method comprising:

depositing a metallic surface layer comprising silver and/or gold on the surface of the copper or copper alloy substrate; and

exposing the copper or copper alloy substrate having the metallic surface layer thereon to an aqueous composition comprising (a) a first organic molecule in a concentration between about 1 and about 10 g/L selected from the group consisting of thiols (mercaptans), disulfides, thioethers, thioaldehydes, thioketones, and combinations thereof that interacts with and protects precious metal surfaces, (b) a second organic molecule in a concentration between about 1 and about 10 g/L selected from the group consisting of primary amines, secondary amines, tertiary amines, aromatic heterocycles comprising nitrogen, and combinations thereof that interacts with and protects copper surfaces, and (c) a surfactant.

17. A method for enhancing the corrosion resistance of a surface of a copper or copper alloy substrate, the method comprising:

depositing a metallic surface layer comprising silver and/or gold on the surface of the copper or copper alloy substrate; and

exposing the copper or copper alloy substrate having the metallic surface layer thereon to an aqueous composition comprising (a) a first organic molecule of 1-octadecanethiol in a concentration between about 1 and about 10 g/L, (b) a second organic molecule in a concentration between about 1 and about 10 g/L selected from the group consisting of primary amines, secondary amines, tertiary amines, aromatic heterocycles comprising nitrogen, and combinations thereof that interacts with and protects copper surfaces, and (c) a surfactant.