Self assembled molecules on immersion silver coatings

• US 8,323,741 B2
• Filed: 07/10/2012
• Issued: 12/04/2012
• Est. Priority Date: 11/08/2007
• Status: Active Grant

• Current Assignee: MacDermid Enthone Inc. (Element Solutions Inc)
• Original Assignee: Joseph A. Abys, Shenliang Sun, Theodore Antonellis
• Inventors: Abys, Joseph A., Sun, Shenliang, Antonellis, Theodore
• Primary Examiner(s): ELHILO, EISA B
• Application Number:
  US13/545,030
• Publication Number:
  US 20120276409A1
• Time in Patent Office: 147 Days
• Field of Search: 427/337, 427/404, 427/405, 427/435, 427/436
• US Class Current: 427/337
• CPC Class Codes: C23C 22/02 using non-aqueous solutions
• CPC Class Codes: C23F 11/08 in other liquids
• 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: H05K 2203/122 Organic non-polymeric compounds, e.g. oil, wax, thiol using solvent H05K2203/0783
• 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
• CPC Class Codes: Y10T 428/12556 Organic component

Abstract

A composition for enhancing the corrosion resistance of an article comprising a silver coating deposited on a solderable copper substrate. The composition comprises: a) a multi-functional molecule comprising at least one organic functional group that interacts with and protects copper surfaces and at least one organic functional group that interacts with and protects silver surfaces; b) an alcohol; and c) a surfactant.

Claims

1. A composition for enhancing the corrosion resistance of an article comprising a silver coating deposited on a solderable copper substrate, the composition comprising:

a multi-functional molecule, wherein the multi-functional molecules comprises at least one sulfur-containing organic functional group that interacts with and protects silver surfaces and at least one nitrogen-containing organic functional group that interacts with and protects copper surfaces, wherein the nitrogen-containing functional group comprises one of an amine or aromatic heterocycle;

an alcohol;

a surfactant; and

an alkaline pH adjuster.

2. The composition of claim 1 wherein the nitrogen-containing functional group comprises the amine.

3. The composition of claim 1 wherein the nitrogen-containing functional group comprises one of a primary amine, secondary amine, tertiary amine, or aromatic heterocycle.

4. The composition of claim 1 wherein the nitrogen-containing functional group comprises an azole.

5. The composition of claim 1 wherein the nitrogen-containing functional group comprises a benzimidazole.

6. The composition of claim 1 wherein the sulfur-containing functional group comprises one of a thiol, disulfide, thioether, thioaldehyde, thioketone, or aromatic heterocycle.

7. The composition of claim 3 wherein the sulfur-containing functional group comprises one of a thiol, disulfide, thioether, thioaldehyde, thioketone, or aromatic heterocycle.

8. The composition of claim 5 wherein the sulfur-containing functional group comprises one of a thiol, disulfide, thioether, thioaldehyde, thioketone, or aromatic heterocycle.

9. The composition of claim 1 wherein the sulfur-containing functional group comprises a thiol.

10. The composition of claim 1 wherein the sulfur-containing functional group comprises a disulfide.

11. The composition of claim 1 wherein the multi-functional molecule comprises azole and thiol functional groups.

12. The composition of claim 1 wherein the multi-functional molecule has one of the following structures:

13. The composition of claim 3 wherein the multi-functional molecule has one of the following structures:

14. The composition of claim 5 wherein the multi-functional molecule has one of the following structures:

15. The composition of claim 1 wherein the alcohol is present in a concentration between about 10 mL/L and about 500 mL/L.

16. The composition of claim 1 wherein the surfactant is non-ionic.

17. The composition of claim 1 wherein the multi-functional molecule is present in a concentration between about 0.1 g/L and about 10 g/L.

18. The composition of claim 1 wherein:

the alcohol is present in a concentration between about 10 mL/L and about 500 mL/L;

the surfactant is non-ionic and present in a concentration between about 0.01 g/L and about 2 g/L; and

the multi-functional molecule is present in a concentration between about 0.1 g/L and about 10 g/L.

19. The composition of claim 1 wherein:

the alcohol is present in a concentration between about 10 mL/L and about 500 mL/L;

the surfactant is non-ionic and present in a concentration between about 0.01 g/L and about 2 g/L; and

the multi-functional molecule is present in a concentration between about 0.1 g/L and about 10 g/L.

20. The composition of claim 1 wherein the composition is free of alkali metal hydroxide.

21. An article comprising a silver coating on a copper substrate, with a protective organic film over the silver coating formed by exposing the copper substrate having the silver coating thereon to the anti-corrosion composition of claim 1.