US4655833A
Expired / Lapsed
US
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Electroless copper plating bath and improved stability
Assignee: International Business Machines Corp
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Filing: 1985-10-09
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Granted: 1987-04-07
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Expires: 2005-10-09
Abstract
Abstract An electroless copper plating bath having improved stability which contains a cationic polymer from acrylamide and/or methacrylamide. The plating bath also contains a cupric ion source, a reducing agent for the cupric ion source, and a complexing agent for the cupric ion.
Inventors
- 👤 William J. Amelio
- 👤 Peter G. Bartolotta
- 👤 Voya Markovich
- 👤 Ralph E. Parsons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:45
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/38; C23C18/40
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
93 words
An electroless copper plating bath of improved stability which comprises: A. cupric ion source in an amount of about 3 to about 15 grams per liter calculated as cupric sulfate; B. a reducing agent for the cupric ion source in an amount of about 0.7 to about 7 grams per liter; C. a complexing agent for the cupric ion in an amount of about 20 to 50 grams per liter; and D. about 1 part per billion to about 1,000 parts per billion of a cationic polymer from acrylamide or methacrylamide, or both.
Claim 2
Dependent Claim
93 words
An electroless copper plating bath of improved stability which comprises: A. cupric ion source in an amount of about 3 to about 15 grams per liter calculated as cupric sulfate; B. a reducing agent for the cupric ion source in an amount of about 0.7 to about 7 grams per liter; C. a complexing agent for the cupric ion in an amount of about 20 to 50 grams per liter; and D. about 1 part per billion to about 1,000 parts per billion of a cationic polymer from acrylamide or methacrylamide, or both.
Claim 3
Dependent Claim
25 words
The electroless copper plating bath of claim 1 which contains about 1 part per billion to about 500 parts per billion of said cationic polymer.
Claim 4
Dependent Claim
14 words
The electroless copper plating bath of claim 1 which contains an anionic surface-active agent.
Claim 5
Dependent Claim
27 words
The electroless copper plating bath of claim 3 wherein said anionic surface-active agent is present in an amount from about 0.02 to about 0.3 grams per liter.
Claim 6
Dependent Claim
17 words
The electroless copper plating bath of claim 1 having a pH of about 11.8 to about 12.5.
Claim 7
Dependent Claim
18 words
The electroless copper plating bath of claim 1 which has a pH of about 11.9 to about 12.
Claim 8
Dependent Claim
23 words
The electroless copper plating bath of claim 1 which also contains about 10 to about 25 milligrams per liter of a cyanide ion.
Claim 9
Dependent Claim
31 words
The electroless copper plating bath of claim 1 wherein the cupric ion source is present in an amount from about 8 to about 12 grams per liter calculated as cupric sulfate.
Claim 10
Dependent Claim
16 words
The electroless copper plating bath of claim 1 wherein the cupric ion source is cupric sulfate.
Claim 11
Dependent Claim
26 words
The electroless copper plating bath of claim 1 wherein the reducing agent is present in an amount from about 3 to about 4 milliliters per liter.
Claim 12
Dependent Claim
14 words
The electroless copper plating bath of claim 1 wherein said reducing agent is formaldehyde.
Claim 13
Dependent Claim
20 words
The electroless copper plating bath of claim 1 wherein said complexing agent is ethylene diamine tetraacetic acid or salt thereof.
Claim 14
Dependent Claim
17 words
The electroless copper plating bath of claim 1 wherein said cationic polymer is a multifunctional cationic polymer.
Claim 15
Dependent Claim
21 words
The electroless copper plating bath of claim 1 wherein said cationic polymer is a copolymer of acrylamide and ammonium quaternary compound.
Claim 16
Dependent Claim
20 words
A method for coating a substrate which comprises contacting the substrate with an electroless copper plating bath of claim 1.
Claim 17
Dependent Claim
24 words
The method of claim 15 wherein said electroless copper plating bath is maintained at a temperature of about 70° C. to about 80° C.
Claim 18
Dependent Claim
21 words
The method of claim 15 wherein the temperature of the plating bath is maintained between about 70° C. and 75° C.
Claim 19
Dependent Claim
138 words
The electroless copper plating bath of claim 1 which consists essentially of a. cupric ion source in an amount of about 3 to about 15 grams per liter calculated as cupric sulfate; b. a reducing agent for the cupric ion source in an amount of about 0.7 to about 7 grams per liter; c. ethylene diamine tetraacetic acid or salt thereof in an amount of about 20 to 50 grams per liter; d. about 1 part per billion to about 1,000 parts per billion of a cationic polymer from acrylamide or methacrylamide, or both. e. anionic surface-active agent in an amount of from about 0.02 to about 0.3 grams per liter; and f. about 10 to about 25 miligrams per liter of a cyanide ion, and wherein the pH of said bath is about 11.8 to about 12.5.
Claim 20
Dependent Claim
67 words
The electroless copper plating bath of claim 18 which contains about 1 part per billion to about 500 parts per billion of said cationic polymer; wherein the cupric ion source is present in an amount from about 8 to about 12 grams per liter calculated as cupric sulfate; and wherein the reducing agent is present in an amount from about 3 to about 4 milliliters per liter.
Claim 21
Dependent Claim
31 words
The electroless copper plating bath of claim 18 wherein said cationic polymer is a copolymer of acrylamide and ammonium quaternary compound, and said anionic surface-active agent is an organic phosphate ester.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |