Patent US4818286A successfully refreshed from Google Patents.
US4818286A
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Electroless copper plating bath
Assignee: International Business Machines Corp
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Filing: 1988-03-08
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Granted: 1989-04-04
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Expires: 2008-03-08
Abstract
Abstract An electroless copper plating bath contains copper sulfate, EDTA, DMAB and triethanolamine and is adjusted to a pH in the range between approximately 8 and 9. The addition of cyanide ions alone or preferably with a sulfur compound such as thiodipropionic acid or a nitrogen compound such as 1,10 phenanthroline provided bright copper deposits. The use of an electroless plating bath operating at a low pH permits electroless plating of alkali sensitive substrates.
Inventors
- 👤 Rangarajan Jagannathan
- 👤 Mahadevaiyer Krishnan
- 👤 Gregory P. Wandy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:07
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/38; C23C18/40
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
106 words
An electroless copper plating bath for providing a predominately copper deposit which is firmly adherent to various substrates, said bath being devoid of formaldehyde comprising: 2 to 8 grams per liter of copper sulfate 20 to 40 grams per liter of EDTA 3 to 5 grams per liter of amine borane, and 50 to 100 milliliters per liter of alkanolamine, wherein said EDTA is selected from the group consisting of an alkali metal EDTA, said amine borane is selected from the group consisting of DMAB, morpholineamineborane, t-butylamineborane and isopropylamineborane and alkanolimine is selected from the group consisting of triethanolamine, alkyl groups in the alkanolamine, including mixtures.
Claim 2
Dependent Claim
106 words
An electroless copper plating bath for providing a predominately copper deposit which is firmly adherent to various substrates, said bath being devoid of formaldehyde comprising: 2 to 8 grams per liter of copper sulfate 20 to 40 grams per liter of EDTA 3 to 5 grams per liter of amine borane, and 50 to 100 milliliters per liter of alkanolamine, wherein said EDTA is selected from the group consisting of an alkali metal EDTA, said amine borane is selected from the group consisting of DMAB, morpholineamineborane, t-butylamineborane and isopropylamineborane and alkanolimine is selected from the group consisting of triethanolamine, alkyl groups in the alkanolamine, including mixtures.
Claim 3
Dependent Claim
21 words
An electroless copper plating bath as set forth in claim 1, further comprising 1.6 to 2.0 micromoles per liter of cyanide.
Claim 4
Dependent Claim
16 words
An electroless copper plating bath as set forth in claim 2, said cyanide being sodium cyanide.
Claim 5
Dependent Claim
20 words
An electroless copper plating bath as set forth in claim 2, further comprising 22 micrograms per liter of 1,10 phenanthroline.
Claim 6
Dependent Claim
25 words
An electroless copper plating bath as set forth in claim 4, wherein the pH of said bath is in the range between 8.0 and 9.5.
Claim 7
Dependent Claim
25 words
An electroless copper plating bath as set forth in claim 4, wherein the pH of said bath is in the range between 8.0 and 9.0.
Claim 8
Dependent Claim
23 words
An electroless copper plating bath as set forth in claim 4, wherein said bath is operated at a temperature of approximately 60° centigrade.
Claim 9
Dependent Claim
18 words
An electroless copper plating bath as set forth in claim 4, wherein said EDTA is a disodium salt.
Claim 10
Dependent Claim
16 words
An electroless copper plating bath as set forth in claim 4, wherein said alkanolamine is triethanolamine.
Claim 11
Dependent Claim
19 words
An electroless copper plating bath as set forth in claim 9, wherein said triethanolamine has a pH of 8.7.
Claim 12
Dependent Claim
25 words
An electroless copper plating bath as set forth in claim 1, wherein the pH of said bath is in the range between 8.0 and 9.5.
Claim 13
Dependent Claim
25 words
An electroless copper plating bath as set forth in claim 1, wherein the pH of said bath is in the range between 8.0 and 9.0.
Claim 14
Dependent Claim
23 words
An electroless copper plating bath as set forth in claim 1, wherein said bath is operated at a temperature of approximately 60° centigrade.
Claim 15
Dependent Claim
18 words
An electroless copper plating bath as set forth in claim 1, wherein said EDTA is a disodium salt.
Claim 16
Dependent Claim
16 words
An electroless copper plating bath as set forth in claim 1, wherein said alkanolamine is triethanolamine.
Claim 17
Dependent Claim
19 words
An electroless copper plating bath as set forth in claim 15, wherein said triethanolamine has a pH of 8.7.
Claim 18
Dependent Claim
19 words
An electroless copper plating bath as set forth in claim 1, wherein said substrate is an alkali sensitive substrate.
Claim 19
Dependent Claim
18 words
An electroless copper plating bath as set forth in claim 17, wherein said alkali sensitive substrate is polyimide.
Claim 20
Dependent Claim
19 words
An electroless copper plating bath as set forth in claim 17, wherein said alkali sensitive substrate includes positive photoresist.
Claim 21
Dependent Claim
18 words
An electroless copper plating bath as set forth in claim 1, wherein said substrate is an epoxy substrate.
Claim 22
Dependent Claim
20 words
An electroless copper plating bath as set forth in claim 20, wherein said epoxy substrate is activated with Pd/Sn colloid.
Claim 23
Dependent Claim
15 words
An electroless copper plating bath as set forth in claim 2, further comprising thiodipropionic acid.
Claim 24
Dependent Claim
62 words
An electroless copper plating bath as set forth in claim 1, wherein said copper sulfate is present in an amount of 4 grams per liter, said EDTA is present in an amount of 20 grams per liter, said DMAB is present in an amount of 4 grams per liter and said triethanolamine is present in an amount of 50 milliliters per liter.
Claim 25
Dependent Claim
36 words
An electroless copper plating bath as set forth in claim 23, further comprising 128 micrograms per liter of sodium cyanide, 22 micrograms per liter of 1,10 phenanthroline and 10 milligrams per liter of sodium lauryl sulfate.
Claim 26
Dependent Claim
28 words
An electroless copper plating bath as set forth in claim 1, wherein said EDTA is a disodium salt, said amine borane is DMAB, and said alkanolamine is triethanolamine.
Claim 27
Dependent Claim
38 words
An electroless copper plating bath as set forth in claim 25, further comprising 1.6 to 2.0 micromoles per liter of sodium cyanide, 22 micrograms per liter of 1,10 phenanthroline and 10 milligrams per liter of sodium lauryl sulfate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |