US4374876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the immersion deposition of gold
Assignee: OMI International Corp
•
Filing: 1981-06-02
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Granted: 1983-02-22
•
Expires: 2001-06-02
Abstract
Abstract An electroless plating process for depositing gold on substrates, such as metal and metallized substrates, which involves immersing the substrates in an electroless plating bath composed of a trivalent gold complex, an organic carboxylic acid, and/or a mineral acid sufficient in amount so that the pH of the bath will range from about 0.1 to 6.0. The process of utilizing said electroless bath to deposit gold on the aforementioned substrates is also disclosed and claimed.
Inventors
- 👤 Mohamed F. El-Shazly
- 👤 Kenneth D. Baker
- 👤 Yvonne Rymwid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:10
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/42
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
126 words
A process for electroless plating gold on a substrate which comprises immersing such substrate in an electroless gold plating bath which comprises a trivalent gold complex selected from alkali metal auricyanides and alkali metal auric imides in an amount which is at least sufficient to deposit gold on the substrate up to the maximum solubility of the complex in the bath, and at least one of the following ingredients: (a) an organic carboxylic acid, and (b) a mineral acid in amounts sufficient to adjust the pH of the bath to from about 0.1 to 6.0 and maintaining such substrate immersed in said bath, without the passage of electrical current therethrough, for a period of time sufficient to form an immersion deposit of gold on said substrate.
Claim 2
Dependent Claim
126 words
A process for electroless plating gold on a substrate which comprises immersing such substrate in an electroless gold plating bath which comprises a trivalent gold complex selected from alkali metal auricyanides and alkali metal auric imides in an amount which is at least sufficient to deposit gold on the substrate up to the maximum solubility of the complex in the bath, and at least one of the following ingredients: (a) an organic carboxylic acid, and (b) a mineral acid in amounts sufficient to adjust the pH of the bath to from about 0.1 to 6.0 and maintaining such substrate immersed in said bath, without the passage of electrical current therethrough, for a period of time sufficient to form an immersion deposit of gold on said substrate.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein the alkali metal is potassium.
Claim 4
Dependent Claim
31 words
The process of claim 1 wherein the organic carboxylic acid is selected from the group consisting of acetic acid, citric acid, tartaric acid, oxalic acid, ascorbic acid, and aminio carboxylic acids.
Claim 5
Dependent Claim
13 words
The process of claim 3 wherein the organic carboxylic acid is citric acid.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein the mineral acid is selected from the group consisting of hydrochloric acid, sulfuric acid, and phosphoric acid.
Claim 7
Dependent Claim
12 words
The process of claim 5 wherein the mineral acid is hydrochloric acid.
Claim 8
Dependent Claim
27 words
The process of claim 1 wherein the bath additionally contains a catalytic amount of metal ions selected from the group consisting of cobalt, nickel, and iron ions.
Claim 9
Dependent Claim
80 words
The process of claim 7 wherein the electroless gold plating bath has the following composition: ______________________________________
Component Amount g/l
______________________________________
(a) Trivalent gold, as trivalent
0.25-20
gold complex
(b) an organic carboxylic acid
0-50
(c) a mineral acid 0-600 ml/l
(d) cobalt, nickel or iron ions
0-10
______________________________________ wherein at least one of Components (b) and (c) are present in the immersion bath in an amount sufficient to maintain the bath pH in the range of about 0.2 to 4.0.
References Cited (Backward Citations)
US2836515A
Cited
US2995473A
Cited
US3214292A
Cited
US3589916A
Cited
US3598706A
Cited
US3700469A
Cited
US3697296A
Cited
US3993808A
Cited
US3862850A
Cited
US3917885A
Cited
US4168214A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |