US4474838A
Expired / Lapsed
US
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Electroless direct deposition of gold on metallized ceramics
Assignee: OMI International Corp
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Filing: 1982-12-01
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Granted: 1984-10-02
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Expires: 2002-12-01
Abstract
Abstract Electroless gold plating baths for plating metallized ceramics wherein the bath comprises (a) alkali metal gold cyanide, (b) alkali metal fluoride, and (c) alkali metal hydroxide. The baths may optionally contain a buffering agent and/or ammonium hydroxide and/or an organic chelating agent. The metallized ceramics contain tungsten, molybdenum, electroless nickel, copper and the like. The gold constituent in the alkali metal gold cyanide may be monovalent, trivalent or mixtures thereof. The method of utilizing such electroless or autocatalytic plating baths is also described and claimed.
Inventors
- 👤 Alan A. Halecky
- 👤 Mohamed F. El-Shazly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:52
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/42; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K3/00; H05K3/22; H05K3/24; H05K3/244; H05K3/245
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
68 words
An electroless plating method for plating gold on a non-activated metallized ceramic substrate which comprises immersing said substrate in a gold plating bath which comprises (a) alkali metal gold cyanide, (b) alkali metal fluoride, and (c) alkali metal hydroxide and maintaining the substrate in said bath, without the passage of electric current therethrough, for a period of time sufficient to deposit directly the desired amount of gold thereon.
Claim 2
Dependent Claim
68 words
An electroless plating method for plating gold on a non-activated metallized ceramic substrate which comprises immersing said substrate in a gold plating bath which comprises (a) alkali metal gold cyanide, (b) alkali metal fluoride, and (c) alkali metal hydroxide and maintaining the substrate in said bath, without the passage of electric current therethrough, for a period of time sufficient to deposit directly the desired amount of gold thereon.
Claim 3
Dependent Claim
22 words
The process of claim 1 in which the electroless gold plating bath has a pH within the range of 11 to 14.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein the gold in the alkali metal gold cyanide is trivalent, monovalent or a mixture thereof.
Claim 5
Dependent Claim
27 words
The process of claim 3 wherein the gold is a mixture of trivalent and monovalent gold in which the weight ratio of trivalent gold:monovalent gold is 1:1-3.
Claim 6
Dependent Claim
32 words
The process of claim 1 wherein the electroless gold plating bath contains a buffering agent selected from the group consisting of an alkali metal tartrate, phosphate, citrate, borate, metaborate, and mixtures thereof.
Claim 7
Dependent Claim
14 words
The process of claim 1 wherein the electroless gold plating bath contains ammonium hydroxide.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein the electroless gold plating bath contains an organic chelating agent.
Claim 9
Dependent Claim
62 words
The process of claim 1 wherein the electroless gold plating bath has a pH of from about 12 to 14 and comprising the following: ______________________________________
Component Amount, g/l
______________________________________
(a) alkali metal gold cyanide
1-10
(b) alkali metal fluoride 5-40
(c) alkali metal hydroxide
10-80
(d) chelating agent (when present)
10-40
(e) buffering agent 10-50
(f) ammonium hydroxide (when present)
1-18
______________________________________
Claim 10
Dependent Claim
14 words
The process of claim 3 wherein the alkali metal gold cyanide is potassium auricyanide.
Claim 11
Dependent Claim
13 words
The process of claim 3 wherein the alkali metal cyanide is potassium aurocyanide.
Claim 12
Dependent Claim
15 words
The process of claim 1 wherein the alkali metal fluoride is potassium or sodium fluoride.
Claim 13
Dependent Claim
15 words
The process of claim 1 wherein the alkali metal hydroxide is potassium or sodium hydroxide.
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) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |