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Patent US4337091A successfully refreshed from Google Patents.
US4337091A
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Electroless gold plating
Assignee: OMI International Corp
•
Filing: 1981-03-23
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Granted: 1982-06-29
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Expires: 2001-03-23
Abstract
Abstract Improved electroless or autocatalytic gold plating baths wherein the gold ingredient is a water soluble trivalent gold component selected from an alkali metal auricyanide, an alkali metal aurihydroxide, and an alkali metal aurate. The bath contains an amino borane, an alkali metal borohydride, or an alkali metal cyanoborohydride as the reducing agent; an alkaline agent such as an alkali metal hydroxide; and an alkaline buffering agent. Optionally, the bath may contain added alkali metal cyanide. The method of utilizing such electroless or autocatalytic plating bath for depositing gold on metallic substrates such as gold, copper, copper alloys, electroless copper, electroless nickel, nickel, nickel alloys, etc. and on a non-metallic substrates is also described and claimed.
Inventors
- 👤 Mohamed F. El-Shazly
- 👤 Kenneth D. Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:47
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/42; C23C18/44
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
100 words
An aqueous electroless gold plating bath comprising a water-soluble, trivalent gold component selected from the group consisting of alkali metal auricyanides, alkali metal aurates and alkali metal aurihydroxides and a reducing agent selected from the group consisting of alkylamino boranes, alkali metal borohydrides and alkali metal cyanoborohydrides, the gold component being present in an amount at least sufficient to deposit gold on the substrate to be plated and the reducing agent being present in an amount at least sufficient to reduce the gold in the bath, which plating bath has a pH within the range of about 10 to 13.
Claim 2
Dependent Claim
100 words
An aqueous electroless gold plating bath comprising a water-soluble, trivalent gold component selected from the group consisting of alkali metal auricyanides, alkali metal aurates and alkali metal aurihydroxides and a reducing agent selected from the group consisting of alkylamino boranes, alkali metal borohydrides and alkali metal cyanoborohydrides, the gold component being present in an amount at least sufficient to deposit gold on the substrate to be plated and the reducing agent being present in an amount at least sufficient to reduce the gold in the bath, which plating bath has a pH within the range of about 10 to 13.
Claim 3
Dependent Claim
33 words
The electrodes gold plating bath of claim 1, wherein there is also included an alkaline agent and an alkaline buffering agent in amounts sufficient to maintain the bath pH within the specified ranges.
Claim 4
Dependent Claim
21 words
The electrodes gold plating bath of claim 2, wherein the pH is maintained within the range of about 11 to 13.
Claim 5
Dependent Claim
16 words
The electroless gold plating bath of claim 2, wherein the reducing agent is a dialkylamine borane.
Claim 6
Dependent Claim
15 words
The electroless gold plating bath of claim 4, wherein the dialkylamino borane is dimethylamino borane.
Claim 7
Dependent Claim
17 words
The electroless gold plating bath of claim 1, wherein the reducing agent is an alkali metal borohydride.
Claim 8
Dependent Claim
16 words
The electrodes gold plating bath of claim 6, wherein the alkali metal borohydride is potassium borohydride.
Claim 9
Dependent Claim
17 words
The electroless gold plating bath of claim 1, wherein said reducing agent is an alkali metal cyanoborohydride.
Claim 10
Dependent Claim
16 words
The electroless gold plating bath of claim 8, wherein the alkali metal cyanoborohydride is potassium cyanoborohydride.
Claim 11
Dependent Claim
18 words
The electroless gold plating bath of claim 2, wherein said alkaline agent is sodium hydroxide or potassium hydroxide.
Claim 12
Dependent Claim
30 words
The electrodes gold plating bath of claim 2, wherein said alkaline buffering agent is selected from the group consisting of alkali metal phosphates, citrates, tartrates, borates, metaborates, and mixtures thereof.
Claim 13
Dependent Claim
25 words
The electroless gold plating bath of claim 1, wherein from 1 to 30 g/l of an alkali metal cyanide is added as an additional ingredient.
Claim 14
Dependent Claim
18 words
The electroless gold plating bath of claim 1, wherein said trivalent gold component is an alkali metal auricyanide.
Claim 15
Dependent Claim
16 words
The electroless gold plating bath of claim 13, wherein the alkali metal auricyanide is potassium auricyanide.
Claim 16
Dependent Claim
18 words
The electroless gold plating bath of claim 1, wherein said trivalent gold component is an alkali metal aurate.
Claim 17
Dependent Claim
16 words
The electroless gold plating bath of claim 15, wherein the alkali metal aurate is potassium aurate.
Claim 18
Dependent Claim
18 words
The electroless gold plating bath of claim 1, wherein the trivalent gold component is an alkali metal aurihydroxide.
Claim 19
Dependent Claim
84 words
An aqueous electroless gold plating bath having a pH within the range of about 10 to 13 and comprising the following: ______________________________________
Component Amount - g/l
______________________________________
(a) Trivalent gold, as an
0.5 to 6.0
alkali metal auricyanide,
aurate or aurihydroxide
(b) an alkali metal hydroxide
10 to 90
(c) an alkali metal buffering
15 to 40
salt
(d) an amino borane, an alkali
1 to 6
metal borohydride, or an
alkali metal cyanoboro-
hydride
(e) an alkali metal cyanide
1 to 30
______________________________________
Claim 20
Dependent Claim
84 words
An aqueous electroless gold plating bath having a pH within the range of about 10 to 13 and comprising the following: ______________________________________
Component Amount - g/l
______________________________________
(a) Trivalent gold, as an
0.5 to 6.0
alkali metal auricyanide,
aurate or aurihydroxide
(b) an alkali metal hydroxide
10 to 90
(c) an alkali metal buffering
15 to 40
salt
(d) an amino borane, an alkali
1 to 6
metal borohydride, or an
alkali metal cyanoboro-
hydride
(e) an alkali metal cyanide
1 to 30
______________________________________
Claim 21
Dependent Claim
16 words
The electroless gold plating bath of claim 18, wherein the alkali metal is sodium or potassium.
Claim 22
Dependent Claim
14 words
The electroless gold plating bath of claim 19, wherein the alkali metal is potassium.
Claim 23
Dependent Claim
35 words
The electroless gold plating bath of claim 18, wherein Component (a) is potassium auricyanide; Component (b) is potassium hydroxide; Component (c) is tripotassium citrate; Component (d) is diemethylamino borane; and Component (e) is potassium cyanide.
Claim 24
Dependent Claim
63 words
An electroless plating method for plating gold on a substrate which comprises immersing said substrate in the gold plating bath of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or 21 and maintaining the substrate in said bath for a period sufficient to deposit the desired amount of gold thereon.
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) | 1985-06-28 | 1985-12-28 | 1986-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-28 | 1989-12-28 | 1990-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-28 | 1993-12-28 | 1994-06-29 | $7700.00 | Window Closed / Lapsed |