Patent US5364460A successfully refreshed from Google Patents.
US5364460A
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Electroless gold plating bath
Assignee: C Uyemura & Co Ltd
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Filing: 1994-03-25
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Granted: 1994-11-15
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Expires: 2014-03-25
Abstract
Abstract To a neutral electroless gold plating bath comprising a gold sulfite, a sulfite, and a reducing agent, there are added an organic phosphonic acid or a salt thereof and an optional stabilizer in the form of a non-ionic surfactant or non-ionic polymer. A gold plating film having an aesthetic lemon yellow color tone and susceptible to bonding deposits on an article from the bath without attacking the base material of the article and without plating spread.
Inventors
- 👤 Keizin Morimoto
- 👤 Masanobu Tsujimoto
- 👤 Tomomi Yaji
- 👤 Tooru Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:20
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/42; C23C18/44; H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/244
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
50 words
An electroless gold plating bath comprising a gold sulfite, a sulfite as a complexing agent for gold ion, at least one reducing agent selected from the group consisting of a hydrazine, ascorbic acid, a salt of ascorbic acid, trimethylamineborane, and dimethylamineborane, and an organic phosphonic acid or a salt thereof.
Claim 2
Dependent Claim
50 words
An electroless gold plating bath comprising a gold sulfite, a sulfite as a complexing agent for gold ion, at least one reducing agent selected from the group consisting of a hydrazine, ascorbic acid, a salt of ascorbic acid, trimethylamineborane, and dimethylamineborane, and an organic phosphonic acid or a salt thereof.
Claim 3
Dependent Claim
63 words
A bath according to claim 1 wherein the amount of the gold sulfite is 1 to 20 grams/liter, the amount of the sulfite as the complexing agent for gold ion is 5 to 150 grams/liter, the amount of the reducing agent is 1 to 100 grams/liter, and the amount of the organic phosphonic acid or the salt thereof is 1 to 200 grams/liter.
Claim 4
Dependent Claim
19 words
A bath according to claim 1 wherein the organic phosphonic acid is aminotri(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid or ethylenediaminetetra(methylenephosphonic acid).
Claim 5
Dependent Claim
12 words
A bath according to claim 1 which further contains a nitrogenous compound.
Claim 6
Dependent Claim
24 words
A bath according to claim 4 wherein the nitrogenous compound is selected from the group consisting of p-methylaminophenol, aminophenol, metanilic acid and anthranilic acid.
Claim 7
Dependent Claim
17 words
A bath according to claim 4 wherein the amount of nitrogenous compound is 0.01 to 100 grams/liter.
Claim 8
Dependent Claim
19 words
A bath according to claim 1 which further contains a thiosulfate in an amount of 0.1 to 30 grams/liter.
Claim 9
Dependent Claim
24 words
A bath according to claim 1 which further contains an oxycarboxylic acid or a derivative thereof in an amount of 5 to 100 grams/liter.
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) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |