Patent US4190489A successfully refreshed from Google Patents.
US4190489A
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Gold etchant composition and method
Assignee: Eastman Kodak Co
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Filing: 1978-09-21
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Granted: 1980-02-26
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Expires: 1998-09-21
Abstract
Abstract A composition and method for etching gold, particularly gold layers on ceramic substrates, in which the gold is contacted at room temperature by an aqueous solution of alkali metal bromide and bromine. The composition is relatively safe and easy to handle and rapidly etches gold.
Inventors
- 👤 Surinder K. Bahl
- 👤 Gale L. Leach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:41
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/30; H; H10; H10P; H10P50/00; H10P50/60; H10P50/66; H10P50/663; H10P50/667
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
46 words
A gold etchant composition consisting essentially of an aqueous solution of from 3.3% to 37.5% alkali metal bromide, 2.2% to 12.5% bromine, and balance water, all percentages by weight, said etchant being capable of etching a gold layer at the rate of at least 50 A/sec.
Claim 2
Dependent Claim
46 words
A gold etchant composition consisting essentially of an aqueous solution of from 3.3% to 37.5% alkali metal bromide, 2.2% to 12.5% bromine, and balance water, all percentages by weight, said etchant being capable of etching a gold layer at the rate of at least 50 A/sec.
Claim 3
Dependent Claim
20 words
The composition of claim 1 where the mole ratio of alkali metal bromide to bromine is from 1:1 to 2:1.
Claim 4
Dependent Claim
13 words
The composition of claim 2 where the alkali metal bromide is potassium bromide.
Claim 5
Independent Claim
43 words
A method of etching a gold layer from a substrate material comprising the steps of contacting said gold layer with an aqueous solution comprising a mixture of an alkali metal bromide and bromine for a time sufficient to etch away said gold layer.
Claim 6
Independent Claim
43 words
A method of etching a gold layer from a substrate material comprising the steps of contacting said gold layer with an aqueous solution comprising a mixture of an alkali metal bromide and bromine for a time sufficient to etch away said gold layer.
Claim 7
Dependent Claim
20 words
The method of claim 4 where the mole ratio of alkali metal bromide to bromine is from 1:1 to 2:1.
Claim 8
Dependent Claim
13 words
The method of claim 5 where the alkali metal bromide is potassium bromide.
Claim 9
Dependent Claim
13 words
The method of claim 6 where the contacting step occurs at room temperature.
Claim 10
Dependent Claim
38 words
The method of claim 7 where the gold layer is on a ceramic substrate and the time of contact is 2 to 40 seconds depending on the dilution of the bromide-bromine solution and thickness of the gold film.
References Cited (Backward Citations)
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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) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |