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US4087367A
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Preferential etchant for aluminium oxide
Assignee: US Philips Corp
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Filing: 1975-10-20
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Granted: 1978-05-02
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Expires: 1995-10-20
Abstract
Abstract A method of etching aluminium oxide and/or cleaning aluminium surfaces with an etchant consisting of a solution of a fluoride in an organic solvent, which solution is substantially free from hydrofluoric acid and unbound water.
Inventors
- 👤 Jean-Pierre Rioult
- 👤 Raymond Fabien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:34
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6314; H10W; H10W20/00; H10W20/01
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
32 words
An etchant for preferentially removing aluminium oxide from bodies, consisting essentially of a non-aqueous solution of ammonium fluoride in organic solvent, the solution being essentially free of hydrofluoric acid and unbound water.
Claim 2
Dependent Claim
32 words
An etchant for preferentially removing aluminium oxide from bodies, consisting essentially of a non-aqueous solution of ammonium fluoride in organic solvent, the solution being essentially free of hydrofluoric acid and unbound water.
Claim 3
Dependent Claim
14 words
An etchant as defined in claim 1 wherein the organic solvent is ethylene glycol.
Claim 4
Dependent Claim
13 words
An etchant as defined in claim 1 wherein the organic solvent is glycerol.
Claim 5
Dependent Claim
15 words
An etchant as defined in claim 1 wherein the organic solvent is glacial acetic acid.
Claim 6
Dependent Claim
24 words
An etchant as defined in claim 4 wherein the solution contains no more than 30G of ammonium fluoride per liter of glacial acetic acid.
Claim 7
Dependent Claim
23 words
An etchant as defined in claim 5 wherein the solution contains at least 10g of ammonium fluoride per liter of glacial acetic acid.
Claim 8
Independent Claim
46 words
A method of preferentially removing aluminium oxide from a surface of a body comprising the step of etching the surface of the body with a non-aqueous solution consisting of an ammonium fluoride in organic solvent, the solution being essentially free of hydrofluoric acid and unbound water.
Claim 9
Independent Claim
46 words
A method of preferentially removing aluminium oxide from a surface of a body comprising the step of etching the surface of the body with a non-aqueous solution consisting of an ammonium fluoride in organic solvent, the solution being essentially free of hydrofluoric acid and unbound water.
Claim 10
Dependent Claim
14 words
A method as defined in claim 7 wherein the organic solvent is ethylene glycol.
Claim 11
Dependent Claim
13 words
A method as defined in claim 7 wherein the organic solvent is glycerol.
Claim 12
Dependent Claim
15 words
A method as defined in claim 7 wherein the organic solvent is glacial acetic acid.
Claim 13
Dependent Claim
24 words
A method as defined in claim 10 wherein the solution contains no more than 30g of ammonium fluoride per liter of glacial acetic acid.
Claim 14
Dependent Claim
23 words
A method as defined in claim 11 wherein the solution contains at least 10g of ammonium fluoride per liter of glacial acetic acid.
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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) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |