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US4582574A
Expired / Lapsed
US
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Preparation of capacitor electrodes
Assignee: UNITED CHEMI-CON MANUFACTURING Inc
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Filing: 1985-08-15
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Granted: 1986-04-15
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Expires: 2005-08-15
Abstract
Abstract Aluminum capacitor foil which has been etched for low-voltage applications is rendered usable in intermediate to high voltage capacitors by anodizing the foil in two-stages; first a low voltage stage in an adipate electrolyte and then a higher voltage stage in a borate electrolyte. The fine etch structure of the low-voltage etch is thereby not plugged in the second, higher voltage formation stage, whereby the foil is suitable for intermediate to high-voltage capacitor use.
Inventors
- 👤 Trung H. Nguyen
- 👤 Allan B. McPherson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:45
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/0029; H01G9/0032; C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
A process for the preparation of capacitor electrodes of aluminum foil which has a fine etch structure as a result of having been etched for low-voltage use, said process comprising anodizing said foil at a low voltage in a first stage electrolyte comprising an adipate solution, rinsing said foil of said first electrolyte, and then anodizing said foil to a higher voltage in a second anodizing stage using a borate formation electrolyte, said fine etch structure on said foil is thereby not plugged, whereby said foil is made suitable for higher voltage capacitor use.
Claim 2
Dependent Claim
94 words
A process for the preparation of capacitor electrodes of aluminum foil which has a fine etch structure as a result of having been etched for low-voltage use, said process comprising anodizing said foil at a low voltage in a first stage electrolyte comprising an adipate solution, rinsing said foil of said first electrolyte, and then anodizing said foil to a higher voltage in a second anodizing stage using a borate formation electrolyte, said fine etch structure on said foil is thereby not plugged, whereby said foil is made suitable for higher voltage capacitor use.
Claim 3
Dependent Claim
17 words
A process according to claim 1 wherein said adipate solution is a 0.5 to 12% adipate solution.
Claim 4
Dependent Claim
12 words
A process according to claim 2 wherein said adipate is diammonium adipate.
Claim 5
Dependent Claim
16 words
A process according to claim 3 wherein said adipate solution is a 4.5% diammonium adipate solution.
Claim 6
Dependent Claim
17 words
A process according to claim 1 wherein said borate solution is a 5 to 10% borate solution.
Claim 7
Dependent Claim
16 words
A process according to claim 5 wherein said borate solution is a 10% boric acid solution.
Claim 8
Dependent Claim
31 words
A process according to claim 1 wherein each of said adipate and said borate anodizations is carried out at a temperature between 85° C. and the boiling point of said solution.
Claim 9
Dependent Claim
13 words
A process according to claim 7 wherein each anodization temperature is 90° C.
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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |