US4279715A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Etching of aluminum capacitor foil
Assignee: UNITED CHEMI-CON MANUFACTURING Inc
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Filing: 1980-09-15
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Granted: 1981-07-21
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Expires: 2000-09-15
Abstract
Abstract Aluminum electrolytic capacitor foil is etched in a bath containing 1.0 to 1.8 M hydrochloric acid, 0.25 to 0.5 M aluminum chloride, 0.2 to 1.0 M phosphoric acid, and 1.0 to 2.0 M chromium trioxide while subjected to the action of alternating current at 35 DEG to 55 DEG C.
Inventors
- 👤 Mulk A. Arora
- 👤 John J. Randall, Jr.
- 👤 Walter J. Bernard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:56
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/04; H01G9/048; H01G9/055; C; C25; C25F; C25F3/00; C25F3/02; C25F3/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
46 words
A process for etching aluminum electrolytic capacitor foil comprising electrolytically etching said foil using alternating current in a bath containing 1.0 to 1.8 M hydrochloric acid, 0.25 to 0.5 M hydrated aluminum trichloride, 0.2 to 1.0 M phosphoric acid, and 1.0 to 2.0 M chromium trioxide.
Claim 2
Dependent Claim
46 words
A process for etching aluminum electrolytic capacitor foil comprising electrolytically etching said foil using alternating current in a bath containing 1.0 to 1.8 M hydrochloric acid, 0.25 to 0.5 M hydrated aluminum trichloride, 0.2 to 1.0 M phosphoric acid, and 1.0 to 2.0 M chromium trioxide.
Claim 3
Dependent Claim
17 words
A process according to claim 1 wherein the temperature of said bath is 35° to 55° C.
Claim 4
Dependent Claim
12 words
A process according to claim 2 wherein said temperature is 45° C.
Claim 5
Dependent Claim
18 words
A process according to claim 1 wherein the anodic current density is 2.0 to 3.5 amps/in 2 .
Claim 6
Dependent Claim
27 words
A process according to claim 1 wherein said bath contains 1.4 M hydrochloric acid, 0.4 M aluminum trichloride, 0.7 M phosphoric acid, and 1.4 M chromium trioxide.
Claim 7
Dependent Claim
18 words
A process according to claim 1 wherein the frequency of said alternating current is 30 to 60 Hz.
Claim 8
Dependent Claim
14 words
A process according to claim 6 wherein said frequency is 50 to 60 Hz.
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) | 1984-07-20 | 1985-01-19 | 1985-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-20 | 1989-01-19 | 1989-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-20 | 1993-01-19 | 1993-07-21 | $7700.00 | Window Closed / Lapsed |