Patent US4376686A successfully refreshed from Google Patents.
US4376686A
Expired / Lapsed
US
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AC Etching of aluminum capacitor foil
Assignee: Sprague Electric Co
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Filing: 1981-11-16
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Granted: 1983-03-15
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Expires: 2001-11-16
Abstract
Abstract Aluminum capacitor foil is etched using AC current and an etchant bath comprising 0.8 to 1.5 M hydrochloric acid, 0.4 to 0.5 M aluminum chloride, 0.04 to 0.3 M nitric acid, and 0.05 to 0.2 M tartaric acid. The frequency of the alternating current is 12 to 20 Hz, and the bath temperature is 30 DEG to 40 DEG C.
Inventors
- 👤 Mulk R. Arora
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:16
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: 5
Claim 1
Independent Claim
84 words
A process for the etching of aluminum capacitor foil comprising passing the foil through an electrolytic bath under the influence of alternating current, said bath consisting essentially of 0.8 to 1.5 moles/liter of hydrochloric acid, 0.4 to 0.5 moles/liter aluminum chloride, 0.04 to 0.3 moles/liter of nitric acid, and 0.05 to 0.2 moles/liter of tartaric acid, said alternating current having a frequency of 12 to 20 Hz, at a temperature of about 30° to 40° C. rendering said foil more amenable to subsequent processing.
Claim 2
Dependent Claim
84 words
A process for the etching of aluminum capacitor foil comprising passing the foil through an electrolytic bath under the influence of alternating current, said bath consisting essentially of 0.8 to 1.5 moles/liter of hydrochloric acid, 0.4 to 0.5 moles/liter aluminum chloride, 0.04 to 0.3 moles/liter of nitric acid, and 0.05 to 0.2 moles/liter of tartaric acid, said alternating current having a frequency of 12 to 20 Hz, at a temperature of about 30° to 40° C. rendering said foil more amenable to subsequent processing.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein said frequency is 13 to 15 Hz.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein said temperature is 33° to 36° C.
Claim 5
Dependent Claim
41 words
A process according to claim 1 wherein the concentration of said hydrochloric acid is 1 to 1.4 moles/liter, the concentration of said nitric acid is 0.1 to 0.3 moles/liter, and the concentration of said tartaric acid is 0.05 to 0.15 moles/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) | 1986-03-14 | 1986-09-13 | 1987-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-14 | 1990-09-13 | 1991-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-14 | 1994-09-13 | 1995-03-15 | $7700.00 | Window Closed / Lapsed |