US4213835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for electrolytically etching of a recrystallized aluminum foil
Assignee: Siemens AG
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Filing: 1979-01-12
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Granted: 1980-07-22
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Expires: 1999-01-12
Abstract
Abstract A method of etching a recrystallized aluminum foil which utilizes potentiostatic etching to roughen the foil to obtain a particularly high roughening factor. The etching preferably occurs in two stages in which the etching current density of the first stage is above the current density which creates an undesired pitting of the aluminum and a second stage which utilizes an etching current density which is below the density which creates pitting of the aluminum.
Inventors
- 👤 Horst Fickelscher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:14
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: 6
Claim 1
Independent Claim
111 words
A method for electrolytically etching of a recrystallized aluminum foil comprising the steps of providing an etching bath with suitable electrode geometry for etching the foil approximately quasipotentiostatic according to the current density being attained when a constant anode potential is applied, positioning the foil in the bath, and potentiostatically etching the foil with a temporally constant anode potential, the step of etching including applying an anode potential for creating a current density above the current density for creating pitting of the aluminum during a first etching stage and in a following second etching stage reducing the anode potential to create a current density below the density at which pitting occurs.
Claim 2
Independent Claim
111 words
A method for electrolytically etching of a recrystallized aluminum foil comprising the steps of providing an etching bath with suitable electrode geometry for etching the foil approximately quasipotentiostatic according to the current density being attained when a constant anode potential is applied, positioning the foil in the bath, and potentiostatically etching the foil with a temporally constant anode potential, the step of etching including applying an anode potential for creating a current density above the current density for creating pitting of the aluminum during a first etching stage and in a following second etching stage reducing the anode potential to create a current density below the density at which pitting occurs.
Claim 3
Dependent Claim
13 words
A method according to claim 1, wherein the etching bath contains chloride ions.
Claim 4
Independent Claim
86 words
A method for electrolytically etching of a recrystallized aluminum foil comprising the steps of providing an etching bath, positioning the foil in the bath, and potentiostatically etching the foil with a temporally constant anode potential, the step of etching comprising performing a first etching stage with an etching current density which is above the current density for creating pitting in the aluminum and then performing a second etching stage wherein the etching current density is maintained below said current density for creating pitting in the aluminum.
Claim 5
Independent Claim
86 words
A method for electrolytically etching of a recrystallized aluminum foil comprising the steps of providing an etching bath, positioning the foil in the bath, and potentiostatically etching the foil with a temporally constant anode potential, the step of etching comprising performing a first etching stage with an etching current density which is above the current density for creating pitting in the aluminum and then performing a second etching stage wherein the etching current density is maintained below said current density for creating pitting in the aluminum.
Claim 6
Dependent Claim
13 words
A method according to claim 3, wherein the etching bath contains chloride ions.
References Cited (Backward Citations)
GB970572A
Cited
FR1592815A
Cited
US3876479A
Cited
JPS518132A
Cited
US3980539A
Cited
US3935080A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-22 | 1984-01-21 | 1984-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-22 | 1988-01-21 | 1988-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-22 | 1992-01-21 | 1992-07-22 | $7700.00 | Window Closed / Lapsed |