US3944450A
Expired / Lapsed
US
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Method of producing tantalum dry-electrolytic capacitors
Assignee: Siemens AG
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Filing: 1973-11-15
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Granted: 1976-03-16
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Expires: 1993-11-15
Abstract
Abstract A method of producing a tantalum dry-electrolytic capacitor which comprises a sintered tantalum anode having applied thereto, by a forming process, an dielectric oxide layer and a semiconducting manganese dioxide cathode layer, with the latter being coated with a graphite layer serving as current supply, in which, after formation of the manganese dioxide layer, a thin layer of manganese dioxide is removed from the surface thereof by chemical treatment, following which the cathode is coated with the desired graphite layer.
Inventors
- 👤 Werner Schnabel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:26
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/15
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
79 words
A method of producing a tantalum dry-electrolytic capacitor comprising a sintered tantalum anode, oxidized to form a dielectric layer, and a semiconducting manganese dioxide cathode layer which is coated with a graphite layer serving as current supply, characterized in that after the formation of the manganese dioxide layer a thin layer of manganese dioxide is removed from the surface thereof by chemical treatment in an acetic acid-hydrogen peroxide bath, following which the cathode is coated with said graphite layer.
Claim 2
Independent Claim
79 words
A method of producing a tantalum dry-electrolytic capacitor comprising a sintered tantalum anode, oxidized to form a dielectric layer, and a semiconducting manganese dioxide cathode layer which is coated with a graphite layer serving as current supply, characterized in that after the formation of the manganese dioxide layer a thin layer of manganese dioxide is removed from the surface thereof by chemical treatment in an acetic acid-hydrogen peroxide bath, following which the cathode is coated with said graphite layer.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein the chemical treatment takes place for a period of 30 to 60 seconds.
Claim 4
Dependent Claim
30 words
A method according to claim 1, wherein the chemical treatment is followed by a rinsing operation in a dilute acetic acid solution with a pH value of less than 4.
Claim 5
Dependent Claim
19 words
A method according to claim 3, wherein the rinsing operation is effected in a bath containing 2.5% acetic acid.
Claim 6
Dependent Claim
30 words
A method according to claim 1, wherein the chemical treatment is effected in a 2.5% acetic acid bath, to which is added 40 ml of 30% hydrogen peroxide per liter.
Claim 7
Dependent Claim
20 words
A method according to claim 5, wherein the chemical treatment takes place for a period of 30 to 60 seconds.
Claim 8
Dependent Claim
30 words
A method according to claim 5, wherein the chemical treatment is followed by a rinsing operation in a dilute acetic acid solution with a pH value of less than 4.
Claim 9
Dependent Claim
19 words
A method according to claim 7, wherein the rinsing operation is effected in a bath containing 2.5% acetic acid.
References Cited (Backward Citations)
US3301704A
Cited
US3345208A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |