US4110815A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid electrolytic capacitor
Assignee: Lignes Telegraphiques et Telephoniques LTT SA
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Filing: 1976-09-28
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Granted: 1978-08-29
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Expires: 1996-09-28
Abstract
Abstract In solid tantalum electrolytic capacitors, an additive is introduced in the oxide dielectric layer consisting of an ion with a valency different from 5 in a concentration variable across the thickness of the layer. The nature of the additive is selected according to the characteristic to be improved.
Inventors
- 👤 Gilbert Frade
- 👤 Balint Escher
- 👤 Dominique Prince
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:28
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/0029; H01G9/0032
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
75 words
In a solid electrolyte capacitor made of a sintered tantalum anode, a dielectric consisting of a tantalum oxide layer obtained through anodic oxidation of said tantalum anode and a cathode comprising manganese dioxide which covers said tantalum oxide layer and a conductive layer deposited on said manganese dioxide, the improvement which comprises an impurity selected from the group consisting of trivalent impurities and hexavalent impurities distributed non-uniformly through the thickness of said tantalum oxide layer.
Claim 2
Dependent Claim
75 words
In a solid electrolyte capacitor made of a sintered tantalum anode, a dielectric consisting of a tantalum oxide layer obtained through anodic oxidation of said tantalum anode and a cathode comprising manganese dioxide which covers said tantalum oxide layer and a conductive layer deposited on said manganese dioxide, the improvement which comprises an impurity selected from the group consisting of trivalent impurities and hexavalent impurities distributed non-uniformly through the thickness of said tantalum oxide layer.
Claim 3
Dependent Claim
62 words
The capacitor of claim 1 wherein said impurity is introduced into said tantalum oxide layer by immersing said sintered tantalum anode in an acidic solution containing a small concentration of ions of a metal selected from the group consisting of boron, aluminum and molybdenum and electrically oxidizing a portion of said sintered tantalum anode while it is immersed in said acidic solution.
Claim 4
Dependent Claim
48 words
The capacitor of claim 1 wherein said dielectric layer of tantalum oxide is formed on particles of tantalum metal and the resulting oxide layer is subsequently covered with manganese dioxide and said impurity is introduced into said tantalum oxide layer after said tantalum oxide layer has been formed.
Claim 5
Dependent Claim
72 words
In a solid electrolyte capacitor made of a sintered tantalum anode, a dielectric consisting of a tantalum oxide layer grown through anodic oxidation of said anode, a cathode comprising manganese dioxide which covers said tantalum oxide layer and a conductive layer deposited on said manganese dioxide, the improvement which comprises an impurity that is hexavalent distributed non-uniformly through the thickness of said tantalum oxide layer with a maximum concentration proximal said anode.
Claim 6
Dependent Claim
72 words
In a solid electrolyte capacitor made of a sintered tantalum anode, a dielectric consisting of a tantalum oxide layer grown through anodic oxidation of said anode, a cathode comprising manganese dioxide which covers said tantalum oxide layer and a conductive layer deposited on said manganese dioxide, the improvement which comprises an impurity that is hexavalent distributed non-uniformly through the thickness of said tantalum oxide layer with a maximum concentration proximal said anode.
Claim 7
Dependent Claim
11 words
The capacitor of claim 4 wherein said impurity is hexavalent molybdenum.
Claim 8
Dependent Claim
72 words
In a solid electrolyte capacitor made of a sintered tantalum anode, a dielectric consisting of a tantalum oxide layer grown through anodic oxidation of said anode, a cathode comprising manganese dioxide which covers said tantalum oxide layer and a conductive layer deposited on said manganese dioxide, the improvement which comprises an impurity that is trivalent distributed non-uniformly through the thickness of said tantalum oxide layer with a minimum concentration proximal said anode.
Claim 9
Dependent Claim
72 words
In a solid electrolyte capacitor made of a sintered tantalum anode, a dielectric consisting of a tantalum oxide layer grown through anodic oxidation of said anode, a cathode comprising manganese dioxide which covers said tantalum oxide layer and a conductive layer deposited on said manganese dioxide, the improvement which comprises an impurity that is trivalent distributed non-uniformly through the thickness of said tantalum oxide layer with a minimum concentration proximal said anode.
Claim 10
Dependent Claim
11 words
The capacitor of claim 6 wherein said impurity is trivalent boron.
Claim 11
Dependent Claim
11 words
The capacitor of claim 6 wherein said impurity is trivalent aluminum.
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) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |