US4241378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Base metal electrode capacitor and method of making the same
Assignee: Erie Technological Products Inc
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Filing: 1978-06-12
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Granted: 1980-12-23
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Expires: 1998-06-12
Abstract
Abstract A monolithic ceramic capacitor with base metal electrodes fired in an atmosphere of oxygen at low partial pressure in which the reaction between the electrodes and the ceramic prevents conversion of the ceramic into the semiconductive state. The base metal is a transition metal or a transition metal alloy, preferably nickel. The method is usable with any green ceramic without changing the firing temperature. The only change required is from the normal oxygen partial pressure in the kiln open to the atmosphere to an atmosphere of much lower oxygen partial pressure.
Inventors
- 👤 John F. Dorrian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:55
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/005; H01G4/008; H01G4/0085; Y; Y10; Y10T; Y10T29/00; Y10T29/43; Y10T29/435
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
143 words
A method of making a monolithic capacitor having a sintered unitary body of titanate ceramic and electrodes embedded in the body which comprises preparing a green ceramic body with embedded electrodes of metal M, where M is selected from the group consisting of transition metals and/or transition metal alloys, firing the green ceramic body at a temperature to mature the ceramic and in an atmosphere of oxygen partial pressure low enough so that the skins of the electrodes oxidize and react with a major part of the ceramic and prevent reduction of said major part of the ceramic to the semi conductive state and the cores of the electrodes remain in the metallic state and heating the matured ceramic in an oxidizing atmosphere to reoxidize any part of the matured ceramic which is in the reduced semiconductive state without significantly oxidizing the electrodes.
Claim 2
Independent Claim
143 words
A method of making a monolithic capacitor having a sintered unitary body of titanate ceramic and electrodes embedded in the body which comprises preparing a green ceramic body with embedded electrodes of metal M, where M is selected from the group consisting of transition metals and/or transition metal alloys, firing the green ceramic body at a temperature to mature the ceramic and in an atmosphere of oxygen partial pressure low enough so that the skins of the electrodes oxidize and react with a major part of the ceramic and prevent reduction of said major part of the ceramic to the semi conductive state and the cores of the electrodes remain in the metallic state and heating the matured ceramic in an oxidizing atmosphere to reoxidize any part of the matured ceramic which is in the reduced semiconductive state without significantly oxidizing the electrodes.
Claim 3
Dependent Claim
12 words
The method of claim 1 in which the ceramic comprises barium titanate.
Claim 4
Independent Claim
179 words
The method of making a monolithic capacitor having a sintered unitary body of titanate ceramic and electrodes embedded in the body which comprises preparing a green ceramic body with embedded electrodes of metal M where M is selected from the group consisting of transition metal and/or transition metal alloys and the electrodes have terminal extensions extending to different outer surfaces of the body and a shield element of metal M is interleaved between adjacent terminal extensions and is spaced from the electrodes and terminal extensions, firing the green ceramic body at a temperature to mature the ceramic and in an atmosphere of oxygen partial pressure low enough so that the skins of the electrodes oxidize and react with a major part of the ceramic and prevent reduction of said major part of the ceramic to the semi conductive state and the cores of the electrodes remain in the metallic state and heating the matured ceramic in an oxidizing atmosphere to reoxidize any part of the matured ceramic which is in the reduced semiconductive state without significantly oxidizing the electrodes.
Claim 5
Independent Claim
179 words
The method of making a monolithic capacitor having a sintered unitary body of titanate ceramic and electrodes embedded in the body which comprises preparing a green ceramic body with embedded electrodes of metal M where M is selected from the group consisting of transition metal and/or transition metal alloys and the electrodes have terminal extensions extending to different outer surfaces of the body and a shield element of metal M is interleaved between adjacent terminal extensions and is spaced from the electrodes and terminal extensions, firing the green ceramic body at a temperature to mature the ceramic and in an atmosphere of oxygen partial pressure low enough so that the skins of the electrodes oxidize and react with a major part of the ceramic and prevent reduction of said major part of the ceramic to the semi conductive state and the cores of the electrodes remain in the metallic state and heating the matured ceramic in an oxidizing atmosphere to reoxidize any part of the matured ceramic which is in the reduced semiconductive state without significantly oxidizing the electrodes.
Claim 6
Dependent Claim
36 words
The method of claim 1 in which a shield layer of metal M is provided in an outer part of the green ceramic body which shield layer overlaps and is spaced from the immediately underlying electrode.
Claim 7
Dependent Claim
22 words
The method of claim 1 in which the reaction between the electrodes and the ceramic is in accordance with the equation ##EQU3##
Claim 8
Dependent Claim
17 words
The method of claim 1 in which the oxygen partial pressure is greater than 10 -7 atmosphere.
Claim 9
Dependent Claim
12 words
The method of claim 1 in which the metal M is nickel.
Claim 10
Dependent Claim
33 words
The method of claim 1 in which the metal M is selected from the group consisting of nickel, nickel-copper, nickel-zinc, nickel-sodium oxide, nickel-cobalt, cobalt-iron, nickel-iron, nickel-tantalum, chromium, nickel-chromium, cobalt, iron, nickel-tin, nickel-chromium oxide.
Claim 11
Dependent Claim
28 words
The method of claim 3 in which terminations comprising metal M are applied to outer surfaces of the green ceramic body and make connections to said terminal extensions.
Claim 12
Dependent Claim
128 words
A monolithic capacitor having a sintered unitary body of sintered ceramic and electrodes embedded in the green ceramic prior to sintering, the electrodes being of metal M, where M is selected from the group consisting of transition metals and/or transition metal alloys, the body having been matured in an atmosphere of oxygen partial pressure low enough so that the skins of the electrodes oxidize and react with a major part of the ceramic and prevents conversion of said major part into the semi conducting state and the cores of the electrodes remain in the metallic state and the matured ceramic having been heated in an oxidizing atmosphere to reoxidize any part of the matured ceramic which is in the reduced semi conductive state without significantly oxidizing the electrodes.
Claim 13
Dependent Claim
128 words
A monolithic capacitor having a sintered unitary body of sintered ceramic and electrodes embedded in the green ceramic prior to sintering, the electrodes being of metal M, where M is selected from the group consisting of transition metals and/or transition metal alloys, the body having been matured in an atmosphere of oxygen partial pressure low enough so that the skins of the electrodes oxidize and react with a major part of the ceramic and prevents conversion of said major part into the semi conducting state and the cores of the electrodes remain in the metallic state and the matured ceramic having been heated in an oxidizing atmosphere to reoxidize any part of the matured ceramic which is in the reduced semi conductive state without significantly oxidizing the electrodes.
Claim 14
Dependent Claim
12 words
The capacitor of claim 10 in which the ceramic comprises barium titanate.
Claim 15
Dependent Claim
43 words
The capacitor of claim 10 in which the electrodes have terminal extensions with alternate extensions extending to different outer surfaces of the body and a shield element of metal M is interleaved between alternate extensions and is spaced from the electrodes and extensions.
Claim 16
Dependent Claim
30 words
The capacitor of claim 10 in which a shield layer of metal M in the outer part of said ceramic body overlaps and is spaced from the immediately underlying electrode.
Claim 17
Dependent Claim
22 words
The capacitor of claim 10 in which the reaction between the electrodes and the ceramic is in accordance with the equation ##EQU4##
Claim 18
Dependent Claim
17 words
The capacitor of claim 10 in which the oxygen partial pressure is greater than 10 -7 atmospheres.
Claim 19
Dependent Claim
12 words
The method of claim 9 in which the metal M comprises nickel.
Claim 20
Dependent Claim
33 words
The capacitor of claim 10 in which the metal M is selected from the group consisting of nickel, nickel-copper, nickel-zinc, nickel-sodium oxide, nickel-cobalt, cobalt-iron, nickel-iron, nickel-tantalum, chromium, nickel-chromium, cobalt, iron, nickel-tin, nickel-chromium oxide.
Claim 21
Dependent Claim
28 words
The capacitor of claim 14 in which terminations comprising metal M applied to outer surfaces of the green ceramic prior to sintering make connections to said terminal extensions.
Claim 22
Dependent Claim
12 words
The capacitor of claim 18 in which the metal M comprises nickel.
Claim 23
Dependent Claim
12 words
The capacitor of claim 10 in which the metal M comprises nickel.
Claim 24
Dependent Claim
26 words
The method of claim 1 in which the reoxidizing is effected by increasing the oxygen partial pressure while cooling the matured ceramic from the firing temperature.
Claim 25
Dependent Claim
24 words
The method of claim 21 in which oxygen partial pressure while cooling from the firing temperature is of the order of 10 -3 atmospheres.
Claim 26
Dependent Claim
19 words
The method of claim 1 in which the reoxidizing is effected by air firing electrodes on the matured ceramic.
Claim 27
Dependent Claim
12 words
The method of claim 23 in which the electrodes are silver paint.
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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |