Patent US4073846A successfully refreshed from Google Patents.
US4073846A
Expired / Lapsed
US
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Reduction-reoxidation type semiconducting ceramic capacitor
Assignee: TDK Corp
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Filing: 1976-02-03
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Granted: 1978-02-14
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Expires: 1996-02-03
Abstract
Abstract An improved reduction-reoxidation type semiconducting ceramic capacitor and the method for producing the same are disclosed. The main components of the substrate of the capacitor are CaTiO3, SrTiO3 and Bi2O3xxTiO2. Said substrate also contains at least one member selected from the group consisting of manganese, cobalt, nickel, chromium, vanadium, niobium, tantalum, lanthanum and cerium ions in total amounts of 0.025 to 0.4% by weight. The capacitor according to the present invention excels, in the temperature independency of the capacitance and tan delta , etc.
Inventors
- 👤 Hitoshi Masumura
- 👤 Shinobu Fujiwara
- 👤 Hitoshi Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:41
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1272; C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/475
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
147 words
A method for producing semiconducting ceramic bodies which comprises: (a) mixing strontium titanate, calcium titanate, bismuth oxide and titanium oxide so as to give the composition falling within the tetragonal area described by the line A-B-C-D in FIG. 6, and further adding at least one member selected from the group consisting of manganese, cobalt, nickel, chromium, vanadium, niobium, tantalum, lanthanum and cerium ions in total amounts of 0.025 to 0.4% by weight to the resulting mixture; (b) pressing the compositions into desired shape; (c) sintering the thus obtained shaped bodies at a temperature of about 1350° C in an oxidizing atmosphere for about 2 hours; (d) firing the composition of at (C) a temperature of about 850° C in a reducing atmosphere for about an hour, and; (e) further firing the composition at a temperature of about 780° C in an oxidizing atmosphere for about an hour.
Claim 2
Independent Claim
147 words
A method for producing semiconducting ceramic bodies which comprises: (a) mixing strontium titanate, calcium titanate, bismuth oxide and titanium oxide so as to give the composition falling within the tetragonal area described by the line A-B-C-D in FIG. 6, and further adding at least one member selected from the group consisting of manganese, cobalt, nickel, chromium, vanadium, niobium, tantalum, lanthanum and cerium ions in total amounts of 0.025 to 0.4% by weight to the resulting mixture; (b) pressing the compositions into desired shape; (c) sintering the thus obtained shaped bodies at a temperature of about 1350° C in an oxidizing atmosphere for about 2 hours; (d) firing the composition of at (C) a temperature of about 850° C in a reducing atmosphere for about an hour, and; (e) further firing the composition at a temperature of about 780° C in an oxidizing atmosphere for about an hour.
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) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |