US4403236A
Expired / Lapsed
US
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Boundary layer type semiconducting ceramic capacitors with high capacitance
Assignee: Murata Manufacturing Co Ltd
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Filing: 1980-10-02
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Granted: 1983-09-06
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Expires: 2000-10-02
Abstract
Abstract A boundary layer type semiconducting ceramic capacitor with high capacitance is disclosed. The capacitor comprises a semiconducting ceramic body in which grain boundaries on crystal grains of the semiconducting ceramic body are insulated, characterized in that said semiconducting ceramic body has a composition consisting essentially of 98.1 to 99.88 mole % of a main component (Sr 1-x Ba x )Tio 3 or (Sr 1-x Ba x )TiO 3 modified with a titanete and/or a zirconate, wherein x is a mole fraction of Ba and takes a value ranging from 0.30 to 0.50, and 0.1 to 1.0 mole % of at least one semiconductorizing agent selected from the group consisting of rare earth elements, Nb, Ta and W, and that said grain boundaries of the crystal grains are insulated by at least one insulating agent selected from the group consisting of Mn, Bi, Cu, Pb, B and Si, and that the maximum crystal grain present in the semiconducting ceramic body has a grain size ranging from 100 to 250μ. The composition contains 0.02 to 0.2 mole % of Mn as a mineralizing agent or insulating agent. The composition may further contain at least one of 0.05 to 0.5 mole % of SiO 2 and 0.02 to 0.2 mole % of Al 2 O 3 .
Inventors
- 👤 Haruhumi Mandai
- 👤 Kunitaro Nishimura
- 👤 Masami Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:28
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/47; C04B35/48; C04B35/49; C04B35/622; C04B35/626; C04B35/62605; C04B35/62695; C04B41/00; C04B41/009; C04B41/45; C04B41/52; C04B41/80; C04B41/81; C04B41/89; C04B41/90; H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1272; H01G4/1281; C04B2111/00; C04B2111/00474; C04B2111/00844; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3205; C04B2235/3208; C04B2235/3213; C04B2235/3215; C04B2235/3217; C04B2235/3224; C04B2235/3225; C04B2235/3227; C04B2235/3231; C04B2235/3232; C04B2235/3234; C04B2235/3236; C04B2235/3244; C04B2235/3248; C04B2235/3251; C04B2235/3258; C04B2235/3262; C04B2235/3281; C04B2235/3296; C04B2235/3298; C04B2235/34; C04B2235/3418; C04B2235/65; C04B2235/652; C04B2235/658; C04B2235/6582; C04B2235/66; C04B2235/661; C04B2235/70; C04B2235/74; C04B2235/78; C04B2235/786; C04B2235/80; C04B2235/85
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
164 words
A boundary layer type semiconducting ceramic capacitor comprising a semiconducting ceramic body in which grain boundaries on crystal grans of the semiconducting ceramic body are insulated, characterized in that said semiconducting ceramic body has a composition consisting essentially of 98.1 to 99.9 mole % of a main component (Sr 1-x Ba x )TiO 3 or (Sr 1-x Ba x )TiO 3 modified with not more than 10 mole % of calcium titanate and/or barium zirconate, wherein x is a mole fraction of Ba from 0.30 to 0.50, and 0.1 to 1.0 mole % of at least one semiconductorizing agent selected from the group consisting of a rare earth element, Nb, Ta and W, and that said grain boundaries of the crystal grains are insulated by at least one insulating agent selected from the group consisting of Mn, Bi, Cu, Pb, B and Si, and that the maximum crystal grain present in the semiconducting ceramic body has a grain size ranging from 100μ to 250μ.
Claim 2
Dependent Claim
164 words
A boundary layer type semiconducting ceramic capacitor comprising a semiconducting ceramic body in which grain boundaries on crystal grans of the semiconducting ceramic body are insulated, characterized in that said semiconducting ceramic body has a composition consisting essentially of 98.1 to 99.9 mole % of a main component (Sr 1-x Ba x )TiO 3 or (Sr 1-x Ba x )TiO 3 modified with not more than 10 mole % of calcium titanate and/or barium zirconate, wherein x is a mole fraction of Ba from 0.30 to 0.50, and 0.1 to 1.0 mole % of at least one semiconductorizing agent selected from the group consisting of a rare earth element, Nb, Ta and W, and that said grain boundaries of the crystal grains are insulated by at least one insulating agent selected from the group consisting of Mn, Bi, Cu, Pb, B and Si, and that the maximum crystal grain present in the semiconducting ceramic body has a grain size ranging from 100μ to 250μ.
Claim 3
Dependent Claim
22 words
The boundary layer type semiconducting ceramic capacitor according to claim 1 wherein said composition contains 0.02 to 0.2 mole % of Mn.
Claim 4
Dependent Claim
27 words
The boundary layer type semiconducting ceramic capacitor according to claim 2 wherein Mn is present in at least one of the grain boundaries and the crystal grains.
Claim 5
Dependent Claim
40 words
The boundary layer type semiconducting ceramic capacitor according to claim 1 wherein said composition further contains at least one of 0.05 to 0.5 mole % of SiO 2 and 0.02 to 0.2 mole % of Al 2 O 3 .
Claim 6
Dependent Claim
40 words
The boundary layer type semiconducting ceramic capacitor according to claim 2 wherein said composition further contains at least one of 0.05 to 0.5 mole % of SiO 2 and 0.02 to 0.2 mole % of Al 2 O 3 .
Claim 7
Dependent Claim
19 words
The boundary layer type semiconducting ceramic capacitor according to claim 2 wherein Mn is present in the crystal grains.
Claim 8
Dependent Claim
43 words
The boundary layer type semiconducting ceramic capacitor according to claim 2 wherein Mn is present in the grain boundaries of the crystal grains, and wherein said grain boundaries of the crystal grains are insulated by Mn and at least one other insulating agent.
Claim 9
Dependent Claim
25 words
The boundary layer type semiconducting ceramic capacitor according to claim 1 in which the amount of the main component is 98.1 to 99.88 mole %.
Claim 10
Dependent Claim
27 words
The boundary layer type semiconducting ceramic capacitor according to claim 8 wherein Mn is present at at least one of the grain boundaries and the crystal grains.
Claim 11
Dependent Claim
19 words
The boundary layer type semiconducting ceramic capacitor according to claim 9 wherein Mn is present at the crystal grains.
Claim 12
Dependent Claim
40 words
The boundary layer type semiconducting ceramic capacitor according to claim 10 wherein said composition further includes at least one of 0.05 to 0.5 mole % of SiO 2 and 0.02 to 0.2 mole % of Al 2 O 3 .
Claim 13
Dependent Claim
40 words
The boundary layer type semiconducting ceramic capacitor according to claim 9 wherein said composition further includes at least one of 0.05 to 0.5 mole % of SiO 2 and 0.02 to 0.2 mole % of Al 2 O 3 .
Claim 14
Dependent Claim
23 words
The boundary layer type semiconducting ceramic capacitor according to claim 8 wherein said main component is (Sr 1-x Ba x )TiO 3 .
Claim 15
Dependent Claim
23 words
The boundary layer type semiconducting ceramic capacitor according to claim 1 wherein said main component is (Sr 1-x Ba x )TiO 3 .
References Cited (Backward Citations)
US4143207A
Cited
US4222783A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |