US5734545A
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Monolithic ceramic capacitor
Assignee: Murata Manufacturing Co Ltd
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Filing: 1996-12-18
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Granted: 1998-03-31
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Expires: 2016-12-18
Abstract
Abstract Disclosed is a monolithic ceramic capacitor comprising dielectric ceramic layers made from a material which comprises an essential component of (1-α-β){BaO} m •TiO 2 +αRe 2 O 3 30 β(Mn 1-x-y Ni x Co y )O (0.0025≦α≦0.025; 0.0025≦β≦0.05; β/α≦4; 0≦x<1.0; 0≦y<1.0; 0≦x+y<1.0; 1.000<m≦1.035) and from about 0.1 to 3.0 mols, relative to 100 mols of the essential component, of a side component MgO, and contains from about 0.2 to 3.0 parts by weight, relative to 100 parts by weight of said components, of an oxide of the type of Li 2 O-B 2 O 3 -(Si,Ti)O 2 . The capacitor is low-priced and can be small-sized, while having large-capacity. It has a dielectric constant of 3000 or more, and has a high insulating resistance of 6000 MΩ•μF or more and 2000 MΩ•μF or more at 2 KV/mm and at room temperature and 125° C., respectively, and 2000 MΩ•μF or more and 500 MΩ•μF or more at 20 KV/mm and at room temperature and 125° C., respectively. It has temperature-dependent capacitance that satisfies the B-level characteristic standard stipulated in the JIS Standard and the X7R-level characteristic standard stipulated in the EIA Standard, and has high reliability irrespective of the presence or absence of plate film covering it.
Inventors
- 👤 Harunobu Sano
- 👤 Yukio Hamaji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:57
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1209; H01G4/1218; H01G4/1227; C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
239 words
A monolithic ceramic capacitor composed of; a plurality of superposed dielectric ceramic layers, a plurality of inner electrodes each of which is disposed between adjacent dielectric ceramic layers in such a manner that one end of each inner electrode is exposed at an end of the dielectric ceramic layers, and outer electrodes electrically connected with the exposed inner electrodes, the monolithic ceramic capacitor being characterized in that the dielectric ceramic layers comprises a barium titanate having a content of alkali metal oxide impurities of about 0.02% by weight or less and having the compositional formula: (1-α-β){BaO} m •TiO 2 +αRe 2 O 3 +β(Mn 1-x-y Ni x Co y )O where Re 2 O 3 is at least one member of the group consisting of Y 2 O 3 , Tb 2 O 3 , Dy 2 O 3 , Ho 2 O 3 , Er 2 O 3 and Yb 2 O 3 ; and α, β, m, x and y are as follows: 0.0025≦α≦0.025 0.0025≦β≦0.05 β/α≦4 0≦x<1.0 0≦y<1.0 0≦x+y<1.0 1.000<m≦1.035; magnesium oxide in an amount of from about 0.1 to 3.0 mols in terms of MgO relative to 100 mols of said titanate and from about 0.2 to 3.0 parts by weight, relative to 100 parts by weight of said titanate and magnesium oxide of an optionally Li 2 O-containing B 2 O 3 -(Si,Ti)O 2 oxide; and the inner electrodes being nickel or a nickel alloy.
Claim 2
Dependent Claim
239 words
A monolithic ceramic capacitor composed of; a plurality of superposed dielectric ceramic layers, a plurality of inner electrodes each of which is disposed between adjacent dielectric ceramic layers in such a manner that one end of each inner electrode is exposed at an end of the dielectric ceramic layers, and outer electrodes electrically connected with the exposed inner electrodes, the monolithic ceramic capacitor being characterized in that the dielectric ceramic layers comprises a barium titanate having a content of alkali metal oxide impurities of about 0.02% by weight or less and having the compositional formula: (1-α-β){BaO} m •TiO 2 +αRe 2 O 3 +β(Mn 1-x-y Ni x Co y )O where Re 2 O 3 is at least one member of the group consisting of Y 2 O 3 , Tb 2 O 3 , Dy 2 O 3 , Ho 2 O 3 , Er 2 O 3 and Yb 2 O 3 ; and α, β, m, x and y are as follows: 0.0025≦α≦0.025 0.0025≦β≦0.05 β/α≦4 0≦x<1.0 0≦y<1.0 0≦x+y<1.0 1.000<m≦1.035; magnesium oxide in an amount of from about 0.1 to 3.0 mols in terms of MgO relative to 100 mols of said titanate and from about 0.2 to 3.0 parts by weight, relative to 100 parts by weight of said titanate and magnesium oxide of an optionally Li 2 O-containing B 2 O 3 -(Si,Ti)O 2 oxide; and the inner electrodes being nickel or a nickel alloy.
Claim 3
Dependent Claim
149 words
The monolithic ceramic capacitor as claimed in claim 1, wherein said B 2 O 3 -(Si,Ti)O 2 oxide has a composition which falls within the area surrounded by six lines formed by connecting six points, represented by mol %, of: A (0, 20, 80) B (19, 1, 80) C (49, 1, 50) D (45, 50, 5) E (20, 75, 5) F (0, 80, 20) in a triangular phase diagram of {Li 2 O, B 2 O 3 , (Si w Ti 1-w )O 2 }, in which 0.3≦w<1.02, and further contains about 20 parts by weight or less, relative to 100 parts by weight of said Li 2 O, B 2 O 3 , and (Si w Ti 1-w )O 2 components, of at least one of Al 2 O 3 and ZrO 2 , provided that the ZrO 2 content is about 10 parts by weight or less.
Claim 4
Dependent Claim
22 words
The monolithic ceramic capacitor as claimed in claim 2, wherein said ceramic has a grain size of less than about 1 μm.
Claim 5
Dependent Claim
78 words
The monolithic ceramic capacitor as claimed in claim 3, wherein 0.008≦α≦0.02, 0.003≦β≦0.024, β/α≦2, 0.1≦x≦0.9, 0.1≦y<0.9, and 1.005<m≦1.015; said magnesium oxide is in an amount of from about 0.5 to 2 mols in terms of MgO relative to 100 mols of said titanate; and there is from about 0.8 to 2 parts by weight, relative to 100 parts by weight of said titanate and magnesium oxide of the optionally Li 2 O-containing B 2 O 3 -(Si,Ti)O 2 oxide.
Claim 6
Dependent Claim
38 words
The monolithic ceramic capacitor as claimed in claim 4, wherein the content of alkali metal oxide impurities is about 0.015% by weight or less, said ceramic has a grain size of less than about 1 μm, and 0.3≦w<1.0.
Claim 7
Dependent Claim
31 words
The monolithic ceramic capacitor as claimed in claim 5 having two separate outer electrodes on the outside surface of the capacitor, each of which is electrically connected to an inner electrode.
Claim 8
Dependent Claim
27 words
The monolithic ceramic capacitor as claimed in claim 6, wherein the outer electrodes comprise a sintered layer of an electroconductive metal powder optionally containing a glass frit.
Claim 9
Dependent Claim
42 words
The monolithic ceramic capacitor as claimed in claim 7, wherein the outer electrodes are composed of a first sintered layer of an electroconductive metal powder optionally containing a glass frit added thereto, and a second plated layer formed on the first layer.
Claim 10
Dependent Claim
30 words
The monolithic ceramic capacitor as claimed in claim 2, wherein Re 2 O 3 is Y 2 O 3 , Dy 2 O 3 or Er 2 O 3 .
Claim 11
Dependent Claim
23 words
The monolithic ceramic capacitor as claimed in claim 2, wherein Re 2 O 3 is a combination of two members of said group.
Claim 12
Dependent Claim
31 words
The monolithic ceramic capacitor as claimed in claim 2 having two separate outer electrodes on the outside surface of the capacitor, each of which is electrically connected to an inner electrode.
Claim 13
Dependent Claim
27 words
The monolithic ceramic capacitor as claimed in claim 11, wherein the outer electrodes comprise a sintered layer of an electroconductive metal powder optionally containing a glass frit.
Claim 14
Dependent Claim
42 words
The monolithic ceramic capacitor as claimed in claim 12, wherein the outer electrodes are composed of a first sintered layer of an electroconductive metal powder optionally containing a glass frit added thereto, and a second plated layer formed on the first layer.
Claim 15
Dependent Claim
31 words
The monolithic ceramic capacitor as claimed in claim 1 having two separate outer electrodes on the outside surface of the capacitor, each of which is electrically connected to an inner electrode.
Claim 16
Dependent Claim
27 words
The monolithic ceramic capacitor as claimed in claim 14, wherein the outer electrodes comprise a sintered layer of an electroconductive metal powder optionally containing a glass frit.
Claim 17
Dependent Claim
42 words
The monolithic ceramic capacitor as claimed in claim 15, wherein the outer electrodes are composed of a first sintered layer of an electroconductive metal powder optionally containing a glass frit added thereto, and a second plated layer formed on the first layer.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-03-30 | 2001-09-29 | 2002-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-03-30 | 2005-09-29 | 2006-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-03-30 | 2009-09-29 | 2010-03-31 | $7700.00 | Window Closed / Lapsed |