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High dielectric constant type ceramic composition

Assignee: Toshiba Corp
•
Filing: 1987-11-02
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Granted: 1989-11-21
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Expires: 2007-11-02
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Abstract

Abstract When a portion of the Pb of a Pb(Zn 1/3 Nb 2/3 )O 3 -based ceramic composition within the region bounded by lines connecting a, b, c, d, e and f points in the ternary composition diagram of the accompanying FIG. 1 is substituted by a small amount of Ca, a high dielectric constant type ceramic composition is obtained which has a small temperature coefficient of dielectric constant and which is effective as a material for multilayer ceramic capacitors.

Inventors

  • 👤 Osamu Furukawa
  • 👤 Mitsuo Harata
  • 👤 Takaaki Yasumoto
  • 👤 Motomasa Imai

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 21:15
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/495; C04B35/497; C04B35/499

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 129 words
A high dielectric constant ceramic composition, characterized in that said composition is represented by the general formula: xPb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -- yPb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 --zPbTiO.sub.3, wherein a portion of Pb of the composition within lines connecting the following points a, b, c, d, e' and f' of a ternary composition diagram having the following apexes of respective components, is substituted by from 2 to 30 mole % of calcium: ______________________________________ a: (x = 0.60, y = 0.40, z = 0.00) b: (x = 0.60, y = 0.05, z = 0.35) c: (x = 0.45, y = 0.05, z = 0.50) d: (x = 0.01, y = 0.49, z = 0.50) e' (x = 0.01, y = 0.8, z = 0.19) f' (x = 0.5, y = 0.5, z = 0) ______________________________________
Claim 2
Dependent Claim 129 words
A high dielectric constant ceramic composition, characterized in that said composition is represented by the general formula: xPb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -- yPb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 --zPbTiO.sub.3, wherein a portion of Pb of the composition within lines connecting the following points a, b, c, d, e' and f' of a ternary composition diagram having the following apexes of respective components, is substituted by from 2 to 30 mole % of calcium: ______________________________________ a: (x = 0.60, y = 0.40, z = 0.00) b: (x = 0.60, y = 0.05, z = 0.35) c: (x = 0.45, y = 0.05, z = 0.50) d: (x = 0.01, y = 0.49, z = 0.50) e' (x = 0.01, y = 0.8, z = 0.19) f' (x = 0.5, y = 0.5, z = 0) ______________________________________
Claim 3
Dependent Claim 62 words
The high dielectric constant ceramic composition according to claim 1, wherein when lead and calcium elements are represented by A, further zinc, magnesium, niobium and titanium elements are represented by B and the chemical formula of the complex compound is represented by ABO 3 , the molar ratio of A to B is in the range shown in the formula: 1.00≦A/B <1.10
Claim 4
Dependent Claim 49 words
The high dielectric constant ceramic composition according to claim 1 which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 5
Dependent Claim 26 words
The high dielectric constant ceramic composition according to claim 1, wherein b is b' (x=0.6, y=0.2, and z=0.2), and c is c' ((x=0.3, y=0.2, and z=0.5).
Claim 6
Dependent Claim 16 words
The high dielectric constant ceramic composition according to claim 1, wherein z is at least 0.01.
Claim 7
Dependent Claim 30 words
A multilayer ceramic capacitor having at least a pair of internal electrodes, said capacitor being produced using the high dielectric constant ceramic composition according to claim 1 as a dielectric.
Claim 8
Dependent Claim 27 words
The capacitor according to claim 6, wherein the electrodes are formed from a low melting metal selected from the group consisting of silver, copper, nickel and aluminum.
Claim 9
Dependent Claim 49 words
The high dielectric constant ceramic composition according to claim 2, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 10
Dependent Claim 49 words
The high dielectric constant ceramic composition according to claim 3, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 11
Dependent Claim 49 words
The high dielectric constant ceramic composition according to claim 4, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 12
Dependent Claim 49 words
The high dielectric constant ceramic composition according to claim 5, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .

References Cited (Backward Citations)

US4265668A Cited
JPS5725607A Cited
US4339544A Cited
JPS57188456A Cited
EP0103304A2 Cited
US4536821A Cited
US4753905A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-11-20 1993-05-22 1993-11-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-11-20 1997-05-22 1997-11-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-11-20 2001-05-22 2001-11-21 $7700.00 Window Closed / Lapsed

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