Dielectric ceramic composition and monolithic ceramic capacitor

A dielectric and composition technology, applied in the field of laminated ceramic capacitors, can solve the problems of low relative permittivity and inappropriateness, and achieve the effect of increasing the resistivity and increasing the resistivity

Active Publication Date: 2008-04-09
MURATA MFG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

That is, the tungsten bronze type composite oxide has a relative permittivity as low as less than 2000, and is not suitable as a dielectric ceramic material for laminated ceramic capacitors.
In addition, the sinterability can be improved by adding Mn. However, as shown in Table 2 of Patent Document 1, the relative permittivity decreases as the amount of Mn added increases. Therefore, as a dielectric ceramic material for multilayer ceramic capacitors There is a problem in use

Method used

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  • Dielectric ceramic composition and monolithic ceramic capacitor

Examples

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Embodiment 1

[0031] In this example, relative to the main component KSr 2 Nb 5 o 15 Mn was added, and the influence of the Mn content was investigated. That is, the dielectric ceramic compositions shown in Table 1 were prepared according to the following procedures (1) and (2), and multilayer ceramic capacitors of Sample Nos. 1 to 23 were fabricated using these dielectric ceramic compositions according to the following procedures. Next, the electrical characteristics of these multilayer ceramic capacitors were evaluated, and Table 1 shows the evaluation results. In addition, in Table 1, the samples marked with * are substances outside the scope of the present invention.

[0032] (1) Modulation of dielectric ceramic raw materials

[0033] Preparation of pre-synthesized tungsten bronze type composite oxide KSr as the main component 2 Nb 5 o 15 Powder, in addition, prepared MnCO as the raw material of the subcomponent added to the main component 3 、Cr 2 o 3 、CoCO 3 , Fe 2 o 3 , N...

Embodiment 2

[0045] In this embodiment, the basic composition of the main component is KSr 2 Nb 5 o 15 The dielectric ceramic composition KSr whose Nb site is replaced by subcomponent A such as Mn shown in Table 2 2 (Nb 5-x A x )O 15 , in the same manner as in Example 1, a multilayer ceramic capacitor was produced, and the same evaluation as in Example 1 was performed to investigate the influence of the substitution amount x of the subcomponent A in the main component of Example 1. In addition, in Table 2, the samples marked with * are substances outside the scope of the present invention.

[0046] (1) Modulation of dielectric ceramic raw materials

[0047] In this example, the basic composition KSr as the main component 2 Nb 5 o 15 raw material, prepared K 2 CO 3 , Nb 2 o 5 , SrCO 3 For each powder, MnCO, which is the raw material of subcomponent A for substituting a part of Nb in the basic composition, was prepared separately. 3 、Cr 2 o 3 、CoCO 3 , Fe 2 o 3 , NiO, ZnO...

Embodiment 3

[0059] In the present embodiment, adopt the basic composition of main component as shown in table 3 to be KSr 2 Nb 5 o 15 Dielectric ceramic composition (K 1-y Na y )Sr 2 (Nb 5-x A x )O 15 , A laminated ceramic capacitor was produced in the same manner as in Example 2, and the same evaluation as in Example 2 was performed to investigate the influence of the substitution amount y of Na at the K site in the main component of Example 2. In addition, in Table 3, the samples marked with * are substances outside the scope of the present invention.

[0060] (1) Modulation of dielectric ceramic raw materials

[0061] In this example, the basic composition KSr as the main component 2 Nb 5 o 15 The original raw materials were prepared separately for K 2 CO 3 , Nb 2 o 5 , SrCO 3 Each of the powders, Na as the raw material of the subcomponent Na for substituting a part of K of the basic composition 2 CO 3 powder, and MnCO as the raw material of subcomponent Mn for substi...

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Abstract

The present invention provides a dielectric ceramic composition which can solve problems, involved in a conventional piezoelectric ceramic for an actuator using a tungsten bronze type composite oxide, i.e., a problem that the specific permittivity is so low (less than 2000) that the piezoelectric ceramic is unsuitable as a dielectric ceramic material for laminated ceramic capacitors, and a problem that, although Mn has the effect of improving the degree of sintering, since the specific permittivity is lowered with increasing the amount of Mn added, the conventional piezoelectric ceramic, when used as a dielectric ceramic material for laminated ceramic capacitors, poses a problem. The dielectric ceramic composition is composed mainly of a tungsten bronze type composite oxide represented by a compositional formula (K1-yNay)Sr2Nb5O15, wherein 0 = y < 0.2, and contains 0.1 to 40 parts by mole, based on 100 parts by mole of the main component, of Mn as an auxiliary component.

Description

technical field [0001] The present invention relates to a dielectric ceramic composition and a laminated ceramic capacitor, and more specifically relates to a KSr with a tungsten-bronze (tungsten-bronze) structure 2 Nb 5 o 15 A dielectric ceramic composition as a basic composition and a multilayer ceramic capacitor using the dielectric ceramic composition. Background technique [0002] As a technique using a composite oxide having a tungsten bronze structure (hereinafter, referred to as “tungsten bronze composite oxide”), piezoelectric ceramics for actuators described in Patent Document 1, for example, is known. The piezoelectric ceramics used for actuators are composed of a general formula: NaSr 2 Nb 5 o 15 The tungsten-bronze-type composite oxide represented by is composed mainly of crystal particles in which a part of Nb is substituted with V and / or Ta. By substituting part of Nb with V and / or Ta, the Curie temperature T c Increase to above 150°C, while increasing ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/00H01G4/12
CPCC04B35/495C04B2235/3206C04B2235/3201B32B2311/08C04B2235/3215C04B2235/76C04B2235/6582C04B2235/6025C04B2235/3213C04B2235/3279C04B2235/6584C04B2237/345C04B2235/96C04B2235/3262C04B2235/3272C04B2235/3418H01G4/1254C04B2235/365C04B2235/663C04B2235/3208C04B2235/3251H01G4/30C04B35/64C04B2237/408C04B2235/656C04B35/62665C04B2235/6588C04B2235/3241C04B2235/3275C04B35/00H01G4/12
Inventor 竹田敏和和田信之高桥夕香子
Owner MURATA MFG CO LTD
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