JP2002234771A - Oxide powder having tetragonal perovskite structure, method for producing the same, dielectric ceramic and multilayer ceramic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an oxide powder having a tetragonal perovskite structure, capable of thinning each dielectric ceramic layer in a multilayer ceramic capacitor and capable of imparting satisfactory ferroelectricity to the capacitor. SOLUTION: An oxide powder having a cubic perovskite structure synthesized by a wet process is heat-treated under <=6×103 Pa pressure to obtain the objective oxide powder having a tetragonal perovskite structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxide powder having a tetragonal perovskite structure, a method for producing the same, a dielectric ceramic, and a multilayer ceramic capacitor. The present invention relates to an improvement for achieving a high degree of ferroelectricity and achieving sufficient ferroelectricity.

[0002]

2. Description of the Related Art Multilayer ceramic capacitors have been reduced in size and cost, and the thickness of a dielectric ceramic layer provided therein has been reduced to about 3 μm, and also as a material for internal electrodes. Base metals such as copper, nickel and the like have been used. In recent years, the thickness of the dielectric ceramic layer has been further reduced, and a dielectric ceramic layer having a thickness of about 1 μm or less has been developed.

However, when the dielectric ceramic layer becomes thinner as described above, the electric field applied to the dielectric ceramic layer increases, and a dielectric material whose change in the dielectric constant due to the electric field is large is used as the material of the ceramic layer. Has a problem. Further, as the thickness of the dielectric ceramic layer is reduced, the number of crystal grains of the ceramic in the thickness direction of the ceramic layer is reduced, which causes a problem in reliability.

In order to cope with such a situation, it is possible to increase the number of crystal grains of the ceramic in the thickness direction of the dielectric ceramic layer by reducing the crystal grain diameter of the ceramic, thereby improving the reliability. For example, Japanese Patent Application Laid-Open No. 9-2410 discloses
No. 74 and Japanese Patent Application Laid-Open No. 9-241075. In addition, Japanese Patent Application Laid-Open Nos. 11-273985 and 11-273986 propose barium titanate-based materials capable of coping with reducing the thickness of a dielectric ceramic layer to about 1 μm.

The above-mentioned barium titanate-based ceramic material powder has to be prepared as a ceramic having a small crystal particle diameter, so that it must be prepared as a powder having a small particle diameter. In order to obtain the above ceramic material powder, it is preferable to synthesize by a wet method such as a hydrolysis method or a hydrothermal synthesis method.

However, the barium titanate-based ceramic material powder synthesized by the wet method has about 0.2 to 3% by weight of hydroxyl groups remaining in the particles, and although the particle diameter is small, it is cubic. , Even if it is tetragonal, the ratio of the c-axis to the a-axis of the crystal lattice of the perovskite structure, ie, c / a
There is a problem that the axial ratio is small and the ferroelectricity may not be sufficient as a material for a capacitor.

In order to solve this problem, the synthesized barium titanate-based ceramic material powder is reheat-treated in the air to remove the hydroxyl groups.
Barium titanate-based ceramic material powders having a large a-axis ratio and exhibiting sufficient ferroelectricity have been obtained.

[0008]

However, since the barium titanate-based ceramic material powder grows as a result of the reheat treatment as described above, titanic acid having a small particle diameter of, for example, 0.15 μm or less is obtained. Another problem may be encountered in that obtaining a barium-based ceramic material powder is again difficult.

In a multilayer ceramic capacitor using such a barium titanate-based ceramic in a dielectric ceramic layer, short-circuit failure occurs when the thickness of the dielectric ceramic layer is reduced to, for example, about 0.6 μm or less. Or other problems such as reduced reliability.

Accordingly, an object of the present invention is to provide a method for producing an oxide powder having a tetragonal perovskite structure, which is advantageously used to obtain a dielectric ceramic capable of solving the above-mentioned problems, and a method for producing the same. It is an object of the present invention to provide an obtained oxide powder, a dielectric ceramic produced by using the oxide powder, and a multilayer ceramic capacitor constituted by using the dielectric ceramic.

[0011]

A method for producing an oxide powder having a tetragonal perovskite structure according to the present invention comprises the steps of synthesizing an oxide powder having a cubic perovskite structure by a wet method, Heat-treating the oxide powder having a pressure of 6 × 10 ³ Pa or less.

The oxide powder having a cubic perovskite structure synthesized by the above-mentioned wet method has a particle diameter of:
It is preferably from 0.01 to 0.1 μm.

In the heat treatment step, 6
Preferably, a temperature in the range from 00 to 1000 ° C. is applied.

The present invention is also directed to an oxide powder having a tetragonal perovskite structure obtained by the above-described production method. This oxide powder has a small particle size of 0.05 to 0.15 μm.

In the above oxide powder having a tetragonal perovskite structure, the a-axis of the perovskite structure and c
The c / a axis ratio, which is the ratio of the axes, is preferably 1.003 or more.

The oxide powder having a tetragonal perovskite structure has a general formula: (Ba _1-x Ca _x ) Ti
It is advantageously applied to oxide powders represented by O ₃ (where 0 ≦ x ≦ 0.15).

The present invention is also directed to a dielectric ceramic obtained by sintering a powder mainly containing an oxide powder having a tetragonal perovskite structure as described above.

The present invention also relates to a laminated body including a plurality of laminated dielectric ceramic layers and an internal electrode formed along a specific interface between these dielectric ceramic layers, and a specific one of the internal electrodes. An external electrode formed on an outer surface of the multilayer body so as to be electrically connected to the multilayer ceramic capacitor. In this multilayer ceramic capacitor, the dielectric ceramic layer is composed of the above-mentioned dielectric ceramic.

In the multilayer ceramic capacitor according to the present invention, the internal electrode preferably contains a base metal as a conductive component.

In the multilayer ceramic capacitor according to the present invention, the thickness of the dielectric layer interposed between the internal electrodes is preferably set to 0.6 μm or less.

[0021]

FIG. 1 is a sectional view schematically showing a multilayer ceramic capacitor 1 according to an embodiment of the present invention.

The multilayer ceramic capacitor 1 has a laminated body 3 having a plurality of laminated dielectric ceramic layers 2, and first and second formed on the first and second end surfaces 4 and 5 of the laminated body 3, respectively. And two external electrodes 6 and 7.

Inside the laminate 3, first internal electrodes 8 and second internal electrodes 9 are alternately arranged. The first internal electrode 8 has a specific plurality of dielectric ceramic layers 2 between the dielectric ceramic layers 2 with each edge exposed to the first end face 4 so as to be electrically connected to the first external electrode 6. The second internal electrode 9 is formed along the interface, while the second internal electrode 9 is connected to the second external electrode 7 by connecting each edge to the second end face 5.
Are formed along a plurality of specific interfaces between the dielectric ceramic layers 2 in a state where the dielectric ceramic layers 2 are exposed.

If necessary, the external electrodes 6 and 7
Are coated with first plating layers 10 and 11 made of Ni, Cu, Ni-Cu alloy, and the like, respectively. Further, on these first plating layers 10 and 11, second Plating layers 12 and 13
May be formed.

In such a laminated ceramic capacitor 1, the dielectric ceramic layer 2 provided in the laminated body 3
Is composed of a dielectric ceramic obtained by sintering a powder mainly containing an oxide powder having a tetragonal perovskite structure according to the present invention. The details of the oxide powder having the tetragonal perovskite structure and the method for producing the same will be described later.

In order to form the internal electrodes 8 and 9, a conductive paste containing, for example, Pt, a Pd-Ag alloy, Ni or the like as a conductive component is used. However, a base metal such as Ni is used in terms of cost. It is desirable.

The external electrodes 6 and 7 are, for example,
The Ag paste is applied which contains _{B 2 O 3 -Li 2 O-} SiO 2 -BaO -based glass frit, which may be formed by baking in a reducing atmosphere.

The above-mentioned materials for the internal electrodes 8 and 9 and the external electrodes 6 and 7 are not particularly limited. For example, the same material as the internal electrodes 8 and 9 can be used for forming the external electrodes 6 and 7.

The oxide powder having a tetragonal perovskite structure, which is a raw material powder for the dielectric ceramic constituting the dielectric ceramic layer 2 described above, is obtained by mixing the oxide powder having a cubic perovskite structure synthesized by a wet method. , At a pressure of 6 × 10 ³ Pa or less.

The wet method described above includes, for example,
Although a hydrolysis method and a hydrothermal synthesis method are known, industrially, it is preferable to use a hydrolysis method having higher productivity.

As described above, in performing the heat treatment,
When a low pressure of 6 × 10 ³ Pa or less is applied, undecomposed products and by-products of hydroxyl groups and raw material salts remaining on the surface and inside of the oxide powder having a cubic perovskite structure synthesized by a wet method are more effectively removed. Since the oxide powder can be removed at a low temperature, grain growth can be suppressed, and an oxide powder having a fine-grained tetragonal perovskite structure can be obtained.

When the pressure during the heat treatment is higher than 6 × 10 ³ Pa, the c / a axis ratio, which is the ratio of the a-axis to the c-axis of the perovskite structure in the obtained oxide powder having a tetragonal perovskite structure, is small. And the particle size increases, which is not preferred.

In order to reduce the particle diameter of the oxide powder having a tetragonal perovskite structure obtained by heat treatment, the particle diameter of the oxide powder having a cubic perovskite structure before heat treatment must be reduced. Is valid. Therefore, the particle diameter of the oxide powder having a cubic perovskite structure synthesized by a wet method,
It is preferably in the range of 0.01 to 0.1 μm.

When a pressure of 6 × 10 ³ Pa or less is applied to heat-treat the oxide powder having a cubic perovskite structure, undecomposed hydroxyl groups and raw material salts remaining on the surface and inside of the oxide powder are treated. As described above, it is not necessary to apply such a high temperature to remove substances and by-products, and preferably, in this heat treatment step, 600 to 1
Temperatures in the range of 000 ° C. apply.

When the heat treatment temperature is lower than 600 ° C.,
Not only does the decomposition of undecomposed products and by-products of hydroxyl groups and raw material salts not sufficiently proceed, but also the c / a axis ratio may not be increased. On the other hand, when the temperature exceeds 1000 ° C., the tetragonal perovskite structure Grain growth and sintering of particles of an oxide powder having the following progress, and therefore, the particle diameter may be increased.

The temperature and time for performing the heat treatment are as follows.
The decomposition temperature of undecomposed products and by-products of hydroxyl groups and raw material salts remaining on the surface and inside varies depending on the raw materials used in the synthesis of the oxide powder having a cubic perovskite structure by a wet method, the pressure during heat treatment, and the like. Therefore, it is not particularly limited. However, it is preferable that the optimum conditions for the temperature and time for performing such a heat treatment be determined in advance based on thermal analysis under a low pressure.

When heat treatment is performed under the same pressure using the same wet synthetic powder, the particle size of the obtained oxide powder having a tetragonal perovskite structure increases as the heat treatment temperature increases. However, it has been found that the c / a axis ratio is larger.

If an oxide powder having a tetragonal perovskite structure is obtained under the preferable conditions described above, a powder having a particle diameter of 0.05 to 0.15 μm can be obtained.

According to the oxide powder having a tetragonal perovskite structure thus obtained, the c / a axis ratio can be made 1.003 or more.
A dielectric ceramic exhibiting sufficient ferroelectricity as a multilayer ceramic capacitor can be obtained. When the c / a axis ratio is less than 1.003, the dielectric properties of the dielectric ceramic obtained using the oxide powder having a tetragonal perovskite structure are not sufficient for use as a multilayer ceramic capacitor.

More specifically, the oxide powder having a tetragonal perovskite structure produced according to the present invention comprises:
For example, (Ba _1-x Ca _x ) TiO ₃ (where 0 ≦
x ≦ 0.15).

The oxide powder having a tetragonal perovskite structure according to the present invention has an A / B ratio, which is the ratio of A-site atoms to B-site atoms, of not only one but also one according to the purpose of use. For example, 0.95 to 1.05,
An oxide powder having a tetragonal perovskite structure with a changed A / B ratio may be used. Particularly, in order to obtain an oxide powder having a non-reducible tetragonal perovskite structure,
The A / B ratio is preferably in the range of 1.00 to 1.035.

The dielectric ceramic obtained by firing the oxide powder having a tetragonal perovskite structure is obtained by adding a rare earth element, Zr, or Zr to the oxide powder having a tetragonal perovskite structure according to required characteristics. Mn, Mg, S
i, an additive such as Si, B, A
It may be a dielectric ceramic produced by adding a sintering aid containing l, Mg, Li or the like as a component.

In the following, the present invention is applied to a cubic barium titanate powder synthesized by a hydrolysis method, that is, Ba
_1.002 A specific example of producing a tetragonal barium titanate powder using TiO ₃ powder and (Ba _0.97 Ca _0.05 ) TiO ₃ powder, and lamination using the obtained tetragonal barium titanate. A specific example in which a ceramic capacitor is to be manufactured will be described.

In the description of these examples, Table 1
Referring to Tables 1 to 3, in Samples 1 to 3, Ba _1.002 TiO ₃ was used as cubic barium titanate for Samples 1 to 10, and (Ba _0.97 Ca _0.05 ) TiO ₂ was used for Samples 11 to 13. ₃ was used.

First, an oxide powder having a perovskite structure having a composition of Ba _1.002 TiO ₃ was synthesized by a hydrolysis method. The obtained oxide powder was prepared as shown in Tables 1 to 10
As shown in the above, the particle size is 12 to 52 nm,
The powder had a cubic perovskite structure containing many hydroxyl groups in the crystals having the perovskite structure.

Next, these powders were mixed with Samples 1 to 10 shown in Table 1.
Heat treatment at various pressures and heat treatment temperatures shown in
By having various particle diameters and c / a axis ratios
Ba _1.002TiO_ThreeA powder was obtained. By these heat treatments
Aggregation of the generated powder was broken after the heat treatment.

On the other hand, through the same process as described above, (B
a _0.97 Ca _0.05 ) An oxide powder having a perovskite structure having a composition of TiO ₃ was synthesized. As shown in Samples 11 to 13 of Table 1, the obtained oxide powder was a cubic powder having a particle size of 37 to 98 nm and containing many hydroxyl groups in crystals having a perovskite structure.

Next, these powders were mixed with Samples 11 to 1 in Table 1.
Heat treatment at various pressures and heat treatment temperatures shown in FIG. 3 has various particle sizes and c / a axis ratios (Ba
_0.97 Ca _0.05 ) TiO ₃ powder was obtained. Aggregation of the powder generated by these heat treatments was broken after the heat treatment.

The above-mentioned particle diameter is measured by observing a powder to be a sample with a scanning electron microscope. The c / a axis ratio was calculated by performing X-ray diffraction, performing a Rietveld analysis of the result, fitting an X-ray profile, and refining to obtain a lattice constant.

[0050]

[Table 1]

Next, as an additive to be added to the barium titanate powder after heat treatment as a raw material powder shown in Table 1, sintering containing Dy, Mg, Mn, and (Si—Ba) as main components is performed. Auxiliaries were provided. These additives were added to the barium titanate powder as alkoxide compounds soluble in the organic solvent, while the above-mentioned barium titanate as the raw material powder was dispersed in the organic solvent.

In order to make each of the above-mentioned additives soluble in an organic solvent, in addition to alkoxide, a compound such as acetylacetonate or metal soap may be used.

Next, the organic solvent in which the barium titanate powder and additives are dispersed is evaporated to dryness as described above,
Further, the organic component was removed by performing a heat treatment.

Next, an organic solvent such as a polyvinyl butyral-based binder and ethanol was added to each sample of the raw material powder to which each additive was added as described above, and the mixture was wet-mixed using a ball mill to obtain a ceramic slurry. Was prepared.

Next, this ceramic slurry was formed into a sheet by a doctor blade method, and the thickness was 0.8 μm.
Was obtained.

Next, a conductive paste containing Ni as a conductive component was printed on the ceramic green sheet to form a conductive paste film for forming internal electrodes of the multilayer ceramic capacitor.

Next, a plurality of ceramic green sheets were laminated so that the side from which the above-mentioned conductive paste film was drawn out was alternated, to obtain a green laminate.

Next, the green laminate is heated to a temperature of 350 ° C. in a nitrogen atmosphere to burn the binder, and then the H ₂ —N ₂ − at an oxygen partial pressure of 10 ⁻⁹ to 10 ⁻¹² MPa is applied. H
_It was fired at a temperature of 1150 ° C. for 2 hours in a reducing atmosphere composed of ₂ O gas. As a result, a laminated body including the sintered dielectric ceramic layer was obtained, and the above-mentioned conductive paste film was in a state of providing internal electrodes.

Next, B ₂ was placed on both end surfaces of the fired laminate.
An Ag paste containing an O ₃ —Li ₂ O—SiO ₂ —BaO-based glass frit is applied and baked at a temperature of 600 ° C. in a nitrogen atmosphere, whereby an external electrode electrically connected to the internal electrode is formed. Thus, a multilayer ceramic capacitor as a sample was completed.

The external dimensions of the multilayer ceramic capacitor thus obtained were as follows: a width of 5.0 mm and a length of 5.7.
mm, the thickness was 2.4 mm, and the thickness of the dielectric ceramic layer interposed between the internal electrodes was 0.5 μm. The number of effective dielectric ceramic layers was 5, and the area of the counter electrode per layer was 16.3 × 10 ⁻⁶ m ² .

Next, for each sample of the obtained multilayer ceramic capacitor, as shown in Table 2, “crystal grain size after firing”, “short defect occurrence rate”, “dielectric constant”, “dielectric loss” and The "specific resistance" was determined,

[0062]

[Table 2]

In Table 2, “crystal grain size after firing” means
The average crystal grain size of the dielectric ceramic constituting the dielectric ceramic layer included in the obtained multilayer ceramic capacitor was determined by chemically etching the cross-section polished surface of the laminate and observing it with a scanning electron microscope.

The “short defect occurrence rate” indicates the ratio of the number of samples having a short defect to the number of samples of the obtained multilayer ceramic capacitor.

As for “dielectric constant”, the capacitance (C) of a multilayer ceramic capacitor as a sample was measured according to JIS standard 5102 using an automatic bridge type measuring instrument, and the dielectric constant was determined from the obtained capacitance. (Ε) is calculated.

The “dielectric loss” (tan δ) is measured according to JIS standard 5102 using an automatic bridge type measuring instrument.

As for the “specific resistance”, an insulation resistance meter was used to apply a 5 V DC voltage to a sample laminated ceramic capacitor for 2 minutes to obtain an insulation resistance (R) at 25 ° C. Is calculated from

In Tables 1 and 2, those marked with an asterisk (*) are out of the scope of the present invention.

As shown in Table 1, according to Samples 2 to 13 within the scope of the present invention, cubic barium titanate powder having a particle diameter of 12 to 98 nm synthesized by the hydrolysis method was mixed with 6 × 10 ^3. Under a pressure of Pa or less,
By performing heat treatment at a heat treatment temperature in the range of ° C., tetragonal barium titanate powder having a particle size of 58 to 146 nm can be obtained, and the c / a axis ratio of these tetragonal barium titanate powders is set to 1.003 or more. be able to.

Therefore, if a dielectric ceramic layer provided in a multilayer ceramic capacitor is formed using such tetragonal barium titanate powder, even if the thickness of the dielectric ceramic layer is reduced to 0.5 μm,
As shown in Table 2, it is possible to provide a dielectric ceramic layer having a low short-circuit defect occurrence rate and exhibiting sufficient ferroelectricity.

On the other hand, according to Sample 1 outside the scope of the present invention, even if the particle diameter of the cubic barium titanate powder synthesized by the hydrolysis method is 6 × 1 exceeding × 10 ³ Pa
0 ⁴ since the applied pressure Pa, after the heat treatment, the particle size of the tetragonal barium titanate powder 160nm
Up to. Therefore, when a multilayer ceramic capacitor having a dielectric ceramic layer thickness of 0.6 μm is manufactured, a short-circuit defect occurrence rate is increased and a dielectric loss is increased.

Next, with respect to the multilayer ceramic capacitor according to Sample 8 shown in Tables 1 and 2, as shown in Table 3, “DC bias applied capacitance change rate”, “capacitance temperature change rate”, “dielectric breakdown voltage” "And" average life time "were evaluated.

[0073]

[Table 3]

In Table 3, “DC bias applied capacitance change rate” means the change rate of the capacitance when a DC bias of 3 kV / mm was applied to the sampled multilayer ceramic capacitor, It was obtained as a reference.

The “capacitance temperature change rate” is obtained by calculating the change rate of the capacitance with respect to the temperature change. The maximum value in the temperature range of −25 ° C. to + 85 ° C. based on the capacitance at 20 ° C. The rate of change (ΔC / C ₂₀ ) and the maximum rate of change (ΔC / C ₂₅ ) in the temperature range of −55 ° C. to + 125 ° C. based on the capacitance at 25 ° C. are shown.

The "dielectric breakdown voltage" is obtained by applying a DC voltage to the multilayer ceramic capacitor as a sample at a step-up speed of 100 V / sec, and determining a voltage at which the multilayer ceramic capacitor has broken down.

[0077] "average life time", the laminated ceramic capacitor serving as a sample, by applying a DC voltage of 5V at a temperature of 0.99 ° C., measured the time course of insulation resistance, the insulation resistance value is 10 ⁵ When it becomes Ω or less, it is judged as failure,
The average life time was evaluated.

As can be seen from Table 3, according to the sample 8 within the scope of the present invention, a highly reliable multilayer ceramic capacitor can be obtained.

[0079]

As described above, according to the method for producing an oxide powder having a tetragonal perovskite structure according to the present invention, when the oxide powder having a cubic perovskite structure synthesized by a wet method is subjected to heat treatment, 6 × 10
^Since a relatively low pressure of ³ Pa or less is applied, hydroxyl groups and raw materials remaining on the surface and inside of the oxide powder having a cubic perovskite structure even when heat-treated at a relatively low temperature in the range of, for example, 600 to 1000 ° C. Undecomposed salts and by-products of the salt are efficiently removed, so that grain growth is suppressed, the particle size is as small as 0.05 to 0.15 μm, and the c / a axis ratio is 1.003 or more. Thus, an oxide powder having a tetragonal perovskite structure and exhibiting sufficient ferroelectricity can be obtained.

Therefore, when the dielectric ceramic layer in the multilayer ceramic capacitor is formed by using the oxide powder having the tetragonal perovskite structure, the thickness of the dielectric ceramic layer is reduced to, for example, 0.6 μm or less. In addition, a multilayer ceramic capacitor can be manufactured without any problem, and therefore, a small-sized and large-capacity multilayer ceramic capacitor can be realized with high reliability.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a multilayer ceramic capacitor 1 according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multilayer ceramic capacitor 2 Dielectric ceramic layer 3 Multilayer body 4,5 End surface 6,7 External electrode 8,9 Internal electrode

Continued on the front page F term (reference) 4G031 AA04 AA06 AA11 BA09 CA01 CA03 CA04 GA03 5E001 AB03 AC09 AD00 AE00 AE02 AE03

Claims (10)

[Claims] A step of synthesizing an oxide powder having a cubic perovskite structure by a wet method; and
Heat treating under a pressure of 6 × 10 ³ Pa or less, the method for producing an oxide powder having a tetragonal perovskite structure. 2. The oxide powder having a cubic perovskite structure synthesized by the wet method has a particle diameter of 0.1.
The method for producing an oxide powder having a tetragonal perovskite structure according to claim 1, which has a diameter of from 0.01 to 0.1 μm. 3. The method according to claim 1, wherein the heat-treating step comprises:
The method for producing an oxide powder having a tetragonal perovskite structure according to claim 1 or 2, wherein a temperature in a range of 1000 ° C is applied. 4. A particle obtained by the production method according to claim 1 and having a particle diameter of 0.05 to 0.1.
An oxide powder having a tetragonal perovskite structure of 5 μm. 5. The oxide powder having a tetragonal perovskite structure according to claim 4, wherein the c / a axis ratio, which is the ratio of the a-axis to the c-axis of the perovskite structure, is 1.003 or more. 6. General formula: (Ba _1-x Ca _x ) TiO
_The oxide powder having a tetragonal perovskite structure according to claim 4 or 5, represented by ₃ (where 0 ≦ x ≦ 0.15). 7. A dielectric ceramic obtained by sintering a powder containing the oxide powder having a tetragonal perovskite structure according to claim 4 as a main component. 8. A laminate comprising a plurality of laminated dielectric ceramic layers and an internal electrode formed along a specific interface between said dielectric ceramic layers, and electrically connected to a specific one of said internal electrodes. An external electrode formed on an outer surface of the multilayer body so as to be connected to the multilayer ceramic capacitor, wherein the dielectric ceramic layer is made of the dielectric ceramic according to claim 7. 9. The multilayer ceramic capacitor according to claim 8, wherein said internal conductor includes a base metal as a conductive component. 10. The multilayer ceramic capacitor according to claim 8, wherein said dielectric ceramic layer interposed between said internal electrodes has a thickness of 0.6 μm or less.