WO2008066119A1

WO2008066119A1 - Dielectric ceramic and capacitor

Info

Publication number: WO2008066119A1
Application number: PCT/JP2007/073060
Authority: WO
Inventors: Katsuyoshi Yamaguchi; Ryota Kuki; Hiroaki Mino
Original assignee: Kyocera Corporation
Priority date: 2006-11-29
Filing date: 2007-11-29
Publication date: 2008-06-05

Abstract

Disclosed is a dielectric ceramic comprising crystal grains mainly composed of barium titanate. This dielectric ceramic contains 0.01-0.06 mole of magnesium in terms of MgO, 0.0007-0.03 mole of yttrium in terms of Y2O3 and 0.0002-0.03 mole of manganese in terms of MnO per 1 mole of barium constituting the barium titanate, while containing 4.2-33.3 parts by mass of niobium in terms of Nb2O5 per 100 parts by mass of the barium titanate. The crystal grains have an average particle size of 0.05-0.25 μm. Also disclosed is a capacitor composed of a laminate having a conductive layer and a dielectric layer made of such a dielectric ceramic.

Description

Specification

Dielectric porcelain and capacitor

Technical field

TECHNICAL FIELD [0001] The present invention relates to a dielectric ceramic formed of crystal particles mainly composed of barium titanate and a capacitor using the dielectric ceramic for a dielectric layer.

Background art

[0002] At present, digital terrestrial broadcasting is about to be deployed in the near future when the spread of digital electronic devices such as mobile computers and mobile phones is remarkable. Digital electronic devices that are receivers for terrestrial digital broadcasting include liquid crystal displays and plasma displays. Many digital LSIs are used in these digital electronic devices.

[0003] For this reason, many bypass capacitors are mounted on power supply circuits constituting these digital electronic devices such as liquid crystal displays and plasma displays. The capacitor used here is a multilayer ceramic capacitor having a high dielectric constant (for example, see Patent Document 1) when a high capacitance is required. On the other hand, when importance is attached to temperature characteristics even at a low capacity, a temperature-compensated multilayer ceramic capacitor (see, for example, Patent Document 2) having a small capacitance change rate is employed.

[0004] However, in the high dielectric constant multilayer ceramic capacitor disclosed in Patent Document 1, the dielectric layer is composed of crystal grains of dielectric ceramics having ferroelectricity, so that the temperature change of the relative dielectric constant changes. There was a problem that the rate was large and the hysteresis in the electric field dielectric polarization characteristics was large.

[0005] Further, in the capacitor in which the dielectric layer disclosed in Patent Document 1 is formed using a ferroelectric dielectric ceramic, it is easy to generate noise noise due to electrically induced distortion on the power supply circuit. For this reason, such noise caused by capacitors has been an obstacle to the use of plasma displays.

[0006] On the other hand, in a temperature-compensated monolithic ceramic capacitor, since the dielectric ceramic constituting the dielectric layer is paraelectric, hysteresis in electric field dielectric polarization characteristics is small. This For this reason, although there is an advantage that the electrical induction distortion peculiar to ferroelectricity does not occur, there is a problem that the capacity as a bypass capacitor is not satisfied because the dielectric constant of the dielectric ceramic is low and the storage capacity is low. .

[0007] Patent Document 1: JP 2001-89231 A

Patent Document 2: JP 2001-294481 A

Disclosure of the invention

Problems to be solved by the invention

The problem to be solved by the present invention is to provide a dielectric ceramic exhibiting a temperature characteristic of a high dielectric constant and a stable relative dielectric constant, and a capacitor using the dielectric ceramic.

Means for solving the problem

[0009] The dielectric ceramic of the present invention is composed of crystal grains mainly composed of barium titanate and a grain boundary phase formed between the crystal grains, and the dielectric porcelain constituting the barium titanate. 1 mol of magnesium, 0.01 to 0.06 mol of magnesium in terms of MgO, 0007 to 0.03 monolayers in terms of YO, and 0.00002 to 0.03 monoles of manganese in terms of MnO In addition, with respect to 100 parts by mass of the barium titanate, niobium is contained in an amount of 4.2-33.3 parts by Nb 2 O, and the average grain size of the crystal grains is 0.05-0.25 m is the special feature.

In the dielectric ceramic according to the present invention, with respect to 1 mol of barium constituting the barium titanate, the magnesium is converted to MgO in an amount of 0.017 to 0.06 mol, and the yttrium is converted to an YO in the range of 0.005 to 0.00. 01 Monole and manganese containing MnO in the form of 0.01--0.03 monole and niobium in NbO equivalent to 100 parts by mass of barium titanate.

3-15. It is preferable that the molar ratio of titanium to 1 mole of barium contained in 6 parts by mass and constituting the barium titanate is 0.97-0.98.

[0010] In the dielectric ceramic according to the present invention, with respect to 100 parts by mass of the barium titanate, 0.73-6.3 parts by mass of silicon in terms of SiO and 0.31-2. It is desirable to include part by mass.

In the dielectric ceramic according to the present invention, with respect to 1 mol of barium constituting the barium titanate, the magnesium is converted to MgO in terms of 0.017 to 0.06 mol, and the yttrium is converted to YO. In addition, it contains 0.01.01-.01 monole, and the above manganese contains 0.01-0.0.03 monole in terms of MnO, and the niobium in terms of NbO in terms of 100 parts by mass of barium titanate.

twenty five

3-15. Containing 6 parts by mass, and with respect to 100 parts by mass of barium titanate, silicon is 0.73--3.13 parts by mass in terms of SiO and boron is 0.3-equivalent in terms of BO. It is desirable that the molar ratio of titanium to 1 mole of barium contained in parts by mass and constituting the barium titanate is 0 · 97-0.98.

[0011] In the dielectric ceramic according to the present invention, with respect to 100 parts by mass of the barium titanate, 0.73 to 6.3 parts by mass of silicon in terms of SiO and 0.31 to 2. It is desirable to contain 1 part by mass.

In the dielectric ceramic according to the present invention, with respect to 1 mol of barium constituting the barium titanate, the magnesium is converted into MgO in terms of 0.017 to 0.06 mol, and the yttrium is converted to Y 2 O.

2 3 is calculated as 0.0015—0.01 monole, and manganese contains 0.01—0.03 monole in terms of MnO, and niobium in terms of Nb 2 O with respect to 100 parts by mass of the barium titanate. 6

twenty five

3-15. Containing 6 parts by mass, and with respect to 100 parts by mass of the barium titanate, 0.73-3.13 parts by mass of silicon in terms of SiO and 0.31-1. It is desirable that the molar ratio of titanium to 1 part of barium contained in 04 parts by mass and constituting the barium titanate is 0 · 97-0.98.

[0012] The capacitor of the present invention is composed of a laminate of a dielectric layer made of a dielectric ceramic and a conductor layer, and the dielectric ceramic has crystal grains mainly composed of barium titanate, and It consists of a grain boundary phase formed between crystal grains, and with respect to 1 mol of barium that constitutes the barium titanate, magnesium is 0.01 to 0.06 mol in terms of MgO and yttrium is 0.0 in terms of YO. 0007—0.03 Monole, Manganese containing 0.00002—0.03 Monole in terms of MnO

Three

In addition, niobium is converted to NbO with respect to 100 parts by mass of the barium titanate.

2-5 and 4. 2-33.3 parts by mass, and the average grain size of the crystal grains is 0.05-0.25 ^ 111.

In the capacitor of the present invention, the dielectric layer has a magnesium content of 0.017 to 0.06 mol in terms of MgO and the yttrium in terms of YO in terms of 1 mol of barium constituting the barium titanate. ~ 0 · 01 monole, manganese is converted to MnO 0 · 0 ∼ 0 · 03 In addition to 100 parts by mass of the barium titanate, the niobium is contained in the amount of 6.3-15.6 parts by mass in terms of Nb ₂ 0, and the titanium is contained in 1 mol of barium constituting the barium titanate. It is desirable that the molar ratio is 0 · 97-0.98.

[0013] The dielectric porcelain may further include 0.73 to 6.3 parts by mass of silicon in terms of SiO and 0.3 to 0.3 in terms of boron with respect to 100 parts by mass of the barium titanate;! To 2.1. It is desirable to contain part by mass.

In the capacitor of the present invention, the dielectric layer has a magnesium content of 0.017 to 0.06 mol in terms of MgO and yttrium in terms of YO with respect to 1 mol of barium constituting the barium titanate. ~ 0 · 01 monole, containing manganese in 0 · 0 to 0 · 03 mol in terms of ΜηΟ, and niobium in terms of NbO with respect to 100 parts by mass of barium titanate 6.3-15.6 mass In addition to 100 parts by weight of barium titanate, 0.73 to 3.13 parts by weight of silicon in terms of SiO and 0.31 to 1.04 parts by weight of boron in terms of BO, and It is desirable that the molar ratio of titanium to 1 mol of barium constituting barium titanate is 0.97-0.98.

[0014] In the dielectric ceramic, with respect to 100 parts by mass of the barium titanate, 0.73-6.3 parts by mass of silicon in terms of SiO and 0.31-2.1 parts by mass of lithium in terms of Li 2 O It is desirable to contain a part.

In the capacitor of the present invention, the dielectric layer has a magnesium content of 0.017 to 0.06 mol in terms of MgO and yttrium in terms of YO with respect to 1 mol of barium constituting the barium titanate. ~ 0 · 01 monole, containing manganese in 0 · 0 to 0 · 03 mol in terms of ΜηΟ, and niobium in terms of NbO with respect to 100 parts by mass of barium titanate 6.3-15.6 mass Further, for 100 parts by mass of the barium titanate, 0.73 to 3.13 parts by mass of silicon in terms of SiO and 0.3 to 0.3 parts of lithium in terms of Li 2 O;! To 1.04 parts by mass It is desirable that the molar ratio of titanium to 1 mol of barium constituting the barium titanate is 0 · 97−0.98.

The invention's effect

[0015] According to the dielectric ceramic of the present invention, the temperature change rate of the relative permittivity is smaller than that of a conventional dielectric ceramic having a ferroelectric property, and compared to a conventional dielectric ceramic having a paraelectric property. High It is a dielectric constant, has a temperature characteristic of a stable relative dielectric constant, and can reduce spontaneous polarization.

In particular, when silicon and boron are contained at a specific ratio, liquid phase sintering can be performed, and firing at a low temperature (1100 to 1250 °) becomes possible.

Further, even when silicon and lithium are contained at a specific ratio, liquid phase sintering can be performed, and firing at a low temperature (1100 to 1250 ° C.) becomes possible.

[0016] According to the capacitor of the present invention, the dielectric layer is composed of a dielectric ceramic having a high dielectric constant and a stable relative dielectric constant and having a low spontaneous polarization. In addition, a capacitor having a high capacity and stable capacitance-temperature characteristics can be formed. When this capacitor is used in a power supply circuit, it is possible to suppress the generation of noise noise caused by electrically induced distortion.

Brief Description of Drawings

FIG. 1 is a schematic cross-sectional view showing a capacitor according to first to third embodiments of the present invention.

FIG. 2 is a graph showing the X-ray diffraction results of Sample No. I-4 in Example I.

FIG. 3 is a drawing showing the rate of change in relative permittivity of Sample Nos. I-4, 33 and 34 in Example I.

FIG. 4 is a graph showing the dielectric polarization (V—Q) characteristics of Sample No. I-4 in Example I.

FIG. 5 is a graph showing the X-ray diffraction results of Sample No. II-4 in Example II.

FIG. 6 is a graph showing the X-ray diffraction results of Sample No. Ill-4 in Example III.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a dielectric ceramic and a capacitor according to a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the capacitor of this embodiment. The dielectric ceramic of the present embodiment is mainly composed of barium titanate, and contains magnesium, yttrium, manganese and niobium. The content of magnesium is MgO equivalent to 1 mol of barium. Containing 0.01 to 0.06 mole of yttrium in the range of 0007 to 0.03 monole in terms of YO and manganese in the range of 0.002 to 0.03 monole in terms of MnO and 100 parts by mass of the barium titanate. Niobium converted to Nb O In 4.2 to 33.3 parts by mass.

In addition, the dielectric ceramic according to the present embodiment includes crystal grains mainly composed of barium titanate and a grain boundary phase formed between the crystal grains. The grain boundary phase is an amorphous or other crystalline phase caused by the subcomponents such as magnesium, yttrium, manganese and niobium, and is formed by liquid phase sintering of barium titanate and these subcomponents. Is. In this embodiment, the average particle size of the crystal particles is 0.05 to 0.25 m.

[0020] When the dielectric ceramic is in the above composition and particle size range, the relative dielectric constant at room temperature (25 ° C) described later is 250 or more, the relative dielectric constant at 125 ° C is 230 or more, and 25 ° C. The temperature coefficient of relative dielectric constant between ˜125 ° C (( _ε -ε) / ε (125− 25)) in absolute value 100

125 25 25

0 can be a chi 10- ⁶ / ° c or less, an electric field - to be able to form small dielectric ceramic hysteresis in the dielectric polarization characteristics / it is advantageous cormorants.

[0021] The dielectric ceramic according to the present embodiment is obtained by dissolving magnesium, yttrium, manganese, and niobium in barium titanate. In addition, magnesium, yttrium, manganese, and niobium are solid-dissolved in barium titanate, which has a tetragonal crystal structure and strong conductivity, and crystal grains mainly composed of barium titanate in which these components are dissolved. By setting the average particle size of the particles in the range of 0.05 to 0. 25 m, the crystal structure of the crystal particles can be mainly composed of a cubic system. As a result, the ferroelectricity due to the tetragonal crystal structure is reduced, the paraelectricity can be increased, and the spontaneous polarization can be reduced by increasing the paraelectricity.

[0022] Further, by making the crystal structure of the crystal grains mainly composed of barium titanate into a crystal structure mainly composed of a cubic system, a curve indicating the rate of change of relative permittivity is 55 ° C to 125 ° C; It becomes flat in the temperature range of ° C, and the hysteresis in the electric field dielectric polarization characteristics becomes small. Therefore, even when the relative permittivity is 250 or more, it is possible to obtain a dielectric ceramic having a small relative permittivity temperature coefficient.

[0023] That is, when a predetermined amount of magnesium, yttrium, and manganese is contained in barium titanate within the above-described range, a Curie temperature of 25 ° C or higher is exhibited, and the temperature coefficient of relative permittivity is a positive value. When the niobium is further added to the dielectric ceramic exhibiting such a dielectric property S, and the dielectric ceramic exhibiting such dielectric characteristics, a greater effect can be obtained, and the temperature coefficient of the relative dielectric constant can be obtained. The temperature characteristic can be flattened by reducing the number. In this case, the curve indicating the rate of change of the relative dielectric constant has two peaks centered at 25 ° C in the temperature range of 155 ° C to 125 ° C.

Here, niobium has a function of suppressing the coarsening of crystal grains mainly composed of barium titanate, and niobium is converted into Nb 2 O in terms of Nb 2 O with respect to 100 parts by mass of barium titanate. . Contains 3 parts by mass.

That is, when the content of niobium with respect to 100 parts by mass of barium titanate is less than 4.2 parts by mass in terms of Nb 2 O, the dielectric constant of the dielectric ceramic is high, but the temperature coefficient of the relative dielectric constant is large. It will be a thing. On the other hand, if the niobium content relative to 100 parts by weight of barium titanate is more than 33.3 parts by weight in terms of NbO, the relative dielectric constant at 25 ° C will be lower than 250.

In addition, the relative dielectric constant at 125 ° C. is less than 230.

[0026] The contents of magnesium, yttrium, and manganese are as follows. Magnesium is converted to Mg · O · 01—0.06 mol, and yttrium is converted to Y 2 O in terms of 1 · mol.

.03 Monole and manganese are contained in MnO as 0.00002—0.03 monole.

[0027] That is, when the magnesium content relative to 1 mol of norm is less than 0.01 Mole or more than 0.06 mol in terms of MgO, the temperature coefficient of the relative permittivity of the dielectric ceramic increases. . In addition, the yttrium content per mole of norium is 0.000 in terms of Y 2 O.

If it is less than 07 moles or more than 0.03 moles, the dielectric constant of the dielectric ceramic is high, but the temperature coefficient of the relative permittivity becomes large. In addition, if the content of mangan per mol of barium is less than 0.002 monole in MnO, or more than 0.03 monole, the temperature coefficient of the dielectric constant of the dielectric ceramic is large. Become.

Furthermore, the dielectric ceramic according to the present embodiment has an average particle size force of crystal particles mainly composed of barium titanate.

That is, by setting the average particle size of the crystal particles mainly composed of barium titanate to 0.05-0.25 μm, the crystal particles mainly composed of barium titanate have a cubic system. It has a crystalline structure as the main component, and has a small hysteresis in the electric field dielectric polarization characteristics and can exhibit characteristics close to paraelectricity. On the other hand, when the average particle size of the crystal particles mainly composed of barium titanate is smaller than 0.05 in, the contribution of orientation polarization is lost, so that the dielectric The relative dielectric constant of the ceramic body is reduced. On the other hand, when the average grain size of the crystal grains is larger than 0.25 111, a tetragonal crystal phase is observed in the X-ray diffraction measurement, and the temperature coefficient of the dielectric constant of the dielectric ceramic is high. growing.

[0030] Note that the crystal structure mainly composed of cubic system means that the intensity of diffraction peak of (110) plane which is the strongest peak of cubic system barium titanate is larger than the intensity of diffraction peak of different phase. State.

[0031] Further, in this embodiment, in the electric field dielectric polarization characteristics, the average charge of crystal grains is more preferably 0.14-0.18 111 in that the polarization charge at 0V can be ²⁰ nC / cm ² or less. I want it.

[0032] Further, preferable niobium, magnesium, yttrium and manganese contents are as follows. Magnesium in terms of MgO is 0 · 17-17.06 monole, and yttrium is in the YO equivalent of 0.005–0.01. Mono and Manganese in MnO conversion 0 · 01 ~ 0.03 Mono

twenty three

And niobium in terms of NbO with respect to 100 parts by mass of barium titanate 6.3-15. 6

twenty five

In addition to the range of parts by mass, the molar ratio of titanium to 1 mol of barium is 0 · 97-0.98. Dielectric porcelain in this range has a relative permittivity at 25 ° C of 400 or more, a relative permittivity at 125 ° C of 380 or more, and a relative permittivity temperature coefficient of 400 X 10-6 / ° C or less in absolute value. It becomes possible to do.

[0033] Here, the average particle diameter of the crystal particles mainly composed of barium titanate is determined by polishing a fracture surface of a sample having a dielectric ceramic force after firing, as described later, and then using a scanning electron microscope. This is a value obtained by taking a picture of the internal structure using the image, processing the contours of the crystal grains shown in the picture, treating each particle as a circle, determining its diameter, and averaging. More specifically, the magnification of the photograph is approximately 30000 times, the number of observation points is 3 for each sample, and the average value is obtained.

In addition, the relative dielectric constant at 25 ° C. and 125 ° C. is determined by using a dielectric ceramic force sample formed into a predetermined pellet shape and having a conductor film formed on the surface, as described later. Using a meter 4284A (manufactured by HP), measure the capacitance at a frequency of 1.0 kHz, an input signal level of 1.0 V, and temperatures of 25 ° C and 125 ° C. This is a value calculated from the area of the conductor film. Temperature coefficient of relative permittivity between 25 ° C and 125 ° C The numbers are calculated by applying the relative permittivity at 25 ° C and 125 ° C to the following formula (1).

[0035] Temperature coefficient of relative permittivity = · · '(1) ε _{2 5} X (1 2 5-2 5)

Relative permittivity at £ _{2 5} : 2 5 ¾

ί! 2 ₅ : relative permittivity at 1 25 ° C

Next, a method for manufacturing the dielectric ceramic according to the present embodiment will be described.

First, BaCO powder, TiO powder, MgO powder, Y 2 O powder, and manganese carbonate (MnCO 3) powder each having a purity of 99% or more are used as the raw material powder. These raw material powders are based on 1 mole of barium constituting barium titanate, MgO is 0.001-0.06 mono, Y0 is 0.007-0.03 monole, and MnCO is 0.00. 0002—0.03 Harm of monole 'J combination.

[0037] Next, the mixture of the raw material powders described above is wet-mixed and dried, and then calcined at a temperature of 900 to 11100 ° C to prepare a calcined powder, and the calcined powder is pulverized. . At this time, the dielectric structure with a high dielectric constant that maintains the temperature characteristics of the relative dielectric constant close to normal dielectricity is obtained by growing the grains so that the crystal structure of the calcined powder is mainly cubic. It becomes possible to obtain porcelain.

The average particle size of the calcined powder is preferably 0.04-0 .; 1 m. Thereby, the expression of ferroelectricity can be suppressed in the calcined powder. As will be described later, the average particle diameter of the calcined powder is determined by dispersing the calcined powder on a sample stage for an electron microscope, taking a picture with a scanning electron microscope, and The contour is image-processed, each powder is regarded as a circle, its diameter is obtained, and averaged.

[0038] Next, Nb 2 O powder is mixed at a ratio of 4.0 to 32 parts by mass with respect to 100 parts by mass of the calcined powder. Thereafter, the mixed powder is formed into a pellet and fired in the air at a temperature range of 1150 ° C. to 1250 ° C., whereby the dielectric ceramic according to the present embodiment can be obtained. Here, when the firing temperature is lower than 1150 ° C., the growth of the crystal grains and densification are suppressed, so that the density of the dielectric ceramic becomes low. On the other hand, the firing temperature is higher than 1250 ° C In such a case, the crystal grains of the dielectric ceramic may grow too much.

[0039] Next, the capacitor of this embodiment will be described. Using the dielectric porcelain described above

The following capacitors can be formed.

That is, the capacitor of this embodiment is one in which external electrodes 12 are provided at both ends of a capacitor body 10 as shown in FIG. The capacitor body 10 is composed of a multilayer body 1 in which a plurality of dielectric layers 13 and a plurality of conductor layers 14 that are internal electrode layers are alternately laminated. The dielectric layer 13 is formed by the dielectric ceramic of the present embodiment described above. That is, the dielectric layer 13 exhibits a temperature characteristic of a high dielectric constant and a stable relative dielectric constant, and by applying the dielectric ceramic having a small spontaneous polarization, the capacitance is higher than that of a conventional capacitor and the capacitance temperature characteristic is more stable. It becomes a simple capacitor. For this reason, when this capacitor is used in a power supply circuit, it is possible to suppress the generation of noise noise caused by electrically induced distortion.

[0041] The thickness of the dielectric layer 13 is preferably 1 to 30 m. In particular, if the thickness of the dielectric layer 13 is not more than m, there is an advantage that the capacitance of the capacitor can be increased by making the dielectric layer 13 thinner.

[0042] Base layer 14 such as Ni or Cu is desirable because conductor layer 14 can suppress manufacturing costs even when the number of layers is increased, and Ni is more advantageous in terms of simultaneous firing with dielectric layer 13. desirable. The conductor layer 14 preferably has an average thickness of 1 m or less.

When producing such a capacitor, first, the above-mentioned mixed powder is formed into a green sheet. Next, a conductor paste to be the conductor layer 14 is prepared, printed on the surface of the green sheet, laminated and fired to form the laminate 1. Thereafter, a conductor paste is further printed on both end faces of the laminate 1 and fired to form the external electrode 12, whereby the capacitor of this embodiment can be obtained.

Next, a second embodiment of the present invention will be described. The dielectric ceramic according to the present embodiment is mainly composed of barium titanate and contains magnesium, yttrium, manganese, niobium, silicon, and boron. Nesym is converted to MgO as 0 · 01—0.06 mol, Yttrium is converted to YO as 0 · 0007—0. 03 mol and manganese in an amount of 0 · 0002–0.03 mol in terms of MnO, and 4.2 to 33.3 parts by mass of niobium in terms of Nb 2 O with respect to 100 parts by mass of the barium titanate.

twenty five

Is 0.73-6.3 parts by mass in terms of SiO and 0.31-2.1 parts by mass of boron in terms of B 2 O.

In addition, the dielectric ceramic according to the present embodiment includes crystal particles mainly composed of barium titanate and a grain boundary phase formed between the crystal particles, and the average particle size of the crystal particles is 0. 05 to 0.25 μm.

[0046] When the dielectric ceramic is in the above composition and particle size range, as in the first embodiment, the relative dielectric constant at 25 ° C is 250 or more, the relative dielectric constant at 125 ° C is 230 or more, and 2 5 ° C ~; the temperature coefficient of relative permittivity between 125 ° C ((ε-ε) / ε (125− 25))

125 25 25

Absolute value can below 1000 X 10- ⁶ / ° c, the field - dielectric polarization characteristics in the hysteresis small les, if capable of forming a dielectric ceramic Les is advantageous cormorants.

[0047] Such a dielectric ceramic according to the present embodiment includes magnesium, yttrium, manganese and niobium in solid solution in barium titanate, and silicon and boron are contained in the grain boundary phase.

[0048] In addition, magnesium, yttrium, manganese, and niobium are solid-dissolved in barium titanate having a tetragonal crystal structure and ferroelectricity, and the average particle size of crystal grains mainly composed of barium titanate is determined. By setting the range of 0.05 to 0. 25 m, the crystal structure of the crystal grains can be mainly composed of cubic system. As a result, the ferroelectricity due to the tetragonal crystal structure is lowered, the paraelectricity can be increased, and the spontaneous polarization can be reduced by increasing the paraelectricity.

[0049] Further, by changing the crystal structure of the crystal grains mainly composed of barium titanate to a crystal structure mainly composed of a cubic system, the rate of change of the relative dielectric constant is the same as in the first embodiment. The curve showing the curve becomes flat in the temperature range of -55 ° C to 125 ° C, and the hysteresis in the electric field-dielectric polarization characteristics is reduced. Therefore, it is possible to obtain a dielectric ceramic having a low relative dielectric constant temperature coefficient even though the relative dielectric constant is 250 or more.

[0050] That is, when a predetermined amount of magnesium, yttrium, and manganese is contained in barium titanate within the above-described range, a Curie temperature of 25 ° C or higher is exhibited, and the temperature coefficient of relative permittivity is The dielectric ceramic has a positive dielectric characteristic. However, when the dielectric ceramic having such a dielectric characteristic is further incorporated with niobium, silicon, and boron, the temperature of the relative dielectric constant is increased. The coefficient can be reduced and the temperature characteristics can be flattened. In this case, the curve indicating the rate of change of the relative dielectric constant has two peaks centered at 25 ° C in the temperature range of -55 ° C to 125 ° C.

[0051] In particular, according to the present embodiment, by containing silicon and boron in a specific ratio, liquid phase sintering can be performed, and baking at a low temperature (1100 to 1250 ° C) becomes possible.

Here, each of the oxides of niobium, silicon, and boron has a function of suppressing the coarsening of the crystal grains mainly composed of barium titanate, and two nibbs with respect to 100 parts by mass of barium titanate. Is 4.2-33.3 parts by mass in terms of Nb 2 O, silicon is 0.73-6.3 parts by mass in terms of SiO, and boron is 0.3 in terms of BO;! -2.1 parts by mass.

That is, when the content of niobium with respect to 100 parts by mass of barium titanate is less than 4.2 parts by mass in terms of Nb 0, the dielectric constant of the dielectric ceramic is high, but the temperature coefficient of the relative permittivity is large. It will be a thing. On the other hand, if the niobium content relative to 100 parts by weight of barium titanate is more than 33.3 parts by weight in terms of NbO, the relative dielectric constant at 25 ° C will be lower than 250.

In addition, the relative dielectric constant at 125 ° C. is less than 230.

[0054] Further, the silicon content relative to 100 parts by mass of barium titanate is less than 0.73 parts by mass in terms of SiO, or the boron content is less than 0.31 parts by mass in terms of B 2 O.

In the case of V, in the case of firing at a low temperature (1100-; 1250 ° C), the dielectric porcelain cannot be densified and the relative dielectric constant may be lowered.

[0055] On the other hand, when the silicon content relative to 100 parts by mass of barium titanate is more than 6.3 parts by mass in terms of SiO, or when boron is more than 2.1 parts by mass in terms of BO, dielectric The relative permittivity of the body porcelain may decrease and the temperature coefficient of the relative permittivity may increase.

[0056] The contents of magnesium, yttrium, and manganese are as follows. Magnesium is converted to Mg · O · 01—0.06 mol in terms of MgO, and yttrium is converted to Y · O in terms of O · 0007—0.

.03 Monole and manganese are contained in MnO as 0.00002—0.03 monole.

[0057] That is, the magnesium content relative to 1 mol of normo If it is small or more than 0.06 mol, the temperature coefficient of the dielectric constant of the dielectric ceramic becomes large. The yttrium content per mole of norium is

twenty three

[0058] Furthermore, the dielectric ceramic of the present embodiment has an average particle size force of .05-0.25 〃m of crystal particles mainly composed of barium titanate.

[0059] That is, by setting the average particle size of the crystal particles mainly composed of barium titanate to 0.05 to 0.25 μm, the barium titanate is the main component as in the first embodiment. The crystal grains to be made have a crystal structure mainly composed of a cubic system, and have a small hysteresis force in the electric field dielectric polarization characteristics and exhibit characteristics close to paraelectricity. On the other hand, when the average particle size of the crystal grains containing barium titanate as the main component is smaller than 0.05 in, the contribution of orientational polarization is lost and the dielectric constant of the dielectric ceramic decreases. On the other hand, when the average particle size of the crystal particles is larger than 0.25 m, a tetragonal crystal phase is observed in the measurement by X-ray diffraction, and the temperature coefficient of the dielectric constant of the dielectric ceramic becomes large. .

[0060] Further, in the present invention, the average particle diameter of the crystal grains is more preferably 0.15-0.2 111 in that the polarization charge at 0V can be ²⁰ nC / cm ² or less in the electric field dielectric polarization characteristics.

Yes

[0061] Further, as preferable contents of niobium, magnesium, yttrium, manganese, silicon, and boron, magnesium with respect to 1 mol of barium is in the form of Mg · O · 17 · -0.06 monole and yttrium force in terms of Ο. 0015〜0.01 Monore, Manganese power 0.0Μ01 in terms of ^ ΜηΟ

twenty three

~ 0.03 mol, and niobium is converted to NbO with respect to 100 parts by mass of barium titanate.

2 5 in the range of 6.3-15.6 parts by mass, silicon in the range of 0.73-3.13 parts by mass in terms of SiO and boron in the range of 0.31-1.04 parts by mass in terms of BO. Titanium for 1 mole of lithium

twenty three

Those having a molar ratio of 0.97-0.98 are preferred. The dielectric ceramic of this range, the definitive relative dielectric constant 25 ° C 400 or more, 380 or more relative dielectric constant at 125 ° C, the temperature coefficient of the dielectric constant in absolute value 400 X 10- ⁶ / ° C or less It becomes possible to. Next, a method for manufacturing the dielectric ceramic according to the present embodiment will be described.

First, as raw material powders, BaCO powder with a purity of 99% or more, TiO powder,

3 2

Use MgO powder, Y 2 O powder and MnCO powder. These raw material powders are

2 3 3

As in the first embodiment, MgO is 0.01 to 0.06 monole, YO is 0.00007 to 0.03 monole, and MnCO is 0.00002 to 0 per mol of barium constituting barium titanate. .03

2 3 3

Each is blended in the proportion of

[0063] Next, the mixture of the raw material powders described above is wet-mixed and dried, and then calcined at a temperature range of 900 to 11 oo ° C to obtain a calcined powder. Smash.

[0064] Next, 4 to 32 parts by mass of Nb 2 O powder, 0.7 to 6.0 parts by mass of SiO powder, and 0.3 to 2.0 parts by mass of BO with respect to 100 parts by mass of the calcined powder. Mix in proportions. Where Si

twenty three

By adding O and B 2 O in the above ranges, crystal particles mainly composed of barium titanate can be liquid phase sintered, and firing at a low temperature becomes possible. In general, during liquid phase sintering, ceramic particles have a force S, which is considered to facilitate grain growth, and the above composition can suppress grain growth during liquid phase sintering.

[0065] Then, the mixed powder is formed into a pellet and fired in the air at a temperature range of 1100 ° C to 1250 ° C to obtain the dielectric ceramic according to the present embodiment. Here, the firing temperature varies with the amount of SiO and B 2 O added, but when the firing temperature is lower than 1100 ° C, it cannot be sufficiently densified and the density of the dielectric ceramic becomes low. On the other hand, if the firing temperature is higher than 1250 ° C, the crystal grains may grow too much.

Next, the capacitor of this embodiment will be described. In the capacitor of this embodiment, the dielectric layer 13 shown in FIG. 1 exhibits temperature characteristics of a high dielectric constant and a stable relative dielectric constant, has a small spontaneous polarization, and is formed by the dielectric ceramic of this embodiment described above. /! Therefore, the capacitor of the present embodiment is a capacitor having a higher capacity and a more stable capacitance-temperature characteristic than the conventional capacitor, like the capacitor described in the first embodiment. For this reason, when this capacitor is used in a power supply circuit, it is possible to suppress the generation of noise noise due to the electrically induced distortion.

Other configurations are the same as those of the first embodiment described above, and thus description thereof is omitted. [0067] <Third Embodiment>

Next, a third embodiment of the present invention will be described. The dielectric ceramic according to the present embodiment is mainly composed of barium titanate and contains magnesium, yttrium, manganese, niobium, silicon and lithium. The content thereof is magnesium with respect to 1 mol of barium. Is converted to MgO as 0 · 01—0.06 mol, and yttrium is converted to YO as 0 · 0007—0

twenty three

.03 Monole and manganese contained in MnO equivalent 0.0.0002—0.03 Monore, and for 100 parts by mass of barium titanate, niobium in terms of NbO 4.2-33.3 parts by mass, silicon

twenty five

Is contained in an amount of 0.73-6.3 parts by mass in terms of SiO and 0.31-2.1 parts by mass of lithium in terms of Li 2 O.

[0068] Further, the dielectric ceramic according to the present embodiment includes crystal grains mainly composed of barium titanate and a grain boundary phase formed between the crystal grains, and the average grain size of the crystal grains is 0. 05 to 0.25 μm.

[0069] When the dielectric ceramic is in the above composition and particle size range, the relative dielectric constant at 25 ° C is 250 or more and the relative dielectric constant at 125 ° C, as in the first and second embodiments. Over 230 and 25 ° C ~; temperature coefficient of relative permittivity between 125 ° C ((ε-ε) / ε (125− 25))

125 25 25

The absolute value can below 1000 X 10- ⁶ / ° c, the field - dielectric polarization hysteresis in the characteristic small les, if capable of forming a dielectric ceramic Les is advantageous cormorants.

[0070] In such a dielectric ceramic according to the present embodiment, magnesium, yttrium, manganese, and niobium are dissolved in barium titanate, and silicon and lithium are included in the grain boundary phase.

[0071] In addition, magnesium, yttrium, manganese, and niobium are dissolved in barium titanate having a tetragonal crystal structure and ferroelectricity, and the average particle size of crystal grains mainly composed of barium titanate is determined. By setting the range of 0.05 to 0. 25 m, the crystal structure of the crystal grains can be mainly composed of cubic system. As a result, the ferroelectricity due to the tetragonal crystal structure is lowered, the paraelectricity can be increased, and the spontaneous polarization can be reduced by increasing the paraelectricity.

[0072] Further, by making the crystal structure of the crystal grains mainly composed of barium titanate into a crystal structure mainly composed of a cubic system, as in the first and second embodiments, the relative dielectric constant is obtained. Rate of change The curve showing is flat in the temperature range of −55 ° C. to 125 ° C. In both cases, the hysteresis in the electric field-induced polarization characteristics is reduced. Therefore, it is possible to obtain a dielectric ceramic having a low relative dielectric constant temperature coefficient despite having a relative dielectric constant of 250 or more.

[0073] That is, when a predetermined amount of magnesium, yttrium, and manganese is contained in barium titanate within the above-described range, a Curie temperature of 25 ° C or higher is exhibited, and the temperature coefficient of relative permittivity is a positive value. The dielectric ceramic having the dielectric characteristics shown in FIG. 1 is obtained. However, when the dielectric ceramic having such dielectric characteristics is further incorporated with niobium, silicon, and lithium, the effect of the present invention appears greatly, and the specific dielectric The temperature coefficient of the rate can be reduced and the temperature characteristics can be flattened. In this case, the curve indicating the rate of change of the relative permittivity has two peaks centered at 25 ° C in the temperature range of -55 ° C to 125 ° C.

[0074] In particular, according to this embodiment, liquid phase sintering can be performed by containing silicon and lithium in a specific ratio, and firing at a low temperature (1100 to 1250 ° C) becomes possible.

Here, each of the oxides of niobium, silicon, and lithium has a function of suppressing the coarsening of crystal grains mainly composed of barium titanate, and niobium is added to 100 parts by mass of barium titanate. Contains 4.2-33.3 parts by mass in terms of NbO, 0.73-6. 3 parts by mass of silicon in terms of SiO, and 0.31-2.1 parts by mass of lithium in terms of Li 2 O.

In addition, the relative dielectric constant at 125 ° C. is less than 230.

[0077] Further, the silicon content relative to 100 parts by mass of barium titanate is less than 0.73 parts by mass in terms of SiO, or the lithium content is less than 0.31 parts by mass in terms of Li 2 O. In the case of V, in the case of firing at a low temperature (1100-; 1250 ° C), the dielectric porcelain cannot be densified and the relative dielectric constant may be lowered.

[0078] On the other hand, when the silicon content relative to 100 parts by mass of barium titanate is more than 6.3 parts by mass in terms of SiO, or when lithium is more than 2.1 parts by mass in terms of Li 2 O, As the dielectric constant of dielectric ceramic decreases, the temperature coefficient of dielectric constant may increase. is there.

[0079] Further, the contents of magnesium, yttrium, and manganese are 0 · 01—0.06 mol in terms of MgO and 0 · 0007—0 in terms of Y 2 O with respect to 1 mol of normium.

twenty three

.03 Monole and manganese are contained in MnO as 0.00002—0.03 monole.

[0080] That is, when the magnesium content relative to 1 mol of normodium is less than 0 · 01 monole or more than 0.06 mol in terms of MgO, the temperature coefficient of the dielectric constant of the dielectric ceramic increases. . In addition, the yttrium content per mole of norium is 0.000 in terms of Y 2 O.

twenty three

That is, by setting the average particle size of the crystal particles mainly composed of barium titanate to 0.05 to 0.25 μm, as in the first and second embodiments, barium titanate. Thus, the crystal grains mainly composed of cubic have a crystal structure mainly composed of a cubic system, and the hysteresis in the electric field dielectric polarization characteristics is small and the characteristics close to paraelectricity can be obtained. On the other hand, when the average particle size of the crystal grains mainly composed of barium titanate is smaller than 0.05 m, the contribution of the orientation polarization is lost and the relative permittivity of the dielectric ceramic is lowered. . On the other hand, when the average particle size of the crystal particles is larger than 0.25 m, a tetragonal crystal phase is observed in the measurement by X-ray diffraction, and the temperature coefficient of the dielectric constant of the dielectric ceramic becomes large.

[0083] Further, in this embodiment, even in the electric field-dielectric polarization characteristics, the average grain size of the crystal grains is that the polarization charge at 0 V can be reduced to 20 nC / cm ² or less. The diameter is more preferably 0.15-0.2 111.

[0084] Further, as preferable niobium, magnesium, yttrium, manganese, silicon and lithium contents, magnesium per mol of barium is 0.017—0.06 monole in terms of MgO and 0.05 in terms of yttrium force. 〜0.01 Monore, Manganese power 0.0 in terms of ΜηΟ

twenty three

; ~ 0.03 mole ratio, and niobium is less than 100 parts by weight of barium titanate. 6. 0 ₅ conversion 3-15. 6 parts by weight, silicon 0.1 in Si_〇 ₂ terms 73-3. 13 parts by mass of Lithium is 0. In Li O terms 31-1. In the range of 04 parts by weight In addition, the molar ratio of titanium to 1 mole of barium is 0.997-0.98. The dielectric ceramic of this range, the relative dielectric constant at 25 ° C 400 or more, 380 or more relative dielectric constant at 125 ° C, the temperature coefficient of the dielectric constant with an absolute value below 400 X 10- ⁶ / ° C It becomes possible to do.

Use MgO powder, Y 2 O powder and MnCO powder. These raw material powders are

As in the first embodiment, MgO is 0.01 to 0.06 monole, YO is 0.00007 to 0.03 monole, and MnCO is 0.00002 to 0 per mol of barium constituting barium titanate. Mix in the proportion of 03 moles.

[0086] Next, the mixture of the raw material powders described above is wet-mixed and dried, and then calcined in the temperature range of 900 to 1100 ° C to obtain a calcined powder. Smash.

[0087] Next, 4 to 32 parts by mass of Nb 2 O powder, 0.7 to 6.0 parts by mass of SiO powder, and 0.3 to 2.0 parts by mass of Li 2 O powder with respect to 100 parts by mass of the calcined powder. Mix in parts. Here, by adding SiO and Li 2 O in the above range, crystal particles mainly composed of barium titanate can be liquid phase sintered, and firing at a low temperature becomes possible. In general, during liquid phase sintering, ceramic particles have a force S, which is considered to facilitate grain growth, and the above composition can suppress grain growth during liquid phase sintering.

[0088] The dielectric ceramic of this embodiment can be obtained by forming the mixed powder into a pellet and firing it in the air at a temperature range of 1100 ° C to 1250 ° C. Here, the firing temperature changes with the amount of SiO or Li 2 O added. When the firing temperature is lower than 1100 ° C, it cannot be sufficiently densified and the density of the dielectric ceramic becomes low. On the other hand, if the firing temperature is higher than 1250 ° C, crystal grains may grow too much.

Yes

[0089] Next, the capacitor of this embodiment will be described. In the capacitor of this embodiment, the dielectric layer 13 shown in FIG. 1 exhibits temperature characteristics of a high dielectric constant and a stable relative dielectric constant, has a small spontaneous polarization, and is formed by the dielectric ceramic of this embodiment described above. /! Gatsutsu Thus, like the capacitors described in the first and second embodiments, the capacitor according to the present embodiment is a capacitor having a higher capacity and a more stable capacitance-temperature characteristic than the conventional capacitor. For this reason, when this capacitor is used in a power supply circuit, it is possible to suppress the generation of noise caused by electrical induced distortion.

Other configurations are the same as those in the first and second embodiments described above, and thus the description thereof is omitted.

[0090] Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.

[0091] [Example I]

The evaluation sample was produced as follows. First of all, BaC with 99.9% purity

O powder, TiO powder, MgO powder, Y 2 O powder, and MnCO powder were prepared and mixed at the ratio shown in Table 1 to prepare a mixed powder. The amounts of magnesium (Mg), yttrium (Y) and manganese (Mn) shown in Table 1 are the amounts corresponding to MgO, Y 2 O and MnO, respectively. Titanium (Ti) is a molar ratio with respect to 1 mole of barium (Ba).

Next, the mixed powder prepared above was calcined at a temperature of 1000 ° C. to prepare a calcined powder, and then the calcined powder obtained was pulverized to have the average particle size shown in Table 1. A calcined powder was obtained. The average particle size of the calcined powder is determined by dispersing the obtained calcined powder on a sample stage for an electron microscope, observing it with a scanning electron microscope, taking a picture, and taking the photograph of the calcined powder reflected in the photograph. The contour was image-processed, each powder was regarded as a circle, its diameter was determined and averaged. The magnification of the photo was 30000 times, the number of observation points was 3 for each sample, and the average value was obtained. Thereafter, Nb 2 O powder having a purity of 99.9% was mixed at a ratio shown in Table 1 with respect to 100 parts by mass of the calcined powder. This mixed powder was granulated and formed into pellets having a diameter of 16.5 mm and a thickness of 1 mm.

Next, 10 pellets of each composition were fired at a temperature shown in Table 1 in the air. The average particle size of crystal particles mainly composed of barium titanate was determined as follows. First, the fracture surface of the fired sample is roughly polished with # 1200 abrasive paper, then polished with a 3 m diameter diamond paste applied on a hard buff, and then soft buffed. Alumina abrasive grains having a particle size of 0.3 m were applied on the surface, and finish polishing was performed. Next, after etching with an acidic aqueous solution (hydrochloric acid hydrogen fluoride), a photograph of the internal tissue was taken using a scanning electron microscope. Next, the contours of the crystal grains shown in the photograph were image-processed, each particle was regarded as a circle, the diameter was obtained, and the average was obtained. The magnification of the photograph was about 30000 times, the number of observation points was 3 for each sample, and the average value was obtained.

[0094] An indium gallium conductor layer was printed on the surface of the fired sample to obtain a dielectric property evaluation sample (Sample Nos. I— ;! to 34 in Tables 2 and 3).

[0095] <Evaluation>

These samples, which are dielectric ceramics, were measured for capacitance using an LCR meter 4284A (HP) at a frequency of 1. OkHz, an input signal level of 1.0 V, and temperatures of 25 ° C and 125 ° C. The specific dielectric constants at 25 ° C and 125 ° C were calculated from the diameter and thickness of the sample and the area of the conductor layer. The temperature coefficient of the relative permittivity was calculated by applying the relative permittivity at 25 ° C and 125 ° C to the formula (1). For these measurements, the number of samples was 10 and the average value was obtained.

[0096] Further, for the obtained sample, the magnitude of the electrically induced strain was obtained by measuring dielectric polarization (polarization charge). In this case, the evaluation was made based on the amount of charge (residual polarization) at 0 V when the voltage was changed in the range of ± 1250 V.

[0097] The composition analysis of the sample was performed by ICP (Inductively Coupled Plasma) analysis or atomic absorption analysis. In this case, the obtained sample was mixed with boric acid and sodium carbonate, and the molten material was dissolved in hydrochloric acid. First, qualitative analysis of the elements contained in the sample was performed by atomic absorption spectrometry, and then identified. The diluted standard solution for each element was used as a standard sample and quantified by ICP emission spectroscopic analysis. The amount of oxygen was determined using the valence of each element as the valence shown in the periodic table.

[0098] Table 1 shows the prepared composition, the average particle size of the calcined powder, and the firing temperature, and Tables 2 and 3 show the average particle size and characteristics of the fired crystal particles (relative permittivity and temperature coefficient of relative permittivity). Absolute values, specific dielectric constant temperature change curves, and polarization charges) are shown.

[0099] Here, the amount of Nb 2 O added in Table 1 is a ratio with respect to 100 parts by mass of the calcined powder.

. On the other hand, the NbO content in Tables 2 and 3 is the titanium content in the dielectric ceramic (sample). It is a ratio with respect to 100 parts by mass of barium acid. The amounts of Mg, Y and Mn shown in Tables 2 and 3 are oxide equivalents. In Tables 2 and 3, “average particle size of crystal particles” means the average particle size of crystal particles mainly composed of barium titanate. “Absolute value of temperature coefficient of relative permittivity” in Tables 2 and 3 means the absolute value of the average value of the temperature coefficient of relative permittivity obtained above. In Tables 2 and 3, those with no circles in the curve of the relative dielectric constant temperature change are those for which the two peaks centered at 25 ° C were not observed. If the column is marked with a circle, it indicates that the polarization charge is less than 20nC / cm ² ! /, And the sample.

[Table 1] of calcined powder

Composition Firing temperature Average particle size

Sample No.

Ba Mg Y Mn Τί Nb ₂ 0 ₅

U m ° c mol mol mol mol-parts by mass

* I- 1 1 0.02 0.01 0.01 0.98 2.0 0.1 1200

1- 2 1 0.02 0.01 0.01 0.98 4.0 0.1 1200

1- 3 1 0.02 0.01 0.01 0.98 6.0 0.1 1200

1-4 1 0.02 0.01 0.01 0.98 8.5 0.1 1200

I- 5 1 0.02 0.01 0.01 0.98 15.0 0.1 1200

1- 6 1 0.02 0.01 0.01 0.98 18.5 0.1 1200

1-7 1 0.02 0.01 0.01 0.98 32.0 0.1 1200 氺 1-8 1 0.02 0.01 0.01 0.98 50.0 0.1 1200

* 1-9 1 0.02 0.0002 0.01 0.98 8.5 0.1 1200

I― 9a 1 0.02 0.0007 0.01 0.98 8.5 0.1 1200

I- 10 1 0.02 0.0015 0.01 0.98 8.5 0.1 1200

I- 11 1 0.02 0.005 0.01 0.98 8.5 0.1 1200

I- 12 1 0.02 0.007 0.01 0.98 8.5 0.1 1200

I- 13 1 0.02 0.03 0.01 0.98 8.5 0.1 1200

* I- 14 1 0.02 0.04 0.01 0.98 8.5 0.1 1200

* I 1 15 1 0.005 0.01 0.01 0.98 8.5 0.1 1200

I- 16 1 0.01 0.01 0.01 0.98 8.5 0.1 1200

I- 17 1 0.017 0.01 0.01 0.98 8.5 0.1 1200

I- 18 1 0.023 0.01 0.01 0.98 8.5 0.1 1200

I- 19 1 0.06 0.01 0.01 0.98 8.5 0.1 1200

* 1-20 1 0.07 0.01 0.01 0.98 8.5 0.1 1200

1-21 \ 0.02 0.01 0.0002 0.98 8.5 0.1 1200

1 0.02 0.01 0.005 0.98 8.5 0.1 1200

I-23 1 0.02 0.01 0.008 0.98 8.5 0.1 1200

1-24 1 0.02 0.01 0.015 0.98 8.5 0.1 1200

1- 25 1 0.02 0.01 0.03 0.98 8.5 0.1 1200

* 1- 26 1 0.02 0.01 0.04 0.98 8.5 0.1 1200

1- 27 1 0.02 0.01 0.01 0.97 8.5 0.1 1200

1-28 1 0.02 0.01 0.01 0.99 8.5 0.1 1200

* 卜 29 1 0.02 0.01 0 0.98 8.5 0.1 1200

1-30 1 0.02 0.03 0.01 0.98 8.5 0.04 1200

* 1-31 1 0.02 0.03 0.01 0.98 8.5 0.04 1100

1-32 1 0.02 0.01 0.01 0.98 4.0 0.1 1280

1-33 1 0.02 0.01 0.01 0.98 8.5 0.1 1150

1 0.02 0.01 0.01 0.98 8.5 0.1 1250

* Indicates a sample that is outside the range of this image.

Indication of

suoll

As is apparent from the results in Tables 2 and 3, Sample No. I which is the dielectric ceramic of the present invention.

― 2 7 9a 10-13, 16-19, 21-25, 27 28 30 33 and 34 Definitive relative dielectric constant of 250 or more, 230 or more relative dielectric constant at 125 ° C, the temperature coefficient of the dielectric constant at 25-125 ° C is was 1000 X 10- ⁶ / ° C or less in absolute value.

[0104] Special metal, Norium 1 monolayer, MgO 0.01 to 0.06 monolayer, YO 0.005 to 0.00.

01 monole, MnO 0 · 01—0.03 monole, the main component of barium titanate is 100 parts by mass of Nb 2 O. The content of NbO is 6.3-15. 6 parts by mass, and titanium per mol of norm Sample Nos. I—3 to 5, 11, 12, 17 to; 19, 24, 25, 27

In 33 and 34, more than 400 relative dielectric constant at 25 ° C, the relative dielectric constant force ¾80 or more at 125 ° C, the temperature coefficient of the relative dielectric constant of 400 X 10- ⁶ / ° C or less in absolute value, The curve showing the rate of change of the relative dielectric constant had two peaks in the temperature range of -55 ° C to 125 ° C, and no large hysteresis was observed in the measurement of the electric field dielectric polarization characteristics. In the samples where no hysteresis was observed, the sample had a polarization charge at 0V! /, 20 nC / cm ² or less.

[0105] Fig. 2 shows the X-ray diffraction pattern of the dielectric ceramic of sample No. I-4 arbitrarily selected from these samples, and Fig. 3 shows the graph showing the change in relative permittivity of the sample. Figure 4 shows the electric field dielectric polarization characteristics. In FIG. 3, Sample Nos. 1 33 and 34, which are samples outside the scope of the present invention, are shown for comparison.

[0106] As shown in Figs. 2 to 4, the dielectric ceramic of Sample No. I-4 has a crystal structure mainly composed of a cubic system, and the temperature characteristics of relative permittivity is 25. It had two peaks centered around ° C, the rate of change of relative permittivity was small, and the hysteresis of electric field dielectric polarization characteristics was small. In addition, the other samples had a crystal structure mainly composed of a cubic system, and the rate of change in relative permittivity was small.

[0107] On the other hand, samples outside the scope of the present invention (Sample Nos. I-1, 8, 9, 14, 15, 20, 26, 2

9, the 31 and 32), there is a hysteresis in the dielectric constant is less than 200 forces ,, or dielectric partial pole in 25 ° C, in absolute value temperature coefficient of the dielectric constant 1000 X 10- ⁶ / ° C It was bigger than that.

[0108] [Example Π]

The evaluation sample was produced as follows. First, prepare BaCO powder, TiO powder, MgO powder, YO powder, and MnCO powder with a purity of 99.9%, and the proportions shown in Table 4 And mixed powder was prepared.

[0109] Next, after the mixed powder prepared above was calcined at a temperature of 1000 ° C to prepare a calcined powder, the calcined powder obtained was pulverized to have an average particle size shown in Table 4 A calcined powder was obtained. The average particle size of the calcined powder was determined in the same manner as in Example I. Thereafter, Nb 2 O powder, SiO powder and B 2 O powder with a purity of 99.9% were mixed in a proportion shown in Table 4 with respect to 100 parts by mass of the calcined powder. This mixed powder was granulated and formed into a pellet shape having a diameter of 16.5 mm and a thickness of 1 mm.

Next, 10 pellets of each composition were fired at a temperature shown in Table 4 in the air. An indium gallium conductor layer was printed on the surface of the fired sample to obtain a dielectric property evaluation sample (Sample Nos. II— in Tables 5 and 6;! -45). The average particle size of the crystal particles mainly composed of barium titanate was determined in the same manner as in Example I.

[0111] <Evaluation>

For these samples, which were dielectric ceramics, the dielectric constant, the temperature coefficient of the dielectric constant, and the polarization charge were determined in the same manner as in Example I. Further, the composition analysis of the sample was performed in the same manner as in Example I. Further, the oxygen amount was determined in the same manner as in Example I.

Yes

[0112] Table 4 shows the preparation composition, the average particle size and calcining temperature of the calcined powder, and Table 5 and Table 6 show the results of the average particle size and characteristics of the crystal particles after firing, respectively.

Here, “average particle size of crystal particles” in Tables 5 and 6 means the average particle size of crystal particles mainly composed of barium titanate. “Absolute value of temperature coefficient of relative permittivity” in Tables 5 and 6 means the absolute value of the average value of the temperature coefficient of relative permittivity. In Tables 5 and 6, those with no circles in the curve of the relative permittivity temperature change curve are those for which the two peaks centered at 25 ° C were not observed. The ones not marked with ◯ in the column indicate that the polarization charge is not less than ²⁰ nC / cm ² ! /, Respectively.

[0114] [Table 4] composition

Calcined powder

Amount for Bal mol Amount for calcined powder Amount for 100 parts by mass

MgO Y ₂ 0 ₃ MnC0 ₃ Ti Nb ₂ 0 ₅ Si0 ₂ B ₂ 0 ₃

Mol mol mol mol part m ° c

* II- 1 0.020 0.010 0.010 0.980 2 1.5 0.5 0.1 1200

* II -2 0.020 0.010 0.010 0.980 3.5 1.5 0.5 0.1 1200

【卜 3 0.020 0.010 0.010 0.980 4 1.5 0.5 0.1 1200

[1-4 0.020 0.010 0.010 0.980 6 1.5 0.5 0.1 1200

II -5 0.020 0,010 0.010 0.980 8.5 1.5 0.5 0.1 1200

II- 6 0.020 0.010 0.010 0.980 15 1.5 0.5 0.1 1200

II-7 0.020 0.010 0.010 0.980 18.5 1.5 0.5 0.1 1200

II -8 0.020 0.010 0.010 0.980 32 1.5 0.5 0.1 1200

* II -9 0.020 0.010 0.010 0.980 50 1.5 0.5 0.1 1200

* II- 10 0.020 0.0002 0.010 0.980 8.5 1.5 0.5 0.1 1200

11-11 0.020 0.0007 0.010 0.980 8.5 1.5 0.5 0.1 1200

II- 12 0.020 0.0015 0.010 0.980 8.5 1.5 0.5 0.1 1200

【卜 13 0.020 0.005 0.010 0.980 8.5 1.5 0.5 0.1 1200

14-14 0.020 0.007 0.010 0.980 8.5 1.5 0.5 0.1 1200

IE-15 0.020 0.030 0.010 0.980 8.5 1.5 0.5 0.1 1200

* II- 16 0.020 0.040 0.010 0.980 8.5 1.5 0.5 0.1 1200

* II- 17 0.005 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

Εϊ-18 0.010 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

11-19 0.017 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

II -20 0.023 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

11-21 0.040 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

II-22 0.060 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

* II -23 0.070 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

II -24 0.020 0.010 0.0002 0.980 8.5 1.5 0.5 0.1 1200

11-25 0.020 0.010 0.005 0.980 8.5 1.5 0.5 0.1 1200

11-26 0.020 0.010 0.008 0.980 8.5 1.5 0.5 0.1 1200

II -27 0.020 0.010 0.013 0.980 8.5 1.5 0.5 0.1 1200

II -28 0.020 0.010 0.015 0.980 8.5 1.5 0.5 Ο.ΐ 1200

[[-29 0.020 0.010 0.030 0.980 8.5 1.5 0.5 0.1 1200

* ίϊ-30 0.020 0.010 0.040 0.980 8.5 1.5 0.5 0.1 1200

II- 31 0.020 0.010 0.010 0.970 8.5 1.5 0.5 0.1 1200

II -32 0.020 0.010 0.010 0.990 8.5 1.5 0.5 0.1 1200

* II -33 0.020 0.010 0 0.980 8.5 1.5 0.5 0.1 1200

* U-34 0.020 0.010 0.010 0.980 8.5 0.375 0.125 0.1 1300

11-35 0.020 0.010 0.010 0.980 8.5 0.7 0.3 0.1 1250

II -36 0.020 0.010 0.010 0.980 8.5 2.5 0.5 0.1 1170

11-37 0.020 0.010 0.010 0.980 8.5 3 1 0.1 1150

11-38 0.020 0.010 0.010 0.980 8.5 4.5 1.5 0.1 1150

II- 39 0.020 0.010 0.010 0.980 8.5 6 2 0.1 1100

* Π-40 0.020 0.010 0.010 0.980 8.5 7 2.2 0.1 1100

11-41 0.020 0.030 0.010 0.980 8.5 1.5 0.5 0.04 1200

* II -42 0.020 0.030 0.010 0.980 8.5 1.5 0.5 0.04 1160

* II -43 0.020 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1230

* 【〖-44 0.020 0.010 0.010 0.980 8.5 6 0.125 0.1 1170

* 11-45 0.020 0.010 0.010 0.980 8.5 0.5 2 0.1 1170

The * mark is one of * outside the scope of the invention. Five]

* Indicates the scope of the invention.

* Indicates the scope of the invention

S] (Saint 6I 1 [0117] As is apparent from the results in Tables 5 and 6, Sample Nos. II-3-8, 11-15, 18-22, 24-29, 31, 32, 35, which are dielectric ceramics of the present invention. ~ 39 and 41, 25. Contact Keru dielectric constant of 250 or more and C, and a dielectric constant of 230 or more at 125 ° C, 25 temperature coefficient of the dielectric constant at ~ 125 ° C is 1000 X 10- ⁶ / ° C or less in absolute value there were.

[0118] SPECIAL, NORIUM 1 MONOLE, MgO 0.01 ~ 0.06 MONO, YO 0.0015 ~ 0

• 01 monole, MnO 0 · 01—0.03 monole, the main component is 30 wt. W of NbO with 6.3-15.6 parts by mass, and SiO is 0.73-. 3. 13 parts by mass and BO are 0 · 31—1.04 parts by mass, and the molar ratio of titanium to 1 mol of norm is 0 · 97.

Sample No. II of ˜0.98—4 to 6, 12 to; 14, 19 to 22, 27 to 29, 31 and 35 to 37, the relative dielectric constant at 25 ° C. is 400 or more, at 125 ° C. relative dielectric constant of 380 or more, the ratio temperature coefficient of the dielectric constant of 400 X 10- ⁶ / ° C or less in absolute value, the rate of change in dielectric constant indicates to curve - 55 ° to 125 temperature ° C There were two peaks in the range, and no significant hysteresis was observed in the measurement of dielectric polarization! ! /, Such seen hysteresis samples, polarization charge you to 0V! /, Was 20nC / cm ² or less Te.

[0119] Figure 5 shows the X-ray diffraction pattern of the dielectric ceramic of Sample No. II-4 arbitrarily selected from these samples. As shown in Fig. 5, the dielectric ceramic of Sample No. II-4 was mainly composed of cubic crystal.

[0120] Also, other samples within the scope of the present invention have a crystal structure mainly composed of a cubic system.

[0121] On the other hand, samples outside the scope of the present invention (Sample Nos. 11-1, 1, 2, 9, 10, 16, 17, 23, 30, 33, 34, 40, 42 to 45) twenty five. The force ,, or less than匕誘conductivity force 250 at C of hysteresis to dielectric polarization, the temperature coefficient of the relative dielectric constant was in absolute value 1009 X 10- ⁶ / ° C or more. Sample No. II-34 has not been evaluated due to insufficient sintering.

[0122] [Example ΙΠ]

The evaluation sample was produced as follows. First, BaC O powder, TiO powder, MgO powder, YO powder, and MnCO powder each having a purity of 99.9% were prepared and mixed at the ratios shown in Table 7 to prepare a mixed powder. [0123] Next, after the mixed powder prepared above was calcined at a temperature of 1000 ° C to prepare a calcined powder, the obtained calcined powder was pulverized to have an average particle size shown in Table 7 A calcined powder was obtained. The average particle size of the calcined powder was determined in the same manner as in Example I. Thereafter, Nb 2 O powder, SiO powder and Li 2 O powder with a purity of 99.9% were mixed in a proportion shown in Table 7 with respect to 100 parts by mass of the calcined powder. This mixed powder was granulated and formed into a pellet shape having a diameter of 16.5 mm and a thickness of 1 mm.

Next, 10 pellets of each composition were fired at a temperature shown in Table 7 in the air. An indium gallium conductor layer was printed on the surface of the sample after firing to obtain a sample for evaluation of dielectric properties (Sample Nos. Ill— ;! to 45 in Table 8 and Table 9). The average particle size of the crystal particles mainly composed of barium titanate was determined in the same manner as in Example I.

[0125] <Evaluation>

Yes

[0126] Table 7 shows the preparation composition, the average particle size of the calcined powder, and the firing temperature, and Tables 8 and 9 show the results of the average particle size and characteristics of the crystal particles after firing.

[0127] Here, the "average particle diameter of crystal grains" in Tables 8 and 9 means the average particle diameter of crystal grains mainly composed of barium titanate. “Absolute value of temperature coefficient of relative permittivity” in Tables 8 and 9 means the absolute value of the average value of the temperature coefficient of relative permittivity. In Tables 8 and 9, those with no circle in the curve of the relative permittivity temperature change curve are those for which the two peaks centered at 25 ° C were not observed. The ones not marked with ◯ in the column indicate that the polarization charge is not less than ²⁰ nC / cm ² ! /, Respectively.

[0128] [Table 7] composition

Amount relative to 1 mol of Ba calcined powder Amount relative to the top of 100 quality Sample of calcined powder No. Average particle size Firing temperature

MgO Y ₂ 0 ₃ MnC0 ₃ Ti Nb ₂ 0 ₅ Si0 ₂ Li ₂ 0

Mol mol mol mol mass part mass part g tatami part a m ° c

* III-1 0.020 0.010 0.010 0.980 2 1.5 0.5 0.1 1200

* III-2 0.020 0.010 0.010 0.980 3.5 1.5 0.5 0.1 1200

III-3 0.020 0.010 0.010 0.980 4 1.5 0.5 0.1 1200

III-4 0.020 0.010 0.010 0.980 6 1.5 0.5 0.1 1200

III-5 0.020 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-6 0.020 0.010 0.010 0.980 15 1.5 0.5 0.1 1200

III-7 0.020 0.010 0.010 0.980 18.5 1.5 0.5 0.1 1200

III-8 0.020 0.010 0.010 0.980 32 1.5 0.5 0.1 1200

* III-9 0.020 0.010 0.010 0.980 50 1.5 0.5 0.1 1200

* III-10 0.020 0.0002 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-1 1 0.020 0.0007 0.010 0.980 8.5 1.5 0.5 0.1 1200

HI-12 0.020 0.0015 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-13 0.020 0.005 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-14 0.020 0.007 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-15 0.020 0.030 0.010 0.980 8.5 1.5 0.5 0.1 1200

* III-16 0.020 0.040 0.010 0.980 8.5 1.5 0.5 0.1 1200

* HI-17 0.005 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-18 0.010 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-19 0.017 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-20 0.023 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-21 0.040 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

III-22 0.060 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

* III-23 0.070 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1200

0.020 0.010 0.0002 0.980 8.5 1.5 0.5 0.1 1200

III-25 0.020 0.010 0.005 0.980 8.5 1.5 0.5 0.1 1200

III 1 26 0.020 0.010 0.008 0.980 8.5 1.5 0.5 0.1 1200

III-27 0.020 0.010 0.013 0.980 8.5 1.5 0.5 0.1 1200

III-28 0.020 0.010 0.015 0.980 8.5 1.5 0.5 0.1 1200

III-29 0.020 0.010 0.030 0.980 8.5 1.5 0.5 0.1 1200

* III-30 0.020 0.010 0.040 0.980 8.5 1.5 0.5 0.1 1200

III-31 0.020 0.010 0.010 0.970 8.5 1.5 0.5 0.1 1200

III-32 0.020 0.010 0.010 0.990 8.5 1.5 0.5 0.1 1200

* III-33 0.020 0.010 0 0.980 8.5 1.5 0.5 0.1 1200

* III-34 0.020 0.010 0.010 0.980 8.5 0.375 0.125 0.1 1300

III-35 0.020 0.010 0.010 0.980 8.5 0.7 0.3 0.1 1250

III-36 0.020 0.010 0.010 0.980 8.5 2.5 0.5 0.1 1 170

III-37 0.020 0.010 0.010 0.980 8.5 3 1 0.1 1 150

HI-38 0.020 0.010 0.010 0.980 8.5 4.5 1.5 0.1 1150

III-39 0.020 0.010 0.010 0.980 8.5 6 2 0.1 1 100

* III-40 0.020 0.010 0.010 0.980 8.5 7 2.2 0.1 1100

III-41 0.020 0.030 0.010 0.980 8.5 1.5 0.5 0.04 1200

* III-42 0.020 0.030 0.010 0.980 8.5 1.5 0.5 0.04 1 160

* III-43 0.020 0.010 0.010 0.980 8.5 1.5 0.5 0.1 1230

* III-44 0.020 0.010 0.010 0.980 8.5 6 0.125 0.1 1 170

* III-45 0.020 0.010 0.010 0.980 8.5 0.5 2 0.1 1170

* Indicates a test t outside the scope of the present invention.

8] [S031

As is apparent from the results in Table 8 and Table 9, sample No. Ill, which is the dielectric ceramic of the present invention. -25 for 3-8, 11-15, 18- 22, 24-29, 31, 32, 35-39 and 41. Contact Keru dielectric constant of 250 or more and C, and a dielectric constant of 230 or more at 125 ° C, 25 temperature coefficient of the dielectric constant at ~ 125 ° C is 1000 X 10- ⁶ / ° C or less in absolute value there were.

[0132] SPECIAL, NORIUM 1 MONOLE, MgO 0.01 ~ 0.06 MONO, YO 0.0015 ~ 0

• 01 monole, MnO 0 · 01—0.03 monole, the main component is 30 wt. W of NbO with 6.3-15.6 parts by mass, and SiO is 0.73-. 3. Sample No. Ill—4-6, 12 with 13 parts by mass and Li O of 0 · 31—1.04 parts by mass, and the molar ratio of titanium to 1 mol of norm is 0 · 97 to 0.98. ~; For 14, 19-22, 27-29, 31 and 35-37, the relative permittivity at 25 ° C is 400 or more, the relative permittivity at 125 ° C is 380 or more, and the relative permittivity temperature coefficient is absolute in no more than 400 X 10- ⁶ / ° C, relative dielectric constant change rate indicates to curve - has two peaks in a temperature range of 55 ° C~125 ° C, and contact to the measurement of dielectric polarization ! / No big hysteresis was seen. No hysteresis was observed! /, And the sample had a polarization charge at 0 V! /, Which was less than ²⁰ nC / cm ² .

[0133] X-ray diffraction pattern of dielectric porcelain of sample No. Ill-4 arbitrarily selected from these samples

Shown in 6. As shown in Fig. 6, the dielectric porcelain of Sample No. Ill-4 has a crystal structure mainly composed of a cubic system.

[0134] In addition, other samples within the scope of the present invention also have a crystal structure mainly composed of a cubic system.

[0135] In contrast, samples outside the scope of the present invention (Sample Nos. ΠΙ—1, 2, 9, 10, 16, 17, 23,

30, 33, 34, 40, 42-45), 25. A is the force ,, or匕誘conductivity force less than 200 in the C of hysteresis to dielectric polarization, the temperature coefficient of the relative dielectric constant was in absolute value 1043 X 10- ⁶ / ° C or more. Sample No. Ill-34 has not been evaluated due to insufficient sintering.

Claims

The scope of the claims

[1] A dielectric ceramic comprising crystal grains mainly composed of barium titanate and grain boundary phases and forces formed between the crystal grains,

Magnesium in the form of MgO in the range of 0 · 0 to 0 · 06 monole, and yttrium in the form of Y 2 O in the range of 0 · 0007 to 0 · 03

Containing 0.00002-0.03 monole in terms of ΟηΟ,

Furthermore, for 100 parts by weight of the barium titanate, niobium in terms of NbO is 4.2-3.

Containing 3 parts by weight,

And an average particle size of the crystal particles is 0.05 to 0.25 m.

[2] With respect to 1 mol of barium constituting the barium titanate, the magnesium is converted into Mg ··································· 06 Contains 0.01-0.03 moles of manganese in terms of ΜηΟ,

Containing 6.3-15.6 parts by mass of the niobium in terms of NbO with respect to 100 parts by mass of the barium titanate,

2. The dielectric ceramic according to claim 1, wherein a molar ratio of titanium to 1 mol of barium constituting the barium titanate is from 0 · 97 to 0.98.

[3] The method according to claim 1, further comprising 0.73-6.3 parts by mass of silicon in terms of SiO and 0.31-2.1 parts by mass of boron in terms of BO with respect to 100 parts by mass of barium titanate. The dielectric ceramic described.

[4] With respect to 1 mol of barium constituting the barium titanate, the magnesium is converted into Mg ······························· 06 In 0.01 to 0.03 mol in terms of ΜηΟ,

For 100 parts by mass of the barium titanate, the niobium is 6.3-15. The dielectric ceramic according to claim 1, wherein the dielectric ceramic is .about.0.98.

[5] In addition to 100 parts by mass of barium titanate, silicon is further contained in an amount of 0.773-6.3 parts by mass in terms of Si ₂ and lithium is 0.3 in terms of Li 2 O; The dielectric ceramic according to claim 1.

[6] With respect to 1 mol of barium constituting the barium titanate, the magnesium is converted into Mg ····························· 06 In 0.01 to 0.03 mol in terms of ΜηΟ,

Furthermore, with respect to 100 parts by mass of the barium titanate, 0.73-3.13 parts by mass of silicon in terms of SiO and 0.31-1.04 parts by mass of lithium in terms of Li 2 O are contained,

[7] A capacitor composed of a laminate of a dielectric layer and a conductor layer,

The dielectric ceramic constituting the dielectric layer is a dielectric ceramic composed of crystal grains mainly composed of barium titanate and a grain boundary phase formed between the crystal grains,

Containing 0.00002-0.03 monole in terms of ΟηΟ,

Containing 3 parts by weight,

The capacitor is characterized in that the average grain size of the crystal grains is 0.05-0.25 m.

[8] With respect to 1 mol of barium constituting the barium titanate, the magnesium is converted into Mg ···································· 06 Contains 0.01-0.03 moles of manganese in terms of ΜηΟ,

Containing 6.3-15.6 parts by mass of the niobium in terms of Nb 2 O relative to 100 parts by mass of the barium titanate The capacitor according to claim 7, wherein a molar ratio of titanium to 1 mol of barium constituting the barium titanate is 0 · 97 to 0 · 98.

[9] The method according to claim 7, further comprising: 0.73-6.3 parts by mass of silicon in terms of SiO and 0.31-2.1 parts by mass of boron in terms of BO with respect to 100 parts by mass of barium titanate. Listed

[10] With respect to 1 mol of barium constituting the barium titanate, the magnesium is converted into Mg ······························ 06 In 0.01 to 0.03 mol in terms of ΜηΟ,

Furthermore, with respect to 100 parts by mass of the barium titanate, 0.73-3.13 parts by mass of silicon in terms of SiO and 0.31 to 1.04 parts by mass of boron in terms of B 2 O were obtained,

8. The capacitor according to claim 7, wherein a molar ratio of titanium to 1 mol of barium constituting the barium titanate is 0 · 97 to 0.98.

[11] Claims further containing 0.773-6.3 parts by mass of SiO in terms of SiO and 0.3;! -2.1 parts by mass of Li in terms of LiO with respect to 100 parts by mass of the barium titanate. The capacitor according to Item 7.

[12] With respect to 1 mole of barium constituting the barium titanate, the magnesium is converted into Mg ································ 06 In 0.01 to 0.03 mol in terms of ΜηΟ,