JPH10273360A - Dielectric ceramic composition, production of raw material power for the dielectric ceramic composition, and production of dielectric ceramic composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate problems, such as, that the cost for producing the dielectric ceramic composition is high, because the raw material powder for the dielectric ceramic composition containing Ta2 O5 as a main component have been produced by a solid synthetic method and further because the conditions for the calcinatory synthesis of the raw material powder require a high temperature and a long time, that the cost for producing the dielectric ceramic composition is high, because the conditions comprising a high temperature and a long time must be selected, also on the production of the dielectric ceramic composition, and that the dielectric characteristics (specific dielectric constants, dielectric loss) are not so excellent, because the gain sizes of the obtained dielectric ceramic composition are large. SOLUTION: This dielectric ceramic composition is produced by preparing a solution containing a Ta compound and a Ti compound and/or a Nb compound so as to form a composition of the formula: (Ta2 O5 )1-(x+y) (TiO2 )x (Nb2 )O5 )y 0.05<=[(x)+(y)]<=0.20}, adding an alkali solution to the mixture, reacting the mixture at 100-200 deg.C in an autoclave, sintering the obtained raw material particles for the dielectric composition at a low temperature (1,320-1,380 deg.C for a short time (2-4 hr). The produced dielectric ceramic composition has a grain size of <=5 μm and is excellent in dielectric characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dielectric porcelain composition,
The present invention relates to a method for producing a raw material powder of the dielectric porcelain composition, and a method for producing a dielectric porcelain composition. More specifically, a dielectric porcelain composition used for a capacitor or the like, and a method for producing the dielectric porcelain composition And a method for producing a dielectric porcelain composition using the raw material powder.

[0002]

2. Description of the Related Art As electronic components have become lighter, thinner, smaller, and more sophisticated, electronic ceramic components mounted on these electronic components have become lighter, thinner, smaller, and more sophisticated. Is being required. Capacitors, which are one of the electronic ceramic components, have various required characteristics because they are used for various applications.For example, dielectric ceramic compositions used for multilayer capacitors have high dielectric constants and low dielectric constants. It is required to reduce the dielectric loss, lower the firing temperature, and reduce the grain size of the dielectric ceramic composition.

As a method for synthesizing the raw material powder for producing the above-mentioned dielectric ceramic composition, a solid phase synthesis method, a liquid phase synthesis method, a hydrothermal synthesis method and the like can be mentioned. As the liquid phase synthesis method, an alkoxide method, a coprecipitation method and the like are known. The alkoxide method is to prepare a uniform solution in which an alkoxide solution is mixed with each element constituting the target porcelain composition, and hydrolyze by adding water or the like to the solution to form a hydroxide having a predetermined composition. And producing a raw material powder of the porcelain composition by subjecting the hydroxide or the like to a heat treatment or the like. The coprecipitation method is to prepare a solution of these compounds using a salt or the like of each element constituting the target porcelain composition, and obtain a coprecipitate of a predetermined composition by changing the pH or the like of the solution. This is a method of producing a raw material powder of the porcelain composition by subjecting the coprecipitate to a heat treatment.

[0004] The above-mentioned liquid phase synthesizing method produces raw material powder of a predetermined composition from a liquid phase having a uniform composition, and therefore has the advantage that the composition of the raw material powder is highly uniform and fine particles can be produced. Have. However, when the porcelain composition is manufactured by firing the compact of the raw material powder, abnormal grain growth is likely to occur, and the grains constituting the porcelain composition are likely to be coarse. In addition, there is a problem that a raw material powder containing carbon may be generated at the stage of manufacturing the raw material powder.

[0005] On the other hand, the solid phase synthesis method is the most common method. After mixing powders such as oxides and carbonates of each element constituting the target porcelain composition, heat treatment (calcination) is performed at a high temperature. (Synthesis) to cause a solid-phase reaction to produce a raw material powder having the composition of the porcelain composition.
This solid-phase synthesis method has an advantage that the raw material powder of the porcelain composition can be manufactured at a relatively low cost with a relatively simple operation.

[0006]

However, in the prior art, since the particle size of the oxide or carbonate powder that can be obtained is large, the heating temperature for calcining synthesis is increased, and The heating time had to be prolonged. Therefore, the particle size of the obtained raw material powder increases, and when a porcelain composition is manufactured using the raw material powder, the grain size of the manufactured porcelain composition increases.

For example, Japanese Patent Application Laid-Open No. 9-2869 discloses a Ta ₂ O ₅ dielectric material containing TiO ₂ manufactured by a solid phase method. The publication discloses the TiO
A raw material powder of a Ta ₂ O ₅ dielectric material containing ₂ is produced by a solid-phase synthesis method.
Heating at a temperature of 350-1400 ° C. for several nights is described. Due to the high temperature and the long-time heating in the calcining synthesis step, the produced raw material powder has large particles, and therefore the firing condition of the dielectric material (porcelain composition) is also 1400 ° C. for 16 to 24 hours. And heating at high temperature for a long time. In addition, the grain size of the manufactured dielectric material is increased, and the dielectric properties (relative permittivity and dielectric loss) are not so excellent.

[0008] Materials Research Bulletin, Vo
L.31, No.3, the _{pp.295-299 (1996), (Nb 1} -x Ta x
Although a dielectric porcelain having a composition of ₂ O ₅ is disclosed, also in this case, calcination synthesis is performed at 1350 to 1400 ° C. for several nights, and the conditions for manufacturing the porcelain composition are also 1
At 450 ° C. for 10 hours, the temperature is high and extends for a long time.
Further, the dielectric properties (relative permittivity and dielectric loss) of the manufactured dielectric porcelain are not so excellent.

As described above, in the prior art, a dielectric porcelain composition containing Ta ₂ O ₅ as a main component has been produced mainly by using raw material powder produced by a solid phase synthesis method. As the conditions (1), extremely strict conditions such as a calcination temperature of 1350 ° C. or more and a calcination time of several nights (several days) had to be selected, and therefore, there was a problem that the production cost of the raw material powder was high.

Also, when producing a dielectric porcelain composition, strict conditions such as a sintering temperature of 1400 ° C. or more and a sintering time of 10 hours or more must be selected, and the production cost of the dielectric porcelain composition is high. In addition to sticking, there was a problem that it was against the demand for lowering the firing temperature.

Further, since the obtained dielectric ceramic composition has a large grain size, it is difficult to make a multilayer capacitor multilayer, and the dielectric properties (relative permittivity and dielectric loss) of the dielectric ceramic composition are not so excellent. There was a problem that.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a dielectric ceramic composition raw material capable of efficiently performing calcination synthesis at a relatively low temperature in a short time even when a solid phase synthesis method is used. Method for producing powder, method for producing dielectric porcelain composition which can be efficiently produced in a short time at relatively low temperature using dielectric porcelain composition raw material powder obtained by the method for producing said raw material powder, and method for producing said dielectric An object of the present invention is to provide a dielectric ceramic composition having a small grain size obtained by a method for producing a ceramic composition and having excellent electrical characteristics (relative permittivity, dielectric loss, and the like).

Further, the present invention provides a method for producing a dielectric ceramic composition raw material powder having a small average particle diameter, a uniform composition, and excellent sintering characteristics by using a method other than the solid phase synthesis method. Method for producing raw material powder of porcelain composition, method for producing dielectric porcelain composition that can be efficiently produced in a short time at relatively low temperature using raw material powder for dielectric porcelain composition obtained by the method for producing raw material powder Another object of the present invention is to provide a dielectric ceramic composition having a small grain size obtained by the method for producing the dielectric ceramic composition and having excellent electrical characteristics (relative permittivity, dielectric loss, etc.).

[0014]

Means for Solving the Problems and Their Effects To achieve the above object, the dielectric ceramic composition according to the present invention (1)
Is (Ta ₂ O ₅ ) _{1-(x + y)} (TiO ₂ ) _x (Nb ₂ O ₅
) _Y (where (x + y) is 0.05 ≦ x + y ≦ 0.2)
(Value in the range of 0) and a grain size of 10 μm or less.

According to the dielectric ceramic composition (1), in the above composition formula, (x + y) is 0.05 ≦ x + y ≦ 0.20
, The grain size is 10 μm or less, the relative dielectric constant can be made as large as 70 to 200, and the dielectric loss can be kept as small as 0.026 or less. Further, since the grain size is as small as 10 μm or less, the thickness of the dielectric porcelain can be reduced even when an element such as a capacitor is manufactured, and an extremely small element can be manufactured. Also, a large-capacity capacitor can be manufactured.

Further, the method (1) for producing a raw material powder of a dielectric ceramic composition according to the present invention comprises the above-mentioned dielectric ceramic composition (1).
The raw material powder having an average particle size of 0.5 to 3
μm of Ta ₂ O ₅ and Ti having an average particle size of 0.5 to 3 μm.
O ₂ and / or Nb ₂ O ₅ having an average particle size of 0.5 to 3 μm
And (Ta ₂ O ₅ ) _{1- (x + y)} (TiO ₂ ) _x (Nb ₂
O ₅ ) _y (where (x + y) is 0.05 ≦ x + y ≦ 0.
20), into a ball mill so as to have a composition represented by the formula (1), and then wet-mixing in the ball mill, and after the wet-mixing step, 900 to 1200
A calcination synthesis step of performing calcination synthesis at 2 ° C. for 2 to 6 hours.

According to the method (1) for producing the raw material powder of the dielectric ceramic composition, the average particle diameter of the oxide used for producing the raw material powder is smaller than that of the conventional method. The calcining temperature can be greatly reduced to 900 to 1200 ° C. as compared with the conventional one, and calcining synthesis can be performed in a short time of 2 to 6 hours, the average particle size is small, the sintering activity is rich, and the The raw material powder of the dielectric ceramic composition that can be sintered can be efficiently and inexpensively manufactured.

Further, the method (1) for producing a dielectric porcelain composition according to the present invention is characterized in that the raw material powder having an average particle size of 1 to 5 μm produced by the method (1) for producing a raw material powder for the dielectric porcelain composition. After molding into a predetermined shape,
It is characterized by including a step of firing at 3 ° C. for 3 to 7 hours.

According to the method (1) for producing a dielectric ceramic composition, since the raw material powder produced by the method (1) for producing a raw material powder for the dielectric ceramic composition is used,
Raw material powder having an average particle diameter of 1 to 5 μm and smaller than that produced by a conventional solid phase synthesis method can be used. Firing can be performed in a short time and in a short time, and a dielectric ceramic composition having a small grain size and excellent electrical characteristics (relative permittivity, dielectric loss, etc.) can be efficiently and inexpensively manufactured.

The dielectric ceramic composition (2) according to the present invention comprises:
The dielectric ceramic composition (1) is characterized in that the grain size is 5 μm or less.

According to the dielectric ceramic composition (2), (x + y) is 0.0 in the composition formula of the dielectric ceramic composition (1).
5 ≦ x + y ≦ 0.20, the grain size is 5 μm or less, and the relative dielectric constant is 75 to 2
00, and the dielectric loss can be kept as small as 0.022 or less. Further, since the grain size is as small as 5 μm or less, the thickness of the dielectric porcelain can be made thinner even when an element such as a capacitor is manufactured, and an extremely small element can be manufactured. Further, a capacitor having a larger capacity can be manufactured.

Further, the method (2) for producing a raw material powder of the dielectric ceramic composition according to the present invention comprises the above-mentioned dielectric ceramic composition (2).
A solution containing a Ta compound, a solution containing a Ti compound and / or a solution containing an Nb compound, by mixing (Ta ₂ O ₅ ) _{1- (x + y)} (TiO ₂ ) _x (N
b ₂ O ₅ ) _y (where (x + y) is 0.05 ≦ x + y ≦
(Value in the range of 0.20), and then adding an aqueous alkali solution and reacting in an autoclave at a temperature of 100 to 200 ° C.

According to the method (2) for producing the raw material powder of the dielectric ceramic composition, the dielectric ceramic is prepared by a so-called hydrothermal synthesis method using an alkaline solution containing each element constituting the dielectric ceramic composition. Since the raw material powder of the composition (2) is produced, the average particle size is extremely small, about submicron,
The raw material powder having a high sintering activity and capable of sintering at a low temperature can be produced, and the reaction temperature of a relatively high temperature of 100 to 200 ° C. is adopted, so that the crystallinity is good and the sintering is excellent. It is possible to produce the raw material powder that is unlikely to undergo abnormal grain growth in the process.

In the method (2) for producing a dielectric ceramic composition according to the present invention, the average particle diameter produced by the method (2) for producing a raw material powder of the dielectric ceramic composition is 0.1 to 1 μm.
After forming the raw material powder into a predetermined shape,
It is characterized by including a step of firing at 0 ° C. for 2 to 4 hours.

According to the method (2) for producing the dielectric ceramic composition, since the raw material powder produced by the method (2) for producing the raw material powder for the dielectric ceramic composition is used,
A raw material powder having an average particle size of 0.1 to 1 μm, which is extremely small as compared with that produced by a conventional solid phase synthesis method, can be used. To efficiently and inexpensively produce a dielectric porcelain composition that can be fired in a short time of up to 4 hours, has a smaller grain size, and has excellent electrical characteristics (relative permittivity, dielectric loss, etc.). Can be.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a dielectric ceramic composition according to the present invention, a method for producing a raw material powder of the dielectric ceramic composition, and a method for producing a dielectric ceramic composition will be described.
The dielectric ceramic composition according to the embodiment (1) is (Ta ₂
O ₅ ) _{1-(x + y)} (TiO ₂ ) _x (Nb ₂ O ₅ ) _y (where (x + y) is a value in the range of 0.05 ≦ x + y ≦ 0.20) And the grain size is 10μm
It is as follows. That is, the dielectric porcelain composition is Ta
₂ O ₅ may contain only TiO ₂ ,
It may contain only b ₂ O ₅ . In addition, Ta ₂
O ₅ may contain both TiO ₂ and Nb ₂ O ₅ .

In the above dielectric ceramic composition, (x + y) in the above composition formula is 0.05 ≦ (x + y) ≦ 0.20
, The grain growth during firing is suppressed, and the dielectric ceramic composition has a small grain size and substantially uniform grain size. Further, by setting the grain size to 10 μm or less, the relative dielectric constant can be set to 70 to
The value can be as large as 200, and the dielectric loss can be kept as small as 0.026 or less. Further, since the grain size is as small as 10 μm or less, the thickness of the dielectric porcelain can be reduced even when an element such as a capacitor is manufactured, and an extremely small element can be designed and manufactured. Also, when manufacturing a multilayer capacitor, the thickness per layer can be reduced,
A large-capacity multilayer capacitor can be manufactured. Even in the case of a normal capacitor, a capacitor having a larger capacity can be manufactured by reducing the thickness.

If the grain size exceeds 10 μm, the electrical characteristics such as the relative dielectric constant deteriorate, and it becomes difficult to manufacture a small device. In the above composition formula, (x + y) is 0.05
If it is less than 0, or if (x + y) exceeds 0.20, the relative dielectric constant will be small.

Next, a method for producing a raw material powder of the dielectric ceramic composition according to the embodiment (1) will be described. In the method for producing a raw material powder for a dielectric ceramic composition according to the embodiment (1), the raw material powder is produced using a solid phase synthesis method. First, as an oxide of an element constituting the dielectric ceramic composition, Ta ₂ O ₅ having an average particle size of 0.5 to 3 μm is used.
And TiO ₂ having an average particle size of 0.5 to 3 μm and / or Nb ₂ O ₅ having an average particle size of 0.5 to 3 μm. The purity of these oxides is 99.9 wt% or more.

Next, as a wet mixing step, these oxides are mixed with (Ta ₂ O ₅ ) _{1-(x + y)} (TiO ₂ ) _x (Nb ₂ O
₅ ) _y (where (x + y) is 0.05 ≦ x + y ≦ 0.2
(Value in the range of 0) is charged into a ball mill filled with zirconia balls so as to have a composition represented by the formula (1), and usually, pure water is added, and then wet-mixed by the ball mill for about 12 to 24 hours.

Since the oxides are uniformly mixed by the wet mixing step, the powder is filtered and dried, and then, as a calcination synthesis step, calcination synthesis is performed at 900 to 1200 ° C. in the air for 2 to 6 hours. Do. The oxide powder has an average particle size of 0.3.
Since it is very small, such as ５5 μm, it reacts sufficiently in a short time of about 2 to 6 hours even at a low temperature such as 900 to 1200 ° C.,
(Ta ₂ O ₅ ) _{1- (x + y)} (TiO ₂ ) _x (Nb ₂ O ₅ )
_y (where (x + y) is a value in the range of 0.05 ≦ x + y ≦ 0.20) is produced. In addition, since the calcining synthesis temperature is low and the reaction time is short, no grain growth occurs when the oxide powder reacts, and the particles do not easily coagulate. However, since the powders are slightly agglomerated due to the calcination synthesis, the powder after the calcination synthesis is put into a ball mill filled with zirconia balls, and after adding pure water, the ball mill is again circulated for about 12 to 24 hours. By rotating, the powder is subjected to a crushing process.

The obtained raw material powder of the dielectric ceramic composition has a small average particle size of 1 to 5 μm, has a high sintering activity, and can be sintered at a low temperature.

According to the method for producing the raw material powder of the dielectric ceramic composition according to the embodiment (1), the average particle diameter of the oxide used for producing the raw material powder is smaller than that of the conventional method. Is as small as 0.5 to 3 μm,
The calcining temperature can be greatly reduced to 0 ° C. as compared with the conventional one, and the calcining synthesis can be performed in a short time of 2 to 6 hours, so that the raw material powder can be produced efficiently and inexpensively. The produced raw material powder has a small average particle size of 1 to 5 μm, has a high sintering activity, and can be sintered at a low temperature.

Next, a method of manufacturing the dielectric ceramic composition according to the embodiment (1) will be described. Embodiment (1)
In the production of the dielectric ceramic composition according to the above, the dielectric ceramic composition is produced using the raw material powder obtained by the above production method. The method for producing the dielectric ceramic composition,
It depends on the use of the dielectric ceramic composition. For example,
When manufacturing a single-plate capacitor, the average particle size is simply 1
A molded body is prepared by filling a raw material powder having a size of about 5 μm into a mold and pressing, and a firing process is performed as it is to produce a dielectric ceramic composition, and then electrodes and the like are formed. Also,
A binder made of a resin, a solvent, or the like is added to the raw material powder and mixed, followed by press molding in the same manner as described above,
There is also a method of producing a dielectric porcelain composition by performing a degreasing treatment and a baking treatment.

On the other hand, when manufacturing a multilayer capacitor or the like, a binder containing a large amount of a solvent or the like is added to the raw material powder to form a slurry, and a green sheet is prepared by a doctor blade method or the like, and then the green sheet is formed on the green sheet. After forming the conductor paste layers for the internal electrodes and laminating them, external electrodes are formed on both sides of the side surface of the laminate, and firing is performed.

In any of the above cases, the firing temperature was 13
The firing can be performed at a temperature as low as 40 to 1380 ° C. as compared with the conventional case, and the firing time can be as short as about 3 to 7 hours. According to the method of manufacturing a dielectric ceramic composition according to the embodiment (1), the raw material powder manufactured by the method of manufacturing a raw material powder of the dielectric ceramic composition according to the above embodiment (1) is used. Therefore, it is possible to use a raw material powder having an average particle diameter of 1 to 5 μm and a particle diameter smaller than that produced by a conventional solid phase synthesis method.
In addition, the firing can be performed in a shorter time of 3 to 7 hours at a lower temperature than in the past, and the dielectric ceramic composition can be efficiently and inexpensively manufactured. The manufactured dielectric porcelain composition has a small grain size of 10 μm or less and has excellent electrical characteristics (relative permittivity, dielectric loss, etc.).

Next, the dielectric ceramic composition according to the embodiment (2) will be described. In the dielectric ceramic composition, (x + y) in the above composition formula is 0.05 ≦ (x + y).
y) ≦ 0.20, the grain growth during firing is suppressed, the grain size is small, and the dielectric ceramic composition has grains of substantially uniform size. In addition, since the grain size is set to 5 μm or less, the relative dielectric constant can be set to a larger value of 75 to 200, and the dielectric loss can be kept smaller to 0.022 or less. Further, since the grain size is as small as 5 μm or less, the thickness of the dielectric porcelain can be further reduced even in the case of manufacturing an element such as a capacitor, and an extremely small element can be manufactured. In the case of manufacturing a multilayer capacitor, the thickness per layer can be further reduced, so that a multilayer capacitor having a larger capacity can be manufactured. Even for ordinary capacitors,
By further reducing the thickness, a capacitor having a larger capacity than in the conventional case can be manufactured.

Next, a method for producing a raw material powder of the dielectric ceramic composition according to the embodiment (2) will be described. In the method for producing the raw material powder of the dielectric ceramic composition according to the embodiment (2), the raw material powder is produced using a hydrothermal synthesis method. First, a solution containing a Ta compound and a solution containing a Ti compound and / or a solution containing an Nb compound as a raw material for hydrothermal synthesis are mixed with (Ta ₂ O ₅ ) _{1-(x + y)} (TiO ₂ ) _x
(Nb ₂ O ₅ ) _y (where (x + y) is 0.05 ≦ x +
(value in the range of y ≦ 0.20) in an autoclave.

As the Ta compound, the Ti compound and the Nb compound, chlorides and nitrates soluble in water or an organic solvent are preferable, but oxides which are hardly soluble in water or an organic solvent can also be used. . This is because the solubility increases under hydrothermal synthesis conditions and the reaction proceeds sufficiently. Examples of the Ta compound include TaCl ₅ , Ta
Br _5, Ta ₂ O ₅ and the like, examples of the Ti compound, for example TiCl _4, TiBr _4, TiO ₂ and the like, as the Nb compound, for example NbCl _5,
NbBr ₅ , Nb ₂ O _{5 and the} like can be mentioned. The total concentration of these compounds is preferably about 0.1 to 1.0 mol / liter. An aqueous alkali solution is added to a solution containing these compounds. Compounds for preparing the alkaline aqueous solution include KOH, NaOH, LiOH, N
H _3, and the like, pH of the solution in the autoclave to the alkali aqueous solution is added about 8 to 12 is preferred. The reaction temperature is preferably 100 to 200 ° C.,
00-180 ° C is more preferable. The reaction time is 1 to
About 10 hours are preferable.

According to the method for producing the raw material powder of the dielectric ceramic composition according to the embodiment (2), the alkaline solution containing each element constituting the dielectric ceramic composition is used, and the above-mentioned method is performed by a hydrothermal synthesis method. Since the raw material powder of the dielectric porcelain composition is manufactured, the average particle size is very small, about 0.1 to 1 μm,
The raw material powder which is rich in sintering activity and can be sintered at a low temperature can be produced. In an autoclave, 10
Because the reaction is performed at a relatively high temperature of 0 to 200 ° C,
A powder having good crystallinity is produced as compared with the alkoxide method and the like, and the powder is unlikely to cause abnormal grain growth during the sintering process.

Next, a method for producing the dielectric ceramic composition according to the embodiment (2) will be described. Embodiment (2)
In the production of the dielectric porcelain composition according to the above, a dielectric porcelain composition is produced using the raw material powder obtained by the above production method. The method for manufacturing the dielectric porcelain composition is substantially the same as the method for manufacturing the dielectric porcelain composition according to Embodiment (1) except for the firing conditions. Therefore, only the firing conditions will be described here. Firing temperature is 1320 to 1380 ° C
And the temperature is lower than in the conventional case, and the firing time may be as short as about 2 to 4 hours.

According to the method of manufacturing a dielectric ceramic composition according to the embodiment (2), the raw material powder obtained by the method of manufacturing a raw material powder of the dielectric ceramic composition according to the embodiment (2) is used. Is used, a raw material powder having an average particle size of 0.1 to 1 μm, which is extremely small in particle size as compared with that produced by a conventional solid phase synthesis method, can be used.
The sintering can be performed in a short time of 2 to 4 hours at a temperature lower than the conventional temperature of 20 to 1380 ° C., and the dielectric ceramic composition can be efficiently and inexpensively manufactured. The manufactured dielectric porcelain composition has a smaller grain size of 5 μm or less and is excellent in electrical characteristics (relative permittivity, dielectric loss, etc.).

[0043]

Examples and Comparative Examples Examples of the dielectric porcelain composition according to the present invention, a method for producing a raw material powder of the dielectric porcelain composition, and a method for producing the dielectric porcelain composition will be described below. In the following examples, the dielectric porcelain composition was manufactured using the raw material powders manufactured by the manufacturing method (solid-phase method, hydrothermal synthesis method) of the raw material powders of the dielectric porcelain composition according to the examples. , And its relative permittivity and dielectric loss were measured. As a comparative example, a dielectric ceramic composition having a composition out of the range (0.05> x + y, x + y> 0.20) was manufactured, or Ta ₂ containing TiO ₂ was produced by a conventional solid-phase synthesis method. O ₅ ,
Alternatively, Ta ₂ O ₅ containing Nb ₂ O ₅ was manufactured, and the relative permittivity and the dielectric loss were measured. The conditions are described below.

Examples 1 to 11 and Comparative Examples 1 to 7 (1) Production of Raw Material Powder (Solid Phase Synthesis Method) Average particle diameter of Ta ₂ O ₅ , TiO ₂ and Nb ₂ O ₅ : 1 μm
Purity of mTa ₂ O ₅ , TiO ₂ and Nb ₂ O ₅ : 99.9
wt% Compounding composition: as shown in Table 1 below.

Calcination synthesis temperature: 1000 ° C., calcination synthesis time: 3 hours Average particle size of raw material powder after calcination synthesis: 2 μm (2) Production of dielectric ceramic composition Conditions for press molding of raw material powder Molding method : Press molding of raw material powder as it is Molding pressure: 1000 kg / cm ² Shape of molded body Thickness: 1 mm, diameter: 15 mm Firing time and firing temperature: as shown in Table 1 below (3) Composition of manufactured dielectric ceramic Characteristics of object Pretreatment: After polishing both surfaces of the sintered body, gold electrodes are formed by evaporation Measurement of relative permittivity and dielectric loss Measurement equipment Impedance analyzer Hewlett-Packard (HP4192A) Grain size Etching process, scanning type Observation and measurement of the surface with an electron microscope (SEM) Composition of dielectric ceramic composition Assembled by IPC (emission spectroscopy) and X-ray diffraction analysis The dielectric ceramic composition of the same composition and it was confirmed that it is manufactured.

Relative dielectric constant, dielectric loss, and grain size: shown in Table 1 below [Examples 12 to 22, and Comparative Examples 8 to 14] (1) Production of Raw Material Powder (Hydrothermal Synthesis) Raw Material Solution TaCl ₅ ethanol solution, TiCl ₄ ethanol solution, NbCl ₅ ethanol solution Total concentration of the above compounds in the raw material solution (0.2 mol / l) Mixed composition: alkaline aqueous solution shown in Table 2 below: KOH (4 mol / l) alkaline aqueous solution pH: 12 Reaction temperature: 180 ° C., Reaction time: 3 hours Average particle size of raw material powder after hydrothermal synthesis: 0.1 μm (2) Production of dielectric ceramic composition Conditions for press molding of raw material powder Molding method: raw material powder as a press-molding a molding pressure: 2000 kg / cm ² green body shape thickness: 1 mm, diameter: 15 mm firing time, and firing temperature: Table 2 Shown (3) Characteristics of the produced dielectric porcelain composition pretreatment and measurement methods: Examples 1 to 11 and the relative dielectric constant was conducted in the same manner, dielectric loss, and the grain size: Table 2
(Comparative Examples 15 to 25) (1) Production of Raw Material Powder (Solid Phase Synthesis Method) Average particle size of Ta ₂ O ₅ and TiO ₂ : 5 to 10 μm Composition: Calcination synthesis shown in Table 3 below Temperature: 1350-1400 ° C, calcination synthesis time:
48 hours (2) Manufacture of dielectric porcelain composition Press molding conditions of raw material powder: Same as in Examples 1 to 11 Firing time and firing temperature: shown in Table 3 below (3) Manufactured dielectric Characteristics of porcelain composition Relative dielectric constant and dielectric loss: shown in Table 3 below [Comparative Examples 26 to 36] (1) Production of raw material powder (solid phase synthesis method) Ta ₂ O ₅ , TiO ₂ and Nb ₂ O the average particle size of _5: 5
10 μm Composition: shown in Table 4 below: Calcination synthesis temperature: 1350 to 1400 ° C., Calcination synthesis time:
48 hours (2) Manufacture of dielectric porcelain composition Press molding conditions of raw material powder: Same as in Examples 1 to 11 Firing time and firing temperature: shown in Table 4 below (3) Manufactured dielectric Characteristics of porcelain composition Relative permittivity and dielectric loss: shown in Table 4 below

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

As is clear from the results shown in Tables 1 to 4, in Examples 1 to 11, Ta ₂ O ₅ and Ti
Using fine particles of O ₂ and / or Nb ₂ O ₅ ,
By performing calcination synthesis in a short time, the average particle size is 2μ.
A raw material powder of the dielectric porcelain composition comprising m and fine particles could be produced, and by using the raw material powder, a dielectric porcelain composition could be produced at a low temperature in a short time. By adopting the above-described method for producing a dielectric porcelain composition, the produced dielectric porcelain composition has a grain size as small as 10 μm or less, a relative dielectric constant as large as 70 to 190, and a dielectric constant. Set the loss value to 0.
It could be as small as 26 or less.

In Examples 12 to 22, the raw material powder of the dielectric ceramic composition having an extremely fine particle having an average particle diameter of 0.1 μm was produced by a hydrothermal synthesis method using a soluble chloride. By using the raw material powder, a dielectric porcelain composition could be manufactured at a low temperature in a short time. Then, by employing the above-described method for producing a dielectric ceramic composition, the produced dielectric ceramic composition has a grain size as small as 5 μm or less, a relative dielectric constant value of 75 to 195, and a larger value. The value of the dielectric loss could be made as small as 0.20 or less.

On the other hand, Comparative Examples 1 to 7 and Comparative Examples 8 to 14
In the case of (1), the value of (x + y) in the above composition formula is 0.
Less than 5 or more than 0.2, the relative dielectric constant was small and the dielectric loss was large.

Comparative Examples 15 to 25 and Comparative Example 26
In the case of ~ 36, since the average particle diameter of the raw material oxide at the time of performing the calcination synthesis is large, the temperature of the calcination synthesis is set to 1350 ~.
The temperature had to be as high as 1400 ° C., and the time for the calcination synthesis had to be prolonged. In addition, since the raw material powder obtained by the calcination synthesis also has a large average particle size, the firing temperature is also 1400 ° C.
Alternatively, the dielectric ceramic composition had to be as high as 1450 ° C., and the relative dielectric constant and the dielectric loss of the obtained dielectric ceramic composition were inferior to those of the above examples. Also, it is considered that the grain size is considerably larger than in the case of the above embodiment.

Claims (6)

[Claims] 1. (Ta ₂ O ₅ ) _{1- (x + y)} (TiO ₂ ) _x
(Nb ₂ O ₅ ) _y (where (x + y) is 0.05 ≦ x +
(value in the range of y ≦ 0.20), and having a grain size of 10 μm or less. 2. Ta ₂ O ₅ having an average particle size of 0.5 to 3 μm.
And TiO ₂ having an average particle size of 0.5 to 3 μm and / or Nb ₂ O ₅ having an average particle size of 0.5 to 3 μm, (Ta ₂ O
₅ ) _{1- (x + y)} (TiO ₂ ) _x (Nb ₂ O ₅ ) _y (where
(X + y) is a value in the range of 0.05 ≦ x + y ≦ 0.20)
After putting into a ball mill so that the composition shown in
The method according to claim 1, further comprising a wet mixing step of performing wet mixing in the ball mill, and a calcination synthesis step of performing a calcination synthesis at 900 to 1200C for 2 to 6 hours after the wet mixing step. A method for producing a raw material powder for a dielectric ceramic composition. 3. An average particle size produced by the method for producing a raw material powder of a dielectric ceramic composition according to claim 2 is 1 to 5 μm.
After forming the raw material powder into a predetermined shape,
A method for producing a dielectric ceramic composition, comprising a step of firing at 80 ° C. for 3 to 7 hours. 4. The dielectric ceramic composition according to claim 1, wherein the grain size is 5 μm or less. 5. A solution containing a Ta compound and a solution containing a Ti compound and / or a solution containing an Nb compound,
₂ O ₅ ) _{1- (x + y)} (TiO ₂ ) _x (Nb ₂ O ₅ ) _y (where (x + y) is a value in the range of 0.05 ≦ x + y ≦ 0.20) and After mixing so as to obtain an aqueous alkali solution, 100 to 2
The method for producing a raw material powder of a dielectric ceramic composition according to claim 4, further comprising a step of reacting at a temperature of 00 ° C. 6. An average particle size produced by the method for producing a raw material powder of a dielectric ceramic composition according to claim 5 is 0.1 to 1
After molding the raw material powder of μm into a predetermined shape,
A method for producing a dielectric ceramic composition, comprising a step of firing at 380 ° C. for 2 to 4 hours.