JPH1112036A - Production of dielectric ceramic electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing the subject electronic parts with high QE value. SOLUTION: The electronic parts can be obtained by baking a dielectric ceramic composition of the composition formula xZrO2 -yTiO2 -zA(1+w)/3 Nb(2-w)/3 O2 ; wherein, A is at least one kind of component selected from the group consisting of Mg, Co, Zn, Ni and Mn, and (x), (y), (z) and (w) satisfy the relationships described below; furthermore, the above composition is controlled in the content of Ca as an impurity to <=0.01 wt.% in terms of CaO; 0.10<=(x)<=0.60, 0.20<=(y)<=0.60, 0.01<=(z)<=0.70, and 0<=(w)<=1.50 (the respective units for (x), (y) and (z) are molar fractions, and (w) denotes an absolute number). QE = central frequency/(wide range side frequency corresponding to resonance resistance minus 3dB) - (narrow range side frequency corresponding to resonance resistance minus 3dB).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a dielectric ceramic electronic component used as a dielectric resonator in a high frequency region such as a microwave and a millimeter wave.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No.
_{As a} dielectric porcelain composition with a large _E value and a large relative dielectric constant, and which can arbitrarily adjust the temperature coefficient of the resonance frequency over a wide range,
As an impurity in the material component, Ca is converted to CaO to be 0.1%.
It is disclosed that the content is between 0.4 and 0.05%.

[0003]

[SUMMARY OF THE INVENTION The, even more Q _E value of the conventional dielectric ceramic composition high Q _E value of the dielectric resonator is desired in recent years.

[0004]

In order to achieve the above object, a dielectric ceramic composition for a dielectric ceramic electronic component of the present invention has a composition formula of xZrO ₂ -yTiO ₂ -zA.
_{When represented by (1 + w) / 3} Nb _{(2-w) / 3} O ₂ , the symbol A is ΔM
g, Co, Zn, Mn}, at least one component selected from the group consisting of x, y, z, and w in the following range. it is possible to obtain a high excellent dielectric resonator dielectric ceramic electronic component of Q _E value by firing a dielectric ceramic composition was controlled to 0.01% or less.

0.10 ≦ x ≦ 0.60 0.20 ≦ y ≦ 0.60 0.01 ≦ z ≦ 0.70 0 ≦ w ≦ 1.50 (where x, y and z are mole fractions, w Indicates anonymous number)

[0006]

The invention according to claim 1 of the embodiment of the present invention is a composition formula _{xZrO 2 -yTiO 2 -zA (1 +} w) / 3 Nb
When represented by _{(2-w) / 3} O ₂ , the symbol A is ｛Mg, Co, Z
at least one component selected from the group consisting of n, Ni, Mn}, and x, y, z, and w in the following ranges:
Further, Ca contained as an impurity is converted into CaO to be 0.1%.
This is a method for producing a dielectric ceramic electronic component in which the dielectric ceramic composition is controlled to 01% or less.

0.10 ≦ x ≦ 0.60 0.20 ≦ y ≦ 0.60 0.01 ≦ z ≦ 0.70 0 ≦ w ≦ 1.50 (where x, y and z are mole fractions, w Represents an anonymous number) Ca in the material component is converted to CaO, and 0.04 to 0.05
% Of the dielectric porcelain composition contained in JP-A-6-2.
No. 95619, in the present invention,
Ca is used as an impurity in the entire dielectric porcelain composition.
By controlling to 0.01% or less in terms of, it was experimentally found that the _QE value was further improved and the relative dielectric constant was not reduced.

According to a second aspect of the present invention, there is provided the method for producing a dielectric ceramic electronic component according to the first aspect, wherein the starting material has a particle size of 1 μm or less,
By using a component of the dielectric ceramic composition having a particle diameter of 1 μm or less, the relative dielectric constant, Q
_A sintered body having a high _E can be obtained, and an energy saving effect can be obtained. When a powder having a particle diameter of 1 μm or more is used, the sintered particles of the dielectric ceramic sintered body become large, or abnormal grain growth occurs partially, and the dielectric ceramic Q _E value for a dielectric resonator decreases. There is a problem.

According to a third aspect of the present invention, there is provided the method for producing a dielectric ceramic electronic component according to the first aspect, wherein the dielectric ceramic composition is fired in an oxygen atmosphere. the by firing in an oxygen atmosphere, it can be dielectric ceramic interior, improved sintered density becomes uniform external sintering to obtain a dielectric ceramic higher Q _E value.

The invention according to claim 4 of the present invention is characterized in that the dielectric porcelain composition is calcined and then finely pulverized to 1 μm to 1.2 μm. A method for producing a dielectric ceramic electronic component according to the above, wherein the calcined material is pulverized to 1 μm to 1.2 μm to obtain a dielectric ceramic having a high Q _E value by improving the density of the sintered body after firing. Can be obtained.

The invention according to claim 5 of the present invention uses a dielectric porcelain composition in which the amount of Ca contained in the medium material used for mixing and grinding is 1% or less in terms of CaO. The method for producing a dielectric ceramic electronic component according to any one of claims 1, 2, and 4, wherein the method comprises mixing a calcined dielectric ceramic composition and a medium used for grinding. This is to prevent a decrease in Q _E value by the incorporation of the above CaO.

[0012] The invention according to claim 6 of the present invention is characterized in that the impurity Ca contained in the sheath material for firing the dielectric ceramic composition is Ca.
Is used in which 1% or less is converted into CaO.
The method for producing a dielectric ceramic electronic component according to any one of claims 1 to 5, wherein CaO contained as an impurity in a sheath material for firing the dielectric ceramic diffuses into the dielectric ceramic sintered body during firing. This is to prevent a decrease in Q _E value by.

Hereinafter, an embodiment of the present invention will be described. (Embodiment 1) FIG.
A graph of the obtained empirically the relationship between aO amount and Q _E value.

The starting material is ZrO ₂ , TiO ₂ , MgO, Co, which is chemically high-purity and whose particle diameter is controlled to 1 μm or less.
_{O, ZnO, NiO, Nb 2} O 5, MnCO 3, and Ca
O powder was weighed so as to have the composition shown in (Table 1), and then placed in a polyethylene ball mill.
a stabilized zirconia cobblestone having an aO content of 1% or less;
After adding ethanol as a solvent and mixing and drying for about 20 hours, the mixture was placed in an alumina crucible having a CaO content of 1% or less as impurities and calcined at 900 ° C. for 2 hours in the atmosphere. Next, the calcined powder was pulverized in the same manner as in the mixing to obtain a material powder having a particle diameter of 1 μm to 1.2 μm.

[0015] After adding an organic binder to the material powder and mixing, the mixture is sieved through a 32 mesh sieve.
It was formed into a disc having a diameter of 13 mm and a thickness of 6 to 8 mm at ton / cm ² . Next, the compact was placed in an alumina sheath having an amount of CaO as an impurity of 1% or less, and calcined in the atmosphere at a temperature of 1400 ° C. for 4 hours to obtain sintered bodies of samples No. 1 to 24 shown in (Table 1). I got After polishing both surfaces of the obtained sintered body, the relative dielectric constant (ε) was measured at a measurement frequency of 4 to 5 GHz by a dielectric resonator measuring method while electrodes were not provided on both surfaces.
r), performs a measurement of the resonant frequency temperature coefficient of Q _E, and Q _E in a temperature range of -25 to 85 ° C. (.tau.f), showed the results (Table 1) and FIG. Note that Q _E is the center frequency ± 3 dB
(Equation 1) and the relative dielectric constant were obtained from (Equation 2). Further, since the details are disclosed in Japanese Patent Application Laid-Open No. 6-295819, in the first embodiment, the amount of the impurity CaO with respect to the representative composition was examined.

[0016]

(Equation 1)

[0017]

(Equation 2)

[0018]

[Table 1]

Sample numbers 3, 7, 11, 1 in Table 1
5, 19 and 23 used data of CaO contained as an impurity disclosed in Japanese Patent Application Laid-Open No. 6-295609.

(Table 1) As is clear from FIG.
Amount of O Whereas Q _E value abruptly decreases according to a number consisting of 0.05%, the added amount of CaO is 0.01%
When the number is smaller, it can be seen that the _QE value is higher than the conventional product by 30% or more. No of this high Q _E value
Nos. 3, 4, 7 and 8 with Q _E values as low as 1, 25 and 26
X-ray diffraction analysis of the sintered body showed that CaO was 0.05%
In the above case, a segregated phase of CaO appears in the sintered body. The segregation phase is believed that lowering the Q _E value. Therefore, C that is acceptable as an impurity for the dielectric ceramic composition
The amount of aO is preferably 0.01% or less, and within this range, the Q value can be maintained without impairing the relative permittivity and the temperature coefficient of the resonance frequency.
A dielectric ceramic for a dielectric resonator having an excellent _E value can be obtained. If the starting material used has a particle size of more than 1 μm, the resulting sintered body may have a large crystal particle size or partially grow abnormal grains. loss Q _E value of the dielectric ceramic becomes problems lower increases. Therefore, controlling the particle size of the starting material to 1 μm or less is an essential condition. Further, the amount of CaO contained as an impurity in the zirconia ball as a medium used for mixing and grinding is 1%.
By weight, mixing, since the dielectric ceramic Q _E value CaO increases the zirconia balls is mixed in with the dielectric ceramic material wear problem lowered occurs during grinding, zirconia content of 1% or less of CaO The use of boulders is a prerequisite. The same applies to the sheath for firing.

(Embodiment 2) Sample No. 2 of Embodiment 1
Material powder, outer diameter 65mm, inner diameter 20mm, height 40
mm at a molding pressure of 1 to ² ton / cm ² at a temperature of 1400 ° C. in the air and in an oxygen atmosphere.
The firing was performed for a time. The resulting sintered body to the first embodiment and the resonance frequency in the same measurement method, and measurement of Q _E values, performs a measurement of the sintered body density Archimedes method, and the results are shown in (Table 2).

[0022]

[Table 2]

As is clear from Table 2, the sample No. 25 fired in an oxygen atmosphere has a Q · f ₀ value higher than that of No. 26,
It can be seen that both the density of the sintered body and the density of the sintered body are increased by about 15%. This is firing the molded body in an oxygen atmosphere, the molded body internal to oxygen diffusion and uniform sintering is performed sintered density is increased sufficiently during calcination, becomes high Q _E resulting sintered body It seems to have been. Sample No. 26 fired in the air had a different density between the inside and the outside of the sintered body, and when observed with a metallographic microscope, it was found that the inside was porous. The large element produced here is mainly used for a dielectric filter for a base station. In this case, particularly high reliability is required. For this reason, in the case of a non-homogeneous sintered body, reliability such as thermal shock resistance and moisture resistance is reduced, which is not preferable. Therefore, it is preferable that the large-sized dielectric ceramic is fired uniformly, particularly in an oxygen atmosphere, to produce a highly reliable dielectric ceramic for a dielectric resonator.

(Embodiment 3) Sample No. 2 of Embodiment 1
After mixing and calcining the material compositions of the above, the pulverization time was changed and material powders having the particle diameters shown in Table 3 were prepared. To
Molding was performed at a molding pressure of 1-2 ton / cm ² . Thereafter, baking was performed in the atmosphere at a temperature of 1400 ° C. for 4 hours. And density of the sintered body obtained, an inner peripheral surface, the dielectric constant of the dielectric ceramic were electrode baking at a temperature of silver paste is applied to the outer peripheral surface 800 ° C. of the sintered body, carrying out the Q _E value form Measure in the same way as 1
The results are shown in (Table 3).

[0025]

[Table 3]

[0026] As is clear from (Table 3), the dielectric constant of the grinding particle size of the material powder is sintered bodies, sintered density, it is found that particularly has a significant effect on Q _E value. Sample No. 27, 2
The sintered body density of 8 small is considered to have influenced to be poor packing at the time of molding since the diameter powder particles is small, so that Q _E value seems to have lowered.
No29 and 30 milled particle diameter of 1~1.2μm contrast is large sintered density, Q _E also increases accordingly. However, when the pulverized particle diameter is larger than 1.5 μm as in Nos. 31 and 32, both the relative dielectric constant and the Q _E value begin to decrease, which is not preferable. This is presumably because the sinterability deteriorates as the size of the pulverized particles increases.

The above, by employing the manufacturing process to manage milled particle size to a certain size as in the third embodiment, Q _E value, high dielectric constant excellent dielectric resonator dielectric ceramic It turns out that it is possible to obtain.

[0028]

As described above, according to the present invention, xZrO ₂ -yTiO ₂ -zA _{(1 + w ) / 3} Nb _{(2-w) / 3} O
When expressed in _2, symbol A is {Mg, Co, Zn, Ni , M
At least one component selected from the group consisting of n｝, and x, y, z, and w are in the following ranges, and Ca further contained as an impurity is converted to CaO to 0.0
By sintering a dielectric ceramic composition is controlled to 1% or less, it is possible to obtain the dielectric constant, the Q _E value and resonance frequency temperature characteristic superior dielectric resonator dielectric ceramic.

0.10 ≦ x ≦ 0.60 0.20 ≦ y ≦ 0.60 0.01 ≦ z ≦ 0.70 0 ≦ w ≦ 1.50 (where x, y and z are mole fractions, w Indicates an innumerable number.) Further, by controlling the particle size of the starting material, the crushed particles after calcination, and the firing atmosphere, the _QE value can be further increased, which is a factor of the dielectric resonator. It contributes to high performance and has a large industrial use value.

[Brief description of the drawings]

FIG. 1 is a diagram representing the relationship between the CaO addition amount and Q _E values for the dielectric ceramic composition

Claims (6)

[Claims] 1. A composition formula of xZrO ₂ -yTiO ₂ -zA
_{When represented by (1 + w) / 3} Nb _{(2-w) / 3} O ₂ , the symbol A is ΔM
g, at least one component selected from the group consisting of Co, Zn, Ni, and Mn, and x, y, z, and w are within the following ranges, and Ca contained as an impurity is converted to CaO. A method for producing a dielectric ceramic electronic component, in which a dielectric ceramic composition controlled to 0.01% or less is fired. 0.10 ≤ x ≤ 0.60 0.20 ≤ y ≤ 0.60 0.01 ≤ z ≤ 0.70 0 ≤ w ≤ 1.50 (where x, y, z are mole fractions, w is an anonymous number) Indicates) 2. The method for producing a dielectric ceramic electronic component according to claim 1, wherein the starting material component has a particle size of 1 μm or less. 3. The method for producing a dielectric ceramic electronic component according to claim 1, wherein the dielectric ceramic composition is fired in an oxygen atmosphere. 4. After calcination of the dielectric porcelain composition, it is 1 μm or more.
The method for producing a dielectric ceramic electronic component according to any one of claims 1 to 3, wherein a powder material finely pulverized to 1.2 µm is used. 5. The method according to claim 1, wherein the content of Ca contained in the medium material used for mixing and pulverizing the dielectric ceramic composition is 1% or less in terms of CaO. A method for manufacturing a dielectric ceramic electronic component according to claim 4. 6. The dielectric ceramic composition according to any one of claims 1 to 5, wherein Ca used as an impurity contained in the sheath material for firing of the dielectric ceramic composition is 1% or less in terms of CaO. Of manufacturing a dielectric ceramic electronic component.