JPH06239661A - Dielectric material porcelain composition for high-frequency wave and its production - Google Patents

Abstract

PURPOSE:To obtain a porcelain composition represented by a specific formula and improved in its dielectric constant by sintering a molded raw material in an oxygen-containing atmosphere. CONSTITUTION:BaCO3, Nd2O3, TiO2, Bi2O3, etc., as raw materials are. mixed with each other in a prescribed ratio in a wet state, dried, calcined at 1000-1200 deg.C, and further ground in a wet state. The produced slurry is dried, mixed with an organic binder, granulated, press-molded, and subsequently sintered in an oxygen-containing atmosphere to produce a dielectric material porcelain composition having a composition represented by E formula: xBaO.yNd2O3.zTiO2.vBi2O3 (0.130<x<0.160; 0.110<y<0.140; 0.600<z<0.650; 0.090<v<0.140; x+y+z+v=1), having a high dielectric constant, and useful for high frequency. The temperature dependency of the dielectric constant can be reduced by adding an Mn compound in an amount of 0<MnO2<=1.0g (in terms of the MnO2) to 100g of the composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency dielectric ceramic composition, and more particularly to a high frequency dielectric ceramic composition for a resonator, a filter, a capacitor, a circuit board or the like which is mainly used in a so-called microwave band. It relates to a composition.

[0002]

2. Description of the Related Art In recent years, antennas used in radio communication devices such as car phones, mobile phones, cordless phones, duplexers, and resonators used in voltage controlled oscillators, etc.
Alternatively, a high frequency dielectric ceramic is often used for a filter or the like used in a CATV tuner. In such a resonator or the like, by using a high dielectric constant material, the wavelength of the high frequency is shortened to 1 / (εr) ^1/2 (εr: relative permittivity) in vacuum, and It is generally known that a microwave of 1 wavelength, 1/2 wavelength, or 1/4 wavelength is confined in a high-frequency dielectric porcelain and is constructed in a small size so as to obtain a predetermined function and effect.

The characteristics required for such a high frequency dielectric ceramic are: (1) the electromagnetic wave has a wavelength of 1 in the dielectric.
/ (Εr) ^1/2 (where εr is the relative permittivity)
Since the larger the permittivity is, the smaller the permittivity can be made at the same resonance frequency. Therefore, the relative permittivity is as large as possible. (2) The permittivity loss in the high frequency band is small. There are three characteristics: low permittivity, that is, temperature dependence of relative permittivity (εr) is small and stable.

In the microwave band, when it is applied in a region of about 1 GHz, which is a relatively low frequency band used for car telephones, personal radios, cordless telephones, etc., the wavelength becomes considerably long, so that a small size resonator or the like is used. In order to achieve this, it is necessary that the dielectric ceramic composition has a considerably high relative dielectric constant.

Conventionally, as this type of dielectric ceramic composition, for example, BaO—Nd ₂ O ₃ —TiO ₂ —Bi ₂ O ₃ system composition, BaO—Nd ₂ O
_3- TiO ₂ -PbO-Bi ₂ O ₃ based compositions and the like are known.

For example, in Japanese Patent Laid-Open No. 63-100058, xBaO.yNd ₂ O ₃ .zTiO ₂ .vBi ₂ O ₃ (where x, y, z, v
Are 0.110 ≤ x ≤ 0.170 and 0.120 ≤ y ≤ 0.185, respectively.
, 0.630 ≤ z ≤ 0.710, 0.020 ≤ v ≤ 0.090, and 0.003 to 0.3% by weight of Mn with respect to the main component represented by x + y + z + v = 1)
Has been proposed, the dielectric ceramic composition has a high relative dielectric constant, the temperature dependence of the dielectric constant, resonance in the resonator. It is described that the temperature dependence of the frequency is small and a high no-load Q is exhibited.

[0007]

However, in the high frequency dielectric porcelain composition described in JP-A-63-100058, the relative permittivity is εr = 70 to 100.
However, if an attempt is made to obtain a material having a higher dielectric constant, there is a problem that the Q value suddenly deteriorates or the temperature characteristic deteriorates. Therefore, there is a limit to increase the dielectric constant to reduce the size of the resonator and the like.

This is because the composition disclosed in the above publication has v / x = 0.117 to 0.818 and v / y = 0.108 to 0.750.
, V / z = 0.028 to 0.142, and Bi ₂ O ₃ in the composition is
Therefore, the inventors of the present invention have the above-mentioned problems because the ratio of Bi ₂ O ₃ in the composition is v / x = 0.562 to 1.07, and v / y = 0.642. 1.27, v
By increasing /z=0.138 to 0.233, the relative permittivity (εr) is high, the fQ value that is the characteristic value of the dielectric loss is large, the temperature dependence (τf) of the permittivity is small, and It has been found that a high frequency dielectric porcelain composition that is stable and therefore has a small temperature dependence of the resonance frequency of a manufactured dielectric resonator or the like and that can be further miniaturized is completed the present invention. It is a thing.

[0009]

[Means for Solving the Problems] That is, the dielectric ceramic composition for high frequency according to the present invention is xBaO.yNd ₂ O ₃ zTiO ₂ .vBi ₂ O ₃
(In the formula, x, y, z, and v are 0.130 <x <0.16, respectively.
0, 0.110 <y <0.140, 0.600 <z <0.650, 0.090
<v <0.140 and a composition represented by x + y + z + v = 1) (1). Further, the high frequency dielectric ceramic composition according to the present invention is xBaO · yNd ₂ O ₃ · zTiO ₂ · vBi ₂ O ₃ (where x, y,
z and v are 0.130 <x <0.160 and 0.110 <y <, respectively.
0.140, 0.600 <z <0.650, 0.090 <v <0.140 and satisfying the condition of x + y + z + v = 1) as the main component, and the Mn compound is 0 <MnO ₂ converted to MnO ₂ with respect to 100 g of the main component. It is characterized by containing ₂ ≤ 1.0 g (2).

Further, the method for producing a high frequency dielectric ceramic composition according to the above (1) or (2) of the present invention is characterized by sintering in an atmosphere containing oxygen (3).

In the above-mentioned method for producing a dielectric ceramic composition for high frequencies, the term "in an oxygen atmosphere" means an air atmosphere or an oxygen-containing gas atmosphere containing a larger amount of oxygen than air.

[0012]

[Function] In the high frequency dielectric ceramic composition (1),
The value of x indicates the proportion of BaO 3 in the porcelain composition,
If the value of is less than 0.130, the fQ value is small, the temperature coefficient (τf) of the resonance frequency is large, and the value of x is 0.160.
When it is above, the relative dielectric constant (εr) does not become sufficiently large.

The value of y represents the proportion of Nd ₂ O ₃ in the porcelain composition. When the value of y is 0.110 or less, the fQ value becomes small and the temperature coefficient (τf) of the resonance frequency becomes large. When the value of y is 0.140 or more, the relative dielectric constant (εr) does not become sufficiently large.

The value of z indicates the proportion of TiO ₂ in the porcelain composition. If the value of z is 0.600 or less, the relative dielectric constant (ε
If r) is not sufficiently large and the value of z is 0.650 or more, the relative dielectric constant (εr) is not sufficiently large and the temperature coefficient (τf) of the resonance frequency is also large.

The value of v indicates the proportion of Bi ₂ O ₃ in the porcelain composition, and when the value of v is 0.090 or less, the relative dielectric constant (ε
r) is not sufficiently large, the fQ value is small, and if the value of v is 0.140 or more, the temperature coefficient (τf) of the resonance frequency is large.

In the high frequency dielectric porcelain composition (2) in which MnO ₂ is added to the porcelain composition, the fQ value is increased by several percent to tens of percent to improve the dielectric loss characteristics. Shows almost the same tendency as. However, the amount of MnO ₂ added
If it exceeds 1.0% by weight, it becomes difficult to obtain a dense sintered body, and the relative dielectric constant (εr) tends to be small.

According to the high frequency dielectric ceramic composition of the present invention, xBaO · yNd ₂ O ₃ · zTiO ₂ · vBi ₂ O ₃ (where x, y,
z and v are 0.130 <x <0.160 and 0.110 <y <, respectively.
0.140, 0.600 <z <0.650, 0.090 <v <0.140, and a composition represented by x + y + z + v = 1), high relative permittivity (εr), and dielectric loss characteristic value Is large, the temperature dependence (τf) of the dielectric constant is small, and it is stable against temperature changes.

According to the high frequency dielectric ceramic composition of the present invention, xBaO · yNd ₂ O ₃ · zTiO ₂ · vBi ₂ O ₃ (where x,
y, z and v are 0.130 <x <0.160 and 0.110 <, respectively.
y <0.140, 0.600 <z <0.650, 0.090 <v <0.140
Which satisfies the condition of x + y + z + v = 1) as the main component, and the Mn compound is added to 100 g of the main component.
In terms of MnO ₂ , 0 <MnO ₂ ≤ 1.0 g is contained, and the above (1)
Among the characteristics of the composition (1), the dielectric loss is reduced because the fQ value is further increased.

Further, according to the method for producing a high frequency dielectric ceramic composition according to the above (1) or (2) of the present invention, the sintering is performed in an atmosphere containing oxygen. )
Alternatively, among the characteristics of the high frequency dielectric ceramic composition described in (2), the relative dielectric constant (εr) is particularly large.

[0020]

EXAMPLES Examples and comparative examples of the high frequency dielectric ceramic composition according to the present invention will be described below.

High-purity BaCO ₃ , Nd ₂ O ₃ , TiO ₂ , Bi ₂ O ₃ ,
MnO ₂ was used as a raw material, weighed so as to have the composition shown in Table 1, and wet mixed in a pot mill. The raw materials are not limited to these, and other compounds can be used as long as they finally become the above oxide. For example, MnCO ₃ or the like may be used instead of MnO ₂ .

After drying the wet mixed material, 10
It was calcined at 00 to 1200 ° C. for 1 to 3 hours, and the calcined product was wet pulverized with a pot mill.

The slurry after the wet pulverization is dried, an appropriate amount of an organic binder (PVA) is added and granulated, and then 500 to 20
It was shaped into a column having a diameter of 22 mm and a thickness of 11 mm at a pressure of 00 kg / cm ² , and was fired at a temperature range of 1220 to 1360 ° C. for about 2 hours to obtain a dielectric ceramic.

Next, the same method as the above-mentioned method except that firing is carried out in an oxygen atmosphere having an oxygen content of about 80%,
Calcination and firing were performed under the conditions to obtain a dielectric ceramic.

It was confirmed by ICP emission analysis that the composition of the dielectric ceramics obtained by these methods was the same as the composition.

The dielectric porcelain was ground and polished to a diameter of 16 mm and a thickness of 7.5 mm, and the relative permittivity (εr), the Q value and the temperature coefficient (τf) of the resonance frequency (-2) at the resonance frequency of 2 to 3 GHz.
0 to 80 ° C) was measured by the dielectric cylinder resonator method. Since the Q value changes depending on the measurement frequency, it is represented by the fQ value, which is a substantially constant value. The results are shown in Tables 1 and 2 below.

[0027]

[Table 1]

[0028]

[Table 2]

In Tables 1 and 2, sample Nos. 1 to 14 are related to Examples within the scope of the present invention, and the relative dielectric constant (ε
r) is 100 or more, which is larger than the conventional one, and the fQ value is also
It is as high as 1500 GHz or more, and the temperature coefficient of resonance frequency (τ
f) is low and stable at less than ± 30 ppm / ° C. Sample
Nos. 15 to 31 relate to comparative examples outside the scope of the present invention, and any one of the relative permittivity (εr) and fQ value, the temperature coefficient (τf) of the resonance frequency, or the characteristics of two or more types described above. , Does not meet the required characteristics.

Further, in Nos. 32 to 37 showing the results of the examples in which the firing was carried out in an oxygen atmosphere, the firing was carried out in an oxygen atmosphere of 80%, so that all composition ranges were compared with the firing in air. Where fQ value and temperature coefficient of resonance frequency (τ
The relative permittivity (εr) is improved by 3 to 4 with almost no deterioration of f) and the like.

[0031]

The high frequency dielectric ceramic composition according to the present invention
In (1), xBaO ・ yNd ₂ O ₃・ zTiO ₂・ vBi ₂ O ₃ (wherein
x, y, z and v are 0.130 <x <0.160 and 0.11 respectively.
0 <y <0.140, 0.600 <z <0.650, 0.090 <v <0.1
It has a composition within the range of 40 and is represented by a value satisfying the condition of x + y + z + v = 1), and has a relative dielectric constant (ε
r) is 100 or more, which is larger than the conventional one, and the fQ value is also
High as 1500 GHz or more and temperature coefficient of resonance frequency (τ
f) also has small and stable characteristics of less than ± 30 ppm / ° C.

High frequency dielectric ceramic composition according to the present invention
In (2), xBaO ・ yNd ₂ O ₃・ zTiO ₂・ vBi ₂ O ₃ (wherein
x, y, z and v are 0.130 <x <0.160 and 0.11 respectively.
0 <y <0.140, 0.600 <z <0.650, 0.090 <v <0.1
The value of which satisfies the condition of x + y + z + v = 1) in the range of 40) and contains 0 <MnO ₂ ≦ 1.0 g of Mn compound in terms of MnO ₂ with respect to 100 g of the main component, and the relative permittivity All of (εr), fQ value, and temperature coefficient (τf) of resonance frequency have the characteristics higher than those of the high frequency dielectric ceramic composition of (1) above, and in particular, the fQ value becomes large and the dielectric loss becomes small.

Therefore, a resonator, a filter, or the like, which uses the high frequency dielectric ceramic composition of the present invention in the microwave band,
When it is used for a capacitor, a circuit board, etc., further miniaturization is possible, and it is possible to provide a stable component against temperature changes.

Further, in the method for producing a high frequency dielectric ceramic composition according to the above (1) or (2) according to the present invention, further sintering is performed in an atmosphere containing oxygen. High dielectric constant can be achieved.

[0035]

Claims (3)

[Claims] 1. xBaO.yNd ₂ O ₃ .zTiO ₂ .vBi ₂ O ₃ (where x,
y, z and v are 0.130 <x <0.160 and 0.110 <, respectively.
y <0.140, 0.600 <z <0.650, 0.090 <v <0.140
And a composition represented by a value satisfying the condition of x + y + z + v = 1). 2. xBaO · yNd ₂ O ₃ · zTiO ₂ · vBi ₂ O ₃ (where x,
y, z and v are 0.130 <x <0.160 and 0.110 <, respectively.
y <0.140, 0.600 <z <0.650, 0.090 <v <0.140
Which satisfies the condition of x + y + z + v = 1) as the main component, and the Mn compound is added to 100 g of the main component.
A high frequency dielectric ceramic composition containing 0 <MnO ₂ ≦ 1.0 g in terms of MnO ₂ . 3. The method for producing a high frequency dielectric ceramic composition according to claim 1, wherein the sintering is performed in an atmosphere containing oxygen.