JP2950672B2 - Dielectric porcelain composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric ceramic composition suitable for a dielectric resonator and a dielectric filter used in a high frequency region such as a microwave and a millimeter wave band.

[0002]

2. Description of the Related Art Conventionally, dielectrics have been applied to impedance matching of circuits, dielectric resonators, filters, and the like in the high-frequency region. There is a need for a dielectric having a large Q and a small variation in resonance frequency due to a temperature change.

A composite perovskite composition based on BaO—MgO—Ta ₂ O ₅ has a high unloaded Q value among existing materials.
However, there is a problem with the temperature change rate of the resonance frequency.

On the other hand, as a composition for reducing the temperature change rate of the resonance frequency, a composition system in which a part of MgO of BaO—MgO—Ta ₂ O ₅ is replaced by NiO (Japanese Patent Laid-Open No.
0-216407) and BaO-MgO-Ta
Some of the ₂ O ₅ system MgO, such as composition system was replaced with CoO has been proposed (JP 61-8804 JP).

[0005]

However, NiO and Co are added to the above-mentioned conventionally proposed MgO.
The substitutional composition system of O has a problem that the unloaded Q is reduced while the temperature change rate of the resonance frequency is reduced.

In order to solve the above-mentioned conventional problems, the present invention provides a BaO-MgO-Ta ₂ O ₅ based composite perovskite-type composition, which is capable of reducing the temperature change rate of the resonance frequency while maintaining a high no-load Q. It is an object of the present invention to provide a dielectric porcelain composition capable of achieving the following.

[0007]

In order to achieve the above object, the first dielectric porcelain composition of the present invention has a general formula B
_{a 1-XY (Mg 1-} Z Co Z) is represented by _X Ta _Y O _n,
For z in the range of 0.01 ≦ z ≦ 0.45, 0.13 ≦ x ≦ 0.1
9, which has a configuration in which 0.31 ≦ y ≦ 0.37 and 0.4800 ≦ x + y ≦ 0.4998 (where n is an arbitrary number).

[0008] The second dielectric ceramic composition of the present invention have the general formula _{Ba 1-XY (Mg 1-} Z Ni Z) X Ta Y O n
And for z in the range 0.01 ≦ z ≦ 0.40, 0.
12 ≦ x ≦ 0.18, 0.32 ≦ y ≦ 0.38, and 0.4800 ≦ x + y ≦
It has a configuration that is in the range of 0.4998 (where n is an arbitrary number).

Further, a third dielectric ceramic composition of the present invention has a general formula of Ba _{1 -XY} (Mg _{1 -Z- V} Co _Z Ni _V ) _X
Ta _Y O _n represented by, 0.01 ≦ z + v ≦ 0.40 , z> 0,
And for z and v in the range of v> 0, 0.13 ≦ x ≦ 0.
18 0.32 ≦ y ≦ 0.37 and 0.4800 ≦ x + y ≦ 0.4998 (where n is an arbitrary number).

[0010]

The first to third dielectric ceramic compositions of the present invention
According to the composition of the product, the composition formula Ba _1-XY(Mg_1-ZVCo
_ZNi_V)_XTa_YO_nDielectric porcelain composition represented by
And a specific range of z + v, x, y
It has a higher no-load Q and the temperature change rate of the resonance frequency:
τ_fIt is possible to obtain a small porcelain.

[0011]

【Example】

Example 1 Chemically high purity BaCO ₃ , Mg
O, CoO, using Ta ₂ O _5, performs a weighing a predetermined composition shown in Table 1 to Table 3, which was wet-mixing treatment using a ball mill.

This mixture is dried and calcined at 800 ° C. for 2 hours. The calcined powder is further pulverized by a ball mill, and after dehydration and drying, an appropriate amount of polyvinyl alcohol is added as a binder and 1 ton / cm ^2. To form a disk having a diameter of 8 mm and a thickness of 4 mm.

The molded body is heated at 1500 to 1550 ° C. for 12 hours.
The sintering was performed for a time to obtain a porcelain sample. The calcination was carried out in a state in which the molded body sample was placed in a platinum container sufficiently filled with a preliminarily calcined powder having the same composition in consideration of the evaporation of components at a high temperature.

For each porcelain sample obtained, 10 GHz
Dielectric constant at the frequency of: ε _r , unloaded Q value: Q, and temperature change rate of the resonance frequency at −50 ° C. to 50 ° C .:
τ _f (ppm / ° C.) was measured. The results are shown in Tables 1 to 3.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

As is clear from Tables 1 to 3, x + y <0.48
Is poor in sinterability with the composition x, and Q
Was significantly reduced, but a high Q value and a small τ _f were obtained in the range of 0.48 ≦ x + y ≦ 0.4998. The sample No. 33 of this example had the same composition as the sample No. 1 in JP-A-61-8804, and the sample No. 44 of this example was also the sample N of the publication.
o.2 and Sample No. 59 of this example are the same as Sample No. 5 of the publication.
And the same composition. In the conventional composition having a composition ratio of Ba and other than Ba of 1: 1, the Q value was significantly smaller than that in the composition range according to the present example.

When x <0.13 and z <0.01, τ _f is large, and when the composition is y <0.31 and z> 0.45, the Q value decreases, which is not practical. In the composition range according to the present embodiment, the Q value is 20,000 or more and the temperature change rate of the resonance frequency is 3 ppm / ° C. or less, which is a very good electrical characteristic.

Example 2 As a starting material, chemically pure BaCO ₃ , Mg
O, NiO and Ta ₂ O ₅ were used. Next, a predetermined composition shown in Tables 4 to 6 was weighed, and the mixture was wet-mixed using a ball mill. Hereinafter, test samples were obtained in the same manner as in Example 1.

Tables 4 to 6 show a frequency of 10 GHz for each composition.
Relative permittivity at ε _r , unloaded Q value: Q, and −50
Temperature change rate of resonance frequency between ℃ and 50 ℃: τ _f (ppm
/ ° C).

[0022]

[Table 4]

[0023]

[Table 5]

[0024]

[Table 6]

As is clear from Tables 4 to 6, x + y <0.48
Is poor in sinterability with the composition x, and Q
Was significantly reduced, and a high Q value and a small τ _f were obtained in the range of 0.48 ≦ x + y ≦ 0.4998. In addition, the sample N of the present example
o.131 has the same composition as sample No. 1 in JP-A-60-216407, and similarly, sample No. 143 of this example is sample No. 2 of the same publication.
The sample No. 158 of this example has the same composition as the sample No. 5 of the publication. In the conventional composition in which the composition ratio of Ba and other than Ba is 1: 1, Q is larger than that in the composition range according to the present embodiment.
The values were significantly smaller.

Further, when x <0.12 and z <0.01, τ _f is large, and when the composition is y <0.32 and z> 0.40, the Q value is lowered, so that it is not practical. In the composition range according to the present embodiment, the Q value was 20,000 or more, and the temperature change rate of the resonance frequency was 3 ppm / ° C. or less, which was a very good electrical characteristic.

Example 3 As a starting material, BaCO ₃ , M having a purity of 99.9% or more was used.
gO, was used CoO, NiO, the Ta ₂ O _5. Next, weighing was performed to obtain the compositions shown in Tables 7 to 9, and this was subjected to wet mixing using a ball mill. Hereinafter, test samples were obtained in the same manner as in Example 1.

Tables 7 to 9 show a frequency of 10 GHz for each composition.
Relative permittivity at ε _r , unloaded Q value: Q, and −50
Temperature change rate of resonance frequency between ℃ and 50 ℃: τ _f (ppm
/ ° C).

[0029]

[Table 7]

[0030]

[Table 8]

[0031]

[Table 9]

As is clear from Tables 7 to 9, each electric characteristic shows the same behavior as in Examples 1 and 2. Co and Ni
Shows the intermediate characteristics of the characteristics of each of Co and Ni alone depending on the composition ratio. That is, by adjusting the ratio of Co and Ni, it is possible to control τ _f required for an arbitrary ε _r .

As described above, a high-frequency device using a dielectric porcelain may have a temperature dependency caused by the device itself. In this case, the temperature dependency of the dielectric while maintaining the permittivity of the porcelain required for the device may be maintained. It is necessary to compensate for the temperature dependency as a whole. Therefore, controlling τ _f for an arbitrary ε _r is extremely useful in designing a high-frequency device having no temperature dependence. Therefore, the present invention is considered to be particularly effective in this technical field.

[0034]

As described above, according to the present invention, the composition
Formula Ba_1-XY(Mg_1-ZVCo_ZNi _V)_XTa_YO_n
Specific z + v, x, y in the dielectric ceramic composition represented by
, Especially 0.4800 ≦ x + y ≦ 0.4998
As a result, high unloaded Q value and low resonance frequency
Dielectric porcelain that simultaneously satisfies the rate of change
Becomes

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-8804 (JP, A) JP-A-63-19706 (JP, A) JP-A-63-152815 (JP, A) 5357 (JP, A) JP-A-4-4509 (JP, A) JP-A-3-171507 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01B 3/12 312 C04B 35/495 H01G 4/12 415 H01P 11/00

Claims (3)

(57) [Claims] 1. The general formula Ba _{1 -XY} (Mg _{1 -Z} Co _Z ) _X T
represented by a _Y O _n, to z in the range of 0.01 ≦ z ≦ 0.45, 0.13 ≦ x ≦ 0.19,0.31 ≦ y ≦ 0.37, and 0.4800 ≦
A dielectric ceramic composition in the range of x + y ≦ 0.4998 (where n is an arbitrary number). 2. The general formula Ba _{1 -XY} (Mg _{1 -Z} Ni _Z ) _X T
represented by a _Y O _n, to z in the range of 0.01 ≦ z ≦ 0.40, 0.12 ≦ x ≦ 0.18,0.32 ≦ y ≦ 0.38, and 0.4800 ≦
A dielectric ceramic composition in the range of x + y ≦ 0.4998 (where n is an arbitrary number). 3. A compound of the formula Ba _{1 -XY} (Mg _{1 -ZV} Co _Z Ni)
_V) represented by _{X Ta Y O n, 0.01 ≦} z + v ≦ 0.40, z
> 0 and for z and v in the range v> 0, 0.13 ≤
x ≦ 0.18, 0.32 ≦ y ≦ 0.37 and 0.4800 ≦ x + y ≦ 0.49
A dielectric ceramic composition in the range of 98 (where n is an arbitrary number).