JP3024300B2 - High frequency dielectric ceramic composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dielectric porcelain composition,
In particular, the present invention relates to a high frequency dielectric ceramic composition used for a dielectric resonator or the like in a high frequency region.

[0002]

2. Description of the Related Art Dielectric porcelain is widely used in dielectric resonators and dielectric substrates in high-frequency regions such as microwaves and millimeter waves. Examples of this kind of dielectric ceramic composition for high frequency include, for example, JP-A-60-1243.
No. 05, the formula: Ba (Sn _X
Mg _Y Ta _Z) is represented by _{O 7/2-X / 2-3Y} / 2, X, Y, Z
However, there are compositions in the range of 0.04 ≦ X ≦ 0.26, 0.23 ≦ Y ≦ 0.31, 0.51 ≦ Z ≦ 0.65 (where X + Y + Z = 1), respectively.

[0003] This conventional high frequency dielectric porcelain composition comprises:
The dielectric ceramic composition has a large relative permittivity and a large Q value in a high frequency region and has a good temperature coefficient of resonance frequency.

[0004]

However, in recent years, the frequency range used has tended to be higher, and a dielectric ceramic composition for a dielectric resonator or a dielectric substrate having a Q value as large as possible has been developed. The above-mentioned conventional high frequency dielectric porcelain composition has not been able to sufficiently meet the demand.

The present invention solves the above-mentioned problems, and has a higher Q value, a higher relative dielectric constant, and better resonance in a high-frequency region than conventional dielectric ceramic compositions. An object of the present invention is to provide a high-frequency dielectric ceramic composition having a frequency temperature coefficient.

[0006]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies and found that Ba (Sn _X Mg _Y Ta).
_Z ) In the composition represented by O _W , by adjusting the composition so that X, Y, and Z are in a predetermined ratio,
The inventors have found that a dielectric ceramic composition for high frequency having excellent characteristics such as Q value can be obtained, and have completed the present invention.

That is, the high frequency dielectric ceramic composition of the present invention has the formula: Ba (Sn _X Mg _Y Ta _Z ) O _W (where
X + Y + Z = 1, W = arbitrary number), X, Y, and Z represent four points A (X, Y, Z) and B (X, Y, Z) shown below, respectively. ), C (X, Y, Z), D
(A, 0.001, 0.360, 0.640) B (0.001, 0.300, 0,700) C (0.010, 0.300, 0.690) D (0.010, 0.360) , 0.630).

[0008] In the high frequency dielectric ceramic composition of the present invention, the ratio of X, Y, Z is limited to the above range.
The composition outside the line connecting A and D shown in FIG.
When Y> 0.36) and when the composition is outside the line connecting B and C (that is, Y <0.30), sintering becomes unstable and a stable dielectric porcelain is obtained. In addition, in the composition outside the line connecting C and D in FIG. 1 (that is, X> 0.01), the obtained Q value is small, and the composition outside the line connecting A and B in FIG. (For example, X
<0.001) is not preferable because the Q value is small and the temperature coefficient of the resonance frequency increases to the positive side. Note that the value of W fluctuates somewhat depending on the ratio of X, Y, and Z. For example, the value of W is calculated by the following equation: (7 / 2−X / 2−
3Y / 2).

[0009]

EXAMPLES Examples of the present invention will be described below along with comparative examples to further clarify the features of the present invention.

The high frequency dielectric ceramic compositions of Examples and Comparative Examples of the present invention (that is, the formula: Ba (Sn _x Mg _Y Ta)
In preparing the represented compositions) with _Z) O _W is
First, high purity BaCO ₃ , SnO ₂ , MgCO ₃ , Ta ₂
O ₅ is prepared, and these raw materials are weighed so as to have the composition shown in Table 1 below, placed in a ball mill, and wet-mixed for 16 hours. In Table 1, the values of X, Y, and Z indicate molar ratios.

Then, after drying this mixed raw material, 13
A calcined product is obtained by calcining at 00 ° C. for 3 hours. Then, this calcined product is put into a ball mill together with water and an organic binder and wet-pulverized for 4 hours. After drying this ground product, 5
Through a 0-mesh sieve, the powder was adjusted to a predetermined particle size, and the obtained powder was pressed at a pressure of 2000 kg / cm ² at a diameter of 12 mm.
It is formed into a disk having a thickness of 5 mm. And this molded product is
Each sample of Examples and Comparative Examples was obtained by firing at 600 ° C. for 20 hours in the air.

[0012] For each sample of Examples and Comparative Examples were prepared as described above, together with measuring the relative dielectric constant epsilon _r, Q value at a frequency 10 GHz, the temperature coefficient of the resonant frequency from temperature coefficient of the resonant frequency tau _f Was calculated. Table 1 shows the results.

[0013]

[Table 1]

In Table 1, samples marked with * are samples outside the scope of the present invention, that is, comparative examples.
Others are samples within the scope of the present invention, that is, samples of Examples.

From Table 1, as shown in Sample No. 1, A,
Composition outside the line connecting D (ie, Y> 0.36)
In the case of sintering, sintering became unstable, stable dielectric ceramics could not be obtained, and characteristics could not be measured. This means that a dielectric porcelain (that is, a sintered body) that can be used as a high-frequency dielectric porcelain cannot be obtained.

Also, when the composition is outside the line connecting B and C in FIG. 1 (ie, Y <0.30) as in sample No. 5, the sintering becomes unstable similarly to sample No. 1. As a result, stable dielectric porcelain could not be obtained, and characteristics could not be measured.

Further, as shown in sample No. 9, C and D in FIG.
It can be seen that a composition outside the line connecting (i.e., X> 0.01) cannot obtain a sufficiently large Q value.

As shown in Samples Nos. 2, 4 and 12, FIG.
Outside the line connecting A and B (ie, X <0.001)
Then, the Q value is small and the temperature coefficient of resonance frequency τ _f
Is unfavorably increased in the positive direction.

On the other hand, Sample Nos. 3, 6, 7, 8, 10, 1
As shown in FIGS. 1 and 13, X, Y and Z correspond to four points A,
A sample in a molar ratio region surrounded by B, C, and D, that is, a sample within the scope of the present invention has a higher Q value and a better temperature coefficient of resonance frequency than the sample of the comparative example. it has androgynous the tau _f, the dielectric constant is also a comparable or higher in comparison with Comparative example, it is found to have a practically sufficient size.

[0020]

According to the present invention as described above, high frequency dielectric ceramic composition of the present invention, the _{Ba (Sn X Mg Y Ta Z} ) dielectric ceramic composition represented by O _W, X, Y, Z values Is adjusted so as to fall within the predetermined range surrounded by A, B, C, and D described above, so that it has a high Q value that cannot be obtained with the conventional dielectric ceramic composition, and has a high Q value. A high frequency dielectric ceramic composition having a relative dielectric constant and a good temperature coefficient of resonance frequency can be obtained.

That is, according to the present invention, it is possible to provide a high-frequency dielectric ceramic composition useful for applications such as a dielectric resonator and a dielectric substrate.

[Brief description of the drawings]

FIG. 1 is a view showing a composition range of a dielectric ceramic composition for high frequencies of the present invention.

[Explanation of symbols]

 A, B, C, D Each point that defines the composition range, …… Each sample No.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01B 3/10-3/14 C04B 35/00-35/22 CA (STN)

Claims (1)

(57) [Claims] 1. A _{formula: Ba (Sn X Mg Y Ta} Z) O W ( however, X + Y + Z = 1 , W = any number) in the dielectric ceramic composition represented by, X, Y, Z, respectively, or less The four points A (X, Y, Z) and B (X, Y,
Z), C (X, Y, Z), D (X, Y, Z), in a region of a molar ratio surrounded by a high frequency dielectric ceramic composition A (0.001, 0.360, 0.640) B (0.001, 0.300, 0,700) C (0.010, 0.300, 0.690) D (0.010, 0.360, 0.630).