JPH0971457A - Dielectric porcelain composition for high-frequency wave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dielectric porcelain composition for high-frequency waves excellent in high frequency property with low loss. SOLUTION: This invention relates to a dielectric porcelain composition for high-frequency having high Q value in the microwave and millimeterwave range. The composition is represented by the general formula: ((MgO)1-x (TiO2 )x )1-y (MnO)y (where X is 0.2<=X<=0.55 and Y is 0.002<=Y<=0.01). This porcelain composition has higher Q value compared with the conventional material to which no MnO is added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency (microwave) dielectric ceramic composition, and more particularly to a high frequency dielectric ceramic composition having a high Q value in a high frequency region such as microwave or millimeter wave.

[0002]

2. Description of the Related Art In recent years,
Along with higher frequency and higher performance of electronic devices such as high frequency (microwave) dielectric antennas and dielectric resonators, there is a need for a dielectric ceramic composition having low loss in the microwave range.

Conventionally, as this type of dielectric ceramic composition, a MgO-TiO ₂ -based dielectric ceramic composition has been known (Electronic Ceramics 1988, Vo.
l. 19, 92). For example, MgO: TiO ₂ = 1:
In the dielectric ceramic composition of 1 (chemical formula MgTiO ₃ ), a value of Q = 22000 was obtained at a frequency f = 5 GHz.

However, recently, a material having a higher Q in the microwave region is required.

The present invention has been made in view of the above problems, and an object thereof is to provide a dielectric ceramic composition for high frequencies, which has low loss and excellent high frequency characteristics.

[0006]

High frequency dielectric of the present invention
The porcelain composition has the general formula ((MgO)_1-X(Ti
O₂) _X)_1-Y(MnO)_YThe value of X is 0.2
≦ X ≦ 0.55 and the value of Y is 0.00
The range is 2 ≦ Y ≦ 0.01.

The high frequency dielectric ceramic composition of the present invention has the general formula ((MgO) _1-X (TiO ₂ ) _X ) _1-Y (M
nO) _Y , the value of X is in the range of 0.3 ≦ X ≦ 0.55, and the value of Y is 0.002 ≦ Y ≦ 0.007.
Is in the range of

According to the dielectric ceramic composition for high frequency of the present invention, the general formula ((MgO) _1-X (TiO ₂ ) _X ) _1-Y (M
nO) _Y , the value of X is in the range of 0.2 ≦ X ≦ 0.55, and the value of Y is in the range of 0.002 ≦ Y ≦ 0.01. A high Q value can be obtained by comparison.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the high frequency dielectric ceramic composition of the present invention will be described below with reference to FIGS.

First, the manufacturing process of the high frequency dielectric ceramic composition of this example will be described with reference to FIG. In the first weighing step 1, high-purity TiO ₂ , MgO and MnO are weighed so as to obtain a porcelain composition having a desired composition.
Next, in the primary mixing step 2, the composition weighed above is put into a ball mill and wet mixed for 15 hours. Next, in the drying step 3, the slurry obtained by the above-mentioned wet mixing is put in a dryer and dried at 100 ° C. for 20 hours. Next, in the crushing step 4, the dried product of the slurry obtained in the above-mentioned drying step 3 is crushed. Next, in the calcination step 5, the powder of the dried slurry product obtained in the pulverization step 4 is calcinated. This calcination is performed in a firing furnace at 1000 ° C. for 5 hours in an oxygen atmosphere. Next, in the crushing step 6, the solid-state ceramics after the calcination obtained in the calcination step 5 are crushed. Then 2
In the next mixing step 7, the powder obtained in the above-mentioned pulverizing step 6 is secondarily mixed to adjust the powder particle size. Next, in the drying step 8, the powder obtained in the above-mentioned secondary mixing step 7 is dried. Next, in the granulation step 9, 10% of PVA10% aqueous solution as a molding binder is added to the powder after calcination obtained in the above-mentioned drying step 8, and the powder is classified with a # 28 sieve, and this is granulated powder. And Next, in the molding step 10, the granulated powder obtained in the above-mentioned granulation step 9 is subjected to water content adjustment, and pressure molding is performed at a pressing pressure of 8.2 MPa and a pressing time of 200 seconds. Finally, in the firing step 11, the molded body obtained in the above-mentioned molding step 10 is put into a firing furnace, and 1200 to 13
It is fired in an oxygen atmosphere at a temperature in the range of 00 ° C. for 5 hours to obtain a porcelain composition (fired ceramics).

Next, the Q value and the relative permittivity ε of the porcelain composition obtained by the above manufacturing process were measured. The measurement method and the result will be described below. First, the porcelain composition was processed into a cylindrical shape, and the Q value and the resonance frequency f were measured by the both-ends short-circuit method. Here, the measurement frequency is 3.5-
The range was 3.8 GHz.

The result of the Q value measured by the above method is shown in FIG.
And as shown in Table 1.

[0013]

[Table 1]

As can be seen in FIG. 1 and Table 1, the composition of the porcelain composition is ((MgO) _1-x (TiO ₂ ) _x )
_1-Y (MnO) When expressed as _Y , the range of X is 0.1 ≦ X
≦ 0.6 and the range of Y was 0.0 ≦ Y ≦ 0.04, and the Q value was measured. As a result, when X = 0.2, Y =
When the value is 0.0, the Q value is 21000, while the value Y is
= 0.002 to 0.01, Q value is 21000 to 2
A value as high as 6000 was obtained. When X = 0.3, the Q value is 27,000 when Y = 0.0, whereas the Q value is 260 when Y = 0.002 to 0.01.
A high value of 00 to 31000 was obtained. Also, X = 0.
In the case of 4, when the Y value was 0.0, the Q value was 29000, whereas when the Y value was 0.002 to 0.01, the Q value was 29000 to 43000, which was a very high value. . Similar results were confirmed in the range of X = 0.5 to 0.55. Further, when X is in the range of 0.3 ≦ X ≦ 0.55 and Y is in the range of 0.002 ≦ Y ≦ 0.007, the Q value is 28000-52000, which is a particularly high value. . Furthermore, X = 0.5 and Y =
When the value was 0.005, the Q value was 52000, and excellent characteristics could be obtained.

From the above results, the following can be said about the range of X and Y. First, the value of X is 0.2 ≦ X
It is desirable that the range is ≦ 0.55, and further,
The range of 0.3 ≦ X ≦ 0.55 is more desirable. Here, the reason why the value of X is not set to X <0.2 is that the Q value becomes too low in this range and cannot be practically used. Further, the reason why the value of X is not set to 0.55 <X is that the Q value becomes too low in this range and cannot be put to practical use, for the same reason as described above. On the other hand, the value of Y is 0.002 ≦
The range of Y ≦ 0.01 is desirable, and the range of 0.002 ≦ Y ≦ 0.007 is more desirable. Here, the value of Y is not set to Y <0.002 because the effect of MnO addition is small in this range. The reason why the value of Y is not 0.01 <Y is that the Q value is lowered in this range, which is not preferable.

Table 2 shows the results of measuring the relative permittivity ε of the porcelain composition.

[0017]

[Table 2]

As can be seen from Table 2, since the value of the relative permittivity ε is in the range of 10 to 17, even when this porcelain composition is used as an electronic device, it is sufficient to make the electronic device compact. .

From the above, the porcelain composition according to this example has a higher Q value than the conventional material to which MnO is not added. That is, the porcelain composition of this example can obtain a high Q value in the microwave region, and by using this porcelain composition, a dielectric element having low loss and excellent high frequency characteristics can be obtained.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0021]

As described above, according to the present invention,
A porcelain composition having a high Q value can be obtained as compared with a conventional material to which MnO is not added. That is, the high frequency dielectric ceramic composition of the present invention has a high Q in the microwave region.
By using this porcelain composition, it is possible to obtain a dielectric element having low loss and excellent high frequency characteristics.

[Brief description of drawings]

FIG. 1 is a graph showing the effect of adding MnO on the Q value.

FIG. 2 is a process chart for manufacturing a porcelain composition.

Claims (2)

[Claims] 1. The general formula ((MgO) _1-X (Ti
O ₂ ) _X ) _1-Y (MnO) _Y , the value of X is in the range of 0.2 ≦ X ≦ 0.55, and the value of Y is 0.002 ≦ Y ≦ 0.01. A dielectric porcelain composition for high frequency, characterized by having a range. 2. The value of X is in the range of 0.3 ≦ X ≦ 0.55, and the value of Y is in the range of 0.002 ≦ Y ≦ 0.007. Item 1. A high-frequency dielectric ceramic composition according to item 1.