JPS61142601A - Dielectric ceramic composition for high frequency - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a high frequency dielectric ceramic composition having a higher Q value than conventional ones in the high frequency range such as microwaves and millimeter waves.

<Prior Art> In high frequency regions such as microwaves and millimeter waves, dielectric ceramics are widely used for dielectric resonators, dielectric substrates for MIC, and the like.

Conventionally, as this type of dielectric porcelain, for example, 7, r
02- Sn Ot-D LO2-based material, Ba, TLqO
x* (0 gutter, Sr), (Zr, TL) Os-based material,
Ba (Zn, Ta) Os-based materials and the like are known.

However, these various materials all have a frequency of 10GH2
1,: Dielectric constant (ε): 20 to 40, Q: 400
0 to 8000, temperature coefficient (τf) of co-pregnancy frequency is Opp
It is also known to be an excellent material with properties of m7°C.

<Problems to be Solved by the Invention> However, recently, the frequency range used has become even higher, and correspondingly, materials having an even higher Q value are required.

Means for Solving the Problems> In view of the above points, the present inventors have conducted extensive research and found that it has a high dielectric constant in the high frequency region, a high Q value, and a temperature coefficient of Oppm 7 at the co-photography frequency. We have discovered a dielectric ceramic composition for high frequencies that can obtain any value centered around °C.

That is, the gist of this invention is that Ba Co 3
, Co, CO3, Ta 20J-, r 20r, and the general formula 8% is 0.2≦x≦0.45, O≦y≦0.80.0≦, respectively.
The dielectric ceramic composition for high frequency is within the range of l≦0.80 (where x+y+z=i>).

<Action> Here Ba (Co%TayNbL) Q+1-1y,
In the composition of X.

The reason why y and z are limited to the above-mentioned ranges will be explained.

In other words, the reason why X is set in the range of 0.2 to 0.45 is that X is 0.
．． This is because if it is less than 2 or exceeds 0.45, Q will decrease, and y is set to θ~0.80 because if it exceeds 0.80, sintering becomes difficult.

Furthermore, the reason why 2 is set in the range of 0 to 0.80 is because if it exceeds 0.80, Q decreases.

<Example> This invention will be explained below with reference to Examples.

High purity Ba cos, CALCOJ, Ta as raw materials
Using 2O-1IV & 1I20re, the weighed raw materials were mixed part-time for 2 hours by hanging on a scale so as to obtain porcelain having the composition ratio shown in Table 1.

Next, this mixture was calcined at 1200° C. for 2 hours, a binder was added, and the mixture was mixed again in sections for 2 hours, followed by dehydration and granulation.

The obtained powder was heated to 12mmφX6 at a pressure of 2000r4.
It was molded into a disk having dimensions of mmj.

Furthermore, this disk was fired at 1450° C. for 4 hours to obtain 1 q of porcelain samples.

Regarding the thus obtained ceramic sample, the dielectric constant (ε) and Q at a frequency of 70H2 were measured using the dielectric resonator method,
Further, the temperature coefficient (τf) of the resonant frequency was calculated from the temperature change rate of the resonant frequency in the temperature range from +25°C to +85°C. The results are shown in Table 1.

Items marked with * in Table 1 are outside the scope of the claims of this invention.

The drawings also show Ba (Co) among the compositions according to the present invention.
The composition ranges of x, y, and z of xTa, Nb, ) 0y-sy are shown, and the numbers in the figure match the sample numbers in Table 1.

Table 1 In the above table, sample numbers 9 to 11 are It cannot be put to practical use.

On the other hand, the material according to the present invention exhibited a high dielectric constant and a good temperature coefficient (τf) of the resonance frequency, and in particular, showed a maximum Q value of 9,600.

Therefore, the dielectric ceramic composition of the present invention exhibiting such characteristics is useful for applications such as dielectric resonators and dielectric substrates for MIC.

[Brief explanation of the drawing]

The drawings are from Ba ((5) Tay Takashi,) O of this invention.
15/, shows the composition range of x, y, and z in the composition.

Claims (1)

[Claims] General formula, Ba(Co_xTa_yNb_z)O_7_/
In the composition represented by _2_−_3_x_/_2,
x, y, and z are respectively 0.2≦x≦0.45, 0≦y≦0.
80, a dielectric ceramic composition for high frequency use, characterized in that it is in the range of 0≦z≦0.80 (however, x+y+z=1).