JPS6054900B2 - Dielectric ceramic composition for high frequency - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dielectric ceramic composition for high frequency use.

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, ZrO has been used as this type of dielectric ceramic.

-SnO2-TiO2-based material, Ba2Ti9O2o, (
Ba,Br)(Zr,Ti)O. based materials, Ba(Zn,
Ta)O. Materials such as these are known. These materials have a dielectric constant (Er) of 20 to 40 and a Q of 4 in the microwave band.
000 to 8000, temperature coefficient (Tf) of resonance frequency is 0
Although it is an excellent material with a characteristic of pμm/°C, recently, the frequency range in which it is used has become higher, and a material with an even higher Q value is required. Therefore, it is an object of the present invention to provide a dielectric ceramic composition that has a higher Q in the high frequency region than conventional compositions.

That is, the gist of this invention is that the general formula B
In the composition represented by a(Sn, Zn, Ta2)O, 12-, 10-, 10, 0.02≦X≦0.13, 0
．． It is characterized by being in the range of 28≦y≦0.33, 0.59≦z≦0.65 (however, x+y+z=1).

Hereinafter, this invention will be explained in detail according to examples. High purity BaC0a9SnO and 9ZnO9Ta2O5 were weighed to obtain porcelain having the composition shown in Table 1, and the weighed raw materials were wet mixed for 2 hours.

Next, calcination was performed at 1200° C. for 2 hours, and a binder was added and wet-mixed again for 2 hours, followed by dehydration and sizing. The obtained powder was heated to 2000 to 12wn at a pressure of 9/a1.
φ×6Tfgn was formed into a disk from the dimensions and heated at 1450°C.
, 4 hours to obtain a porcelain sample. Regarding the obtained porcelain sample, the dielectric constants E and Q at a frequency of 7GH2
) and the temperature coefficient Tf of the resonance frequency were measured, and the results are shown in Table 1.

Items marked with * in Table 1 are outside the scope of this invention, and all others are within the scope of this invention. Furthermore, FIG. 1 shows SnO2, ZnO, Ta0 among the compositions according to the present invention.
The composition range of 5I2 is shown, and the sample number in the figure corresponds to sample number I in Table 1.

The temperature coefficient τf of the resonance frequency in Table 1 is a value determined in the temperature range of +25°C to +85°C based on the following equation.

1J＾1bdW艷! Here, τε: Temperature change rate of dielectric constant ε α: Linear expansion coefficient of porcelain sample As is clear from Table 1, the present invention is as follows:
In addition to exhibiting a high dielectric constant, it also has a good τf, and in particular, a maximum Q value of 13,700 has been obtained, making it useful for applications such as dielectric resonators and dielectric substrates for ■C in the high frequency region. Dielectric ceramics for high frequencies can be provided.

It should be noted that samples having compositions outside the scope of the present invention (sample numbers 7 to 9) cannot be sintered or have a large τf, and cannot be put to practical use.

[Brief explanation of the drawing]

FIG. 1 is a ternary diagram showing the composition ranges of SnO2, ZrlO, and TaO5l2 among the compositions according to the present invention.

Claims (1)

[Claims] 1 General formula Ba(Sn_xZn_yTa_z)O_7/
In the composition represented by _2_-_x/_2_-_3_y/_2, 0.02≦x≦0.13, 0.28≦y≦
0.33, 0.59≦z≦0.65 (however, x+y+
A dielectric ceramic composition for high frequency use, characterized in that z is in the range of 1).