JPS61142602A - 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 high Q value in a 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 0
2- Sn 02 TL Os-based material, Ba OTL
Os-based materials, (Ba, Sr) (Zr, Th)
Os-based materials, Ba (ZTI, Ta) 03-based materials, and the like are known.

However, these various materials all have a frequency of 10G.
At HZ, dielectric constant (ε) is 20 to 40, Q is 300
0 to 6000, temperature coefficient of resonance frequency (τ') is 01)
E) It is also known to be an excellent material with properties around III/'C.

<Problems to be Solved by the Invention> Recently, however, the high 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 made extensive studies and found that a material that has a high dielectric constant in the high frequency region and a high Q value,
We have discovered a high-frequency dielectric ceramic composition that can obtain an arbitrary value for the temperature coefficient of resonance frequency around 01) l) m/°C.

That is, the gist of this invention is that [3aO1Sn
01.1% O, Ta 20t, which is surrounded by the general formula 9, and 70 atomic % or less of - is substituted with NL or/and, and at least one lanthanide rare earth element is added to this. An object of the present invention is to provide a high frequency dielectric ceramic composition containing 10 mol % or less of .

<Function> The drawings are based on the Ba (5nyXyTaj
It is a graph which shows the range of x, y, and z in the composition of o%-%-'g.

Here, the reason why x, y, and z in the above composition are limited to the above ranges will be explained.

In other words, the reason for setting x in the range of 0.04 to 0.26 is that
．． If it is less than 0.04 or more than 0.26, the Q will decrease.The reason for setting ■ to 0.23 to 0.31 is that if it is less than 0.23, the Q will decrease and the temperature of the resonance frequency will decrease. This is because the coefficient @(τf) becomes too large in the positive direction, and if it exceeds 0.31, sintering becomes difficult. Further, when l is set in the range of 0.51 to 0.65,
This is because if it is less than 0.51, sintering will be difficult or Q will decrease, and if it exceeds 0.65, Q will decrease.

Also, replacing 1 in Ba (S+Ja, Taz) 0%-%-3 with Ni or/and Ni moves the temperature coefficient (τf) of the resonance frequency to the negative side, and at that time changes the amount of substitution appropriately. The purpose is to control τf and obtain a porcelain useful for temperature compensation, but the reason why - is substituted with NL or/and 6 is 70 atomic % or less.
This is because if the amount exceeds that amount, the Q value decreases.

Furthermore, the addition of lanthanide rare earth elements (R) to oxides (
The reason why the amount is set to 10 mol % or less in terms of R,0,) is that if this amount is exceeded, the Q value decreases.

Example of implementation Hereinafter, this invention will be explained in detail with reference to Examples.

High purity +7) Ba COj, Sn Ot as raw materials
, r1kICO4, Ta 20ANi O, Co
Using 20J or an oxide of a lanthanide rare earth element, weigh it so as to obtain porcelain having the composition ratio shown in Table 1, put this mixed raw material into a rubber-lined ball mill with water, and wet mix for 2 hours. did.

Next, this mixture was dehydrated and dried, and then heated to 1200°C.
The calcined product was placed in a ball mill together with water and an organic binder and wet-pulverized for 2 hours.

Thereafter, this pulverized product was dried and granulated through a 50-mesh mesh, and the obtained powder was molded into a disk having dimensions of 10 mmφ x 5 mm t under a pressure of 20,001 q J.

Furthermore, this disk was fired at 1500° C. for 4 hours to obtain a porcelain sample.

For the porcelain sample thus obtained, a frequency of 10GH2
The dielectric constant (ε) and Q were measured using the dielectric resonator method, and the temperature coefficient (τt) 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.

In the above table, sample numbers 41 to 58 are Ba (Sn, i
, TaJ)0-1. -g-)% any value of x, y, z is outside the scope of this invention,
It is difficult to sinter or the properties have deteriorated.

Sample numbers 1.2.8.13.19.24.30 and 35 are examples in which no U]/tanide rare earth element is added and are excluded from the scope of the present invention.

Also sample number 5.7.12.16.18.23.27.
29.34.38 and 40 are those in which the substitution m of 1 with N and/or exceeds 70 atomic %, or the lanthanide rare earth element R is added in an amount exceeding 10 mol % in terms of R20. Both of these are outside the scope of this invention.

<Effects> As detailed above, according to the present invention, it is possible to obtain a dielectric ceramic composition for high frequencies that has a high dielectric constant and exhibits a high Q value that has not been obtained conventionally.

In particular, by replacing -, the main component, with NL or/and 6, and further adding lanthanide rare earth elements as necessary, the temperature coefficient (τf) of the common imaging frequency can be reduced while achieving a high Q value. It can be appropriately adjusted mainly in Oppm/°C.

It goes without saying that lanthanide rare earth elements, which are not listed as examples, can have similar effects.

The dielectric ceramic composition of the present invention having the above characteristics can be used for applications such as dielectric resonators, dielectric adjustment rods, and dielectric substrates.

[Brief explanation of the drawing]

The drawings are of this invention.
It is a graph showing the range of x, y, and z in a composition of -%-'%.

Claims (1)

[Claims] BaO, SnO_2, MgO, Ta_2O_5-, general formula Ba(Sn_xMg_yTa_z)O_7_
In the composition represented by /_2_-_x_/_2_-_3_y_/_2, x, y, and z are each 0.04≦x≦0
．． 26, 0.23≦y≦0.31, 0.51≦z≦0.
65 (however, x + y + z = 1), and 70 atomic % or less of Mg is replaced by Ni or/and Co, and in addition, at least one kind of lanthanide rare earth element is converted into an oxide. A dielectric ceramic composition for high frequency use, characterized in that it contains 10 mol% or less of.