JPS5851406A - High frequency dielectric porcelain composition - 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 The present invention relates to a high frequency dielectric ceramic composition having a high dielectric constant and a high Q value of 1.

Recent advances in technology for high-frequency circuits that handle wavelengths of less than 1, ie, microwaves and millimeter waves (hereinafter collectively referred to as microwaves), have led to miniaturization of circuits.

Conventionally, cavity resonators, antennas, etc. have been used in this high-frequency circuit, but these have become an obstacle to rounding and downsizing to the same size as the microwave wavelength. Rounding K solves this problem.

One possible method is to shorten the wavelength itself, but one way to achieve this is to use dielectric ceramics.

As such materials, TlO2-based materials are often used, such as CaTl0. -MtTiO, -La
, O, , -2, TiO, , Ba0-Tie, etc., the resonator is constructed with IQ. However, these materials do not meet the characteristics required when used in microwaves, such as having a high dielectric constant, having a high q value, and having a stable temperature change characteristic of the dielectric constant. Sufficient results were obtained to satisfy all the conditions.

To answer such requests, Tie, -flr
og-8nO, as the product, ZnO, Co, O, or ZnQ.

A material containing NiO was proposed. However, N.P.
O (meaning that the temperature change rate of dielectric constant is ots)
"t" 70HM f) q value at frequency is 6oo
α7000 and only small values were obtained.1
Therefore, it is an object of the present invention to eliminate the above-mentioned nine conventional drawbacks and to provide a dielectric ceramic composition for high frequency use that has MPOK and a high Q value.

Another object of the present invention is to provide a high-frequency dielectric ceramic composition having a high dielectric constant.

Furthermore, by making the composition ratio curved, this invention
The object of the present invention is to provide a dielectric ceramic composition for high frequency use having an arbitrary dielectric constant and temperature change rate, mainly based on NPO.

That is, the gist of this invention is that 'f' 1
0122~45 weight (4, Zr0, 38~58 weight e4
．． The main component is 5nO19-26% by weight, and this [ZnO
It contains up to 7 parts by weight of Ta, O, and up to 5 parts by weight.

The reason for limiting the composition to the above composition range is as follows.

That is, when Tie is less than 22wt, the dielectric constant (ξ)
decreases and exceeds 43% by weight, the temperature coefficient of dielectric constant (T
C) becomes too large on the plus side. t Zr01 is 3
It should not be less than 8% by weight, but for some turtles, if it exceeds 58% by weight, the temperature coefficient (TC) of the dielectric constant is too large on the plus side. Furthermore, when 8nO is less than 9% by weight, the temperature coefficient of permittivity (TC) is on the positive side, and the Q decreases with a large reduction, and when it exceeds 26% by weight, the temperature coefficient of permittivity (TC)
becomes too large on the negative side.

Next, when ZnO among the additives exceeds 7% by weight, the dielectric constant
Q decreases * 17jTa20. If the value exceeds 5wt, Q decreases.41K"tOs has the function of making the crystal growth uniform, so it suppresses the increase in lattice misalignment within the crystal,
As a result, it has the effect of improving Q.

Hereinafter, this invention will be explained in detail according to examples.

High purity Tie, ZrO, 8nO1, as a raw material
ZrxO9τa, Os was weighed to obtain porcelain having the composition ratio shown in Table 1, and mixed for 16 hours. In the next step, dehydrate and dry the resulting mixed raw material at 2500#/d.
It was molded into a disk with a diameter of 12-1 and a thickness of 61 m at a pressure of . Subsequently, the molded product was fired in a natural atmosphere at a temperature of 1560° C. for 3 hours to obtain a porcelain sample.

The electrical properties of the dielectric constant (Q) and temperature coefficient (TC) of the resonant frequency at 25R and 70HH were measured for each porcelain sample, and the results are shown in Table 1.

The seals in Table 1 are outside the scope of this invention.

Everything else is within the scope of this invention.

Also, in Table 1, as reference examples, Tie, -Zr
The main components of Ol-8nO, ZnO, NiO or Z
nO.

The electrical properties were similarly measured and the results are also shown for the materials doped with Co and Os. The dielectric constant <1 in Table 1 and the value of q were measured by the dielectric resonance method. It is something. Further, TC represents the temperature change rate of the resonance frequency (fo), and #J constant was measured in the temperature range of +25C to +85'C.

The temperature change rate of the resonant frequency (fo) [TC(fo)] is calculated from the following formula, and the temperature change rate of the dielectric constant (g) (T
C(t)] and the linear expansion coefficient (ff) of porcelain due to temperature change. TC(fo)=-%TC(@
)-a again. When we measured the crystal grain size and bending strength of sample number 13 and reference example 1, sample number 13 had a crystal grain size of 5 to 10 μm, a bending strength of 1200/d,
The crystal grain size of Reference Example 1 was 10 to 30 μm.

It has a bending strength of 900 KI/d, and by containing Ta1O1, a thick porcelain with a small crystal grain size and a strength of 1 can be obtained.

As is clear from the above embodiments, according to the present invention,
When the temperature coefficient (TC) of the resonant frequency is 0,
Compared to conventionally known compositions, a material with a higher dielectric constant and a larger value of Q can be obtained.

In addition, by changing the composition ratio, ypo is the main
Since the temperature coefficient (TC) of any resonant frequency can be obtained, it is possible to have a temperature compensation effect with other electronic components when incorporated into a high frequency circuit.

Therefore, it is possible to provide a high-frequency dielectric magnetic composition useful for dielectric resonators, antennas, substrates, etc. used in high-frequency regions.

patent applicant Murata Manufacturing Co., Ltd.

Claims (1)

[Claims] Tie, 22-45 wt%-zrOt38-58 wt i1
%, 8nO1? −26Jit* as the main component, j#L
High-frequency dielectric ceramic composition 7 containing Zn*1% by weight or less, Ta, O, added at 5% by weight or less at °C