JPS61127661A - Dielectric ceramic material - 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 [Field of Application of the Invention] The present invention relates to a dielectric ceramic material used for dielectric resonators and the like.

[Background of the invention]

The sieve casing material is suitable for high frequencies, especially in the microwave region.
It is being applied to impedance matching devices and dielectric resonators, and is becoming increasingly popular due to its advantages such as the temperature coefficient of the resonant frequency close to O and the miniaturization of components due to low loss and high dielectric constant.

Conventional sieve materials used for these dielectric resonators include (a) TiO, -BaO-ZnO system Ba (Zn
1/a'Ta 2/a)Os-Ba(Znl/
3.Nb2/3) 03 system Ti02-Zr01- SnO, system Φ) CaTi0. - MgTi0. -La, 03・
2 TiO, system (c) Tie, -BaO-Nd,
0. systems have been proposed. However, although the material (a) has a small temperature coefficient of resonance frequency, it also has a small St ratio. On the contrary, the material Φ) has a large dielectric constant, but also has the disadvantage of a large temperature coefficient of resonance frequency.

Generally, there is a relationship between the dielectric constant of a material and the temperature coefficient of the resonant frequency, such that as the dielectric constant increases, the temperature coefficient of the resonant frequency also increases, and materials with a large dielectric constant and a small temperature coefficient of the resonant frequency are There weren't many. The material (C) is superior to the materials (a) and (b) in that it has a larger dielectric constant and a smaller temperature coefficient of resonance frequency, but the temperature coefficient of the resonance frequency is +80 ppm.
/'C rank, still unsatisfactory.

[Purpose of the invention]

The purpose of the present invention is to eliminate such drawbacks of the prior art,
While simultaneously satisfying high U-electricity and stable temperature characteristics,
5. To provide a porcelain sieve material with low tolerance.

[Mosquito Woman of Invention]

In order to achieve the above object, the present invention uses titanium oxide, barium oxide and neodymium oxide as components, and has a compositional formula of xTiO in terms of the total oxides of these components.

-yBaO-zNd, 0. The component ratio x when expressed as
y.

A composition in which y of 2 is 11.9 to 16.6-1-% and 2 is 10.0 to 10.0%, OmoA/% (however, x + y
+z is 100 mol%) 10h is iron oxide F'
e, 0. It is characterized in that the content is in the range of 1 to 1 O1 in terms of .

〔Example〕

The present inventor has developed high-purity Ti as a starting material for electromagnetic ceramic materials.
e, ,BaC0,,Nd,0. and Fe, 03 were weighed so as to have a predetermined composition as described below, and wet-mixed with pure water using a resin ball mill equipped with an agate ball.

After dehydrating and drying the mixture, place it in the air at 1,200°C.
It was calcined for 3 hours at a temperature of After this calcined product was wet-pulverized in the ball mill and dried, 2 parts by weight of polyvinyl alcohol as a binder and water were added and mixed, and the mixture was granulated using a granulator.

Next, this granulated product was dry pressed at a pressure of 1,500 Kf/i and formed into a disk with a diameter of 7 mm and a thickness of about 5 mm.

This molded body was placed in an alumina sheath pot and fired in air for 3 hours at a temperature range of 1,250 to 1,500°C depending on the composition to obtain each sample.

〔Effect of the invention〕

Each sample was manufactured using the dielectric resonator method with a resonance frequency of V8 to 10GH.
2, the dielectric constant (tr), dielectric loss (tan δ), and temperature coefficient of resonance frequency (τf) were measured, and the results are shown in the following table.

Note that the measurement temperature of τf ranges from -40°C to 70°C.

The parts by weight of Fe2O3 in the table indicate the proportion to 100 parts by weight of the main composition.

As is clear from this table, the composition formula of the main composition is 8% and 2 is 10.0 to 20.0. If the dielectric loss (tan δ) or temperature coefficient (τ
f) increases.

On the other hand, if the addition ratio of B'e, 03 is less than 1 part by weight, the temperature coefficient (τf) will be large, and if it exceeds 10 parts by weight, the dielectric loss (
tan δ) increases.

On the other hand, the compositional formula of the main composition xT i 02・yBa
In O・zNd, 03, y of component ratio XS yl z
is 11.9~15, 6% k, %, 2 is 10.0~
20.0'-+! LI% and this main composition Zo
1 to 101 parts of Fe2O was added to the oz position (sample numbers 2.3.5.6.8 to 13.1.5.
16) has a high dielectric constant (45 or more) and a stable temperature coefficient (
It is a dielectric ceramic material with a small dielectric loss (tan δ19 x 10 or less) while simultaneously satisfying τf -4-56 ppm/'C or less.

Claims (1)

[Claims] Titanium oxide, barium oxide, and neodymium oxide are the components, and these components are converted into oxides and the composition formula is xTiO_
A composition in which y is 11.9 to 16.6 mol% and z is 10.0 to 20.0 mol% of the component ratios x, y, and z when expressed as 2.yBaO.zNd_2O_3 (however, x
+y+z=100 mol%) A dielectric ceramic material containing iron oxide in an amount of 1 to 10 parts by weight in terms of Fe_2O_3.