JPS59196502A - 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 Field of Industrial Application The present invention is applicable to barium oxide (Bad), titanium oxide (TlO
2) + This relates to a high-frequency dielectric ceramic composition composed of samarium oxide (Sm205) and tin oxide (Sn02), which has a large relative permittivity (εr) and exhibits dielectric resonance in the microwave frequency band. To provide dielectric porcelain having a large no-load Q (Qu) when used as a device, having a stable temperature coefficient (τf) of a resonance frequency, and capable of changing the temperature coefficient over a wide range depending on the application. There is a particular thing.

Configuration and problems of conventional examples In recent years, the wavelength has been on the enemy's side, and the following microwaves and millimeter waves (hereinafter referred to as
With the advancement of high-frequency circuit technology that handles microwaves (collectively referred to as microwaves), efforts are being made to miniaturize these circuits. In this technology, cavity resonators, antennas, etc. have been used in this high-frequency circuit, but the size of these devices is comparable to the wavelength of microwaves, which has been an obstacle to miniaturization. To solve this,
A method has been used to shorten the wavelength itself by using dielectric ceramics with a high dielectric constant.

TiO2-based materials are often used as materials suitable for such uses; for example, Ti02-ZrO2-8n0
2 yarns, CaTiO3-MgTiO3-La2O3-
2TiO2 series, recently Ba (ZnATa, 3)
Dielectric ceramics such as 03-Ba (Zn, Nb, )3, -4.03 thread are known. However, when a dielectric resonator is made of these materials, the relative dielectric constant is as low as about 30, so the resonant frequency is, for example, about 1.
When a 1GITz X-band dielectric resonator is used with a material with ε1=30, it becomes a small unit with a diameter of 5.6u1 and a thickness of 2.2cm, but the frequency decreases to a U of about 2GHz.
When used in the HF band, the shape becomes significantly larger with a diameter of 30.7 mm and a thickness of about 12.3 s when the same εr-3o material is used. If the dielectric constant of the material used here could be increased to about 80, the size could be reduced to 18.8 mm in diameter and 7.6 mm in thickness, but conventional materials could not meet these requirements. could not be satisfied.

Purpose of the Invention The present invention has been made in order to improve the above-mentioned drawbacks, and has improved the relative dielectric constant and no-load Q, and has a stable temperature coefficient of the resonance frequency, and can change this temperature coefficient depending on the application. The aim is to provide dielectric ceramics that can be varied over a wide range.

Structure of the Invention The present invention provides x BaO-y Ti02-z Sm2O3
In the composition represented by 6≦X≦23 (Mo/l/%
).

57≦y≦82.5 (molar ratio), 2.5≦2≦37.5
(mol%), X + y + z - 100 (mo/I/ti) is the main component, and SnO2 is added to the main component in the range of 5 weight percent or less (however, excluding 0 weight %), and it is an excellent porcelain. This is a dielectric porcelain for high frequency use.

Description of Examples The starting logs contain chemically highly purified BaCO2, TiO2.
.

Sm2O3 and 5n02 were weighed to have a predetermined composition and wet mixed with pure water in a rubber-lined ball mill equipped with an agate ball. After each mixture was taken out from the ball mill and dried, it was calcined in air at a temperature of 900° C. for 2 hours. The calcined product was ball milled with pure water as described above. After dehydrating and drying the crushed slurry, 5 liters of powder
--- The grains were sized through a 32-mesh sieve. The sized powder was molded into a disk with a diameter of 2011 mm and a thickness of about 8 words using a mold and a hydraulic press at a molding pressure of 80 degrees KV 2 m. The molded bodies were placed in high-purity alumina pots and fired in air at a temperature within the range of 1220 to 1650°C for 2 hours, depending on the composition, to obtain dielectric porcelain with the composition shown in the table. .

Using this ceramic element, the resonant frequency, no-load Q, and relative dielectric constant were determined from measurements using the dielectric resonator method. The temperature dependence of the resonance frequency was measured in the range of -30°C to 70°C, and the temperature coefficient τf was determined. The resonant frequency was 2-4 GHz. The experimental results obtained are shown in the table. Note that the samples marked with * in the table are comparative examples outside the scope of the present invention, and the other samples are examples within the scope of the present invention.

As is clear from the table below, the dielectric ceramic within the scope of the present invention can increase the no-load Q while maintaining a high relative dielectric constant. In addition, since the dielectric ceramic of the present invention exhibits stable temperature characteristics of the resonant frequency, it is useful for stabilizing the temperature dependence of oscillators and resonators. Suitable for use in applications, it is possible to create small, high-performance electronic circuit components.

To explain the reason for limiting the range of the main component composition, BaO
The amount (X) is 23 mo) more than V, or Ti
02fi (7) is less than 57 mo/I/ section, S
If the amount of m2O3 (Z) is less than 2.5 molti, it will be difficult to sinter the porcelain, and the no-load Q will decrease, making it impossible to measure, so it is excluded from the scope of the present invention. Also,
X is less than 5 mo/I/% or 2 is 37
If y exceeds 82.6 mofi/%, the sintering of the porcelain becomes unstable and the no-load Q decreases, making it impossible to measure.However, if y exceeds 82.6 mofi/%, If the sintering of the porcelain becomes unstable and the temperature characteristics change significantly, it is excluded from the scope of the present invention.

Regarding the amount of 5n02 added as a subcomponent, as the amount added increases, the sintering temperature of porcelain can be lowered, the no-load Q can be increased, and the temperature characteristics can be changed. If it is added in an amount larger than 5% by weight, the dielectric constant and the no-load Q will be significantly lowered, and therefore it is excluded from the scope of the present invention.

Effects of the Invention The dielectric ceramic composition of the present invention has a large dielectric constant in the microwave frequency band, a large no-load Q, and a stable temperature coefficient of the resonant frequency, so that the temperature of the oscillator, resonator, etc. Useful for stabilizing dependencies. It is still suitable for use in the UHF band due to its large dielectric constant.
It is possible to create small, high-performance electronic circuit components. Furthermore, the temperature coefficient of the desired resonance frequency can be selected by changing the composition of the material, so when the dielectric resonator is assembled, a temperature compensation effect that eliminates the influence of the surrounding metal plates on the temperature characteristics can be achieved. Mota 9 Be: j It can be done. Further, the dielectric ceramic composition of the present invention can provide a material useful not only for dielectric resonators but also for microwave substrates, dielectric adjustment rods, etc.
It is widely used for industrial purposes.

Name of agent: Patent attorney Toshi Nakao Haga 1 person 9-

Claims (1)

[Claims] A dielectric porcelain made of barium oxide, titanium oxide, samarium oxide, and tin oxide, its main component composition is xBao-
When expressed as yTi02-zsm203, x, y
, z is 5≦X≦23 (mol%), 57≦y≦82.
5 (molti), 2.5≦2≦37.5 (mol%), X+
A dielectric ceramic composition characterized in that 5n02 is added in an amount of 6% by weight or less (excluding 0% by weight) based on the main component in the range of 7+Z=100 (molti).