JPH05136615A - Dielectric object for micro wave - Google Patents

Abstract

PURPOSE:To obtain an intermediate characteristic value and to arbitrarily and freely perform the fine adjustment of the characteristic value by combining plural dielectric ceramic raw stocks with a different characteristic value and coupling the stocks integrally by the simultaneous sintering. CONSTITUTION:After a raw dielectric ceramic sheet 1 having a temperature coefficient tau f1 of a resonance frequency and a raw dielectric ceramic sheet 2 having a temperature coefficient tau F2 different from the temperature coefficient tau f1 of the resonance frequency of the sheet 1 are mutually superposed, they are coupled integrally by the simultaneous sintering. The obtained sintering substrate is used as the substrate of a micro wave strip line filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic dielectric material used in a microwave region such as a dielectric filter and a dielectric resonator, and more particularly to a ceramic dielectric material having an arbitrary characteristic value. It is about things.

[0002]

2. Description of the Related Art In this type of ceramic dielectric material used in the microwave region, the temperature coefficient τf of the resonance frequency, the dielectric constant ε, the no-load Qu, etc., which are the characteristic values, are designed for microwave electronic equipment. It is an important parameter above, and it is desirable to be able to control such characteristic values arbitrarily and freely. Therefore, conventionally, materials have been developed according to the purpose so that desired compositional values can be obtained by selecting the ratio of the component composition.

[0003]

By the way, the development of a new ceramic dielectric material having an arbitrary characteristic value is costly and time consuming, which increases the manufacturing cost of the device. Therefore, an object of the present invention is to provide a dielectric material for microwaves having a desired characteristic value according to the purpose of use by combining a plurality of dielectric ceramic bodies having different characteristic values.

[0004]

In order to achieve this object, the ceramic dielectric material for microwaves of the present invention has a plurality of dielectric ceramic raw materials laminated with different characteristic values,
It is characterized in that they are integrally joined by simultaneous firing. The different characteristic values of the plurality of dielectric ceramic bodies used in the present invention may be such that at least one of the temperature coefficient τf of the resonance frequency, the dielectric constant ε, and the unloaded Qu is different from each other. The plurality of dielectric ceramic bodies used may have the same thickness or different thicknesses.

[0005]

As is apparent from the experimental examples described later, the characteristic value of the obtained ceramic dielectric material for microwaves is an intermediate value of the characteristic values of the dielectric ceramic elements used. That is, the characteristic value of the microwave ceramic dielectric body obtained by changing the combination or the number of used dielectric ceramic bodies having different known characteristic values or the thickness of each dielectric ceramic body to be used. Can be easily set arbitrarily within the range of the characteristic value of each dielectric ceramic body used.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention, in which a raw dielectric ceramic sheet 1 having a temperature coefficient τf1 of a resonance frequency, and a temperature coefficient τf2 of a resonance frequency different from the temperature coefficient τf1 of the resonance frequency of the dielectric ceramic sheet 1. The raw dielectric ceramic sheets 2 having the above are stacked on top of each other and then co-fired to be integrally joined. These raw ceramic sheets 1 and 2 are
It is manufactured by the doctor blade method or the like. The fired substrate thus obtained can be used as a substrate for a microwave stripline filter.

FIG. 2 shows another embodiment of the present invention, which is a cylindrical block 11 made of a raw dielectric ceramic having a temperature coefficient τf1 of resonance frequency, and a temperature coefficient τf1 of resonance frequency of the columnar block 11. Temperature coefficient τf2 at different resonance frequencies
Block made of raw dielectric ceramic with
12 and 12 are laminated and integrally joined by simultaneous firing. These green ceramic blocks are manufactured by press molding. The fired substrate thus obtained can be used as a microwave dielectric resonator.

In each of the above constructions, the raw ceramic sheets 1 and 2 or the blocks 11 and 12 may have different dielectric constants or may have different unloaded Qus. Further, in each of the above-mentioned configurations, the required number of layers of the raw ceramic sheets or blocks may be the required number of layers having different characteristic values. Furthermore, in the embodiment illustrated in FIGS. 1 and 2, the green ceramic sheets 1 and 2 and the blocks 11 and 12 may be used in combination having different thicknesses.

Next, an experimental example for demonstrating the operation of the present invention will be described. First, as a starting material, high purity BaO, T
_{iO 2, NdO 3/2, Y 2} O 3, and using the Al ₂ O _3, these materials BaO (0.15 mol) -TiO ₂ (0.
6 mol) -NdO _3/2 (0.2 mol) + Y ₂ O ₃ (7.5% by weight) were weighed so as to have a composition ratio, dry-primed by a mixer and subjected to primary mixing and mixing.
It was calcined at ℃ for 2 hours. Next, an appropriate amount of organic binder and water are added to this calcined powder, and the mixture is crushed by a ball mill and spray-dried to granulate.
The first ceramic green sheet 1 was formed into a sheet of 75 mm square and 1.0 mm thick. The characteristic values after sintering of this sheet are: τf1 = + 8.3ppm / ° C, ε1 = 80, Qu
1 = 1600. In addition, BaO (0.15 mol) -TiO ₂
(0.6 mol) -NdO _3/2 (0.2 mol) + Y ₂ O ₃ (7.
5% by weight) + Al ₂ O ₃ (1.0% by weight) except that the composition was weighed so that the second ceramic green sheet 2 was produced in the same manner as described above.
The respective characteristic values of the ceramic green sheet 2 after sintering are τf2 = -8.9 ppm / ° C, ε2 = 68, and Qu2 = 1700. The first and second ceramic green sheets 1 and 2 thus obtained were laminated on each other and thermocompression-bonded at 100 ° C. under 390 kg / cm, and then the laminated body was fired at 1330 ° C. in the atmosphere. The results of measuring the respective characteristic values of the dielectric laminate were as follows. Note that τf is the temperature coefficient of the resonance frequency calculated from the temperature change rate of the resonance frequency in the temperature change of -40 to + 85 ° C, and ε and Qu are the resonance frequency of 2.7 GHz and the parallel conductor plate type dielectric resonance method is used. It was measured in the TE ₀₁₁ mode. τf = −2.7 ppm / ° C. ε = 76 Qu = 1670

As shown in the above experimental example, in the temperature coefficient of the resonance frequency with respect to the characteristic value, τf1 <τf <
τf2, the permittivity is ε1 <ε <ε2, and the unloaded Qu is Qu1 <Qu <Qu2.
Thus, a value approximately in the middle of the characteristic values of the two dielectric ceramics used was obtained.

[0011]

As described above, according to the present invention, a plurality of dielectric ceramic green bodies having different characteristic values are combined and integrally joined by simultaneous firing, so that any characteristic value can be obtained as in the prior art. Without having to develop individual materials according to
By simply combining ceramic bodies with known characteristic values, intermediate characteristic values can be obtained, so not only can the manufacturing cost be significantly reduced, but the characteristic values can be adjusted arbitrarily and freely. Therefore, it is possible to easily provide a microwave dielectric material having an optimum characteristic value at a low cost according to the purpose, and therefore, it is possible to extremely easily design a microwave electronic device of this kind. ..
Furthermore, according to the present invention, since a plurality of ceramic bodies are integrally bonded by simultaneous firing, air having a small dielectric constant does not exist between the ceramic bodies, so that the effective dielectric constant is It also has the effect of preventing a decrease in

[Brief description of drawings]

FIG. 1a is a perspective view showing a substrate for a stripline filter according to an embodiment of the present invention. b: A vertical sectional side view of the above embodiment.

FIG. 2a is a perspective view showing a resonant block for a dielectric resonator according to another embodiment of the present invention. b: A vertical sectional side view of the above embodiment.

[Explanation of symbols]

 1: Raw ceramic sheet 2: Raw ceramic sheet 11: Cylindrical block made of raw dielectric ceramic 12: Cylindrical block made of raw dielectric ceramic

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Takase 14-18 Takatsuji-cho, Mizuho-ku, Nagoya-shi, Aichi Nihon Special Ceramics Co., Ltd.

Claims (6)

[Claims] 1. A ceramic dielectric material for microwaves, characterized in that a plurality of dielectric ceramic green bodies having different characteristic values are laminated and integrally joined by simultaneous firing. 2. The ceramic dielectric material for microwaves according to claim 1, wherein the characteristic value is a temperature coefficient τf of a resonance frequency. 3. The ceramic dielectric material for microwaves according to claim 1, wherein the characteristic value is a dielectric constant ε. 4. The ceramic dielectric material for microwaves according to claim 1, wherein the characteristic value is unloaded Qu. 5. The ceramic dielectric material for microwaves according to claim 1, wherein the laminated dielectric ceramic green bodies have the same thickness. 6. The ceramic dielectric material for microwaves according to claim 1, wherein the dielectric ceramic green bodies to be laminated have different thicknesses.