JPH063683B2 - Dielectric porcelain composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dielectric magnetic composition containing barium, zinc, (niobium), antimony and oxygen, which is suitable as a dielectric resonator material.

More specifically, the present invention has a large unloaded Q (Qu) when used as a dielectric resonator used in the microwave frequency band, and the relative permittivity (ε _r ) and the temperature coefficient of the resonance frequency are determined according to the application.
The present invention relates to a dielectric ceramic composition in which (τ _f ) can be arbitrarily controlled in a wide range.

[Conventional technology]

The size of the dielectric resonator is generally Inversely proportional to, the larger the relative permittivity, the smaller the resonator and the circuit can be made. Therefore, as a ceramic composition of the resonator material, the unloaded Q is large and the stability of the temperature coefficient of the resonance frequency is excellent. At the same time, it is generally desirable to have a large relative electric permittivity, but if the relative permittivity is too large, the resonator will not be too small and will be difficult to handle. Therefore, it may be required depending on the frequency band in which the resonator is used. The value of the relative permittivity also varies.

A magnetic composition conventionally used for a resonator as a dielectric resonator material is Ba (Mg _1/3 Ta _2/3 ) O ₃ system (Japanese Patent Publication No. 59-23).
048), Ba (Zn _1/3 Ta _2/3 ) O ₃ system (Japanese Patent Publication No. 59-4).
8484), Ba (Zn _1/3 Nb _2/3 ) O ₃ system (JP-A-53-
35453), Ba (Mg _1/3 Nd _2/3 ) O ₃ system (JP-A-5353)
-35345 _{discloses), CaTiO 3 -MgTiO 3 -La 2} O 3 · 2tiO
Many have already been proposed such as the ₂ system, the Sr (Zn _1/3 Nd _2/3 ) O ₃ —SrTiO ₃ system.

[Problems to be solved by the invention]

However, conventionally known porcelain compositions such as Ba (Zn _1/3
Single porcelain compositions such as Nd _2/3 ) O ₃ and Ba (Zn _1/3 Ta _2/3 ) O _{3 have} their own specific dielectric constant and temperature coefficient of resonance frequency, and can be controlled arbitrarily. Because I cannot do it,
As a resonator material used in the microwave frequency band, there are many practical disadvantages.

An object of the present invention is to provide a dielectric ceramic composition having a large unloaded Q and capable of arbitrarily controlling the relative permittivity and the temperature coefficient of the resonance frequency in a wide range.

[Means and Actions for Solving Problems]

The object of the present invention is to prevent the Ba (Zn _1/3
This is achieved by a magnetic composition in which a part or all of Nb _2/3 ) O ₃ Nb is replaced with antimony.

The present invention includes a formula consisting of barium, zinc, niobium, antimony and oxygen, Ba [Zn _1/3 (Nb _1-X Sbx) _2/3 ] O ₃ (wherein 0 <x ≦ 1, preferably 0.001 <x ≦ The present invention relates to a dielectric ceramic composition represented by 1).

In the composition of the present invention, antimony has a function of arbitrarily controlling the relative dielectric constant and the temperature coefficient of the resonance frequency and also has a great effect on the improvement of the Q value.

The composition containing no antimony, namely Ba (Zn
_1/3 (Zn _1/3 Nb _2/3 ) O ₃ has a drawback that the temperature coefficient of the resonance frequency is too large.

The dielectric porcelain composition according to the present invention is manufactured by a method in which starting materials such as carbon salts and oxides of barium, zinc, niobium, antimony, etc. are mixed and calcined, followed by molding and firing to sinter. You can

For example, barium carbonate, zinc oxide, niobium pentoxide, and antimony trioxide are removed from water, alcohol, and the like in predetermined amounts, and then pulverized, and the mixture is crushed in an oxygen-containing gas atmosphere (eg, air atmosphere) at 800 to 1400 ° C. for about 10 hours. Calcination about. The calcined material formed by this is crushed, then mixed with an organic binder such as polyvinyl alcohol to be homogenized, dried, crushed and pressure-molded (pressure 100 to 300).
0 kg / cm ² ). Then, the dielectric ceramic composition of the present invention can be obtained by firing this molded product at 1300 to 1600 ° C. in an oxygen-containing gas atmosphere such as air.

The dielectric ceramic composition thus obtained becomes a dielectric resonator when it is processed as it is or into an appropriate shape and size as required. Further, the dielectric ceramic composition of the present invention can be used as a material for a dielectric substrate for microwave IC, a dielectric adjusting rod, and the like.

Example 1 Barium carbonate (BaCO ₃ ) powder 0.6 mol, zinc oxide (ZnO)
0.2 mol of powder, 0.198 mol of niobium oxide (Nb ₂ O ₅ ) powder and 0.02 mol of antimony trioxide (Sb ₂ O ₃ ) powder were put in a ball mill together with ethanol and wet-mixed for 16 hours. The mixture was taken out of the ball mill, the solvent ethanol was evaporated, and the mixture was pulverized with a muller for 2 hours. The crushed product is calcined in an air atmosphere at 1300 ° C and then re-crushed with a crusher.
Crushed for hours. This pulverized product was mixed with an appropriate amount of polyvinyl alcohol solution and uniformly mixed, and then molded into a disk-shaped pellet having a diameter of 15 mmφ and a thickness of 7 mm, which was then subjected to 153 in an air atmosphere.
The dielectric ceramic composition of the present invention was obtained by firing and sintering at 0 ° C. for 4 hours.

The porcelain composition thus obtained had a diameter of 11 mm and a thickness of 4.3 m.
After cutting to a size of m, measurement was performed by the dielectric resonance method, and the unloaded Q and the relative permittivity ε _r at the resonance frequency f _o (4.5 to 5.5 GHz) were obtained. Regarding the temperature dependence of the resonance frequency, the temperature coefficient τ _f measured in the range of −40 to 50 ° C. was obtained. The results are shown in Table 1.

Examples 2 to 5 The values in the formula Ba [Zn _1/3 (Nb _1-X Sbx) _2/3 ] O ₃ were changed from those in Table 1 by changing the amounts of niobium pentoxide and antimony trioxide used in Example 1. A dielectric porcelain composition was produced and its electrical characteristics were measured in the same manner as in Example 1.

However, only the porcelain composition described in Example 5 had a diameter of 7 mmφ,
Resonance frequency (f _o ) after cutting into a disc with a thickness of 4.3 mm
The electrical characteristics at 10 to 11 GHz were measured.

The results are shown in Table 1.

Comparative Example 1 The firing temperature was adjusted to 15 without using the antimony oxide of Example 1.
A dielectric ceramic composition [(Ba (Zn _1/3 (Nb _1/3 Nb _2/3 ) O ₃ ]) was produced in the same manner as in Example 1 except that the temperature was 30 ° C.
The electrical characteristics were measured in the same manner as in.

As a result, Q = 1000, ε _r = 38.8, τ _f = 36 ppm
/ ° C.

[Advantages of the Invention] The dielectric ceramic composition of the present invention has not only a large unloaded Q, but also can control the relative permittivity and the temperature coefficient of the resonance frequency as desired, so that it can be used as a dielectric resonator material for each frequency band. It is suitable.

Further, when the dielectric ceramic composition of the present invention is used, for example, as a resonator for microwave frequency band, there is an advantage that the performance of the receiver can be greatly improved.

Claims (1)

[Claims] 1. A dielectric material represented by the formula Ba [Zn _1/3 (Nb _1-X Sbx) _2/3 ] O ₃ (where 0 <x ≦ 1) consisting of barium, zinc, niobium, antimony and oxygen. Porcelain composition.