JPH0642326B2 - Dielectric porcelain composition - Google Patents

Description

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

More specifically, when the present invention is a dielectric resonator used in the microwave frequency band, the unloaded Q (Q _u ) and the relative permittivity (ε _r ) are large, and the temperature coefficient (τ _{f of the} resonance frequency is )
The present invention relates to a dielectric ceramic composition having excellent stability.

[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 no-load Q is large and the stability of the temperature coefficient of the resonance frequency is excellent. At the same time, a material with a large relative permittivity is generally desirable, but if the relative permittivity is too large, the resonator becomes too small and difficult to handle. Therefore, it is required depending on the frequency band in which the resonator is used. The value of the relative permittivity also differs.

As a ceramic composition conventionally used for a resonator as a dielectric resonator material, Ba (Mg1 / 3Ta2 / 3) O ₃ system (Japanese Patent Publication No. 59-23) is used.
048), Ba (Zn1 / 3Ta2 / 3) O ₃ system (Japanese Patent Publication No. 59-4).
8484 JP), Ba (Zn1 / 3Nb2 / 3) O 3 system (JP 53-
35453), Ba (Mg1 / 3Nb2 / 3) O ₃ system (JP-A-5353)
-35345), CaTiO ₃ -MgTiO ₃ -La ₂ O ₃ .2TiO
Many have already been proposed, such as the ₂ system and the Sr (Zn1 / 3Nb2 / 3) O ₃ —SrTiO ₃ system.

[Problems to be solved by the invention]

However, the conventional porcelain composition is used in the microwave frequency band because the unloaded Q is small, the dielectric constant is so small that the shape of the resonator is considerably large, and the temperature coefficient is large. One of the problems with the resonator material is that it is inconvenient in actual use.

An object of the present invention is to provide a dielectric ceramic composition suitable as a dielectric resonator material, particularly a dielectric resonator material used in a microwave (including millimeter wave) frequency band.

Another object of the present invention is to provide a dielectric porcelain composition having a high stability with no load Q and a large relative permittivity and a temperature coefficient of resonance frequency of ± 30 ppm / ° C or less, preferably ± 10 ppm / ° C or less. To provide.

[Means and Actions for Solving Problems]

The object of the present invention is achieved by a porcelain composition in which a part or all of Zn in the Ba (Zn1 / 3Nb2 / 3) O ₃ system is replaced with Ni, and a part of Nb is replaced with Sb.

The present invention, barium, nickel, zinc, niobium, composition formula consisting of antimony and oxygen, Ba _{[(Ni 1-x Zn x)} 1/3 (Nb 1-y Sb y) 2/3 ] 0 ₃ (wherein , 0 ≦ x <1, preferably 0.1 ≦ x ≦ 0.7,
0 <y ≦ 0.2, preferably 0.001 ≦ y ≦ 0.1)
The present invention relates to a dielectric ceramic composition represented by

In the composition of the present invention, nickel has a large effect on improving the temperature coefficient of resonance frequency. Further, antimony has a great effect on the improvement of temperature characteristics and the improvement of no load.

It should be noted that the dielectric ceramic composition containing no nickel or antimony has a big 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 carbonates and oxides of barium, nickel, zinc, niobium, antimony, etc. are mixed and calcined, followed by molding and firing to sinter. can do.

For example, a predetermined amount of barium carbonate, nickel oxide, zinc oxide, niobium pentoxide and antimony trioxide is wet mixed with a solvent such as water or alcohol. Then, after removing water, alcohol, etc., it is pulverized, and is crushed under an oxygen-containing gas atmosphere (for example, an air atmosphere) at 800 to 1400 ° C.
Calcination for about an hour. The calcined material thus formed is crushed, then mixed with an organic binder such as polyvinyl alcohol to be homogenized, dried, crushed and pressure-molded (pressure 100 to 3000 kg / cm ² ). Then, this molded product is exposed to an oxygen-containing gas atmosphere such as air at 1300 to 1600 ° C.
The dielectric ceramic composition of the present invention can be obtained by firing at.

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

〔Example〕

Example 1 Barium carbonate [Ba (O ₃ )] powder 1 mol, nickel oxide (Ni
O) powder 0.2056 mol, zinc oxide (ZnO) powder 0.1
277 mol, niobium oxide (Nb ₂ O ₅ ) powder 0.3317 mol and antimony trioxide (Sb ₂ O ₃ ) powder 0.0017
Moles were placed in a ball mill 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 was calcined at 1300 ° C. in an air atmosphere, and then crushed again by a mashing machine for 1 hour. This pulverized product was mixed with an appropriate amount of a polyvinyl alcohol solution and uniformly mixed, and then formed into a disk-shaped pellet having a diameter of 15 mmφ and a thickness of 7 mm, which was fired and sintered at 1470 ° C. for 4 hours in an air atmosphere, and then sintered in this example. A dielectric porcelain composition of was obtained.

The porcelain composition thus obtained had a diameter of 11 mmφ and a thickness of 4 ·
After cutting to a size of 3 mm, it was measured by the dielectric resonance method, and unloaded Q at resonance frequency _o (4.5 to 5.5 GHz).
And the relative permittivity ε _r was obtained. The temperature dependence of the resonance frequency was measured in the range of -40 to 50 ° C to obtain the temperature coefficient τ _f . The results are shown in Table 1.

Examples 2 to 12 Similar to Example 1, except that the amounts of nickel oxide, zinc oxide, niobium oxide, and antimony trioxide used in Example 1 were changed and the firing temperature was changed, the composition formula, Ba [(Ni _{1- x} Z
n _{x) 1/3,} (in Nb _1-y Sb _{y) 2/3]} 0 _3, the values of x and y to produce a dielectric ceramic composition as set forth in Table 1, Example 1
The electrical characteristics were measured in the same manner as in.

The results are shown in Table 1.

Comparative Example 1 The composition formula, Ba [(Ni _0.3 Zn _0.7 ) 1/3 · (Nb _0.7 S, was changed by changing the amounts of nickel oxide and antimony trioxide used in Example 1.
Although an attempt was made to obtain a dielectric ceramic composition represented by b _0.3 ) 2/3] O ₃ which is outside the scope of the present invention, sintering did not proceed sufficiently.

Comparative Example 2 A dielectric ceramic composition [(Ba (Zn1 / 3Nb2 / 3)] was obtained in the same manner as in Example 1 except that the nickel oxide and antimony trioxide of Example 1 were not used and the firing temperature was 1530 ° C. O ₃ ] was manufactured and the electrical characteristics were measured in the same manner as in Example 1.

As a result, Q = 11000, ε _r = 38.8, τ _f = 36 ppm / ° C.

EFFECTS OF THE INVENTION The dielectric ceramic composition of the present invention has not only a large unloaded Q, but also an appropriately large relative permittivity, a small temperature coefficient of resonance frequency, and excellent stability. It is suitable as a body resonator material.

Further, when the dielectric ceramic composition of the present invention is used as a resonator for a microwave frequency band, for example, the performance of the receiver can be greatly improved and the size can be reduced.

Claims (1)

[Claims] 1. A barium, nickel, zinc, niobium, composition formula consisting of antimony and _{oxygen, Ba [(Ni 1-x} Zn x) 1/3 (Nb 1-y Sb y) 2/3] 0 3 ( wherein In the formula, 0 ≦ x <1, 0 <y ≦ 0.2).