JPH0845347A - Dielectric porcelain composition for high frequency - Google Patents

Abstract

PURPOSE:To provide a dielectric porcelain composition for use at high frequencies, which has a higher Q value in high frequency ranges than before, shortens baking time and has good productivity. CONSTITUTION:BaCO3, ZnO, CO3O4, Nb2O5, MnO, Cub, Al2O3, Y2O3, and CeO2 are prepared as raw materials, which are blended into a composition represented by the general formula Ba {(CoxZn1-x)yNb1-y}zOw omega (omega is a certain number, 0<(x)<1,0.313<=(y)0.333, and 0.993<=(z)<1). To this porcelain composition, at least one kind selected from MnO, Cub, Al2O3 and Y2O3 is added for a total of 0.5wt.%, or less (not including 0wt.%), or CeO2 is added for a total of 0.-5wt.% or less (not including 0wt.%).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency dielectric ceramic composition.

[0002]

2. Description of the Related Art Conventionally, dielectric ceramics have been widely used for dielectric resonators, dielectric substrates for MICs, etc. in a high frequency range such as microwaves and millimeter waves. In this case, it is preferable that the Q value is large, the stability of the temperature coefficient (τf) of the resonance frequency is excellent, and the relative dielectric constant is large.

Conventionally, Ba (Co _X Ta _y Nb _z ) O _{7 / 2-3x / 2} system (Japanese Patent Publication _No.
-56404), Ba (Zr _x Zn _y Ni _z Ta _u N
b _v ) O _{7 / 2-x / 2-3y / 2-3z / 2} system (Japanese Patent Publication No. 5-48563), TiO ₂ —ZrO ₂ —SnO ₂ system (Japanese Patent Publication 4-5)
9267), Ba (Co _1/3 Nb _2/3 ) O ₃ -Ba
(Zn _1/3 Nb _2/3 ) O ₃ system (Japanese Patent Publication No. 4-321), (1-x) Ba (Co _1/3 Nb _2/3 ) O ₃ -xBa
(Zn _1/3 Nb _2/3 ) O ₃ system (JP-A-62-252008)
A number of proposals have been already proposed.

For example, Ba (Co _1/3 Nb _2/3 ) O ₃ --Ba (Zn _1/3 N) disclosed in Japanese Patent Publication No. 4-321.
The b _2/3 ) O ₃ system is fired at 1350 ° C. to 1500 ° C. for 2 to 40 hours to obtain a dielectric ceramic composition having a Q value of 6500 at a microwave band of 6.5 GHz.

Further, (1-x) Ba (Co _1/3 Nb _2/3 ) O ₃ disclosed in JP-A-62-252008 is disclosed.
The -xBa (Zn _1/3 Nb _2/3 ) O ₃ system is fired in the air and then heat-treated at 1250 to 1400 ° C. in an inert gas atmosphere to give a microwave band of 6.5 GHz at 64 GHz.
A dielectric ceramic composition having a Q value of 00 to 14000 is obtained.

[0006]

However, recently, the frequency range to be used has become higher, and in response to this, a material having a higher Q value is required. In the conventional porcelain composition, a high Q value cannot always be obtained, and in order to increase the Q value, Japanese Patent Publication No. 4-321 discloses firing for a long time (usually about 20 to 40 hours), and JP In Japanese Patent Laid-Open No. 62-252008, after firing in the atmosphere, heat treatment is further performed in an inert gas atmosphere. Under such firing conditions, the firing time is long and the heat treatment atmosphere is carried out in an inert gas atmosphere, and the firing costs are high, which is a major obstacle to improving productivity and reducing costs. It was

An object of the present invention is to provide a dielectric ceramic composition for high frequency, which has a high Q value in the high frequency region as compared with the conventional one, and has a short firing time and high productivity.

[0008]

The invention according to claim 1 is
In the general formula _{Ba {(Co x Zn 1-} x) y Nb 1-y} z Oω ( although, omega is an arbitrary number) ceramic composition represented by,
x, y, and z are 0 <x <1, 0.313 ≦ y <, respectively.
The dielectric ceramic composition for high frequencies is in the range of 0.333 and 0.993 ≦ z <1.

According to a second aspect of the present invention, the porcelain composition is a main component, and at least one of yttrium oxide, aluminum oxide, manganese oxide and copper oxide is added to the Y composition.
It is a dielectric ceramic composition for a high frequency in which the total amount thereof is 0.5% by weight or less (excluding 0% by weight) in terms of ₂ O ₃ , Al ₂ O ₃ , MnO, and CuO.

According to a third aspect of the present invention, the porcelain composition is contained as a main component, and 0.5% by weight or less (however, not including 0% by weight) of cerium oxide converted into CeO ₂ is added thereto. A high frequency dielectric ceramic composition.

According to a fourth aspect of the invention, the porcelain composition is the main component, and at least one of yttrium oxide, aluminum oxide, manganese oxide, and copper oxide is added to the Y composition.
Converted to ₂ O ₃ , Al ₂ O ₃ , MnO, and CuO, the total amount of 0.5 wt% or less (however, not including 0 wt%) was added, and cerium oxide was converted to CeO _2. 0.5 wt% or less (however, 0 wt% is not included) is added to the high frequency dielectric ceramic composition.

The invention according to claim 5 relates to the general formula Ba {(C
_{o x Zn 1-x) y} Nb 1-y} z Oω ( although, omega in ceramic composition represented by any number), x, y, z is 0.5 ≦ x ≦ 0.9, respectively, 0.313 ≦ y <0.33
3, the main component is in the range of 0.993 ≦ z <1, and at least one type of manganese oxide and copper oxide is converted into MnO and CuO, each of which is 0.1 wt% or less (however, It is a dielectric ceramic composition for a high frequency, which is added (not including 0% by weight) and is further added by 0.5% by weight or less (however, not including 0% by weight) in terms of CeO ₂ in terms of CeO ₂ .

The reason for limiting the composition range of the claims is as follows. In the complex perovskite structure represented by the general formula A (B′B ″) O ₃ , (B ′
B ") atoms are partially deleted from the equivalent, or (B'B")
When there is a large amount of deficiency of B'atom, there is a great effect in improving the Q value. Porcelain composition Ba {(Co _x Z
When n _1-x ) _y Nb _1-y } _z Oω is applied to the general formula A (B′B ″) O ₃ , A is Ba, B ′ is (Co _x Zn _1-x ) _y ,
B ″ becomes Nb _1-y .

That is, if the value of x of the (Co _x Zn _1-x ) component is x = 0 or x = 1, no sintering occurs or Q
The value becomes low. Further, when the y value of (Co _x Zn _1-x ) _y Nb _1-y is y <0.313 or y ≧ 0.333, the temperature of the resonance frequency does not change because sintering is not performed or the Q value is extremely low. The coefficient cannot be measured. Furthermore, {(Co _x Zn _1-x ) _y
The value of z of Nb _1-y } _z is z <0.993 or z ≧ 1.
Then the Q value becomes low.

Next, yttrium oxide, aluminum oxide, manganese oxide, and copper oxide are added to Y ₂ O ₃ , Al ₂ O ₃ , and Mn.
If the total amount of O and CuO exceeds 0.5% by weight, the Q value becomes low. Furthermore, cerium oxide was added to Ce.
If converted to O ₂ and exceeds 0.5% by weight, the Q value becomes low.

[0016]

According to the present invention, the general formula Ba {(Co _x Zn
_1-x ) _y Nb _1-y } _z Oω (where ω is an arbitrary number), 0 <x <1, 0.313 ≦ y <0.
333, a porcelain composition having a composition represented by 0.993 ≦ z <1 has a relative permittivity of 30 or more, a temperature coefficient of resonance frequency in the range of −10 to +30 ppm / ° C., and a Q value of It is 10,000 or more. In addition, at least one kind of yttrium oxide, aluminum oxide,
By adding manganese oxide, copper oxide, or cerium oxide, the Q value is increased without changing the relative permittivity and the temperature coefficient of the resonance frequency.

[0017]

EXAMPLES The present invention will be described below with reference to examples. As raw materials, BaCO ₃ , ZnO, Co ₃ O ₄ , Nb ₂ O ₅ ,
MnO, CuO, Al ₂ O ₃ , Y ₂ O ₃ , and CeO ₂ were prepared, compounded in the composition ratios shown in Table 1, and the compounded raw materials were wet mixed for 16 hours using a ball mill, followed by dehydration,
It is dried, calcined at 1100 to 1300 ° C. for 3 hours, a binder is added to the calcined powder, and a ball mill is used for 16 hours,
The adjusted powder was obtained by wet-grinding again. In addition, M
nO may be manganese carbonate.

[0018]

[Table 1]

Then, the adjusted powder was press-molded at a pressure of 2000 kg / cm ² so as to form a disk having a dimension of 12 mm in diameter and 6 mm in thickness after firing, and the disc was heated at 1420 to 1520 ° C. for 4 hours.
It was fired for a time to obtain a sintered body.

Using the obtained dielectric ceramic sample, the relative dielectric constant (εr) at the resonance frequency (7.2 to 7.6 GHz),
The Q value and the temperature coefficient (τf) of the resonance frequency were examined.
The relative permittivity and Q value are measured by a dielectric resonance method with both ends short-circuited. The temperature coefficient of the resonance frequency indicates the temperature change rate of the resonance frequency, and the measurement range is + 25 ° C to +
It is measured in the temperature range of 80 ° C. The measurement results are shown in Table 2.

[0021]

[Table 2]

In Tables 1 and 2, the sample numbers marked with * are outside the scope of the present invention, and the others are within the scope of the present invention.

From these results, the high frequency dielectric ceramic composition according to the present invention has a Q value of 100 to 100 at a range of 7.2 to 7.6 GHz.
It is as high as 00 or more, the relative dielectric constant is 30 or more, and the temperature coefficient of the resonance frequency is in the range of -10 to 30 ppm / ° C.

In particular, the range of x is set to 0.5 ≦ x ≦ 0.9, and at least one manganese oxide or copper oxide is added to Mn.
O and CuO are added in an amount of 0.1 wt% or less (however, 0 wt% is not included), and cerium oxide is converted to CeO ₂ in an amount of 0.5 wt% or less (however, 0 wt%). The porcelain composition added has a Q value of 12,000 or more.

Further, yttrium oxide, aluminum oxide, manganese oxide, and copper oxide are related to the firing time. Without addition, a high Q value is required unless the firing top temperature is maintained for a long time (usually about 20 to 40 hours). I can't get it,
When added within the claimed range, a high Q value can be obtained at a firing top temperature for a short time (about 4 hours). Further, cerium oxide can adjust the Q value and the temperature coefficient of the resonance frequency to desired values without changing the relative dielectric constant.

[0026]

According to the present invention, it is possible to obtain a high-frequency dielectric porcelain having a high Q value and a good temperature coefficient of resonance frequency without changing the relative permittivity. In addition, the Q value in the microwave band exceeds 10,000, which is 1 to 10 GH
It is possible to use from z to higher 10 to 50 GHz band. In particular, when the range of x is 0.5 ≦ x ≦ 0.9, at least one kind of MnO and CuO is added by 0.1 wt% or less (however, 0 wt% is not included), and further CeO _{2 is} added.
Is added in an amount of 0.5% by weight or less (however, 0% by weight is not included), the Q value becomes 12000 or more, and a dielectric ceramic composition for high frequencies applicable to a higher frequency region can be obtained.

Moreover, in the prior art, a high Q value could not be obtained unless the firing top temperature was maintained for a relatively long time, but according to the present invention, a high Q value can be exhibited even if firing is performed for a short time. As a result, the firing time can be greatly shortened and the productivity can be improved.

Claims (5)

[Claims] 1. The general formula Ba {(Co _x Zn _1-x ) _y N
In the porcelain composition represented by b _1-y } _z Oω (where ω is an arbitrary number), x, y, and z are 0 <x <1, respectively.
A high frequency dielectric porcelain composition, which is in a range of 0.313 ≦ y <0.333 and 0.993 ≦ z <1. 2. The porcelain composition as a main component, to which at least one type of yttrium oxide, aluminum oxide, manganese oxide, and copper oxide is added Y ₂ O ₃ , Al ₂ O ₃ , Mn.
The high-frequency dielectric ceramic composition according to claim 1, wherein the total amount of O and CuO added is 0.5 wt% or less (not including 0 wt%). 3. The porcelain composition as a main component, to which cerium oxide is added in an amount of 0.5 wt% or less (not including 0 wt%) in terms of CeO _2. The high frequency dielectric ceramic composition according to claim 1 or 2. 4. The porcelain composition as a main component, to which at least one type of yttrium oxide, aluminum oxide, manganese oxide, and copper oxide is added Y ₂ O ₃ , Al ₂ O ₃ , Mn.
O and CuO are added in a total amount of 0.5 wt% or less (excluding 0 wt%), and cerium oxide is converted to CeO ₂ in an amount of 0.5 wt% or less (but The dielectric ceramic composition for high frequencies according to claim 1, wherein the dielectric ceramic composition for high frequency is added. 5. The general formula Ba {(Co _x Zn _1-x ) _y N
In the porcelain composition represented by b _1-y } _z Oω (where ω is an arbitrary number), x, y, and z are each 0.5 ≦ x ≦
0.9, 0.313 ≦ y <0.333, 0.993 ≦ z
The main component is in the range of <1 and at least one type of manganese oxide and copper oxide is converted into MnO and CuO, and each is 0.1% by weight or less (however, 0% by weight).
Is added), and cerium oxide is added to CeO ₂
0.5% by weight or less (excluding 0% by weight) is added to the dielectric ceramic composition for high frequency.