JP3006188B2 - High frequency dielectric ceramic composition - Google Patents

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, and more particularly, to a dielectric ceramic used for a dielectric resonator or a MIC dielectric substrate in a high frequency region such as a microwave or a millimeter wave. The present invention relates to a high frequency dielectric ceramic composition that can be obtained.

[0002]

2. Description of the Related Art Conventionally, as a high frequency dielectric porcelain composition, for example, as disclosed in Japanese Patent Publication No. 2-60628, Ba [(Zn _x Mg ₁ -x) _1/3 (Nb _Y T
a _1-Y ) _2/3 ] O ₃ , where 0 ≦ X ≦ 0.9
5, in the range of 0 ≦ Y ≦ 0.4, Vanadium oxide is V
There was a composition containing 0.05 to ₂ mol% in terms of ₂ O ₅ .

Further, Japanese Patent Application Laid-Open No. Sho 60-124305 discloses
As disclosed, Ba (Sn _XMg_YTa_Z) O
_{7 / 2-X / 2-3Y / 2}(However, X + Y + Z = 1)
0.04 ≦ X ≦ 0.26, 0.23 ≦ Y ≦ 0.3
1, there is a composition in the range of 0.51 ≦ Z ≦ 0.65.
Was.

[0004] These high frequency dielectric ceramic compositions have a large relative permittivity and a high Q value in a high frequency range,
This is a dielectric ceramic material having a good temperature coefficient of resonance frequency.

[0005]

However, recently, the frequency range to be used has been further increased, and at the same time, the demand for miniaturization of communication devices and the like has been increasing. Accordingly, there is a demand for a material having a higher Q value and a higher relative dielectric constant. In addition, the above conventional materials require a high temperature of about 1600 ° C. for sintering,
It was disadvantageous from the viewpoint of energy saving.

Therefore, a main object of the present invention is to provide a dielectric ceramic having an excellent temperature coefficient in a high frequency region, a higher Q value and a large relative permittivity, and which can be fired at a lower temperature. Another object of the present invention is to provide a high frequency dielectric ceramic composition.

[0007]

According to the present invention, the general formula is represented by B
_{a X Sn Y Zr Z Zn U} Ni V Mg K Nb L Ta M O W
(However, X + Y + Z + U + V + K + L + M = 1, W is arbitrary), X, Y, Z, U, V, K, L, M
Are 0.491 ≦ X ≦ 0.504, 0 ≦ Y ≦ 0.
102, 0 ≦ Z ≦ 0.075, 0.021 ≦ U ≦ 0.1
56, 0 ≦ V ≦ 0.050, 0 ≦ K ≦ 0.127, 0 ≦
L ≦ 0.071, 0.220 ≦ M ≦ 0.329 (where Y and Z are not 0 at the same time, and Y, Z, V, K,
Wherein three or more of L are not simultaneously 0).

Here, in the above general formula, part or all of Ni may be replaced with Co, and part or all of Nb may be replaced with Sb.

Further, Ca may be added in the range of 0 to 3 mol%.

[0010]

According to the present invention, a higher Q value can be obtained in a microwave band, a large relative dielectric constant, a good temperature coefficient of resonance frequency, and 1 to 20 GHz.
Thus, a dielectric ceramic composition for high frequency can be obtained, which can be used for a wide range of dielectric ceramics. In addition, the composition according to the present invention can obtain excellent dielectric properties at a lower temperature than conventional compositions, reduce the burden on an electric furnace and the like, and have a large energy saving effect.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments.

[0012]

EXAMPLE First, high-purity BaCO ₃ , S
nO ₂ , ZrO ₂ , ZnO, NiO, MgCO ₃ , Nb
₂ O ₅ , Ta ₂ O ₅ , CoCO ₃ , Sb ₂ O ₃ and C
aCO ₃ was prepared. These raw materials are shown in Tables 1, 2 and 3.
Then, the mixture was weighed so that the composition shown in Table 4 was obtained, and wet-mixed with a ball mill for 16 hours to obtain a mixture. After drying this mixture, it was calcined at 1300 ° C. for 3 hours to obtain a calcined product. This calcined product was put into a ball mill together with water and an organic binder and wet-pulverized for 4 hours to obtain a pulverized product. After drying this pulverized material, it is granulated through a 50-mesh net,
The obtained powder was crushed at a pressure of 2000 kg / cm ^{2 to} a diameter of 12 kg / cm ^2.
It was molded into a disk having a thickness of 5 mm and a thickness of 5 mm to obtain a molded product. This molded product was fired at 1450 to 1650 ° C. for 4 to 10 hours to obtain each sample.

With respect to the obtained sample, a frequency of 10 GHz
, The relative dielectric constant εr, the Q value, and the temperature characteristic τ _f (ppm / ° C.) of the resonance frequency were measured. The measurement results are shown in Tables 1, 2, 3 and 4. In the table, samples with an asterisk (*) are out of the scope of the present invention, and the others are within the scope of the present invention.

[0014]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

Next, according to the present invention, Ba _X Sn _Y Zr
_Z Zn _U Ni _V Mg _K Nb _L Ta _{M OW} (However, X +
The reason for limiting the range of the composition represented by Y + Z + U + V + K + L + M = 1, W is arbitrary) will be described based on Tables 1, 2, 3 and 4.

(1) As shown in sample number 5, X is 0.49
When it is smaller than 1, the Q value becomes small, which is not preferable. If X is larger than 0.504 as in sample No. 1, sintering becomes unstable, which is not preferable.

(2) As shown in sample number 11, Y is 0.1
If it is larger than 02, the relative permittivity εr becomes small, which is not preferable.

(3) As shown in sample number 13, Z is 0.0
If it is larger than 75, the temperature characteristic τ _f of the resonance frequency becomes unfavorably large on the positive side.

(4) As shown in sample number 14, U is 0.0
If it is smaller than 21, the relative permittivity εr becomes small, which is not preferable. Further, as shown in sample number 21, U is 0.1
If it is larger than 56, the Q value becomes small, which is not preferable.

(5) As shown in sample number 22, V is 0.0
If it is larger than 50, the relative permittivity εr becomes small, which is not preferable.

(6) As shown in sample number 14, K is 0.1
If it is larger than 27, the relative permittivity εr becomes small, which is not preferable.

(7) As shown in sample number 25, L is 0.0
If it is larger than 71, the temperature characteristic τ _f of the resonance frequency is undesirably large on the positive side.

(8) As shown in sample number 27, M is 0.2
If it is smaller than 20, the temperature characteristic τ _f of the resonance frequency becomes undesirably large on the positive side. Further, when M is larger than 0.329 as in sample No. 26, the Q value becomes small, which is not preferable.

On the other hand, according to the present invention, it has a large relative dielectric constant and a high Q value in the microwave band, and
A high frequency dielectric porcelain composition that can obtain a high frequency dielectric porcelain that can be used in a wide range up to the GHz band is obtained. Moreover, from the dielectric ceramic composition for high frequencies according to the present invention, it is possible to obtain a dielectric ceramic having good temperature characteristics of the resonance frequency.

Table 2 shows the dielectric properties of the samples fired under various conditions.

(9) X, Y,
Z, U, V, K, L, and M are in the above composition range.
When V and L are both 0 at the same time, the sintering temperature of 1600 ° C. has excellent dielectric properties, but the sintering temperature of 1550 ° C. is not preferable because the Q value becomes small.

(10) As shown in sample No. 31, U is equal to 0.
021, K is larger than 0.127, U, V
When L and L are both 0 at the same time, the sintering temperature of 1600 ° C has excellent dielectric properties, but the sintering temperature of 1550 ° C undesirably results in a small Q value.

(11) As shown in sample No. 32, U is equal to 0.
021, K is larger than 0.127, and Y,
When Z, U and V are simultaneously 0, the calcination temperature of 1600 ° C. or lower undesirably reduces the Q value.

(12) As shown in sample number 33, Y is equal to 0.
Greater than 102, L is greater than 0.071, M is less than 0.220, and Z, V, K and M are simultaneously 0
In the case of (1), the material has a large relative dielectric constant εr even at a sintering temperature of 1500 ° C. or less, and the temperature characteristic τ _f of the resonance frequency is good, but the Q value is undesirably small.

(13) As shown in sample number 34, U is equal to 0.
021, K is larger than 0.127, and Y,
When Z, U and M are simultaneously 0, the relative dielectric constant εr is undesirably small.

On the other hand, as shown in Sample No. 28 and Sample No. 29, the high frequency dielectric ceramic composition according to the present invention has a large relative dielectric constant even in a wide temperature range of 1650 ° C. to 1500 ° C. It is possible to obtain a high frequency dielectric ceramic having a high Q value and a good resonance frequency temperature characteristic τ _f .

Table 3 shows the dielectric properties of samples of the high frequency dielectric ceramic composition according to the present invention in which Ni and Nb were replaced by Co and Sb, respectively.

(14) Sample No. 35 and Sample No. 36
In the case where part or all of Ni is replaced with Co, as described above, the sintering temperature has a large relative dielectric constant and a high Q value even in a wide temperature range of 1600 ° C. to 1500 ° C. The temperature characteristics τ _f are good.

(15) Sample No. 37 and Sample No. 38
When a part or all of Nb is replaced with Sb as described above, even when the sintering temperature is as wide as 1600 ° C. to 1500 ° C., it has a large relative dielectric constant and a high Q value, and further has a resonance frequency. The temperature characteristics τ _f are good.

(16) Sample No. 39 and Sample No. 40
When part or all of Ni is replaced with Co and part or all of Nb is replaced with Sb as in the above, a large relative dielectric constant and a high dielectric constant are obtained even in a wide temperature range of 1600 ° C. to 1500 ° C. And the temperature characteristic τ _{f of the} resonance frequency is good.

Table 4 shows the dielectric properties of the samples to which Ca was added.

(17) If the amount of Ca added is more than 3 mol% as in sample No. 43, the temperature characteristic τ _f of the resonance frequency becomes undesirably large on the positive side.

On the other hand, as shown in Sample No. 41 and Sample No. 42, the high frequency dielectric ceramic composition according to the present invention has a large relative dielectric constant even in a wide temperature range of 1600 ° C. to 1500 ° C. It is possible to obtain a high frequency dielectric ceramic having a high Q value and a good resonance frequency temperature characteristic τ _f .

Continuation of the front page (56) References JP-A-62-222065 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 35/00

Claims (3)

(57) [Claims] The method according to claim 1 of the general formula _{Ba X Sn Y Zr Z Zn U} Ni
_V Mg _K Nb _L Ta _{M OW} (However, X + Y + Z + U +
V + K + L + M = 1, W is arbitrary), X,
Y, Z, U, V, K, L, M are each 0.491 ≦ X
≤0.504, 0≤Y≤0.102, 0≤Z≤0.07
5, 0.021 ≦ U ≦ 0.156, 0 ≦ V ≦ 0.05
0, 0 ≦ K ≦ 0.127, 0 ≦ L ≦ 0.071, 0.2
20 ≦ M ≦ 0.329 (However, if Y and Z are
And three or more of Y, Z, V, K, and L are not simultaneously 0). 2. A method according to claim 1, wherein a part or all of Ni in the general formula is C.
o, and part or all of Nb was replaced with Sb.
The dielectric ceramic composition for high frequencies according to claim 1. 3. The high frequency dielectric ceramic composition according to claim 1, further comprising 0 to 3 mol% of Ca.