JPS61253710A - Dielectric ceramic composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dielectric ceramic composition for a dielectric resonator having a resonance frequency of 10-odd Gtlz.

[Conventional technology]

No-load Q of a dielectric resonator with a resonant frequency of 10-odd GHz
An excellent one is about 10,000. The dielectric of this conventional dielectric resonator contains Ba.[ZnhTah)2
A dielectric ceramic composition represented by the composition formula: /3.(Znl, -INbh)s.03 was used.

[Problem that the invention seeks to solve]

The conventional dielectric ceramic compositions described above were expensive. The reason for this is that the firing temperature in the manufacturing process is as high as approximately 1,600°C, which increases the equipment cost of the firing furnace, its repair cost, and the cost of thermal energy, which increases the manufacturing cost. There is a need for dielectric ceramic compositions that can be fired at low temperatures.

This invention was devised based on the above-mentioned demand, and provides a dielectric ceramic composition that is cheaper than conventional compositions.

[Means to solve the problem]

The dielectric ceramic composition of the present invention that achieves the above objects is
BaH(Mg(x)Co(1-x))Vz
・(Ta <x> Nb (1-X)) s・0
The main component is a composite perovskite in which X in the composition formula represented by 3 is in the range of 0.3 to 0.9, and with respect to 100 parts by weight of the composite perovskite, Al2O3. Cr2O31 Y2O31Mn2o
It contains 0.01 to 0.5 parts by weight of one or more components of group 3.

〔Example〕

Next, Ba in which the value of X in the above compositional formula is 0.5
°(Mgo, s COo, 5) l/3° (T a
o, sN bo, s) 2/3・03 component is 10
A method for producing a dielectric ceramic composition comprising 0 parts by weight and o and ii parts of Cr2O3 will be described.

First, 98.67g of F3aCO3 powder (0,500
MgO powder 3.36 g (0,083 mole equivalent), Coo powder 6.22 g (0,083 mole equivalent).

36.18 g (equivalent to 0,083 mol) of Ta2O5 powder.

22.06 g of Nb2O5 powder (equivalent to 0,083 mol) and 0.167 g of Cr2O3 powder (the above BaCO
0.3 to 100 parts by weight of the total amount of components from Nb2Os to Nb2Os. (equivalent to IM parts) were weighed.

Put this weighed powder into a ball mill with pure water.

Wet mixing was carried out for 24 hours.

The mixture thus obtained was dehydrated and dried at a temperature of 150°C for 5 hours, and then calcined at a temperature of 1100°C for 2 hours. Next, the calcined product was ground in a ball mill. 3.0 g of polyvinyl alcohol was added to the pulverized product, mixed with a soaker, and granulated by passing through a 60-mesh sieve. Put 0.66 g of these granules into a mold,
A pressure of 3 ton/ci was applied. By repeating this pressure molding, a diameter of 7.0*mmφ and a thickness of 3.0mm is obtained.
We made 20 5m discs. Next, divide these disks into 1
Baked at a temperature of 370℃ for 4 hours, diameter approximately 6.0W
A dielectric ceramic disk having a thickness of about 3.1 fl was obtained.

Lap and polish both sides of these dielectric porcelain discs.

Thickness L is 3. Sample 17 was selected as OOm.

Next, 25 of the dielectric resonator using the sample 17 as a dielectric.
The test method and results for measuring the dielectric constant ε at a temperature of °C and the Q without load will be explained.

First, after measuring the diameter of the sample 17 mentioned above with a micrometer,
The relative permittivity ε and the no-load Q were measured using a measurement system consisting of an OA sweep oscillator, an 8410A network analyzer, an 8743A test unit, and a computer.

The above test unit includes two metal end plates (diameter 24 mm, thickness 3 mm) for the electrodes of the dielectric resonator. First, the sample 3 is sandwiched between these metal end plates, and the dielectric resonance occurs. The vessel is constructed. Next, the resonant wave number fo and the insertion loss dB at resonance of this resonator are measured. Then, by inputting the measured value of the insertion loss dB at the time of resonance and the diameter and thickness t of the sample 17, which were actually measured in advance, into a computer, the dielectric constant ε of the dielectric resonator under test and the unloaded Each Q is calculated and the result is printed out.

The relative dielectric constant ε determined in the above measurement system is: according to the computer program.

πD, resonance wavelength λo=C/fo, propagation wavelength λg=2t,
Bessel function of the second kind v2 = (πD/λ0) [(7072
g) 2-1), the Bessel function of the first kind u2 is measured or calculated, and from these values ε=(λo/πD)2 (u2
+v2)+1. In addition, the no-load Q is determined by the load QL according to the computer program.
=fO/f2-fl (power width at half maximum), a.

= 10-IL, /2O is calculated, and from these values, it is calculated using the arithmetic expression Q=QL/1-at.

The relative dielectric constant ε of the 2O samples determined as described above
The average value is 29.8. The maximum value is 29.5. The minimum value is 30
．． It was 2. Also, the average value of Q of 20 samples without load is 12O00. The maximum value is 13600. The minimum value is 112O
It was 0. These average values are shown in the sample number 17 column of the table below, along with the value of X in the above compositional formula and the firing temperature FT.

Furthermore, samples 1 to 16 other than sample number 17 in the table below
For dielectric ceramic compositions Nos. 18 to 24, dielectric resonators were made in the same manner as Sample 17 described above, except that the firing temperature FT was slightly different depending on each composition, and the same method as above was used. The characteristics of each resonator were determined using the method. The average values of these properties and the firing temperature FT are shown in the table below.

As is clear from the above results, the dielectric ceramic composition according to the present invention had a firing temperature FT of 1350 to 1400°C. Furthermore, the dielectric constant ε of a dielectric resonator using these dielectric ceramic compositions is as follows.

25.0 to 32.6, and the unloaded Q is 102
It was O0-122O0.

In addition, in the measurement system mentioned above, one of the dielectric resonators 2
When the temperature coefficient of the resonant frequency in the temperature range of 5 to 100°C was determined, all samples were found to be in the range of 0±6 ppn+/°C.

Composition formula Ba ・(Mg (X) Co (1-X) )
L/3' (Ta (x) Nb (1-X >
)Me・03, the dielectric ceramic composition in which X is less than 0.3 has an unloaded Q of 10000 in the dielectric resonator.
Since this result does not satisfy the premise of this invention, it is excluded from the scope of this invention. Furthermore, in a dielectric ceramic composition in which I left it outside.

Furthermore, Al2O3, Cr2O3, Y2O3.

The added amount of the component containing one or more of the Mn2O3 group is based on the above compositional formula Ba.(Mg(X)C).

(1-X>)so(Ta<x)Nb(1-
X>) X in Gong-03 is less than 0.01 parts by weight per 100 parts by weight of the component in the range of 0.3 to 0.9.

Since it is not effective in lowering the firing temperature FT of the dielectric ceramic composition, it is excluded from the scope of the present invention. On the other hand, if the amount of this component added exceeds 0.5 parts by weight, the unloaded Q will be 10,000.
Since the premise of this invention cannot be satisfied, it is also outside the scope of this invention.

〔Effect of the invention〕

As explained above, the dielectric ceramic composition of the present invention can obtain properties equivalent to those of conventional compositions, and can lower the firing temperature FT during the manufacturing process to 1370 to 1400°C. A dielectric ceramic composition that is cheaper than conventional dielectric ceramic compositions can be obtained in terms of equipment such as a firing furnace and thermal energy for firing. Specifically, a cost reduction of about 15% is expected compared to conventional dielectric ceramic compositions that require a firing temperature FT of 1600° C. for sintering.

Claims (1)

[Claims] Ba・[Mg_(_x_)Co_(_1_-_x)]
_1_/_3・[Ta_(_x_)Nb_(_1_-_
x_)]_2_/_3・O_3 100 parts by weight of the component whose compositional formula x is in the range of 0.3 to 0.9, and A
l_2O_3, Cr_2O_3, Y_2O_3, Mn_
One or more components of the group 2O_3 are 0.01 to 0.
A dielectric ceramic composition comprising 5 parts by weight.