JP3067919B2 - Low frequency sinterable porcelain composition for high frequency - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature sinterable porcelain composition for constituting a porcelain portion of a high-frequency laminated ceramic capacitor, inductor, resonator or the like.

[0002]

2. Description of the Related Art As a ceramic composition constituting a ceramic material such as a laminated ceramic capacitor, an inductor, and a resonator for high frequency use, for example, BaO-TiO ₂ -Re (where Re is a rare earth element), ZrO ₂ -SnO _2- TiO ₂ system, Ba
(Zn _1/3 Ta _2/3 ) O ₃ composite perovskite is known.

[0003]

Since these compositions have a sintering temperature as high as 1100 to 1600 ° C., when they are used as a dielectric material of a laminated ceramic capacitor, for example, tungsten, molybdenum, palladium is used as an internal electrode. High melting point metal such as must be used. However, since these refractory metals have low electric conductivity, when this laminated ceramic capacitor is used in a high-frequency circuit, there is a problem that the dielectric loss increases and the Q decreases.

The above-mentioned composition has a relative dielectric constant of 20 to
Since it is as high as 100, when it is used as a dielectric material of a laminated ceramic capacitor for high frequency, for example, there is a problem that a self-resonant frequency is generated on a relatively low frequency side, so that the capacitor does not function in a high frequency region.

An object of the present invention is to provide a high-frequency low-temperature sinterable ceramic composition which can produce a high-frequency ceramic composition having a low relative dielectric constant by firing at a relatively low temperature of 900 ° C. or less. And

[0006] Specifically, densely sintered at a temperature calcination of 900 ° C. or less, the dielectric constant epsilon _r of 10 or less, Q is 500 or more, the temperature coefficient τε of the dielectric constant epsilon _r is 0 ± 60 ppm / ° C
It is an object of the present invention to provide a high-frequency low-temperature sinterable porcelain composition capable of forming the above porcelain composition.

[0007]

Means for Solving the Problems The high-frequency low-temperature sinterable porcelain composition according to the present invention is formed by sintering a mixture of a ZrO ₂ powder and a glass powder, and comprises a ZrO ₂ powder (X) and a glass powder ( The molar ratio of Y) is 5 mol% ≦ X ≦ 9 m
ol%, 91 mol% ≦ Y ≦ 95 mol%, X + Y = 1
00 mol%.

Here, the composition ranges of the ZrO ₂ powder and the glass powder are set to 5 mol% ≦ X ≦ 9 mol%, 91 mol%
≦ Y ≦ 95 mol% is because the ZrO ₂ powder is 9 mo
When the amount exceeds 1% and the glass powder becomes less than 91 mol%,
Luke no longer obtained dense sintered body by firing 900 ° C., the ratio
When the dielectric constant εr deteriorates and the ZrO ₂ powder becomes less than 5 mol% and the glass powder exceeds 95 mol%, 900 ° C.
This is because foaming, warping, and deformation are caused in the firing of.

Next, in this low-frequency sintering ceramic composition for high frequency, the main component of the glass powder is SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , (B
_a a, _Ca b) O, consists TiO _2, SiO
₂ (A), Al ₂ O ₃ (B), B ₂ O ₃ (C), (Ba
_{a, Ca} b) the molar ratio of O (D) and _TiO 2 (E) is, 15mol% ≦ A ≦ 70mol% , 0mol% <B
≦ 15mol%, 0mol% <C ≦ 10mol%, 5m
ol% ≦ D ≦ 60mol%, 10mol% ≦ a ≦ 90m
ol%, 10 mol% ≦ b ≦ 90 mol%, a + b = 1
00 mol%, 4 mol% ≦ E ≦ 6.2 mol%, A +
It is preferable that B + C + D + E = 100 mol%.

Here, the composition range of SiO ₂ (A) is 1
The reason for setting 5 mol% ≦ A ≦ 70 mol% is that when the SiO ₂ content is less than 15 mol%, the glass component does not vitrify, and when the SiO ₂ content exceeds 70 mol%, 900 ° C.
This makes it impossible to obtain a dense sintered body by firing.

The composition range of Al ₂ O ₃ (B) is set to 0
mol% <B ≦ 15 mol% is that the glass component does not vitrify when Al ₂ O ₃ is 0 mol%, and Al ₂ O ₃
If it exceeds 15 mol%, a dense sintered body cannot be obtained by firing at 900 ° C.

The composition range of B ₂ O ₃ (C) is 0 m
ol% <C ≦ 10 mol% is that B ₂ O ₃ is 0 m
ol% In dense sintered body in the firing of 900 ° C. can not be obtained, when the B ₂ O ₃ exceeds 10 mol%, is foamed, warping, because so deformed in the sintering of 900 ° C..

The reason why the composition range of (Ba _a , C _ab ) O (D) is 5 mol% ≦ D ≦ 60 mol% is that (B
If a _a , C _ab ) O is less than 5 mol%, a dense sintered body cannot be obtained by firing at 900 ° C., and (Ba _a , C _ab ) O
Exceeds 60 mol%, the temperature coefficient τ of the relative permittivity ε _r
This is because ε deteriorates.

The composition range of BaO (a) and CaO (c) is set to 10 mol% ≦ a ≦ 90 mol%, 10 mol
The reason that 1% ≦ b ≦ 90 mol% is that BaO is 10 mol
1%, and when CaO exceeds 90 mol%, 9
When sintered at 00 ° C., a dense sintered body cannot be obtained.
Is more than 90 mol%, and if CaO is less than 10 mol%, foaming, deformation, and warping occur at 900 ° C. firing.

The composition range of TiO ₂ (E) is 4 m
ol% ≦ E ≦ 6.2 mol%. TiO ₂ is 4
When the TiO ₂ content is less than 6.2 mol%, the temperature coefficient τε of the relative permittivity εr deteriorates.
℃ fired at or dense sintered body can not be obtained, the dielectric constant
it is whether we εr is deteriorated.

The above-mentioned glass powder is produced by melting a glass component at a high temperature of, for example, 1400 to 1500 ° C., and dropping it into water to quench it, or flowing it onto an iron plate to quench it. However, other rapid cooling methods may be used. Further, each raw material of the above-mentioned glass components is not limited to oxides, and it is needless to say that any material such as carbonates and hydroxides that can be converted into oxides by firing can be used.

[0017]

First, the case of the first embodiment will be described. Each raw material of glass component (SiO ₂ , CaCO ₃ , BaCO
₃ , Al ₂ O ₃ , TiO ₂ , B ₂ O ₃ ) were weighed as shown in the column of Example 1 in Table 1, and these were thoroughly mixed by a ball mill to prepare a batch of glass components. did.

Next, the batch was placed in a crucible and 1600
The mixture was heated at a temperature of 1 ° C. for 1 hour to be melted, and the melt was poured on an iron plate and quenched to obtain a glass flake. Then, this glass piece is finely pulverized by a ball mill to have an average particle size of 0.4 to 1.0.
A glass powder of μm was obtained.

Next, this glass powder and ZrO ₂ powder were blended in a molar ratio as shown in Table 1, and these were put in a ball mill and mixed for 15 hours to obtain a homogeneous mixed powder.

Next, an organic binder (P
VA), and granulate the mixture.
Pressure molding at a pressure of 00 kg / cm ² , diameter 9.8 m
m, a disk-shaped molded product having a thickness of 0.6 mm was obtained.

Next, the molded product is placed on a zirconia setter and placed in a firing furnace at 350 ° C. in an air atmosphere.
For 6 hours to burn off the organic binder in the molded product. Thereafter, the furnace temperature was increased to 900 ° C., and the molded product was sintered at this temperature for 2 hours to obtain a porcelain body. .

Next, an Ag paste was applied to both main surfaces of the porcelain body and baked to obtain a measuring capacitor provided with a pair of electrodes. Then, for this capacitor, the relative permittivity ε _r , Q and the temperature coefficient τε of the relative permittivity ε _r were measured. The relative dielectric constants ε _r and Q are 20 ° C., 1 MHz, 1 V
measured under the conditions of the _rms, temperature coefficient τε of the dielectric constant epsilon _r is
It measured in the temperature range of -55 to + 125 ° C (based on 20 ° C). The results are as shown in the column of electrical characteristics in Table 1.

Tables 1 to 1 also describe conditions and results of Examples 2 to 21 and Comparative Examples 1 to 14. The ratio (mol%) of each raw material component in these examples is as described in the left column of these tables. The experimental method is the same as in Example 1. The results were as shown in the right column of these tables.

[0024]

[Table 1]

[0025]

[Table 1]

[0026]

[Table 1]

Next, a suitable range (mol%) of each raw material component will be examined with reference to the results shown in Tables 1 to 1. In addition, Examples 3, 4, described below.
Reference numerals 10, 11 and 14 are reference examples.

First, as shown in Examples 1 and 2 , Zr
O ₂ powder. 5 to 9 mol%, the glass powder is 91 ～95M
In the case of ol%, a desired porcelain composition is obtained. However, as shown in Comparative Example 1, the ZrO ₂ powder contained 0 mol
%, The glass powder is 100 mol%, foaming, warping and deformation occur at 900 ° C. Further, as shown in Comparative Example 2, when ZrO ₂ powder is 30 mol% and glass powder is 70 mol%, a dense sintered body cannot be obtained by firing at 900 ° C. Therefore, the ZrO ₂ powder (X)
The range of 5 mol% ≦ X ≦ 9 mol% is suitable, and the range of the glass powder (Y) is preferably 91 mol% ≦ Y ≦ 95 mol%.

Next, as shown in Example 13, SiO ₂
Is 10 mol%, a desired porcelain composition is obtained. However, as shown in Comparative Example 9, the SiO ₂
In the case of ol%, the glass component is not vitrified, and as shown in Comparative Example 10, when the SiO ₂ content is 75 mol%, a dense sintered body cannot be obtained by firing at 900 ° C. Therefore, SiO ₂ (A) contains 15 mol% ≦ A ≦ 70 mol
% Is preferred.

Next, as shown in Example 12, Al ₂ O
_{When 3} is 15 mol%, a desired porcelain composition is obtained. However, as shown in Comparative Example 7, Al ₂ O ₃
In the case of ol%, the glass component is not vitrified, and as shown in Comparative Example 8, when the Al ₂ O ₃ is 20 mol%, a dense sintered body cannot be obtained by firing at 900 ° C. Therefore, Al ₂ O ₃ (B) is 0 mol% <B ≦ 15 mol
% Is preferred.

Next, as shown in Example 11, B ₂ O ₃
Is 10 mol%, a desired porcelain composition is obtained. However, as shown in Comparative Example 5, B ₂ O ₃
In the case of 1%, a dense sintered body cannot be obtained by sintering at 900 ° C., and as shown in Comparative Example 6, 15 mol of B ₂ O ₃
In the case of 1%, foaming, warping, and deformation occur at 900 ° C. Therefore, B ₂ O ₃ (C) contains 0 mol% <
The range of C ≦ 10 mol% is preferred.

Next, as shown in Embodiments 14 and 15,
When (Ba _a , Ca _b ) O is 5 mol% or 60 mol%, a desired porcelain composition can be obtained. However, Comparative Example 11
As shown in ( ₁ ), when (Ba _a , Ca _b ) O is 0 mol%, a dense sintered body cannot be obtained by firing at 900 ° C.
As shown in Comparative Example 12, (Ba _a , Ca _b ) O was 70 m
For ol%, the temperature coefficient τε of the dielectric constant epsilon _r is +75
ppm / ° C. Therefore, (Ba _a , Ca _b ) O
(D) is preferably in the range of 5 mol% ≦ D ≦ 60 mol%.

Next, as shown in Examples 16 to 19,
About 10 mol% to 90 mol% of aO, about 10 of CaO
In the case of mol% to 90 mol%, a desired porcelain composition is obtained. However, as shown in Comparative Example 13, when BaO is approximately 5 mol% and CaO is approximately 95 mol%, 90%
A dense sintered body was not obtained by firing at 0 ° C., and Comparative Example 1
As shown in FIG. 4, when BaO is about 95 mol% and CaO is about 5 mol%, foaming, warping, and deformation occur at 900 ° C. Therefore, BaO (a) and CaO
(B) is 10mol% ≦ a ≦ 90mol%, 10mo
The range of 1% ≦ b ≦ 90 mol% is preferable.

Next, as shown in Examples 1 to 10 , Ti
O ₂ is the case of 4mol% ~ 6.2 mol%, the desired ceramic composition is obtained. However, as shown in Comparative Example 3,
When TiO ₂ is 0 mol%, the temperature coefficient τε of the relative dielectric constant εr deteriorates to +73 ppm / ° C., and as shown in Comparative Example 4, when TiO ₂ is 20 mol%, 900
A dense sintered body cannot be obtained by firing at ℃. Therefore, TiO
₂ (E) is preferably in the range of 4 mol% ≦ E ≦ 6.2 mol%.

[0035]

According to the present invention, a high frequency porcelain composition can be obtained by firing at a relatively low temperature of 900 ° C. or less, so that a metal having good electric conductivity such as Ag or Cu can be used as an internal conductor. It can be used, and therefore has the effect that Q can be increased.

Further, according to the present invention, a high-frequency porcelain composition can be obtained by firing at a lower temperature than in the prior art, so that the energy cost for firing can be reduced.

Further, according to the present invention, since the relative dielectric constant of the high-frequency ceramic composition is lowered, there is an effect that electrical characteristics in a high-frequency range can be improved.

[Table 1 ○ 1]

[Table 1 ○ 2]

[Table 1 ○ 3]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoto Narita 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Yuden Co., Ltd. (72) Inventor Jun Masuda 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Yuden Incorporated (72) Inventor Toshikazu Toba 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Yuden Co., Ltd.

Claims (1)

(57) [Claims] 1. A mixture of ZrO ₂ powder and glass powder, which is sintered, wherein the molar ratio of ZrO ₂ powder (X) to glass powder (Y) is 5 mol% ≦ X ≦ 9 mol%, 91 mol% ≦ Y ≦ 95 mol%, X + Y = 100 mol%, and the main component of the glass powder is SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , (Ba _a , C
a _b) O, consists _{TiO 2, SiO 2 (A)} , Al 2
O ₃ (B), B ₂ O ₃ (C), (Ba _a , Ca _b ) O
The molar ratio of (D) and TiO ₂ (E) is 15 mol% ≦ A ≦ 70 mol%, 0 mol% <B ≦ 15 mol%, 0 mol% <C ≦ 10 mol%, 5 mol% ≦ D ≦ 60 mol%, 10 mol% ≦ a ≦ 90mol%, 10mol% ≦ b ≦ 90mol%, a + b = 100mol%, 4mol% ≦ E ≦ 6.2 mol%, a + B + C + D + E = 100mol%, low-temperature low dielectric constant, characterized in that the range of the high frequency Sinterable porcelain composition.