JPH06215627A - Low-temperature sintered porcelain composition for high-frequency - Google Patents

Abstract

PURPOSE:To provide a low-temperature sintered procelain composition which can be manufactured by baking at a relatively low temperature of 900 deg.C or less by specifying each mole ratio range for a quartz powder, a glass powder and the main component of glass powder. CONSTITUTION:This composition includes quartz powder of 13 to 55 mol% and a glass powder of 45 to 87mol% and the glass power contains particularly SrO. The foregoing specific value in the range of the mole ratio of a quartz powder is set for the purpose of obtaining a compact sintered product by baking at a temperature of 900 deg.C, and the specific value for a glass powder is set for the purpose of preventing the foaming, the warping and the deforming from being brought about. Also, the main component of a glass powder includes SiO2, Al2O3, (Ba, Ca, Sr)O and TiO2, and the mole ratio of SiO2 and Al2O3 is specified for the purpose of obtaining a compact sintered product by baking at a temperature of 900 deg.C. BaO, CaO and SrO are specified for the purpose of preventing the generation of the foaming, the warping and the deforming and at the same time obtaining a compact sintered product, and also TiO2 is specified for the purpose of preventing the deterioration of the dielectric constant and the temperature coefficient of the dielectric constant.

Description

Detailed Description of the Invention

[0001]

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

[0002]

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

[0003]

Since these ceramic compositions have considerably high sintering temperatures of 1100 to 1600 ° C., for example, when they are used as dielectric materials for laminated ceramic capacitors, tungsten, molybdenum, Refractory metals such as palladium must be used. However, since these high melting point metals have low electric conductivity, there is a problem that when this laminated ceramic capacitor is used in a high frequency circuit, dielectric loss becomes large and Q is lowered.

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

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

Specifically, it is densely sintered by firing at a temperature of 900 ° C. or less, a relative permittivity ε _r of 10 or less, a Q of 500 or more, and a temperature coefficient τ ε of the relative permittivity ε _r of 0 ± 60 ppm / ℃
It is an object of the present invention to provide a low-temperature sinterable porcelain composition for high frequencies.

[0007]

The low frequency sinterable porcelain composition for high frequencies according to the present invention comprises a mixture of quartz powder and glass powder, which is sintered, and is composed of quartz powder (X) and glass powder (Y). ), The molar ratio of 13 mol% ≦ X ≦ 55 mol
%, 45 mol% ≦ Y ≦ 87 mol%, X + Y = 100
It is in the range of mol%.

As the quartz powder, α-quartz powder is preferable. In addition, the composition range of the quartz powder and the glass powder is 13 mol% ≦ X ≦ 55 mol%, 45 mol% ≦
Y ≦ 87 mol% means that the quartz powder is 55 mol%
And the glass powder content is less than 45 mol%, 90
A dense sintered body can no longer be obtained by firing at 0 ° C., the quartz powder content is less than 13 mol%, and the glass powder content is 87 mol%.
If it exceeds, the foaming, warping, and deformation will occur in firing at 900 ° C., or the relative permittivity ε _r will deteriorate to 10 or more.

Next, in this low-frequency sinterable porcelain composition for high frequencies, the glass powder has SiO ₂ , Al ₂ O ₃ , (Ba _a , Ca _b ,
Sr _c ) O, TiO ₂ and SiO ₂ (A), Al ₂
O ₃ (B), (Ba _a , Ca _b ) O (C) and TiO ₂
The molar ratio of (D) is 15 mol% ≦ A ≦ 70 mol
%, 0 mol% <B ≦ 15 mol%, 5 mol% ≦ C ≦
60 mol%, 0 mol% <a ≤ 80 mol%, 0mo
1% <b ≦ 80 mol%, 0 mol% <c ≦ 80 mol
%, A + b + c = 100 mol%, 4 mol% ≦ D ≦ 1
It is in the range of 5 mol% and A + B + C + D = 100 mol%.

Here, the composition range of SiO ₂ (A) is set to 1
5 mol% ≤ A ≤ 70 mol% means that when SiO ₂ is less than 15 mol%, the glass component does not vitrify, and when SiO ₂ exceeds 70 mol%, the temperature is 900 ° C.
This is because a dense sintered body can no longer be obtained by firing.

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

The composition range of (Ba _a , Ca _b , Sr _c ) O (C) is defined as 5 mol% ≤C≤60 mol% is that (Ba _a , Ca _b , Sr _c ) is less than 5 mol%. Then 9
A dense sintered body can no longer be obtained by firing at 00 ° C. (Ba
_This is because the temperature coefficient τε of the relative permittivity ε _r deteriorates when _a , Ca _b , Sr _c ) exceeds 60 mol%.

Further, BaO (a), CaO (c) and S
The composition range of rO (d) is 0 mol% <a ≦ 80 mol
%, 0 mol% <b ≦ 80 mol%, 0 mol% <c ≦
80 mol% means that BaO exceeds 80 mol%, CaO exceeds 80 mol%, and SrO is 80 mol%.
This is because if it exceeds mol%, foaming, deformation, and warpage occur in firing at 900 ° C., or a dense sintered body cannot be obtained by firing at 900 ° C.

The composition range of TiO ₂ (D) is 4 m.
ol% ≦ E ≦ 15 mol% means that TiO ₂ is 4 m
This is because if it is less than ol% or if TiO ₂ exceeds 15 mol%, the relative permittivity ε _r deteriorates or the temperature coefficient τ ε of the relative permittivity ε _r deteriorates.

The above-mentioned glass powder can be produced by melting the glass component at a high temperature of, for example, 1400 to 1500 ° C. and dropping it into water to quench it, or by pouring it on an iron plate and quenching it. However, a quenching method other than this may be used. Further, each raw material of the above-mentioned glass component is not limited to the oxide, and it is needless to say that it can be used as long as it can form an oxide by firing such as carbonate and hydroxide.

[0016]

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

Next, this batch was put into a crucible and placed at 1550.
The glass was heated at 1 ° C for 1 hour to be melted, and the melted material was dropped into water and rapidly cooled to obtain a glass piece. Then, the glass pieces were finely pulverized with a ball mill to obtain glass powder having an average particle diameter of 0.4 to 1.0 μm.

Next, the glass powder and α-quartz powder were blended in a molar ratio as shown in Table 1, and these were placed in a ball mill and mixed for 15 hours to obtain a homogeneous mixed powder.

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

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

Next, Ag paste was applied to both main surfaces of this porcelain body and baked to obtain a measuring capacitor having a pair of electrodes. Then, for this capacitor, the relative permittivity ε _r , Q and the temperature coefficient τ ε of the relative permittivity ε _r were measured. Relative permittivity ε _r and Q are 20 ℃, 1MHz, 1V
Measured under the condition of _rms , the temperature coefficient τε of the relative permittivity ε _r is
The measurement was performed in the temperature range of −55 to + 125 ° C. (20 ° C. standard). The results are shown in the column of electrical characteristics in Table 1.

Tables 1 to 1 also show the 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 are shown in the right column of these tables.

[0023]

[Table 1]

[0024]

[Table 1]

[0025]

[Table 1]

Next, referring to the results shown in Tables 1 to 1, a suitable range (mol%) of each raw material component will be examined.

First, as shown in Examples 1 to 11, quartz powder is 13 to 55 mol%, and glass powder is 45 to 87 m.
In the case of ol%, the desired porcelain composition is obtained. However, as shown in Comparative Example 1, 60 mol% of quartz powder,
If the glass powder is 40 mol%, a dense sintered body cannot be obtained by firing at 900 ° C. Further, as shown in Comparative Examples 2 and 3, quartz powder is 10 mol% and glass powder is 90 m.
In the case of ol%, foaming, warping, etc. occur at 900 ° C firing.
Deformation occurs or the relative permittivity ε _r deteriorates to 11.2. Therefore, the content of the quartz powder (X) is 13 mol% ≦ X ≦
A range of 55 mol% is preferable, and glass powder (Y)
Is preferably in the range of 45 mol% ≦ Y ≦ 87 mol%.

For the same purpose, the X-ray diffraction pattern of the porcelain composition of Example 7 was determined and it was as shown in FIG. That is, the crystal phase of this composition is SiO ₂
(Α-quartz), (Ba, Ca, Sr) Al ₂ Si ₂ O
₈ , TiO ₂ (Rutile), Sr ₂ TiSi ₂ O ₈
Met.

Next, as shown in Examples 12 to 15, S
When iO ₂ is 15 to 70 mol%, a desired porcelain composition can be obtained. However, as shown in Comparative Example 5, when SiO ₂ is 75 mol%, a dense sintered body cannot be obtained by firing at 900 ° C., and as shown in Comparative Example 6, SiO ₂ is 10 mol%. In this case, the glass component does not vitrify. Therefore, SiO ₂ (A) is 15 mol
The range of% ≦ A ≦ 70 mol% is preferable.

Next, as shown in Examples 15 to 21, A
When l ₂ O ₃ is 5 to 15 mol%, the desired porcelain composition is obtained in each case. However, as shown in Comparative Example 7, when Al ₂ O ₃ was 0 mol%, the glass component did not vitrify, and as shown in Comparative Example 13, Al ₂ O 3
_{When 3} is 20 mol%, a dense sintered body cannot be obtained by firing at 900 ° C. Therefore, Al ₂ O ₃ (B) is 0 m
The range of ol% <B ≦ 15 mol% is preferable.

Next, as shown in Examples 14 to 21,
When (Ba _a , Ca _b , Sr _c ) is 5 to 60 mol%,
In each case, the desired porcelain composition is obtained. However, as shown in Comparative Example 12, (Ba _a , Ca _b , Sr _c ) is 3 mol.
%, A dense sintered body could not be obtained by firing at 900 ° C., and as shown in Comparative Example 14, (Ba _a , Ca _b , S
When r _c ) is 65.0 mol%, the temperature coefficient τ ε of the relative permittivity ε _r becomes +75 ppm / ° C, which is poor. Therefore,
(Ba _a , Ca _b , Sr _c ) (C) is 5 mol% ≦ C ≦ 6
The range of 0 mol% is preferable.

Next, as shown in Examples 14 to 21, B
aO is 10 mol% to 80 mol%, CaO is 10 mo
1% to 80 mol%, SrO is 10 mol% to 80 mo
In the case of 1%, the desired porcelain composition is obtained. But,
As shown in Comparative Example 8, BaO is 10 mol%, CaO
Is 90 mol% and SrO is 0 mol%, 900
A dense sintered body could not be obtained by firing at ℃, and as shown in Comparative Example 9, BaO was 90 mol% and CaO was 0 mol.
%, SrO is 10 mol%, foaming, warpage, and deformation occur during firing at 900 ° C., and as shown in Comparative Example 10, BaO is 0 mol%, CaO is 10 mol%, and Sr is SrO.
When O is 90 mol%, foaming, warping, and deformation occur at 900 ° C. firing. Therefore, BaO (a), Ca
O (b) and SrO (c) are 0 mol% <a ≦ 80 m
ol%, 0 mol% <b ≦ 80 mol%, 0 mol% <
The range of c ≦ 80 mol% is preferable.

Next, as shown in Examples 1 to 5 and 17 to 20, when TiO ₂ was 4 mol%,
As shown in Nos. 14 and 21, when TiO ₂ is 15 mol%, a desired porcelain composition can be obtained. But,
As shown in Comparative Example 4, when TiO ₂ was 3 mol%, the temperature coefficient τ ε of the relative dielectric constant ε _r deteriorated to +83 ppm / ° C., and as shown in Comparative Example 11, TiO ₂ was 2 mol% or less.
In the case of 0 mol%, the relative permittivity ε _r deteriorates to 12.4, and the temperature coefficient τ ε of the relative permittivity ε _r is -126 ppm / ° C.
Becomes worse. Therefore, TiO ₂ (D) is 4 mol% ≦
The range of D ≦ 15 mol% is preferable.

[0034]

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

Further, according to the present invention, since the high frequency porcelain composition can be obtained by firing at a temperature lower than the conventional one, there is an effect that the energy cost for firing can be reduced.

Furthermore, according to the present invention, since the relative permittivity of the high frequency porcelain composition is lowered, there is an effect that the electrical characteristics in the high frequency range can be made good.

[Brief description of drawings]

FIG. 1 is an X-ray diffraction diagram for the porcelain composition of Example 7.

[Table 1 ○ 1]

[Table 1 ○ 2]

[Table 1 ○ 3]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Masuda 6-16-20 Ueno, Taito-ku, Tokyo Within Taiyo Denki Co., Ltd. (72) Inventor Riichi Toba 6-16-20 Ueno, Taito-ku, Tokyo Within Taiyo Electric Co., Ltd.

Claims (1)

[Claims] 1. A mixture of quartz powder and glass powder, which is sintered, wherein the molar ratio of quartz powder (X) and glass powder (Y) is 13 mol% ≦ X ≦ 55 mol%, 45 mol% ≦ Y ≦ 87 mol. %, X + Y = 100mol% , in the range of the glass powder, when in accordance with the oxide equivalent representation, the main component _{is, SiO 2, Al 2 O 3} , (Ba a, Ca b, Sr c)
Consisting of O and TiO ₂ , SiO ₂ (A), Al ₂ O ₃
(B), (Ba _a , Ca _b , Sr _c ) O (C) and TiO ₂
The molar ratio of (D) is 15 mol% ≦ A ≦ 70 mol%, 0 mol% <B ≦ 15 mol%, 5 mol% ≦ C ≦ 60 mol%, 0 mol% <a ≦ 80 mol%, 0 mol% <b ≦ 80 mol%, 0 mol% <C ≦ 80 mol%, a + b + c = 100 mol%, 4 mol% ≦ D ≦ 15 mol%, A + B + C + D = 100 mol%, a low-temperature sinterable porcelain composition for high frequencies, characterized in that: