JPH07201225A - Dielectric porcelain composite - Google Patents

Dielectric porcelain composite

Info

Publication number
JPH07201225A
JPH07201225A JP5335844A JP33584493A JPH07201225A JP H07201225 A JPH07201225 A JP H07201225A JP 5335844 A JP5335844 A JP 5335844A JP 33584493 A JP33584493 A JP 33584493A JP H07201225 A JPH07201225 A JP H07201225A
Authority
JP
Japan
Prior art keywords
dielectric
mol
capacitance
dielectric ceramic
ceramic composition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP5335844A
Other languages
Japanese (ja)
Inventor
Kaori Shiraishi
Shoji Yoro
香織 白石
昭二 養老
Original Assignee
Matsushita Electric Ind Co Ltd
松下電器産業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Ind Co Ltd, 松下電器産業株式会社 filed Critical Matsushita Electric Ind Co Ltd
Priority to JP5335844A priority Critical patent/JPH07201225A/en
Publication of JPH07201225A publication Critical patent/JPH07201225A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To provide a dielectric porcelain composite having excellent anti-fold resistance and dielectric strength, and reduced dependency of electrostatic capacity temperature characteristics on the baking temperature. CONSTITUTION:A composite is expressed by (SrxCayBaz)TiO3, where 55<=x<=0.85, 0.45<=y<=0.15. and 0<=z<=5.0 at a mole ratio of x+y+z=1. As additives, Bi2O3 by 0.5-8.0mol% and MgO by 0.5-2.0mol% are added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric ceramic composition for temperature compensation, and more particularly to a dielectric ceramic composition used for disk capacitors and trimmer capacitors.

[0002]

2. Description of the Related Art A trimmer capacitor is a variable capacitor whose capacitance can be arbitrarily adjusted by changing the contact area between a dielectric element (stator) having an electrode on one surface and a metal rotor as its counter electrode. . However, since the contact area is changed by rotating the adjusting pin with a driver, a considerable stress is applied to the dielectric element (stator). Further, as a technological trend, the height of the trimmer capacitor will be further reduced in the future, and it will be required to make the dielectric element (stator) thinner.

[0003]

However, (Sr
There is a problem that the dielectric strength of the dielectric element (stator) is weak only with the composition of the CaBa) TiO 3 and Bi 2 O 3 system, and the dielectric element (stator) cracks during the capacity adjustment when the thickness is reduced. Further, the dielectric breakdown voltage is also reduced by making the dielectric element thinner.

In addition to the thickness (Sr x Ca y Ba z )
TiO 3 and Bi 2 O 3 also have a problem that the firing temperature dependency of the capacitance temperature characteristic is remarkable.

The present invention eliminates the above-mentioned conventional drawbacks and provides a dielectric ceramic composition in which the bending strength is improved, the dielectric strength is improved, and the firing temperature dependence of the capacitance temperature characteristic is relaxed. With the goal.

[0006]

[Means for Solving the Problems] Solving these problems
Therefore, in the present invention, the general formula (SrxCayBaz)
TiO3And x, y and z represent molar ratios.
Then, when x + y + z = 1, the values of x, y, and z are 0.55 ≦ x ≦
0.85, 0.45 ≦ y ≦ 0.15, 0 ≦ z ≦ 0.5
Yes, Bi as an additive2O3Is 0.5-8.0 mol%
Furthermore, a dielectric material containing 0.5 to 2.0 mol% of MgO.
Porcelain composition, Bi as an additive2O3And Nb 2OFiveTo 0.0
Dielectric ceramic composition comprising 2 to 0.5 mol% and additive
Bi as an additive2O3And ZrO20.01-0.2mo
A dielectric ceramic composition comprising 1% is provided.

[0007]

In the general formula, (Sr x Ca y Ba z ) TiO 3 is represented, and x, y and z are molar ratios, and x + y + z
= 1 and the values of x, y, z are 0.55 ≦ x ≦ 0.85, 0.
45 ≦ y ≦ 0.15, 0 ≦ z ≦ 0.5, and the dielectric ceramic composition containing Bi 2 O 3 as an additive in an amount of 0.5 to 8.0 mol% further contains MgO in an amount of 0.5 to 2. By adding 0 mol%, the crystal grain size becomes uniform and small, and the bending strength is improved. In addition, the dielectric strength is 20 (kv / mm) to 30 (kv / mm) by adding Nb 2 O 5.
Can be Then, by adding ZrO 2 , the firing temperature dependence of the capacitance temperature characteristic can be relaxed.

[0008]

EXAMPLES Examples of the present invention will be described below.

The dielectric ceramic composition of the present invention is used for trimmer capacitors and the like. That is, as shown in FIG. 1, a metal rotor 4 having a semi-circular concave portion 3 formed on the lower surface thereof is mounted on a stator composed of a dielectric ceramic plate 2 having a semi-circular stator electrode 1 built-in inside near the surface. Then, the spring 6 is installed in the adjusting recess 5 formed on the upper surface of the metal rotor 4, and the cylindrical portion 7 at the center of the spring 6 is penetrated through the centers of the metal rotor 4 and the stator and caulked on the lower surface of the stator. It constitutes a trimmer capacitor.

The present invention provides a dielectric ceramic composition that constitutes the dielectric ceramic plate 2 as the stator of such a trimmer capacitor, which has excellent bending strength, excellent dielectric strength, and firing temperature dependence of capacitance. Is provided as a relaxation.

Specific examples of the dielectric ceramic composition of the present invention will be described below. (Example 1) SrTiO 3 , CaTi as starting materials
O 3 , BaTiO 3 , Bi 2 O 3 and MgO were weighed so as to have the composition ratio shown in (Table 1), wet-mixed with partially stabilized zirconia balls, and dehydrated and dried. Next 11
It was calcined at 00 ° C. for 2 hours. This calcined powder was wet-ground under the same conditions as wet mixing, and dehydrated and dried. An organic binder was added to this pulverized powder to make it homogenous, and then the powder was sized through a 32 mesh sieve and molded with a molding pressure of 1 ton / cm 2 into a diameter of 15 mm and a thickness of 0.4 mm using a die and a hydraulic press. Next, the molded disc is put into an alumina sheath covered with zirconia powder, and the temperature rising / falling rate is 400 in air.
° C / h, holding temperature 1300 to 1400 ° C, holding time 1 to
After firing for 4 hours, dielectric ceramic discs having composition ratios shown in sample numbers 1 to 30 of (Table 1) were obtained.

The thickness, diameter and weight of the thus obtained dielectric porcelain disc were measured, and the samples for measuring the dielectric constant, the goodness Q and the temperature coefficient of capacitance were both sides of the dielectric porcelain disc. A silver electrode was baked on the whole surface. Then, the dielectric constant, the goodness Q,
The temperature coefficient of capacitance is model 4 of the digital LCR meter.
275A (manufactured by Yokogawa Hewlett-Packard Co.) was used, and the measurement temperature was 20 ° C., the measurement voltage was 0.5 Vrms, and the measurement frequency was 1 MHz. The temperature coefficient of capacitance was obtained by measuring the capacitance at -25 ° C and 85 ° C and using the following formula.

TC = (C-Co) / Co × 1/110 ×
10 6 TC: Capacitance temperature coefficient (ppm / ° C.) Co: Capacitance at -25 ° C. (pF) C: Capacitance at 85 ° C. (pF) Further, the dielectric constant was calculated by the following formula.

K = 143.8 × Co × t / (D / 2) 2
/ Π K: Dielectric constant Co: Capacitance at 20 ° C (pF) D: Diameter of dielectric ceramic disk (mm) t: Thickness of dielectric ceramic disk (mm) Further, bending strength is shown in Fig. 2. As shown, 3 according to JIS
The point bending strength was measured. The test piece 9 is placed on the two fulcrums 8, and the dial gauge 1 in which the load point has a constant radius of curvature
The load was applied to the test piece 9 by 0. The maximum load when the test piece 9 was broken was read and determined by the following formula.

Bending strength = 3 PL / (2 wt 2 ) P: Maximum load when the test piece breaks (kgf / mm 2 ) L: Distance between fulcrums (mm) w: Width of test piece (mm) t: Test piece (Mm) The above measurement results are shown in Table 1 for each of sample numbers 1 to 30.

[0016]

[Table 1]

As can be seen from (Table 1), when SrTiO 3 is less than 0.55, Q decreases, and when it exceeds 0.80, the element body is reduced to become a semiconductor capacitor.
The capacity becomes large and the Q becomes extremely small. Further, the temperature characteristic on the minus side also becomes large.

When the added amount of BaTiO 3 exceeds 0.08, the Q is lowered and the temperature characteristic on the negative side is increased, which is not practical.

Next, when Bi 2 O 3 is less than 0.1 mol%,
Dielectric constant and Q are low without sintering. On the other hand, if it exceeds 8.0 mol%, the sinterability will deteriorate and the Q will decrease. Further MgO
Is less than 0.5 mol%, no improvement in bending strength is observed,
When it exceeds 2.0 mol%, a decrease in Q is observed. MgO
It is considered that the reason for improving the bending strength is that the addition of MgO suppresses grain growth and forms homogeneous crystal grains.

In this example, the titanic acid compound was used as the starting material for Sr, Ca, and Ba, but there is no significant difference in characteristics even if the oxide or carbonate and titanium oxide are used. At that time, 1
If calcination is performed at 000 ° C to 1200 ° C, stable characteristics with little variation can be obtained.

(Example 2) Nb 2 O 5 was weighed so as to have the composition ratio shown in (Table 2), and a sample was prepared by the same manufacturing method as in (Example 1).

With respect to the dielectric constant, the goodness Q and the temperature characteristic of capacitance, the same method as in (Example 1) was used. For the dielectric breakdown strength, a high voltage power supply PHS35K-3 type (manufactured by Kikusui Electronics Co., Ltd.) was used, the sample was put in silicon oil, and the dielectric breakdown voltage obtained at a step-up speed of 50 V / sec was used as the dielectric thickness. It was divided by to obtain the dielectric breakdown strength per 1 mm.

The above measurement results are shown in (Table 2) for each of the sample numbers 31 to 35.

[0024]

[Table 2]

As can be seen from (Table 2), the dielectric strength of the sample without Nb 2 O 5 is 20 (kv / mm),
The sample to which b 2 O 5 is added has improved withstand voltage. However, if it exceeds 0.5 mol%, the capacitance-temperature characteristic becomes large on the negative side, which is not practical.

(Example 3) ZrO 2 was weighed so as to have the composition ratio shown in (Table 3), and a sample was prepared by the same manufacturing method as in (Example 1). The electrical characteristics are the same as in the measuring method of (Example 1).

The above measurement results are shown in (Table 3) for each of sample numbers 36 to 40.

[0028]

[Table 3]

As can be seen from (Table 3), the sample without ZrO 2 has a very large firing temperature dependence, but 0.01
If it exceeds mol%, the firing temperature dependency becomes smaller. If it exceeds 0.2 mol%, sintering inhibition will occur.

In the examples, MgO, Nb 2 O 5 and ZrO are used.
Although 2 is added separately, it has been confirmed that even if at least two elements are added at the same time, the effect can be exhibited without impairing the characteristics of each.

[0031]

As is apparent from the above description of the embodiments, the present invention has the general formula (Sr x Ca y Ba z ) TiO 3
And x, y and z represent a molar ratio, x + y
+ Z = 1 and the values of x, y, z are 0.55 ≦ x ≦ 0.85,
0.45 ≦ y ≦ 0.15, 0 ≦ z ≦ 5.0, and (S
r x Ca y Ba z) Bi 2 O 3 as an additive with respect to TiO 3
Is 0.5 to 8.0 mol%, and MgO is 0.5 to 2.
0.02 The Bi 2 O 3 and Nb 2 O 5 a large dielectric ceramic composition comprising a bending strength of 0 mol%, and as an additive
A dielectric ceramic composition having a high withstand voltage of 0.5 mol% and Bi 2 O 3 and ZrO 2 as additives were added in an amount of 0.1%.
The present invention provides a dielectric ceramic composition of 01 to 0.2 mol% having a small capacitance firing temperature dependency.

[Brief description of drawings]

FIG. 1 is a sectional view of a trimmer capacitor using a dielectric ceramic composition of the present invention.

[Fig. 2] Similarly, an image diagram of bending strength measurement attachment

[Explanation of symbols]

 1 Stator electrode 2 Dielectric porcelain plate 3 Recessed part 4 Metal rotor 5 Adjustment recessed part 6 Spring 7 Cylindrical part 8 Support point 9 Test piece 10 Dial gauge

Claims (3)

[Claims]
1. The general formula (SrxCayBaz) Ti
O3And x, y and z represent a molar ratio, x
+ Y + z = 1, x, y, z values are 0.55 ≦ x ≦ 0.8
5, 0.45 ≦ y ≦ 0.15, 0 ≦ z ≦ 5.0,
(SrxCayBa z) TiO3As an additive to Bi
2O3Is 0.5-8.0 mol%, and MgO is 0.5-
A dielectric ceramic composition comprising 2.0 mol%.
2. The general formula (SrxCayBaz) Ti
O3And x, y and z represent a molar ratio, x
+ Y + z = 1, x, y, z values are 0.55 ≦ x ≦ 0.8
5, 0.45 ≦ y ≦ 0.15, 0 ≦ z ≦ 5.0,
(SrxCayBa z) TiO3As an additive to Bi
2O3Is 0.5 to 8.0 mol% and further Nb 2OFiveIs 0.0
A dielectric ceramic composition comprising 2 to 0.5 mol%.
3. The general formula (SrxCayBaz) Ti
O3And x, y and z represent a molar ratio, x
+ Y + z = 1, x, y, z values are 0.55 ≦ x ≦ 0.8
5, 0.45 ≦ y ≦ 0.15, 0 ≦ z ≦ 5.0,
(SrxCayBa z) TiO3As an additive to Bi
2O3Is 0.5-8.0 mol% and further ZrO2Is 0.0
A dielectric ceramic composition comprising 1 to 0.2 mol%.
JP5335844A 1993-12-28 1993-12-28 Dielectric porcelain composite Pending JPH07201225A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5335844A JPH07201225A (en) 1993-12-28 1993-12-28 Dielectric porcelain composite

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5335844A JPH07201225A (en) 1993-12-28 1993-12-28 Dielectric porcelain composite

Publications (1)

Publication Number Publication Date
JPH07201225A true JPH07201225A (en) 1995-08-04

Family

ID=18293030

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5335844A Pending JPH07201225A (en) 1993-12-28 1993-12-28 Dielectric porcelain composite

Country Status (1)

Country Link
JP (1) JPH07201225A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6510040B1 (en) 1999-11-01 2003-01-21 Tdk Corporation Multilayer ceramic electronic component
JP2006327840A (en) * 2005-05-23 2006-12-07 Tdk Corp Ceramic electronic component and its manufacturing method
JP2010530346A (en) * 2007-06-07 2010-09-09 ヴィシェイ インターテクノロジー インコーポレイテッド Ceramic dielectric formulation for broadband UHF antenna
JP2010215430A (en) * 2009-03-13 2010-09-30 Tdk Corp Dielectric ceramic composition and electronic component

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6510040B1 (en) 1999-11-01 2003-01-21 Tdk Corporation Multilayer ceramic electronic component
JP2006327840A (en) * 2005-05-23 2006-12-07 Tdk Corp Ceramic electronic component and its manufacturing method
JP2010530346A (en) * 2007-06-07 2010-09-09 ヴィシェイ インターテクノロジー インコーポレイテッド Ceramic dielectric formulation for broadband UHF antenna
JP2010215430A (en) * 2009-03-13 2010-09-30 Tdk Corp Dielectric ceramic composition and electronic component

Similar Documents

Publication Publication Date Title
KR100475347B1 (en) Dielectric ceramic composition and capacitor using the same
US4610969A (en) Low temperature sintered ceramic material for use in solid dielectric capacitors or the like, and method of manufacture
KR910009895B1 (en) Ceramic composition for reduction-reoxidation type semiconductor capacitor
US4607316A (en) Low temperature sintered ceramic capacitor with high DC breakdown voltage, and method of manufacture
EP1786005B1 (en) Dielectric ceramic composition, electronic device, and multilayer ceramic capacitor
JP3046436B2 (en) Ceramic capacitors
JP3028503B2 (en) Non-reducing dielectric porcelain composition
EP0740310B1 (en) Dielectric ceramic compositions
US6730624B2 (en) Non-reducing dielectric ceramic, monolithic ceramic capacitor using the same, and method for making non-reducing dielectric ceramic
KR100522220B1 (en) Dielectric ceramic composition having high dielectric constant and electronic parts using the same
US5571767A (en) Low fire X7R dielectric compositions and capacitors made therefrom
KR100201201B1 (en) Monolithic ceramic capacitor
EP0257653B1 (en) High dielectric constant ceramic material and method of manufacturing the same
EP0534378B1 (en) Non-reducible dielectric ceramic composition
JP3470703B2 (en) Non-reducing dielectric ceramic, multilayer ceramic capacitor using the same, and method for producing non-reducing dielectric ceramic
EP0412440B1 (en) Dielectric ceramic for microwave applications
JP3305626B2 (en) Dielectric porcelain composition and ceramic electronic component using this dielectric porcelain composition
JP2007022819A (en) Dielectric porcelain composition and electronic parts
US4394456A (en) Temperature-compensating ceramic dielectrics
EP0261419B1 (en) Semiconductive ceramic composition
US20070142209A1 (en) Dielectric ceramic composition, electronic device, and multilayer ceramic capacitor
JP2594320B2 (en) Dielectric ceramic composition
US4785375A (en) Temperature stable dielectric composition at high and low frequencies
JP5153069B2 (en) Dielectric porcelain
KR20020096983A (en) Dielectric porcelain composistion