JPS6231906A - 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] (Industrial application field) The present invention relates to a dielectric ceramic composition.

(Prior art) Conventionally, BaT has been used as a high dielectric constant ceramic capacitor material.
Mainly composed of i O3 and CaTi0a.

Those to which BaSnO3, CaZrO3, 5rTiO, etc. have been added have been used. These materials have a high dielectric constant of 2000 to 15000 at room temperature.

(Problems to be solved by the invention) These conventional composition systems have a sintering temperature of 13O0 to 1
It has the disadvantage of being as high as 400°C.

For this reason, the firing cost is high, and furthermore, when making a laminated porcelain capacitor, electrodes are formed on raw porcelain sheets in advance, and multiple sheets are stacked and fired, so this electrode material cannot be used. is 13O0℃
It was necessary to use a noble metal such as platinum or palladium that does not melt, oxidize, or react with the dielectric even at these high temperatures.

In order to improve the above points, the inventors of the present application first prepared Pb (Mg+z3Nbz/3)0 as a dielectric ceramic composition.
3 Pb (Zn+za Nbz/3)03 PbT
io, system composition (Japanese Patent Application Laid-Open No. 57-27974
issue).

This composition has a dielectric constant of 10,000 or more and a sintering temperature of 1
It was possible to obtain characteristics of 0.03 to 1150°C. However, there has been a desire to develop a ceramic composition that exhibits a higher dielectric constant.

Furthermore, the temperature characteristics of capacitance are also improved.
It was desired to meet IA standard Z5U.

Therefore, the main purpose of this invention is to
It is an object of the present invention to provide a dielectric ceramic composition which has a high temperature characteristic of capacitance of 5000 or more and satisfies the EIA standard Z5U, and has a high volume resistivity of IQIIΩcm or more at room temperature and high temperature.

(Means for solving the problem) This invention provides Pb (Mg+/+ Nbt/s)03
-Pb (Znlz+ Nbz/s) 03 Pb
In a ceramic composition made of a solid solution of TiO3, the individual oxide composition ratios (wt%) are: Pb3O468.05~69.60 MgO 2.41~4.00 ZnO0.08~3.15 Nb,o, 24 .01~26.66Tie,
0.13 to 2.59, and (P b (Mg+/3Nbz73) 03 , P
b (Zn1/3 Nbzz+) Os + P
The blending ratio (wt%) of bT i 03 ) is A (89
,0,1,0,10,0),B (80,0,10,0
,10,0) ,C(59゜5.40.0,0.5>
, D (9B, 5, 1.0° 0.5) When the main component selected from within the polygonal region with vertices is 100 parts by weight, MgO is 1.0 parts by weight as a subcomponent. Below (0
(excluding parts by weight), and further contains A (Cu I/3
T a 2/3) 03 (However, A is pb, Ba,
This is a dielectric ceramic composition characterized in that it contains a composition represented by at least 0.5 parts by weight and 5.0 parts by weight of at least one element selected from Sr and Ca.

In addition, manganese may be added as a subcomponent if necessary.
0.5 parts by weight or less (excluding 0 parts by weight) in terms of O□
It is a dielectric ceramic composition that is also allowed to contain.

(Effects of the Invention) According to the present invention, the dielectric constant exhibits a high value of 15,000 or more, the dielectric loss tangent is as small as 3% or less, and the dielectric constant is as low as 3% or less.
A dielectric ceramic composition with a high specific resistance of 1011 Ωω or more at 85°C) and a temperature characteristic of capacitance that satisfies the EIA standard Z5U can be obtained, and can be used to reduce the size and increase the capacity of ceramic capacitors, especially multilayer ceramic capacitors. It is possible to reduce costs and save energy.

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

(Example) As starting materials, industrial P bs 04 , Mg
O.

Nb, ' Os + Tie, + ZnO, Cub,
Ta.

Os , B a CO3+ S r CO3r C
a Prepare COs + MncO3, weigh them, and prepare pb(Mg+zi Nbtz+ )03+ in advance.
Pb (Zn+/s Nb*y3)Os, PbT
l03, Pb (Cul/3 Taa/3)03,
Ba (Cu+y3Tat/s)Os+Sr
(Cul/3 Taz/+)03. Ca (Cu
+7+ Ta, , )O, were blended respectively.

Next, PbT103 was heated at 950°C and other compositions (
P b (Mg+z+ Nbff1/3) 03,
P b (Zn+/3Nbz/z)03. Pb (
Cu+7+ Taz/3)03+ Ba (Cu+/3
Tat/s )Os + 5r(Cu+/+Taz
yz )03 + Ca (Cu+z3 Ta2/3
) 03) were individually calcined at 850° C. for 2 hours to obtain predetermined compound powders.

Next, the compound powder, which is the main component, and MgO and MnCO5, which are subcomponents, obtained in this way are blended in the desired mixing ratio shown in Table 1, and a vinyl acetate binder is added as a binder. 5 parts by weight were added and wet mixed using a ball mill for 10 to 20 hours. Thereafter, the resulting mixture was evaporated to dryness and sized into a powder, which was molded into a disk with a diameter of 12 mm and a thickness of 1° and 5 fins under a pressure of 1 ton/cJ. This disk was fired for 1 hour at each temperature listed in the "Firing Temperature" column of Table 2 using an electric furnace having a lead atmosphere. Ag paste was baked at 800° C. to form electrodes on both sides of the obtained porcelain disk, thereby producing measurement samples 1 to 22.

For each sample, dielectric constant (ε), dielectric loss tangent (tanδ)
and specific resistance (ρ) were measured, and the respective values are shown in Table 2. Note that the dielectric constant and dielectric loss tangent are at a temperature of 25°C,
It was measured under the conditions of a frequency of 1 kHz and a measurement voltage of I Vr, m, s, and the specific resistance was measured at a temperature of 25 °C and 8
Measurements were taken 2 minutes after applying D, C, 500V/m at 5°C, and the temperature characteristics were measured at 10°C and 85°C with 25°C as the standard. .

In Tables 1 and 2, samples marked with * are outside the scope of this invention, and the remaining samples are within the scope of this invention. That is, in Table-1 and Table-2, sample numbers 1, 4, 8, 11°13.14, 16, 18.1
9 and 22 are outside the scope of the invention, sample number 2.3
, 5, 6, 7°9.10, 12, 15.17.20 and 21 are within the scope of the invention.

Based on the results of each experimental example shown in Tables 1 and 2, a three-component composition diagram (ternary diagram) of the main components is shown in the drawing. In addition, the numbers marked with circles in this drawing represent each sample number.

In this drawing, a region indicating the blending ratio of the main components within the scope of the present invention is drawn as a rectangle having vertices A, B, C, and D. That is, the blending ratio in the above-mentioned three-component ceramic composition is
3 YPb (Zn+/3Nbzy3)03 ZP
bTiOs (x, y, z are weight% of each component
, and expressed as X+Y+Z=100°0), the range of the main component of this invention (X.

Y, Z) is A (89,0,1,0,10,
0), B (80,0,10,0,10,0), C(
59°5, 40. O, 0, 5), D (9B,
5. 1.0°0.5), and furthermore, when this main component is 100 parts by weight, MgO is added as a subcomponent up to 1.0 parts by weight (0 (excluding parts by weight), and further contains A (Cu1/3
Tagz3) Os (However, A is Pb, Ba.

This is a porcelain composition characterized by containing 0.5 parts by weight or more and 5.0 parts by weight or less of a composition represented by one or more elements selected from Sr and Ca.

That is, as mentioned above, the present inventors first developed PbC
Mgr/z Nbg/a ) Os * P b (
Zn+7z Nba/s )03+ PbTi 03
However, in this invention, the main component is within this composition, and MgO is further added as a subcomponent.
0 parts by weight or less (excluding 0 parts by weight), and furthermore, a composition represented by A (Cu+z3Taty3)Os (where A is one or more elements selected from Pb, Ba, Sr, and Ca). By containing 0.5 parts by weight or more and 5.0 parts by weight or less, a remarkable improvement in dielectric constant and good temperature characteristics of capacitance can be obtained. Also,
As a subcomponent, manganese is further converted to MnO2 and is 0.
．． By containing 5 parts by weight or less, specific resistance can be increased. The reasons for limiting the composition range of the dielectric ceramic composition according to the present invention will be described below with reference to the tables and figures.

Like sample number 1, P b (Znr/3Nbz/3
) 03 Chikitsu, if less than Qwt%, the sintering temperature is 1150℃
It is difficult to obtain a dielectric constant of 15,000 or higher.

Also, as in sample number 4, PbTiO3 has IQ, Qw
When the amount is more than t%, the sintering temperature is as high as 1150°C or higher, the dielectric constant is less than 15000, and tanδ
It also exceeds 3.0%, which is not preferable.

Furthermore, as in sample number 8, PbTiO3 was 0.
If it is less than 5 wt%, the dielectric constant is low and less than 10,000.

Furthermore, as in sample number 11.13, when the sample is located to the upper right of the B-C line in the ternary component diagram, the dielectric constant becomes extremely low and the tan δ also exceeds 3.0%, which is not preferable.

Furthermore, sample number 14 to which MgO was not added had a dielectric constant of less than 15,000, which was not preferable. Furthermore, in sample number 16 in which more than 1.0 wt% of MgO was added, the dielectric constant decreased significantly and the sintering temperature was 1.
The temperature is 150°C or higher, which is not preferable.

Furthermore, in sample number 18 in which more than 0.5 wt% of MnO was added, the resistivity at high temperature was IQllΩcIn
This is not desirable. Furthermore, A (Cu'
In sample number 19 where +ys T a 2/3 ) 03 is less than 0.5 wt%, the rate of change in relative permittivity at 85°C is greater than 156%, which does not satisfy EIA standard Z5U, and furthermore, A (Cu l/ 3 T a 2/3 ) 0
In sample number 22, in which 3 is more than 5 wt%, the resistivity and dielectric constant at room temperature and high temperature decrease significantly, both of which are unfavorable.

[Brief explanation of drawings]

The drawing is a three-component composition diagram showing the blending ratio of the main components of the composition of the present invention. Patent Applicant Murata Manufacturing Co., Ltd. Representative Patent Attorney Oka 1) Kei Zen (1 idiot) Procedural dispute official seal) June 9, 1985 1985 Patent Application No. 170155 2, Name of Invention: Dielectric Body porcelain composition 3, relationship with the amended person case Patent applicant address 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Name (623) Material Manufacturing Co., Ltd. Representative Village 1
) 4th year of Showa, agent 5540 fit Osaka (06) 76
4-5443 Address: 5-3 Tanimachi, Higashi-ku, Osaka
O address 7° Contents of amendment Table 1 in the detailed description of the invention in the specification is corrected as shown in the attached sheet. Amendment to the above procedure August 25, 1985 Patent Application No. 170155 2 Name of the invention Dielectric porcelain composition 3 Relationship to the case of the person making the amendment Patent applicant Address 2 Tenjin, Nagaokakyo City, Kyoto Prefecture Chome 26-10 Name (623) Material Manufacturing Co., Ltd. Representative Village 1
) 4th year of Showa, agent etc. 540! It! Osaka (06) 7
64-5443 Address: 5-3O, Tanimachi, Higashi-ku, Osaka, Japan August 5, 1988 (Delivery date) 7. Contents of the amendment As shown in the attached sheet, the above procedure amendment (Own ship's patent issued on June 9, 1988) Director General Uga Michibe 1, Indication of the case 1985 Patent Application No. 170155 2, Name of the invention Dielectric porcelain composition 3, Relationship with the person making the amendment case Patent applicant address Tenjin, Nagaokakyo City, Kyoto Prefecture 2-26-10 Name (623) Gyoda Seisakusho Co., Ltd. Representative Village 1
) 4th year of Showa, agent ■540 'IR Osaka (06) '7
64-5443 (Main) Address: 5-30 Tanimachi, Higashi-ku, Osaka-shi Voluntary correction 6, subject of correction

Claims (1)

[Claims] 1 Pb(Mg_1_/_3Nb_2_/_3)O_3
-Pb(Zn_1_/_3Nb_2_/_3)O_3-
In a ceramic composition made of a solid solution of PbTiO_3, the individual oxide composition ratios (wt%) are: Pb_3O_468.05-69.60 MgO2.41-4.00 ZnO0.08-3.15 Nb_2O_524.01-26.66 TiO_20.13 to 2.59, and [Pb(Mg_1_/_3Nb_2_/_3)O_3,
Pb(Zn_1_/_3Nb_2_/_3)O_3, P
The blending ratio (wt%) of bTiO_3] is A (89.0,
1.0, 10.0), B(80.0, 10.0, 10.
0), C (59.5, 40.0, 0.5), D (98.
Polygons A and B whose vertices are the points 5, 1.0, 0.5)
The principal components selected from the area surrounded by , C, and D are 100
When expressed as parts by weight, it contains 1.0 parts by weight or less (excluding 0 parts by weight) of MgO as a subcomponent, and further contains A(Cu
_1_/_3Ta_2_/_3)O_3 {However, A is one or more elements selected from Pb, Ba, Sr, and Ca}
A dielectric ceramic composition, characterized in that it contains 0.5 parts by weight or more and 5.0 parts by weight or less of a composition represented by the following. 2 Three-component system [Pb(Mg_1_/_3Nb_2_/_
3) O_3-Pb(Zn_1_/_3Nb_2_/_3
)O_3-PbTiO_3], 1.0 parts by weight or less of MgO (
(excluding 0 parts by weight), and further contains A(Cu_1_/
_3Ta_2_/_3)O_3 {However, A is Pb, B
0.5 part by weight or more and 5.0 parts by weight or less of a composition represented by one or more elements selected from a, Sr, and Ca, and 0.5 part by weight of manganese in terms of MnO_2. characterized by containing the following (not including 0 parts by weight):
A dielectric ceramic composition according to claim 1.