JPS6237805A - 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 dielectric ceramic compositions, particularly those having a high dielectric constant of 15,000 or more and a sintering temperature of 950°C to 100°C.
Low as 0℃, and volume resistance at room temperature and high temperature is 1919
The present invention relates to a dielectric ceramic composition that is as high as cm or more and satisfies the Z5U characteristics of the EIA standard.

[Conventional technology and its problems]

Traditionally, Ba has been used as a high dielectric constant ceramic capacitor material.
Mainly composed of TiOs, with CaTiO3 and BaSnO
3. Materials to which CaZrOz, SrTiOs, etc. have been added have been used. This means that the dielectric constant at room temperature is 2000-'
It is an expensive material at 15,000 yen. However, these composition systems had the disadvantage that the sintering temperature was as high as 300 to 1400°C. This increases the cost of firing, and furthermore, in multilayer porcelain capacitors, multiple raw porcelain sheets with electrodes formed in advance are stacked and then fired, so electrode materials cannot be used at high temperatures of 1300°C or higher. Precious metals that do not melt, oxidize, or react with dielectrics,
For example, platinum or palladium had to be used.

In order to improve the above points, we newly added Pb(Mg1/+Nb2
/:+) 03Pb(Zn+73Nb2/+)03P
A bTiO3-based composition was proposed (Japanese Patent Application Laid-Open No. 57-27
Publication No. 974).

This composition has a dielectric constant of 10,000 or more and a sintering temperature of 1
A characteristic of 030 to 1150°C was obtained.

However, a high value of dielectric constant was also desired.

Furthermore, it has been desired to be able to perform stable sintering at a low temperature of 1000° C. or lower.

Furthermore, a composition that has good capacity temperature characteristics and satisfies the Z5U characteristics of the EIA standard has been desired.

Therefore, an object of the present invention is to provide a dielectric ceramic composition that can meet the above-mentioned demands.

〔Example〕

As starting materials, industrial Pb+04, MgO2Nb
205, T i Oz, ZnO, CuO1T a 20
s, Mo03B a CO3, CaCO3,5rCO
Prepare s, MnCO3, weigh cholera iiL, preliminarily add Pb
(Mg1/j'1b2/+) 03, Pb(Zn1/s
Nbz/+) 0+, PbTi0. , Pb(CuI7+
Ta2/s) 03, Ba(CulysTaz/s>O
s, Ca(Cu1/3Ta2/s) 03Sr(Cu1
/sTa2/a) Oz, Pb (Zn1/zMO+7z)
Os, Ba(Zn1/zMo1/*)()+, Ca(Z
nBzMO1/z) Os, 5r(Zn1/zMo1/
z) Each was blended so that it became Oi. Next, PbTiO
Sample No. 3 was calcined at 950°C, and the other compositions were individually calcined at 850°C for 2 hours to obtain predetermined compound powders. next,
The compound powder thus obtained and Mg'O and M
Blend nCO3 to each desired blending ratio in Table 1,
Five parts by weight of a vinyl acetate binder were added and wet mixed using a ball mill. After that, it is evaporated to dryness, sized to form a powder, and the powder is made into a powder with a diameter of 1 ton/cm".
It was molded into a disc with a diameter of 2 mm and a thickness of 1.5 mm. This disk was heated using an electric furnace with a lead atmosphere at the "firing temperature" shown in Table 2.
It was baked for 1 hour at each temperature described in . Later as an electrode A
The g paste was baked at 800° C., and the dielectric constant (ε), dielectric loss tangent (jan δ), and specific resistance (ρ) of each sample were measured, and the respective values are shown in Table 2. Here, the dielectric constant,
The dielectric loss tangent is I KHz I Vr'm under the condition of 25℃
The resistivity was measured at 25°C and 85°C.
The temperature characteristics were measured 2 minutes after applying C, 500 V/mm under the following conditions, and the rate of change at 10° C. and 85° C. was measured with 25° C. as a reference.

The samples marked with * in Tables 1 and 2 are outside the scope of this invention, and the others are within the scope of this invention.

(The following is a blank space) Based on each example shown in Tables 1 and 2, a three-component composition diagram (ternary diagram) of the main components is shown in the attached drawing. In addition,
In this drawing, the numbers marked with circles 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 three-component ceramic composition is XPb(Mg1/3Nb2/:+)0+
YPb(Zn1/3Nbz/5)03ZPbTiO3(
However, x and ySz represent the weight% of each component, and X+Y+Z
= 100.0), the range of the principal components (X, Y, Z) of this invention is A (89,0,1,0,1
0,0), B (80°0.10.0,10.0)
, C (59,5,40°0.0.5), D (9B,
5. Corresponds to the area surrounded by the four points 1.0, 0.5),
Furthermore, it contains 1.0 parts by weight or less of MgO as a subcomponent,
Furthermore, the composition represented by A(Cu1/zTaz/3)Os is contained in an amount of 0.5 parts by weight or more and 5.0 parts by weight or less, and furthermore a composition represented by B(Zn17□M O+ y□)03. This is a porcelain composition characterized in that it contains 0.5 parts by weight or more and 5.0 parts by weight or less. That is, the present inventors have already developed Pb(Mg1/3Nb2/3)03, p
b(Zn1/3Nbz/3) 03, P b T +
However, the present invention further contains 1.0 parts by weight or less of MgO in this composition,
Furthermore, the composition represented by A (Culi3Taz/3) 03 is contained in an amount of 0.5 parts by weight or more and 5.0 parts by weight or less, and the composition represented by B (Z nIytMo+yz)Os is contained in an amount of 0.5 parts by weight or more and 5.0 parts by weight or less. By containing 5 parts by weight or more and 5.0 parts by weight or less, the dielectric constant can be significantly improved, sintering can be performed at a lower temperature, and even better capacitance-temperature characteristics can be obtained. In addition, A and B are Pb, Ba, Sr, C
It is one or more elements selected from a.

Below, the reason for limiting the composition range will be described according to Table 1, Table 2, and the drawings. Like sample number 1, Pb(Zn1
If /5Nbz/3)03 is less than 1.0% by weight, the sintering temperature will be as high as 1,000° C. or higher, and a dielectric constant of 15,000 or higher cannot be obtained. Also, like sample number 4, P b T
When iO is more than 10% by weight, the sintering temperature is as high as 1000°C or more, and the dielectric constant is less than 15000.
Further, tan δ is also unfavorable if it exceeds 3.0%. Furthermore, as in sample number 8, P b T i 03 is 0.
If it is less than 5% by weight, the dielectric constant will be low and less than 10,000. Furthermore, as in sample number 11.13, when the sample is located above and to the 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, in sample number 14 in which MgO is not added, the dielectric constant is less than 15,000, which is not preferable. Furthermore, M
Sample No. 16 with gO added in an amount greater than 1.0% by weight
In this case, the dielectric constant decreases significantly and the sintering temperature is 1000
℃ or higher, which is not preferable. Furthermore, in sample No. 18 in which more than 0.5% by weight of M n O 2 was added, the specific resistance at high temperature was less than 10 Ωcm, which is not preferable. Furthermore, like sample number 19, A (Cu1/sTa
z/a) 03 is 0. If it is less than 5% by weight, the sintering temperature will be 1000°C or higher, which is not preferable. Furthermore, like sample number 23, A (Culz3Ta2z3) 03
When it exceeds 5% by weight, the dielectric constant decreases significantly and tan
δ also exceeds 3%, and specific resistance at room temperature and high temperature is 101
It is less than 1 Ωcm, which is not preferable. Furthermore, like sample number 20, B (Z n1/zMo1/z) 03
If it is less than 0.5% by weight, the sintering temperature will be 1000° C. or higher, which is not preferable. Furthermore, like sample number 24,
B(Z r+1/zMo1/z) When Os exceeds 5% by weight, the dielectric constant decreases significantly, the tan δ also exceeds 3%, and the resistivity at room temperature and high temperature becomes 1011 Ωcm or less, which is not preferable.

〔Effect of the invention〕

As described above, 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, the specific resistance at room temperature and high temperature (85°C) is as high as IQIIΩcm or more, and the sintering temperature is The dielectric ceramic composition has a low temperature of 950°C to 1000°C, a small rate of change in dielectric constant, and satisfies the Z5U characteristics of the EIA standard. This enabled cost reduction, energy conservation, and stable production.

[Brief explanation of drawings]

The drawing is a three-component composition diagram of the main components of the composition according to the present invention.

Claims (2)

[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_
4:68.05~69.60 MgO:2.41~4.00 ZnO:0.08~3.15 Nb_2O_5:24.01~26.66 TiO_2:0.13~2.59, and In the three-component composition diagram, [Pb(Mg_1_/_3Nb_2_/
_3) O_3, Pb(Zn_1_/_3Nb_2_/_
3) The blending ratio (% by weight) of O_3, PbTiO_3] is
A (89.0, 1.0, 10.0), B (80.0, 1
0.0, 10.0), C(59.5, 40.0, 0.5
), D (98.5, 1.0, 0.5) When the dielectric ceramic composition selected within the area surrounded by the four points is 100 parts by weight, 1.0 parts by weight of MgO as a subcomponent. Contains the following (not including 0), and further contains A (Cu_1_/_3Ta_
2_/_3) Contains 0.5 parts by weight or more and 5.0 parts by weight or less of a composition represented by O_3, and further contains a composition represented by B(Zn_1_
/_2Mo_1_/_2) The composition represented by O_3 is 0
．． A porcelain composition containing 5 parts by weight or more and 5.0 parts by weight or less. Here, A and B are one or more elements selected from Pb, Ba, Sr, and Ca. (2) Said Pb (Mg_1_/_3Nb_2_/_3)
O_3-Pb(Zn_1_/_3Nb_2_/_3)O
_3-With respect to 100 parts by weight of the main component consisting of PbTiO_3, it contains 1.0 parts by weight or less (not including 0) of MgO as a subcomponent, and further contains A(Cu_1_/_3Ta_2_
/_3) 0.5 parts by weight or more of the composition represented by O_35
．． Contains 0 parts by weight or less, and further contains B(Zn_1_/_2M
o_1_/_2) Contains 0.5 parts by weight or more and 5.0 parts by weight or less of a composition represented by O_3, and further contains 0.5 parts by weight or less (excluding 0) of manganese in terms of MnO_2. The dielectric ceramic composition according to claim 1, characterized in that: Here, A and B are one or more elements selected from Pb, Ba, Sr, and Ca.