JPS6237802A - 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 IQII
The present invention relates to a dielectric ceramic composition that has a high Ωcm 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 TiO3, with CaTiO3 and B a S
Those to which n O3, CaZr01, S r T i O3, etc. have been added have been used. This is a material with a high dielectric constant of 2,000 to 15,000 at room temperature. but,
These composition systems have a sintering temperature of 1300 to 1400
It had the drawback of being high in temperature. 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. Noble metals such as platinum and palladium had to be used, which do not melt, oxidize, or react with the dielectric.

The above points should be improved (, new Pb(Mg+z3Nbz
z3)0+Pb(Zr++zsNbz73)C1+
A pb'rio3-based composition was proposed (Japanese Unexamined Patent Application Publication No. 1983-1999).
27974).

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 less.

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+On, MgO1Nb
zOy, , TiO2, ZnO, MOO3, Cub, WO
s, BaC0,, Ca CO3, S r CO3, Mn
Prepare C0+, weigh them, and add Pb(Mg+,
z+Nbzz) O'3, Pb(Zr++zaNbz
/+) 03, PbTiO3, Pb(Cu+/zW+7
g) 0+, Ba(Cul/2Wl/2)03, Ca(C
u+/zW+zz)0+, 5r(Cu+z2W'+zz
)()+, p b(Z nlzgMOlzz) 03,
Ba(Zn+z2Mo+zz)03, Ca(Zn+yz
MO+y*>03, S r(Z n+/zMo+/z)
Each was blended so that it became 03. Next, P b T
iO3 was individually calcined at 950°C, and the other compositions were calcined at 850°C for 2 hours to obtain predetermined compound powders.

Next, the compound powder thus obtained, MgO and MnC0 were blended at the desired blending ratios shown in Table 1, 5 parts by weight of a vinyl acetate binder were added, and wet-mixed using a ball mill. After that, it was evaporated and dried and sized to form a powder, which was then molded into a disk with a diameter of 12 mm and a thickness of 1.5 mm at a pressure of 1 ton/cm. The samples were fired for 1 hour at each temperature listed in "Firing Temperature" in Table 2. Afterwards, Ag paste was baked at 800° C. as an electrode, 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 and dielectric loss tangent were measured at lKHzlVrms under the condition of 25℃, and the specific resistance was measured under the conditions of 25℃ and 85℃, 2 minutes after applying C, 500V/+nm. Regarding temperature characteristics, the rate of change was measured at 10°C and 85°C 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 X Pb(Mg+73Nbzz+)0+
Y Pb(Zn+73Nbzz3)0+ZPbTiOa
(However, X, y, z represent the weight% of each component, x+y+
Z-100,0), the range of the main 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
, 1.0, 0.5), further containing 1.0 parts by weight or less of MgO as a subcomponent, and further containing a composition represented by A(C+g74W+zz)03. 0.5 parts by weight or more and 5.0 parts by weight or less, and further contains 0.5 parts by weight or more and 5.0 parts by weight or less of a composition represented by B (Z n + zzMo + zz) 03 It is a composition. That is, the present inventors have already developed Pb(Mg+73Nbzz+)'03, p
b(Zn+z+Nbzzs)Os, PbTi0. However, the present invention further contains 1.0 parts by weight or less of MgO in this composition, and furthermore, A.
The composition represented by (Cu+/zW1/2)O3 is 0.5
Contains at least 5.0 parts by weight, B(Zn+/
The composition represented by zMo+zz)03 was mixed with 0. 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 volume-N temperature characteristics can be obtained. Note that A and B are one or more elements selected from Pb, Ba, Sr, and Ca.

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(Zn+
If 73Nbzz+)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
When T i Ox is more than 1,000% by weight, the sintering temperature is as high as 1,000° C. or more, the dielectric constant is less than 15,000, and tan δ also exceeds 3.0%, which is not preferable. Furthermore, as in sample number 8, PbTi0. is less than 0.5% by weight, the dielectric constant is 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, which does not contain MgO, the dielectric constant is 1.
It is less than 5000, which is not preferable. Furthermore, in sample number 16, in which MgO was added in an amount greater than 1.0% by weight,
The dielectric constant decreases significantly and the sintering temperature becomes 1000° C. or higher, which is not preferable. Furthermore, M n Oz is 0.5
In sample No. 18 in which more than % by weight was added, the specific resistance at high temperature was 101 Ωcm or less, which is not preferable. Furthermore, as in sample number 19, A(Cu+/zW+7z)O
If a is less than 0.5% by weight, the sintering temperature will be 1000°C or higher, which is not preferable. Furthermore, as in sample number 23, when A(CUI/2Wl/2)03 exceeds 5% by weight, the dielectric constant decreases significantly, tan δ also exceeds 3%, and the resistivity at room temperature and high temperature is IQIIΩcm. The following is not desirable. Furthermore, like sample number 20, B (
When ZnIyzMo+yz)03 is less than 0.5% by weight,
The sintering temperature is 1000°C or higher, which is not preferable. Furthermore, like sample number 24, B(Zn+zzMo+zz
) When 03 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 low as 3% or less, the specific resistance is as high as 1,011 Ωcm or more at room temperature and high temperature (85°C), and the sintering temperature is EIA standard Z 5 tJ with a low temperature of 950°C to 1000°C and a small rate of change in dielectric constant.
A dielectric ceramic composition satisfying the characteristics was obtained, making it possible to make ceramic capacitors, especially multilayer ceramic capacitors, smaller in size, larger in capacity, lower in cost, more energy efficient, and more stable in production.

[Brief explanation of the drawing]

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 (excluding 0), and further contains A(Cu_1_/_2W_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 a composition represented by B(Zn_1_/
The composition represented by _2Mo_1_/_2)O_3 was heated to 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, 1.0 parts by weight or less (not including 0) of MgO is contained as a subcomponent, and further A(Cu_1_/_2W_1_/
_2) 0.5 parts by weight or more of the composition represented by O_35.
It contains 0 parts by weight or less, further contains 0.5 parts by weight or more and 5.0 parts by weight or less of a composition represented by B(Zn_1_/_2Mo_1_/_2)O_3, and furthermore contains 0.5 parts by weight or less of manganese in terms of MnO_2. The dielectric ceramic composition according to claim 1, characterized in that the dielectric ceramic composition contains 5 parts by weight or less (not including 0). Here, A and B are one or more elements selected from Pb, Ba, Sr, and Ca.