JPS62145603A - Dielectric porcelain compound - 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 a dielectric ceramic composition that has a high dielectric constant, a small temperature coefficient, excellent quality, and high insulation resistance.

2. Description of the Related Art A dielectric material with a small temperature coefficient has been required as a capacitor element, and the following systems are known as dielectric ceramic compositions.

Mg0-Tto2-Coo system La203-2T 102-C102-CaT10s-
2102 series TtO3-BaTtO3-Bt. 03-La
2O3 system 5rZrOs-8rO-Nb205-CaTt
Problems to be solved by the O3-based invention However, these compositions have a low dielectric constant, and 5rZr○
3-3 ro-Nb206-CaTiO2 system also has poor quality.

Furthermore, there is a problem in that Pd cannot be used as the internal electrode of a multilayer ceramic capacitor containing Bi2O3.

The object of the present invention is to obtain a dielectric ceramic having a high dielectric constant, a small temperature coefficient, excellent quality, and high insulation resistance.

Means for Solving the Problem In order to solve this problem, the present invention provides the following methods:
This is a dielectric ceramic composition characterized in that the main component is a composition having a molar ratio within the range surrounded by .

FIG. 1 is a triangular diagram showing the composition range of the main components of the composition according to the present invention, and the reason for limiting the composition range of the main components will be explained with reference to the diagram. In region A, sintering becomes difficult and the dielectric constant, quality Q, and insulation resistance decrease. In region B, the temperature coefficient becomes too large on one side, making it impractical. C
In the OD region, where the temperature coefficient increases to the + side and the dielectric constant is small, sintering becomes difficult, and the dielectric constant, quality Q, and insulation resistance decrease. Also, in the range of O<m≦0.25, m
When the temperature coefficient is increased, the temperature coefficient shifts to the + side, and by selecting an appropriate composition, a composition with a large dielectric constant near the temperature coefficient NPO can be obtained. When m exceeds 0.26, sintering becomes difficult, and the dielectric constant, quality Q, and insulation resistance decrease. Also, 0.
In the range of 06≦n<1.00, when n is increased, the temperature coefficient shifts to the + side, and by selecting an appropriate composition, a composition with a large dielectric constant near the temperature coefficient NPO can be obtained. n
If it becomes less than 0.06, the temperature coefficient becomes large on one side and becomes impractical.

The present invention further includes manganese as the main component.

At least one selected from the group consisting of oxides of chromium, iron, nickel, and cobalt, MnO2,
It is possible to have a structure in which 0.05 to 1.00% by weight of the main component is added in terms of Cr203t Fe○, NiO, and Coo. These additives have the effect of improving the sinterability of porcelain, but if the amount added is less than 0.06% by weight, there is no effect, and if it exceeds 1.00% by weight, the dielectric constant decreases.

Function: By using the dielectric ceramic composition of the present invention, it is possible to obtain a dielectric ceramic having a high dielectric constant, a small temperature coefficient, excellent quality, and high insulation resistance.

Example This will be explained below using specific examples.

(Example 1) Chemically highly purified B a Co 3t T was used as the starting material.
102 tZro2. Nd2o3. 5m2o3 powder was weighed so as to have the composition shown in Table 1, and put into a rubber-lined ball mill equipped with an agate ball together with pure water for wet mixing. After this mixture was dehydrated and dried, 9 parts by weight of a 6% polyvinyl alcohol solution was added as a binder to the powder to make it homogeneous, and the powder was sized through a 32-mesh sieve. The sized powder was molded using a mold and a hydraulic press at a molding pressure of 1 ton/d, with a diameter of 16 shapes and a thickness of O*.
The molded product was molded to a size of 4 mm, placed in a high-purity alumina sagger, and fired in air at the temperature shown in Table 1 for 2 hours to obtain dielectric porcelain having the composition shown in Table 1.

The electrical properties of these samples are determined by baking silver electrodes on both sides of the sample, and determining the dielectric constant, goodness Q, and temperature coefficient using YHP Digital L.
Using CR meter model 4275A, measured temperature 26°
C9 measurement voltage 1. oV rms, measurement frequency 1 kt
Determined by measurement using &. Incidentally, the temperature coefficient was determined using the following formula based on the capacitance value at 25°C.

Temperature coefficient = (C8cc-C26i-c)/(C2cc×
60) xlo (ppm/”C’) insulation resistance is YHPH
Measure voltage using R meter model 4329A, C06
It was determined by measurement at 0V for 1 minute. Test conditions and results are shown in Table 1.

(Example 2) Chemically highly purified BaCO3*T1 was used as the starting material.
02 *ZrO2, Nd2o3. SmSm2o32○2
tCr 203. Feo.

Ni○ and Coo powders were weighed to have the composition shown in Table 2, and thereafter treated in the same manner as in Example 1 to obtain dielectric porcelain having the composition shown in Table 2. .

The testing methods for these samples were the same as in Example 1, and the test conditions and results are shown in Table 2.

Table 1 Effects of the Invention As described above, according to the present invention, a dielectric ceramic having a high dielectric constant, a small degree coefficient, an excellent quality Q, and a high insulation resistance can be obtained. Also, manganese.

Firing temperatures can be lowered by adding chromium, iron, nickel and cobalt oxides.

Furthermore, since the obtained dielectric ceramic has a high dielectric constant, the element body can be made extremely small, and it is effective for miniaturizing circuits.
Suitable for applications such as hybrid microcircuits.

[Brief explanation of drawings]

The figure is a triangular diagram showing the composition range of the main components according to the present invention.

Claims (2)

[Claims] (1) General formula xBaO-y [(TiO_2)_1_-_m(ZrO_
2)_m]-z[(Nd_2O_3)_1_-_n(S
m_2O_3)_n], {where x+y+z=1.00 (0<m≦0.25) 0.05≦n<1.00} x, y, z are each point a, b shown below , c, d. (2) at least one selected from the group consisting of oxides of manganese, chromium, iron, nickel and cobalt,
MnO_2, Cr_2O_3, FeO, NiO, respectively
and 0.05 to 1.00 of the main component in terms of CoO
The dielectric ceramic composition according to claim 1, characterized in that it contains the dielectric ceramic composition in an amount by weight.