JPS6055921B2 - High dielectric constant porcelain composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to magnetic compositions, particularly porcelain compositions with high dielectric constants and low sintering temperatures.

Conventionally, barium titanate [Ba
It is well known that materials containing TlO3 as a main component have been widely put into practical use.

However, the sintering temperature for products whose main component is BATIO is usually a high temperature of 13 U℃ to 1400℃, and especially in the case of multilayer capacitors, internal electrodes whose main component is platinum or This method has the disadvantage of requiring the use of expensive metals such as palladium. Therefore, in order to make it possible to use inexpensive internal electrodes mainly composed of silver, etc., the sintering temperature must be as low as possible, especially 1.
There has been a strong demand for a dielectric material that can be sintered at temperatures below 0 μC.

An object of the present invention is to provide a composition that can be sintered at a temperature of 1000° C. or lower, has a significantly high dielectric constant, low dielectric loss, and high specific resistance.

The present inventors have already discovered that Pb(F) can be sintered at temperatures below 1000°C.
e213W1l3)Os and Pb(Fe112Nb112
) proposed a two-component high dielectric constant ceramic composition consisting of Os (Japanese Patent Application Laid-Open No. 52-87700).

This composition has excellent dielectric properties and is about to be put into practical use as a ceramic capacitor. However, the dielectric loss and resistivity were somewhat unsatisfactory, and the application had to be limited to a narrow range. The present invention uses this two-component composition as Pb(Fe213W113)x(Fel'2N
b1l2) When expressed as 1-x03, the blending ratio x is 0.
At least one element selected from among the metal elements Sb, Bi, V, Nb, and 'L is added to the main component composition in the range of 2≦x<, 0.5 as the first subcomponent by 0.01%. ~1.0
Contains % FA and also contains Mn and M as second sub-components.
0.01 to 1.0 at% of at least one element selected from the following metal elements: g, Co, Fe, Cr, Ni, and Zn.
By simultaneously containing these elements, it is possible to maintain a high dielectric constant, reduce dielectric loss, and increase specific resistance, thereby providing an excellent high-permittivity ceramic composition that is easy to mass-produce and is inexpensive.

The present invention will be explained in detail below with reference to Examples.

Examples Starting materials include lead oxide (PbO), iron oxide (F
e2O3), tungsten oxide (WO3), niobium oxide (Nb2O5), antimony oxide (Sb2O3), bismuth oxide (Bi2O3), vanadium oxide (V2O.)
, tantalum oxide (Ta2O5), manganese carbonate (MnC
*8 Magnesium oxide (MgO), cobalt oxide (COO), chromium oxide (Cr2O,), nickel oxide (NiO), and zinc oxide (ZnO) are used and weighed to a predetermined mixing ratio.

Next, after wet mixing in a ball mill, 7500C~85
After pre-firing at 0℃ and pulverizing this powder, approximately 0.7t
At a pressure of 0n/Cfl, the diameter is about 16mm and the thickness is about 10W!
After being pressure-molded into a round cylinder, it was sintered at 0°C to 0°C. The obtained sintered body was cut into disks of about 0.5 m, and then silver electrodes were baked onto them. Table 1 shows the relationship between the blending ratio and various properties of the porcelain composition thus obtained. Note: Sample numbers marked with * are not included in the present invention.

Here, the dielectric constant and dielectric loss were measured at a frequency of 1 KHz and a temperature of 20'C.

The specific resistance was measured at a temperature of 20° C. by applying 100 V DC. As is clear from Table 1, the first subcomponents are antimony (Sb), bismuth (Bi), and vanadium (
V), niobium (Nb), and tantalum (Ta), and contains manganese (Mn), magnesium (Mg), and cobalt (V) as a second subcomponent.
CO), iron (Fe), chromium (Cr), nickel (Ni
), zinc (Zn), thereby maintaining a high dielectric constant and reducing dielectric loss. Moreover, the specific resistance has been significantly increased, resulting in an improved high dielectric constant ceramic composition that is highly practical. Because the sintering temperature is low, below 1000℃, it is difficult to sinter! Not only will this significantly improve the durability of furnace materials and reduce manufacturing costs due to reduced electricity costs, but it will also lead to lower prices for the internal electrodes of large-capacity multilayer capacitors. There are materials that are extremely suitable for mass production. Note that the main component blending ratio X is 0. Sister Mitsuru or more than 0.5
Compositions in the range where the dielectric constant is lower than room temperature have a low dielectric constant at room temperature because their Curie points are significantly shifted toward higher or lower temperatures than room temperature.

In addition, the content of the first subcomponent and the second subcomponent is 0.
．． If it is less than 1.0 atomic %, the effect of improving dielectric loss and resistivity is small, and if it exceeds 1.0 atomic %, the dielectric loss becomes large. In the above examples, oxides were mainly used as raw materials, but it goes without saying that the same effect can be obtained by using raw materials that easily become oxides by sintering, such as carbonates. .

Claims (1)

[Claims] 1. Iron/lead tungstate [Pb (Fe2/3W1/3
)O_3] and iron/lead niobate [Pb(Fe1/2N
A two-component composition consisting of Pb[Fe
2/3W1/3)x(F/2Nb1/2)1-xO_3
When expressed as, antimony (Sb), bismuth (Bi), vanadium (V), and niobium are added as the first subcomponent to the main component composition whose blending ratio (Nb), tantalum (Ta) at least 0.01 atomic % or more based on the main component1
．． Manganese (Mn), magnesium (Mg), cobalt (Co) is contained as a second subcomponent.
), iron (Fe), chromium (Cr), nickel (Ni),
A high dielectric constant ceramic composition characterized in that it simultaneously contains at least one metal element selected from zinc (Zn) in an amount of 0.01 to 1.0 atom % based on the main component.