JPS6168370A - 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 a ceramic composition, particularly a ceramic composition suitable for multilayer ceramic capacitors, which has a high dielectric constant that can be sintered at a low temperature of 100°C or less. (Prior Art) It is well known that dielectric ceramic compositions containing paricum titanate (BaTIOl) as a main component have been widely put into practical use as conventional dielectric ceramic compositions used in laminated ceramics and capacitors. The main component of BaTiOs t" is sintered at a high temperature of 1300 to 140 G°C. When used in a multilayer capacitor, a material 1 that can withstand this sintering temperature is used as an internal electrode, such as platinum or palladium. K is the sintering temperature of porcelain, which requires the use of expensive precious metals and has the drawback of high manufacturing costs. It was desired to keep it as low as possible.

Therefore, already K, Pb (Fa2/3 W L/3)
Os'Pb (Fe 1/2 Nb 1/2)
Ox (Special Publication No. 55-34962) and (8rIIPb)
There are proposals such as Ti03Pb(Mgl/2W1/2)O, (%Kasho 52-21699).

The present inventors have developed a new porcelain composition different from these, Pb
We proposed a two-component composition consisting of ((Col/2W1/2)On ) and PbTiOs, and (pb (Co1/2)
W V2) 01)! (PbTi03)1-, when 1fC,x is 0.
35 to 0.75, it is clear that it can be sintered at a low temperature of 1000° C. or less, has a high dielectric constant, and exhibits good dielectric loss properties.

However, this two-component porcelain composition has a low resistivity;
90 (Object of the Invention) The object of the present invention is to provide a ceramic composition for multilayer capacitors that can be sintered at a low temperature of 100°C or less, has a high dielectric constant, low dielectric loss, and high specific resistance. There is a need to provide things.

(Structure of the invention) The present invention (Pb(Col/2W1/2)Os) (
:PbT10s:)1-.

A two-component porcelain composition [where 0.35≦X≦0−
753, P b (Mn ηW l/'
3) 0.2 mole to 4 mole added to the main component f: Characteristic.

(Example) The present invention will be explained in detail in Examples below.As co-starting materials, lead oxide (PBO) with a purity of 99% or more, cobalt carbonate (
Cacos), tungsten oxide (WOs), titanium oxide (Ti01), and manganese carbonate (MnCO3) were weighed to a predetermined blending ratio.Next, they were wet mixed in a ball mill and prefired at 750 to 775°C. ◎Then, it was further ground in a ball mill, and after drying, it was sized with an organic binder and pressed at 0.7 ton/cWI.
Four disks with a diameter of 16 mm and a thickness of about 2 mm were created, and silver electrodes were baked at 600°C on the top and bottom surfaces of the sintered disks, which were sintered in air at 880°C to 1000°C for 1 hour. Digital I, CR meter, frequency 1kHz, voltage 1vrm
The capacitance and dielectric loss (tan δ) were measured at s, and the dielectric constant was calculated. Next, a voltage of 50 μ was applied for 1 minute using a super insulation resistance meter, the insulation resistance was measured, and the specific resistance was calculated. In each case, four samples were measured at room temperature, and the average value was used as a representative value.

As is clear from the results shown in the table, the present invention provides P b (
Co 1/2 Wi, “2) Binary system Ic pb consisting of Os and pbTIOs (Mn2/'JWI/3)
By adding Ost-, the resistivity is significantly increased, the dielectric loss (tan δ) is improved, and the material can be sintered at a low temperature with a high dielectric constant, thus providing an excellent material as a ceramic composition for multilayer capacitors. 〇If the compounding ratio . pb, (Mn 2/'3 W 1/3
) If the amount of Os added is less than 0.2 modulus, the effect of improving specific resistance and dielectric loss (tan J) will be small, and if it exceeds 4 modalities, the effect of improving dielectric loss will be reduced.

In this example, carbonate was used as the cobalt or manganese compound, but oxides, oxalates, sulfates, hydroxides, etc. which decompose at high temperatures to form oxides may also be used.

(Effect of the invention)

Claims (1)

[Claims] Cobalt-lead tungstate [Pb(Co1/2W1/
2) A composition consisting of lead titanate [PbTiO_3] and lead titanate [Pb(Co1/2W1/2)O_3]_x[
When expressed as PbTiO_3]_1_-_x, 0.2% of Pb(Mn2/3W1/3)0_3 is added as a subcomponent to the main component composition in which X is in the range of 0.35≦X≦0.75.
A porcelain composition characterized in that it contains mol% to 4 mol%.