JPS60101803A - Composition for high dielectric constant porcelain material - 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 the Invention The present invention relates to compositions for producing high dielectric constant porcelain materials. In particular, the present invention relates to a composition for producing a small, large-capacity, high-standard ceramic capacitor material that has a high dielectric constant, a significantly small temperature change rate of the dielectric constant, and a good loss angle at high frequencies. .

Structure of the conventional example and its problems A BaTiOg ceramic material is a well-known high dielectric constant ceramic material (2). Such porcelain materials include BaTi0. with another titanate compound (e.g. 5rTi)
Oa, MgTiO3, Pb〒103 and/or C
aTi08), but all of these conventional porcelain materials have the disadvantage that when the dielectric constant is as high as 3000.4000, the rate of change in dielectric constant with respect to temperature changes increases to 50% or more. The sintering temperature during manufacturing is also 13
The temperature is as high as 60-1380℃.

Further, when the rate of change in dielectric constant with respect to temperature change is set to 10% or 20%, the dielectric constant is as low as 1000 or 2000, and there are many other drawbacks such as poor loss angle at high frequencies.

Purpose of the Invention The present invention aims to improve the above-mentioned drawbacks of BaTiOa-based ceramic materials, namely, to create a ceramic material that has a high dielectric constant, a small rate of change in dielectric constant with respect to temperature changes, and a good loss angle at high frequencies. It is an object of the present invention to provide a composition for producing a porcelain material which can be produced and sintered at a relatively low temperature and is suitable for mass production.

(3) Structure of the Invention The present invention uses BaT10. powder 94-99.5% by weight, NiO powder 0.05-0.7% by weight, Nb, 0. Powder 0.2-1
．． 5 weight its, CeO, powder 0.02-0.3 weight i%,
5iOJ) powder 0.02-03% by weight and Pb, Bi2
A composition for making a high dielectric constant porcelain material consisting of 0.05 to 1.5% by weight of Ti, O□8 powder.

BaTi0. used in the composition of the present invention. Is the particle size of the powder 0.2μ? It is preferable that the range is 7L to 07μ, and if it deviates from this range, the rate of change in dielectric constant with respect to temperature changes will increase, and the sintering temperature will become high, which is not preferable.

Moreover, BaTi0. If the proportion of powder exceeds 99.5% by weight, the loss angle of the sintered porcelain material at high frequencies becomes poor and the rate of change in dielectric constant becomes large. Further, if it is less than 94% by weight, the sinterability of the composition becomes unstable, which is not preferable. If the proportion of NiO powder used in the present invention exceeds 0.7% by weight, the rate of change in dielectric constant of the sintered porcelain material with respect to temperature change will become large; This is not preferable because the dielectric constant of the porcelain material decreases and the rate of change in dielectric constant also increases. Also, Nb, 0. When the proportion of powder exceeds 1.5% by weight, the loss angle becomes poor, and when the proportion of powder is less than 0.2% by weight, the rate of change in dielectric constant becomes large. Moreover, if the proportion of CeO powder exceeds 0.3% by weight, the loss angle becomes worse and 0.03% by weight.
If it is less than 0.02% by weight, the rate of change in dielectric constant becomes large, which is not preferable.

When the proportion of SiO□ powder exceeds 0.3% by weight, the rate of change in dielectric constant becomes large, and when it is less than 0.02% by weight, the dielectric constant decreases and the rate of change in dielectric constant becomes large, which is not preferable. Finally, Pb, Bi, Ti40. , the proportion of powder is 1.5% by weight
If it exceeds 0.05% by weight, the dielectric constant decreases, and if it is less than 0.05% by weight, the rate of change in dielectric constant becomes large, which is not preferable.

In preparing the composition of the present invention, first, an equimolar ratio of Ba
Mix CO3 and 110□, then heat the mixture to 1050℃
It is held at ~1200° C. for about 2 hours, dried and pulverized to produce BaTiO3 powder with a particle size of 0.2)'m to 0.7 μm. Next, NiO, Nb2O5, CeO2, 5in2° (5
) Pb, Bi2Ti, 0.8 powders are prepared and each is weighed so as to have the above composition ratio. These powders are mixed together in a wet manner using a hot mill lined with urethane resin and a urethane-lined ball to prevent impurities from being mixed.

When producing a porcelain material using the composition according to the present invention, a binder such as polyvinyl alcohol is added to the mixture prepared as described above, and the mixture is heated under an appropriate pressure, usually 1000 Kf.
/Gfl compression molding into the desired shape. The molded body is then sintered, and when the composition of the present invention is used, it is generally necessary to sinter it at a temperature of 1220°C to 1250°C for several hours, preferably 2 hours.

Naori aWhen preparing solid solutions of TiOl, Pb, Bi, Ti, and 0□ in advance, the respective raw material compounds are not necessarily equimolar, and one compound has 0.
It may be increased or decreased up to 5 moles.

Description of examples The present invention will be explained below with reference to Examples.

(6) Examples BaTi0.2 μm to 0.7 μm particle size. , N
iO, Nb, O.

Coo, , 8102 and Pb, B1ff1'[
Samples 1 to 15 were prepared by mixing powders 'i and O□ in the proportions shown in Table 1.

Add appropriate polyvinyl alcohol binder to each sample and apply a pressure of 1000Kf/d to a diameter of 12+++m and a thickness of 0.4mm.
It was compression molded into a 1 g LL disk. Then each disk is 122
It was baked at 0°C to 1250°C for 2 hours.

A silver electrode was applied to the sintered disk thus obtained, and 750
The electrical properties of each sintered disk were measured by baking at ~800°C. The results are shown in Table 2.

(7) Table 1 Table 2 (9) Reference example BaTi0. based porcelain material, namely MgTi0. , 5rTiO, , Pb'ri03 or CaTiO3 were prepared using the method shown in the example, and their electrical properties were measured. The components of each ceramic material are shown in Table 3, and the measurement results are shown in Table 4. show.

(11) Table 4 (12) Effects of the Invention In Tables 1 and 2, sample numbers 3 to 10 are samples within the scope of the present invention, and the others are samples of comparative examples.

As is clear from the data in Table 2, all of the sintered porcelain materials made from the compositions of the present invention are dense porcelains, and their electrical properties also have higher dielectric constants than conventional materials and comparative examples. , the high frequency loss angle is good, and the temperature change rate is also small and stable.

Further, the composition of the present invention can be sintered at a relatively low sintering temperature of 1220 to 1250°C, and has great industrial value.

Furthermore, as is clear from the data in Table 4 of Reference Examples, conventional magnetic materials had a large temperature change rate.

In contrast, the magnetic material according to the present invention has a small temperature change rate and is stable, and is clearly superior.

Patent applicant: Matsushita Electric Industrial Co., Ltd. Director Hikaru Yasutatsu = f

Claims (1)

[Claims] 1. Particle size in solid solution: 0.2) 1m to 0.7
μm of BaT10. 94-99.5% by weight of powder and Ni
O powder 0.05~07 weight, Nb, O, powder 0.2~
1.5% by weight, Ce0t powder 0.02-0.3% by weight,
S10. Powder 0.02-0.3% by weight and Pb, Bi
High dielectric constant porcelain material composition 0 consisting of 0.05 to 1.5% by weight of □T1.0□3 powder