JPH06219819A - Ceramic green sheet and ceramic substrate - Google Patents

Abstract

PURPOSE:To provide a ceramic green sheet having a high rate of filling and high strength and a dense ceramic substrate. CONSTITUTION:The objective ceramic green sheet contains a mixture of at least two or more kinds of (meth)acrylate polymers. At least one of the polymers has >=1 acid value and <100,000wt. average mol.wt. and at least one of the polymers has >=100,000wt. average mol.wt. The objective ceramic substrate is made of the ceramic green sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic green sheet and a ceramic substrate using the same.

[0002]

2. Description of the Related Art As a binder for ceramic green sheets, polymers of acrylic acid esters or methacrylic acid esters have been used in order to improve the sinterability. However, there is a problem in that the dispersion of the ceramic powder is poor and the sinterability is poor only with the acrylic ester or methacrylic ester polymer. Therefore, in order to improve the dispersion of the ceramic powder, it has been proposed to use an acrylic acid ester or methacrylic acid ester polymer having an acid value. However, depending on the molecular weight of the polymer, good filling rate or strength of the green sheet is obtained. No results were obtained, and there was the problem that the handleability and sinterability of the green sheet deteriorated.

[0003]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned drawbacks of the prior art, and newly provides a ceramic green sheet and a ceramic substrate which have hitherto not been known. Is.

[0004]

The present invention has been made to solve the above-mentioned problems, and is an organic binder obtained by mixing two or more kinds of polymer compounds such as (meth) acrylic acid ester polymers. Of the polymer compound, wherein at least one of them has an acid value of 1 or more and a weight average molecular weight of less than 100,000, and at least one of which has a weight average molecular weight of 100,000 or more. There is provided a ceramic green sheet characterized by the above, and a ceramic substrate obtained by firing the above ceramic green sheet.

Monomers constituting the polymer that can be used as the organic binder of the ceramic green sheet of the present invention are acrylic acid esters such as methyl acrylate and ethyl acrylate, methyl methacrylate, ethyl methacrylate and methacrylic acid. In addition to methacrylic acid esters such as butyl, 2-ethylhexyl methacrylate and stearyl methacrylate, monomers having a functional group such as 2-hydroxyethyl methacrylate and dimethylamino methacrylate can be used. One kind or two or more kinds of these monomers may be polymerized. The acid value can be introduced by a method of copolymerizing a carboxylic acid having a double bond between carbons such as acrylic acid, methacrylic acid, fumaric acid and maleic acid.

In the present invention, at least one of the polymers contained in the polymer compound is a polymer of one or more of the above-mentioned monomers and has an acid value introduced therein.
The weight average molecular weight of the polymer having this acid value introduced is less than 100,000, and particularly preferably 60,000 to 80,000. The acid value is 1 or more, preferably 1.5 to 10, particularly preferably 1.
5 to 5. The reason why the average molecular weight is less than 100,000 and the acid value is 1 or more is that when the acid value is less than 1, the dispersion is not good, and when the acid value is 1 or more, the molecular weight is 100,000 or more, the dispersion is also good. It will not happen. If the acid value exceeds 10, the carboxylic acid that does not participate in the dispersion of the ceramic powder remains and the compatibility with the binder to be mixed may deteriorate.

At least one of the polymers contained in the polymer compound is a polymer of one or more of the above-mentioned monomers and has a weight average molecular weight of 100,000 or more. It is more desirable that the average molecular weight is from 1 to 400,000. If the average molecular weight is less than 100,000, the strength of the green sheet becomes weak and a good green sheet cannot be obtained. Moreover, it is preferable that the acid value is not introduced. This is because it may be difficult to obtain a green sheet having both good filling rate and good strength.

The proportion of the polymer mixed is 10 to 90% by weight of the polymer having an acid value introduced, and the polymer having a weight average molecular weight of 100,000 or more and not having an acid value introduced is 9%.
It is preferably 0 to 10% by weight, but can be arbitrarily changed within this range. The mixing ratio may be appropriately changed to find the optimum mixing ratio such as the green sheet filling ratio and the strength.

By mixing at least two kinds of organic polymers in this way, the dispersion of the ceramic powder is good,
The green sheet strength and green sheet filling rate are also improved,
It was clarified that the handleability and sinterability of the green sheet were good.

In the green sheet using the organic binder of the present invention, a plasticizer can be used in combination so as to make the green sheet characteristics suitable. As the plasticizer, dibutyl phthalate, dioctyl phthalate, butylbenzyl phthalate,
Other commonly used plasticizers can be used.

Examples of the solvent used in the present invention include ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, alcohol solvents such as methanol, ethanol, propanol and butanol, aromatic solvents such as benzene, toluene and xylene. Chloroform, 1,
Halogen-based solvents such as 1,1-trichloroethane and 1,1,2-trichloroethylene, and freon-based solvents such as R-113 can be used alone or in a mixed system.

As the ceramics in the green sheet using the organic binder of the present invention, it is possible to use a single component such as alumina, mullite or cordierite, or a mixed system of one or more of these with glass powder as a filler. .

The ratio (weight ratio) of the binder to the ceramic powder is 3 for 100 parts of the ceramic powder.
-20 is preferable, and when the binder is less than 3, the dispersion is poor and a good green sheet is not obtained. When it exceeds 20, it may be difficult to decompose the binder during firing.

[0014]

【Example】

[Molding of green sheet] For 100 parts by weight of a raw material obtained by mixing 50 parts by weight of alumina and 50 parts by weight of borosilicate glass,
60 parts by weight of toluene, sample No. 10 parts by weight of a binder composed of a polymer compound having a composition of 1 to 11 and 2 parts by weight of dioctyl phthalate were added and mixed in a ball mill for 20 hours to obtain a slurry. Then, this slurry was formed into a thickness of 0.2 mm by a doctor blade machine and dried at 60 to 80 ° C. for 2 hours to obtain a green sheet. The sample number No. 1 to 5 are examples, and others are comparative examples.

[Evaluation of Green Sheet] The green sheets were pulled by a tensile tester and their cutting strengths were compared. Further, the green sheet was cut into 55 mm square, the thickness and the weight were measured to determine the green sheet density, and the filling rate was determined from the specific gravity of the ceramic powder for comparison. The evaluation results are shown in Table 1.

No. In 1 to 5, the green sheet (G
It can be seen that both the S) filling rate and the green sheet (GS) strength are good. No. 1 using one kind of polymer compound as a binder In 8 to 11, either the filling rate or the strength is not good.

No. In Nos. 6 to 7, two types of polymer compounds were mixed and used as a binder, but since the molecular weight and the acid value were not appropriate, good results were obtained in either the green sheet filling rate or the green sheet strength. I know there isn't.

[Preparation of Ceramic Substrate] Six green sheets were stacked and thermocompression bonded, and the temperature was raised at 300 ° C./hr, and
After holding at 50 ° C for 1 hour, the temperature was lowered at 300 ° C / hr to degrease the organic binders, the temperature was raised at 1600 ° C / hr, and the temperature was kept at 850 ° C for 10 minutes, then 1600 ° C / hr.
Then, the temperature was lowered to obtain a ceramic substrate. The bulk density of the obtained substrate was determined by the Archimedes method, and the relative density was determined from the powder density. The results are also shown in Table 1. It can be seen that a dense substrate was obtained for the samples corresponding to the examples.

[0019]

[Table 1]

[0020]

The organic binder of the present invention makes it possible to obtain a green sheet and a dense ceramic substrate in which the ceramic powder is well dispersed and the green sheet filling rate and green sheet strength are good.

Claims (3)

[Claims] 1. A ceramic green sheet using an organic binder prepared by mixing two or more polymer compounds, wherein at least one polymer compound has an acid value of 1 or more and a weight average molecular weight of 10 or more. Less than 10,000, and at least one of them has a weight average molecular weight of 100,000 or more. 2. A ceramic green sheet using an organic binder obtained by mixing at least two kinds of (meth) acrylic acid ester polymers, said (meth)
At least one of the acrylic acid ester polymers has an acid value of 1 or more and a weight average molecular weight of less than 100,000, and at least one of them has a weight average molecular weight of 100,000 or more. . 3. A ceramic substrate obtained by firing the ceramic green sheet according to claim 1 or 2.