JPS63190765A - Manufacture of ceramic sintered body - 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 [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a ceramic sintered body, and particularly to an anti-adhesion liquid during firing and a method for applying the same.

(Prior art) In recent years, ceramic sintered bodies, which are made by molding ceramic powder into a predetermined shape and firing it at high temperatures, have been used in various products due to their various properties such as heat resistance and abrasion resistance. There is.

Among these ceramic sintered bodies, for example, aluminum nitride sintered bodies are used for various substrates such as circuit boards by utilizing their high thermal conductivity.

Such a sintered aluminum nitride-based substrate can be obtained by, for example, forming a thin plate shape using a doctor blade method, then cutting it into a predetermined shape, stacking the sheets, degreasing them, and then firing them.

Incidentally, since such a sintered aluminum nitride-based substrate is fired in a laminated manner, an anti-adhesion liquid is applied to prevent each layer from adhering to each other during firing.

Conventionally, this anti-adhesion liquid has been prepared by dissolving fine boron nitride powder in an alcoholic solvent together with appropriate amounts of a binder and a dispersant. .

(Problem to be Solved by the Invention) However, such an anti-adhesion liquid dissolves the binder contained in the ceramic molded body, so it could only be applied after the degreasing process. .

Therefore, it was necessary to cut the molded bodies, stack them, degrease them, apply an anti-adhesion liquid to each of the degreased bodies, stack them again, and then fire them. Since the degreased body is handled in such a manner that it is extremely difficult to handle it, there is a problem in that work damage such as chips and cracks may occur during the work. Further, there is also the problem that workability is reduced due to the number of steps required to apply an anti-adhesion liquid to each degreased body after cutting and the number of steps required for re-stacking.

The present invention has been made to solve this problem, and aims to provide a method for manufacturing a ceramic sintered body that is highly efficient and causes less damage during work such as chipping and cracking.

[Structure of the Invention (Means for Solving the Problems)] The method for manufacturing a ceramic sintered body of the present invention includes applying an anti-adhesion liquid for firing on the surface, in which fine mold release powder is dispersed in a non-polar dispersion medium. The ceramic molded body is cut into a predetermined shape, laminated, degreased, and fired.

The method of the present invention can be applied to ceramic molded bodies formed by various cold forming methods, and is particularly suitable for ceramic molded bodies containing a large amount of organic binder.

The anti-adhesive liquid for firing used in the present invention is mainly composed of V& powder for mold release, and this M powder for mold release is added to a non-polar i2 medium together with a binder and a dispersant as necessary. It is a mixture. As this mold release fine powder, various inorganic fine powders that are generally used at high temperatures can be used, and depending on the type of ceramic to be applied, boron nitride is selected as appropriate for nitride ceramics. It is something. In addition, examples of the non-polar dispersion medium include n-hexane, n-octane, benzene, carbon tetrachloride, etc. From the viewpoint of solubility of the inorganic fine powder, ru chain hydrocarbons having 6 or more carbon atoms are preferable, and especially N-hexane is preferred.

The anti-adhesion liquid is applied to the ceramic surface by spraying or brushing to a thickness of about 0.01 to 0.08 mm.

(Function) In the method for producing a ceramic sintered body of the present invention, a non-polar dispersion medium containing fine mold release powder dispersed is used as the anti-adhesion liquid for firing, so that it is possible to prevent mold release from occurring in the ceramic molded body. There is no risk of elution of the binder component,
This makes it possible to apply an anti-adhesion liquid to the molded body before the degreasing process, and there is no need to handle the degreased body by re-stacking or otherwise handling it.

(Example) Next, one embodiment of the present invention will be described.

Example First, boron nitride powder with an average particle size of 0.8 μm
1%, wax binder E-730 (trade name, Chukyo Yushi Co., Ltd.) 9.7% by weight, nonionic activator E as a dispersant
-787 (manufactured by Chukyo Yushi Co., Ltd., trade name) 3.2% by weight and 47.4% by weight of n-hexane as a dispersion medium were placed in a polyethylene container containing alumina balls, and mixed for about 24 hours using a bot roller. An anti-adhesion liquid for baking was prepared.

Next, 1 Mt of alumina and ittria were added as sintering aids and aluminum nitride (AβN) was thoroughly mixed.
10% by weight of an organic binder and 30% by weight of a solvent were added to the l[] mixture powder and thoroughly mixed in a bot mill to form a slurry. Using this slurry, a thin plate-shaped molded body was formed by a doctor blade method, and the above-mentioned anti-adhesion liquid for firing was applied to the surface of the molded body by a spray method to a thickness of about 0.1 B.

Next, this molded body was cut into a size of 80×40 m, and 10 sheets each were laminated. Then, this laminated molded body was degreased in a nitrogen gas atmosphere at a T of about 700°C (temperature increase rate of 100°C/hour I'Ql) for about 3 hours, and then in a nitrogen gas atmosphere at a temperature of about 1800°C.
It was fired for about 2 hours at 'C (heating rate: 145°C/hour).

When the appearance of the aluminum nitride sintered body thus obtained was inspected, it was found that there was no adhesion between the laminated layers, and no chips or cracks were observed.

・According to this example, since boron nitride powder is dissolved in n-hexane, which is a non-polar dispersion medium, as the anti-adhesion liquid for firing, there is a risk that the organic binder contained in the molded object will be eluted. This makes it possible to apply the anti-adhesion liquid for baking to the surface of the molded body before the degreasing process. This eliminates the need to handle the laminated degreased body after the degreasing process as in the conventional method, and can prevent defects such as chips and cracks. Furthermore, by omitting one work step, work efficiency can be improved.

[Effects of the Invention] As explained above, according to the method for manufacturing a ceramic sintered body of the present invention, by applying an anti-stick liquid for firing before the degreasing process, there is no need to handle the degreased body, and chips and cracks can be avoided. It is possible to significantly reduce the damage caused by such operations. In addition, work efficiency can be improved by omitting one work step.

Claims (4)

[Claims] (1) A ceramic molded body whose surface is coated with an anti-adhesive liquid for firing in which fine mold release powder is dispersed in a non-polar dispersion medium is cut into a predetermined shape and laminated, then degreased and fired. A method for producing a ceramic sintered body. (2) The method for producing a ceramic sintered body according to claim 1, wherein the ceramic sintered body is a nitride ceramic sintered body. (3) The method for producing a ceramic sintered body according to claim 1 or 2, wherein the mold release fine powder is boron nitride powder. (4) The method for producing a ceramic sintered body according to any one of claims 1 to 3, wherein the nonpolar dispersion medium is n-hexane.