JPH10272614A - Manufacture of bonded sintered product of high-purity ceramics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a bonded sintered product of high-purity ceramics by which it is possible to obtain an integrated sintered product of bonded ceramics by sinter-bonding unsintered high-purity ceramic moldings. SOLUTION: This method for manufacturing a bonded sintered product of high-purity ceramics comprises a molding step for molding a molding material containing high-purity ceramic powder and an organic binder, an adhesive layer forming step for forming an adhesive layer containing, preferably an identical organic binder to the organic binder contained in the molding material, on the surface of ceramic moldings obtained in the molding step, a laminating step for laminating other ceramic moldings to the ceramic moldings with the adhesive layer, and a sintering step for sintering the laminated moldings. Through the sintering step, the moldings are effectively bonded to each other to obtain a bonded sintered product. The thickness of the adhesive layer is preferably within the range of 0.5-20 μm, and the high level of bonding is obtained by adding ceramic powder to the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding and sintering high-purity ceramics, and more particularly to a method for manufacturing a high-purity ceramic bonded sintered body suitable for manufacturing a recessed high-purity ceramic substrate.

[0002]

2. Description of the Related Art Unsintered ceramic compacts are joined together, sintered and integrated into a ceramic joined sintered compact, and a glass compact or a ceramic compact containing glass is added and fired. Can easily be obtained. This ease is due to the fact that when the compacts made of glass or ceramic powder containing a relatively large amount of glass components are fired in a state in which the compacts are simply overlapped, the glass melts on the surface where the compacts are in contact with each other. This is due to the formation of a bond. On the other hand, even if the high-purity ceramic molded bodies containing no glass are fired in a stacked state in the same manner, the surfaces in contact with the molded bodies are not joined without being integrated because they do not contain glass. As described above, it has been conventionally difficult to manufacture a bonded sintered body of a high-purity ceramic.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and combines unsintered high-purity ceramic compacts by sintering to form an integrated ceramic joint sintered body. It is an object of the present invention to provide a method for producing a bonded sintered body of a high-purity ceramic for obtaining a body.

[0004]

According to the first aspect of the present invention, there is provided a molding step of molding a ceramic molding material containing a high-purity ceramic powder and an organic binder for molding to obtain a ceramic molded body. An adhesive layer forming step of forming an adhesive layer containing an organic binder for an adhesive layer on the surface of the obtained ceramic molded body; and forming the ceramic molded body through the adhesive layer on the ceramic molded body having the adhesive layer formed thereon. It is characterized by having a laminating step of laminating a body to obtain a laminated molded body, and a sintering step of sintering the laminated molded body. By using an adhesive layer made of a binder, it is possible to obtain a well-integrated bonded sintered body without causing peeling of a bonded portion or partial unbonded portion. A ceramic sintered body having a structure that required a work, which can be easily obtained by pasting a molded body which has been subjected to simple processing before sintering and sintering it. .

According to a second aspect of the present invention, in the first aspect of the present invention, the thickness of the adhesive layer after the laminating step is set to be 0.5.
Characterized in that it is in the range of 5 to 20 μm,
A more specific range of the thickness of the adhesive layer for obtaining a bonded sintered body having a good bonded portion is provided.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the same organic binder is used as the organic binder for molding and the organic binder for the adhesive layer. The integration can be performed more efficiently and reliably.

According to a fourth aspect of the present invention, in the first aspect of the present invention, in the bonding layer forming step, a material having a composition corresponding to at least a part of the composition of the ceramic molding material is used. In addition, it is characterized in that the joining portion can be more efficiently and reliably integrated.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The following steps are required in the method for producing a high-purity ceramic bonded sintered body of the present invention. An adhesive layer containing an organic binder (preferably the same organic binder as the organic binder contained in the molded body) is formed on the surface of the unsintered molded body made of the high-purity ceramic powder. This adhesive layer contributes to the integration of the surface where the molded bodies are bonded to each other, that is, the bonding surface of the sintered body. If the adhesive layer is not provided, the bonded surfaces may be peeled off during firing, or defects may occur on the bonding surface as a sintered body. The unsintered compacts to be joined on the surface on which the adhesive layer is formed are attached to each other. This step forms an unsintered high-purity ceramic compact. For example, a green body for a substrate having a depression can be easily formed by bonding green sheets having been subjected to predetermined hole processing. The bonded compact is sintered so as to obtain a desired density. Through the above steps, a high-purity ceramic bonded sintered body can be obtained.

The non-sintered high-purity ceramic compact of the present invention is other than glass having a purity of 99% or more, and may contain auxiliary materials and stabilizers necessary for sintering the ceramic. . For example, a preferred material is 99.9% Al ₂ O
_And ZrO ₂ to which a stabilizer such as Y ₂ O ₃ , MgO, CaO, or CeO ₂ is added.

The high-purity ceramic molded body to be bonded may be a molded body having a desired shape obtained by a molding method such as a dry pressing method or a doctor blade method, and the type of the molding binder is not limited.

An organic binder is used as a binder for the adhesive layer applied to the surface of the molded body. At this time, a binder compatible with the organic binder contained in the molded body to be bonded is selected. It is preferable to use the same organic binder that does not hinder degreasing during sintering. Also, as a method to promote the integration of the joining surface,
For example, the same ceramic powder as the compact or a sintering aid for the ceramic compact can be added to the organic binder for the adhesive layer.

The thickness of the adhesive layer formed by applying the adhesive made of the organic binder to the surface of the high-purity ceramic molded body and drying the applied adhesive must be in the range of 0.5 to 20 μm. If the thickness of the adhesive layer exceeds 20 μm, the high-purity ceramics on the bonding surface will not be in sufficient contact with each other and will not be sintered together. On the other hand, when the thickness is less than 0.5 μm, it is difficult to form an adhesive layer uniformly, and a partial unbonded state occurs on the bonded surface of the bonded sintered body.

An organic binder for an adhesive layer is applied to the surface of the high-purity ceramic molded body to be joined and dried, and then a pressing machine is used so that no gap remains on the bonded surface.
Here, bonding while heating is effective in integrating the bonding surfaces. Further, if air bubbles or the like are not generated on the bonding surface when the applied binder is dried, the molded body may be bonded before the applied binder is dried.

The bonded compact is sintered so as to obtain a desired density, whereby a high-purity ceramic bonded sintered body can be obtained.

Examples of the method for manufacturing a high-purity ceramic bonded sintered body according to the present invention will be described below in more detail with reference to comparative examples. High purity alumina (99.9%) powder, P
VB (polyvinyl butyral), triolein glycol, dibutyl phthalate, and ethyl alcohol are dispersed and mixed by a ball mill, and 0.2 is mixed with a doctor blade.
A green sheet having a thickness of mm was produced. A binder obtained by dissolving PVB with ethyl alcohol was uniformly applied to the surface of the green sheet using a screen printer.
The coating thickness at this time was set such that the layer thickness as an adhesive layer obtained by a drying step described later was in the range of 0.5 to 20 μm. After the applied binder was dried at 90 ° C. for 10 minutes, two grease sheets were overlapped with each other so as to sandwich the adhesive layer, and pressurized while heating to 100 ° C. The bonded green sheets were sintered in the air to obtain a high-purity alumina bonded sintered body. Similarly, 3 mol% Y
A bonded sintered body of ZrO ₂ to which ₂ O ₃ was added was also prepared. Each of the obtained bonded sintered bodies was fractured, and the fracture surface of the bonded portion was observed by SEM. Table 1 shows the results. In Table 1, those with good evaluation of the bonding surface are represented by ○, and those having a failure on the bonding surface are represented by x.

[0016]

[Table 1]

As shown in Table 1, the thickness of the adhesive layer was 0.5
When the thickness was 10 μm to 10 μm, the joint was satisfactorily joined. When the thickness of the adhesive layer was 0 μm or more than 20 μm, some unbonded portions were formed at the bonded portions, or they were separated without bonding at all.

[0018]

【The invention's effect】

Advantageous Effect of Claim 1: Even in the case of high-purity ceramics not containing glass, by using an adhesive layer made of an organic binder, bonding is successfully integrated without causing peeling of a bonded portion or partial unbonded portion. A sintered body can be obtained, and a ceramic sintered body having a structure that conventionally required complicated processing is bonded to a molded body that has been subjected to simple processing before sintering and sintered. Can be easily obtained.

Effect of Claim 2: A more specific range of the adhesive layer thickness for obtaining a bonded sintered body having a good bonded portion is provided.

According to the third aspect of the present invention, the organic binder contained in the molded article and the organic binder contained in the adhesive material layer are the same organic binder, so that the joint can be more efficiently and reliably integrated. be able to.

According to the fourth aspect, by adding a material having a composition contained in the molded body, such as ceramic powder, which is a main component of the molded body, to the adhesive layer, the joining portion can be more efficiently and reliably integrated. I can do it.

Claims (4)

[Claims] 1. A molding step of molding a ceramic molding material containing high-purity ceramic powder and an organic binder for molding to obtain a ceramic molding, and an adhesive layer on a surface of the ceramic molding obtained in the molding step. An adhesive layer forming step of forming an adhesive layer containing an organic binder for use, and bonding the ceramic molded body via the adhesive layer to the ceramic molded body on which the adhesive layer has been formed, thereby forming a bonded molded body. A method for producing a high-purity ceramic bonded sintered body, comprising: a bonding step for obtaining; and a sintering step for sintering the bonded molded body. 2. The method for manufacturing a high-purity ceramic bonded sintered body according to claim 1, wherein the thickness of the adhesive layer after the bonding step is in a range of 0.5 to 20 μm. . 3. The high-purity ceramic bonded sintered body according to claim 1, wherein the same organic binder is used as the organic binder for molding and the organic binder for the adhesive layer. Method. 4. The adhesive layer forming step according to claim 1, wherein a material having a composition corresponding to at least a part of the composition of the ceramic molding material is added to the adhesive layer. The method for producing a high-purity ceramic bonded sintered body according to any one of the first to third aspects.