JP2005029462A - Method for manufacturing ceramic plate, ceramic plate and setter made of ceramic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a ceramic plate capable of easily and economically providing in a high yield the ceramic plate having sufficient strength and a favorable smooth surface capable of performing homogeneous firing treatment to a part to be fired of an electronic device component or the like when the ceramic plate is used as a setter and capable of firing a product to be fired into a smooth state having no warp when the product to be fired is fired in a state being held between ceramic plates. <P>SOLUTION: The method for manufacturing the ceramic plate has a forming process for forming a formed product by using a starting material containing a ceramic powder, an organic compound for imparting shape preservability to the powder and/or clay, a drying/firing process for firing the dried formed body at 1,300-1,800°C and a cutting process for cutting the obtained fired product to the plate having a uniform thickness. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a ceramic plate, a ceramic plate, and a ceramic setter using the same.

  In recent years, ceramic thin films with various properties have been developed and applied to a wide variety of ceramic electronic devices. In the production of these thin films, organic bonds are combined with the desired material composition in order to improve processability. A material (hereinafter referred to as “binder”) is generally added and molded, and it is necessary to remove the binder by heat treatment. Moreover, in order to add a subcomponent with respect to a main component in the desired state, a calcination process may be performed in advance. In the case of heat treatment or firing (hereinafter referred to as “heat treatment or firing” is referred to as “firing or the like”) in the case of using electronic device parts or the like to be fired for this purpose, a larger number of products to be fired are more efficiently produced than before. In order to improve the productivity by processing at the same time, a plurality of objects to be fired are loaded and stored in a firing furnace, and a ceramic setter (hereinafter simply referred to as “ "Setter") is used.

  By the way, in recent years, demands for improving the productivity of electronic device parts and improving the quality of products are becoming stricter, and further improvements are required for the firing process of electronic device parts. The setter used in the is no exception. In other words, it is required to prevent adverse effects such as the occurrence of uneven baking, contamination of impurities from the setter, reaction with the setter material, etc. It is done.

  Furthermore, depending on the type of electronic device component, the fired body obtained after the firing process may be required to be flatly fired without warping. For this purpose, a smooth flat surface (smooth surface) is required. There are cases where the ceramic plate is made easy and the object to be fired is sandwiched and fired. If there is an inexpensive ceramic plate having a smooth surface that can be used in this case, it is very effective.

  Here, in various fields using electronic device parts manufactured as described above, it is possible to improve the productivity of products using electronic device parts, that is, to reduce manufacturing costs, and to be more economical. There is an urgent need to obtain excellent products, and cost reduction is also required for various members such as setters used in manufacturing. Therefore, development of a ceramic plate that is inexpensive, excellent in durability, and has a good smooth surface is desired without reducing the quality and function required for the ceramic plate used in the above setter and the like. In addition, a larger number of objects to be fired can be stored in the baking furnace and processed intensively at one time. In addition, there is no contamination from the setter. There is a demand for a ceramic setter that is capable of performing uniform heat treatment and the like on an object to be fired and that is inexpensive and excellent in functionality.

  On the other hand, the applicants have already been able to remove a large amount of binder added in the molding process of electronic device parts more efficiently, and perform firing etc. while keeping the coexisting electrode material stable. As a flat plate-like setter, a setter made of an alumina ceramic plate having a plurality of linear fine through holes has been proposed. If such a setter is used, even when the amount of the object to be fired is increased, high uniform air permeability during firing is realized, and uniform temperature distribution and maintenance of the atmosphere gas uniformity can be achieved. Furthermore, the quality of the manufactured electronic device component is maintained uniformly, and an electronic device component which is a highly functional material is obtained (see Patent Document 1).

  Moreover, as a setter for dealing with downsizing of electronic material parts, there is a firing setter in which the thickness is reduced to 0.2 to 2 mm, an independent through hole is formed on the surface, and the theoretical density of the forming material is 95% or more. As a method of manufacturing such a setter, a sheet-like molded body is formed by a slurry casting method or a doctor blade method, and then the molded body is punched, and then fired. It is disclosed that a setter is obtained (see Patent Document 2).

  Further, as described below, there is a demand for a setter made of the same ceramic plate as described above in a field other than the electronic device component. In the past, high-precision metal-based and ceramic parts that have been manufactured by a press-forming method using a press have come to require precise parts having complicated shapes in various directions. These parts are starting to be manufactured. In such a method, by using a plastic material in which a binder is mixed with a metal-based powder material or a ceramic material, it is possible to perform injection molding, and the resulting injection-molded product having a desired shape is heat-treated to remove the binder. We have obtained precise metal systems and ceramic parts with complex shapes. In this case, a ceramic plate having a smooth surface that can be fired flat without warping may be desired.

  Therefore, in the manufacture of these parts, a setter made of a ceramic plate is used in the heat treatment process, and in this case as well as in the case of manufacturing the electronic device parts described above, the cost is low. The development of a ceramic plate with a smooth surface that is superior in functionality, ease of use, enables efficient and uniform heating and firing of the mounted components, and can perform flat firing is awaited. Has been.

JP 2002-145672 A JP-A-11-79853

  However, according to the study by the present inventors, the production method described in Patent Document 2 described above is very complicated, and the method cannot obtain a molded body thicker than 2 mm. On the other hand, if the thickness is less than 0.2 mm, the molded body is easily broken during or after the punching process, and a ceramic plate thinner than this cannot be formed. In particular, a material having a high through-hole ratio has a strong tendency, and even a material thicker than 0.2 mm does not have sufficient mechanical strength. There is also a problem that warpage occurs during the firing of the plate, and the above method cannot obtain a setter with a high yield. Furthermore, since the setter obtained above has a limited thickness, its use is limited, and it has not been possible to obtain a setter that can sufficiently cope with the diversity of the objects to be fired.

  On the other hand, although the setter manufacturing method described in Patent Document 1 described above is simple, basically, the setter is fired after being molded with a powder material imparted with plasticity (shape retention). As with the method described in Patent Document 2, warping occurs during firing, and a flat surface cannot be obtained unless polishing treatment or the like is performed thereafter, and flat firing without warping is performed at low cost. There was room for improvement in the objectives. Further, Patent Document 1 describes that a setter is formed by cutting a fired molded product thereafter, but Patent Document 1 discloses a setter having a plurality of fine linear through holes. It is not intended to obtain a setter made of a ceramic plate having high smoothness that enables firing of the object to be fired in a smooth state without warping.

  Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a setter that has sufficient strength and that can perform a process such as good and economical firing on various objects to be fired. An object of the present invention is to provide a method for producing a ceramic plate that can be provided simply and economically with a good yield. That is, when firing or the like is performed in a state where a large number of electronic device parts, metal parts, and ceramic parts (hereinafter referred to as “parts” in this specification) are placed before firing, It is possible to perform processing such as uniform firing on the material to be fired, and when the material to be fired is sandwiched between ceramic plates and used for firing, it is fired in a smooth state without warping. It is possible to provide a ceramic plate that is very useful as a setter. Another object of the present invention is to provide a setter having a high practical value that enables more intensive and uniform processing such as firing on a larger number of objects to be fired. Furthermore, an object of the present invention is to provide a manufacturing method capable of easily and economically obtaining a ceramic plate having excellent performance as described above, such as parts manufactured using the ceramic plate. The purpose is to improve the quality and productivity, and to contribute to the improvement of the quality of various products in which these parts are used and the achievement of economic efficiency.

  The above object is achieved by the present invention described below. That is, the present invention provides [1] a molding step of forming a molded article using a raw material containing at least a ceramic powder and an organic compound and / or clay for imparting shape retention to the powder; After drying the product, a drying and firing step of firing the dried molded product at a temperature of 1,300 to 1,800 ° C., and a cutting step of cutting the fired product obtained above into a flat plate having a uniform thickness And a method for producing a ceramic plate.

Preferred embodiments of the present invention include the following [2] to [6]. [2] In the cutting step, the cut surface of the fired product is cut so as to be a smooth surface with a flatness per 120 mm square of the ceramic plate of 90 μm or less and a centerline average roughness Ra of 1.0 μm or less. The manufacturing method of the ceramic board as described in said [1]. [3] The ceramic plate according to [1], wherein in the forming step, a molded product having a plurality of linear through holes in which the size of one hole is 0.07 to ⁴ mm ² is formed by an extrusion method. Manufacturing method.
[4] The method for manufacturing a ceramic plate according to any one of [1] to [3], wherein the cutting step is performed so that the thickness is 5 mm or less.
[5] The method for producing a ceramic plate according to any one of [1] to [4], wherein in the cutting step, cutting is performed using any of an inner circumferential slicer, a wire saw, and a band saw.
[6] The method for manufacturing a ceramic plate according to any one of [1] to [5], further including a polishing step of polishing at least a part of the surface of the ceramic plate after the cutting step.

Another aspect of the present invention is [7] a ceramic plate obtained by a manufacturing method having any one of the above-described [1] to [6].
Another aspect of the present invention is [8] a setter for holding an object to be fired in a firing furnace, wherein the ceramic plate is used for a part or all of the setter. Is a setter. The setter is preferably [9] in the vicinity of the outer periphery of the flat surface of the ceramic plate made of a flat plate having a uniform thickness and may have a plurality of linear through holes. Contiguous edges formed in a convex shape in the direction are provided, and at least three positions of the edges are provided with protrusions that are higher than the height of other parts of the edge, and the highest of at least three protrusions Examples include setters whose positions have substantially the same height. Furthermore, [10] formed in a convex shape in a direction perpendicular to the flat surface in the vicinity of the outer periphery of the flat surface of the ceramic plate made of a flat plate having a uniform thickness and may have a plurality of linear through holes. And a setter provided with a substantially continuous edge of substantially the same height.

  The flatness is a value measured by a grazing incidence laser interference method in a method guaranteed by NIST (United States Metrology Agency). Specifically, the measurement was performed in a non-contact manner with respect to the measurement sample using TROPE FlatRule 200 (manufactured by TROPE). The centerline average roughness is specifically a value measured using a contact-type surface roughness meter, Form Talysurf S3F, which is guaranteed by the JIS method, manufactured by Taylor Hobson.

  According to the present invention, a ceramic plate having a sufficient smoothness, without causing warpage in the production stage, and having a good smooth surface can be obtained simply and economically with a good yield. Furthermore, there is provided a method for manufacturing a ceramic plate that can easily form setters having various shapes suitable for various objects to be fired. That is, when the ceramic plate obtained by the method according to the present invention is used as a setter, it is possible to perform uniform firing or the like with no firing unevenness on many stacked objects to be fired. Further, when the object to be fired is sandwiched between the ceramic plates and used for firing, the firing can be performed flatly.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. When the ceramic plate obtained by the manufacturing method according to the present invention having the above-described configuration is used as a setter, the electronic device parts to be mounted on the setter as a fired product include capacitors, piezoelectric elements, ferrite elements, and high-frequency ceramics. Ceramic parts such as ceramic thin films (tapes or sheets) and bulk (those with a certain size) used in the formation of various ceramic electronic devices such as substrates It is done. In addition, as precision metal system and ceramic parts obtained by injection molding to be loaded as a material to be fired, it is fired after injection molding using a metal material such as stainless steel or titanium, or a material obtained by adding a binder to a ceramic material. And metal parts and ceramic parts obtained.

  All of the parts listed above are fine functional materials that have a fine shape and need to maintain extremely high quality. It is required that a uniform process is performed on each part, and a reliable, homogeneous and high-quality product is stably supplied. For this reason, in the firing process of these objects to be fired, productivity is improved by using a setter made of a ceramic plate, and at the same time, the adverse effect that may be exerted on the product by using the setter is avoided, and uniform. In addition, it is required that a sufficient firing process or the like be performed. Therefore, it is desired to develop an excellent method for producing a ceramic plate that can easily and economically provide various setters having materials and shapes that are optimal for firing a wide variety of objects to be fired.

  The ceramic plate according to the present invention can be used particularly effectively as a setter used in a process such as firing performed when manufacturing a precision functional part as mentioned above. The ceramic plate according to the present invention is a flat setter having a uniform thickness and a flat setter having a uniform thickness having a plurality of fine through-holes, which are suitable for manufacturing fine parts having a flat surface. It is particularly useful when. Further, in the vicinity of the outer periphery on the flat surface of the flat ceramic plate, there are continuous edges that are convex with respect to the flat surface, and at least three convex portions having substantially the same height are provided on the edge. If it has a setter, for example, it becomes possible to perform a process such as firing of the material to be fired more intensively and evenly on a material to be fired having a shape that easily rolls. However, the ceramic plate according to the present invention is not limited to these uses, and is not intended for parts of a specific shape or material, and is widely used for ceramic and metal materials that require firing or the like in general. It can be used across.

As a result of intensive studies on the above-described problems of the prior art, the present inventor has found that in the production of a ceramic plate, in the forming step (1), an organic compound for imparting shape retention to the ceramic powder, and the ceramic powder. And / or forming a molded product using a raw material containing at least clay, and then drying the molded product in the drying and firing step of (2). If a fired product is obtained by firing at a temperature of 800 ° C., and then the obtained fired product is cut into a flat plate having a uniform thickness in the cutting step (3), the cut surface is, for example, a ceramic plate. Can be a smooth surface having a flatness per 120 mm square of 90 μm or less and a centerline average roughness Ra of 1.0 μm or less. As a result, a thin ceramic plate having a smooth surface can be easily obtained. To get a good yield The inventors have found that the intended purpose of the present invention can be achieved, and have reached the present invention. Further, in the molding step (1) described above, if a molded product having a plurality of linear through holes having a single hole size of 0.07 to ⁴ mm ² is formed by an extrusion molding method, It is possible to easily obtain a flat ceramic plate having a uniform thickness, which has a plurality of through-holes, is excellent in air permeability, and allows the fired product to receive heat more uniformly. It has been found that a setter that enables more uniform firing to the fired product is obtained.

That is, according to the study by the present inventors, unlike the conventional method, unlike the case of producing a ceramic plate by firing a molded product formed in a desired shape in advance, the structure of the present invention described above is used. Thus, when it is set as the structure which cut | disconnects the baked product obtained through the formation process and the drying / baking process into the flat plate shape which has uniform thickness, and produces a ceramic board, it does not produce curvature, but is flat. It was found that ceramic plates can be easily produced with good yield. According to the production method of the present invention, a flat ceramic plate having a desired uniform thickness can be easily obtained with a good yield, and in particular, a thickness having a uniform thickness of 5 mm or less, further 2 mm or less. As a method for obtaining a flat ceramic plate having a thin smooth surface. Furthermore, in the molding step, according to the manufacturing method of the present invention for obtaining a molded product having a plurality of fine linear through-holes having a single hole size of 0.07 to ⁴ mm ² , a plurality of through-holes are provided. In spite of being formed, a flat ceramic plate (FIG. 3) having a uniform thickness and a thin thickness of 5 mm or less, further 2 mm or less, as in the case of using a molded product having no through hole. Can be easily obtained.

  A flat ceramic plate having a smooth surface that is thin and satisfies flatness and surface roughness as described above, and has a uniform thickness provided with a plurality of fine through holes in addition to the above. If a flat ceramic plate is used as a setter for holding the material to be fired in a firing furnace used for firing the material to be fired, it is loaded on this regardless of the material and shape of the material to be fired. The object to be fired receives heat uniformly during firing and does not cause uneven firing.

  In particular, when a flat ceramic plate with a small thickness and a uniform thickness with a plurality of fine through-holes is used as a setter, it has better air permeability than one without a through-hole. However, according to the study by the present inventors, it has been found that in addition to this, a more uniform heat treatment is possible. Although the reason for this is not clear, the present inventors have found that the flat ceramic plate having a uniform thickness provided with a plurality of through-holes is in a good state of heat convection in the firing furnace, It is considered that a better fired body that does not cause uneven firing is obtained because the material to be fired receives more uniform heat due to thermal radiation of the ceramic plate.

  On the other hand, the ceramic plate having no through-hole obtained by the method according to the present invention has a smooth surface satisfying the flatness and the surface roughness as described above. If the object is sandwiched and fired, the object to be fired can be fired flat.

  Furthermore, a ceramic plate that enables the formation of various setters capable of performing intensive and uniform firing, etc., on the precise and various forms to be fired as described above, economically, If it can be provided, the productivity of the products obtained in various fields using various parts manufactured using these can be improved, the cost of manufacturing can be reduced, and more economical products can be manufactured. It becomes.

  Hereafter, each process of the method concerning this invention is demonstrated in detail. First, (1) a molding process for forming a molded product using a raw material containing at least a ceramic powder and an organic compound and / or clay for imparting shape retention to the powder will be described. The ceramic powder used as a raw material in the present invention is not particularly limited. For example, alumina, zirconia, silica, magnesia, mullite, cordierite, silicon nitride, silicon carbide, or a composite material containing these as a main component is used. Can be mentioned. These may be used alone or in admixture of two or more materials with an appropriate composition. In this case, when a ceramic plate is used as a setter, the substrate to be loaded is used. Depending on the material and shape of the fired material, the material to be fired does not react with the ceramic plate material, or the material to be fired can be uniformly fired, etc. In such a case, the material may be appropriately selected from the above materials so that the material has sufficient strength.

Among the above, zirconia is particularly useful because it hardly reacts with the electronic device components to be mounted as compared with other materials, and an excellent strength can be obtained even if the thickness is reduced. There are three types of pure zirconia: monoclinic, tetragonal and cubic, but there are phase transition points near 1,100 ° C and 2,370 ° C, and pure zirconia is used. In some cases, cracks may occur due to the volume expansion that occurs during firing. Therefore, it is preferable to use partially stabilized zirconia or stabilized zirconia to which additives such as CaO, MgO, Y ₂ O ₃ are added as zirconia. On the other hand, alumina and silica are cheaper than the above-described zirconia and are particularly effective as materials for obtaining an inexpensive ceramic plate.

  In the present invention, at least an organic compound and / or clay is added to the ceramic powder as described above, and a molded product is formed by mixing a material that imparts shape retention to the ceramic powder. As an organic compound used at this time, a molded product having a desired shape is formed from the ceramic powder obtained in the step (1) by imparting an appropriate shape retaining property to the powder material as mentioned above. In addition, any material may be used as long as it can retain its shape without causing cracks or the like in the subsequent drying step of drying the molded product. Furthermore, it is preferable to use a material that can be easily removed from the molded product in the subsequent firing step of firing the molded product. The addition ratio is preferably about 2 to 10% by mass with respect to the ceramic powder material.

  Specifically, the organic compound that can be used in the present invention has a weight average molecular weight in the range of 400 to 6,000, melts at the time of heating and exhibits an appropriate viscosity, and is heated and fired to obtain a fired product. It is preferable to use an organic compound having such characteristics that it does not remain. This includes polyesters and cellulose derivatives containing many oxygen atoms in the molecule, as well as any amount of ethylene oxide copolymerized with polyethylene oxide, polypropylene oxide, or propylene oxide having an appropriate degree of polymerization. It is preferable to use a polyether. In particular, it is preferable to use a water-soluble cellulose ether which is a derivative of cellulose. Among them, it is preferable to use methylcellulose. Methyl cellulose has heretofore been used as a binder during extrusion molding of fine ceramic products, and can also be suitably used as an organic compound for imparting shape retention to the raw material powder used in the present invention.

  In the present invention, shape retention can be imparted to the ceramic powder by using clay together with the organic compound as described above or alone. Clay is an aggregate of sticky fine particles, mainly hydrous silicate minerals composed of silicon, aluminum, iron, magnesium, and alkali metals, which are highly hydrophilic and plastic when added with water. It is what produces. Specifically, NZ kaolin (made by New Zealand) or the like can be used. When clay is used, since the inorganic components constituting the clay remain after firing, the material purity of the resulting ceramic plate is inferior. However, for example, when manufacturing a ceramic plate used for a general firing tool or the like not intended for precision parts, it is preferable to use clay from the viewpoint of economy and the like. The amount of clay used is preferably, for example, 5 to 20% by mass, although it depends on the type of clay used.

  The shape of the molded product made of the material as described above is not particularly limited, but the same shape can be obtained by a simple cutting operation when it is cut into a flat plate having a uniform thickness in the cutting step to finally form a ceramic plate. In order to be able to form a plurality of ceramic plates, for example, it is preferable to use a columnar molded product having the same cross-sectional shape as shown in FIGS. Furthermore, the cross-sectional shape may be any shape as long as a sufficient loading portion is formed to load the object to be fired when a ceramic plate is formed. Furthermore, when a dedicated stand for mounting a setter made of a ceramic plate is used separately, it may be determined according to the shape of the dedicated stand. The cross-sectional shape may be any shape such as, for example, a circle, an ellipse, a triangle, a square, a polygon such as a pentagon, or the like. Moreover, the columnar molded product having such a cross-sectional shape may be solid (see FIG. 4) or may have a hole (see FIG. 5). Further, the holes are preferably continuous through holes, but may be discontinuous holes.

  There is no particular limitation on the molding method for obtaining a molded product having the shape as described above by using a plastic material with shape retention added to the ceramic powder. It is preferable that the molded material is sufficiently filled without causing cavities so that no defective product is generated when a flat ceramic plate is formed by cutting. For this purpose, it is preferable to form a columnar molded product by, for example, extrusion molding, injection molding or press molding. Among these, it is particularly preferable to form a molded product by extrusion molding.

  A columnar molded product by extrusion molding can be easily obtained by the following procedure, for example. First, an organic compound such as methylcellulose as described above, a substance such as clay, and water as necessary are added to the ceramic powder, and these components are sufficiently mixed and kneaded by an extruder to maintain the ceramic powder. Add shape. A columnar molded product can be easily obtained by extruding the kneaded product thus obtained with an extrusion molding machine through a die. Moreover, if the shape of the die to be used is appropriately selected, a molded product having a desired cross-sectional shape such as a circle, an ellipse, or various squares can be easily obtained. For the extrusion molding, for example, a vacuum extrusion molding machine manufactured by Takahama Industry Co., Ltd. can be used. FIG. 4 is a perspective view showing an example of a columnar molded product obtained as described above.

Furthermore, for example, as a setter, a flat ceramic plate having a uniform thickness and having a plurality of through holes of a desired shape, which is excellent in properties such as air permeability, is a straight through hole having an opening of a desired shape. It can be obtained from a molded product having a plurality of holes. For the above-described purpose, it is particularly preferable to form a molded product having a plurality of linear through holes in which the size of one hole is 0.07 to ⁴ mm ² (see FIG. 5). Such a molded product can be easily obtained by extrusion molding using a die. At this time, the size of the opening of one hole and the location to be provided may be determined according to the shape of the object to be fired. When the object to be fired is very small, for example, the size of the opening of one hole may be set to 1 mm ² or less. In order to obtain a ceramic plate that can also be applied to a minute object to be fired, it is necessary to obtain a molded article in which finer through holes are provided over the entire surface in the cross-sectional direction. According to the method of the present invention for forming a molded article provided with linear through holes by using, for example, a minute hole having an opening of one hole of 0.25 mm square is provided over the entire surface. Further, it is possible to form a ceramic plate having excellent air permeability and sufficient strength. Of course, the shape of the through hole is not limited, and may have an opening having a desired shape such as a circle, an ellipse, or a polygon such as a square. In addition, the opening shapes of the plurality of through holes may be the same as shown in FIG. 5 or when the ceramic plate is cut and formed, for example, the opening diameters of the central hole and the peripheral opening are different. For example, it may be non-uniform. FIG. 5A is a perspective view of a block-shaped molded product, and FIG. 5B is an enlarged plan view of a circled portion of FIG. 5A. 3 in FIG. 5 shows a linear through-hole.

  As described above, if a die to be used at the time of extrusion molding is appropriately selected, for example, not only a solid molded product but also linear through holes having substantially the same opening shape are formed entirely or Partially, regularly or irregularly shaped products, or linear through holes with two or more different aperture shapes, lined up in whole or in part, regularly or irregularly A molded product can be obtained easily. For this reason, according to the manufacturing method of the present invention, it is possible to easily obtain various flat ceramic plates that are useful as setters having the optimum shape for a variety of objects to be fired. When the shape of the molded product is a setter, holes can be provided on almost the entire surface of the part on which the object to be fired is loaded, or in particular, the holes can be provided over substantially the entire surface. It is excellent in air permeability, and when fired, organic substances such as a binder contained in the fired product can be removed with a high removal rate. In addition, as described above, more uniform heat treatment can be performed on the object to be fired.

  Next, after drying the molded product obtained as described above, the dried molded product is fired at a temperature of 1,300 to 1,800 ° C. to obtain a fired product. explain. In this step, the molded product obtained as described above is dried, and the drying temperature is, for example, preferably 30 to 120 ° C, more preferably about 50 to 100 ° C. For this reason, it is preferable that the molded product obtained in the molding step (1) described above has a shape that can be satisfactorily dried. The molded article having a plurality of through holes as described above is advantageous in this respect because it can be dried more rapidly than the solid one in the drying step. Next, in the present invention, the molded product thus dried is fired at 1,300 to 1,800 ° C. The time for drying and firing may be appropriately selected according to various ceramic materials used as the material of the molded product, additives such as organic compounds and clay, the size of the molded product, and the like. In the present invention, for example, the drying time may be about 5 to 12 hours, and the baking time may be about 60 hours.

  Next, the cutting step (3) for cutting the fired product obtained above into a flat plate having a uniform thickness will be described. According to the study by the present inventors, the fired product obtained above can be cut as shown in FIGS. 4 and 5 using a cutting machine such as an inner circumference slicer, a multi-wire saw, a band saw or the like. Many flat ceramic plates having a uniform thickness can be easily obtained. Further, by cutting using the above-described cutting apparatus, the cut surface has, for example, a flatness per 120 mm square of the ceramic plate of 90 μm or less and a center line average roughness Ra of 1.0 μm or less. It can be made smooth. Among the above, for example, the inner circumference slicer and the multi-wire saw are used for precision cutting when a silicon wafer is cut out from an ingot, and when applied to the present invention, in particular, for firing a precise workpiece. It is possible to easily produce a thin flat ceramic plate that is useful as a setter.

  That is, as shown in FIGS. 4 and 5, using the cutting machine as described above, the block-like fired product 2 is cut at the position indicated by the broken line indicated by 5 so as to have a uniform thickness. A large number of flat ceramic plates 1 having an arbitrary thickness can be easily manufactured with a high yield. As shown in FIG. 4, the ceramic plates 1 having different thicknesses can be simultaneously manufactured by appropriately changing the position 5 for cutting one fired product 2.

  In the cutting step, the thickness when cutting the fired product can be set appropriately according to the material to be fired to be placed on or sandwiched by the ceramic plate. In particular, according to the method of the present invention, the thickness Is a thin plate-like ceramic plate having a uniform thickness of 5 mm or less. According to the present invention, even an extremely thin thin plate-like ceramic plate having a uniform thickness of 2 mm or less, further 0.2 mm or less, for example, can be easily manufactured with a high yield. Although these thin ceramic plates are very thin, they satisfy a sufficient strength as a setter or a clamping member, and have a good smooth surface and a flat surface having a plurality of through holes. A flat ceramic plate can be easily produced.

  The ceramic plate having a uniform thickness obtained by cutting the fired product into a flat plate shape as described above, unlike a conventional ceramic plate obtained by firing a flat plate-shaped product, does not cause warping, It has a flat surface. Moreover, if a solid molded product is used, a ceramic plate having a good smooth surface without unevenness can be obtained.

  Furthermore, in the manufacturing method according to the present invention, the ceramic plate obtained by cutting in the cutting step can be used as it is for a setter or the like, but a polishing step may be further provided to polish a desired portion of the ceramic plate.

  The ceramic plate obtained by the method according to the present invention is a flat plate having a uniform thickness. However, when used as a setter, the ceramic plate is used as it is as shown in FIG. Alternatively, it may be a flat plate with a convex portion in which a convex member having an arbitrary shape functioning as a spacer is bonded to at least one surface of the flat plate (see FIG. 2). In this way, since setters can be used in a stacked manner, firing of electronic device components can be performed intensively.

  The ceramic plate obtained by the production method according to the present invention is a flat plate having a uniform thickness, has a smooth surface, and in that state, has a plurality of through holes and has good air permeability. Therefore, as described above, it can be used as a setter as it is, but it can be made a very useful setter by applying some processing as described below. For example, a setter as shown in FIG. That is, such a setter is convex in the vicinity of the outer periphery of the flat surface of the ceramic plate 1 made of a flat plate having a uniform thickness and may have a plurality of linear through holes. Are formed, and at least three portions of the edge are provided with convex portions 7 higher than the height of other portions of the edge, and the highest positions of the convex portions at least three portions are provided. , Having a structure having substantially the same height.

  If the shape of the setter is set in this way, when the object to be fired is placed on the flat surface part, even if the object to be fired is, for example, cylindrical or spherical, the outer peripheral part of the flat surface. Since there are the convex edges 6 provided continuously, it is possible to effectively prevent these non-stable to-be-fired objects from falling from the setter in a process such as firing. Further, in the illustrated example, the convex portions 7 higher than the height of the other portions of the edge are provided at the four positions of the edge 6, so that a plurality of setters are stacked as shown in FIG. be able to. Furthermore, especially in the case of the form of using repeatedly, as shown in FIGS. 6 (A) and (C), the ceramic plate 1 is provided with a plurality of through holes provided on the flat surface described above. It is preferable to use it. In this way, even when used repeatedly as shown in FIG. 6C, excellent air permeability can be ensured, so even firing can be performed even in this state.

  Moreover, as another setter according to the present invention, a flat surface of a ceramic plate made of a flat plate having a uniform thickness and having a plurality of straight through-holes as shown in FIG. An example is a setter in which a continuous edge of substantially the same height is provided in the vicinity of the outer periphery in a convex shape in a direction perpendicular to the flat surface. Similarly to the above, the setter of this form is also a convex shape having substantially the same height continuously provided on the outer peripheral portion of the flat surface even if the object to be fired is cylindrical or spherical. Therefore, it is possible to effectively prevent these non-stable to-be-fired objects from falling on the setter in a process such as firing. Furthermore, as will be described later, there is also an advantage that molding is easier than that in which the convex portion 7 is formed on a part of the edge 6 described above.

  The setter in the form in which a plurality of through-holes are provided on the flat surface shown in FIG. 6A can be easily formed as follows. This will be described with reference to FIG. According to the method for manufacturing a ceramic plate according to the present invention, a ceramic plate having a smooth surface can be easily obtained. Therefore, as shown in FIG. 7C, the edge 6 having the convex portion 7 is formed in advance, and the ceramic plate 1 obtained by the method according to the present invention is bonded thereto by a conventional method. Easy to get.

  The edge 6 having the protrusion 7 is formed by a known method of pouring a ceramic material into a mold and then firing it, as shown in FIGS. 7B and 7C. 6 can be obtained (hereinafter referred to as frame-shaped portion 8). However, in this method, depending on the form of the frame-shaped portion 8, it may be difficult to perform die cutting. On the other hand, according to the method shown in FIG. 7, a setter can be obtained with a high yield even in such a case. First, a flat surface and a frame-shaped portion 8 are formed by a known method as described above (see FIG. 7A). Next, the flat surface portion is cut off with an apparatus such as a surface grinder (see FIG. 7B). The frame-like portion 8 obtained in this way has a smooth surface at the cut portion. Finally, the smooth surface of the frame-shaped portion 8 is bonded by a known method to a position that becomes the upper surface of the ceramic plate 1 in which the through holes obtained by the method according to the present invention are provided over the entire surface (see FIG. 7 (C) and (D)). At this time, since the cut surfaces of the ceramic plate 1 and the frame-shaped portion 8 are both smooth surfaces, the bonding can be easily performed, and the height of the convex portion 7 is easily substantially increased in the bonded state. Are identical. As a result, when the setters are stacked and used as shown in FIG. 6C, the setters can be stacked stably.

  As shown in FIG. 8 described above, substantially the same height is formed in the vicinity of the outer periphery of the flat surface of the ceramic plate obtained by the method according to the present invention so as to protrude perpendicularly to the flat surface. The setter provided with the continuous edge 9 can be easily obtained by the following method. With reference to FIG. 8, an example in which a square ceramic plate is used will be described. First, four ceramic prisms to be the edges 9 are formed (see FIG. 8A). Next, the prisms are sequentially bonded to the upper surface of the ceramic plate 1 provided with the through holes obtained by the method according to the present invention using an inorganic slurry (see FIGS. 8B and 8C). Thereafter, by firing this, a setter provided with continuous edges 9 of substantially the same height formed in a convex shape in a direction perpendicular to the flat surface as shown in FIG. can get. The height or width of the edge 9 provided at this time may be appropriately determined according to the object to be fired, and may be as shown in FIG. According to the method described above shown in FIG. 8, a setter having an edge formed in a convex shape in a direction perpendicular to a flat surface is easier than the method of forming the frame-shaped portion 8 shown in FIG. Obtainable.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.
<Example 1>
In this example, alumina powder having an average particle size of 0.5 μm and a purity of 99% by mass was used as the forming material. Further, in order to impart shape retention to the alumina powder, methylcellulose is contained in the alumina powder in a proportion of 5% by mass and mixed and kneaded by an extrusion molding machine (manufactured by Takahama Kogyo Co., Ltd.). A kneaded product having shape retention was obtained. Subsequently, a solid prismatic shaped product having a size of 133 × 133 × 100 mm made of the kneaded material was formed by the above-described extruder.

  Next, after drying the obtained molding at 100 ° C. for 10 hours, the temperature was raised to 1,550 ° C. under the condition of 60 ° C./hour, and firing was performed at that temperature for 120 minutes. The alumina fired product obtained above was a solid prismatic shape of 120 × 120 × 90 mm. Next, the alumina fired product obtained above was horizontally cut with an inner circumference slicer (manufactured by Tokyo Seimitsu Co., Ltd.) so that each thickness was uniformly 3 mm. As a result, 25 square-plate alumina ceramic plates having a uniform thickness of 120 × 120 × 3 mm were obtained.

  The cut surfaces of the square plate-like ceramic plate obtained above were both very flat and smooth according to the visual and tactile sensations. Therefore, five of the obtained flat ceramic plates were sampled, and the flatness of the cut surfaces of each ceramic plate was guaranteed by NIST (US Metrology Organization), and the surface roughness was based on JIS method. It was measured by the method. Specifically, the flatness was measured on a 120 × 120 mm surface, which is a cut surface, using TROPEL FlatRule 200 (manufactured by TROPEL). As a result, the flatness of any ceramic plate was 40 to 64 μm. Moreover, about the same cut surface which measured this flatness, centerline average roughness Ra was measured using the contact-type surface roughness meter by Taylor Hobson (TAYLOR HOBSON) company. As a result, Ra was 0.63 to 0.65 μm. Also from the measurement results, the flat ceramic plate obtained by thinly cutting the fired product with a uniform thickness has a flat cut surface and a uniform smooth surface with suppressed irregularities. I was able to confirm.

  Using the ceramic plate produced as described above as a setter, 25 pieces of barium titanate-based ceramic compacts (hereinafter referred to as barium titanate-based parts) having a size of about 10 mmφ are mounted on the ceramic plate. The temperature was raised to 600 ° C. and heat treatment was performed. The temperature raising condition for the heat treatment was 30 ° C./hour. When the barium titanate parts after the treatment were examined, no burning unevenness was observed in all.

<Example 2>
In the same procedure as in Example 1, except that 0.5% by mass of titanium oxide was added as a sintering aid to the material of the molded product used in Example 1, and the size of the molded product was changed. A fired product having an area smaller than that of Example 1 of 30 × 30 × 50 mm was obtained. Then, in the cutting step, the obtained fired products are cut with an inner slicer (manufactured by Tokyo Seimitsu Co., Ltd.) so that each has a uniform thickness of 0.2 mm, and 30 × 30 × 70 sheets of a ceramic plate made of alumina having a square plate shape, which is very thin and 0.2 mm, stronger than that obtained in Example 1, was obtained. About the obtained ceramic board, it carried out similarly to Example 1, and measured flatness and surface roughness about the cut surface of the ceramic board. As a result, the flatness showed a good value corresponding to the area of the ceramic plate. There was no difference in surface roughness. Further, when used as a setter, it was as good as in Example 1.

<Example 3>
Instead of the alumina powder used in Example 1, 8 mol Y ₂ O ₃ stabilized zirconia powder having an average particle size of 0.5 μm was used, and the size of the molded product was changed, and the same as in Example 1 In the procedure, a fired product having an area smaller than that of Example 1 of 30 × 30 × 50 mm was obtained. Then, in the cutting step, the obtained fired products are cut with an inner slicer (manufactured by Tokyo Seimitsu Co., Ltd.) so that each has a uniform thickness of 0.2 mm, and 30 × 30 × 70 sheets of zirconia ceramic plates made of zirconia, which are very thin and 0.2 mm thicker than those obtained in Example 1, were obtained. About the obtained ceramic board, it carried out similarly to Example 1, and measured flatness and surface roughness about the cut surface of the ceramic board. As a result, the flatness and the surface roughness were the same as in Example 2. Further, when used as a setter, it was as good as in Example 1.

<Example 4>
Of the ceramic plates obtained in Example 1, the five ceramic plates whose flatness was measured were further polished using a 4-way double-sided lapping polisher to polish the smooth surface obtained by this embodiment. An example ceramic plate was obtained. About the obtained ceramic board, it carried out similarly to Example 1, and measured the flatness and surface roughness of the cut surface (polishing surface) of a ceramic board. As a result, the flatness of any ceramic plate was 3.0 to 4.5 μm, and it was confirmed that the cut surface could be made flatter by polishing the surface. On the other hand, the center line average roughness Ra is 0.90 to 0.95 μm, and the ceramic plate of this example is more uneven than the ceramic plate of Example 1 in a state of being cut without being polished. Slightly inferior.

  A plurality of ceramic plates obtained in this example were used, and an object to be fired was sandwiched between the ceramic plates, and a firing process was performed under the same conditions as in the past. It was confirmed that smooth surfaces were respectively formed on the surfaces of the plurality of products obtained after firing. When the flatness was measured for the smooth surface of each product, it was confirmed that the flatness was comparable to that of the ceramic plate used.

<Example 5>
By using the kneaded material made of the material used in Example 1 and changing the die to be used in the same extrusion molding machine as that used in Example 1, a molded product having a shape different from that in Example 1 was obtained. That is, the molded product has a prismatic shape with a size of 133 × 133 × 100 mm as in Example 1, but the opening is 0.55 × 0.55 mm as shown in FIG. This is a block shape in which a plurality of linear through holes are provided over the entire surface (see FIG. 5A). The obtained molded product was dried and fired to obtain a fired product. Thereafter, the fired product was cut with an inner slicer (manufactured by Tokyo Seimitsu Co., Ltd.) so as to have a uniform thickness of 3 mm to obtain a plurality of ceramic plates having the same shape. In the obtained ceramic plate, through-holes each having a square shape of 0.5 × 0.5 mm as shown in FIG. 5B are regularly provided over the entire surface. is there.

  The ceramic plate obtained as described above had a plurality of through-holes, but both were very flat according to visual and tactile sensations. Therefore, when the flatness and the surface roughness of the cut surface where no through hole was formed were measured using the same apparatus as in Example 1, these portions were flat and had good smoothness without irregularities. It was confirmed that it was a surface.

  Further, the barium titanate-based component was heat-treated in the same manner as in Example 1 except that the ceramic plate having a plurality of through holes obtained in this example was used as a setter. When the processed parts were examined, no burning unevenness was found in all of them. Furthermore, when sampling was performed from each part after the heat treatment and the removal rate of the organic substances contained in the part was examined, it was confirmed that a high removal rate was achieved in any case.

<Example 6>
Instead of methylcellulose used in Example 1, NZ kaolin (made in New Zealand) was contained in alumina powder at a ratio of 10% by mass in the same procedure as in Example 1 and the same shape as in Example 1. A ceramic board was obtained. When the flatness and surface roughness of the obtained ceramic plate were measured in the same manner as in Example 1 for the cut surface of the ceramic plate, the flatness and surface roughness were as good as those in Example 1. It was. Further, when used as a setter, it was as good as in Example 1.

<Comparative Example 1>
Using a plastic kneaded material made of the material used in Example 1, a square plate-like molded product having a size of 133 × 133 × 3.3 mm was obtained. Next, the molded product obtained was dried at 100 ° C. for 10 hours, then heated to 1,550 ° C. at 60 ° C./hour, and baked at that temperature for 120 minutes, so that the size was 120 × 120 × 3 mm. A square plate-like alumina ceramic plate was obtained.

  When the ceramic plate obtained above was observed visually and by touch, a clear warp was observed, and the surface was not flat. Therefore, when the flatness of the surface of the ceramic plate was measured in the same manner as in Example 1, the flatness was 640 to 680 μm, which was larger than that of the ceramic plate of the example, and the flatness was greatly inferior. Met. Further, in order to flatten, it is necessary to perform a polishing process.

  Using a plurality of the ceramic plates of Comparative Example 1 produced as described above, a fired product was sandwiched between the ceramic plates in the same manner as in Example 4 to perform a firing process. The flatness of the surface of the plurality of products obtained after firing was almost the same as the ceramic plate used, and a good product could not be obtained.

<Example 7>
A setter was formed as follows using a ceramic plate in which the minute through holes obtained in Example 5 were regularly provided over the entire surface. First, a flat surface and a frame-shaped portion 8 are formed by a known method (see FIG. 7A). Next, the flat surface portion is cut off with a surface grinder (manufactured by Nikko Kikai Co., Ltd.) (see FIG. 7B). The obtained frame-like portion 8 was a flat smooth surface at the cut portion. Finally, the ceramic plate 1 having a through hole and the smooth surface of the frame-shaped portion 8 obtained above were bonded by the following method (see FIGS. 7C and 7D).

The ceramic plate 1 and the frame-shaped portion 8 are bonded using an inorganic slurry having the following composition, and the ceramic plate 1 and the frame-shaped portion 8 are integrally formed by heating to 1,500 ° C. and heating. The setter of the present Example provided in this was obtained.
・ Alumina 60%
・ Methylcellulose (binder) 8%
・ Resin dispersant 1%
・ Water 31%

  At this time, since the cut surfaces of the ceramic plate 1 and the frame-shaped portion 8 are both flat surfaces, the bonding could be easily performed. Moreover, it has confirmed that the height of the four convex parts 7 of the obtained setter was the same in the state which completed adhesion | attachment. Furthermore, when the obtained setters were stacked in eight stages in the state shown in FIG. 6C, it was confirmed that each setter overlapped in a stable state without rattling. Moreover, when it used for baking of a cylindrical to-be-fired thing, the to-be-fired thing did not fall, but when the sintered body after a process was investigated, baking unevenness was not seen in all.

<Example 8>
In Example 6, instead of the frame-shaped portion 8, four prisms made of ceramics having the same shape of 10 × 5 × 120 mm were used, and these four prisms were made of the same inorganic slurry as used in Example 6. Was bonded to the outer periphery of the ceramic plate 1 as shown in FIG. This is heated to 1,500 ° C. and subjected to heat treatment, and the ceramic plate 1 and the prism are integrally provided, and are formed in a convex shape in a direction perpendicular to the flat surface. A setter of this example in which continuous edges 9 were formed was obtained. It was confirmed that the setter of this example also overlaps in a stable state. Moreover, when it used for baking of a cylindrical to-be-fired thing, the to-be-fired thing did not fall, but when the sintered body after a process was investigated, baking unevenness was not seen in all.

  As described above, according to the present invention, when a ceramic plate is used as a setter, a uniform firing process without uneven baking is possible for the stacked objects to be fired, When the object to be fired is sandwiched between ceramic plates and used for firing, it has a sufficient strength that can be flatly fired, has no warp in the manufacturing stage, and has a good smooth surface. In addition, there is provided a method for producing a ceramic plate that can easily and economically obtain setters having various shapes suitable for various objects to be fired.

It is a typical perspective view of an example of the ceramic board obtained by the method concerning the present invention. It is a typical perspective view of another example of the ceramic board obtained by the method concerning this invention. It is a typical perspective view of another example of the ceramic board obtained by the method concerning this invention. It is a figure for demonstrating the baked product used by this invention. It is a figure for demonstrating another baking products used by this invention. It is an example of the setter concerning this invention. It is explanatory drawing of the method of manufacturing the setter shown in FIG. It is explanatory drawing of the setter of another form concerning this invention, and the method of manufacturing this setter.

Explanation of symbols

1: Ceramic plate 2: Firing product 3: Through hole 4: Protruding member 5: Line 6 to be cut, 9: Edge 7: Convex portion 8: Frame-like portion

Claims (10)

  A molding step of forming a molded product using a raw material containing at least a ceramic powder and an organic compound and / or clay for imparting shape retention to the powder, and drying the molded product after drying the molded product A drying / firing step of firing the product at a temperature of 1,300 to 1,800 ° C., and a cutting step of cutting the fired product obtained above into a flat plate having a uniform thickness. A method for producing a ceramic plate.   In the cutting step, the cut surface of the fired product is cut so as to be a smooth surface having a flatness per 120 mm square of a ceramic plate of 90 µm or less and a center line average roughness Ra of 1.0 µm or less. A method for producing a ceramic plate according to 1. ^2. The production of a ceramic plate according to claim 1, wherein, in the forming step, a formed product having a plurality of linear through holes in which the size of the opening of one hole is 0.07 to ⁴ mm ² is formed by an extrusion forming method. Method.   The manufacturing method of the ceramic board of any one of Claims 1-3 cut | disconnected so that thickness may become 5 mm or less in a cutting process.   The method for manufacturing a ceramic plate according to any one of claims 1 to 4, wherein in the cutting step, cutting is performed using any one of an inner circumferential slicer, a wire saw, and a band saw.   The method for producing a ceramic plate according to any one of claims 1 to 5, further comprising a polishing step of polishing at least a part of the surface of the ceramic plate after the cutting step.   A ceramic plate obtained by the method for producing a ceramic plate according to any one of claims 1 to 6.   A ceramic setter for holding an object to be fired in a firing furnace, wherein the ceramic plate according to claim 7 is used for a part or all of the setter.   A continuous edge formed in a convex shape in a direction perpendicular to the flat surface in the vicinity of the outer periphery of the flat surface of the ceramic plate made of a flat plate having a uniform thickness and may have a plurality of straight through holes. And at least three portions of the edge are provided with projections higher than the height of the other portions of the edge, and the highest positions of at least three projections have substantially the same height. The ceramic setter according to claim 8.   It is formed substantially in the vicinity of the outer periphery of the flat surface of the ceramic plate made of a flat plate having a uniform thickness and may have a plurality of linear through holes, and is formed in a convex shape in a direction perpendicular to the flat surface. The ceramic setter according to claim 8, wherein continuous edges having the same height are provided.

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