JPH09278517A - Setter for baking and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a setter for baking having high heat-resistance, arising little trouble of the adhesion of the baked material and the setter and enabling easy recovery of the baked material and to provide a process for the production of the setter. SOLUTION: This setter for baking has recesses or protrusions each having a diameter of 0.05-3mm on one or both surfaces of the setter. The setter is made of ceramics such as alumina, silica, magnesia, mullite, zirconia or cordierite or a composite material containing the ceramics as main components. The setter can be produced by using small particles having spherical or indefinite shape, a tape or sheet carrying the small particles bonded to its surface or a resin sheet having recesses on the surface by machining, thermal processing, pressing or molding, depressing the surface of a molded article or forming protrusions on the surface by pressing, tape-forming or casting and baking the product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a setter used for firing electronic material parts and the like.

[0002]

2. Description of the Related Art Multilayer capacitors, ceramic capacitors including high voltage capacitors, piezoelectric materials such as piezoelectric ceramics, microwave dielectrics, multilayer LC composite chips, S
High frequency components such as AW filters, semiconductor capacitors, P
Barium titanate (BaTiO ₃ ), lead zirconate titanate (PbZrTiO ₃ ), strontium titanate (SrTiO ₃ ), zinc oxide (ZnO), as a raw material for semiconductor ceramics such as TC thermistor, NTC thermistor, ceramic varistor, and ceramic sensor. Zirconium oxide (ZrO ₂ ), rare earth oxides, oxides such as glass materials, or composites thereof are used.

Such electronic components are generally prepared by mixing these raw materials, molding them, and placing them on a setter for firing.
By firing at ˜1400 ° C., a ceramic body is formed, and electrodes are formed on this body to form an element, which is finally assembled into a component.

[0004]

When firing electronic material parts such as these various capacitors and sensors, in general,
Inexpensive and lightweight oxide-based setters such as alumina and mullite are used. However, Ba of BaTiO ₃ and Pb of PbTiO ₃ which are the main raw materials of the capacitor react with alumina and are contaminated, and electrical characteristics are deteriorated, and a fired product containing a large amount of glass components is fired near the melting temperature of glass. In this case, there was a problem that the glass component was melted and the setter and the fired product adhered to each other.

Therefore, in order to prevent reaction between the setter and the fired product or adhesion of the setter, a method is used in which ceramic powder that does not react with the fired product is spread on the setter as spread powder and fired. However, even in this method, since the ceramic powder adheres to the surface of the fired product, when the removal work of the powder occurs or the firing temperature rises, the powders agglomerate or adhere to each other. It is difficult to use and needs to be treated as industrial waste. There is also a porous setter, but the thinner it is, the weaker it is in strength, and there is a problem such as chipping of the setter.

Recently, miniaturization and weight reduction of AV equipment, OA equipment, home electric appliances, etc., in which capacitors and the like are frequently used, are required, and electronic material parts are also miniaturized. Contamination of the fired product due to the contact between the two and the generation of defective products due to the adhesion between the fired product and the setter are important problems including the treatment of industrial waste.

As a method of solving these problems, the surface of the firing setter is coated with a zirconia-based slurry that does not react with the fired product, a zirconia-based thermal spray material is coated, or a zirconia-based ceramic is used for firing. It is being considered to manufacture a setter for a vehicle.
However, although the use of zirconia eliminates the problem of preventing contamination, coating has the problems of high coating cost and cracking and peeling of the coating layer due to the difference in thermal expansion coefficient from the setter material. On the other hand, also in the zirconia setter, since the density is high and the thermal conductivity is low, a temperature difference occurs on the setter, uneven burning occurs in the fired product, or the contact surface with the fired product is a smooth surface, so the firing is performed. When the temperature rises, there is a problem of adhesion between the setter and the baked product. Therefore, it is necessary to take measures to reduce productivity, such as slowing down the temperature rising rate.

Further, a method of laying zirconia sintered spheres as spread powder on a setter and firing, or a method of adhering the sintered spheres to the setter is effective.
If the size of the sintered sphere that becomes the spread powder is larger than that of the fired product, it takes time to collect the fired product, and in the case of the spread powder, if the setter is not concave, the spread powder spills or the sintered sphere is bonded. When the adhesive strength is weak, repeated use causes the sintered spheres to separate from the setter, and when the fired product is large, the surface of the fired product that comes into contact with the setter has traces of spread powder or adhesives, resulting in surface polishing. Problems such as the need for finishing are occurring.

In the present invention, these problems are solved, the heat resistance is good, and since the setter surface is dented or formed with protrusions, the fired product and the setter are close to point contact,
Even if the firing temperature rises, the fired product and the setter do not easily adhere to each other, and since there are no adherents such as sintered spheres on the surface of the setter, there is no contamination of foreign matter even after repeated use, and the fired product can be easily collected. It is an object of the present invention to provide a firing setter and a manufacturing method thereof.

[0010]

The present invention is characterized in that one or both sides of a setter are formed with depressions or protrusions each having a diameter in the range of more than 0.05 mm and less than 3 mm. The purpose is to setter for firing.

The requirements to be satisfied by the firing setter of the present invention will be described in detail below.

(A) Setter Material As the material for the setter, there are ceramics such as alumina, silica, mullite, magnesia, zirconia, cordierite, silicon nitride and silicon carbide, or composite materials containing these as the main components. There is no particular limitation on the material for forming the depression or the protrusion on the surface. In the case of zirconia, the density is higher and the thermal conductivity is lower than that of other materials, so that a temperature difference occurs on the setter depending on the firing conditions, and uneven firing occurs in the fired product. For this reason, it has been necessary to take measures to reduce productivity, such as slowing down the temperature rising rate, but this phenomenon can be considerably alleviated by forming depressions or protrusions on the surface of the setter.

(B) Shape of fine particles The shape of the fine particles for forming depressions on the surface of the molded body for a setter is not particularly limited, but in the case of forming protrusions on the surface, a shape closer to a spherical shape is preferred. preferable. In particular, when the smoothness of the setter surface is required, the sphericity obtained by dividing the minimum diameter of the fine particles by the longest diameter is 0.6 or more, 80% or more, and more preferably 0. 80% or more is preferable for 8 or more. Even if a depression is formed, if the shape is bad, it will adhere to tape with adhesive such as adhesive tape or a thin film sheet, and when used for press molding, the tape or sheet will have unevenness, and the thickness of the setter will be reused. There may be a difference in.

(C) Material of fine particles As fine particles capable of forming depressions or projections on the surface of the setter molding, metal-based iron-based materials such as carbon steel, stainless steel, cast iron, zinc, aluminum, There are non-ferrous materials such as copper, and non-metallic materials include glass such as soda lime, alumina, zirconia, zircon, silicon carbide,
There are ceramics such as mullite, thermoplastic resins such as polyethylene and nylon, and thermosetting resins such as urea, melamine and ferrule. Others, carbon,
Chips such as ice and wood, crushed plants such as corn, nuts and walnuts can also be used. There is no particular limitation on the material of the fine particles for forming the projections on the surface of the setter to process the sheet, but when directly contacting the surface of the molded body to form a depression, the problem of surface contamination due to rust etc. Therefore, it is preferable to use a non-metal type.

(D) Size and distribution of fine particles The size of the fine particles depends on the size of depressions or protrusions after firing.
The diameter of each piece may be selected in consideration of the shrinkage rate of the molded body so that the diameter is in the range of more than 0.05 mm and less than 3 mm. It must be less than half the maximum face length. If it is larger than this value, the effect of point contact between the fired product and the setter is reduced. When the area where the fired product contacts the setter is large or when the weight of the fired product is heavy, if there is a protrusion on the surface of the setter, the surface where the fired product contacts the setter after firing tends to leave marks of depressions, Since a finish such as polishing may be required, the setter surface preferably has a depressed shape.

On the other hand, it is better to use fine particles having a smaller particle size.
There is an effect of point contact with the fired product, but if it is too small, the depression of the upper surface of the setter or the protrusion becomes close to a flat surface, so that the effect of point contact is lost. Especially 0.05m
Since the surface of a setter having depressions or projections with fine particles smaller than m has a smoothness comparable to that of a flat surface, there is a possibility that the fired product and the setter adhere to each other as the firing temperature increases.

Regarding the distribution of the fine particles, it is preferable that the particles are classified and sorted with a sieve having a selected mesh in consideration of the shrinkage ratio of the molded product after firing. As for the classification range, the value obtained by dividing the lower limit value of the opening of the sieve by the upper limit value is preferably 0.69 or more. Below this value, when forming a projection on the surface of the setter, the height of the surface in contact with the fired product is different, and the effect of point contact is reduced.

(E) Method of forming depressions or protrusions When forming depressions or protrusions on the surface of a molded article, spherical or irregularly shaped fine particles, tape or sheet to which these fine particles are adhered, machine, heat, press Depending on the processing method such as
It is possible to use a resin sheet or the like having a depression formed on the surface. Using these, a molded body is manufactured by a molding method such as press molding in which powder is molded using a mold, casting molding in which slurry is poured into a mold, tape molding in which slurry is poured onto a sheet, but the molding method is particularly limited. No need.
Since the characteristics differ depending on the powder manufacturing method, it is necessary to select a molding method suitable for the characteristics of the powder as the raw material. In the case of dry press molding, if the thickness of the setter is thin, it will be damaged during handling, so it is preferable to use powder to which a binder such as an acrylic binder is added.

When the fine particles are used as they are, the fine particles are laid in a mold, slurry or kneaded clay is poured over the mold, and after drying, the mold is removed from the mold to obtain a compact having a depression formed on the surface. The fine particles on the surface of the molded body may be removed as they are by firing or the like, but those that are melted by firing and adhere to the setter need to be removed.

When using fine particles adhered to an adhesive tape such as an adhesive tape or a thin film sheet,
The sheet is adhered to the mold, and the slurry or kneaded clay is poured over it, and after drying, it is removed from the mold to obtain a molded product having a depression formed on the surface, or put powder in the mold,
Make a low-pressure molded body, remove the upper punch of the mold, place the surface of the sheet to which the microparticles are adhered with the microparticles facing toward the molded body, insert the upper punch again, and press the surface to collapse the surface. A molded body in which is formed is obtained. Even if fine particles are attached to the upper punch of the mold with double-sided tape, etc., it is possible to obtain a molded product with depressions formed on the surface. However, when the molded product becomes thinner, a mold release agent is applied. However, the molded body adheres to the mold and does not come off, which is not preferable. The material of the adhesive-attached tape or the thin film sheet is preferably cloth adhesive tape or resin tape. A thin metal plate made of metal such as stainless steel is not preferable because it is difficult to reuse when deformed and the releasability of the molded body is not good. The thickness is preferably 2 mm or less, more preferably 1 mm or less. If it is thicker than 2 mm,
The mold releasability of the molded product deteriorates.

When a depression is formed on the surface of the resin sheet by a processing method such as mechanical, heat, or press, machining cost is high, so if precision is not required, it is necessary to make a small amount in the mold. Grain is put and resin sheet is adhered to the upper and lower punches with double-sided tape etc., then 100kg / cm ²
It is inexpensive and preferable to pressurize with the above pressure to make an indentation, or to heat fine particles and press a resin sheet adhered to an upper punch or a lower punch with a double-sided tape to make an indentation.

As the material of the resin sheet, thermoplastic resins such as polyethylene and nylon, urea, melamine,
There is a thermosetting resin such as a ferrule, but it is not particularly limited, and an inexpensive and easy-to-process one is preferable. Further, the thickness is preferably 5 mm or less, and when the fine particles are used to make an indentation by heat or press working, the thickness is preferably larger than the maximum radius of the fine particles. If it is thicker than 5 mm, the pressure will be absorbed,
The molded product may have a defective shape.

When a resin sheet having depressions formed on the surface obtained by such a method is used to obtain a molded article having projections formed on the surface, the sheet is adhered in a mold and the slurry is applied thereon. Pour the clay and kneaded material, and after drying, remove from the mold,
Obtain a molded product with protrusions on the surface, or put powder in a mold to make a low-pressure molded product, remove the upper punch of the mold, and place the resin sheet's depressed surface toward the molded product. Then, the upper punch is again put in and pressure is applied to obtain a molded body. If the molded body is thick, powder may be put in a mold without passing through the low-pressure molded body, placed on a resin sheet, and pressed, but if the molded body has a thickness of 3 mm or less, molding is performed. It is not preferable because the accuracy of the body thickness is lost.

In any case, the fine particles, the tape or sheet to which the fine particles are adhered, the resin sheet having the depressions formed on the surface by a processing method such as mechanical, heat, press, and molding should be reused. Even in press molding with high production efficiency, it is not necessary to form unevenness on the surface of the mold, and it is possible to inexpensively and easily manufacture a setter having depressions or projections of any size.

A method for manufacturing a zirconia-based setter, which is an example of the firing setter of the present invention, will be described below.

The zirconia powder used for the zirconia-based setter is manufactured by electrofusion method, hydrolysis method, neutralization coprecipitation method,
The hydrolysis-neutralization method, the hydrothermal oxidation method, the thermal decomposition method, the alkoxide method, and the like can be used, but they are not particularly limited. Further, rare earth oxides such as MgO, CaO, Y ₂ O ₃ and CeO ₂ are often used as stabilizers, but when used as a setter, they should be thermally and mechanically stable, There is no particular need to limit the stabilizer. For example, Y ₂
If it is O ₃ , the molar ratio of Y ₂ O ₃ / ZrO ₂ is 1.5 / 9.
It is preferably 8.5 or more. If it is less than 1.5 / 98.5, the amount of monoclinic zirconia is large, and it becomes a setter having weak thermal shock resistance due to the transition, and cannot be reused.

Further, when the thickness of the setter is 3 mm or less, the mechanical strength becomes weaker when the above molar ratio exceeds 6.0 / 94.0. Therefore, the molar ratio is preferably 6.0 / 94.0 or less. .

In addition to the stabilizer and the unavoidable components,
In order to improve heat resistance and mechanical strength, Al ₂ O ₃ , Ti
An oxide such as O ₂ or SiO ₂ or a compound thereof may coexist. There is no need to limit the content unless it reacts with or adheres to the fired product during firing, but it is preferably used within the range of 0.05 to 30 mass% with respect to the total of zirconia and the stabilizer. This is because if the amount is more than 30% by mass, the original properties of zirconia deteriorate, such as the toughness decreases.

As the molding method of the setter, there are molding methods such as compression molding in which powder is molded by using a mold, and casting molding in which slurry is poured into a mold, but the method is not limited to the manufacturing method. Since the characteristics differ depending on the powder manufacturing method, it is necessary to select a molding method suitable for the characteristics of the powder as the raw material.

The zirconia-based setter used in the present invention is obtained, for example, by adding 5 wt% of yttria powder as a stabilizer to zirconia powder containing no stabilizer to zirconia, and pulverizing and mixing the mixture with wet. Obtain a slurry.
An acrylic binder is added to the obtained slurry and dried and granulated in the air using a spray drying device such as a rotating disk type to obtain a zirconia powder. The obtained powder is put into a mold and press-molded at a molding pressure of 50 kg / cm ² or less to obtain a low-pressure molded body. The upper punch of the mold was removed, and a value obtained by dividing the lower limit value of the opening of the sieve by the upper limit value from the 0.07 to 4 mm glass beads on an adhesive tape having the same cross-sectional area as the upper punch was 0.69. By adhering the particles whose particle size is adjusted as described above, placing the surface of the tape on which the glass beads are adhered toward the molded body, inserting the upper punch again, and press-molding with a molding pressure of 200 kg / cm ² or more. , A molded body having depressions formed on the surface is obtained, and the molded body is heated to 1300 to
By the method of firing at 1600 ° C., a setter having depressions on the surface can be obtained.

[0031]

As described above, the firing setter of the present invention has good heat resistance, and since the setter surface has a depression or a protrusion, the fired product and the setter are close to point contact, and the firing temperature is high. Even so, the fired product and the setter do not easily adhere to each other, and since there is no adhered substance such as a sintered sphere on the surface of the setter, foreign matter is not mixed in and the fired product is easily collected even if it is repeatedly used.

If this setter is used, even if a fired product containing many glass components is fired at a temperature close to the melting temperature of glass, the fired product and the setter are unlikely to adhere to each other, and the fired product can be easily collected. Also, since no bedding powder is used, there is no problem of industrial waste.

By using this firing setter, it is possible to meet strict requirements regarding manufacturing conditions, such as prevention of adhesion to the setter due to miniaturization of the fired product or prevention of adhesion due to higher firing temperature.

Further, by using this setter manufacturing method, the fine particles used for processing, or a tape or sheet to which the fine particles are adhered, or a processing method such as mechanical, heat or press is applied to the surface. The resin sheet with the depressions can be reused, and even in press molding with high production efficiency, it is not necessary to form unevenness on the mold surface, and it is inexpensive and easy to perform depressions or projections of any size. It is possible to manufacture a setter having

[0035]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 Commercially available zirconia beads TZ-BS250 (manufactured by Tosoh Corporation: size 212-300 μm) were used in the range of 250-30.
Commercially available masking tape (size: 199 mm × 199 mm × thickness 0.08 m) classified into a size of 0 μm
One sheet was prepared by adhering beads to the adhering surface of m).

Next, commercially available zirconia powder TZ-3YB
180 g (manufactured by Tosoh Corporation) is put in a molding die (molding size: 200 mm × 200 mm □), and 30 kg / c
Press molding was performed at a molding pressure of m ² . Furthermore, pull out the upper punch of the mold and set the bead side of the tape to the molded body,
After inserting the upper punch, press molding was performed again at a molding pressure of 300 kg / cm ² . The tape adhered to the surface of the obtained molded body is peeled off, the molded body is set on the firing setter, the warp prevention setter is placed on the upper surface of the molded body, and the temperature is maintained at 1500 ° C. for 2 hours in an electric furnace in an air atmosphere. After firing, the sintered body has a density of 6.01 g / cm ³ , and one side has a diameter of about 190 to 2
Zirconia-based setter with hemispherical depression surface in the range of 30 μm (150 mm × 150 mm × thickness 2 mm)
I got

On the recessed surface of this setter, 20 compacts each having a contact surface of barium titanate and having a length of 1 mm × 0.5 mm were placed.
Firing was performed under the conditions of ° C and holding for 2 hours. Also, the adhesive tape to which the beads were adhered could be reused.

Example 2 A commercially available zirconia bead TZ-BS355 (manufactured by Tosoh Corp .: size 300 to 425 μm) having a size of 19 was used.
Two sheets of commercially available cloth adhesive tape adhered to a 9 mm × 199 mm and a thickness of 0.5 mm were adhered to the adhesive surface to prepare two sheets.

Next, on the lower punch of the same molding die as in Example 1, the bead surface of the tape was laid up, 90 g of the same zirconia powder as in Example 1 was put into the die, and 50 kg / cm.
Press molding was performed at a molding pressure of ² . Further, the upper punch of the mold was pulled out, the bead surface of the remaining one piece of tape was set toward the molded body, and after the upper punch was inserted, it was press-molded again at a molding pressure of 300 kg / cm ² . The tape adhered to the surface of the obtained molded body was peeled off, the molded body was set on the sintering setter, the warp prevention setter was placed on the upper surface, and the sintered body was sintered under the same conditions as in Example 1 to obtain a sintered body density of 6.03 g. / Cm ³ , zirconia-based setter (150 mm ×) having a hemispherical depression surface with a diameter of approximately 230 to 330 μm on both surfaces.
150 mm × thickness 1 mm) was obtained.

On this setter, 20 compacts of barium titanate having a contact surface of length 2 mm × 1 mm were placed,
In an air atmosphere, it was fired in an electric furnace under conditions of 1330 ° C. and a holding time of 2 hours. Also, the adhesive tape to which the beads were adhered could be reused.

Example 3 Commercially available polyethylene sheet (PE, size: 199 mm
X 199 mm x thickness 1 mm) are prepared, and
Attached to the upper and lower punches of the molding die with double-sided tape, and further add commercially available zirconia beads TZ-BS125 (Tosoh Corp .: size 106-150 μm) 125-15
The material classified into a size in the range of 0 μm was put into a molding die, and a hemispherical recessed surface was formed on the sheet attached to the punch with a molding pressure of 200 kg / cm ² .

Next, the same zirconia powder 45 as in Example 1 was used.
g was put in the same mold as in Example 1 and press-molded at a pressure of 20 kg / cm ² . Further, the upper punch of the mold was pulled out, the recessed surface of the polyethylene sheet was set to face the molded body, and after the upper punch was inserted, it was press-molded again at a molding pressure of 400 kg / cm ² . Peel off the polyethylene sheet from the obtained molded body, set the molded body on the setter for firing, put the warp prevention setter on the upper surface, and fire it in an electric furnace in the atmosphere at 1500 ° C. for a holding time of 2 hours, Sintered body density 6.04 g / cm ³ , diameter on one side of about 95-115
Zirconia-based setter (150 mm x 150 mm x thickness 0.5 mm) with a hemispherical projection surface in the range of μm
I got

On the protruding surface of this setter, 20 compacts each having a contact surface of barium titanate and having a length of 1 mm × 0.5 mm were placed, and 1330 was formed by an electric furnace in an air atmosphere.
Firing was performed under the conditions of ° C and holding for 2 hours. Also, the polyethylene sheet could be reused.

Example 4 Commercially available glass beads BZ-1 (size 1 to 1.4 mm)
Is heated on a hot plate, a polycarbonate sheet (PC) of the same size as in Example 3 is attached to the upper punch of the molding die with double-sided tape and pressed onto the heated beads, and the sheet is sunk in a hemispherical shape. Was formed.

Next, the same zirconia powder 18 as in Example 1 was used.
0 g was put in the same mold as in Example 1 and press-molded at a pressure of 30 kg / cm ² . Furthermore, pull out the upper punch of the mold,
Set the recessed surface of the polycarbonate sheet toward the molded body, insert the upper punch, and at a molding pressure of 200 kg / cm ² ,
It was pressed again. Peel off the polyethylene sheet from the obtained molded body, set the molded body on the setter for firing, put the warp prevention setter on the upper surface, and fire it in an electric furnace in the atmosphere at 1500 ° C. for a holding time of 2 hours, Sintered body density 6.00 g / cm ³ , diameter on one side is about 0.7
A zirconia-based setter (150 mm x 150 mm x thickness 2 with a hemispherical projection surface in the range of 8 to 1.1 mm)
mm).

Twenty compacts of barium titanate having a contact surface with a length of 5 mm × 1.5 mm were placed on the protruding surface of this setter.
Firing was performed under the conditions of ° C and holding for 2 hours. Also, the polycarbonate sheet could be reused. Comparative Example 1 Commercially available glass beads BZ-4 (size 4 to 4.7 mm)
In the same manner as in Example 4, except that the sintered body has a density of 6.00 g / cm ³ and a diameter of about 3.1 to 3.7 on one side.
A zirconia-based setter (150 mm × 150 mm × thickness 2 mm) having a hemispherical projection surface in the range of mm was obtained.

Twenty compacts of barium titanate having a contact surface of 5 mm × 1.5 mm were placed on the protruding surface of this setter, and 1330 was formed by an electric furnace in the atmosphere.
Firing was performed under the conditions of ° C and holding for 2 hours.

The polyethylene sheet could be reused,
Since the diameter of the protrusion was larger than 1/2 of the maximum length of the surface where the calcined product and the setter contacted each other, the effect of point contact was poor, and part of barium titanate was bonded and deformed.

Comparative Example 2 A double-sided tape was attached to the upper punched powder part of the same molding die as in Example 1, and zirconia beads of the same size as in Example 1 were bonded.

Next, the same zirconia powder 18 as in Example 1 was used.
0 g was put in a molding die and press-molded at a pressure of 300 kg / cm ² .

When the molded body was taken out of the mold, the molded body adhered to the upper punch and the molded body was damaged when it was removed.

Comparative Example 3 A double-sided tape was attached to a stainless steel thin plate (thickness 0.3 mm) of the same size as the masking tape of Example 1, and Example 2 was used.
The same zirconia beads classified into a size in the range of 425 to 500 μm as described above were adhered.

Next, press molding was carried out in the same manner as in Example 1 except that a Stentes thin plate was used instead of the masking tape.

The molded body was taken out, but the molded body adhered to the stainless thin plate, and the molded body was damaged when it was removed.

In Table 1 below, Examples 1 to 4 and Comparative Example 1
The diameter (μm) of one depression or protrusion of the setter obtained in 3 to 3, 1/2 (μm) of the maximum contact length, and the presence or absence of adhesion with the fired product are shown.

[0057]

[Table 1]

As is clear from this table, the setters of the examples of the present invention are excellent setters without adhesion to the fired product.

[Brief description of drawings]

FIG. 1 is a view showing a cross-sectional view of a setter having a hemispherical depression.

FIG. 2 is a view showing a cross-sectional view of a setter having saw-like irregularities.

FIG. 3 is a diagram showing a cross-sectional view of a setter having comb-shaped irregularities.

FIG. 4 is a view showing a cross-sectional view of a setter having hemispherical protrusions.

[Explanation of symbols]

 a: The diameter of the depression or protrusion (mm).

Claims (3)

[Claims] 1. A setter for firing, characterized in that a depression or projection having a diameter in the range of more than 0.05 mm and less than 3 mm is formed on one side or both sides of the setter. 2. The material of the setter according to claim 1, wherein the ceramics are alumina, silica, magnesia, mullite, zirconia, cordierite, silicon nitride, silicon carbide, and the like.
Alternatively, the firing setter is made of a composite material containing these as main components. 3. Spherical or irregularly shaped fine particles, a tape or sheet to which the fine particles are adhered, or mechanical processing, heat processing,
Using a resin sheet with a depression formed on the surface by pressing or molding, by pressing, tape molding, or casting molding method, the surface of the molded article is depressed or projections are formed, and then baked. A method of manufacturing a setter for firing, comprising: