JP2014148436A - Method for manufacturing burned tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a burned tool which can appropriately come in contact with a mating material when being used.SOLUTION: The method for manufacturing the burned tool comprises the steps of: burning a mixed powder having a fine ceramic powder and a pore-forming agent; and then polishing a part that becomes a surface.

Description

  The present invention relates to a method for manufacturing a firing jig having features on the surface.

  Devices such as electronic components and semiconductor devices are manufactured through a firing process (heat treatment process). Generally, such a device is prepared by preparing and shaping the raw material, placing it on the surface of a firing jig such as a setter (on the mounting surface), and firing (heat treatment) at a high temperature in a heating furnace, It is manufactured by making a ceramic fired body and then assembling it after processing such as forming an electrode on it.

  Examples of devices such as electronic components include ceramic capacitors, ceramic piezoelectric materials, microwave dielectrics, high frequency filters, semiconductor capacitors, thermistors, ceramic varistors, ceramic sensors, etc. Examples thereof include ceramic materials such as barium, lead zirconate titanate, strontium titanate, zinc oxide, zirconium oxide, rare earth oxides, and composites thereof.

  These devices are manufactured by firing a raw material containing a resin-based binder in a ceramic material. This binder is not contained in the fired body (device to be manufactured) by evaporating at a high temperature during firing.

  If the binder transpiration is insufficient, the binder will remain in the device. The binder remaining in the device partially changes the characteristic of the resistance value. That is, the device cannot exhibit desired characteristics. That is, a device manufactured by baking becomes a defective product. For this reason, as described in Patent Document 1, a setter on which a device (object to be processed) is mounted at the time of firing is required not to hinder binder evaporation.

  In order not to disturb the transpiration of the binder during firing, the surface of the firing jig is blasted to form irregularities on the surface (the surface on which the object is to be treated) and fine gaps are formed. The binder is diffused from the workpiece.

  Further, the firing jig is required to suppress the reaction with the object to be processed. When a reaction occurs between the firing jig and the object to be processed, the reaction product causes a deterioration in the characteristics of the object to be processed after baking. Furthermore, when a reaction occurs between the firing jig and the workpiece, there is a problem that the particles used as the raw material of the firing jig react (sinter) with the workpiece and adhere to the workpiece. It was.

  The firing jig is required to have sufficient strength. Conventionally, a densely formed firing jig has been used to meet this requirement, but the dense firing jig has a problem that it is vulnerable to thermal shock. That is, when the firing jig is repeatedly used, there is a problem that the firing jig is damaged due to thermal shock.

  For such a problem, it is conceivable to form a firing jig using coarse particles. When a firing jig is formed using coarse particles, the firing jig becomes a porous body, which is considered to improve the thermal shock resistance.

  However, when the firing jig is formed from coarse particles, there is a problem that particles resulting from the coarse particles are peeled off to contaminate the workpiece. In some cases, there is a problem that a problem that the separated coarse particles are likely to adhere to the object to be processed (reaction occurs and the reaction product adheres) is likely to occur.

JP 2006-225186 A

  This invention is made | formed in view of the said actual condition, and makes it a subject to provide the manufacturing method of the baking jig which can obtain a suitable contact with respect to the other party material at the time of use.

  In order to solve the above-mentioned problems, the present inventors have studied the method for producing a firing jig, and as a result, have come to make the present invention.

  Moreover, the manufacturing method of the firing jig of the present invention is a mixed powder having a ceramic powder having an average particle size of 0.3 to 2.0 μm and a pore-forming agent having an average particle size of 1 to 20 μm that disappears by heat treatment. And a step of molding the mixed powder, a step of eliminating the pore-forming agent and firing the molded body, and a step of polishing the surface of the firing jig.

  The method for producing a firing jig of the present invention can produce a firing jig in which a concave recess is formed on the surface in contact with the mating member. When the mating member is placed on the surface of the manufactured firing jig, appropriate contact with the mating member can be obtained through the concave depression.

It is the figure which showed the setter of the Example. It is the figure which showed the surface state of the setter of the sample 1. It is the figure which showed the surface state of the setter of the sample 2. FIG. It is the figure which showed the surface state of the setter of the sample 3. It is the figure which showed the surface state of the setter of the sample 4. FIG. 6 is a view showing a surface state of a setter of sample 5. It is the figure which showed the surface state of the setter of the sample 6. It is the figure which showed the surface state of the setter of the sample 7 (flat plate). It is the figure which showed the surface state of the setter of the sample 8 (blast). It is a flowchart which shows a process when using the setter of an Example repeatedly. It is the figure which showed the setter of the deformation | transformation form. It is the figure which showed the usage pattern of the setter of a deformation | transformation form.

(Method for manufacturing firing jig)
The production method of the present invention comprises a step of preparing a mixed powder having a ceramic powder having an average particle size of 0.3 to 2.0 μm and a pore-forming agent having an average particle size of 1 to 20 μm, and forming the mixed powder A step of firing, a step of firing the molded body, and a step of polishing the surface of the firing jig.
The method for producing a firing jig of the present invention can produce a firing jig which is entirely made of a porous body.

  The step of preparing the mixed powder is a step of preparing a mixed powder as a raw material for the firing jig, and a firing jig made of a porous body can be manufactured by performing each subsequent process. A firing jig made of a porous material exhibits high thermal shock resistance due to its pore structure.

  In the manufacturing method of the present invention, the prepared mixed powder has a fine ceramic powder and a pore-forming agent. By being a mixed powder of these fine powders, a relatively dense firing jig having fine pores can be produced.

  In the production method of the present invention, ceramic powder having an average particle size of 0.3 to 2.0 μm is fired. In this invention, an average particle diameter shows a median diameter (D50). A porous mounting surface can be formed by firing a fine ceramic powder having an average particle size of 0.3 to 2.0 μm. In addition, since the ceramic powder is formed of fine particles, a relatively dense surface (having few pores) can be formed. A relatively dense surface is excellent in strength.

  Further, since the ceramic powder particles are strongly sintered by forming the surface from a fine ceramic powder, the fine ceramic powder when used as a firing jig for heat treatment of the mating member (object to be processed) Can be prevented from reacting and adhering to the workpiece.

  When the average particle size of the ceramic powder is less than 0.3 μm, the particle size becomes too small, the fluidity is deteriorated, and the variation in density at the time of molding increases. When the average particle diameter exceeds 2.0 μm, the particle diameter becomes too large, and the ceramic particles easily adhere to the object to be processed. A more preferable average particle diameter is 0.4 to 1.5 μm.

  The ceramic powder preferably shows one sharp peak when the particle size distribution is measured. That is, the ceramic powder is preferably a powder having a relatively uniform particle size. In the powder having a broad peak in particle size distribution, the ratio of coarse particles increases due to variations in the particle size of ceramic particles, and the strength of the surface of the firing jig decreases.

  In the production method of the present invention, the ceramic powder is fired together with a pore-forming agent having an average particle diameter of 1 to 20 μm. The pore-forming agent is fine particles (powder made) that disappear as a result of firing (heat treatment) and function as a pore-forming agent having a sintered body as a porous body. That is, by firing together with the pore-forming agent, the pore-forming agent disappears at the time of firing, and the fired body and firing jig after firing become a porous body. In the porous body, the exposed pores become the above-described concave depression.

  When the average particle diameter of the pore former is 1 to 20 μm, a porous body capable of obtaining a predetermined surface roughness is obtained. When the average particle diameter is less than 1 μm, the particle diameter becomes too fine and the effect of pore formation cannot be obtained sufficiently. On the other hand, if the average particle diameter exceeds 20 μm, the particle diameter becomes too large, the porosity increases, and the strength of the sintered body decreases. Furthermore, it becomes difficult to form a desired surface.

  In the production method of the present invention, the ratio of the ceramic powder and the pore-forming agent in the mixed powder is not particularly limited, and it is preferable to mix so as to obtain desired characteristics. For example, it is preferable to contain in the ratio of ceramic powder: 70-95 mass parts, pore making material: 5-30 mass parts.

  In the production method of the present invention, conventionally known additives can be added to the mixed powder in addition to the ceramic powder and pore former. Further, regarding the mixing ratio of these, the material and the addition amount (ratio) are appropriately determined so as to obtain desired characteristics.

  The mixed powder to be prepared is preferably such that ceramic powder, pore former, other additives and the like are uniformly mixed. By uniformly mixing the mixed powder, pores are uniformly formed in the firing jig made of the produced porous ceramic.

  In the production method of the present invention, the specific adjustment method is not limited as long as the step of preparing the mixed powder is a step capable of preparing the mixed powder. For example, a method of thoroughly mixing ceramic powder and pore former (and additive) in a dry state, and ceramic powder and pore former (and additive) are dispersed in a solvent (for example, water) and kneaded (mixed). The method etc. can be mention | raise | lifted.

  As described above, in the present invention, the mixed powder indicates that each powder is in a mixed state, and not only indicates the powder state but also a clay (or mixed powder dispersed in a solvent (or , In the form of a slurry).

  In the step of forming the mixed powder, the mixed powder is formed into the shape of the firing jig (each shape used). As long as this shaping | molding process is a process which can shape | mold a mixed powder, the specific shaping | molding method is not limited. For example, a method of extruding and molding a clay-like mixed powder, a method of molding a slurry-like mixed powder using a predetermined mold, and a compacting method of compressing and molding a powder-like mixed powder can be mentioned.

When the step of molding the mixed powder is compacting, the compacting pressure may be any pressure that allows the compact to have a desired density. A preferable pressure is 600-1400 kgf / cm < ² >, and a more preferable pressure is 800-1200 kgf / cm < ² >.

  In the step of forming the mixed powder, the shape to be formed is not particularly limited. That is, it is preferable to form into the shape of the firing jig manufactured by the manufacturing method of the present invention.

  The molded body is preferably subjected to a degreasing step in which the molded body is heated at a temperature lower than that of a firing step described later. By performing the degreasing step, it is possible to suppress an improvement in manufacturing efficiency and damage to the heating furnace in which baking is performed. The specific method of the degreasing step is not particularly limited, and is preferably a step of heating in an oxidizing atmosphere. The oxidizing atmosphere can be obtained by oxygen alone or a gas mixed with an inert gas. Examples of the inert gas include nitrogen gas and argon gas, and argon gas is more preferable. Moreover, it is preferable that heating temperature is 350-600 degreeC. Further, the amount of degreasing is not particularly specified as well, but it is better to degrease to 80% or more.

  The formed body is preferably subjected to a drying step before the firing step and the degreasing step described below. By performing a drying process, it can suppress that the water | moisture content in a molded object reduces the dimensional accuracy of a molded object at the time of baking. A specific method of the drying step is not limited as long as the method can dry the molded body.

  A specific firing method is not limited as long as the step of firing the formed body is a step capable of firing the formed body (sintering the ceramic powder and eliminating the pore-forming agent). For example, a step of heating at a predetermined temperature can be given.

  In the step of firing the molded body, the firing conditions are not particularly limited, and the temperature and time can be used to fire the molded body (sinter the ceramic powder and eliminate the pore-forming agent). be able to. The same applies to conditions such as the heating rate. When the firing conditions are within these ranges, the firing jig has desired characteristics (excellent characteristics). If any of the firing conditions is reduced (smaller), the amount of heat at the time of firing is insufficient, the sinterability of the ceramic powder is reduced, and the pore-forming agent remains. Further, if any of the sintering conditions is increased (larger), the sintering of the ceramic powder proceeds excessively, the densification proceeds, and it becomes difficult to obtain a desired porosity.

  The atmosphere in which the firing is performed is not limited and may be either an air atmosphere or an inert gas atmosphere. Preferably, it is an air atmosphere containing oxygen that promotes the disappearance of the pore-forming agent.

  The step of polishing the firing jig is a step of polishing the surface of the firing jig. By polishing the surface of the firing jig, not only can the polished surface be smoothed, but also impurities present on the surface of the firing jig can be removed. In addition, by this polishing, the fine pores inside the porous body are exposed, and fine concave depressions resulting from the fine pores can be formed on the surface. That is, by polishing the firing jig, it is possible to form a surface having a concave recess and having a predetermined surface roughness.

Polishing of the firing jig is preferably performed so that the polished surface has a planar shape with an open concave recess. The polished surface has a flat shape with an open recess, so that the mounting surface becomes flat without distortion, and even if the surface of the firing jig is in contact with the mating member and heat-treated, the mating member is not distorted. No longer occurs.
The firing jig is preferably polished so that the load length ratio (Mr1) specified in JIS B 0671-2 is 10% or less.

The load length ratio (Mr1) indicates the ratio of the convex portions of the concave and convex portions on the surface of the firing jig having fine concave and convex portions (concave opening). That is, when the firing jig is in contact with the mating member on the surface, the ratio of the portion in point contact with the mating member is shown. And the surface of the baking jig | tool obtained by grinding | polishing with the manufacturing method of this invention can contact an other party member in more areas because Mr1 will be 10% or less. Here, when Mr1 exceeds 10%, the contact area with the mating member increases, and malfunctions due to an increase in the contact area with the mating member (for example, the mating member is distorted or reacts with the mating member). Occurring and contaminating the mating member).
A preferable load length ratio (Mr1) is 8% or less, more preferably 7% or less.

  The firing jig is preferably polished so that the load length ratio (Mr2) specified in JIS B 0671-2 is 70% or more.

The load length ratio (Mr2) indicates the ratio of the firing jig to the surface of the firing jig having fine irregularities (concave opening). That is, the ratio of the part which is in contact with the other member when the firing jig is in contact with the other member on the surface is shown. And when Mr2 is 70% or more, the mating member can be contacted with an appropriate area. Here, if Mr2 is less than 70%, the mating member is likely to be distorted while the surface is in contact with the mating member.
A preferable load length ratio (Mr2) is 75% or more.

  The firing jig is preferably polished so that the level difference (Rk) specified in JIS B 0671-2 is 1 to 5 μm.

If the level difference (Rk) exceeds 5 μm, the contact area with the mating member will be too small, and the contact area between the mating member and the firing jig will be too small (for example, supporting the mating member sufficiently) It is not possible to cause deformation of the mating member or to generate a reaction product at the contact portion). When the level difference (Rk) value is less than 1 μm, there are too few voids (portions that do not come into contact with the mating member) on the surface of the firing jig, the transpiration of the binder becomes insufficient, and the binder removal property can be maintained. Disappear.
A preferable level difference (Rk) is 1 to 4 μm, more preferably 1 to 3 μm.

The polishing of the firing jig is preferably performed so that the surface roughness (Ra) is 10.00 or less.
When the surface roughness (Ra) is 10.00 or less, the surface is provided with a fine depression (a depression having a narrow opening width). Since the dents on the surface are fine, the mating member is not distorted when the firing jig and the mating member come into contact with each other. When the roughness of the surface becomes rough, deformation (distortion) is likely to occur so that the counterpart member itself enters between the recesses opened in the surface, and the dimensional accuracy of the counterpart member is likely to be reduced.

The preferred surface roughness (Ra) is 8.00 or less, more preferably 7.00 or less. In the present invention, the surface roughness (Ra) can be determined by a method defined in JIS B 0601.
The firing jig is preferably polished so that the surface roughness (Rz) is 75.00 or less.

  When the surface roughness (Rz) is 75.00 or less, it is possible to prevent the firing jig from adhering to or contaminating the mating member in contact with the firing jig. When the surface roughness (Rz) exceeds 75.00, the concave depression on the surface becomes too deep, and the side wall surface defining the depression cannot maintain strength, and peeling is likely to occur. When peeling occurs on the side wall surface, the peeled off piece comes to adhere to the mating member.

The preferred surface roughness (Rz) is 60.00 or less, more preferably 50.00 or less. In the present invention, the surface roughness (Ra) can be determined by a method defined in JIS B 0601.
The firing jig is preferably formed to have a porosity of 10 to 50%. The porosity of the firing jig is more preferably 10 to 45%.

  When the porosity of the firing jig falls within this range, the thermal shock resistance and strength of the firing jig are excellent. In addition, the surface roughness can be easily set within a predetermined range. If the porosity is less than 10%, the firing jig becomes dense and the thermal shock resistance is lowered. On the other hand, if the porosity exceeds 50%, the amount of pores increases, the strength decreases, and peeling easily occurs from the firing jig. When peeling occurs, the peeled pieces that peel off contaminate the mating member when used in contact with the mating member. Furthermore, when the porosity becomes too high, reaction / adhesion between particles (particles for forming a porous body) constituting the firing jig and the counterpart member tends to occur.

  In the production method of the present invention, the specific method of polishing the firing jig is not particularly limited, and is performed by the same method as the surface treatment method used when smoothing the surface of dense ceramics. Can do. For example, a method of cutting and smoothing the surface irregularities and a method of polishing the surface using a grindstone can be given. Further, the polishing of the firing jig may be performed at one time or in multiple stages. That is, precision polishing (finish polishing) may be performed after rough polishing.

  In the production method of the present invention, the material of the ceramic powder is not limited. That is, a conventionally known ceramic powder material can be used. For example, examples of the material for the firing jig include zirconia, alumina, mullite, spinel, silicon nitride, silicon carbide, or a composite material thereof. Of these, zirconia is more preferable.

In the present invention, the zirconia powder is not only a powder made of zirconium oxide (ZrO ₂ ), but is a partially stabilized zirconia in which elements such as yttrium, cerium, calcium, magnesium, and rare earth elements are added to zirconium oxide. Containing powder. The ratio of the additive element in the partially stabilized zirconia is not particularly limited, and can be a conventionally known ratio (for example, 3.0 to 8.0 mol%). The zirconium oxide may contain hafnium oxide (HfO ₂ ) that is difficult to separate.

  In the present invention, the material of the pore former is not limited as long as it is a fine particle (powder made of) that disappears when fired and functions as a pore former having a firing jig as a porous body. Absent. An example of the pore-forming agent is microbeads.

  The micro beads are preferably made of at least one of acrylic resin and phenol resin. When the microbead is made of a resin selected from these resins, the pores of the fired body can have a desired pore diameter (pore characteristics). Microbeads made of at least one of an acrylic resin and a phenolic resin generate less heat than the microbeads made of only carbon when they disappear during firing.

Further, the microbead may be solid or a hollow body having a hollow inside.
The firing jig manufactured by the manufacturing method of the present invention is preferably a setter that performs heat treatment in a state where an object to be heat treated is placed on the surface.

  The production method of the present invention can produce a firing jig formed of a porous body whose surface is polished. This firing jig is made of a porous body whose surface that comes into contact with the mating member is polished, so that it comes into contact with the mating member as the object to be processed, and contamination of the mating member due to peeling is prevented. In particular, it is preferable to use as a setter in order to exhibit an effect that not only can be suppressed but also can suppress the occurrence of distortion in the counterpart member.

  In the present invention, the shape of the firing jig is not limited, and can be, for example, the same shape as that of a conventionally known firing jig. The firing jig of the present invention has, for example, a plate shape whose surface is a mounting surface, a shape that supports a plate with feet (protrusions), a tank shape, and the like so that a plurality of layers can be stacked with a space therebetween be able to.

  As described above, the firing jig (setter) manufactured according to the present invention may cause peeling or reaction and adhesion / contamination when the mating member (object to be processed) is heat treated. And the occurrence of distortion of the object to be processed is suppressed. For this reason, it is preferably used for heat treatment (firing) of devices such as electronic components and semiconductor devices.

Hereinafter, the present invention will be specifically described with reference to examples.
As an embodiment of the firing jig of the present invention, a flat setter was manufactured.
(Example embodiment)
(Samples 1-6)
First, zirconia powder and microbeads were weighed and prepared in the proportions shown in Table 1.

The zirconia powder used in this embodiment has an average particle size (D50) of 0.5 μm, and 8 mol% of yttria (Y ₂ O ₃ ) added to zirconium oxide (ZrO ₂ ). Was used. As the microbeads, a powder made of at least one of solid acrylic resin particles and phenol resin particles having an average particle diameter (D50) of 5 μm was used.

Each of the weighed and prepared powders was mixed well until a uniform mixed state was obtained, thereby preparing a mixed powder.
The mixed powder was molded by press molding into a square plate using a mold. This molding was performed by applying a pressure of 1000 kgf / cm ² .
Next, the molded body was naturally dried, and then degreased by being kept at 400 ° C. for 24 hours.

After degreasing, it was calcined by holding at 1500 ° C. for 2 hours in air atmosphere (sintered partially stabilized zirconia and disappeared microbeads). After firing, a plate-like fired body (sintered body) was obtained by cooling by cooling.
The surface (both surfaces) of the obtained plate-like fired body was polished. Surface polishing was performed by a surface polishing machine.
Thus, setters for Samples 1 to 6 were manufactured.

  The setters 1 of the manufactured samples 1 to 6 had a plate shape of 150 × 150 × 3 mm as shown in FIG. Further, in the setter 1 of each sample, both surfaces (10a, 10b) of the plate are mounting surfaces on which the object to be processed is placed.

(Samples 7-8)
A plate-like fired body (sintered body) was produced in the same manner as in samples 1 to 6. The blending of raw materials is shown in Table 1. As shown in Table 1, the setters of Samples 7 to 8 are dense because they do not use microbeads that are pore forming agents.
The produced plate-like fired body was used as a setter for Sample 7 (flat plate).
Moreover, the setter of the sample 8 (blast) was manufactured by blasting the surface of the manufactured plate-like fired body.

  Measurement results of load length ratio (Mr1, Mr2), level difference (Rk), surface roughness (Ra), (Rz) and porosity of the setter mounting surface (10a) of each manufactured sample Are shown in Table 2.

(Load length ratio, level difference)
The measurement of load length ratio (Mr1, Mr2) and level difference (Rk) was performed using the method prescribed | regulated to JISB0601-2.

(Surface roughness)
The surface roughness (Ra) and (Rz) were measured using the method specified in JIS B 0601.

(Porosity)
For measuring the porosity, the mounting surface of the setter was measured according to JIS R 2205.

As shown in Table 2, Sample 1 is a relatively dense setter having a porosity of 26%, and has a surface roughness (Ra) of 3 and (Rz) of 15. Samples 2 to 5 are setters having a porosity of 18 to 48%, a surface roughness (Ra) of 2 to 4.5, and a surface roughness (Rz) of 10 to 23. Sample 6 is a porous setter having a porosity of 56%, and has a surface roughness (Ra) of 5 and (Rz) of 25. Samples 7 to 8 are setters having a smooth or uneven surface.
Furthermore, the state of the surface (mounting surface) of each sample was evaluated.

  First, the setter surface (mounting surface) of each sample was confirmed. The setters of Samples 1 to 6 and the setter of Sample 7 whose surfaces were polished at the time of manufacture were smooth surface plates. The setter of Sample 8 where the surface was not polished had irregularities on the surface.

  Next, the uneven shape (surface roughness) of the surfaces (mounting surfaces) of Samples 1 to 6 and 7 to 8 was measured and shown in FIGS. 2 shows sample 1, FIG. 3 shows sample 2, FIG. 4 shows sample 3, FIG. 5 shows sample 4, FIG. 6 shows sample 5, FIG. 7 shows sample 6, FIG. Fig. 9 shows the surface irregularity state of sample 7 and Fig. 9 shows sample 8 respectively. 2 to 9 were measured using a surface roughness meter (trade name: Surfcom 1400, manufactured by Tokyo Seimitsu Co., Ltd.).

  As shown in FIGS. 2 to 7, the setters of Samples 1 to 6 have a concave recess having a substantially V-shaped cross section on the surface of the mounting surface, that is, a convex shape on the surface. It can be confirmed that there is no portion. Furthermore, it can be confirmed that the setters of Samples 1 to 6 have a substantially flat surface on which no concave depression is formed. It can be seen that this surface was formed by polishing the surface after firing the porous body.

  As can be seen from FIGS. 2 to 7, it can be confirmed that the surface roughness (Ra and Rz) increases as the porosity increases. That is, it can be seen that the surface of the mounting surface was polished to expose the pores, thereby forming a concave recess on the surface.

  Further, as shown in FIG. 8, the setter of the sample 7 (flat plate) is a surface formed by sintering without using microbeads and the surface of the mounting surface is substantially smooth and has unevenness. It can be confirmed that there is not. As shown in FIG. 9, the setter of the sample 8 (blast) can confirm that the surface of the mounting surface has an uneven shape. It can be seen that these surfaces were formed by the surface state of the porous body in a fired state (the surface was not polished) or by blasting.

  The setters of Samples 1 to 6 have a surface on which a concave recess is formed, and when used as a firing jig, it is possible to obtain an appropriate contact with the workpiece placed on the surface. Recognize. On the other hand, the setter of the sample 7 (flat plate) has a substantially smooth surface, and when used as a firing jig, the evaporation of the binder from the workpiece placed on the surface becomes insufficient. The setter of the sample 8 (blast) is a surface having a concavo-convex shape, and in particular, the tip of the convex portion and the object to be processed are likely to be sintered, and the shape change (size) of the object to be processed is fine. (Decrease in accuracy) is likely to occur.

(Evaluation)
As an evaluation of the setter of each sample, the moldability and the thermal shock temperature were examined and are shown in Table 2 respectively.

(Formability)
□ Molded to 200 × 200 × 4 mm and visually judged for cracks and chips. In Table 2, a sample in which cracks and burrs could not be confirmed was indicated by ◯, a fine crack and samples in which burrs could be confirmed were marked by △, and a sample that could not be used as a setter was marked by ×.

  Even in the setters of Samples 1 to 8, cracks and chips that were evaluated as x and could not be used could not be confirmed. In the setter of sample 6, a chip was confirmed, but it was a fine chip that did not affect the use as a setter, and there was no problem in actual use.

(Heat shock temperature)
For measurement of the thermal shock temperature, first, the setter of each sample is processed to 150 × 150 × 3 mm and heated (heated) to a predetermined heating temperature of 180 to 300 ° C. in a state where it is placed in a heating furnace. When the furnace temperature is stabilized at the heating temperature, it is determined that the setter of each sample is sufficiently heated, and the setter of each sample is taken out from the heating furnace and allowed to cool (rapidly cool) at room temperature (25 ° C.). When the temperature of each sample reaches the same temperature as the room temperature, the sample is again put into the heating furnace and heated (heated) to the heating temperature.
The temperature rise (heating) to this heating temperature and the cooling to room temperature (rapid cooling) were repeated 5 times, and the temperature at which the setter did not crack was defined as the thermal shock temperature.

  As shown in Table 2, it can be confirmed that the thermal shock temperature increases as the porosity increases. The setters of Samples 1 to 6 all have a thermal shock temperature of 250 ° C. or higher. Moreover, the setters of Samples 7 to 8 are dense by not using a pore-forming agent, and the thermal shock temperature is as low as 180 ° C.

  As described above, all of the setters of Samples 1 to 6 can obtain an appropriate contact with the object to be processed and have a thermal shock temperature of 250 ° C. or higher. Moreover, not all of the setters of the samples 7 to 8 can obtain an appropriate contact with the object to be processed, and the thermal shock temperature is significantly lower than the setters of the samples 1 to 6.

(Example of usage of setter)
As described above, the setter (firing jig) of the present invention manufactured in the examples has excellent thermal shock resistance. Therefore, it can be repeatedly used as a setter for heat treatment of an object to be processed. The repeated use can be performed as follows, for example. A flowchart of repeated use is shown in FIG.
A workpiece is placed and heat treated, and then the state of the setting surface of the setter is observed.
When the observation result is in a state where it can be used as a setter, it is again used for heat treatment of the object to be processed.

When the observation result is in a state unsuitable for use as a setter (for example, a state in which the surface roughness (Ra, Rz) is too large or warping or distortion occurs), the mounting surface is polished. Apply. Here, the polishing process can be the same as the process performed when polishing the fired body during the production of the setter.
After polishing, it is used for heat treatment of the object to be processed.

  As described above, the setter of the present invention can form a placement surface on which a new object is placed by performing a polishing process. That is, it can be used repeatedly as a setter.

(Deformation)
The setter (firing jig) of the present invention can have various shapes other than the plate-shaped setter.
For example, as shown in FIG. 11, a substantially table-shaped setter 1 in which legs (12) are erected on the peripheral edge of a plate-like mounting portion (11) whose upper surface (11a) is a mounting surface. I can give you. As shown in FIG. 12, the setter 1 can be used in a state where a plurality of the setters 1 are stacked. In this case, the plurality of objects to be processed 2 can be heat-treated at a time by placing the objects to be processed (2, 2,...) On the respective setters (1, 1,...).

  In the setter of this embodiment, the plate-like placement portion (11) and the leg portion (12) may be formed of the same material or different materials. Moreover, even if the plate-shaped mounting part (11) and the leg part (12) are integrally formed, they may be formed separately.

1: Setter 11: Placement part 12: Leg part 2: Object to be processed

Claims (11)

A step of preparing a mixed powder having a ceramic powder having an average particle size of 0.3 to 2.0 μm and a pore former having an average particle size of 1 to 20 μm that disappears by heat treatment;
Forming the mixed powder;
Disposing the pore-forming agent and firing the molded body;
Polishing the surface of the firing jig;
The manufacturing method of the baking jig characterized by having.   The method for manufacturing a firing jig according to claim 1, wherein the polishing of the firing jig is performed so that a level difference (Rk) defined in JIS B 0671-2 is 1 to 5 µm.   The method for manufacturing a firing jig according to claim 1, wherein the firing jig is polished so that a load length ratio (Mr1) defined in JIS B 0671-2 is 10% or less. .   The method for manufacturing a firing jig according to any one of claims 1 to 3, wherein the polishing of the firing jig is performed such that a load length ratio (Mr2) defined in JIS B 0671-2 is 70% or more. .   The method for manufacturing a firing jig according to any one of claims 1 to 4, wherein the polishing of the firing jig is performed such that the surface roughness (Ra) is 10.00 or less.   The method for manufacturing a firing jig according to any one of claims 1 to 5, wherein the polishing of the firing jig is performed so that the surface roughness (Rz) is 75.00 or less.   The method for manufacturing a firing jig according to claim 1, wherein the firing jig is formed to have a porosity of 10 to 50%.   The method for manufacturing a firing jig according to claim 1, wherein the ceramic powder is zirconia powder.   The method for manufacturing a firing jig according to claim 1, wherein the pore former is a microbead.   The method for manufacturing a firing jig according to claim 9, wherein the micro beads are made of at least one of an acrylic resin and a phenol resin.   The method for manufacturing a firing jig according to claim 1, wherein the firing jig is a setter that performs a heat treatment in a state where an object to be heat-treated is placed on the surface.

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