JP6810075B2 - Firing jig - Google Patents

Description

The present invention relates to a firing jig.

Devices such as electronic components and semiconductor devices are manufactured through a firing process (heat treatment process). In general, such a device is placed on a plate-shaped setter (firing jig) having a smooth surface (mounting surface) after the raw materials are mixed and molded, and fired (heat-treated) at a high temperature in a heating furnace. This makes a ceramic fired body, and then it is manufactured by processing such as forming an electrode on it and finally assembling it.

Examples of devices such as electronic components include ceramic capacitors, ceramic piezoelectric materials, microwave dielectrics, high-frequency filters, semiconductor capacitors, thermistas, ceramic varistor, ceramic sensors, etc., and examples of the raw materials thereof include titanium acid. Examples thereof include ceramic materials such as barium, lead zirconate titanate, strontium titanate, zinc oxide, zirconite oxide, rare earth oxides, and composites thereof.

These devices are manufactured by firing a raw material containing a binder such as a resin in a ceramic material. This binder is not contained in the fired body (manufactured device) because it is gasified and evaporated due to the high temperature during firing.

Insufficient evaporation of the binder will leave the binder in the manufactured device. The binder remaining in the device partially changes the characteristics of the resistance value. That is, the device cannot exhibit the desired characteristics. That is, the device manufactured by firing is a defective product. For this reason, the setter on which the device (object to be fired) is mounted during firing is required not to interfere with the evaporation of the binder.

To solve this problem, the surface of the setter is subjected to surface blasting so as not to interfere with the evaporation of the binder during firing to form fine irregularities on the surface (the surface on which the object to be fired is placed) to form fine gaps. There is a way to do it (specifically). In this method, the binder from the object to be fired passes through the gap formed and diffuses.
However, in the surface blasting method, the surface has a fine uneven shape, so that the effect is not sufficiently exhibited.

As another method, as described in Patent Document 1, there is a method of forming irregularities on the surface. Specifically, a setter in which the size of the uneven portion is 1 mm or less, the distance between the bottom surfaces between the uneven portions is 0.5 mm or less, and the height is 0.2 mm or less is described. This setter also prevents reactivity with the object to be fired, that is, fusion of the object to be fired.
However, the setter described in Patent Document 1 has not fully exhibited its effect.

As yet another method, as described in Patent Document 2, there is a method of forming the surface as a predetermined flat state having fine irregularities on the surface. Specifically, a firing jig in which the level difference (Rk) on the surface is adjusted is described. This firing jig also prevents reactivity with the object to be fired, that is, fusion of the object to be fired.
However, even in the firing jig described in Patent Document 2, the effect was not sufficiently exhibited.

Japanese Unexamined Patent Publication No. 2006-225186 Japanese Unexamined Patent Publication No. 2014-148435

However, the unevenness of the surface (placement surface on which the object to be fired is placed) formed by the blast treatment is a fine unevenness, and when the vaporized binder fills the unevenness, the unevenness becomes the object to be fired. If a closed space is formed between the binders, the binder may not be able to diffuse from the object to be fired.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a firing jig capable of diffusing a binder during heat treatment.

As a result of repeated studies on the firing jig in order to solve the above problems, the present inventors have come up with the present invention.

The firing jig of the present invention is a firing jig in which the bottom surface of the object to be fired is placed in contact with the mounting surface to perform heat treatment, so that the base portion and the tip surface serve as the mounting surface. The firing jig has a contact surface portion in which the bottom surface abuts on the mounting surface and a bottom surface when the object to be fired is placed on the mounting surface. The mounting surface is formed so as to have a non-contact surface portion that does not contact the mounting surface, the area of the contact surface portion is formed smaller than the area of the non-contact surface portion, and the pore ratio of the base is set to 1. When the coefficient of thermal expansion of the protruding portion is larger than 1 and 1.75 or less, and the value of the coefficient of thermal expansion of 1000 ° C. or lower of the protruding portion is larger than the value of the coefficient of thermal expansion of 1000 ° C. or lower at the base. When the coefficient of thermal expansion of the base is 1.48 or less and the value of the coefficient of thermal expansion of the base is larger than the value of the coefficient of thermal expansion of the protrusion. When the coefficient of thermal expansion of the protruding portion is 1, the value of the coefficient of thermal expansion of the base portion is 2.48 or less.

In the firing jig of the present invention, when the object to be fired is heat-treated, the area of the contact surface portion where the mounting surface of the firing jig contacts the object to be fired is smaller than the area of the non-contact surface portion. According to this configuration, when a gas such as a binder evaporates from the object to be fired during heat treatment, the gas diffuses into a space that becomes a non-contact surface portion larger than the contact surface portion. As a result, the high-concentration gas does not remain on the surface of the object to be fired, and it is possible to prevent problems caused by the gas remaining on the object to be fired.

Further, the firing jig of the present invention has a base portion and a protruding portion having a tip surface as a mounting surface. The protruding portion is more porous than the base portion, and the difference in the coefficient of thermal expansion between the base portion and the protruding portion is within a predetermined range. According to this configuration, the firing jig of the present invention has excellent thermal shock resistance.
In particular, since the porosity of the protruding portion forming the mounting surface is larger than that of the base portion, the binder can be transpired more uniformly. Further, by limiting the difference in the coefficient of thermal expansion, even if the firing jig is exposed to a high temperature, the occurrence of chipping and cracking at the boundary between the protruding portion and the base portion can be suppressed. That is, the protrusion is suppressed from falling off, and damage to the firing jig is suppressed.

It is a top view of the setter of the first form. It is sectional drawing of the setter of 1st form. It is a top view of the setter of the first form in a state where the object to be fired is placed. It is sectional drawing in the state which the object to be fired is placed on the setter of 1st form. It is a block diagram which shows the arrangement of the setter and the object to be fired at the time of heating the object to be fired in a heating furnace using the setter of 1st form. It is a top view of the setter of the second form. It is sectional drawing of the setter of the 3rd form. It is a top view of the setter of the 4th form. It is sectional drawing of the setter of 4th form. It is sectional drawing in the state which the object to be fired is placed on the setter of the 4th form. It is sectional drawing of the setter of the 5th form. It is a bottom view of the setter of the sixth form. It is a bottom view of the setter of another form of the sixth form. It is a top view of the setter of the 7th form. It is sectional drawing in the state which the object to be fired is placed on the setter of the 7th form. It is sectional drawing of the setter of the 8th form. It is sectional drawing of the setter of the 9th form. It is sectional drawing of the setter of the tenth form.

Hereinafter, an embodiment of the present invention will be described with reference to the embodiment in which the firing jig is used as a setter. The firing jig of the present invention is not limited to the setter, and can be applied to a firing jig used when heat-treating (firing) an object to be fired. Furthermore, the present invention is not limited to each embodiment, and can be implemented in various modifications. In addition, the following forms can be combined as appropriate.

[First form]
The setter 1 of this embodiment has a substantially plate shape as a whole, and the upper surface thereof is a mounting surface 1a on which the object 2 to be fired is placed. The mounting surface 1a, which is the upper surface of the setter 1 of the present embodiment, forms a flat surface on which the object to be fired can be placed as a whole. The setter 1 of this embodiment has a rectangular outer peripheral shape as a whole. The outer peripheral shape of the setter 1 indicates the shape when viewed from the upper surface. The outer peripheral shape of the setter 1 is not limited to the shape of this embodiment, and may be any shape.

As shown in FIGS. 1 and 2, the mounting surface 1a of the setter 1 of the present invention has a flat surface portion 10 and a recess 11 recessed from the flat surface portion 10. FIG. 1 is a top view, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

The flat surface portion 10 is located on the upper surface of the plate-shaped setter 1, and is a portion capable of contacting the bottom surface 2b of the object to be fired 2 when the object 2 to be fired is placed on the mounting surface 1a. Of the flat surface portion 10, the portion that comes into contact with the object to be fired 2 becomes the contact surface portion. The flat surface portion 10 is formed from a flat surface. The flat surface portion 10 is formed so as to spread along the horizontal direction when the setter 1 is used. The flat surface portion 10 may have fine irregularities formed on its surface. The fine unevenness means that the opening of the concave portion is 0.1 mm or less, and the unevenness formed by the conventional blasting process can be indicated.

The recess 11 is formed at a position that becomes a non-contact surface portion that does not abut on the bottom surface 2b of the object to be fired 2 when the object 2 to be fired is placed on the mounting surface 1a. The recess 11 is formed as a recess from the flat surface portion 10. The recess 11 is formed below the non-contact surface portion so as to face the non-contact surface portion.
As shown in FIG. 1, the recess 11 has a square (square shape in this embodiment) opening shape. The opening shape (outer peripheral shape of the opening) is not limited. Further, the opening shapes of the plurality of recesses 11 may be different. Further, the cross-sectional shape of the recess 11 (the outer peripheral shape of the cross section along the depth direction, the shape of the internal space of the recess 11 in the cross section shown in FIG. 2) is not limited.

In the setter 1 of the present embodiment, the plurality of recesses 11 are formed at predetermined intervals. The predetermined distance is the distance (shortest distance) between the recesses 11 on the mounting surface 1a. The length of the predetermined interval is not limited, but when the object to be fired 2 is placed on the mounting surface 1a, the area of the contact surface portion that comes into contact with the bottom surface 2b of the object to be fired 2 is the bottom surface 2b. It is formed so as to be smaller than the area of the non-contact surface portion that does not abut with. In the present embodiment, the predetermined interval (L1) is shorter than the length of one side (L2) of the rectangular recess 11, and L1 is preferably shorter than 50% of L2. L1 is more preferably shorter than 30% of L2 and even more preferably shorter than 20%.
In this embodiment, the plurality of recesses 11 having a rectangular opening shape are arranged at predetermined intervals. The distances between the plurality of recesses 11 may be the same, or the specific portions may have different lengths.

The cross-sectional shape of the recess 11 (the outer peripheral shape of the space in the cross section shown in FIG. 2) is not limited as long as it can diffuse the gas from the object 2 to be fired. As shown in FIG. 2, this embodiment has a concave cross section. That is, it has a wall portion 11c formed perpendicular to the flat surface portion 10 and a bottom surface portion 11a formed parallel to the flat surface portion 10.

The setter 1 of the present embodiment has a plate-shaped base portion 12 and a protruding portion 13 protruding from the base portion 12, as shown in a cross-sectional view in FIG. The setter 1 of this embodiment is formed so that the base portion 12 and the protruding portion 13 are integrated.
The base portion 12 is a plate-shaped member in which the protruding portion 13 projects from the surface of the setter 1 on the mounting surface 1a side. The base portion 12 has the same outer peripheral shape as the outer peripheral shape of the setter 1. The base portion 12 has a flat plate shape having a substantially constant thickness between the upper surface 12a and the lower surface 12b. In the setter 1 of the present embodiment, the upper surface 12a and the lower surface 12b spread out along the horizontal direction.

The projecting portion 13 is provided so as to project from the upper surface 12a of the base portion 12. A plurality of projecting portions 13 are provided on the base portion 12 at predetermined intervals. As shown in FIG. 2, the protruding portion 13 of the present embodiment has a plate shape having a constant thickness. The projecting portion 13 is provided so as to project in a direction perpendicular to the upper surface 12a of the base portion 12. As shown in FIG. 1, the protruding portion 13 is formed so that the tip surface 13a forms a grid pattern when the mounting surface 1a of the setter 1 is viewed.
In the protruding portion 13, the tip surface 13a in the protruding direction protruding from the base portion 12 serves as the mounting surface 1a of the setter 1. The tip surface 13a of the protrusion 13 is flat. The tip surface 13a of the protrusion 13 is located on the same plane.
The protrusion 13 partitions the recess 11. That is, the side surface of the protruding portion 13 partitions the space inside the recess 11.

The material of the setter 1 of this embodiment is not limited. Materials used in conventionally known setters can be used. For example, ceramics made of zirconia, alumina, mullite, spinel, silicon nitride, silicon carbide, cordierite, or a composite material thereof can be mentioned. Of these, when the object to be fired 2 is an electronic component, its contamination can be prevented, and therefore it is more preferably made of zirconia ceramics.
In the setter 1 of this embodiment, the entire base portion 12 and the protruding portion 13 are made of zirconia ceramics.

Zirconia does not only indicate that it is composed of zirconium oxide (ZrO ₂ ), but also includes partially stabilized zirconia in which elements such as yttrium, cerium, calcium, magnesium and rare earth elements are added to zirconium oxide. The ratio of the additive element in this 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 ), which is difficult to separate.

The overall density (apparent density) of the setter 1 of this embodiment is not limited. That is, it may be either a dense ceramic or a porous ceramic. The denser the setter 1, the higher the strength. Further, the more porous the material, the higher the thermal shock resistance.

The setter 1 of the present embodiment is formed so that the protruding portion 13 has a larger porosity than the base portion 12. That is, the protruding portion 13 is formed porously, and the base portion 12 is formed more densely than the protruding portion 13. The setter 1 of the present embodiment has a porosity of the protruding portion 13 larger than 1 and 1.75 or less when the porosity of the base 12 is 1.
Specifically, in the setter 1 of the present embodiment, the porosity of the base 12 is 10%, and the porosity of the protruding portion 13 is 15%. That is, when the porosity of the base 12 is 1, the porosity of the protruding portion 13 is 1.5 (it is included in the range larger than 1 and 1.75 or less).
The porosity of the setter 1 (base 12 and protrusion 13) can be measured by a known method. The porosity of the base 12 or the protrusion 13 of the setter 1 is the average porosity of each of the predetermined portions (base 12 or protrusion 13) to be measured.

In the setter 1 of the present embodiment, the protruding portion 13 and the base portion 12 may be formed of the same material or different materials. When the value of the coefficient of thermal expansion of the protruding portion 13 of 1000 ° C. or lower is larger than the value of the coefficient of thermal expansion of the base portion 12 of 1000 ° C. or lower, the setter 1 of the present embodiment sets the coefficient of thermal expansion of the base portion 12 to 1. When the value of the coefficient of thermal expansion of the protruding portion 13 is 2.48 or less and the value of the coefficient of thermal expansion of the base 12 is larger than the value of the coefficient of thermal expansion of the protruding portion 13, the protruding portion 13 When the coefficient of thermal expansion is 1, the value of the coefficient of thermal expansion of the base 12 is 2.48 or less.
The coefficient of thermal expansion of the setter 1 (base 12 and protrusion 13) can be measured by a known method.

The coefficient of thermal expansion of the typical ceramics forming the setter 1 of this embodiment at 1000 ° C. or lower is zirconia: 10.5 × ^10-6 / ° C., alumina: 7.9 × ^10-6 / ° C., mullite: 5. 8 × 10 ^-6 / ℃, spinel: 5.9 × 10 ^-6 / ℃, silicon nitride: 3.2 × 10 ^-6 / ℃, silicon carbide: 4.4 × 10 ^-6 / ℃.
Specifically, in the setter 1 of the present embodiment, the coefficient of thermal expansion of the base 12 is 5.8 × 10 ^-6 / ° C, and the coefficient of thermal expansion of the protruding portion 13 is 10.5 × 10 ^-6 / ° C. .. That is, when the coefficient of thermal expansion of the base portion 12 is 1, the coefficient of thermal expansion of the protruding portion 13 is 1.81 (included in the range of 2.48 or less).

When the base portion 12 and the protruding portion 13 are formed by combining different materials, the protruding portion 13 protrudes from the base portion 12, and the protruding portion 13 has a tip portion (tip surface) in the protruding direction. The porosity and coefficient of thermal expansion of the portion forming 13a) satisfy the above characteristics.

The production method of the setter 1 of the present embodiment is not limited. For example, it can be manufactured by using the following manufacturing method.
(First manufacturing method)
The setter 1 of the present embodiment is prepared by preparing a ceramic powder formed of a predetermined material so as to have a predetermined particle size distribution and to obtain a predetermined porosity, and the outer peripheral shape (predetermined shape) of the setter 1. It can be manufactured by molding so as to form a mold and firing the molded body (sintering the molded body).

For example, a fine powder composed of fine zirconia particles and a coarse powder composed of coarse zirconia particles are uniformly mixed to prepare a mixed powder. Here, an aqueous or organic solvent (preferably water) may be added to the mixed powder.

In this case, the particle size (average particle size, maximum particle size, minimum particle size) of the particles of each of the fine powder and the coarse powder, and the mixing ratio of each powder are determined by the target firing jig. It can be appropriately determined depending on the pore characteristics. For example, a coarse powder composed of coarse zirconia particles having an average particle size of 1 to 5 (μm) and a fine powder composed of fine zirconia particles having an average particle size of 0.1 to 0.55 (μm) are used. Can be manufactured.

Further, the ceramic powder may contain a pore-forming agent. In particular, when forming a porous body, the porosity can be adjusted by containing a pore-forming agent. The pore-forming agent disappears when fired to make the setter a porous body. The material of the pore-forming agent is not limited as long as it is fine particles (powder composed of) capable of forming fine pores in the setter 1 to be produced. Examples of the pore-forming agent include microbeads.

The microbeads are preferably made of at least one of an acrylic resin and a phenol resin. When the microbeads are made of a resin selected from these, the pores of the fired body can have a desired pore diameter (pore characteristics). Microbeads made of at least one of acrylic resin and phenol resin generate a smaller amount of heat when they are extinguished during firing than when the microbeads are made of carbon alone.
Further, the microbeads may be a medium substance or a hollow body having a hollow (closed or open space) inside.

The solvent and pore-forming agent contained in the ceramic powder are burnt or evaporated at a temperature lower than the firing temperature. That is, when these are used, it is preferable to perform a degreasing step of heating the molded product at a temperature lower than the firing temperature to eliminate (burn or evaporate) these components before firing (sintering) the molded product.

The mixed powder is molded into an integral shape having the base portion 12 and the protrusion portion 13 (that is, a shape having the flat surface portion 10 and the recess 11) to obtain a molded product. At this time, the protruding portion 13 is formed so as to contain a larger amount of the pore-forming agent. The molding method for producing the molded body is not limited, and a method of pressure molding using a molding die having a predetermined cavity can be used. More specifically, first, a mixed powder containing a large amount of pore-forming agent is charged into the portion where the protruding portion 13 of the molding die is molded, and then a small amount of the pore-forming agent is contained in the portion where the base portion 12 is molded. It can be manufactured by adding a mixed powder containing no pore-forming agent and pressure molding. Alternatively, a mixed powder containing a large amount of pore-forming agent is added to the portion where the protrusion 13 of the molding die is molded, and then pressure molding is performed to form the protrusion 13, and then a small amount is applied to the portion where the base 12 is molded. It can be manufactured by charging a mixed powder containing or not containing a pore-forming agent and then pressure-molding to integrally mold the protruding portion 13 and the base portion.
Here, the molding conditions such as the pressing force at the time of molding are determined by the molded product to be manufactured. That is, it is a condition that a desired molded product can be obtained.
The manufactured molded product is heated and fired (sintered). Heating conditions such as heating temperature and atmosphere are not limited.

(Second manufacturing method)
The setter 1 of the present embodiment is prepared by preparing a ceramic powder formed of a predetermined material so as to have a predetermined particle size distribution and to obtain a predetermined porosity, and to obtain the outer peripheral shapes of the base portion 12 and the protruding portion 13. It can be manufactured by molding each so as to form (predetermined shape), firing the molded body (sintering the molded body), and joining (adhering) the molded body.
Similar to the first production method described above, a mixed powder for producing the base 12 and a mixed powder for producing the protrusion 13 are prepared. Then, each mixed powder is put into a cavity having a shape corresponding to the base portion 12 or the protruding portion 13, and molded. Then, the molded product can be manufactured by joining the molded products with an adhesive and firing the molded product in the same manner as in the first manufacturing method.
Alternatively, the molded bodies of the base portion 12 and the protruding portion 13 can be fired and then joined to produce the molded product.

(Action effect)
The setter 1 of this embodiment can be used, for example, as follows.
As shown in FIGS. 3 to 5, the setter 1 of the present embodiment is placed in the heating furnace 3 with the object to be fired 2 placed on the mounting surface 1a, and the heating furnace 3 is heated to be covered. The fired product 2 is heat-treated (baked, sintered). FIG. 3 is an enlarged top view of a state in which the object to be fired 2 is placed on the mounting surface 1a, and FIG. 4 is an enlarged partial cross-sectional view taken along line IV-IV in FIG.

The object 2 to be fired, which is subjected to heat treatment by the setter 1 of the present embodiment, has a bottom surface 2b that faces the mounting surface 1a and is in contact with a part thereof, and is plate-shaped, columnar, block-shaped (lump-shaped), or It has a predetermined shape such as a pipe shape. The object to be fired 2 is preferably a molded product obtained by molding a powder raw material into a predetermined shape.

The shape of the object 2 to be fired is not limited. Further, the setter 1 is provided with a contact surface portion 2c and a non-contact surface portion 2d that come into contact with the mounting surface 1a when mounted on the mounting surface 1a. That is, as long as the bottom surface 2b of the object to be fired 2 has a shape larger than the recess 11 of the setter 1, the size is not limited.

As shown in FIG. 3, the object 2 to be fired has a square plate shape having a side (L3). The length of one side of the square (L3) is longer than the length of one side of the recess 11 (L2). Therefore, at least a part of the object 2 to be fired placed on the mounting surface 1a is placed on the flat surface portion 10 (tip surface 13a). It is placed in the recess 11 without falling.

When the object to be fired 2 is placed on the mounting surface 1a of the setter 1 of the present embodiment, the bottom surface 2b of the object to be fired 2 comes into contact with the mounting surface 1a. The mounting surface 1a is formed so as to have the flat surface portion 10 and the concave portion 11, and the bottom surface 2b of the object to be fired 2 has a portion in contact with the flat surface portion 10 as a contact surface portion 2c and a portion corresponding to the concave portion 11. Is the non-contact surface portion 2d. The contact surface portion 2c of the object to be fired 2 corresponds to the contact surface portion of the setter 1 in which the bottom surface 2b of the object to be fired 2 abuts on the mounting surface 1a of the setter 1, and the non-contact surface portion 2d of the object to be fired 2 is , Corresponds to the non-contact surface portion of the setter 1. Hereinafter, the contact surface portion and the non-contact surface portion of the mounting surface 1a of the setter 1 will be described with reference to the contact surface portion 2c and the non-contact surface portion 2d of the object to be fired 2.
As shown in FIG. 3, each side of the square object to be fired 2 is placed in a direction parallel to the extending direction of the flat surface portion 10.

In this state, as shown in the cross-sectional view in FIG. 4, the bottom surface 2b of the object to be fired 2 does not come into contact with the mounting surface 1a (the flat surface portion 10) and the contact surface portion 2c, which is in contact with the mounting surface 1a. The non-contact surface portion 2d (corresponding to the recess 11) is provided, and the area of the contact surface portion 2c is smaller than the area of the non-contact surface portion 2d. This area comparison can be performed using L1, L2, and L3. That is, as shown in FIG. 4, the area of the contact surface portion 2c is used by L1 of the length (width) of the flat surface portion 10. The area of the non-contact surface portion 2d is a length (L3-L1) obtained by subtracting L1 from the length L3 of one side of the bottom surface 2b of the object to be fired 2. Since L3 is longer than L2 and L1 is shorter than 50% of L2, the relationship is (L3-L1)>(L2-L1)> (2 × L1-L1) = L1. That is, the area of the non-contact surface portion 2d is larger than the area of the contact surface portion 2c.
In this state, as shown in FIG. 5, the object to be fired 2 is heat-treated (baked or sintered) in the heating furnace 3.

As shown above, in the setter 1 of the present embodiment, when the object to be fired 2 is heat-treated, the area of the contact surface portion 2c where the mounting surface 1a of the setter 1 comes into contact with the object to be fired 2 is the non-contact surface portion 2d. Is smaller than the area of. According to this configuration, even if a gas such as a binder evaporates from the object 2 to be fired during the heat treatment, the gas diffuses into the space in the recess 11 forming the non-contact surface portion 2d larger than the contact surface portion 2c. As a result, high-concentration gas does not remain (exist) near the surface of the object to be fired 2, and it is possible to prevent problems caused by the gas remaining on the object to be fired 2.

Further, the setter 1 of the present embodiment has a base portion 12 and a protruding portion 13 protruding from the upper surface 12a of the base portion 12 so that the tip end surface 13a becomes the mounting surface 1a.
When the porosity of the base 12 is 1, the porosity of the protruding portion 13 is 1.5 (that is, it is larger than 1 and within the range of 1.75 or less). According to this configuration, the ratio of the porosity of the base portion 12 and the protruding portion 13 is within a predetermined range, and the protruding portion 13 is made of a more porous material than the base portion 12. Then, the protruding portion 13 of the setter 1 of the present embodiment is excellent in thermal shock resistance.
Further, in the setter 1 of the present embodiment, since the porosity of the protruding portion 13 forming the mounting surface 1a is larger than the porosity of the base portion 12, even if gas such as a binder evaporates from the object 2 to be fired during the heat treatment. This gas evaporates more uniformly.

In addition, in the setter 1 of the present embodiment, the value of the base 12 protrudes when the value of the coefficient of thermal expansion of 1000 ° C. or lower of the base 12 is compared with the value of the coefficient of thermal expansion of 1000 ° C. or lower of the protruding portion 13. It is larger than the value of unit 13. Then, when the coefficient of thermal expansion of the base portion 12 is 1, the value of the coefficient of thermal expansion of the protruding portion 13 is 1.81 (that is, 2.48 or less). According to this configuration, the difference in the coefficient of thermal expansion between the base portion 12 and the protruding portion 13 is small. Therefore, even if the heat treatment is performed using the setter 1, it is possible to prevent damage to occur at the portion where the base portion 12 and the protruding portion 13 are connected. That is, it is superior in thermal shock resistance.
Further, in the setter 1 of the present embodiment, the difference in the coefficient of thermal expansion between the base portion 12 and the protruding portion 13 is within a predetermined range. According to this configuration, even if the setter 1 is exposed to a high temperature during heat treatment, the occurrence of chips and cracks at the boundary between the base portion 12 and the protruding portion 13 can be suppressed. That is, the protrusion 13 is prevented from falling off from the base 12, and the setter 1 is suppressed from being damaged.

In the setter 1 of the present embodiment, the flat surface portion 10 corresponding to the contact surface portion 2c is formed in a flat surface, the recess 11 corresponding to the non-contact surface portion 2d is formed in a recessed state from the flat surface portion 10, and the non-contact surface portion 2d is formed. It is formed by the recess 11. According to this configuration, the flat flat portion 10 can support the object 2 to be fired by surface contact. That is, the flat surface portion 10 and the object to be fired 2 come into surface contact with each other, so that pressure concentration does not occur on the contact surface portion 2c. Therefore, it is possible to prevent the object 2 to be fired from being deformed during firing.

When the bottom surface 2b of the object to be fired 2 is much larger, that is, when the object to be fired 2 is placed on the mounting surface 1a of the setter 1 of the present embodiment, the bottom surface 2b of the object to be fired 2 has a plurality of recesses 11. Even when the coating is possible, the area of the non-contact surface portion 2d is larger than the area of the contact surface portion 2c. That is, the above effect can be exhibited.

[Second form]
This form is the same setter 1 as the first form except that the shape of the recess 11 is different.
The setter 1 of the present embodiment is the same as the setter 1 of the first embodiment except that the recess 11 is a groove. In the setter 1 of the present embodiment, a plurality of recesses 11 are connected to form a groove in the setter of the first embodiment. The setter 1 of this embodiment is shown in a top view in FIG.

The setter 1 of the present embodiment has the same cross-sectional shape of the groove forming the recess 11 (inner peripheral shape in the cross section perpendicular to the extending direction of the groove) as in the first form. The length of the groove forming the recess 11 is not limited and may be any length. Further, the end portion in the length direction of the groove may extend to the end portion of the setter 1. That is, the end portion in the length direction of the groove may be opened on the side surface of the plate-shaped setter 1.
The setter 1 of the present embodiment is the same as the setter 1 of the first embodiment except that the opening shape of the recess 11 on the mounting surface 1a is different, and exhibits the same effect.

[Third form]
This form is the same setter 1 as the second form except that the cross-sectional shape of the recess 11 is different (that is, the cross-sectional shape of the protrusion 13 is different).
The setter 1 of the present embodiment is the same as the setter 1 of the second embodiment except that the cross-sectional shape of the recess 11 is substantially U-shaped. That is, the bottom surface portion 11a of the recess 11 has a shape curved in the depth direction. The cross-sectional shape of the recess 11 of the setter 1 of this embodiment is shown in FIG.
As shown in FIG. 7, the protruding portion 13 is formed so that the connecting portion connected to the base portion 12 has a smooth curved shape.
The setter 1 of the present embodiment is the same as the second form except that the cross-sectional shape of the groove of the recess 11 and the cross-sectional shape of the protruding portion 13 are different, and exhibit the same effect.

[Fourth form]
This embodiment is the same setter 1 as the first embodiment except that a through hole 14 is further formed in the recess 11.
The setter 1 of the present embodiment is the same as the setter 1 of the first embodiment except that a through hole 14 penetrating the plate-shaped setter 1 is formed in the bottom surface portion 11a of the recess 11. The upper surface of the setter 1 of this embodiment is shown in FIG. 8, and an enlarged partial cross-sectional view taken along the line IX-IX in FIG. 8 is shown in FIG.

In the setter 1 of this embodiment, a through hole 14 is formed in the bottom surface portion 11a of the recess 11. The through hole 14 extends from the bottom surface portion 11a in the plate thickness direction of the base portion 12 of the setter 1 and is formed so as to penetrate the base portion 12. The through hole 14 has a circular shape (inner peripheral shape) in a cross section perpendicular to the plate thickness direction of the base portion 12 which is smaller than that of the bottom surface portion 11a. The cross-sectional shape of the through hole 14 is not limited, and may be a square shape, a polygonal shape, an elliptical shape, or the like. Further, the through hole 14 of the present embodiment is formed with a constant cross section, but is not limited to this shape. It may have a shape in which the diameter changes in the thickness direction (for example, a shape in which the diameter changes stepwise, a shape in which the diameter gradually changes).
The setter 1 of the present embodiment is the same as the setter 1 of the first embodiment except that a through hole 14 penetrating the base portion 12 is formed in the bottom surface portion 11a of the recess 11, and exhibits the same effect.

The setter 1 of the present embodiment has a configuration in which the recess 11 is provided with a through hole 14 (communication portion) in the bottom surface portion 11a (bottom surface) thereof to communicate with the outside by penetrating the base portion 12. According to this configuration, the gas from the object to be fired 2 can diffuse to the outside through the recess 11 and the through hole 14. As shown in FIG. 10, even when the object to be fired 2 completely covers the opening of the recess 11, the plate-shaped setter 1 does not leave the gas from the object 2 to be fired in the recess 11. Can escape from the mounting surface 1a to the back surface 1b side and diffuse to the outside.

[Fifth form]
This form is the same setter 1 as the fourth form except that the cross-sectional shape of the through hole 14 is different.
The setter 1 of the present embodiment is the same as the setter 1 of the fourth embodiment except that the cross-sectional shape of the through hole 14 is the same as the shape of the opening of the recess 11. The setter 1 of the present embodiment has a configuration formed of a protruding portion 13 (corresponding portion) and a base portion 12 (corresponding portion). The base portion 12 (corresponding portion) has a shape corresponding to the protruding portion 13 (corresponding portion). In the setter 1 of the present embodiment, the base portion 12 (corresponding portion) and the protruding portion 13 (corresponding portion) have the same shape in which the through hole 14 is formed, and the respective portions 12 and 13 (corresponding portions) have the same shape. ) Have an integrally formed structure. In the setter 1 of the present embodiment, the porosity and the coefficient of thermal expansion of the respective portions 12 and 13 (corresponding portions) are adjusted in the same manner as the base portion 12 or the protruding portion 13 of the fourth form (that is, the first form). There is. In the setter 1 of the present embodiment, the base portion 12 forms the back surface 1b of the setter 1. In the setter 1 of the present embodiment, the thickness (or the ratio of the thickness) of each of the portions 12 and 13 (corresponding portions) is set in the same manner as in the fourth embodiment. The thickness of each part 12 and 13 (corresponding part) can be arbitrarily set within a range in which the total is the thickness of the setter 1. The cross-sectional shape of the setter 1 in the vicinity of the through hole 14 of the present embodiment is shown in FIG. In FIG. 11, the boundary between the protruding portion 13 (corresponding portion) and the base portion 12 (corresponding portion) is shown by a broken line in the cross-sectional portion and a solid line in the inner peripheral surface of the wall portion 11c. This boundary may appear to disappear.

In the setter 1 of the present embodiment, the recess 11 and the through hole 14 are integrated holes (holes having a constant hole diameter and hole shape), and the integrated holes are from the upper surface (mounting surface 1a) to the back surface 1b of the setter 1. The setter 1 is the same as the fourth form except that it is formed so as to penetrate the setter 1 in the thickness direction, and exhibits the same effect as the fourth form.

[6th form]
This form is the same setter 1 as the fourth form except that the groove 15 is further formed on the back surface 1b.
Similar to the fourth embodiment, the setter 1 of the present embodiment has a through hole 14 having one end opened in the bottom surface portion 11a of the recess 11. A plurality of grooves 15 are formed on the back surface 1b of the setter 1. Through holes 14 are opened in each of the grooves 15. The plurality of through holes 14 are provided with openings on the back surface 1b side of the setter 1 in any of the grooves 15. The back surface 1b of the setter 1 of this embodiment is shown in FIG.

The cross-sectional shape of the groove 15 is not limited. Here, the cross-sectional shape of the groove 15 is a cross-sectional shape (shape of the inner peripheral surface) in a direction (vertical direction in FIG. 12) perpendicular to the extending direction (horizontal direction in FIG. 12). The cross-sectional shape of the groove 15 in the setter 1 of this embodiment is a square shape (a shape having a concave cross-sectional shape). In the cross-sectional shape of the groove 15, the through hole 14 is opened on the surface of the setter 1 located on the mounting surface 1a side (the bottom surface when the groove 15 is viewed from the back surface 1b side). The cross-sectional shape of the groove 15 of the present embodiment is rectangular, but the cross-sectional shape is not limited to this shape. For example, it may have a curved shape such as a triangular shape or a semicircular shape.

The setter 1 of the present embodiment is the same as the setter 1 of the fourth embodiment except that the openings on the back surface 1b side of the plurality of through holes 14 are opened in the grooves 15, and the same effect is exhibited.
Further, in the setter 1 of the present embodiment, the gas that has passed through the through hole 14 flows through the groove 15 and diffuses to the outside from the side surface of the setter 1, so that the gas can be reliably diffused to the outside.

In this embodiment, as shown in FIG. 12, the groove 15 is formed along the lateral direction in FIG. 12 (the direction in which the plurality of recesses 11 are arranged, the direction parallel to the lateral direction of the rectangular setter 1). It is formed to stretch, but is not limited to this pattern. For example, as shown in FIG. 13, it may be formed along an oblique direction (a licking direction in which a plurality of recesses 11 are arranged, a direction parallel to the diagonal direction of the rectangular setter 1).

Further, in the present embodiment, the width of the opening (the vertical width in FIG. 12) at which the groove 15 opens on the back surface 1b side (specifically, the lower surface 12b of the base portion 12) is wider than the diameter of the through hole 14. The shape is not limited to this shape. That is, the width of the opening of the groove 15 may be the same as or narrower than the diameter of the through hole 14.
Further, in the present embodiment, a plurality of grooves 15 are formed side by side in a state of extending along the lateral direction (or diagonal direction), but the shape is not limited to this. At least two grooves may be formed so as to intersect and form a cross shape.
Further, in this embodiment, the groove 15 is formed in a shape provided on the lower surface 12b of the base portion 12, but may be provided on the mounting surface 1a side. This shape is, for example, a shape in which a plurality of recesses 11 arranged adjacent to each other are integrated in the first form.

[7th form]
In the setter 1 of this embodiment, the configuration not particularly mentioned is the same as that of the first embodiment.
The setter 1 of this embodiment has a substantially plate shape in which the upper surface is a mounting surface 1a on which the object to be fired is placed. The mounting surface 1a on the upper surface of the setter 1 of the present embodiment forms a flat surface on which the object to be fired can be placed as a whole. The setter 1 of this embodiment has a rectangular outer peripheral shape as a whole. The outer peripheral shape of the setter 1 is not limited.

As shown in FIGS. 14 to 15, the mounting surface 1a of the setter 1 of the present invention has a base portion 16 and a protruding portion 17 protruding from the base portion 16. FIG. 14 is a top view, and FIG. 15 is an enlarged partial cross-sectional view taken along the line XV-XV in FIG.
The base portion 16 is a plate-shaped member provided on the mounting surface 1a side of the setter 1 and the protruding portion 17 projects from the surface thereof. The base 16 has the same configuration as the base 12 of the first form.

The protruding portion 17 is provided so as to project from the upper surface 16a of the base portion 16 (provided to stand upright in the plate thickness direction of the base portion 16). A plurality of projecting portions 17 are provided on the upper surface 16a of the base portion 16 at predetermined intervals. In this embodiment, as shown in FIG. 14, they are provided at equal intervals with a predetermined interval.

As shown in FIG. 14, the protruding portion 17 in the present embodiment has a columnar shape having a constant cross section whose axial direction extends along the plate thickness direction of the setter 1. In the present embodiment, the cross-sectional shape of the protruding portion 17 in the cross section perpendicular to the axial direction is circular (that is, the protruding portion 17 has a cylindrical shape), but this cross-sectional shape is not limited. For example, a square or rectangular square shape, a polygonal shape, an elliptical shape, or the like can be mentioned.

In the protruding portion 17, the tip surface 17a in the protruding direction protruding from the upper surface 16a of the base portion 16 serves as the mounting surface 1a of the setter 1. The tip surface 17a of the protruding portion 17 is flat. The tip surfaces 17a of the plurality of protrusions 17 are located on the same plane.

In the setter 1 of the present embodiment, if the tip surfaces 17a of the plurality of projecting portions 17 are formed so as to be located on the same plane, the shape of the base portion 16 in the plate thickness direction is not limited. It is preferable that the upper surface of the base portion 16 is provided substantially parallel to the mounting surface 1a.

In the setter 1 of the present embodiment, the plurality of protruding portions 17 are formed at predetermined intervals. Although the predetermined interval is not limited, when the object to be fired 2 is placed on the mounting surface 1a, the area of the contact surface portion 2c that comes into contact with the bottom surface 2b of the object to be fired 2 corresponds to the bottom surface 2b. It is formed so as to be smaller than the area of the non-contact surface portion 2d that does not contact. In the present embodiment, the distance (L4) between the axes of the two adjacent protrusions 17 (corresponding to the central axis of the columnar protrusions 17) is longer than the outer diameter (L5) of the columnar protrusions 17.
In the setter 1 of the present embodiment, the area of the contact surface portion 2c is smaller than the area of the non-contact surface portion 2d. Therefore, the same effect as that of the first form can be exhibited.

The setter 1 of the present embodiment has a plate-shaped base portion 16 and a protruding portion 17 that protrudes from the upper surface 16a of the base portion 16 and whose tip portion serves as a contact surface portion. According to this configuration, a large space can be set between the plurality of protrusions 17, and the gas diffuses into this large space. As a result, the above effect can be more reliably exhibited.

In the setter 1 of this embodiment, the protruding portion 17 has a columnar shape. According to this configuration, the contact area between the tip surface 17a of the protruding portion 17 and the object to be fired 2 can be increased, and the above effect can be more reliably exhibited.

[8th form]
This form is the same setter 1 as the seventh form except that the shape of the protruding portion 17 is different.
As shown in FIG. 16 in cross section, the diameter of the protruding portion 17 of the setter 1 of the present embodiment is gradually reduced from the base end (base portion 16) to the tip end (tip surface 17a). That is, as shown in FIG. 16, it has a truncated cone shape with a trapezoidal cross section.
The setter 1 of the present embodiment exhibits the same effect as that of the seventh embodiment because the contact surface portion 2c and the non-contact surface portion 2d of the mounting surface 1a and the object to be fired 2 have the same configuration.

The setter 1 of the present embodiment has a columnar shape having a tapered shape in which the protruding portion 17 is reduced in diameter from the base end (base portion 16) to the tip end (tip surface 17a). According to this configuration, the strength of the protruding portion 17 is increased, and the above effect can be more reliably exhibited.

In the setter 1 of the present embodiment, the protrusion 17 is provided at a distance from another protrusion 17, but the setter 1 is not limited to this configuration. For example, the base end (base portion 16) of the protruding portion may be in contact with the base end (base portion 16) of another protruding portion 17.
Further, in the present embodiment, the cross-sectional shape of the protruding portion 17 is a truncated cone shape, but it may have a polygonal truncated cone shape.

[9th form]
This form is the same setter 1 as the seventh form except that the shape of the protruding portion 17 is different.
As shown in FIG. 17, the diameter of the protruding portion 17 of the setter 1 of the present embodiment gradually decreases as the cross section proceeds from the base end (base portion 16 side) to the tip end (tip surface 17a side), and the tip end. Is the point. That is, the protruding portion 17 has a conical shape (the cross-sectional shape of the cross section along the protruding direction shown in FIG. 17 is triangular).
The setter 1 of this embodiment exerts the same effect as that of the seventh embodiment.

The setter 1 of the present embodiment has a tapered conical shape in which the protruding portion 17 is reduced in diameter from the base end (base portion 16) to the tip end (tip surface 17a). According to this configuration, the contact surface portion 2c where the protrusion 17 and the object to be fired 2 come into contact with each other can be made as small as possible. Then, the gas from the object to be fired 2 immediately diffuses and does not remain in the vicinity of the object to be fired 2. That is, the setter 1 of the present embodiment has higher diffusibility of gas from the object to be fired 2.

[10th form]
This form is the same setter 1 as the ninth form except that the shape of the protruding portion 17 is different.
As shown in FIG. 18, the diameter of the protruding portion 17 of the setter 1 of the present embodiment gradually decreases from the base end (base portion 16) to the tip end (tip surface 17a), and the tip end becomes a point. It has a hemispherical shape. That is, the protruding portion 17 has a hemispherical shape (the outer peripheral surface forms an arc surface, and the cross section has a semicircular shape).
The setter 1 of this embodiment exerts the same effect as that of the ninth embodiment.

The setter 1 of the present embodiment has a tapered hemispherical shape in which the protruding portion 17 is reduced in diameter from the base end (base portion 16) to the tip end (tip surface 17a). According to this configuration, the bottom surface 2b of the object to be fired 2 circumscribes the tip of the protrusion 17 (in the cross-sectional view, the bottom surface 2b forms a tangent line at the tip of the semicircular protrusion 17).

Even when firing in this state, the object to be fired 2 may undergo a volume change (shrinkage). In particular, shrinkage occurs during sintering. In this embodiment, even if the object to be fired 2 shrinks on the mounting surface 1a, the tip of the projecting portion 17 has a smooth shape (hemispherical shape), so that the shrinkage of the object to be fired 2 is hindered by the projecting portion 17. Not done. That is, even if the object 2 to be fired undergoes a volume change during firing, it shrinks smoothly on the mounting surface 1a, so that the decrease in dimensional accuracy of the object 2 to be fired can be suppressed. That is, a product having a desired shape (processed product after heat treatment) can be obtained.

1: Setter 10: Flat part 11: Recessed part 12, 16: Base part 13, 17: Protruding part 2: Object to be fired 3: Heating furnace

Claims (6)

A firing jig that performs heat treatment by placing the bottom surface of the object to be fired in contact with the mounting surface.
It has a base portion and a protruding portion protruding from the surface of the base portion so that the tip surface serves as the mounting surface.
The firing jig has a contact surface portion where the bottom surface comes into contact with the mounting surface when the object to be fired is placed on the mounting surface, and the bottom surface does not abut against the mounting surface. The mounting surface is formed so as to have a contact surface portion.
The area of the contact surface portion is formed smaller than the area of the non-contact surface portion.
When the porosity of the base is 1, the porosity of the protruding portion is greater than 1 and 1.75 or less.
When the value of the coefficient of thermal expansion of 1000 ° C. or lower of the protrusion is larger than the value of the coefficient of thermal expansion of 1000 ° C. or lower of the base, the heat of the protrusion is set to 1 when the coefficient of thermal expansion of the base is 1. The value of the coefficient of expansion is 2.48 or less,
When the value of the coefficient of thermal expansion of the base is larger than the value of the coefficient of thermal expansion of the protruding portion, the value of the coefficient of thermal expansion of the base is 2.48 when the coefficient of thermal expansion of the protruding portion is 1. A firing jig characterized by the following. The firing jig according to claim 1, wherein the bottom surface of the object to be fired is a flat surface. The firing jig according to any one of claims 1 to 2, wherein a recess is formed below the non-contact surface portion. The firing jig according to claim 3, wherein the recess has a communication portion that communicates with the outside. The firing jig according to any one of claims 1 to 2, wherein the protruding portion has a columnar shape . The firing jig according to claim 5, wherein the protruding portion has a tapered shape whose diameter is reduced from the base portion to the tip portion.

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