JP2021042097A - Ceramic sintered body - Google Patents

Abstract

To provide a ceramic sintered body capable of forming a uniform temperature distribution on a placement surface.SOLUTION: The present invention provides a ceramic sintered body 10 that includes a placement surface F on which a substrate is placed, in which: the ceramics sintered body 10 is provided with a flow path 4 extending along a placement surface F at a position away from the placement surface F and flowing a medium through it; and a thermal conductivity of at least a portion of the flow path upper area X is smaller than a thermal conductivity of at least a portion of other area Y of the ceramic sintered body 10 adjacent to the flow path upper area X in a direction along the placement surface F, where a portion between the flow path 4 and the placement surface F of the ceramic sintered body 10 in a direction perpendicular to the placement surface F is defined as the flow path upper area X.SELECTED DRAWING: Figure 2

Description

The present invention relates to a ceramic sintered body.

Conventionally, a ceramic sintered body having a hollow structure as a medium flow path and being integrated without having an interface is known (see, for example, Patent Document 1).

In Patent Document 1, a method for manufacturing a flat ceramic member having a hollow portion and being integrally fired, wherein a mold is filled with ceramic powder and a first press molding is performed, and a first step. A step of providing a core whose main body is made of resin on one main surface side of the press-molded body, a step of filling ceramic powder from above the core and performing a second press molding, and a second press by heating. It includes a step of removing the resin of the core body from the side surface of the molded body and a step of firing a second press molded body from which the resin has been removed.

In this way, by removing the resin core body from the molded body of the ceramic powder sufficiently pressed in two steps to form a hollow structure, an integrated ceramic firing having a hollow structure and no interface is performed. The union can be manufactured at low cost.

Japanese Unexamined Patent Publication No. 2014-233883

When a ceramics sintered body having a flow path through which a cooling medium can flow, for example, is used as a base provided with a mounting surface on which a substrate such as a wafer or an electrostatic chuck is mounted, the ceramics sintered body is used. The distance from the mounting surface of the body to the flow path goes straight down depending on the part where the flow path is located directly under the mounting surface and the part where the flow path is not located directly under the mounting surface. The distance differs depending on whether it is a distance or an obliquely inclined distance, and the distance from the mounting surface to the flow path differs depending on the position of the mounting surface. Therefore, there is a difference in the thermal resistance from the mounting surface of the ceramic sintered body to the flow path.

The fact that the thermal resistance differs depending on the position of the mounting surface of the ceramics sintered body means that when the amount of heat uniformly input to the ceramics sintered body is transferred to the medium flowing through the flow path, the flow path exists directly below. A temperature difference occurs between the mounting surface portion and the portion other than the mounting surface portion.

Therefore, the cooling effect of the medium flowing in the flow path of the ceramic sintered body does not appear uniformly on the mounting surface, which affects the temperature distribution of the substrate mounted on the ceramic sintered body, and the substrate temperature becomes non-uniform. There is a risk of becoming.

In view of the above points, it is an object of the present invention to provide a ceramic sintered body capable of forming a uniform temperature distribution on a mounting surface.

[1] In order to achieve the above object, the present invention
A ceramics sintered body having a mounting surface on which a substrate is mounted.
The ceramics sintered body extends along the previously described surface at a position away from the previously described surface and includes a flow path through which the medium flows.
The portion of the ceramic sintered body between the flow path and the above-mentioned mounting surface in the vertical direction of the above-mentioned mounting surface is defined as a flow path upper region.
The thermal conductivity of at least a part of the flow path upper region is higher than the thermal conductivity of at least a part of the other region adjacent to the flow path upper region of the ceramic sintered body in the direction along the above-mentioned mounting surface. Is also small.

According to the present invention, the thermal conductivity of at least a part of the flow path upper region is at least a part of the other region of the ceramics sintered body adjacent to the flow path upper region in the direction along the above-mentioned mounting surface. Since it is smaller than the thermal conductivity of the above, it is possible to provide a ceramics sintered body capable of forming a uniform temperature distribution on the mounting surface.

[2] Further, in the present invention, it is preferable that the bulk density of at least a part of the flow path upper region is smaller than the bulk density of at least a part of the other region.

[3] Further, in the present invention, it is preferable that the ceramic sintered body contains silicon carbide as a main component. In the present invention, the term "silicon carbide as a main component" means that the ceramic sintered body contains 50% by mass or more of silicon carbide.

The flowchart which shows the manufacturing method of the ceramics sintered body which concerns on 1st Embodiment of this invention. FIG. 2A is a schematic cross-sectional view showing the first and second SiC calcined bodies. FIG. 2B is a schematic cross-sectional view showing a state in which the first and second SiC calcined bodies are laminated. FIG. 2C is a schematic cross-sectional view showing a ceramic sintered body. The flowchart which shows the manufacturing method of the ceramics sintered body which concerns on 2nd Embodiment of this invention. FIG. 4A is a schematic cross-sectional view showing the first to third SiC calcined bodies. FIG. 4B is a schematic cross-sectional view showing a state in which the first to third SiC calcined bodies are laminated. FIG. 4C is a schematic cross-sectional view showing a ceramic sintered body. FIG. 5A is a schematic cross-sectional view showing the first and second SiC calcined bodies in Examples 8, 9 and 11. FIG. 5B is a schematic cross-sectional view showing a state in which the first and second SiC calcined bodies are laminated. FIG. 5C is a schematic cross-sectional view showing a ceramic sintered body.

The ceramic sintered body 10 according to the first embodiment of the present invention will be described with reference to the drawings. It should be noted that the drawings are schematically shown for clarifying the ceramic sintered body 10 and its constituent elements, and do not represent the actual ratio, and the directions such as up and down are merely examples.

As shown in FIG. 1, the ceramic sintered body 10 of the first embodiment has a first SiC calcined body acquisition step STEP1, a second SiC calcined body acquisition step STEP2, a first plane forming step STEP3, and a first. 2. The flat surface forming step STEP4, the recess forming step STEP5, the laminating step STEP6, and the firing step STEP7 are provided.

In the first SiC calcined body acquisition step STEP1, referring to FIG. 2A, the first SiC molded body is calcined at a temperature of 1200 ° C. or higher and 1900 ° C. or lower to obtain the first SiC calcined body 1. .. In the second SiC calcined body acquisition step STEP2, the second SiC molded body is calcined at a temperature of 1200 ° C. or higher and 1900 ° C. or lower to obtain a second SiC calcined body 2. The calcining temperatures in the first SiC calcined body acquisition step STEP1 and the second SiC calcined body acquisition step STEP2 may be the same or different.

In the first SiC calcined body acquisition step STEP1 and the second SiC calcined body acquisition step STEP2, two SiC molded bodies obtained by molding SiC (silicon carbide) powder are calcined to perform the first and second operations. SiC calcined bodies 1 and 2 are formed. For example, additives such as a sintering aid and a binder are appropriately added to and mixed with SiC powder to prepare a molding raw material, and pressure molding is performed using this molding material to form two SiC molded bodies. To do.

The SiC powder is preferably of high purity, and the purity is preferably 96% or more, more preferably 98% or more. The average particle size of the SiC powder is preferably 0.1 μm or more and 1.0 μm or less, and more preferably 0.3 μm or more and 0.8 μm or less.

The mixing method may be either wet or dry, and for example, a mixer such as a ball mill or a vibration mill can be used. Further, a SiC granule may be prepared by adding a sintering aid or the like to the SiC powder, and a SiC molded body may be formed by pressure molding using the SiC granule to which an additive such as a binder is added. .. As the molding method, for example, a known method such as uniaxial pressure molding or cold isostatic pressing (CIP) method may be used.

The SiC molded body is heated at a temperature of 900 ° C. or higher and lower than 1200 ° C. to obtain a SiC degreased body, and then the SiC degreased body is heated at a temperature of 1200 ° C. or higher and 1900 ° C. or lower to obtain the first and second defatted bodies. SiC calcined bodies 1 and 2 may be obtained. Further, the first and second SiC calcined bodies 1 and 2 may be obtained by heating the SiC molded body while continuously raising the temperature to a temperature of 1200 ° C. or higher and 1900 ° C. or lower.

In the first plane forming step STEP3, the first plane 1a is formed on the first SiC calcined body 1. In the second plane forming step STEP4, the second plane 2a is formed on the second SiC calcined body 2. The first plane 1a and the second plane 2a are surfaces that come into contact with each other in the laminating step STEP6.

Using a surface grinder such as an NC lathe or MC processing machine or a lapping processing machine, for example, the surface roughness Ra is preferably 0.15 μm or more and 0.8 μm or less, more preferably 0.15 μm or more and 0.4 μm or less. The first and second planes 1a and 2a are formed by grinding and polishing as necessary.

In the recess forming step STEP5, the recess 3 is formed on at least one of the first plane 1a and the second plane 2a. The recess 3 is for forming the flow path 4, and is formed by grinding or the like so as to dig from either or both of the first flat surface 1a and the second flat surface 2a.

In the first plane forming step STEP3 or the second plane forming step STEP4, the first or second planes 1a and 2a are left without polishing or only roughly ground, and the recess forming step STEP5 After forming the recess 3 in the above, the first or second flat surfaces 1a and 2a may be polished or finished by grinding.

When the recesses 3 are formed so as to be dug from both the first and second planes 1a and 2a, these recesses 3 are brought into contact with the first and second planes 1a and 2a in the laminating step STEP5. Occasionally, it may be integrated to form the flow path 4, but it may be closed by another plane. Further, it is preferable that the boundary portion between the first and second flat surfaces 1a and 2a and the recess 3 and the bottom corner portion of the recess 3 are chamfered such as an R surface and a C surface.

Further, in the first flat surface forming step STEP3, the second flat surface forming step STEP4, or the concave portion forming step STEP5, the first flat surface 1a, the second flat surface 2a, or the concave portion 3 is formed by dry grinding or polishing. Is preferable. As a result, it is possible to eliminate the possibility that the grinding liquid or the polishing liquid invades the inside of the first or second calcined bodies 1 and 2 and impurities remain in the ceramic sintered body 10. When grinding and polishing are performed, it is preferable that both of these processes are performed by a dry method.

Further, a storage step of storing the first and second SiC calcined bodies 1 and 2 may be provided before the recess forming step STEP5. As a result, by storing the first and second SiC calcined bodies 1 and 2 prepared in advance, the ceramic sintered body 10 can be obtained in a short time at least by the time required for calcining. Further, by storing the first and second SiC calcined bodies 1 and 2 after the first plane forming step STEP3 and the second plane forming step STEP4, the first plane 1a and the second plane are stored. The ceramic sintered body 10 can be obtained in a short time as much as the time required for the step of forming 2a.

In the laminating step STEP6, with reference to FIG. 2B, a state in which the first SiC calcined body 1 and the second SiC calcined body 2 are brought into contact with the first plane 1a and the second plane 2a. Laminate with.

In the laminating step STEP6, it is preferable to interpose a sintering aid containing boron between the first plane 1a and the second plane 2a. As a result, since the sintering aid intervenes in the first and second surfaces 1a and 2a which are the joint surfaces in the firing step STEP7, sintering in the vicinity of the joint surfaces 1a and 2a is promoted, and the bonding strength is improved. It becomes possible to plan. For example, as the sintering aid containing boron, an aqueous boric acid solution or the like can be used.

In the firing step STEP7, the laminated first SiC calcined body 1 and the second SiC calcined body 2 are fired at 2000 ° C. or higher and 2200 ° C. or lower while ^{applying a pressure of 10 kgf / cm 2 or more in the stacking direction.} As a result, referring to FIG. 2C, the ceramic sintered body 10 in which the first and second SiC calcined bodies 1 and 2 are sintered and integrated is obtained.

In the firing step STEP7, pressure sintering is performed by hot pressing or the like that heats at least in a state of being pressurized in the stacking direction. The heating time is preferably 0.1 hour or more and 10 hours or less, and more preferably 1 hour or more and 5 hours or less. The firing atmosphere is, for example, an inert gas atmosphere, but may be an atmosphere such as vacuum.

When the SiC sintered bodies are diffusively bonded to each other and integrated, the SiC sintered body is difficult to process, so that it takes a long time to polish the bonded surface. In the method for producing the ceramic sintered body 10 according to the first embodiment, the first and second flat surfaces 1a and 2a and the recess 3 of the first and second calcined bodies 1 and 2 are ground or polished. It is possible to reduce the time required for polishing. Further, as compared with the case where the SiC molded bodies having the recesses 3 formed are fired and integrated, it is possible to improve the dimensional accuracy of the hollow structure of the ceramic sintered body 10 derived from the recesses 3. ..

Further, as compared with the conventional technique of firing with a small load applied using a weight, firing ^{is performed while applying a pressure of 10 kgf / cm 2} or more, so that the bonding strength is improved and the ceramic sintered body 10 is used. It is possible to improve the precision of the. If the pressure is less than 10 kgf / cm ² , good surface contact between the first and second flat surfaces 1a and 2a of the first and second calcined bodies 1 and 2 cannot be obtained at the time of firing, causing poor joining. Therefore, it is not suitable.

Here, as shown in FIGS. 2B and 2C, a portion between the flow path 4 and the mounting surface F of the ceramic sintered body 10 in the vertical direction of the mounting surface F (vertical direction of FIGS. 2B and 2C). Is defined as the flow path upper region X, and the region between the mounting surface F and the flow path 4 excluding the flow path upper region X is defined as another region Y. In other words, the other region Y can be defined as a region adjacent to the flow path upper region X of the ceramic sintered body in the direction along the mounting surface F.

Generally, when a ceramics sintered body having a flow path through which a cooling medium can flow is used as a base provided with a mounting surface on which a substrate such as a wafer or an electrostatic chuck is mounted, ceramics are used. The distance from the mounting surface of the sintered body to the flow path is straight down depending on the part where the flow path is located directly under the mounting surface and the part where the flow path is not located directly under the mounting surface. The distance differs depending on whether the distance is toward the surface or an oblique inclination, and the distance from the mounting surface to the flow path differs depending on the position of the mounting surface. Therefore, there is a difference in the thermal resistance from the mounting surface of the ceramic sintered body to the flow path.

The fact that the thermal resistance differs depending on the position of the mounting surface of the ceramics sintered body means that when the amount of heat uniformly input to the ceramics sintered body is transferred to the medium flowing through the flow path, the flow path exists directly below. A temperature difference occurs between the mounting surface portion and the portion other than the mounting surface portion.

Therefore, the cooling effect of the medium flowing in the flow path of the ceramic sintered body does not appear uniformly on the mounting surface, which affects the temperature distribution of the substrate mounted on the ceramic sintered body, and the substrate temperature becomes non-uniform. There is a risk of becoming.

However, in the ceramic sintered body 10 of the present embodiment, at least a part of the thermal conductivity of the flow path upper region X (the region surrounded by the dotted line in FIG. 2B) is along the mounting surface F (see FIG. 2B). It is smaller than the thermal conductivity of at least a part of the other region Y (the region surrounded by the alternate long and short dash line in FIG. 2B) adjacent to the flow path upper region X of the ceramic sintered body 10 in the above direction.

This is because the first calcined body 1 and the second calcined body 2 are uniaxially pressure-fired without inserting a core into the recess 3 which is the flow path 4 through which the cooling medium flows, so that the ceramics above the recess 3 are ceramics. The sintered body 10 is not easily affected by the pressure, and the density of the ceramic sintered body 10 becomes sparse, whereas the ceramics are baked on the portion of the mounting surface F where the recess 3 does not exist directly under the pressure. It is considered that the density of the body 10 becomes dense and a difference in thermal conductivity occurs.

As a result, the thermal conductivity of at least a part of the flow path upper region X, which has a short distance between the mounting surface F and the recess 3 as the flow path 4, becomes low, and heat is transferred as compared with the other regions Y. It becomes difficult. On the contrary, the thermal conductivity of at least a part of the other region Y, which has a long distance between the mounting surface F and the flow path 4, becomes large, and heat is more easily transferred than the flow path upper region X. Therefore, it is possible to provide the ceramic sintered body 10 capable of forming a uniform temperature distribution on the mounting surface F.

The thermal conductivity is measured in accordance with JIS R1611 by cutting out a measurement sample having a diameter of 5 mm and a thickness of 1 mm from each of the flow path upper region X and the other region Y.

Further, the temperature difference T (° C.) between the temperature of the mounting surface F and the temperature of the cooling medium can be obtained from the following equation 1.
T = Q / (λ / d) ・ ・ ・ (Equation 1)
However, λ (W / m ² K): thermal conductivity, Q (W / m ² ): heat flux (constant value) incident on the mounted electrostatic chuck, etc., d (m): mounting surface Distance between and the flow path.

Further, the density of the flow path upper region X of the ceramic sintered body 10 becomes sparse, and the density of the other regions Y becomes denser than the flow path upper region X, which means that the bulk density of the flow path upper region X is different. It becomes smaller than the bulk density of the region Y of. As a method for measuring the bulk density, for example, a measurement sample can be cut out from each of the flow path upper region X and the other region Y and measured by the Archimedes method based on JIS-R-1634.

Next, a method for manufacturing the ceramic sintered body 20 according to the second embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 3, the method for producing the ceramic sintered body 20 according to the second embodiment of the present invention includes the first SiC calcined body acquisition step STEP11, the second SiC calcined body acquisition step STEP12, and the second. 3. The SiC calcined body acquisition step STEP13, the first plane forming step STEP14, the second plane forming step STEP15, the recess forming step STEP16, the laminating step STEP17, and the firing step STEP18 are provided.

In the first SiC calcined body acquisition step STEP11 in FIG. 3, referring to FIG. 4A, the first SiC molded body is calcined at a temperature of 1200 ° C. or higher and 1900 ° C. or lower, and the first SiC calcined body is calcined. Get 11. In the second SiC calcined body acquisition step STEP12, the second SiC molded body is calcined at a temperature of 1200 ° C. or higher and 1900 ° C. or lower to obtain a second SiC calcined body 12. The calcining temperatures in the first SiC calcined body acquisition step STEP11 and the second SiC calcined body acquisition step STEP12 may be the same or different.

The first SiC calcined body acquisition step STEP11 is the same as the first SiC calcined body acquisition step STEP1 in FIG. 1 described above, and the second SiC calcined body acquisition step STEP12 is the above-mentioned second SiC calcined body acquisition step STEP12. Since it is the same as the body acquisition step STEP2, the description thereof will be omitted.

In the third SiC calcined body acquisition step STEP13, the third SiC molded body is calcined at a temperature of 1200 ° C. or higher and 1900 ° C. or lower to obtain a third SiC calcined body 13. The third SiC calcined body 13 may be obtained in the same manner as the first or second SiC calcined bodies 11 and 12 described above. The calcining temperature in the third SiC calcined body acquisition step 13 may be the same as or different from the calcining temperature in the first or second SiC calcined body acquisition steps STEP11 and 12. ..

In the laminating step STEP17, the third SiC calcined body 13 includes the first SiC calcined body 11 and the second SiC calcined body 12 with reference to FIG. 4B, and the first plane 11a and the second. When laminated in a state of being in contact with the flat surface 21a of the above, the shape is configured to eliminate steps and recesses on the outside in the lamination direction. For example, when an annular step is formed on the outer peripheral portion of the outer surface of the second calcined body 12 in the stacking direction, the third SiC calcined body 13 is an annular member having a thickness substantially matching the height of the step. Is formed as.

Next, in the first plane forming step STEP14, the first plane 11a is formed on the first SiC calcined body 11. In the second plane forming step STEP15, the second plane 12a is formed on the second SiC calcined body 12.

Since the first plane forming step STEP14 is the same as the first plane forming step STEP3 described above and the second plane forming step STEP15 is the same as the second plane forming step STEP4 described above, the description thereof will be omitted.

Next, in the recess forming step STEP16, the recess 14 is formed on at least one of the first plane 11a and the second plane 12a. Since the recess forming step STEP 16 is the same as the recess forming step STEP 5 described above, the description thereof will be omitted.

Next, in the laminating step STEP17, referring to FIG. 4B, the first SiC calcined body 11 and the second SiC calcined body 12 are brought into contact with each other, and the first plane 11a and the second plane 12a are brought into contact with each other. Laminate in the state of being allowed to.

Further, in the laminating step 17, the third SiC calcined body 13 is laminated on the outside of the first SiC calcined body 11 or the second SiC calcined body 12 in the laminating direction via the release material 15. As a result, the first to third SiC calcined bodies 11 to 13 are laminated in a flat shape by eliminating steps and recesses on the outside in the stacking direction. As the release material 15, for example, a carbon sheet, a boron nitride sheet, or the like can be used. Further, carbon or boron nitride may be directly coated on the first SiC calcined body 11 or the second SiC calcined body 12.

Next, in the firing step STEP18, the laminated first to third SiC calcined bodies 11 to 13 are fired at 2000 ° C. or higher and 2200 ° C. or lower while applying a pressure of 1 MPa or higher in the stacking direction. Since the firing step STEP18 is the same as the firing step STEP7 described above, the description thereof will be omitted.

When the firing step STEP18 is completed, the ceramic sintered body 20 in which the first and second SiC calcined bodies 11 and 12 are sintered and integrated is obtained with reference to FIG. 4C. The ceramic sintered body (not shown) formed by sintering the third SiC calcined body 13 is only in contact with the ceramic sintered body 20 via the release material 15, so that the ceramic sintered body 20 and the ceramic sintered body 20 are used. It can be easily separated from the ceramic sintered body 20 without sintering.

The method for producing the ceramic sintered body 20 according to the second embodiment of the present invention described above also has the same effect as the method for producing the ceramic sintered body 10 according to the first embodiment of the present invention described above. Play.

Further, in the method for manufacturing the ceramic sintered body 20 according to the second embodiment of the present invention, the release material 15 is formed on a step portion or a recess on the outside of the first or second SiC calcined body 11 or 12 in the stacking direction. The third SiC calcined body 13 is pressure-fired in a state of being arranged therethrough. Then, at the time of this firing, the third SiC calcined body 13 shrinks in the same manner as the first and second SiC calcined bodies 11 and 12. As a result, it is possible to make the pressure applied to the first and second SiC calcined bodies 11 and 12 uniform during firing and to improve the bonding strength.

The present invention is not limited to the method for producing the ceramic sintered bodies 10 and 20 specifically described in the first or second embodiment described above, but is within the scope of the claims. If there is, it can be changed as appropriate. For example, the ceramic sintered bodies 10 and 20 are two SiC calcined bodies 1, 2, 11 and 12 integrated, but even if three or more SiC calcined bodies are integrated. Good.

Further, also in the ceramic sintered body 20 of the second embodiment, the thermal conductivity of at least a part of the flow path upper region X is low, and heat is less likely to be transferred as compared with the other regions Y, but the other regions Y The thermal conductivity of at least a part of the above is increased, and heat is more easily transferred than the upper part region X of the flow path. Therefore, it is possible to provide the ceramic sintered body 10 capable of forming a uniform temperature distribution on the mounting surface F. The thermal conductivity is the same as in the first embodiment, in which a measurement sample having a diameter of 5 mm and a thickness of 1 mm is cut out from each of the flow path upper region X and the other region Y and measured in accordance with JIS R1611. is there.

Further, also in the second embodiment, the density of the flow path upper region X of the ceramic sintered body 10 becomes dense, and the density of the other regions Y becomes sparser than the flow path upper region X, which means that the flow path upper region The bulk density of X is smaller than the bulk density of the other region Y. As a method for measuring the bulk density, for example, a measurement sample can be cut out from each of the flow path upper region X and the other region Y and measured by the Archimedes method based on JIS-R-1634.

(Examples 1 to 7)
In Examples 1-7, the first and second SiC calcined body obtaining step STEP1,2, first, 98% purity, the SiC powder having an average particle diameter of 0.5 [mu] m, _B 4 C as a sintering aid , C (carbon), and a binder such as PVA added as a molding aid was used as a raw material and granulated to obtain granules.

Then, the granules were filled in a mold and uniaxially pressure-molded at a pressure of 20 MPa to obtain two SiC molded bodies. The bulk densities of these SiC molded products were as shown in Table 1. Next, these SiC compacts were fired in an argon atmosphere in an argon atmosphere at a temperature of 1200 ° C. to 1900 ° C. for 3 hours to obtain two SiC calcined bodies. The bulk density after calcining and the shrinkage rate due to calcining were as shown in Table 1.

Next, as the first and second plane forming steps STEP3 and 4, two SiC calcined bodies were subjected to the first and second square plate-shaped first and second plates having a side of 100 mm and a height of 10 mm with reference to FIG. 2A. It was processed into SiC calcined bodies 1 and 2. The first flat surface 1a of the first SiC calcined body 1 and the second flat surface 2a of the second SiC calcined body 2 have diamond abrasive grains of # 170 in Examples 1 to 4, 6 and 7. Grinding was performed using the provided grindstone. Then, in Example 5, grinding was performed using a grindstone equipped with # 600 diamond abrasive grains. The grinding process was performed by a dry method without using a polishing liquid. The average arithmetic mean roughness (Ra) and maximum height (Rz) of the first and second planes 1a and 2a are as shown in Table 1.

Next, as the recess forming step STEP5, the recess 3 was formed on the second flat surface 2a of the second SiC calcined body 2. The recesses 3 were three linear grooves having a width of 20 mm, a depth of 5 mm, and a length of 70 mm. The recess 3 was formed by MC processing using an end mill having a diameter of 20 mm. The evaluation of the workability of this MC processing is as shown in Table 1.

The evaluation was made based on the load on the spindle during processing, chattering, and damage to the calcined body. In Table 1, the evaluation “⊚” means that the depth of cut in one pass can be 0.25 mm or more and the blade feed amount can be 250 mm / min or more, which is excellent. Evaluation "○" means that the depth of cut in one pass can be 0.2 mm or more and the blade feed amount can be 200 mm / min or more. The evaluation "Δ" means that the depth of cut in one pass can be 0.15 mm or more and the blade feed amount can be 150 mm / min or more.

From this, regarding the workability when forming the concave portion 3, the concave portion 3 can be formed if the calcining temperature is 1200 ° C. or higher and 1900 ° C., but it is good if it is 1250 ° C. or higher and 1785 ° C. or lower. I understood.

Next, as the laminating step STEP6, referring to FIG. 2B, the first SiC calcined body 1 and the second SiC calcined body 2 are brought into contact with the first plane 1a and the second plane 2a. It was laminated in a state of being.

Next, as the firing step STEP7, the first and second SiC calcined bodies 1 and 2 thus laminated are sandwiched between carbon flat plates as pressing plates in an argon atmosphere in the firing furnace, and Examples 1 to 6 are performed. in load of ^{25kgf / cm 2 (= 2.45MPa)} , while applying a load of example 7, 10kgf ^/ cm 2 (= 0.98MPa) in the stacking direction, and calcined 3 hours furnace temperature as 2070 ° C.. As a result, the ceramic sintered body 10 was obtained with reference to FIG. 2C. The thermal conductivity and bulk density of the upper flow path region X and the other regions Y of the ceramic sintered body 10 are as shown in Table 1. As a result, in all of Examples 1 to 7, the thermal conductivity of the other region Y is 11 W / mK to 18 W / mK larger than the thermal conductivity of the flow path upper region X, and the bulk density of the flow path upper region X is different. It was confirmed that the bulk density of the region Y was 0.02 g / cm ^{3 to} 0.05 g / cm ^{3 smaller than that of the region Y.}

Then, the ceramic sintered body 10 was cut so as to include the joint portion, the cut surface was polished, and then the joint portion was visually inspected using a magnifying glass or the like. As a result, no joint failure or breakage was confirmed in the joint portion, and no breakage or distortion was confirmed in the hollow structure derived from the recess 3.

The results of Examples 1 to 7 are summarized in Table 1.

(Example 8)
In Example 8, as the first and second plane forming steps STEP3 and 4 in FIG. 1, two SiC calcined bodies are formed into a disk shape having a diameter of 400 mm and a thickness of 10 mm with reference to FIG. 5A. It was processed into a first SiC calcined body 21 and a disc-shaped second SiC calcined body 22 having a diameter of 400 mm and a thickness of 25 mm. The first flat surface 21a of the first SiC calcined body 21 and the second flat surface 22a of the second SiC calcined body 22 were ground using a grindstone equipped with diamond abrasive grains of # 170. At this time, the grinding process was performed by a dry method without using a polishing liquid. The average arithmetic mean roughness (Ra) and maximum height (Rz) of the first and second planes 21a and 22a are as shown in Table 2. Further, as the recess forming step STEP5 in FIG. 1, the recesses 23 and 24 were formed by the same MC processing as in Example 1. The recess 23 is formed on the second flat surface 22a of the second SiC calcined body 22 in a circumferential shape having a width of 20 mm and a depth of 5 mm. The recess 24 is formed in an annular shape having a width of 25 mm and a depth of 15 mm on the outer peripheral portion of the surface of the second SiC calcined body 22 opposite to the second flat surface 22a. A ceramic sintered body 30 was produced in the same manner as in Example 1 except for these matters.

In this ceramic sintered body 30, as in Example 1, no joint failure or breakage was confirmed in the joint portion, and no breakage or distortion was confirmed in the hollow structure derived from the recess 23. The results of Example 8 are summarized in Table 2. Then, in the ceramic sintered body 30 produced in Example 8, the thermal conductivity of the other region Y is larger than the thermal conductivity of the flow path upper region X, and the bulk density of the flow path upper region X is the other region Y. It was confirmed that it was smaller than the bulk density of.

A heat amount of 3000 W was applied to the mounting surface F of the ceramic sintered body 30 produced in Example 8, and the temperature of the mounting surface F was measured in a state where a refrigerant at 20 ° C. was circulated in the flow path 4. An infrared thermometer was used for temperature measurement. The temperature of the upper flow path region X was 23.8 ° C, and the temperature of the other region Y was 23.7 ° C. It was confirmed that the temperature difference between the upper part region X of the flow path and the other region Y was small, and a more uniform temperature distribution on the mounting surface F could be achieved.

(Example 9)
In Example 9, first and second SiC calcined bodies 21 and 22 were obtained in the same manner as in Example 8 except for the grinding method for the first and second flat surfaces 21a and 22a.

More specifically, the first and second SiC calcined bodies 21 and 22 are ground by using a grindstone equipped with diamond abrasive grains of # 600, and the first and second flat surfaces 21a and 22a are subjected to grinding. The average arithmetic mean roughness (Ra) was set to 0.27 μm. Further, using another SiC sintered body having a plane having an arithmetic mean roughness (Ra) of 0.01 μm, it is slid at a speed of 0.5 m / min while applying a load of 6000 Pa perpendicular to the plane direction to dry type. Polished with. As a result, the average arithmetic mean roughness (Ra) of the first and second planes 21a and 21b became 0.18 μm.

Next, in the same manner as in Example 8, the laminating step STEP6 and the firing step STEP7 in FIG. 1 were performed. As a result, the ceramic sintered body 30 was obtained.

Similarly to Example 8, in this ceramic sintered body 30, no joint failure or breakage was confirmed in the joint portion, and no breakage or distortion was confirmed in the hollow structure derived from the recess 23. The results of Example 9 are summarized in Table 3. Then, in the ceramic sintered body 30 produced in Example 9, the thermal conductivity of the other region Y is larger than the thermal conductivity of the flow path upper region X, and the bulk density of the flow path upper region X is the other region Y. It was confirmed that it was smaller than the bulk density of.

(Example 10)
In Example 10, the first and second SiC calcined body acquisition steps STEP11 and 12 in FIG. 3 were carried out in the same manner as in the first and second SiC calcined body acquisition steps STEP1 and 2 of Example 8. Two SiC compacts were obtained. Next, these SiC compacts were fired in an argon atmosphere in an argon atmosphere at a temperature of 1500 ° C. for 3 hours to obtain two SiC calcined bodies.

Further, as the third SiC calcined body acquisition step STEP13, a SiC molded body was obtained in the same manner as in the first and second SiC calcined body acquisition steps STEP1 and 2 of Example 1. Next, this SiC molded product was fired in an argon atmosphere in an argon atmosphere at a temperature of 1500 ° C. for 3 hours to obtain one SiC calcined product.

Next, as the first and second plane forming steps STEP14 and 15 in FIG. 3, referring to FIG. 4A, the two SiC calcined bodies are first formed into a disk shape having a diameter of 400 mm and a thickness of 10 mm. The SiC calcined body 11 and the second SiC calcined body 12 having a diameter of 400 mm and a thickness of 25 mm were processed. The first flat surface 11a of the first SiC calcined body 11 and the second flat surface 12a of the second SiC calcined body 12 were ground using a grindstone equipped with diamond abrasive grains of # 170. Further, the one SiC calcined body was processed into a ring-shaped third SiC calcined body 13 having an outer diameter of 400 mm, an inner diameter of 350.5 mm, and a thickness of 14.5 mm.

Next, as the recess forming step STEP16, the recess 14 is formed on the second flat surface 12a of the second SiC calcined body 12, and the surface of the second SiC calcined body 12 on the side opposite to the second flat surface 12a. An annular recess having a width of 25 mm and a depth of 15 mm was formed on the outer peripheral portion of the above. The recess 14 had a width of 10 mm and a depth of 10 mm, and had a circumferential shape corresponding to a flow path for a refrigerant. The recess 14 was formed by MC processing in the same manner as in Example 8.

Next, as the laminating step STEP17, referring to FIG. 4B, the first SiC calcined body 11 and the second SiC calcined body 12 are brought into contact with each other, and the first plane 11a and the second plane 12a are brought into contact with each other. It was laminated in a state of being. Further, the third SiC calcined body 13 is placed on the outer periphery of the outer peripheral side of the second SiC calcined body 12 via the release material 15, and the first flat surface 11a of the first SiC calcined body 11 is passed through the release material 15. It was installed below. As the release material 15, a carbon sheet having a thickness of 0.25 mm was used.

Next, as the firing step STEP18, the first to third SiC calcined bodies 11 to 13 thus laminated were fired in the same manner as in the firing step STEP7 of Example 1. Then, by peeling off the portion where the third SiC calcined body 13 was fired, the ceramic sintered body 20 was obtained with reference to FIG. 4C.

Then, the ceramic sintered body 20 was cut so as to include the joint portion, the cut surface was polished, and then the joint portion was visually inspected using a magnifying glass or the like. As a result, no joint failure or breakage was confirmed in the joint portion, and no breakage or distortion was confirmed in the hollow structure derived from the recess 14. Further, in the ceramic sintered body 20 produced in Example 10, the thermal conductivity of the other region Y is larger than the thermal conductivity of the flow path upper region X, and the bulk density of the flow path upper region X is the other region Y. It was confirmed that it was smaller than the bulk density of.

(Example 11)
In Example 11, in the laminating step STEP6 in FIG. 1, the concentration of 0.3 g / g / on the first surface 21a of the first SiC calcined body 21 and the second surface 22a of the second SiC calcined body 22. A ceramic sintered body 30 was produced in the same manner as in Example 8 except that the first and second SiC sintered bodies 21 and 22 were laminated after applying L for an aqueous boric acid solution.

Similar to Example 8, in this ceramic sintered body 30, no joint failure or breakage was confirmed in the joint portion, no breakage or distortion was confirmed in the hollow structure derived from the recess 23, and the other region Y was not confirmed. It was confirmed that the thermal conductivity of the flow path upper region X is larger than that of the flow path upper region X, and the bulk density of the flow path upper region X is smaller than the bulk density of the other regions Y.

The results of Examples 8 to 11 are summarized in Table 2.

(Comparative Example 1)
In Comparative Example 1, first, instead of the first and second calcined body acquisition steps STEP1 and 2 and the recess forming step STEP6 in Example 1, two SiC molded bodies having recesses formed in advance were placed in the firing furnace. The first SiC sintered body and the second SiC sintered body were prepared by firing in an argon atmosphere at a furnace temperature of 2070 ° C. for 3 hours. The first SiC sintered body having the first flat surface has a disk shape having a diameter of 400 mm and a thickness of 10 mm, and the second SiC sintered body having the second flat surface has a diameter of 400 mm and a thickness of 25 mm. The second plane has a disk-shaped recess having a width of 20 mm and a depth of 5 mm, and the outer peripheral portion of the surface opposite to the second plane has an annular recess having a width of 25 mm and a depth of 15 mm. ..

Next, as the first and second plane forming steps STEP3, # 170 and # with respect to the first plane of the first SiC sintered body and the second plane of the second SiC sintered body, # 170 and # After grinding with a grindstone equipped with 600 diamond abrasive grains, wrapping with 1 μm diamond free abrasive grains was performed. In the first and second planes, the average arithmetic mean roughness (Ra) was 0.1 μm, and the average maximum height (Rz) was 1.1 μm. A ceramic sintered body 30 was produced in the same manner as in Example 1 except for these matters.

In the ceramic sintered body 30 of Comparative Example 1, the thermal conductivitys of the flow path upper region X and the other region Y are both 158 W / mK, and the bulk densities of the flow path upper region X and the other region Y are both 3. It was .12 g / cm ³ , and no difference in thermal conductivity or bulk density was observed between the upper channel area X and the other area Y.

The temperature of the upper flow path region X of the ceramic sintered body of Comparative Example 1 measured in the same manner as in Example 8 was 23.0 ° C., and the temperature of the other region Y was 23.7 ° C. It can be seen that the temperature distribution on the mounting surface is non-uniform as compared with Example 8.

1,11,21 First SiC calcined body 1a, 11a, 21a First flat surface 2,12,22 Second SiC calcined body 2a, 12a, 22a Second flat surface 3, 14, 23 Recess 13 3 SiC calcined body 15 release material 10, 20, 30 Ceramic sintered body F mounting surface X flow path upper region Y other region

Claims (3)

A ceramics sintered body having a mounting surface on which a substrate is mounted.
The ceramics sintered body extends along the previously described surface at a position away from the previously described surface and includes a flow path through which the medium flows.
The portion of the ceramic sintered body in the vertical direction between the above-mentioned mounting surface and the above-mentioned mounting surface is defined as a flow path upper region.
The thermal conductivity of at least a part of the flow path upper region is higher than the thermal conductivity of at least a part of the other region adjacent to the flow path upper region of the ceramic sintered body in the direction along the above-mentioned mounting surface. Ceramic sintered body characterized by being small in size. The ceramic sintered body according to claim 1.
A ceramic sintered body characterized in that the bulk density of at least a part of the flow path upper region is smaller than the bulk density of at least a part of the other region. The ceramic sintered body according to claim 1 or 2.
The ceramics sintered body is a ceramics sintered body characterized by containing silicon carbide as a main component.

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