JP2015160777A - Member for heat insulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member for heat insulation having an improved heat insulation property.SOLUTION: A member 20 for heat insulation comprises ceramics, includes a lid body part 1, a bottom plate part 2, a side wall part 3, and a partition part 5 provided inside the side wall part, and has a closed space 4 enclosed by each part. Further, At least each portion of the lid body part 1, the bottom plate part 2, the side wall part 3 and the partition part 5 is a porous body, respectively.

Description

  The present invention relates to a heat insulating member.

  2. Description of the Related Art Thermal insulation members are widely known as members used for suppressing heat from being transmitted to the outside. In recent years, from the viewpoint of energy saving, a heat insulating member having more excellent heat insulating performance has been demanded. For example, in the semiconductor manufacturing field, there are processes with large temperature changes, and excellent heat insulating members are required for improving efficiency.

  As such a heat insulating member, for example, in Patent Document 1, two plate-like bodies are held at a predetermined interval, and the peripheral end portions of the two plate-like bodies are sealed with a sealing material. In the multilayer body in which the low-pressure space is formed, the rare gas constituting the low-pressure space includes a single gas in H, He, Ne or a mixed gas of two or more kinds. A multilayer body having a low-pressure space characterized by the following has been proposed.

Japanese Patent Laid-Open No. 11-1557884

  However, at present, there is a demand for a heat insulating member having further improved heat insulating performance from the viewpoint of energy saving.

  The present invention has been devised to satisfy the above requirements, and provides a heat insulating member with improved heat insulating performance.

  The heat insulating member of the present invention is made of ceramics, includes a lid part, a bottom plate part, and a side wall part, and has a closed space surrounded by each, and the lid part, the bottom plate part, At least a part of the side wall portion is a porous body.

  According to the heat insulation member of the present invention, a heat insulation member with improved heat insulation performance can be obtained.

An example of the member for heat insulation of this embodiment is shown, (a) is a perspective view, (b) is sectional drawing in the AA in (a). The other example of the member for heat insulation of this embodiment is shown, (a) is a perspective view, (b) is sectional drawing in the BB line in (a). The other example of the member for heat insulation of this embodiment is shown, (a) is a perspective view, (b) is sectional drawing in the CC line in (a). The other example of the member for heat insulation of this embodiment is shown, (a) is a perspective view, (b) is sectional drawing in the DD line in (a). The other example of the member for heat insulation of this embodiment is shown, (a) is a perspective view, (b) is sectional drawing in the EE line in (a). The other example of the member for heat insulation of this embodiment is shown, (a) is a perspective view, (b) is sectional drawing in the FF line in (a).

  1A and 1B show an example of a heat insulating member of the present embodiment. FIG. 1A is a perspective view, and FIG. 1B is a cross-sectional view taken along line AA in FIG. In the following drawings, the same members are assigned the same numbers.

  As shown in FIG. 1 (a), the heat insulating member 10 of the present embodiment is made of ceramics, and has a lid portion 1, a bottom plate portion 2, and a side wall portion 3, and is a closed space surrounded by each. 4.

  The heat insulating member 10 of the present embodiment functions as the heat insulating member 10 when the heat insulating object is located on the lid body portion 1 side or the bottom plate portion 2 side. In addition, these heat insulation objects do not ask | require conditions, such as gas, liquid, and solid. And by using the member 10 for heat insulation of this embodiment, the heat insulation target object can be kept at a constant temperature, and heat radiation from the heat insulation target object can be suppressed.

  In addition, since the heat insulating member 10 of the present embodiment is made of ceramics, there is little risk of contamination even when used in a corrosive gas or plasma environment.

  And as for the heat insulation member 10 of this embodiment, at least one part of the cover body part 1, the baseplate part 2, and the side wall part 3 is a porous body. In addition, in FIG.1 (b), the example whose at least one part of the side wall part 3 is a porous body is shown.

  Since at least a part of the lid 1, the bottom plate 2, and the side wall 3 is a porous body, in other words, the number of pores (voids) having poor heat conduction increases, Or since heat becomes difficult to conduct to the heat insulation object located in the other side, or heat of heat insulation object becomes difficult to radiate, heat insulation performance can be improved.

  Here, the porous body may be provided in consideration of mechanical strength as the heat insulating member 10. Therefore, FIG. 1B shows an example in which at least a part 3a of the side wall part 3 is made of a porous body. However, the entire side wall part 3 is made of a porous body, and at least one of the lid part 1 is made. A part can be made into a porous body, and at least one part of the baseplate part 2 can also be made into a porous body.

  However, when at least a part of the lid portion 1, the bottom plate portion 2, and the side wall portion 3 is a porous body, the lid portion 1, the bottom plate portion 2, The space surrounded by the side wall 3 is preferably a closed space 4, and in this case, it is preferable that this space does not communicate with the outside. Therefore, for example, in FIG. 1B, when at least a part of the side wall portion 3 is made a porous body, a dense body 3b is provided in a region in contact with the outside of the side wall portion 3. By doing in this way, since the space enclosed by the cover body part 1, the baseplate part 2, and the side wall part 3 turns into the closed space 4, heat insulation performance can be improved. The dense body 3b may be provided on the inner side of the side wall part 3 (part in contact with the closed space 4).

  Moreover, in this embodiment, a porous body means a thing whose porosity is 25 volume% or more and 80 volume% or less. If the porosity of the porous body is within this range, the heat insulation performance can be improved while maintaining the mechanical strength.

  Further, as a method for confirming the porous body, it can be determined by cutting a sample containing the porous body from the heat insulating member 10 and measuring the porosity by using the Archimedes method.

  Here, as the material of the heat insulating member 10, it is possible to use ceramics that are alumina, zirconia, silicon nitride, aluminum nitride, silicon carbide, boron carbide, cordierite, mullite, steatite, forsterite, or a composite thereof. it can.

  In particular, the heat insulating member of the present embodiment is preferably made of a silicon carbide based sintered body containing silicon carbide as a main component. Here, a main component means the component which occupies in the ratio of 80 mass% or more among the components which comprise the member for heat insulation. And when the member for heat insulation of this embodiment consists of a silicon carbide sintered body which has silicon carbide as a main component, since mechanical characteristics and corrosion resistance are high, reliability improves. In addition, since the specific gravity is smaller than that of other ceramics such as alumina, the weight can be reduced when a large heat insulating member 10 is required.

  Note that the closed space 4 preferably has a lower thermal conductivity than the lid 1, the bottom plate 2, and the partition 3. In particular, the low-pressure space is suitable, for example, 20 kPa or less is suitable.

  2A and 2B show another example of the heat insulating member of the present embodiment. FIG. 2A is a perspective view, and FIG. 2B is a cross-sectional view taken along line BB in FIG.

  As shown in FIGS. 2A and 2B, the heat insulating member 20 of the present embodiment is made of ceramics, and includes a lid portion 1, a bottom plate portion 2, a side wall portion 3, and a partition wall portion 5. And a closed space 4 surrounded by each.

  And as shown in FIG.2 (b), at least one part of the cover part 1, the baseplate part 2, the side wall part 3, and the partition part 5 is porous in the heat insulation member 20 of this embodiment. In other words, because the number of pores (voids) having poor heat conduction increases, it becomes difficult for heat to be conducted to the heat insulation object located on one or the other side of the heat insulation member 10, or the heat insulation object Since it becomes difficult for heat to be dissipated, the heat insulation performance can be improved.

  Furthermore, since the mechanical strength of the heat insulating member 20 itself can be increased by providing the partition wall portion 5, the heat insulating member 20 with improved reliability can be obtained.

  Here, for example, FIG. 2B shows an example in which the partition wall 5 is a porous body. However, for example, at least a part of the lid 1, at least a part of the bottom plate 2, and a side wall At least a part of the portion 3 can be made porous.

  The partition wall portion 5 is preferably arranged so that the mechanical strength of the heat insulating member 20 is maintained. For example, the partition wall portion 5 has a shape in which a space is provided in part, and the paper surface of FIG. It is good also as a shape separated and provided in multiple directions in the direction perpendicular | vertical.

  3A and 3B show still another example of the heat insulating member of the present embodiment, in which FIG. 3A is a perspective view, and FIG. 3B is a cross-sectional view taken along line CC in FIG.

  The heat insulating member 30 of the example shown in FIG. 3 is obtained by providing the partition wall portion 5 on the heat insulating member 10 shown in the present embodiment shown in FIG. Here, the heat insulating member 30 shown in FIG. 3 is characterized in that the porosity of the partition wall portion 5 is higher than the porosity of the side wall portion 3. In the heat insulating member 30 shown in FIG. 3, the porosity of the partition wall portion 5 is higher than the porosity of the porous body 3a and the dense body 3b of the side wall portion 3. As described above, since the porosity of the partition wall portion 5 is higher than the porosity of the side wall portion 3, the temperature of the heat insulation object located on either the lid body portion 1 side or the bottom plate portion 2 side is particularly high. Since the heat insulation effect near the center which is easy to concentrate can be enhanced, the heat insulation performance can be further improved.

  4A and 4B show still another example of the heat insulating member of the present embodiment, in which FIG. 4A is a perspective view, and FIG. 4B is a cross-sectional view taken along line DD in FIG.

In the example of the heat insulating member 40 shown in FIG. 4, when the heat insulating object is located on the lid body 1 side,
2 is different from the heat insulating member 20 in the example shown in FIG. 2 in that at least one of the partition wall portion 5 and the side wall portion 3 is a porous body whose porosity increases toward the lid body portion 1. Yes. Specifically, in FIG. 4, the porosity of the partition wall portion 5 is such that the partition wall portion 5 a <the partition wall portion 5 b <the partition wall portion 5 c from the bottom plate portion 2 side. In addition, when a heat insulation target object is located in the baseplate part 2 side, the porosity should just become high toward the baseplate part 2. As shown in FIG.

  Thus, the mechanical insulation of the partition part 5 and the side wall part 3 is made high, improving the heat insulation performance because the heat insulation target object has a high porosity of at least one of the partition part 5 and the side wall part 3. Therefore, the heat insulating member 40 with improved heat insulating performance and reliability can be obtained.

  Here, as a method for confirming the change in the porosity of the side wall 3 or the partition wall 5, for example, a sample including the side wall 3 or the partition 5 is cut out from the heat insulating member 40, and the sample is removed from the lid 1 side. The size of the porosity can be compared by cutting evenly toward the part 2 side (for example, three divisions) and measuring the porosity for each sample using the Archimedes method. .

  5A and 5B show still another example of the heat insulating member of the present embodiment. FIG. 5A is a perspective view, and FIG. 5B is a cross-sectional view taken along line EE in FIG.

  The heat insulating member 50 of the example shown in FIG. 5 is a point that at least one of the partition wall portion 5 and the side wall portion 3 is a porous body whose porosity increases toward the central portion in the height direction. This is different from the heat insulating member 50 in the example shown in FIG.

  For example, in an environment where the object to be insulated is a gas or liquid and the pressure and temperature thereof change, the partition wall 5 and the side wall 3 have high strength on the lid 1 side or bottom plate 2 side. It is preferable to do. However, in this case, in order to increase the strength, it is necessary to lower the porosity, and on the other hand, the heat insulation performance may be reduced.

  Therefore, in the heat insulating member 50 of the present embodiment, the strength can be maintained high by increasing the porosity of at least one of the partition wall portion 5 and the side wall portion 3 toward the central portion in the height direction. it can. Furthermore, since the heat | fever of the heat insulation target object can be suppressed because the porosity of the center part of a height direction is high, heat insulation performance can also be made high.

  In addition, the above-mentioned method can be used for the confirmation method of the porosity change of the side wall part 3 or the partition part 5.

  6A and 6B show still another example of the heat insulating member of the present embodiment, in which FIG. 6A is a perspective view, and FIG. 6B is a cross-sectional view taken along line FF in FIG.

The heat insulating member 60 in the example shown in FIG. 6 is an example shown in FIG. 2 in that at least one of the partition wall portion 5 and the side wall portion 3 is narrowed toward the lid body portion 1 or the bottom plate portion 2. This is different from the heat insulation member 20. As described above, when at least one of the partition wall portion 5 and the side wall portion 3 is narrower toward the lid body portion 1 or the bottom plate portion 2, the heat insulation performance can be improved. For example, when the heat insulation target object is located on the lid body 1 side, as shown in FIG. 6B, the partition wall 5 is narrowed toward the lid body 1, thereby reducing the closed space 4. In addition to being able to increase the volume of the lid part 1 side, heat transmitted from the bottom plate part 2 on the side opposite to the side on which the object to be insulated is located can be suppressed, so that the heat insulation performance can be enhanced.

  In FIG. 6B, a part of the partition wall 5 is stepped, but it may be straight so as to be continuously narrowed.

  In addition, the heat insulating members 10, 20, 30, 40, 50, 60 of the present embodiment have a coefficient of thermal expansion higher than that of the ceramic constituting the lid portion 1, the bottom plate portion 2, and the side wall portion 3, depending on the intended use. A large metal spraying process mainly composed of stainless steel, aluminum, titanium or other alloys may be performed. The compressive stress is generated due to the thermal contraction of the metal during the metal spraying process, whereby the strength of the lid body part 1, the bottom plate part 2 and the side wall part 3 can be improved. In addition, it is preferable to perform a metal spraying process so that the whole outer surface of the cover body part 1, the baseplate part 2, and the side wall part 3 may be covered.

  As described above, the heat insulating member 10, 20, 30, 40, 50, 60 of the present embodiment can be used as a heat insulating member with improved heat insulating performance, and therefore used in a field that requires heat insulation. However, it is particularly suitable for use as a member for a semiconductor manufacturing apparatus used in the semiconductor manufacturing field where a process with a large temperature change exists.

  Next, an example of a method for producing the heat insulating members 10, 20, 30, 40, 50, 60 of the present embodiment will be described.

First, a ceramic raw material having a purity of 90% or more and an average particle diameter of 0.5 μm or more and 2 μm or less is prepared, and a predetermined amount of a sintering aid, a binder, a solvent, a dispersing agent and the like are added thereto to obtain a mixed slurry. .

  For a molded body of a member that is not a porous body, the slurry is molded by a doctor blade method, or spray-dried by spray granulation (spray dry method) and granulated, and used as a primary material. It can be obtained by molding by an isostatic pressing method, a powder pressing method, a roll compaction method or the like.

  And about the molded object of the member used as a porous body, the particulate or bead-like organic substance (for example, starch, resin beads, etc.) which lose | disappears simultaneously with the degreasing process or baking process with respect to ceramic powder with respect to a slurry or a primary raw material. It can be produced by adding and applying the molding method described above. Or it can produce also by adjusting the green density at the time of shaping | molding.

  Moreover, after producing a molded object, a desired shape can be obtained by performing a drill process and a laser process as needed.

  After obtaining the molded body to be the lid 1, the bottom plate 2, the side wall 3, and the partition wall 4, these are joined using a bonding agent, thereby heat insulating members 10, 20, 30, 40, 50, 60. A molded body is obtained. As a bonding agent used for bonding, predetermined amounts of ceramic raw materials, sintering aids, binders, dispersants, and solvents used in the production of the molded body that will be the lid body part 1, the bottom plate part 2, the side wall part 3, and the partition wall part 4 are used. A bonding agent made of a slurry prepared by weighing and mixing is used.

In addition, as an example of another method for producing a molded body, a green sheet is formed by a roll compaction molding method after granulating a doctor blade method or a slurry, which is a general ceramic molding method using slurry, and laser processing or You may form a molded object by laminating | stacking the green sheet processed into the desired shape with the metal mold | die. Especially in the case of roll compaction molding,
By adjusting the green density by changing the molding pressure, a molded body of a member that becomes a porous body can be produced. In addition, after lamination | stacking, you may process to a desired shape by drilling or laser processing.

As an example of a method for preparing a slurry for obtaining a green sheet, in obtaining the heat insulating members 10, 20, 30, 40, 50, 60 made of a silicon carbide sintered body, first, the average particle size is 0.5. A silicon carbide powder having a size of not less than μm and not more than 2 μm and boron carbide and carboxylate powder as a sintering aid are prepared. The sintering aid is, for example, 0.12 to 1.4% by mass of boron carbide powder and 1 to 3.4% by mass of carboxylate powder with respect to 100% by mass of silicon carbide powder. Weigh and mix as above.

  Next, together with this mixed powder, a binder such as polyvinyl alcohol, polyethylene glycol, acrylic resin or butyral resin, water, and a dispersing agent are mixed in a ball mill, a rotating mill, a vibration mill or a bead mill. Here, the added amount of the binder may be such that the strength and flexibility of the molded body are good and that the debinding of the molding binder is not insufficient during firing. What is necessary is just to produce a green sheet using the slurry produced in this way. In addition, when it is desired to obtain a molded body of a member desired to be made into a porous body, particulate or bead-like organic substances (for example, starch, resin beads, etc.) that disappear simultaneously with the degreasing process or firing process for the ceramic powder with respect to the slurry or the primary raw material ) Can be added. The porosity can be controlled by the addition amount at this time.

  Next, the plurality of green sheets thus produced are laminated so as to form a desired closed space 4 by changing the thickness or changing the number of green sheets to be laminated.

  Here, with respect to the porous body in contact with the outside, the slurry is applied to the molded body of the member that becomes the porous body, so that the region in contact with the outside in the side wall portion 3 is densely formed as shown in FIG. The body 3b can be formed.

  As another method for forming the dense body 3b, a molded body of a member that is not a porous body is manufactured by lamination, and separately, a molded body of a member that becomes a porous body is manufactured by lamination, and the interface between the two is in contact. It can also be produced by applying and adhering slurry. In addition, when it has the area | region which contacts the exterior in the cover part 1 or the baseplate part 2, it can produce similarly.

  In addition, a slurry similar to that used for producing the green sheet is applied as a bonding agent to the bonding surface of each green sheet, and after the green sheets are laminated, a flat plate-like pressurizing tool is used. A pressure of about 0.5 MPa is applied, followed by drying at room temperature of about 50 to 70 ° C. for about 10 to 15 hours.

  Since the molded body produced in this way is integrally molded without using an adhesive made of glass or organic matter, the possibility of contamination even when used in any environment can be reduced.

Next, the molded body to be the heat insulating members 10, 20, 30, 40, 50, 60 is fired in, for example, a known pusher type or roller type continuous tunnel furnace. Although the firing temperature differs depending on the material, for example, if silicon carbide is the main material, in an inert gas atmosphere or in a vacuum atmosphere, 10 minutes in the range of 400 ° C. to 800 ° C. for degreasing After holding for 72 hours, holding at a temperature range of 1800 to 2200 ° C. for 10 minutes to 10 hours, holding at a temperature range of 2200 to 2350 ° C. for 10 minutes to 20 hours may be performed. In particular, when a particulate or bead-like organic substance that disappears simultaneously with the degreasing step or the firing step for the ceramic powder is added to the slurry or the primary raw material, the porous body 3a can be obtained by passing through this step. .

  Here, in making the closed space 4 into a low-pressure space, the firing atmosphere may be an inert gas atmosphere, and after the firing, cooling may be performed for one hour or more. The pressure of the inert gas existing in the region that becomes the closed space 4 at the time of firing becomes a low pressure as it cools, and as a result, the closed space 4 can be a low pressure space. Note that as the inert gas, a rare gas such as argon or helium, carbon monoxide, carbon dioxide, nitrogen, or the like can be used.

1: Cover body part 2: Bottom plate part 3: Side wall part 4: Closed space 5: Partition part
10, 20, 30, 40, 50, 60: Insulating material

Claims (7)

  It is made of ceramics, and includes a lid part, a bottom plate part, and a side wall part, and has a closed space surrounded by each, and at least a part of the lid part, the bottom plate part, and the side wall part is A heat insulating member characterized by being a porous body.   Made of ceramics, comprising a lid part, a bottom plate part, a side wall part, and a partition part provided inside the side wall part, and having a closed space surrounded by each, the lid part, At least a part of the bottom plate part, the side wall part, and the partition wall part is a porous member.   The heat insulating member according to claim 2, wherein a porosity of the partition wall is higher than a porosity of the side wall.   4. The porous body according to claim 1, wherein at least one of the partition wall and the side wall is a porous body having a higher porosity toward the lid body or the bottom plate. The member for heat insulation as described in any one of them.   4. The method according to claim 1, wherein at least one of the partition wall and the side wall is a porous body having a porosity that increases toward a central portion in a height direction. The member for heat insulation as described in a crab.   The heat insulation according to any one of claims 1 to 5, wherein at least one of the partition wall and the side wall is narrowed toward the lid or the bottom plate. Materials.   The heat insulating member according to any one of claims 1 to 6, wherein at least a part of the outer surface of the lid, the bottom plate, and the partition is covered with a metal or an alloy. .

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