Ceramic structure

Abstract

A ceramic structure according to one aspect of the present disclosure comprises: a base body that is made of ceramic and has a first surface, a second surface positioned opposite from the first surface, and a side surface connecting the first surface and the second surface; an internal space that is open in the first surface and extends from the first surface toward the second surface inside the base body; and a heat insulation space positioned between the internal space and the side surface. The heat insulation space is closed on the second surface side.

Description

Ceramic structure

[0001] The present disclosure relates to a ceramic structure.

[0002] Patent Document 1 discloses a structure in which an aerogel, which is an example of a heat insulating material, is located between a flexible film heater and an outer tube that houses the film heater.

[0003] Japanese Patent No. 7406670

[0004] A ceramic structure according to one aspect of the present disclosure is made of ceramics and has a substrate having a first surface, a second surface located opposite to the first surface, and a side surface connecting the first surface and the second surface. A ceramic structure according to one aspect of the present disclosure has an internal space that opens on the first surface and extends from the first surface toward the second surface inside the substrate, and a heat insulating space located between the internal space and the side surface. The heat insulating space is a space closed on the second surface side.

[0005] FIG. 1 is a perspective view of a substrate in a ceramic structure according to the first embodiment. FIG. 2 is a cross-sectional view of the substrate in the ceramic structure according to the first embodiment. FIG. 3 is a front view of the substrate in the ceramic structure according to the first embodiment. FIG. 4 is a cross-sectional view of the substrate in the ceramic structure according to the second embodiment. FIG. 5 is a cross-sectional view of the substrate in the ceramic structure according to the third embodiment. FIG. 6 is a cross-sectional view of the substrate in the ceramic structure according to the fourth embodiment. FIG. 7 is a cross-sectional view showing a modified example of the configuration of the substrate in the ceramic structure according to the fourth embodiment. FIG. 8 is a cross-sectional view of the substrate in the ceramic structure according to the fifth embodiment. FIG. 9 is a perspective view of the substrate in the ceramic structure according to the sixth embodiment. FIG. 10 is a cross-sectional view of the substrate in the ceramic structure according to the sixth embodiment. FIG. 11 is a cross-sectional view of the substrate in the ceramic structure according to the seventh embodiment. FIG. 12 is a cross-sectional view of the substrate in the ceramic structure according to the eighth embodiment.

[0006] Conventionally, a structure has been disclosed in which an aerogel, an example of an insulating material, is positioned between a flexible film heater and an outer tube housing the film heater. In such a structure, it may be difficult to provide insulating material to the structure due to structural or dimensional constraints, for example. Therefore, the above-mentioned conventional technology has room for improvement in terms of providing insulating function without using insulating material.

[0007] This disclosure provides a ceramic structure having thermal insulation properties.

[0008] The embodiments for carrying out the ceramic structure according to this disclosure (hereinafter referred to as "embodiments") will be described in detail below with reference to the drawings. However, this disclosure is not limited by these embodiments. Furthermore, each embodiment can be combined as appropriate, provided that the processing details are not inconsistent. Also, the same parts are denoted by the same reference numerals in each of the following embodiments, and redundant descriptions are omitted.

[0009] Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require strict adherence to "constant," "orthogonal," "perpendicular," or "parallel" conditions. In other words, each of the above expressions allows for deviations, for example, in manufacturing accuracy or installation accuracy.

[0010] <First Embodiment> (Configuration of Ceramic Structure) First, the configuration of the ceramic structure according to the first embodiment will be described with reference to Figures 1 to 3. Figure 1 is a perspective view of the substrate 1 in the ceramic structure 100 according to the first embodiment.

[0011] The ceramic structure 100 of this disclosure may have, for example, a rod-shaped substrate 1 as shown in Figure 1. The substrate 1 is made of ceramics. For example, the substrate 1 may be made of any of the following: an alumina sintered body, a zirconia sintered body, a cordierite sintered body, a silicon carbide sintered body, a silicon nitride sintered body, and an aluminum nitride sintered body.

[0012] The base 1 may have a first surface 11, a second surface 12 located opposite the first surface 11, and a side surface 13 connecting the first surface 11 and the second surface 12. The first surface 11 and the second surface 12 may be, for example, circular in plan view. In other words, the base 1 may be a round bar-shaped member having a cylindrical shape.

[0013] As shown in Figure 1, the first surface 11 may have a first opening 21 that communicates with the internal space 2 (described later) and a third opening 31 that communicates with the heat-insulating space 3 (described later). There may be multiple third openings 31. For example, Figure 1 shows an example where two third openings 31 are located on the first surface 11. Details of the configuration of the base 1 will be described later with reference to Figures 2 and 3.

[0014] Figure 2 is a cross-sectional view of the substrate 1 in the ceramic structure 100 according to the first embodiment. Specifically, Figure 2 shows a cross-sectional view of the substrate 1 along the dashed line connecting L1 and L2 shown in Figure 1. As shown in Figure 2, the substrate 1 may have an internal space 2 extending from the first surface 11 toward the second surface 12. Specifically, the internal space 2 may be, for example, a cylindrical space.

[0015] The internal space 2 may be open to the first surface 11. Specifically, the internal space 2 may be in communication with a first opening 21 located on the first surface 11 (an example of a second opening of the internal space 2 located on the first surface 11). The first opening 21 may be located, for example, in the center of the first surface 11.

[0016] The internal space 2 may be a through-hole penetrating the first surface 11 and the second surface 12. Specifically, the internal space 2 may communicate with a first opening 21 located on the first surface 11 and with a second opening 22 located on the second surface 12. The internal space 2 may also be a through-hole extending linearly from the first opening 21 to the second opening 22. However, the internal space 2 does not necessarily have to extend linearly. This point will be discussed later.

[0017] The base 1 may have an insulating space 3 located between the internal space 2 and the side surface 13. The insulating space 3 may be a closed space on the second surface 12 side. Specifically, the insulating space 3 may be an opening at the first surface 11 and extend from the first surface 11 toward the second surface 12.

[0018] The thermal conductivity of the insulating space 3, i.e., the air layer, is lower than the thermal conductivity of the ceramics constituting the substrate 1. Therefore, with a ceramic structure 100 having such an insulating space 3, the diffusion of heat from the internal space 2 to the outside of the substrate 1 can be reduced compared to a structure without an insulating space 3. For example, when a relatively hot fluid is circulated in the internal space 2, heat from the fluid is less likely to diffuse to the outside of the substrate 1. Similarly, the intrusion of heat from the outside of the substrate 1 into the internal space 2 can also be reduced.

[0019] The shape of the thermal insulation space 3 according to the first embodiment will be described with further reference to Figure 3. Figure 3 is a front view of the base body 1 in the ceramic structure 100 according to the first embodiment. Specifically, Figure 3 corresponds to a plan view of the ceramic structure 100 according to the first embodiment as seen from the first surface 11 side. The area shown by the dashed line in Figure 3 indicates the cylindrical space portion in the thermal insulation space 3.

[0020] As shown in Figures 2 and 3, the thermal insulation space 3 may have a plurality of third openings 31 located on the first surface 11 (an example of the first openings of the thermal insulation space 3 located on the first surface 11), a first bottom surface 32 which is the surface facing the second surface 12, and a side wall surface 33 connecting the first bottom surface 32 and the first surface 11.

[0021] As shown by the dashed line in Figure 3, the thermal insulation space 3 may, for example, have a cylindrical space surrounding the internal space 2. This cylindrical space communicates with multiple, in this case two, third openings 31 on the first surface 11.

[0022] The opening area of ​​the third opening 31 may be smaller than the cross-sectional area of ​​the cylindrical space portion in the insulated space 3 in a section parallel to the first surface 11. With this configuration, it is difficult for unwanted foreign matter or fluids to enter the interior of the insulated space 3 through the third opening 31.

[0023] In the first embodiment, a contactless communication medium such as an RFID (Radio Frequency Identification) tag (not shown) may be housed inside the insulated space 3. Such an RFID may be used, for example, to identify the material on which the ceramic structure 100 is mounted.

[0024] <Second Embodiment> Next, the configuration of the ceramic structure 100 according to the second embodiment will be described with reference to Figure 4. Figure 4 is a cross-sectional view of the substrate 1 in the ceramic structure 100 according to the second embodiment. As shown in Figure 4, the heat insulating space 3 may have through holes 34 that communicate with the heat insulating space 3 and the surface of the substrate 1.

[0025] Specifically, the ceramic structure 100 may have a through hole 34 that opens at one end in the first bottom surface 32 or the side wall surface 33 and at the other end in the surface of the base body 1. There may be multiple through holes 34, and in Figure 4, two are provided. Specifically, in the base body 1, the through hole 34 is provided at a position opposite to the third opening 31.

[0026] The cross-sectional area of ​​the through-hole 34 may be smaller than the cross-sectional area of ​​the thermal insulation space 3 in a section parallel to the first surface 11. With this configuration, for example, if a fluid flows from the third opening 31, the fluid can be discharged to the outside of the thermal insulation space 3. Even if the first bottom surface 32 has a through-hole 34, as long as the first bottom surface 32 is present, the thermal insulation space 3 is considered to be a closed space on the second surface 12 side.

[0027] <Third Embodiment> Next, the configuration of the ceramic structure 100 according to the third embodiment will be described with reference to Figure 5. Figure 5 is a cross-sectional view of the base body 1 in the ceramic structure 100 according to the third embodiment. In the first and second embodiments, an example was described in which the internal space 2 is a through hole. However, the internal space 2 may be a closed space on the second surface 12 side.

[0028] Specifically, the internal space 2 according to the third embodiment may have a second bottom surface 23 located opposite the first opening 21, and a side wall surface 24 connecting the second bottom surface 23 and the first opening 21.

[0029] A ceramic structure 100 having such a configuration can be used as a temperature control device by, for example, equipping the internal space 2 with a temperature control element such as a resistance heating element or a Peltier element.

[0030] As shown in Figure 5, when L1 is the distance between the first bottom surface 32 and the second surface 12 of the insulating space 3 along the direction perpendicular to the first surface 11, and L2 is the distance between the second bottom surface 23 and the second surface 12 of the internal space 2, L2 may be greater than L1. In other words, the length of the insulating space 3 in the extending direction may be greater than the length of the internal space 2 in the extending direction. With such a configuration, it becomes easier to block the heat exchange between the second bottom surface 23 and the side surface 13 of the base 1, resulting in a superior insulating effect.

[0031] <Fourth Embodiment> Next, the configuration of the ceramic structure 100 according to the fourth embodiment will be described with reference to Figures 6 and 7. Figure 6 is a cross-sectional view of the substrate 1 in the ceramic structure 100 according to the fourth embodiment. The ceramic structure 100 according to the fourth embodiment may have a metal wiring layer 4 (an example of metal wiring) located between the internal space 2 and the heat insulating space 3. That is, the ceramic structure 100 according to the fourth embodiment corresponds to the configuration of the ceramic structure 100 according to the second embodiment in which a metal wiring layer 4 is provided.

[0032] As shown in Figure 6, the metal wiring layer 4 may extend from the first surface 11 to the second surface 12 between the internal space 2 and the heat insulating space 3. Specifically, the metal wiring layer 4 may be arranged spirally between the internal space 2 and the heat insulating space 3, surrounding the internal space 2. The metal wiring layer 4 functions as a heat-generating resistor. The metal wiring layer 4 may be a metal conductor mainly composed of, for example, platinum, tungsten, molybdenum, copper, or silver.

[0033] As shown in Figure 6, a metal terminal 5 may be inserted into the heat-insulating space 3. Specifically, the metal terminal 5 may be inserted through the third opening 31 of the heat-insulating space 3. The metal terminal 5 may have, for example, a metal terminal 5a connected to the positive terminal of a power supply (not shown) and a metal terminal 5b connected to the negative terminal of a power supply (not shown). In the fourth embodiment, the metal terminal 5a is inserted into one of the two third openings 31 and the metal terminal 5b is connected to the other.

[0034] The metal terminals 5a and 5b and the metal wiring layer 4 may be electrically connected within the heat-insulating space 3 by, for example, a conductive bonding material (not shown). The conductive bonding material may contain a metallic material such as silver, copper, or tin. In this case, a portion of the metal wiring layer 4 may be exposed to the inside of the heat-insulating space 3 by peeling off the end of the inner side wall surface 33 of the heat-insulating space 3 that is on the side of the first surface 11. The exposed portion of the metal wiring layer 4 may then be electrically connected to the metal terminals 5a and 5b.

[0035] In the ceramic structure 100 having a metal wiring layer 4, the metal wiring layer 4 can be heated by passing an electric current through it. This allows the fluid or other material flowing through the internal space 2 to be heated. In this case as well, the heat-insulating space 3 reduces the diffusion of heat from the metal wiring layer 4 to the outside of the substrate 1.

[0036] Furthermore, the third opening 31 into which the metal terminals 5a and 5b are inserted may be sealed with an organic resin or the like (not shown). The organic resin may be, for example, epoxy resin, acrylic resin, polycarbonate resin, polyimide resin, olefin resin, or polyphenylene resin. With this configuration, it is difficult for unwanted foreign matter or fluids to enter through the gap in the third opening 31.

[0037] Next, a modified example of the ceramic structure 100 according to the fourth embodiment will be described with reference to Figure 7. Figure 7 is a cross-sectional view showing a modified example of the configuration of the substrate 1 in the ceramic structure 100 according to the fourth embodiment.

[0038] As shown in Figure 7, the metal wiring layer 4 may be located, for example, on the inner circumferential surface of the side wall surface 33 of the heat insulating space 3. In this case, the metal wiring layer 4 may be, for example, a metal wire. When a metal wire is used as the metal wiring layer 4, the metal wiring may be inserted into the heat insulating space 3 from the third opening 31. The metal wire may be joined to the side wall surface 33 with, for example, a soldering material. In this case, the metal terminals 5a and 5b may be connected to the metal wire, for example, outside the base body 1.

[0039] <Fifth Embodiment> Next, the configuration of the ceramic structure 100 according to the fifth embodiment will be described with reference to Figure 8. Figure 8 is a cross-sectional view of the substrate 1 in the ceramic structure 100 according to the fifth embodiment. The ceramic structure 100 according to the fifth embodiment may have a metal electrode 6 inserted into the internal space 2. That is, the ceramic structure 100 according to the fifth embodiment corresponds to the configuration of the ceramic structure 100 according to the second embodiment in which a metal electrode 6 is provided.

[0040] The metal electrode 6 may be, for example, a rod-shaped member. Such a metal electrode 6 may have one end connected to the positive electrode of a power supply (not shown) and the other end connected to the negative electrode of a power supply (not shown). By passing an electric current through the metal electrode 6, the metal electrode can be heated. In other words, the metal electrode 6 functions as a heat-generating resistor.

[0041] A ceramic structure 100 having such a configuration can be used, for example, when heating an object at the tip of a metal electrode 6. Specifically, it can be used, for example, in an electrosurgical unit. According to the ceramic structure 100 of the fifth embodiment, the heat-insulating space 3 reduces the diffusion of heat generated in parts other than the tip of the metal electrode 6 to the outside of the base body 1. Therefore, problems such as the object being heated by heat from the side surface 13 of the base body 1 are less likely to occur.

[0042] If the second surface 12 side of the internal space 2 is closed, the metal electrodes 6 connected to the positive and negative electrodes of the power supply may be inserted through the first opening 21.

[0043] <6th Embodiment> Next, the configuration of the ceramic structure 100 according to the 5th embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is a perspective view of the substrate 1 in the ceramic structure 100 according to the 6th embodiment. FIG. 10 is a cross-sectional view of the substrate 1 in the ceramic structure 100 according to the 6th embodiment.

[0044] In the 1st to 5th embodiments, an example in which the heat insulation space 3 has a cylindrical space portion has been described. On the other hand, as shown in FIGS. 9 and 10, the heat insulation space 3 in the 6th embodiment may be a cylindrical space in which the shape of the cross-section orthogonal to the 1st surface 11 is circular.

[0045] As shown in FIG. 10, when the interval between the internal space 2 and the heat insulation space 3 is D, such interval D may vary along the direction orthogonal to the 1st surface 11. In other words, for example, the heat insulation space 3 may be bent with respect to the direction orthogonal to the 1st surface 11. Further, not limited to this, the internal space 2 may be bent with respect to the direction orthogonal to the 1st surface 11, or both the internal space 2 and the heat insulation space 3 may be bent with respect to the direction orthogonal to the 1st surface 11. The ceramic structure 100 having such a configuration has a high degree of design freedom. Therefore, the range of uses of the ceramic structure 100 can be widened.

[0046] In FIG. 10, an example in which the cross-sectional area of the heat insulation space 3 in the cross-section orthogonal to the 1st surface 11 is constant is illustrated, but not limited to this. For example, the cross-sectional area of the heat insulation space 3 may vary along the direction from the 1st surface 11 toward the 2nd surface 12. The ceramic structure 100 having such a configuration has an even higher degree of design freedom. Therefore, the range of uses of the ceramic structure 100 can be widened.

[0047] <7th Embodiment> Next, the configuration of the ceramic structure 100 according to the 7th embodiment will be described with reference to FIG. 11. FIG. 11 is a cross-sectional view of the substrate 1 in the ceramic structure 100 according to the 7th embodiment. The ceramic structure 100 according to the 7th embodiment may have an accommodation space 8 for accommodating the RFID tag 7. That is, the ceramic structure 100 according to the 7th embodiment corresponds to the configuration in which the accommodation space 8 is provided in the ceramic structure 100 according to the 2nd embodiment.

[0048] As shown in FIG. 11, the accommodation space 8 may be formed, for example, by closing a recess provided on the side surface 13 of the substrate 1 with a lid body 9. The lid body 9 may be fixed to the substrate 1 by a fixing mechanism (not shown), for example. The RFID tag 7 may be accommodated inside such an accommodation space 8.

[0049] Note that the lid body 9 is preferably made of a material having radio wave permeability. For example, it may be the same ceramic as the main component of the ceramic structure 100. Also, the RFID tag 7 may be surrounded by a heat insulating material and installed in the accommodation space 8.

[0050] The accommodation space 8 is not limited to the example in FIG. 11. For example, it may be located on the first surface 11 or the second surface 12 of the substrate 1, or may be located between the third opening 31 and the first opening 21. Also, the shape of the accommodation space 8 is not particularly limited.

[0051] <8th Embodiment> Next, the configuration of the ceramic structure 100 according to the 8th embodiment will be described with reference to FIG. 12. FIG. 12 is a cross-sectional view of the substrate 1 in the ceramic structure 100 according to the 8th embodiment.

[0052] In the 1st to 7th embodiments, examples in the case where the heat insulating space 3 has the third opening 31 and the through hole 34 have been described. On the other hand, as shown in FIG. 12, the heat insulating space 3 in the 8th embodiment may not have the third opening 31 and the through hole 34. That is, the heat insulating space 3 may be a sealed space.

[0053] (Manufacturing Method) Next, an example of a manufacturing method for the ceramic structure 100 according to the first to eighth embodiments will be described. First, a primary molded body made of ceramic material that forms the ceramic structure 100 having an internal space 2 is produced. The primary molded body may be produced by, for example, injection molding, extrusion molding, powder pressing, etc. Alternatively, the primary molded body may be made by winding a ceramic green sheet to create a space that forms the internal space 2.

[0054] Furthermore, as shown in Figures 6 and 7 above, if the substrate 1 has a metal wiring layer 4, then metal paste can be printed on the outside of the primary molded body or metal wire can be wound around it. Also, as shown in Figure 8 above, if the substrate 1 has a metal electrode 6, then metal powder or metal paste can be filled into the internal space 2, or a metal sintered body can be inserted.

[0055] On the other hand, cores having the same shape as the insulating space 3 located inside the base 1 are fabricated. The cores may be made of, for example, a thermoplastic resin.

[0056] Examples of thermoplastic resins that can be used include polyacetal resin, polypropylene resin, polyethylene resin, polyamide resin, polymethyl methacrylate resin, polystyrene resin, styrene-acrylic copolymer resin, ethylene vinyl acetate copolymer resin, ethylene butyl methacrylate copolymer resin, polyethylene terephthalate resin, and polylactic acid resin.

[0057] Next, the primary molded body and core are placed inside a metal mold or the like that has been molded to the outer shape of the base body 1. Then, an injection molding method is performed in which a compound consisting of ceramic material and thermoplastic resin is poured into the inside of the mold. This fills the gap between the primary molded body and the core with the compound. After that, when the mold is cooled, the compound hardens and the primary molded body and the core are bonded together. This forms a secondary molded body having the shape of the mold. If the main component of the ceramics in the compound at this time is the same as the main component of the ceramics in the primary molded body, the sintering bonding properties in the sintering process described later will be improved, and the mechanical properties of the base body 1 will be excellent.

[0058] Finally, the secondary molded body is subjected to a sintering process to form the ceramic structure 100. During this sintering process, the core, which is made of thermoplastic resin located inside the secondary molded body, is thermally decomposed and removed. This makes it possible to form a ceramic structure 100 having an internal space 2 and an insulating space 3.

[0059] The core may be removed before sintering the secondary molded body. Specifically, for example, the core may be removed by thermal decomposition by heating the secondary molded body at a temperature at which the plastic resin decomposes. Alternatively, the core may be removed by dissolving it using water or an organic solvent, for example.

[0060] Alternatively, the internal space 2 may be formed with a core. In this case, the core for forming the internal space 2 and the core for forming the heat insulating space 3 can be placed inside a mold or the like before performing injection molding. This eliminates the step of producing the primary molded body and simplifies the manufacturing method.

[0061] According to this manufacturing method, for example, a ceramic structure 100 having a desired shape can be formed by appropriately changing the shapes of the primary molded body, core, and mold.

[0062] <Examples of applications of the ceramic structure of this disclosure> The configuration of the ceramic structure 100 of this disclosure has been described so far. Specific examples of applications of the ceramic structure 100 of this disclosure include, for example, nozzles for discharging heated fluids and electrosurgical units.

[0063] Although the present disclosure has been described in detail above, this disclosure is not limited to the embodiments described above, and various modifications and improvements are possible without departing from the gist of this disclosure.

[0064] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0065] Furthermore, this technology can also take the following configurations: (1) A ceramic structure comprising a base made of ceramics, having a first surface, a second surface located opposite to the first surface, and a side surface connecting the first surface and the second surface; an internal space opening to the first surface and extending from the first surface toward the second surface; and a thermal insulation space located between the internal space and the side surface, wherein the thermal insulation space is a closed space on the side of the second surface. (2) The ceramic structure according to (1), wherein the thermal insulation space opening to the first surface and extending from the first surface toward the second surface. (3) The ceramic structure according to (2), wherein the insulating space has a first opening located on the first surface, a first bottom surface located opposite the first opening, and a side wall surface connecting the first bottom surface and the first surface, and further has a through hole having one end opening to the first bottom surface or the side wall surface and the other end opening to the surface of the base, and the cross-sectional area of ​​the through hole is smaller than the cross-sectional area of ​​the insulating space. (4) The ceramic structure according to (2) or (3), wherein the insulating space is a cylindrical space surrounding the internal space. (5) The ceramic structure according to (4), wherein the insulating space has a first opening located on the first surface, and the opening area of ​​the first opening is smaller than the cross-sectional area of ​​the cylindrical space portion in the insulating space. (6) The ceramic structure according to any one of (1) to (5), wherein the internal space opens to the first surface and the second surface. (7) The ceramic structure according to any one of (1) to (5), wherein the insulating space has a first opening located on the first surface and a first bottom surface located opposite the first opening, the internal space has a second opening located on the first surface and a second bottom surface located opposite the second opening, and the distance between the first bottom surface and the second surface is smaller than the distance between the second bottom surface and the second surface. (8) The ceramic structure according to any one of (1) to (7), wherein it has metal wiring located between the internal space and the insulating space and extending from the first surface toward the second surface. (9) The ceramic structure according to (8), wherein it has metal terminals inserted into the insulating space and electrically connected to the metal wiring.(10) A ceramic structure according to any one of (1) to (7), having an electrode inserted into the internal space. (11) A ceramic structure according to any one of (1) to (10), wherein the distance between the internal space and the insulating space varies along a direction perpendicular to the first surface. (12) A ceramic structure according to any one of (1) to (11), having an RFID tag located inside the insulating space.

[0066] 1 Base 2 Internal space 3 Thermal insulation space 4 Metal wiring layer 5, 5a, 5b Metal terminals 6 Metal electrodes 7 RFID tag 8 Housing space 9 Cover 11 First surface 12 Second surface 13 Side 21 First opening (an example of the second opening of the internal space located on the first surface) 22 Second opening 23 Second bottom surface 24, 33 Side wall surfaces 31 Third opening (an example of the first opening of the thermal insulation space 3 located on the first surface) 32 First bottom surface 34 Through hole 100 Ceramic structure

Claims

1. A ceramic structure comprising a base made of ceramics, having a first surface, a second surface located opposite the first surface, and a side surface connecting the first surface and the second surface; an internal space opening to the first surface and extending from the first surface toward the second surface; and a thermal insulation space located between the internal space and the side surface, wherein the thermal insulation space is a closed space on the side of the second surface.

2. The ceramic structure according to claim 1, wherein the thermal insulation space opens to the first surface and extends from the first surface toward the second surface.

3. The ceramic structure according to claim 2, wherein the thermal insulation space has a first opening located on the first surface, a first bottom surface located opposite the first opening, and a side wall surface connecting the first bottom surface and the first surface, and further has a through hole having one end opening to the first bottom surface or the side wall surface and the other end opening to the surface of the substrate, and the cross-sectional area of ​​the through hole is smaller than the cross-sectional area of ​​the thermal insulation space.

4. The ceramic structure according to claim 2 or 3, wherein the thermal insulation space is a cylindrical space surrounding the internal space.

5. The ceramic structure according to claim 4, wherein the thermal insulation space has a first opening located on the first surface, and the opening area of ​​the first opening is smaller than the cross-sectional area of ​​the cylindrical space portion in the thermal insulation space.

6. The ceramic structure according to any one of claims 1 to 5, wherein the internal space opens to the first surface and the second surface.

7. The ceramic structure according to any one of claims 1 to 5, wherein the thermal insulation space has a first opening located on the first surface and a first bottom surface located opposite the first opening, the internal space has a second opening located on the first surface and a second bottom surface located opposite the second opening, and the distance between the first bottom surface and the second surface is smaller than the distance between the second bottom surface and the second surface.

8. The ceramic structure according to any one of claims 1 to 7, wherein it has metal wiring located between the internal space and the thermal insulation space and extending from the first surface toward the second surface.

9. The ceramic structure according to claim 8, having a metal terminal inserted into the heat insulating space and electrically connected to the metal wiring.

10. A ceramic structure according to any one of claims 1 to 7, having an electrode inserted into the internal space.

11. The ceramic structure according to any one of claims 1 to 10, wherein the distance between the internal space and the insulating space varies along a direction perpendicular to the first surface.

12. A ceramic structure according to any one of claims 1 to 11, having an RFID tag located inside the insulated space.

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