Thermal devices

Abstract

A thermal device according to the present disclosure comprises a ceramic container, a fluid, and a metal tube. The container has an internal space, an opening that is in communication with the internal space, and a communication path that connects the internal space and the opening. The fluid is located in the internal space. A part of the metal tube is inserted in the communication path, and another part of the metal tube is closed.

Description

Technical Field

[0001] This disclosure relates to thermal devices.

Background Art

[0002] Conventionally, thermal devices that utilize the latent heat of phase change materials have been known. Patent Document 1 discloses a heat pipe including a sealed container and a pipe for injecting a working fluid into the interior of the sealed container.

[0003] Moreover, Patent Document 1 discloses that the sealed container and the pipe are formed of a metal with excellent heat conductivity.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] A thermal device according to one aspect of this disclosure includes a ceramic container, a fluid, and a metal pipe. The container has an internal space, an opening connected to the internal space, and a communication path connecting the internal space and the opening. The fluid is located in the internal space. The metal pipe Through the opening is partially inserted into the communication path and the other part is closed. There are multiple openings, passages, and metal tubes, with one metal tube inserted into each of the passages, and the multiple openings are located on the sides of the container.

Brief Description of the Drawings

[0006] [Figure 1] FIG. 1 is a perspective view of a heat dissipation device according to an embodiment. [Figure 2] FIG. 2 is a view of a first member according to an embodiment as seen from the negative Z-axis side toward the positive Z-axis. [Figure 3] [[ID=5,3]]FIG. 3 is a view of a second member according to an embodiment as seen from the positive Z-axis side toward the negative Z-axis. [Figure 4]Figure 4 is a view of the intermediate member according to the embodiment, seen from the positive Z-axis direction to the negative Z-axis direction. [Figure 5] Figure 5 shows the first groove-forming region and the second groove-forming region superimposed on the intermediate member. [Figure 6] Figure 6 is a diagram illustrating the fluid flow in the heat dissipation device according to the embodiment. [Figure 7] Figure 7 is a diagram illustrating the fluid flow in the heat dissipation device according to the embodiment. [Figure 8] Figure 8 is a cross-sectional view taken along the line VIII-VIII in Figure 5. [Figure 9] Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 8. [Figure 10] Figure 10 is a schematic diagram showing an example of pressure welding of metal pipes. [Figure 11] Figure 11 is a schematic diagram showing the first modified example. [Modes for carrying out the invention]

[0007] The embodiments for implementing the thermal device 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 content is not inconsistent. Also, the same parts are denoted by the same reference numerals in each of the following embodiments, and redundant descriptions are omitted.

[0008] 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 such as manufacturing accuracy or installation accuracy.

[0009] Furthermore, in the drawings referenced below, for the sake of clarity, mutually orthogonal X, Y, and Z axis directions are sometimes defined, and a Cartesian coordinate system is shown with the positive Z axis pointing vertically upward.

[0010] The technology described in Patent Document 1 had room for further improvement in terms of enhancing durability.

[0011] This disclosure has been made in view of the above, and provides a thermal device with excellent durability.

[0012] In the following, as an example of a thermal device according to this disclosure, we will describe a heat dissipation device that efficiently transfers heat from a high-temperature area to a low-temperature area by utilizing the latent heat associated with the evaporation and condensation of a fluid (an example of a working fluid or a phase-transforming material), specifically a vapor chamber. Hereafter, the thermal device may be referred to as a heat dissipation device.

[0013] First, the overall configuration of the heat dissipation device according to the embodiment will be described with reference to Figure 1. Figure 1 is a perspective view of the heat dissipation device according to the embodiment.

[0014] As shown in Figure 1, the heat dissipation device 1 may have a container 2. The container 2 may be made of ceramic. The container 2 may have a first member 10, a second member 20, and an intermediate member 30. The first member 10, the second member 20, and the intermediate member 30 may all be plate-shaped, and the intermediate member 30 may be sandwiched between the first member 10 and the second member 20.

[0015] Furthermore, the container 2 may have a first reinforcing member 40 and a second reinforcing member 50. The first reinforcing member 40 may be located on the upper surface (the fifth surface) of the first member 10. The first reinforcing member 40 may be, for example, a laminate of two reinforcing plates 40a and 40b. Without being limited to this, the first reinforcing member 40 may be composed of a single reinforcing plate. The second reinforcing member 50 may be located on the lower surface (the sixth surface) of the second member 20. The second reinforcing member 50 may be, for example, a laminate of two reinforcing plates 50a and 50b. Without being limited to this, the second reinforcing member 50 may be composed of a single reinforcing plate.

[0016] Note that the container 2 does not necessarily have to have the first reinforcing member 40 and the second reinforcing member 50.

[0017] The container 2 may have an operating region 100 and a frame region 200. The operating region 100 may be an internal space formed in the container 2, and a fluid as a phase change material may be enclosed in such an internal space. As the fluid, for example, liquids such as water, hydrocarbon-based compounds, organic liquids (such as ethanol and methanol), and ammonia may be used.

[0018] When the container 2 is viewed through in a direction perpendicular to the upper surface of the container 2 (that is, when the container 2 is viewed in a plane perspective), the shape of the operating region 100 may be circular. Specifically, the operating region 100 may have a cylindrical shape. With such a configuration, compared with the case where the shape of the operating region 100 is rectangular in a plan view, stress concentration at the corners is less likely to occur. Therefore, according to the heat dissipation device 1 according to the embodiment, for example, the durability of the container 2 against stress generated by the phase change of the fluid can be improved.

[0019] Also, with such a configuration, compared with the case where the shape of the operating region 100 is rectangular in a plan view, the cross-sectional area of the portion where the communication path 60 described later is connected to the operating region 100 becomes larger, so that the injection of the fluid and the discharge of the gas in the operating region 100 can be performed more efficiently.

[0020] The frame region 200 may be the region surrounding the operating region 100. In other words, the frame region 200 may be the region of the heat dissipation device 1 that is outside the operating region 100. The operating region 100 may be generally hollow, while the frame region 200 may be generally solid.

[0021] The frame region 200 is a region that is deliberately made wide in order to reduce leakage of fluid or fluid vapor from, for example, the interface between the first member 10 and the intermediate member 30 or the interface between the second member 20 and the intermediate member 30, or to reduce the intrusion of the external atmosphere into the internal space of the working region 100 from the above interfaces (i.e., to ensure airtightness).

[0022] The fluid may be filled in a proportion of 10% to 95% of the total volume of the internal space of the working region 100. Preferably, the proportion may be 30% to 75%. More preferably, the proportion may be 40% to 65%. In addition, the remaining portion of the internal space of the working region 100 other than the fluid may be in a vacuum or low-pressure state containing a portion of the vaporized fluid. This allows for maintaining vapor-liquid equilibrium even in high-temperature environments, making it less prone to drying out, and also allows for efficient heat diffusion even in low-temperature environments, thus enabling high thermal diffusivity in a variety of temperature ranges.

[0023] The first member 10, the second member 20, the intermediate member 30, the first reinforcing member 40, and the second reinforcing member 50 may be made of ceramic. Examples of ceramics that make up the first member 10, the second member 20, the intermediate member 30, the first reinforcing member 40, and the second reinforcing member 50 include alumina (Al2O3), zirconia (ZrO2), silicon carbide (SiC), silicon nitride (Si3N4), aluminum nitride (AlN), cordierite (Mg2Al3(AlSi5O 18 )), silicon-impregnated silicon carbide (SiSiC) may be used. Also, the ceramics constituting the first member 10, the second member 20, the intermediate member 30, the first reinforcing member 40, and the second reinforcing member 50 may be single crystals.

[0024] Metal heat dissipation devices have difficulty achieving rigidity and miniaturization due to material and manufacturing constraints. Furthermore, because the parts of metal heat dissipation devices that come into contact with the fluid are metal, there is room for improvement in terms of corrosion resistance. In contrast, the heat dissipation device 1 according to this embodiment is made entirely of ceramic, including the first member 10, the second member 20, the intermediate member 30, the first reinforcing member 40, and the second reinforcing member 50. Therefore, it is easier to miniaturize compared to metal heat dissipation devices, and it also has superior corrosion resistance.

[0025] In the example shown in Figure 1, the heat dissipation device 1 is installed with the first member 10 facing upwards, but the orientation of the heat dissipation device 1 is not limited to the example in Figure 1. For example, the heat dissipation device 1 may be installed with the first member 10 facing downwards. Also, the heat dissipation device 1 may be installed vertically, not just horizontally as shown in Figure 1.

[0026] The container 2 may have a plurality (in this case, two) of communication passages 60 that connect the internal space of the working region 100 to the outside. One of the two communication passages 60 may be used, for example, as an injection port for injecting fluid. The other of the two communication passages 60 may be used, for example, as an exhaust port for discharging gas from within the working region 100. In this case, during the manufacturing process of the heat dissipation device 1, fluid may be injected into the internal space of the working region 100 from one of the communication passages 60, and consequently, gas present in the internal space of the working region 100 may be discharged to the outside from the other communication passage 60.

[0027] The two connecting passages 60 may open to the side of the container 2. The two connecting passages 60 may extend linearly from the side of the container 2 toward the working area 100.

[0028] The two connecting passages 60 may open on the same side of the container 2. In this case, by orienting the side on which the two connecting passages 60 open upwards, fluid can be efficiently injected into the working region 100, and gas present in the internal space of the working region 100 can be efficiently discharged.

[0029] A heat source may be placed on the top surface of container 2. Therefore, by positioning the communication passage 60 on the side of container 2, a larger space for installing the heat source can be secured compared to the case where the communication passage 60 is located on the top surface of container 2.

[0030] The two communication passages 60 may open to different sides of the container 2. Furthermore, the heat dissipation device 1 does not necessarily need to have multiple communication passages 60. For example, the heat dissipation device 1 may have only one of the two communication passages 60 described above.

[0031] A metal tube 70 is inserted into the communication passage 60, and the communication passage 60 may be sealed by this metal tube 70. When the communication passage 60 is closed by the metal tube 70, the internal space of the heat dissipation device 1 is sealed, and the fluid is sealed within the operating region 100. Thus, the heat dissipation device 1 may be a sealed container with an internally sealed structure. The specific configuration of the communication passage 60 and the metal tube 70 will be described later.

[0032] Next, the configuration of the first member 10 will be described with reference to Figure 2. Figure 2 is a view of the first member 10 according to the embodiment, seen from the negative Z-axis direction to the positive Z-axis direction.

[0033] Figure 2 shows the lower surface of the first member 10, specifically the surface (third surface) facing the upper surface (first surface) of the intermediate member 30. As shown in Figure 2, the first member 10 may have a grid-like first groove 11 on the third surface.

[0034] The first groove 11 may have a first recess 11a that is recessed relative to the third surface, and a plurality of first protrusions 11b located within the first recess 11a. The first recess 11a is located in the center of the third surface, and its contour in plan view may be, for example, circular. The plurality of first protrusions 11b may be arranged vertically and horizontally with spacing between them within the first recess 11a. Due to these first recesses 11a and the plurality of first protrusions 11b, the first groove 11 may have a grid-like structure.

[0035] Hereinafter, the region of the third surface of the first member 10 where the first groove 11 is located will be referred to as the "first groove forming region 110". The first groove forming region 110 may constitute a part of the operating region 100. The first member 10 may also have a rectangular frame-shaped first frame region 210 surrounding the first groove forming region 110. The first frame region 210 may constitute a part of the frame region 200.

[0036] Multiple (in this case, two) communication grooves 12 may be located in the first frame region 210. The communication grooves 12 may constitute part of the communication passage 60. One end of the communication groove 12 may be located on the outer edge of the first member 10, and the other end of the communication groove 12 may be located on the outer edge of the first recess 11a. The depth of the communication groove 12 in the thickness direction (in this case, the Z-axis direction) of the first member 10 may be deeper than the depth of the first recess 11a in the thickness direction of the first member 10.

[0037] The reinforcing plate 40b of the first reinforcing member 40 described above may be located in the center of the upper surface (fifth surface) of the first member 10, which is located opposite the lower surface (third surface).

[0038] Next, the configuration of the second member 20 will be described with reference to Figure 3. Figure 3 is a view of the second member 20 according to the embodiment, seen from the positive Z-axis direction to the negative Z-axis direction.

[0039] Figure 3 shows the upper surface of the second member 20, specifically the surface (fourth surface) facing the lower surface (second surface) of the intermediate member 30. As shown in Figure 3, the second member 20 has a grid-like second groove 21 on its fourth surface.

[0040] The second groove 21 may have a second recess 21a that is recessed relative to the fourth surface, and a plurality of second protrusions 21b located within the second recess 21a. The second recess 21a may be located in the center of the fourth surface, and its contour in plan view may be, for example, circular. The plurality of second protrusions 21b may be arranged vertically and horizontally with spacing between them within the second recess 21a. Due to these second recesses 21a and the plurality of second protrusions 21b, the second groove 21 may have a grid-like structure.

[0041] Hereinafter, the region on the fourth surface of the second member 20 where the second groove 21 is located will be referred to as the "second groove forming region 120". The second groove forming region 120 may constitute a part of the operating region 100. The second member 20 may also have a rectangular frame-shaped second frame region 220 surrounding the second groove forming region 120. The second frame region 220 may constitute a part of the frame region 200.

[0042] The size of the second groove-forming region 120 in the second member 20 may be the same as the size of the first groove-forming region 110 in the first member 10. Also, the position of the second groove-forming region 120 on the fourth surface of the second member 20 may be the same as the position of the first groove-forming region 110 on the third surface of the first member 10.

[0043] In this way, by making the shape of the first groove 11 and the second groove 21 grid-like, the fluid can be efficiently circulated within the internal space of the heat dissipation device 1. However, the shape of the first groove 11 and the second groove 21 does not necessarily have to be grid-like.

[0044] Multiple (in this case, two) communication grooves 22 may be located in the second frame region 220. The communication grooves 22 may constitute part of the communication passage 60. One end of the communication groove 22 may be located on the outer edge of the second member 20, and the other end of the communication groove 22 may be located on the outer edge of the second recess 21a. The depth of the communication groove 22 in the thickness direction of the second member 20 may be greater than the depth of the second recess 21a in the thickness direction of the second member 20.

[0045] Next, the configuration of the intermediate member 30 will be described with reference to Figure 4. Figure 4 is a view of the intermediate member 30 according to the embodiment, seen from the positive Z-axis direction to the negative Z-axis direction.

[0046] As shown in Figure 4, the intermediate member 30 may have a rectangular frame-shaped third frame region 230. The third frame region 230 may constitute a part of the frame region 200. The intermediate member 30 may also have a circular central portion 32 in plan view located inside the third frame region 230, and a plurality of connecting portions 33 that are located between the central portion 32 and the third frame region 230 and connect the central portion 32 and the third frame region 230. In the example shown in Figure 4, the central portion 32 may be located in the center of the intermediate member 30. The plurality of connecting portions 33 may extend radially from the central portion 32 toward the third frame region 230, widening as they do so, with intervals between them.

[0047] The intermediate member 30 may further have a plurality of steam holes 36 and a plurality of reflux holes 37. The plurality of steam holes 36 and the plurality of reflux holes 37 may all penetrate the upper surface (first surface) and lower surface (second surface) of the intermediate member 30.

[0048] The multiple steam vents 36 may function as part of the fluid vapor flow path. The multiple steam vents 36 may be located between two adjacent connection portions 33. That is, the multiple steam vents 36 and the multiple connection portions 33 may be alternately located in the circumferential direction. The multiple steam vents 36, like the multiple connection portions 33, may extend radially from the central portion 32 towards the third frame region 230, widening as they are spaced apart from one another.

[0049] Multiple reflux holes 37 may function as part of the fluid flow path. The reflux holes 37 may be fine holes with a smaller opening area compared to the steam holes 36 described above. Specifically, the reflux holes 37 may be small enough to generate capillary action in the fluid passing through them.

[0050] The third frame region 230 may have multiple (in this case, two) communication holes 38. The communication holes 38 may constitute part of the communication passage 60. One end of the communication hole 38 may be located on the outer edge of the intermediate member 30, and the other end of the communication hole 38 may be located on the outer edge of the steam hole 36. The communication holes 38 may penetrate the intermediate member 30 in the thickness direction.

[0051] Figure 5 shows the intermediate member 30 shown in Figure 4 superimposed with the first groove-forming region 110 shown in Figure 2 and the second groove-forming region 120 shown in Figure 3. As shown in Figure 5, the first groove-forming region 110 and the second groove-forming region 120 may overlap with the third frame region 230 of the intermediate member 30.

[0052] The operating region 100 of the heat dissipation device 1 may have an internal space sandwiched between a first groove-forming region 110 and a second groove-forming region 120, and a fluid may be sealed in this internal space. Furthermore, an intermediate member 30 may be interposed between the first groove-forming region 110 and the second groove-forming region 120 within the internal space, thereby dividing the operating region 100 into a first space sandwiched between the first groove-forming region 110 and the intermediate member 30, and a second space sandwiched between the second groove-forming region 120 and the intermediate member 30. These first and second spaces may be connected by steam holes 36 and recirculation holes 37 formed in the intermediate member 30.

[0053] Next, the fluid flow in the heat dissipation device 1 according to the embodiment will be described with reference to Figures 6 and 7. Figures 6 and 7 are diagrams illustrating the fluid flow in the heat dissipation device 1 according to the embodiment. Note that Figure 6 is a diagram from Figure 5 with the third frame region 230 omitted, and Figure 7 is a cross-sectional view taken along the line VII-VII in Figure 6. In Figures 6 and 7, the flow of steam is indicated by white arrows, and the flow of liquid is indicated by black arrows. Also, in Figure 7, the first reinforcing member 40 and the second reinforcing member 50 are omitted.

[0054] The fluid vaporizes into steam when heated by a heat source. As described above, the heat source may be located in the center of the upper surface (fifth surface) of the first member 10 (see Figures 1 and 2). Therefore, the steam from the fluid is generated in the center of the first space (the space sandwiched between the first member 10 and the intermediate member 30).

[0055] The fluid vapor diffuses through the first groove 11 of the first groove-forming region 110 in the in-plane direction (XY plane direction) of the heat dissipation device 1 (see the white arrows shown in Figure 6), and moves through the multiple vapor holes 36 to the second space (the space sandwiched between the second member 20 and the intermediate member 30) (see the white arrows shown in Figure 7).

[0056] The steam that moves to the second space condenses into a liquid due to the decrease in temperature. The liquefied fluid moves towards the center of the heat dissipation device 1 through the second groove-forming region 120 by the capillary force of the second groove 21 (see the black arrow in Figure 6). In this process, the fluid enters the reflux hole 37 and is returned to the first space by the capillary force of the reflux hole 37 (see the black arrow in Figure 7). By repeating this cycle, the heat dissipation device 1 can transfer heat from the heat source.

[0057] Next, the configuration of the metal pipe 70 will be explained with reference to Figure 8. Figure 8 is a cross-sectional view taken along the line VIII-VIII in Figure 5.

[0058] As shown in Figure 8, the communication passage 60 may have communication grooves 12, 22 and communication holes 38. As mentioned above, the depth of the communication groove 12 in the thickness direction (Z-axis direction) of the first member 10 may be deeper than the depth of the first recess 11a of the working region 100 in the thickness direction of the first member 10. Also, the depth of the communication groove 22 in the thickness direction of the second member 20 may be deeper than the depth of the second recess 21a of the working region 100 in the thickness direction of the second member 20. Therefore, the thickness T1 of the working region 100 may be thinner than the thickness T2 of the communication passage 60. With this configuration, the evaporation and condensation cycle of the fluid in the working region 100 (internal space) can be repeated more quickly, and the fluid can be circulated efficiently.

[0059] The metal tube 70 may be partially inserted into the communication passage 60 and the other part closed off to seal the communication passage 60. One end 701 of the metal tube 70 may be located inside the communication passage 60. In other words, the metal tube 70 does not have to be located in the operating region 100. With this configuration, it is possible to reduce the reduction in the effective volume of the operating region 100 (internal space).

[0060] One end 701 of the metal pipe 70 may be located on the side of the operating area 100 (internal space) that is closer to the longitudinal center of the communication passage 60. This configuration makes it less likely for the metal pipe 70 to shift when inserted, improving the positional accuracy of the metal pipe 70. The other end 702 of the metal pipe 70 may be located outside the communication passage 60.

[0061] As shown in Figure 8, the metal pipe 70 may have an insertion portion 71, an extension portion 72, and a flange portion 73.

[0062] The insertion portion 71 is the part of the metal pipe 70 located inside the communication passage 60. The protruding portion 72 is the part of the metal pipe 70 located outside the communication passage 60. The length L1 of the insertion portion 71 may be shorter than the length L2 of the protruding portion 72. With this configuration, compared to the case where the length L1 of the insertion portion 71 is longer than the length L2 of the protruding portion 72, more heat from the metal pipe 70 can be dissipated to the protruding portion 72, thereby easing the stress on the container 2. In Figure 8, as an example, the length L1 of the insertion portion 71 and the length L2 of the protruding portion 72 are shown with the lower surface of the flange portion 73 as the reference point, but the reference position is not limited to this. For example, the position of the opening 201 may be used as the reference point.

[0063] The flange portion 73 may be located on the protruding portion 72. The flange portion 73 may be joined to the surface of the container 2 where the opening 201 of the communication passage 60 is located, via a brazing material 74 such as silver solder. Having a structure in which the flange portion 73 and the container 2 are joined via a brazing material 74 provides high durability to the connection between the container 2 and the metal pipe 70.

[0064] The brazing material 74 may be located not only between the flange portion 73 and the container 2, but also, for example, between the insertion portion 71 and the connecting passage 60. With this configuration, the connection durability between the container 2 and the metal pipe 70 is high. The brazing material 74 may also be located so as to straddle the surface of the flange portion 73 opposite to the joint surface with the container 2 and the opening surface of the connecting passage 60 in the container 2. That is, the brazing material 74 may be located so as to cover the entire flange portion 73. With this configuration, the connection durability between the container 2 and the metal pipe 70 is high.

[0065] Furthermore, the method of joining the metal pipe 70 and the container 2 is not limited to the method described above. As long as the metal pipe 70 and the container 2 can be joined, the flange portion 73 is not necessarily required.

[0066] Next, we will describe the configuration of the connecting passage 60 and the metal pipe 70 in a cross-sectional view (hereinafter simply referred to as a cross-sectional view) obtained by cutting the connecting passage 60 with a plane perpendicular to the longitudinal direction of the connecting passage 60. Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 8. Also, in Figure 9, the first reinforcing member 40 and the second reinforcing member 50 are omitted.

[0067] As shown in Figure 9, in cross-sectional view, the shape of the connecting passage 60 may be a polygonal shape having multiple corners. As will be described later, the first member 10, the second member 20, and the intermediate member 30 constituting the container 2 are obtained by processing a laminate consisting of multiple layers. Specifically, by processing a laminate consisting of layers 10a and 10b, the first member 10 having a connecting groove 12 is obtained. Similarly, by processing a laminate consisting of layers 20a and 20b, the second member 20 having a connecting groove 22 is obtained. Similarly, by processing a laminate consisting of layers 30a and 30b, the intermediate member 30 having a connecting hole 38 is obtained. In other words, since the connecting passage 60 is composed of multiple layers, it has a polygonal shape with multiple corners.

[0068] Furthermore, as shown in Figure 9, the shape of the metal tube 70 may be circular in cross-sectional view. Therefore, the shapes of the metal tube 70 and the connecting passage 60 may be dissimilar. In addition, the heat dissipation device 1 may have a space between the outer surface of the metal tube 70 and the inner surface of the connecting passage 60.

[0069] The first member 10, the second member 20, and the intermediate member 30 that constitute the connecting passage 60 are made of ceramic. Ceramics generally have a larger Young's modulus than metals, in other words, they have higher rigidity. The metal tube 70, being made of metal, deforms (expands) due to heat in a direction that pushes the connecting passage 60 outward. As a result of this deformation, stress is generated in the connecting passage 60. If there is a space between the outer surface of the metal tube 70 and the inner surface of the connecting passage 60, then even if the metal tube 70 expands, the expansion of the metal tube 70 can be released into this space, compared to a situation where there is no such space. Therefore, because the shapes of the metal tube 70 and the connecting passage 60 are asymmetric in cross-section, the stress on the container 2 due to the deformation of the metal tube 70 caused by temperature changes (especially temperature rises) can be alleviated.

[0070] Furthermore, as shown in Figure 9, in a cross-sectional view, one interior angle in the shape of the connecting passage 60 may be 90° or more, and the sum of all interior angles may be 360° or more. This allows for greater stress on the corners of the connecting passage 60 when the metal pipe 70 expands due to heat, and also reduces the occurrence of cracks in the container 2.

[0071] Furthermore, as shown in Figure 9, the shape of the connecting passage 60 may have different vertical widths W1 and horizontal widths W2. With this configuration, when the metal tube 70 expands due to heat, the expansion force in the short-width direction (Z-axis direction in the example shown in Figure 9) of the connecting passage 60 can be released into the space in the long-width direction (Y-axis direction in the example shown in Figure 9).

[0072] Furthermore, as shown in Figure 9, the metal pipe 70 may be in contact with the passage 60 at multiple points in a cross-sectional view. Although Figure 9 shows an example where the metal pipe 70 is in contact with the passage 60 at two points, the metal pipe 70 may be in contact with the passage 60 at three or more points in a cross-sectional view. With this configuration, the metal pipe 70 can be supported with high precision.

[0073] The cross-sectional shape of the connecting passage 60 is not limited to the example shown in Figure 9. For example, the connecting passage 60 may be square or rectangular in cross-sectional view. Alternatively, the connecting passage 60 may be circular, for example, elliptical, in cross-sectional view, which is not similar to the cross-sectional shape of the metal pipe 70.

[0074] Furthermore, as described above, the heat dissipation device 1 according to the embodiment may be a sealed container made of ceramic. That is, the first member 10, the second member 20, and the intermediate member 30 may be made of ceramic.

[0075] Ceramics generally have a higher Young's modulus compared to metals, meaning they have higher rigidity. A metal tube 70, being made of metal, deforms in a direction that expands the communication passage 60 due to heat. If the heat dissipation device is made of metal, when the metal tube 70 deforms in a direction that expands the communication passage 60, the communication passage 60 is also easily deformed along with this deformation. In contrast, with a ceramic heat dissipation device 1, even if the metal tube 70 deforms in a direction that expands the communication passage 60, the communication passage 60 is less likely to deform compared to a metal heat dissipation device. Therefore, it is easier to ensure airtightness against temperature changes (especially temperature rise) with a ceramic heat dissipation device 1 compared to a metal heat dissipation device.

[0076] From another perspective, ceramics have a smaller coefficient of thermal expansion compared to most metals, with the exception of some metals such as W (tungsten), Mo (molybdenum), Ti (titanium), Nb (niobium), and Zr (zirconium). In other words, the ceramic heat dissipation device 1 is less susceptible to thermal deformation than a metal heat dissipation device. Therefore, the ceramic heat dissipation device 1 maintains the state in which the metal tube 70 presses against the communication passage 60 more easily than a metal heat dissipation device. Consequently, the ceramic heat dissipation device 1 makes it easier to ensure airtightness against thermal cycling compared to a metal heat dissipation device. Furthermore, the ceramic heat dissipation device 1 is less susceptible to corrosion when exposed to acids and high-temperature steam, and is also less susceptible to oxidation at high temperatures compared to a metal heat dissipation device.

[0077] As mentioned above, examples of ceramics that constitute the first member 10, the second member 20, and the intermediate member 30 include alumina, zirconia, and silicon carbide. Of these ceramics, alumina is preferred for use in the first member 10, the second member 20, and the intermediate member 30 because it is inexpensive, environmentally friendly, and has excellent workability.

[0078] In the heat dissipation device 1 according to this embodiment, the interior is under reduced pressure (including vacuum) when no heat source is placed on the upper surface (fifth surface) of the first member 10. On the other hand, when a heat source is placed on the upper surface of the first member 10, the fluid vaporizes and expands in volume, causing the interior of the heat dissipation device 1 to become pressurized. Thus, the pressure state inside the heat dissipation device 1 alternates between a reduced pressure state and a pressurized state depending on the presence or absence of a heat source.

[0079] In contrast, the metal pipe 70 according to this embodiment is pressed toward the communication passage 60, making it easy to ensure both airtightness in a reduced pressure state and airtightness in a pressurized state.

[0080] Next, an example of a method for manufacturing the heat dissipation device 1 according to the embodiment will be described. First, using the raw materials for the first member 10, the second member 20, and the intermediate member 30, green sheets are formed by the doctor blade method or the roll compaction method, and a laminate is obtained by stacking multiple green sheets.

[0081] Next, the obtained laminate is subjected to laser processing or die punching to obtain molded bodies of the first member 10, the second member 20, and the intermediate member 30. For example, by laser processing the laminate, a molded body of the intermediate member 30 can be obtained in which a plurality of steam holes 36, a plurality of reflux holes 37, and a plurality of communication holes 38 are formed. Also, by laser processing the obtained laminate, a molded body of the first member 10 can be obtained in which a plurality of communication grooves 12 and a first groove forming region 110 are formed. Also, by laser processing the obtained laminate, a molded body of the second member 20 can be obtained in which a plurality of communication grooves 22 and a second groove forming region 120 are formed.

[0082] Next, the molded bodies of the first member 10, the second member 20, and the intermediate member 30 are stacked in the order of the second member 20, the intermediate member 30, and the first member 10, and then fired to obtain a sintered body of the container 2 in which the first member 10, the second member 20, and the intermediate member 30 are integrated. In this way, the first member 10, the second member 20, and the intermediate member 30 are integrally molded. Therefore, since no adhesives or the like are required, a highly reliable heat dissipation device 1 can be obtained.

[0083] Furthermore, the method for obtaining the molded bodies of the first member 10, the second member 20, and the intermediate member 30 is not limited to the method described above. For example, the molded bodies may be obtained by processing a green sheet and then laminating the green sheets. Also, in the example described above, the molded bodies of the first member 10, the second member 20, and the intermediate member 30 were individually manufactured and then laminated to obtain the molded body of the container 2. However, the molded body of the container 2 may also be obtained by sequentially laminating processed green sheets.

[0084] Next, the insertion portions 71 of the metal pipe 70 are inserted into each of the multiple connecting passages 60. After that, the flange portion 73 of the metal pipe 70 and the container 2 are joined via brazing material 74.

[0085] Next, for example, fluid is injected into the sintered body from one of the two metal tubes 70. Any gas present inside the sintered body is discharged to the outside through the other metal tube 70 as the fluid is injected.

[0086] Next, a vacuum device such as a vacuum pump is used to create a vacuum inside the sintered body through the communication passage 60. While it is desirable for the inside of the sintered body to be in a vacuum state, it is not strictly required; for example, a reduced-pressure state close to a vacuum is acceptable.

[0087] Next, the communication passage 60 is sealed while the inside of the sintered body is under vacuum. Specifically, as shown in Figure 10, one or more points on the protruding portion 72 (see Figure 8) of the metal tube 70 are pressed together to seal the inside of the container 2. Note that the method of sealing the communication passage 60 is not limited to the above example. For example, the communication passage 60 may be sealed by welding the other end 702 (see Figure 8) of the metal tube 70. Alternatively, the communication passage 60 may be sealed by both pressure welding and welding.

[0088] (First variation) In the embodiment described above, as shown in Figure 8, the length L1 of the insertion portion 71 of the metal tube 70 is shorter than the length L2 of the protruding portion 72, but the configuration is not limited to this. For example, as shown in Figure 11, the length L1 of the insertion portion 71 may be longer than the length L2 of the protruding portion 72. With this configuration, the metal tube 70 is less likely to come off the container 2.

[0089] As described above, the thermal device according to the embodiment (for example, heat dissipation device 1) comprises a ceramic container (for example, container 2), a fluid (for example, fluid), and a metal tube (for example, metal tube 70). The container has an internal space (for example, an operating region 100), an opening connected to the internal space (for example, an opening 201), and a connecting passage (for example, a connecting passage 60) connecting the internal space and the opening. The fluid is located in the internal space. The metal tube is partially inserted into the connecting passage and partially closed off.

[0090] Because the thermal device according to this embodiment has a ceramic container, it has superior durability against temperature changes compared to the metal container described in Patent Document 1. Furthermore, because a portion of the metal tube is located within the communication passage of the thermal device according to this embodiment, even if the metal tube deforms due to temperature changes, the entire container can bear the stress and relieve the stress.

[0091] Furthermore, in the thermal device according to this embodiment, since the communication passage and the metal tube are non-similar, a gap is created between the communication passage and the metal tube, which allows for greater stress relief when the metal tube deforms.

[0092] Therefore, according to the thermal device of this embodiment, durability can be improved.

[0093] The thermal devices described herein are not limited to heat dissipation devices. For example, the thermal devices described herein may be heat storage devices that store latent heat associated with the phase transformation of a heat storage material (an example of a phase-transforming material) as thermal energy. In this case, the heat storage material may be one that undergoes solid-liquid phase transformation or solid-solid phase transformation. Thus, the phase-transforming material does not necessarily have to undergo gas-liquid phase transformation. In other words, the phase-transforming material does not necessarily have to be a liquid; it may be a solid.

[0094] The embodiments disclosed herein should be considered in all respects as 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. [Explanation of symbols]

[0095] 1. Heat dissipation device 2 containers 10 First Member 10a,10b layer 11. First groove 11a First recess 11b First protrusion 12 Communication groove 20 Second Member 20a,20b layer 21 Second trench 21a Second recess 21b Second protrusion 22 Communication groove 30 Intermediate member 30a,30b layer 32 Central part 33 Connection part 36 Steam vents 37 Reflux hole 38 Communication hole 40 First reinforcing member 40a, 40b Reinforcement plates 50 Second reinforcing member 50a, 50b Reinforcement Plates 60 Communication path 70 metal tube 71 Insertion part 72 Protruding part 73 Guard section 74. Wax 100 Operating range 110 First groove forming area 120 Second groove forming area 200 frame area 201 Opening 210 First Slot Area 220 Second Slot Area 230 Third Slot Area 701 one end 702 Other end L1 Length of insertion section L2 Length of the protruding part T1 Working area thickness Thickness of T2 connecting passage W1 Height W2 Width

Claims

1. A ceramic container having an internal space, an opening connected to the internal space, and a passage connecting the internal space and the opening, The fluid located in the aforementioned internal space, A metal tube is partially inserted into the communication passage through the opening and the other part is closed. It has, There are multiple openings, communication passages, and metal pipes. Each of the aforementioned multiple metal tubes is inserted into each of the aforementioned multiple connecting passages. The plurality of openings are thermal devices located on the sides of the container.

2. The thermal device according to claim 1, wherein the plurality of openings are located on the same side surface.

3. When the container is viewed from above, the container has a first region and a second region separated by a straight line including the center of the container, The thermal device according to claim 1, wherein the plurality of openings are located in the first region.

4. Each of the plurality of metal tubes has an insertion portion located within the communication passage and an extension portion located outside the communication passage, The thermal device according to claim 1, wherein in each of the insertion portions, the direction from the end on the internal space side toward the opening side is substantially the same to each other.

5. The thermal device according to claim 1, wherein one end of the metal tube is located within the communication passage.

6. The thermal device according to claim 5, wherein one end of the metal tube is located on the side of the internal space that is closer to the longitudinal center of the communication passage.

7. The thermal device according to claim 1, wherein in a cross-sectional view obtained by cutting the communication passage with a plane perpendicular to the longitudinal direction of the communication passage, the metal tube is in contact with the communication passage at two or more points.

8. The thermal device according to claim 1, wherein the thickness of the internal space is thinner than the thickness of the communication passage.

9. The thermal device according to claim 1, wherein when the container is viewed from above, the internal space is circular.

10. The thermal device according to claim 1, wherein in a cross-sectional view obtained by cutting the communication passage with a plane perpendicular to the longitudinal direction of the communication passage, the shape of the metal tube and the shape of the communication passage are dissimilar.

11. The thermal device according to claim 10, wherein the shape of the communication passage in the cross-sectional view is a polygonal shape having multiple corners.

12. The thermal device according to claim 10, wherein the shape of the metal tube in the cross-sectional view is circular.

13. The thermal device according to claim 10, wherein the shape of the connecting passage in the cross-sectional view has different vertical and horizontal dimensions.

14. The thermal device according to claim 11, wherein in the cross-sectional view, one interior angle in the shape of the communication passage is 90° or more, and the sum of all interior angles is 360° or more.

15. The metal pipe has an insertion portion located within the communication passage and an extension portion located outside the communication passage, The thermal device according to claim 1, wherein the insertion portion is joined to at least a portion of the communication passage.

16. The metal pipe has an insertion portion located within the communication passage, an extension portion located outside the communication passage, and a flange portion located at the extension portion. The thermal device according to claim 1, wherein the flange portion is joined to the surface of the container on which the opening is located.

17. The thermal device according to claim 4, 15, or 16, wherein the length of the insertion portion is shorter than the length of the protruding portion.

18. The thermal device according to claim 1, wherein there is a space between the inner surface of the communication passage and the outer surface of the metal tube.

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