Thermal Devices

Abstract

A thermal device according to the present disclosure utilizes the latent heat of a phase-transforming material. The thermal device according to the present disclosure has a ceramic container and a seal part. The ceramic container includes: a phase-transforming region where the phase-transforming material is enclosed; a frame region that surrounds the phase-transforming region; and a communication path that communicates the phase-transforming region with the outside. The seal part blocks the communication path. The communication path is located in the frame region.

Description

[Technical field]

[0001] The present disclosure relates to thermal devices. [Background technology]

[0002] Thermal devices that utilize the latent heat of a phase-transforming material are known. For example, a vapor chamber, which is one type of thermal device, releases heat from a heat-generating component by transporting heat from a high-temperature part to a low-temperature part using the latent heat associated with the evaporation and condensation of a working fluid sealed inside.

[0003] Patent Document 1 discloses a ceramic vapor chamber having an operating area filled with working fluid, and in which a hole is drilled in part of a ceramic plate constituting the operating area for injecting the working fluid into the operating area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 54-42973 Summary of the Invention

[0005] A thermal device according to one embodiment of the present disclosure is a thermal device that utilizes the latent heat of a phase change material, and includes a ceramic container and a sealing portion. The container includes a phase change region in which a phase change material is sealed, a frame region surrounding the phase change region, and a communication passage that connects the phase change region to the outside. The sealing portion closes the communication passage. The communication passage is located in the frame region. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view of a heat dissipation device according to an embodiment. [Diagram 2] FIG. 2 is a view of the first member according to the embodiment as viewed in the positive direction of the Z axis from the negative direction of the Z axis. [Diagram 3]FIG. 3 is a view of the second member according to the embodiment as viewed in the negative direction of the Z axis from the positive direction of the Z axis. [Figure 4] FIG. 4 is a view of the intermediate member according to the embodiment, viewed from the Z-axis positive side toward the Z-axis negative side. [Diagram 5] 5 is a diagram in which the first groove formation region shown in FIG. 2 and the second groove formation region shown in FIG. 3 are superimposed on the intermediate member shown in FIG. [Figure 6] FIG. 6 is a diagram for explaining the flow of the working fluid in the heat dissipation device according to the embodiment. [Figure 7] FIG. 7 is a diagram for explaining the flow of the working fluid in the heat dissipation device according to the embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view showing an example of the configuration of the communication passage. [Figure 9] FIG. 9 is a schematic cross-sectional view showing another example of the configuration of the communication passage. [Figure 10] FIG. 10 is a schematic cross-sectional view showing another example of the configuration of the communication passage. [Figure 11] FIG. 11 is a schematic cross-sectional view showing another example of the configuration of the communication passage. [Figure 12] FIG. 12 is a schematic perspective view showing another configuration example of the second portion of the communication passage. [Figure 13] FIG. 13 is a schematic plan view showing another configuration example of the individual passages. [Figure 14] FIG. 14 is a schematic plan view showing another configuration example of the individual passages. [Figure 15] FIG. 15 is a schematic plan view showing another configuration example of the individual passages. [Figure 16] FIG. 16 is a schematic plan view showing another configuration example of the individual passages. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a form for carrying out a thermal device according to the present disclosure (hereinafter, referred to as an "embodiment") will be described in detail with reference to the drawings. Note that the present disclosure is not limited to this embodiment. In addition, each embodiment can be appropriately combined within a range that does not cause a contradiction in the processing contents. In addition, the same parts in each of the following embodiments are given the same reference numerals, and duplicated explanations will be omitted.

[0008] In addition, in the embodiments described below, expressions such as "constant", "orthogonal", "vertical" and "parallel" may be used, but these expressions do not necessarily mean "constant", "orthogonal", "vertical" and "parallel" strictly. In other words, each of the above expressions allows for deviations due to, for example, manufacturing accuracy and installation accuracy.

[0009] In addition, in order to make the explanation easier to understand, each of the drawings referred to below may show an orthogonal coordinate system that defines an X-axis direction, a Y-axis direction, and a Z-axis direction that are perpendicular to each other, and has the positive Z-axis direction as the vertically upward direction.

[0010] In the following, as an example of a thermal device according to the present disclosure, a heat dissipation device, specifically a vapor chamber, 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 working fluid (an example of a phase-changing substance) will be described.

[0011] First, the overall configuration of a heat dissipation device according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a perspective view of a heat dissipation device according to an embodiment.

[0012] 1, the heat dissipation device 1 has a ceramic container 2. The container 2 has 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 are all plate-shaped, and are stacked so that the first member 10 and the second member 20 sandwich the intermediate member 30.

[0013] The container 2 has an operating region 100 and a frame region 200. The operating region 100 has an internal space, and a working liquid as a phase-changing substance is sealed in the internal space. As the working liquid, for example, water, a hydrocarbon compound, an organic liquid (e.g., ethanol, methanol, etc.), ammonia, or other liquids can be used.

[0014] The frame region 200 is a region surrounding the active region 100. In other words, the frame region 200 is a region of the heat dissipation device 1 that is outside the active region 100. The active region 100 is generally hollow, whereas the frame region 200 is generally solid.

[0015] The frame region 200 is a region that is intentionally formed wide to prevent, for example, working fluid or working fluid vapor from leaking from 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 prevent the outside atmosphere from entering the internal space of the operating region 100 from the above interfaces (i.e., to ensure airtightness).

[0016] The container 2 has a plurality of (here, two) communication passages 14, 15 that communicate the internal space of the operating region 100 with the outside. Of the communication passages 14, 15, for example, the communication passage 14 is used as a working fluid injection hole, and the communication passage 15 is used as a gas discharge hole. In this case, in the manufacturing process of the heat dissipation device 1, the working fluid is injected into the internal space of the operating region 100 from the communication passage 14, and accordingly, the gas present in the internal space of the operating region 100 is discharged to the outside through the communication passage 15. The communication passage 14 is located near one of the four corners of the first member 10, and the communication passage 15 is located near a corner diagonally opposite the communication passage 14.

[0017] It is not essential that the heat dissipation device 1 has a plurality of communication paths 14, 15. For example, the heat dissipation device 1 may have only one of the communication paths 14, 15.

[0018] The communication passages 14 and 15 are closed by a sealing portion 5. For example, a resin member, a metal member, a glass member, a ceramic member, or the like can be used as the sealing portion 5. The sealing portion 5 may be flush with the upper surface of the first member 10, or may protrude from the upper surface of the first member 10. As described below, a helical insert may be used for part of the sealing portion 5. By closing the communication passages 14 and 15 by the sealing portion 5, the internal space of the heat dissipation device 1 is sealed and the working fluid is sealed in the working region 100. In this way, the heat dissipation device 1 is a sealed container with a sealed interior.

[0019] The working fluid is filled at a ratio of, for example, 10% by volume or more and 95% by volume or less with respect to the total volume of the internal space of the operating region 100. Preferably, the ratio is 30% by volume or more and 75% by volume or less. More preferably, the ratio is 40% by volume or more and 65% by volume or less. The remaining part of the internal space of the operating region 100 other than the working fluid is in a vacuum state containing a part of the vaporized working fluid. This makes it possible to maintain gas-liquid equilibrium even in a high-temperature environment, making it difficult to dry out, and also allows efficient thermal diffusion even in a low-temperature environment, making it possible to increase thermal diffusivity in various temperature ranges.

[0020] The first member 10, the second member 20, and the intermediate member 30 are made of ceramic. Examples of the ceramic that constitutes the first member 10, the second member 20, and the intermediate member 30 include alumina (Al 2 O 3 ), zirconia (ZrO 2 ), silicon carbide (SiC), silicon nitride (Si 3 N 4 ), Aluminum Nitride (AlN), Cordierite (Mg 2 Al 3 (AlSi 5 O 18 )), silicon-impregnated silicon carbide (SiSiC), etc. Also, the ceramics constituting the first member 10, the second member 20, and the intermediate member 30 may be single crystal bodies.

[0021] Metallic heat dissipation devices are difficult to obtain rigidity due to the material and manufacturing method, and are difficult to thin. In addition, since the parts of metallic heat dissipation devices that come into contact with the working fluid are made of metal, there is room for improvement in terms of corrosion resistance. In contrast, the heat dissipation device 1 according to the embodiment is made of a first member 10, a second member 20, and an intermediate member 30 that are all made of ceramic, so that it is easier to thin the device compared to metallic heat dissipation devices and has excellent corrosion resistance.

[0022] 1, the heat dissipation device 1 is installed in a position in which the first member 10 faces upward, but the position of the heat dissipation device 1 is not limited to the example of FIG 1. For example, the heat dissipation device 1 may be installed in a position in which the first member 10 faces downward. Moreover, the heat dissipation device 1 may be installed vertically instead of horizontally as shown in FIG 1.

[0023] Since ceramics are a brittle material, an important issue for a heat dissipation device having a ceramic container is how to ensure durability against stresses generated by, for example, phase transformation of the working fluid.

[0024] Here, the vapor chamber described in Patent Document 1 has a communication passage in the operating area for injecting the working fluid. The thickness of the ceramic in the operating area is reduced by the amount of the internal space. For this reason, the vapor chamber described in Patent Document 1, in which the communication passage is provided in the operating area, is prone to lacking durability against stress, and there is a risk of cracks or the like occurring in the container. Furthermore, cracks occurring in the container may cause the working fluid sealed in the internal space to dry out, resulting in a deterioration in heat dissipation efficiency.

[0025] In contrast, in the heat dissipation device 1 according to the embodiment, the communication paths 14, 15 are located in the frame region 200. The frame region 200 is solid, unlike the operating region 100. By having the communication paths 14, 15 located in the frame region 200, durability can be improved compared to a case in which the communication paths 14, 15 are located in the operating region 100. In this way, the heat dissipation device 1 according to the embodiment can improve durability.

[0026] Furthermore, according to the heat dissipation device 1 of the embodiment, a larger effective space can be secured in the operating area 100 compared to when the communicating passages 14, 15 are located in the operating area 100, thereby improving the heat dissipation characteristics.

[0027] Moreover, since the frame region 200 in which the communication paths 14, 15 are located is made of the same ceramic material as the operating region 100, stress due to a difference in thermal expansion is unlikely to occur. Therefore, the heat dissipation device 1 according to the embodiment has high reliability.

[0028] Next, the configuration of the first member 10 will be described with reference to Fig. 2. Fig. 2 is a diagram of the first member 10 according to the embodiment, viewed in the positive direction of the Z axis from the negative direction of the Z axis.

[0029] Fig. 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 Fig. 2, the first member 10 has a lattice-shaped first groove portion 11 on the third surface.

[0030] The first groove portion 11 has a first recess 11a recessed into 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 has a rectangular outline in plan view. The first protrusions 11b are arranged in the vertical and horizontal directions at intervals within the first recess 11a. The first recess 11a and the first protrusions 11b form a lattice shape in the first groove portion 11.

[0031] Hereinafter, the area of ​​the third surface of the first member 10 where the first groove portion 11 is located will be referred to as the "first groove forming area 110." The first groove forming area 110 constitutes a part of the operating area 100. The first member 10 also has a rectangular frame-shaped first frame area 210 that surrounds the first groove forming area 110. The first frame area 210 constitutes a part of the frame area 200.

[0032] A plurality of (here, two) through holes 141a, 151a penetrating the first member 10 in the thickness direction (here, the Z-axis direction) are positioned in the first frame region 210. The through hole 141a constitutes a part of the first portion 141 of the communication passage 14, and the through hole 151a constitutes a part of the first portion 151 of the communication passage 15.

[0033] A heat source is disposed in the center of the upper surface (fifth surface) of the first member 10, which is located opposite the lower surface (third surface).

[0034] Next, the configuration of the second member 20 will be described with reference to Fig. 3. Fig. 3 is a diagram of the second member 20 according to the embodiment, viewed in the negative Z-axis direction from the positive Z-axis direction side.

[0035] Fig. 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 Fig. 3, the second member 20 has a lattice-shaped second groove portion 21 on the fourth surface.

[0036] The second groove portion 21 has a second recess 21a recessed relative to the fourth surface and a plurality of second protrusions 21b located within the second recess 21a. The second recess 21a is located in the center of the fourth surface, and has a rectangular outline in plan view. The plurality of second protrusions 21b are arranged in the vertical and horizontal directions at intervals within the second recess 21a. The second recess 21a and the plurality of second protrusions 21b form the second groove portion 21 in a lattice shape.

[0037] Hereinafter, the region of the fourth surface of the second member 20 where the second groove portion 21 is located will be referred to as the "second groove formation region 120." The second groove formation region 120 constitutes a part of the operating region 100. In addition, the second member 20 has a second frame region 220 in the shape of a rectangular frame that surrounds the second groove formation region 120. The second frame region 220 constitutes a part of the frame region 200.

[0038] The size of the second groove formation region 120 in the second member 20 is the same as the size of the first groove formation region 110 in the first member 10. In addition, the position of the second groove formation region 120 on the fourth surface of the second member 20 is the same as the position of the first groove formation region 110 on the third surface of the first member 10.

[0039] In this manner, by forming the first groove portion 11 and the second groove portion 21 in a lattice shape, it is possible to efficiently circulate the working fluid in the internal space of the heat dissipation device 1. Note that the first groove portion 11 and the second groove portion 21 do not necessarily need to be lattice-shaped.

[0040] In the second frame region 220, there are positioned a plurality of (here, two) recesses 141b, 151b recessed relative to the upper surface (fourth surface) of the second member 20. The recesses 141b form a part of the first portion 141 of the communication passage 14, and the recesses 151b form a part of the first portion 151 of the communication passage 15.

[0041] Further, grooves 142b and 152b are located in the second frame region 220. Groove 142b is a passage extending in a second direction (here, the Y-axis direction) intersecting with the extension direction (first direction, here the Z-axis direction) of first portion 141 of communication passage 14, with one end opening into recess 141b in first portion 141 and the other end opening into second groove-forming region 120. Groove 152b is a passage extending in a second direction (here, the Y-axis direction) intersecting with the extension direction (first direction, here the Z-axis direction) of first portion 151 of communication passage 15, with one end opening into recess 151b in first portion 151 and the other end opening into second groove-forming region 120.

[0042] Next, the configuration of the intermediate member 30 will be described with reference to Fig. 4. Fig. 4 is a diagram of the intermediate member 30 according to the embodiment, viewed in the Z-axis negative direction from the Z-axis positive direction side.

[0043] As shown in Fig. 4, the intermediate member 30 has a third frame region 230 having a rectangular frame shape. The third frame region 230 constitutes a part of the frame region 200. The intermediate member 30 also has a central portion 32 that is circular in plan view and 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 Fig. 4, the central portion 32 is located at the center of the intermediate member 30. The multiple connecting portions 33 extend radially from the central portion 32 toward the third frame region 230 at intervals from one another while increasing in width.

[0044] The intermediate member 30 further has 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 each penetrate the upper surface (first surface) and the lower surface (second surface) of the intermediate member 30.

[0045] The multiple steam holes 36 function as part of a flow path for vapor of the working fluid. The multiple steam holes 36 are located between two adjacent connection parts 33. That is, the multiple steam holes 36 and the multiple connection parts 33 are located alternately in the circumferential direction. Like the multiple connection parts 33, the multiple steam holes 36 are spaced apart from one another and extend radially from the central part 32 toward the third frame region 230 while increasing in width.

[0046] The multiple reflux holes 37 function as part of a flow path for the working fluid. The reflux holes 37 are fine holes having a smaller opening area than the above-mentioned steam holes 36. Specifically, the reflux holes 37 are small enough to generate capillary action in the working fluid passing through the reflux holes 37.

[0047] A plurality of (here, two) through holes 141c, 151c penetrating the intermediate member 30 in the thickness direction (here, the Z-axis direction) are positioned in the third frame region 230. The through hole 141c constitutes a part of the first portion 141 of the communication passage 14, and the through hole 151c constitutes a part of the first portion 151 of the communication passage 15.

[0048] Fig. 5 is a diagram in which the first groove forming region 110 shown in Fig. 2 and the second groove forming region 120 shown in Fig. 3 are superimposed on the intermediate member 30 shown in Fig. 4. Note that, in Fig. 5, the communication passages 14 and 15 are omitted for ease of understanding.

[0049] 5, the first groove formation region 110 and the second groove formation region 120 overlap with the third frame region 230 of the intermediate member 30. In other words, the first groove formation region 110 and the second groove formation region 120 extend outward from a region in the intermediate member 30 where the multiple steam holes 36 and the multiple reflux holes 37 are formed (hereinafter referred to as the "hole formation region").

[0050] In this way, by making the first groove formation region 110 of the first member 10 and the second groove formation region 120 of the second member 20 wider than the hole formation region of the intermediate member 30, the internal space of the heat dissipation device 1 can be expanded outward compared to when the first groove formation region 110 and the second groove formation region 120 are made approximately the same as the hole formation region.

[0051] The heat source is disposed in the center of the heat dissipation device 1. Therefore, the temperature of the heat dissipation device 1 decreases the farther it is from the heat source, i.e., the closer it is to the outer periphery of the heat dissipation device 1. Also, the vapor of the working fluid condenses into liquid as it moves to the low-temperature region. Therefore, by expanding the internal space of the heat dissipation device 1 outward, condensation of the working fluid occurs more easily. This makes it possible to make it difficult for dry-out to occur.

[0052] Note that, while an example has been shown here in which the first groove formation region 110 and the second groove formation region 120 extend outward from the hole formation region of the intermediate member 30, this is not limiting, and the hole formation region of the intermediate member 30 may extend outward from the first groove formation region 110 and the second groove formation region 120.

[0053] The operating region 100 of the heat dissipation device 1 has an internal space sandwiched between a first groove forming region 110 and a second groove forming region 120, and a working fluid is sealed in the internal space. In addition, an intermediate member 30 is interposed between the first groove forming region 110 and the second groove forming region 120 in the internal space, and thus the operating region 100 is partitioned 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. The first space and the second space are connected by a steam hole 36 and a reflux hole 37 formed in the intermediate member 30.

[0054] Next, the flow of the working fluid in the heat dissipation device 1 according to the embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 and Fig. 7 are diagrams for explaining the flow of the working fluid in the heat dissipation device 1 according to the embodiment. Note that Fig. 6 is a diagram in which the third frame region 230 is omitted from the diagram shown in Fig. 5, and Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. In Fig. 6 and Fig. 7, the flow of steam is indicated by open arrows, and the flow of liquid is indicated by filled arrows.

[0055] The working fluid is heated by the heat source and vaporized into steam. As described above, the heat source is disposed in the center of the upper surface (fifth surface) of the first member 10 (see Figs. 1 and 2). Therefore, the vapor of the working fluid is generated in the center of the first space (the space sandwiched between the first member 10 and the intermediate member 30).

[0056] The vapor of the working fluid passes through the first groove portion 11 of the first groove formation region 110, diffuses in the in-plane direction (XY plane direction) of the heat dissipation device 1 (see the open arrows in Figure 6), and moves through the multiple steam holes 36 to the second space (the space sandwiched between the second member 20 and the intermediate member 30) (see the open arrows in Figure 7).

[0057] The vapor that has moved to the second space is condensed and liquefied due to a drop in temperature. The liquefied working fluid moves through the second groove formation region 120 toward the center of the heat dissipation device 1 due to the capillary force of the second groove portion 21 (see the black arrow in FIG. 6). During this process, the working fluid enters the return hole 37 and is returned to the first space by the capillary force of the return hole 37 (see the black arrow in FIG. 7). By repeating the above cycle, the heat dissipation device 1 can transfer heat from the heat source.

[0058] Next, the configuration of the communication passages 14 and 15 will be described with reference to Fig. 8. Fig. 8 is a schematic cross-sectional view showing an example of the configuration of the communication passage 14. Although Fig. 8 shows the communication passage 14 as an example, the communication passage 15 has a similar configuration to the communication passage 14.

[0059] 8, the communication passage 14 connects the internal space of the operating region 100 with the outside. The communication passage 14 has a first portion 141 that extends in the thickness direction of the container 2 (here, the Z-axis direction) and opens to the outside, and a second portion 142 that extends in the surface direction of the container 2 (here, the Y-axis direction) and opens to the internal space of the operating region 100.

[0060] The first portion 141 is formed by the through hole 141a of the first member 10, the recess 141b of the second member 20, and the through hole 141c of the intermediate member 30. The second portion 142 is formed by the groove portion 142b of the second member 20 and the lower surface 302 (second surface) of the intermediate member 30. Note that, although an example in which the recess 141b of the communication passage 14 is recessed further than the groove portion 142b of the second portion 142 is shown in FIG. 8, the recess 141b and the groove portion 142b may be flush with each other.

[0061] Thus, the communication path 14 has a first portion 141 extending in a first direction (here, the Z-axis direction) and a second portion 142 extending in a direction intersecting the first direction (here, the Y-axis direction). In other words, the communication path 14 is bent. Therefore, according to the heat dissipation device 1 according to the embodiment, even if high pressure occurs in the operating region 100, high pressure is unlikely to be applied to the sealing portion 5, and therefore reliability is high.

[0062] In a cross-sectional view (i.e., the cross-sectional view shown in FIG. 8 ) when the communicating passage 14 is cut along the thickness direction (here, the Z-axis direction) of the container 2, the passage width (width along the Y-axis direction) of the first portion 141 is D1, and the passage width (width along the Z-axis direction) of the second portion 142 is D2. In this case, the passage width D2 of the second portion 142 is smaller than the passage width D1 of the first portion 141. In other words, the passage cross-sectional area of ​​the second portion 142 is smaller than the passage cross-sectional area of ​​the first portion 141.

[0063] This configuration can prevent the working fluid from entering the communication passage 14 from the operating region 100. This prevents the amount of working fluid in the operating region 100 from decreasing, thereby preventing a deterioration in heat dissipation characteristics. In addition, since the first portion 141 has a large cross-sectional area of ​​the passage, it is easy to inject the working fluid in the manufacturing process of the heat dissipation device 1.

[0064] The first portion 141 is open on the upper surface of the first member 10 and extends across the first and second spaces of the operating region 100 in the frame region 200. The second portion 142 is located on the second space side of the operating region 100 in the frame region 200.

[0065] In the heat dissipation device 1, the first space side of the first and second spaces is under high pressure. In other words, the second space side of the first and second spaces is under relatively low pressure. Therefore, by positioning the second portion 142 on the second space side, it is possible to prevent high pressure from being applied to the communication passage 14.

[0066] 1, the communication passage 14 is positioned so as to sandwich the operating region 100 between itself and the communication passage 15. By arranging the two communication passages 14, 15 in this manner, it is possible to prevent a local decrease in durability compared to, for example, a case in which the two communication passages 14, 15 are arranged side by side.

[0067] 9 to 11 are schematic cross-sectional views showing other configuration examples of the communication passage 14. In order to facilitate understanding, the sealing portion 5 is omitted in Fig. 11.

[0068] 9, the second portion 142 may have a protruding portion 41 that protrudes from the bottom surface of the groove portion 142b, i.e., the upper surface (fourth surface) of the second member 20, toward the lower surface (second surface) of the intermediate member 30. In addition, the second portion 142 may have a protruding portion 42 that protrudes from the lower surface 302 (second surface) of the intermediate member 30 toward the bottom surface of the groove portion 142b.

[0069] In this way, when the protrusions 41, 42 are located in the second portion 142, the passage width D2 (see FIG. 8) of the second portion 142 is partially narrowed. This makes it possible to prevent the working fluid located in the second space of the operating region 100 from infiltrating into the communicating passage 14. In addition, by providing the protrusion 41 protruding from the bottom of the groove 142b and the protrusion 42 protruding from the lower surface (second surface) of the intermediate member 30 in the second portion 142 to form the second portion 142 into a labyrinth, it is possible to further prevent the working fluid from infiltrating into the communicating passage 14.

[0070] 9 shows an example in which the protrusion 41 is located at the end of the second portion 142 that faces the operating region 100, and the protrusion 42 is located at the end of the second portion 142 that faces the first portion 141. However, the present invention is not limited to this, and the protrusion 41 may be located at the end of the second portion 142 that faces the first portion 141, and the protrusion 42 may be located at the end of the second portion 142 that faces the operating region 100.

[0071] 10, the first portion 141 may have a tapered shape in which the passage width gradually narrows from the opening to the outside toward the depth direction of the container 2. In other words, the first portion 141 has a passage cross-sectional area at the connection end with the second portion 142 that is larger than the passage cross-sectional area at the opening end that opens to the outside. SmallIn this manner, by narrowing the first portion 141 on the second portion 142 side, it is possible to further suppress the intrusion of the working fluid from the operating area 100 into the communication passage 14. Even if the working fluid intrudes into the communication passage 14, 、 By narrowing the first portion 141, the working fluid that has entered the communication passage 14 can be easily returned to the working area 100 by capillary force.

[0072] As shown in FIG. 11, the opening end opening to the outside may have a step portion 43 expanding radially outward of the first portion 141. Providing the step portion 43 makes the space inside the communication passage 14 wider, so that the pressure acting on the communication passage 14 can be alleviated. Providing the step portion 43 also makes it possible to increase the contact area with the sealing portion 5, so that the sealing ability of the operating region 100 can be improved. Providing the step portion 43 also makes it easier to use, for example, a helical insert as the sealing portion 5. When a helical insert is used as the sealing portion 5, for example, it is easy to connect the heat dissipation device 1 to another member.

[0073] Fig. 12 is a schematic perspective view showing another configuration example of the second portion 142 in the communication passage 14. Specifically, Fig. 12 shows an enlarged view of the periphery of the second portion 142 on the upper surface (fourth surface) of the second member 20.

[0074] 12, the second portion 142 has a plurality of (here, five) individual passages 142a-142e. The individual passages 142a-142e each connect the first portion 141 and the operating region 100. That is, one end of each of the individual passages 142a-142e opens into the recess 141b of the first portion 141 and the other end opens into the second groove forming region 120.

[0075] The cross-sectional area of ​​each of the individual passages 142a to 142e is smaller than the cross-sectional area of ​​the first portion 141. As an example, the width of each of the individual passages 142a to 142e is not less than 150 μm and not more than 400 μm, and the height is not less than 100 μm and not more than 1000 μm.

[0076] In this way, the second portion 142 of the communication passage 14 is divided into a plurality of individual passages 142a-142e each having a small passage cross-sectional area. With this configuration, capillary force works more easily compared to when the second portion 142 is configured as a single passage. This allows the working fluid to be injected more smoothly into the operating region 100 during the manufacturing process of the heat dissipation device 1, for example. In addition, when the heat dissipation device 1 is in use, it is possible to prevent high pressure in the operating region 100 from being applied to the communication passage 14 and the sealing portion 5.

[0077] Each of the individual passages 142a-142e extends linearly from the first portion 141 toward the operating region 100. In this case, the second convex portion 21b of the second groove portion 21 is not located on an extension line of each of the individual passages 142a-142e. In other words, each of the individual passages 142a-142e is provided at a position where it passes between two adjacent second convex portions 21b when each of the individual passages 142a-142e is extended toward the operating region 100. By providing the individual passages 142a-142e at such a position, the flow of the working fluid from the communication passage 14 to the operating region 100 is less likely to be obstructed by the second convex portions 21b.

[0078] In addition, Figure 1 2 Although an example is shown in which the second convex portion 21b is not located on any of the extension lines of the individual passages 142a to 142e, it is sufficient that the second convex portion 21b is not located on the extension line of at least one of the individual passages 142a to 142e.

[0079] 13 to 16 are schematic plan views showing other configuration examples of the individual passages 142a to 142e.

[0080] As shown in FIG. 13, the individual passages 142a to 142e are formed on the upper surface (the first surface) of the second member 20. 4 The individual passages 142a to 142e may extend in the second direction (Y direction) while meandering within the plane (XY plane) of the first region 100. With this configuration, the flow path resistance of the individual passages 142a to 142e can be increased. Therefore, the infiltration of the working fluid in the working region 100 into the communication passage 14 can be further suppressed.

[0081] 14, the individual passages 142a-142e may be closer to each other from the first portion 141 toward the operating region 100. Alternatively, as shown in FIG 15, the individual passages 142a-142e may be farther apart from each other from the first portion 141 toward the operating region 100.

[0082] In this way, the individual passages 142a-142e do not necessarily need to extend in the same direction. By making the individual passages 142a-142e extend in different directions, it is possible to obtain the communication passage 14 in which the flow direction of the working fluid is adjusted so that the working fluid flowing from each of the individual passages 142a-142e into the operating region 100 does not collide with the second protrusion 21b located within the operating region 100 as much as possible.

[0083] 16, the individual passages 142a-142e may have a tapered shape in which the passage cross-sectional area decreases from the first portion 141 toward the actuation region 100. With this configuration, the capillary force gradually increases from the first portion 141 toward the actuation region 100, making it easier for the working fluid to flow from the first portion 141 into the actuation region 100. In other words, the intrusion of the working fluid from the actuation region 100 into the communication passage 14 can be further suppressed.

[0084] Next, an example of a manufacturing method of the heat dissipation device 1 according to the embodiment will be described. First, green sheets are formed by a doctor blade method, a roll compaction method, or the like using raw materials of the first member 10, the second member 20, and the intermediate member 30, and a laminate is obtained by stacking a plurality of green sheets.

[0085] Next, the obtained laminate is subjected to laser processing or die punching to obtain each of the molded bodies of the first member 10, the second member 20, and the intermediate member 30. For example, by performing laser processing on the laminate, a molded body of the intermediate member 30 in which the through holes 141c, 151c, the plurality of steam holes 36, and the plurality of reflux holes 37 are formed can be obtained. In addition, by performing laser processing on the obtained laminate, a molded body of the first member 10 in which the through holes 141a, 151a and the first groove formation region 110 are formed can be obtained. In addition, by performing laser processing on the obtained laminate, a molded body of the second member 20 in which the recesses 141b, 151b, the grooves 142b, 152b, and the second groove formation region 120 are formed can be obtained.

[0086] Next, the respective compacts 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 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 manner, the first member 10, the second member 20 and the intermediate member 30 are integrally formed. Therefore, since no adhesive or the like is required, a highly reliable heat dissipation device 1 can be obtained.

[0087] The method for obtaining each of the molded bodies of the first member 10, the second member 20, and the intermediate member 30 is not limited to the above-mentioned method, and may be, for example, a method in which each of the molded bodies is obtained by processing green sheets and then laminating the green sheets. In the above-mentioned example, the molded body of the container 2 is obtained by producing each of the molded bodies of the first member 10, the second member 20, and the intermediate member 30 individually and then laminating them, but the molded body of the container 2 may be obtained by, for example, sequentially laminating processed green sheets.

[0088] Next, the working fluid is injected into the sintered body, for example, from one of the communication passages 14, 15. The gas present inside the sintered body is discharged to the outside from the other of the communication passages 14, 15 as the working fluid is injected.

[0089] Next, a vacuum pump or other decompression device is used to evacuate the inside of the sintered body through the communicating passages 14, 15. Note that while it is desirable for the inside of the sintered body to be in a vacuum state, it is not necessary for the inside of the sintered body to be in a strict vacuum state, and for example, a reduced pressure state close to a vacuum state may be acceptable. Next, while the inside of the sintered body is in a vacuum state, the communicating passages 14, 15 are sealed. As a result, the communicating passages 14, 15 are sealed by the sealing portion 5, and the heat dissipation device 1 is obtained.

[0090] As described above, the thermal device according to the embodiment (for example, the heat dissipation device 1) is a thermal device that utilizes the latent heat of a phase change material (for example, a working fluid), and has a ceramic container (for example, the container 2) and a sealing portion (for example, the sealing portion 5). The container has a phase change region (for example, the operating region 100) in which the phase change material is sealed, a frame region (for example, the frame region 200) surrounding the phase change region, and communication passages (for example, the communication passages 14, 15) that connect the phase change region to the outside. The sealing portion blocks the communication passages. The communication passages are located in the frame region.

[0091] Therefore, the thermal device according to the embodiment can improve durability.

[0092] The thermal device according to the present disclosure is not limited to a heat dissipation device. For example, the thermal device according to the present disclosure may be a heat storage device that stores latent heat accompanying a phase transformation of a heat storage material (one example of a phase change material) as thermal energy. In this case, the heat storage material used may be one that undergoes a solid-liquid phase transformation or a solid-solid phase transformation. In this way, the phase change material does not necessarily have to undergo a gas-liquid phase transformation. In other words, the phase change material does not necessarily have to be a liquid, and may be a solid.

[0093] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0094] 1. Heat dissipation devices 5 Sealing part 10 First member 11 First groove 11a First recess 11b First protrusion 14,15 Communication path 20 Second member 21 Second groove 21a Second recess 21b Second protrusion 30 Intermediate parts 36 Steam Vent 37 Reflux hole 100 Operating Range 141 Part 1 141a Through hole 141b Recess 141c through hole 142 Part 2 142a Individual aisle 200 frame area

Claims

1. A thermal device utilizing latent heat of a phase change material, a ceramic container having a phase change region in which the phase change material is sealed, a frame region surrounding the phase change region, and a communication passage located in the frame region and connecting the phase change region to the outside; a sealing portion that closes the communication passage; having The communication passage is A first portion extending in a first direction and opening to the outside; a second portion extending in a second direction intersecting the first direction and opening into the phase transformation region; having The second portion has a plurality of individual passages each having a cross-sectional area smaller than a cross-sectional area of ​​the passages of the first portion.

2. The thermal device of claim 1 , wherein a passage cross-sectional area of ​​the second portion is smaller than a passage cross-sectional area of ​​the first portion.

3. The thermal device according to claim 1 , wherein the individual passages extend in the second direction in a serpentine manner.

4. The thermal device according to claim 1 , wherein the individual passages approach each other from the first portion toward the phase transformation region.

5. The thermal device according to claim 1 , wherein the individual passages are spaced apart from each other from the first portion toward the phase change region.

6. 6. The thermal device according to claim 1, wherein the individual passages have a passage cross-sectional area that decreases from the first portion toward the phase transformation region.

7. The container comprises: a flat intermediate member having a first surface and a second surface opposite to the first surface, the flat intermediate member having a plurality of reflux holes penetrating the first surface and the second surface; a first member having a first groove portion on a third surface facing the first surface of the intermediate member, and a heat source being disposed on a fifth surface located on the opposite side to the third surface; a second member having a second groove portion on a fourth surface opposite to the second surface of the intermediate member; having 7. The thermal device according to claim 1, wherein a working fluid as the phase change material is located in the phase change region sandwiched between the first groove portion and the second groove portion.

8. The phase transformation region is a first space defined by the first surface of the intermediate member and the third surface of the first member; a second space defined by the second surface of the intermediate member and the fourth surface of the second member; having the first portion extends across the first space and the second space in the frame region when the container is viewed in cross section, The thermal device according to claim 7 , wherein the second portion is located on the second space side of the first space and the second space in the frame region when the container is viewed in cross section.

9. The thermal device according to claim 8 , wherein the second portion has a protrusion that protrudes toward the second surface from a surface opposite the second surface.

10. 10. The thermal device according to claim 6, wherein the first portion has a passage cross-sectional area at a connection end with the second portion that is smaller than a passage cross-sectional area at an opening end that opens to the outside.

11. The thermal device according to claim 6, wherein the first portion has a step at an end portion that opens to the outside.

12. At least two of the communication passages are provided, 12. The thermal device according to claim 6, wherein one of the communication paths is positioned so as to sandwich the phase change region between itself and another of the communication paths.

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