heat dissipating member

Abstract

The heat dissipating member (1, 1A to 1G) of the present application has an intermediate member (30, 30A, 30B) composed of ceramic and flat plate shape, a first member (10, 10F), and a second member (20). The intermediate member (30, 30A, 30B) has a plurality of through holes (37) penetrating a first face (301) and a second face (302) located on opposite sides of each other. The first member (10, 10F) has a first groove portion (11) on a third face opposed to the first face (301) of the intermediate member (30, 30A, 30B). The second member (20) has a plurality of second groove portions (21) on a fourth face opposed to the second face (302) of the intermediate member (30, 30A, 30B), and a heat source is disposed on a fifth face located on the opposite side of the fourth face.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a heat dissipating member. BACKGROUND

[0002] In the past, a heat dissipating member (heat pipe) that utilizes a cycle of evaporation and condensation of a working fluid to efficiently move heat from a high temperature portion to a low temperature portion is known.

[0003] In Patent Literature 1, a heat pipe made of metal in which a flat plate-shaped intermediate member is interposed between a flat plate-shaped upper member and a flat plate-shaped lower member is disclosed. A lattice-shaped groove is formed on the lower surface of the upper member and the upper surface of the lower member, respectively. In addition, a plurality of vapor holes extending in a radial direction and a plurality of fine through holes that generate a capillary force are formed in the intermediate member.

[0004] In the heat pipe described in Patent Literature 1, the vapor holes communicate with each of the recesses of the upper member and the lower member, thereby forming a vapor diffusion flow path that diffuses the vapor of the working fluid in the planar direction. In addition, the through holes communicate with each of the recesses of the upper member and the lower member, thereby forming a fine capillary flow path that returns the working fluid in a vertical direction orthogonal to the planar direction.

[0005] In addition, in Patent Literature 2, a heat pipe composed of ceramic is disclosed.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent No. 4112602

[0009] Patent Literature 2: Japanese Patent Application Laid-Open No. 59-173690 SUMMARY

[0010] SOLUTION TO THE PROBLEM

[0011] A heat dissipating member of one aspect of the present disclosure has an intermediate member composed of ceramic and flat plate-shaped, a first member, and a second member. The intermediate member has a plurality of through holes that penetrate a first surface and a second surface located on opposite sides of each other. The first member has a first groove portion on a third surface that opposes the first surface of the intermediate member. The second member has a plurality of second groove portions on a fourth surface that opposes the second surface of the intermediate member, and a heat source is disposed on a fifth surface located on the opposite side of the fourth surface. In addition, the through holes are reduced in diameter from the first surface side toward the second surface side. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a perspective view of the heat dissipating member of the embodiment.

[0013] Figure 2 is a view of the first member of the embodiment as viewed from the negative direction of the Z axis toward the positive direction of the Z axis.

[0014] Figure 3 This is a diagram of the second component of the embodiment, viewed from the positive Z-axis direction towards the negative Z-axis direction.

[0015] Figure 4 This is a diagram showing the intermediate component of the embodiment viewed from the positive Z-axis direction towards the negative Z-axis direction.

[0016] Figure 5 This is an enlarged view of the central periphery of the intermediate component 30.

[0017] Figure 6 Is to make Figure 2 The groove forming area shown Figure 3 The groove forming area shown is Figure 4 The diagram shows the overlapping of intermediate components.

[0018] Figure 7 This is a diagram illustrating the flow of the working fluid in the heat dissipation component of the embodiment.

[0019] Figure 8 This is a diagram illustrating the flow of the working fluid in the heat dissipation component of the embodiment.

[0020] Figure 9 yes Figure 8 An enlarged view of section H is shown.

[0021] Figure 10 This is a diagram showing the structure of the through hole in the first modified example.

[0022] Figure 11 This is a diagram showing the structure of the through hole in the second modified example.

[0023] Figure 12 This is a side view of the heat dissipation component in the third variation.

[0024] Figure 13 This is a side view of the heat dissipation component in the fourth variation.

[0025] Figure 14 This is a side view of the heat dissipation component in the fifth variation.

[0026] Figure 15 This is a side view of the heat dissipation component in the sixth variation.

[0027] Figure 16 This is a side view of the heat dissipation component in the seventh variation. Detailed Implementation

[0028] Hereinafter, a mode of a heat dissipating member for embodying the present application (hereinafter, referred to as "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 contradict the processing content. In addition, in each of the embodiments described below, the same reference numerals are assigned to the same parts, and overlapping descriptions are omitted.

[0029] In addition, in the embodiments shown below, expressions such as "constant", "orthogonal", "perpendicular", or "parallel" are sometimes used, but these expressions do not need to be strictly "constant", "orthogonal", "perpendicular", or "parallel". That is, each of the above expressions allows for, for example, a deviation in manufacturing accuracy, setting accuracy, and the like.

[0030] In addition, in each of the drawings referred to below, in order to make the description easy to understand, an orthogonal coordinate system in which an X-axis direction, a Y-axis direction, and a Z-axis direction are defined to be orthogonal to each other and the positive direction of the Z-axis is set as the vertical upward direction is sometimes shown.

[0031] First, with reference to Figure 1 The overall structure of the heat dissipating member of the embodiment will be described. Figure 1 is a perspective view of the heat dissipating member of the embodiment.

[0032] As shown in Figure 1 , the heat dissipating member 1 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 each plate-shaped, and are stacked in a manner that the intermediate member 30 is sandwiched by the first member 10 and the second member 20.

[0033] The heat dissipating member 1 has an internal space in which a working liquid is enclosed. As the working liquid, for example, an organic liquid such as water, a hydrocarbon compound, ethanol, or methanol, or a liquid such as ammonia can be used.

[0034] The first member 10 has a working liquid injection hole 14 and a gas discharge hole 15. The working liquid is injected from the working liquid injection hole 14 into the internal space of the heat dissipating member 1. Along with the injection of the working liquid, the gas present in the internal space of the first member 10 is discharged to the outside from the gas discharge hole 15. The working liquid injection hole 14 is located in the vicinity of one corner of the four corners of the first member 10, and the gas discharge hole 15 is located in the vicinity of the corner that is diagonally opposite to the working liquid injection hole 14.

[0035] The working liquid injection hole 14 and the gas discharge hole 15 are closed by sealing members 4 and 5. By closing the working liquid injection hole 14 and the gas discharge hole 15, the internal space of the heat dissipating member 1 becomes sealed, and the working liquid becomes sealed in the internal space. Thereby, for example, an increase in internal pressure at the time of a high temperature load can be withstood, and heat dissipation can be improved.

[0036] As sealing components 4 and 5, ceramics of the same material as the first component 10, the second component 20, and the intermediate component 30 can be used, for example. Alternatively, ceramics of a different material than the first component 10, the second component 20, and the intermediate component 30 can also be used as sealing components 4 and 5. Furthermore, sealing components 4 and 5 are not limited to ceramics; metals and resins can also be used. Additionally, an adhesive can be placed between the working fluid injection hole 14 and the gas discharge hole 15 and the sealing components 4 and 5. For example, silicone or polyimide resins can be used as this adhesive.

[0037] The working fluid is filled at a ratio of 10% to 95% of the total volume of the internal space of the working area 100. Preferably, the ratio is 30% to 75% of the total volume. More preferably, the ratio is 40% to 65% of the total volume. Furthermore, the remaining portion of the internal space of the heat dissipation member 1, excluding the working fluid, becomes a vacuum state containing a portion of the vaporized working fluid. Therefore, even at high temperatures, a gas-liquid balance can be maintained, making it difficult for the fluid to dry completely. Additionally, heat diffusion is efficient even at low temperatures, thus improving heat diffusivity across various temperature ranges.

[0038] The first component 10, the second component 20, and the intermediate component 30 are made of ceramic. For example, alumina (Al2O3), zirconium oxide (ZrO2), silicon carbide (SiC), silicon nitride (Si3N4), aluminum nitride (AlN), cordierite (Mg2Al3(AlSi5O3)) and other ceramics can be used as the ceramics constituting the first component 10, the second component 20, and the intermediate component 30. 18 (e.g., silicon impregnated silicon carbide (SiSiC)). Additionally, the ceramics constituting the first component 10, the second component 20, and the intermediate component 30 can also be single crystals.

[0039] Metal heat dissipation components are difficult to make rigid and thin due to material and manufacturing process considerations. Furthermore, since the parts of metal heat dissipation components that come into contact with the working fluid are metal, there is room for improvement in corrosion resistance. In contrast, the heat dissipation component 1 of this embodiment, because the first component 10, the second component 20, and the intermediate component 30 are all made of ceramic, is easier to make thinner and exhibits superior corrosion resistance compared to metal heat dissipation components.

[0040] exist Figure 1 In the example shown, the heat dissipation component 1 is positioned so that the first component 10 faces upwards, but the arrangement of the heat dissipation component 1 is not limited to this. Figure 1 For example, the heat dissipation component 1 may also be configured such that the first component 10 faces downwards. Furthermore, the heat dissipation component 1 is not limited to... Figure 1 As shown, it can be placed horizontally, but it can also be placed vertically.

[0041] Next, the structure of the first member 10 will be described with reference to Figure 2 Figure 2 is a view of the first member 10 of the embodiment as viewed from the Z-axis negative direction side toward the Z-axis positive direction.

[0042] In Figure 2 , the lower surface of the first member 10 is shown, specifically, a surface (third surface) opposing the upper surface (first surface) of the intermediate member 30 is shown. As Figure 2 indicated, the first member 10 has a first groove portion 11 in a lattice shape on the third surface.

[0043] The first groove portion 11 has a first recessed portion 11a recessed with respect to the third surface and a plurality of first protruding portions 11b located within the first recessed portion 11a. The first recessed portion 11a is located at the central portion of the third surface, and the outline in plan view is, for example, a quadrangle. The plurality of first protruding portions 11b are arranged in the longitudinal direction (Y-axis direction) and the lateral direction (X-axis direction) at intervals from each other within the first recessed portion 11a. The first groove portion 11 has a lattice shape by the first recessed portion 11a and the plurality of first protruding portions 11b.

[0044] Hereinafter, the region in the third surface of the first member 10 in which the first groove portion 11 is located will be described as a "groove formation region 100". Note that the working fluid injection hole 14 and the gas discharge hole 15 described above are located in the groove formation region 100.

[0045] Next, the structure of the second member 20 will be described with reference to Figure 3 Figure 3 is a view of the second member 20 of the embodiment as viewed from the Z-axis positive direction side toward the Z-axis negative direction.

[0046] In Figure 3 , the upper surface of the second member 20 is shown, specifically, a surface (fourth surface) opposing the lower surface (second surface) of the intermediate member 30 is shown. As Figure 3 indicated, the second member 20 has a second groove portion 21 in a lattice shape on the fourth surface.

[0047] The second groove portion 21 has a second recessed portion 21a recessed with respect to the fourth surface and a plurality of second protruding portions 21b located within the second recessed portion 21a. The second recessed portion 21a is located at the central portion of the fourth surface, and the outline in plan view is, for example, a quadrangle. The plurality of second protruding portions 21b are arranged in the longitudinal direction (Y-axis direction) and the lateral direction (X-axis direction) at intervals from each other within the second recessed portion 21a. The second groove portion 21 has a lattice shape by the second recessed portion 21a and the plurality of second protruding portions 21b.

[0048] ​​Hereinafter, the area where the second groove 21 is located on the fourth surface of the second member 20 will be referred to as "groove forming area 200".

[0049] The size of the groove forming region 200 in the second member 20 is the same as the size of the groove forming region 100 in the first member 10. In addition, the position of the groove forming region 200 on the fourth surface of the second member 20 is the same as the position of the groove forming region 100 on the third surface of the first member 10.

[0050] A heat source is disposed on the lower surface (fifth surface) of the second member 20, which is located on the opposite side of the upper surface (fourth surface).

[0051] In this way, by making the first groove 11 and the second groove 21 into a grid shape, the working fluid can circulate efficiently within the internal space of the heat dissipation component 1. It should be noted that the shape of the first groove 11 and the second groove 21 does not necessarily have to be grid-shaped.

[0052] Next, refer to Figure 4 The structure of intermediate component 30 is described. Figure 4 This is a diagram of the intermediate member 30 of the embodiment, viewed from the positive Z-axis direction towards the negative Z-axis direction.

[0053] like Figure 4 As shown, the intermediate member 30 has: a rectangular frame-shaped edge 31; a circular central portion 32 in plan view, located inside the edge 31; and a plurality of connecting portions 33 located between the central portion 32 and the edge 31, connecting the central portion 32 and the edge 31. Figure 4 In the example shown, the central portion 32 is located at the center of the intermediate member 30. In addition, a plurality of connecting portions 33 are spaced apart from each other and extend radially from the central portion 32 toward the edge portion 31.

[0054] The intermediate component 30 also has a plurality of steam holes 35 and a plurality of through holes 37. The plurality of steam holes 35 and the plurality of through holes 37 all penetrate the upper surface (first surface) and the lower surface (second surface) of the intermediate component 30.

[0055] The multiple vapor holes 35 function as part of the flow path for the working fluid vapor. The multiple vapor holes 35 are located between two adjacent connecting portions 33. That is, the multiple vapor holes 35 and the multiple connecting portions 33 are arranged alternately in the circumferential direction. The multiple vapor holes 35 and the multiple connecting portions 33 are also spaced apart from each other, and extend radially from the central portion 32 toward the edge portion 31.

[0056] Multiple through holes 37 function as part of the flow path for the working fluid. The through holes 37 are micro-holes with a smaller opening area compared to the aforementioned vapor holes 35. Specifically, the through holes 37 are small enough to induce capillary action in the working fluid passing through them.

[0057] Multiple through holes 37 are located in the central portion 32 and multiple connecting portions 33 of the intermediate member 30. Here, refer to... Figure 5 The specific structure of the multiple through holes 37 is explained. Figure 5 This is an enlarged view of the periphery of the central part 32 of the intermediate component 30.

[0058] like Figure 5 As shown, the plurality of through holes 37 include a variety of (three types in this case) through holes with different opening diameters when viewed from the positive Z-axis direction toward the negative Z-axis direction (in other words, the opening diameter on the side of the first member 10). Specifically, they include a plurality of first through holes 37a, a second through hole 37b, and a plurality of third through holes 37c.

[0059] Multiple first through holes 37a are located at each connection portion 33 of the intermediate member 30. For example, the opening diameter of the first through hole 37a as viewed from the side of the first member 10 is, for example, 250 μm or more and 700 μm or less.

[0060] The second through hole 37b is located at the center of the central portion 32 of the intermediate member 30. The diameter of the second through hole 37b is larger than the diameter of the first through hole 37a. For example, the opening diameter of the second through hole 37b as viewed from the side of the first member 10 is, for example, 550 μm or more and 900 μm or less. It should be noted that multiple second through holes 37b may also be provided in the central portion 32.

[0061] Multiple third through holes 37c are located at each connecting portion 33 of the intermediate member 30. Specifically, the multiple third through holes 37c are located in the region near the central portion 32 of the connecting portion 33. In addition, the multiple third through holes 37c are also located in the central portion 32 of the intermediate member 30. Specifically, the multiple third through holes 37c are located in the region near the outer periphery of the central portion 32, i.e., near the connecting portion 33. The diameter of the third through hole 37c is smaller than the diameter of the first through hole 37a. For example, the opening diameter of the third through hole 37c as viewed from the first member 10 side is, for example, 200 to 400 μm.

[0062] Thus, multiple through holes 37 are arranged sequentially from the center of the intermediate member 30 toward the outer periphery: a second through hole 37b with a large opening diameter, a third through hole 37c with a small opening diameter, and a first through hole 37a with a medium opening diameter.

[0063] Compared to the connecting portion 33, the central portion 32 of the intermediate member 30 is farther from the vapor hole 35. Therefore, the backflow of the working fluid is prone to stagnation at the central portion 32. That is, the central portion of the heat dissipation member 1 is prone to becoming an overheating point. In contrast, in the heat dissipation member 1 of the embodiment, by providing a second through hole 37b with a large opening diameter in the central portion 32 of the intermediate member 30, the vapor generated in the central portion 32 can move towards the low-temperature side through the second through hole 37b. This promotes the backflow of the working fluid in the central portion of the heat dissipation member 1. Therefore, it is possible to prevent the central portion of the heat dissipation member 1 from becoming an overheating point.

[0064] The density of through holes 37 at the central portion 32 of the intermediate member 30 is smaller than the density of through holes 37 at the connecting portion 33 of the intermediate member 30. In other words, when viewing the intermediate member 30 from the positive Z-axis direction to the negative Z-axis direction, the proportion of the opening area of ​​the through holes 37 (the second through holes 37b and the plurality of third through holes 37c) to the area of ​​the central portion 32 is smaller than the proportion of the opening area of ​​the through holes 37 (the plurality of first through holes 37a and the plurality of third through holes 37c) to the area of ​​the connecting portion 33. Thus, by making the density of through holes 37 in the central portion 32 relatively small, the reduction in strength of the intermediate member 30 can be suppressed.

[0065] Figure 6 Is to make Figure 2 The groove forming area 100 shown is Figure 3 The groove forming area 200 shown is... Figure 4 The diagram shows the overlapping of intermediate components 30.

[0066] like Figure 6 As shown, the groove forming regions 100 and 200 formed on the first member 10 and the second member 20 overlap with the edge 31 of the intermediate member 30. That is, the groove forming regions 100 and 200 extend outward from the region in the intermediate member 30 where a plurality of vapor holes 35 and a plurality of through holes 37 are formed (hereinafter referred to as "hole forming region").

[0067] In this way, by making the groove forming regions 100 and 200 of the first member 10 and the second member 20 wider than the hole forming region of the intermediate member 30, the internal space of the heat dissipation member 1 can be expanded outward compared to the case where the groove forming regions 100 and 200 are set to the same extent as the hole forming region.

[0068] The heat source is located in the center of the heat dissipation component 1, and the temperature of the heat dissipation component 1 decreases the further away from the heat source, i.e., the closer to the outer periphery of the heat dissipation component 1. Furthermore, the vapor of the working fluid condenses into liquid by moving towards the low-temperature region. Therefore, by expanding the internal space of the heat dissipation component 1 outwards, condensation of the working fluid is more easily generated. Thus, complete drying is less likely to occur.

[0069] Note that, here, an example in which the first groove formation region 110 and the second groove formation region 120 are expanded outwardly than the hole formation region of the intermediate member 30 is shown, but the present application is not limited to this, and the hole formation region of the intermediate member 30 can also be expanded outwardly than the first groove formation region 110 and the second groove formation region 120.

[0070] Next, the flow of the working fluid in the heat dissipating member 1 according to the embodiment will be described with reference to Figure 7 and Figure 8 The flow of the working fluid in the heat dissipating member 1 according to the embodiment will be described. Figure 7 and Figure 8 are diagrams for explaining the flow of the working fluid in the heat dissipating member 1 according to the embodiment. Note that, Figure 7 is a diagram in which the edge portion 31 is omitted from the diagram shown in Figure 6 , Figure 8 is a cross-sectional view taken along the line IX-IX in Figure 7 . Further, in Figure 7 and Figure 8 , the flow of the vapor is indicated by a hollow arrow, and the flow of the liquid is indicated by a blackened arrow.

[0071] The working fluid is vaporized into a vapor by being heated by the heat source. As described above, the heat source is disposed at the central portion of the lower surface (fifth surface) of the second member 20 (refer to Figure 1 , Figure 3 ). Therefore, the vapor of the working fluid is generated at the central portion of the high-temperature-side space (space sandwiched by the second member 20 and the intermediate member 30) in which the heat source is disposed.

[0072] The vapor of the working fluid diffuses in the in-plane direction (XY plane direction) of the heat dissipating member 1 through the groove formation region 200 (second groove portion 21) (refer to the hollow arrow shown in Figure 7 ), and moves to the low-temperature-side space (space sandwiched by the first member 10 and the intermediate member 30) upward through the plurality of vapor holes 35 (refer to the white arrow shown in Figure 8 ).

[0073] The vapor that has moved to the low-temperature-side space is condensed into a liquid due to the decrease in temperature. The liquidized working fluid moves in the groove formation region 100 (first groove portion 11) toward the central portion of the heat dissipating member 1 under the action of the capillary force of the groove formation region 100 (refer to the blackened arrow shown in Figure 7 ). In this process, the working fluid enters the through hole 37, and returns to the high-temperature-side space under the action of the capillary force of the through hole 37 (refer to the blackened arrow shown in Figure 8 ). By repeating the above cycle, the heat dissipating member 1 can move heat from the heat source.

[0074] Next, the flow of the working fluid in the heat dissipating member 1 according to the embodiment will be described with reference to Figure 9The detailed structure of the through-hole 37 formed in the intermediate member 30 will be described. Figure 9 Figure 8 is an enlarged view of the H portion shown in FIG. 6.

[0075] As shown in FIG. 6, the through-hole 37 is tapered from the low-temperature side surface, i.e., the upper surface 301 (first surface) of the plate surface of the intermediate member 30 toward the high-temperature side surface, i.e., the lower surface 302 (second surface). In other words, the opening diameter of the through-hole 37 is narrowed from the low-temperature side toward the high-temperature side. Figure 9 By relatively increasing the opening diameter of the low-temperature side of the through-hole 37, the working fluid easily enters the through-hole 37. In addition, by making the opening diameter of the high-temperature side of the through-hole 37 relatively small, the magnitude of the capillary force in the through-hole 37 can be made to increase as it approaches the high-temperature side. Thus, the working fluid that has entered the through-hole 37 from the low-temperature side can be pulled toward the high-temperature side with acceleration using the capillary force that gradually increases.

[0076] Thus, according to the heat dissipating member 1, by forming the through-hole 37 in a tapered shape, the circulation efficiency of the working fluid can be improved. In addition, according to the heat dissipating member 1, by forming the through-hole 37 in a tapered shape, the backflow of the working fluid and the vapor can also be suppressed.

[0077] Note that, as described above, the second through-hole 37b (see FIG. 6) among the plurality of through-holes 37 is also used as a flow path for the vapor. Therefore, the second through-hole 37b can also be formed in a straight line shape with a constant opening diameter so that the vapor easily moves.

[0078] Figure 5 The surface roughness of the inner surface 371 of the through-hole 37 is greater than the surface roughness of the upper surface 301 (first surface) of the intermediate member 30. The greater the surface roughness, the higher the wettability. Therefore, the working fluid easily enters the inside of the through-hole 37 having a greater surface roughness.

[0079] Thus, by making the surface roughness of the inner surface 371 of the through-hole 37 greater than the surface roughness of the upper surface 301 (first surface) of the intermediate member 30, the circulation efficiency of the working fluid can be improved.

[0080] In addition, the surface roughness of the inner surface 211 of the second groove portion 21 is greater than the surface roughness of the inner surface 371 of the through-hole 37. Thus, the working fluid easily drains from the inside of the through-hole 37 to the second groove portion 21.

[0081] Thus, by making the surface roughness of the inner surface 211 of the second groove portion 21 greater than the surface roughness of the inner surface 371 of the through-hole 37, the circulation efficiency of the working fluid can be improved.

[0082] Thus, by making the surface roughness of the inner surface 211 of the second groove portion 21 greater than the surface roughness of the inner surface 371 of the through-hole 37, the circulation efficiency of the working fluid can be improved.

[0083] ​​Next, an example of a manufacturing method of the heat dissipating member 1 described above will be described. First, using raw materials of the first member 10, the second member 20, and the intermediate member 30, green sheets are formed by a doctor blade method or a roll press method or the like, and a plurality of the green sheets are stacked, thereby obtaining a laminate.

[0084] Next, by performing laser processing on the obtained laminate and punching using a die, each of the first member 10, the second member 20, and the intermediate member 30 is obtained. For example, by performing laser processing on the laminate, a formed body of the intermediate member 30 in which a plurality of vapor holes 35 and a plurality of through holes 37 are formed can be obtained. By the laser processing at this time, the surface roughness of the inner surface 371 of the through hole 37 can be made larger than the surface roughness of the upper surface 301 (first surface) of the intermediate member 30.

[0085] In addition, by performing laser processing on the obtained laminate, formed bodies of the first member 10 and the second member 20 in which the groove forming regions 100, 200 are formed are obtained. By adjusting the output of the laser in the laser processing at this time, the surface roughness of the inner surface 211 of the second groove portion 21 can be made larger than the surface roughness of the inner surface 371 of the through hole 37.

[0086] Next, each of the formed bodies of the first member 10, the second member 20, and the intermediate member 30 is stacked in the order of the second member 20, the intermediate member 30, and the first member 10 and is fired, thereby obtaining a fired body 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 formed. Therefore, since an adhesive or the like is not needed, a heat dissipating member 1 with high reliability can be obtained.

[0087] Next, a working fluid is injected into the inside of the fired body from the working fluid injection hole 14 provided in the first member 10. The gas present in the inside of the fired body is discharged to the outside from the gas discharge hole 15 of the first member 10 along with the injection of the working fluid.

[0088] Next, the working fluid injection hole 14 and the gas discharge hole 15 are closed using the sealing members 4, 5 and an adhesive. Thereby, the heat dissipating member 1 is obtained.

[0089] (First Modified Example)

[0090] Figure 10 is a view showing the structure of the through hole of the first modified example. As shown in Figure 10 The heat dissipating member 1A of the first modified example has an intermediate member 30A.

[0091] The intermediate member 30A of the first modification example has a chamfered portion 372 between the upper surface 301 (first surface) and the through-hole 37. The chamfered portion 372 has, for example, a curved convex surface that connects the upper surface 301 (first surface) and the inner surface 371 of the through-hole 37.

[0092] Thus, by providing the chamfered portion 372 between the upper surface 301 (first surface) and the through-hole 37, the working fluid can be easily introduced into the through-hole 37.

[0093] Note that the chamfered portion 372 does not necessarily have to be curved (rounded), and can be flat (edged), for example.

[0094] In the case of manufacturing a shaped body of the intermediate member 30A having the chamfered portion 372, for example, in the case of performing laser processing on the laminate of green sheets, or in the case of punching using a die, the output of the laser processing or the shape of the die can be adjusted. Then, by firing the obtained shaped body together with the first member 10 and the second member 20, a fired body in which the first member 10, the second member 20, and the intermediate member 30A are integrated can be obtained.

[0095] (Second Modification Example)

[0096] Figure 11 is a view that shows the structure of the through-hole of the second modification example. As shown in Figure 11 , the heat dissipation member 1B of the second modification example has an intermediate member 30B.

[0097] The intermediate member 30B of the second modification example meanders with respect to the XY plane. Also, the heat dissipation member 1B has a first gap 310 between at least one of the plurality of first protrusions 11b that the first groove portion 11 has and the upper surface 301 of the intermediate member 30B.

[0098] According to this heat dissipation member 1B, not only the working fluid can circulate in the first groove portion 11, but also the working fluid can circulate in the first gap 310. The working fluid is guided to the through-hole 37 and introduced into the through-hole 37 by the capillary force in the first gap 310. Thus, according to the heat dissipation member 1B, by having the first gap 310, the circulation efficiency of the working fluid can be further improved.

[0099] In addition, the heat dissipation member 1B has a second gap 320 between at least one of the plurality of second protrusions 21b that the second groove portion 21 has and the lower surface 302 of the intermediate member 30B.

[0100] According to the heat dissipation member 1B, not only the vapor of the working fluid can flow in the second groove portion 21, but also the vapor of the working fluid can flow in the second gap 320. Thus, according to the heat dissipation member 1B, by having the second gap 320, the diffusion of the vapor of the working fluid can be promoted. That is, the circulation efficiency of the working fluid can be improved.

[0101] In the case where the shaped body of the intermediate member 30B that meanders with respect to the XY plane is manufactured, for example, it is only necessary to adjust the pressure applied to the laminate at the time of laminating the green sheet. For example, by applying the pressure to the laminate unevenly, the shaped body of the intermediate member 30B that meanders with respect to the XY plane can be obtained. Then, by firing the obtained shaped body together with the first member 10 and the second member 20, the fired body in which the first member 10, the second member 20, and the intermediate member 30B are integrated can be obtained.

[0102] In addition, the surface roughness of the inner surface 211 of the second groove portion 21 is larger than the surface roughness of the lower surface 302 (second surface) of the intermediate member 30. Thereby, the working fluid is easily discharged from the lower surface 302 (second surface) of the intermediate member 30 to the second groove portion 21.

[0103] Thus, by making the surface roughness of the inner surface 211 of the second groove portion 21 larger than the surface roughness of the lower surface 302 (second surface) of the intermediate member 30, the circulation efficiency of the working fluid can be improved.

[0104] Note that the surface roughness of the upper surface 301 (first surface) of the intermediate member 30, the inner surface 371 of the through-hole 37, the lower surface 302 (second surface), and the inner surface 211 of the second groove portion 21 may, for example, be adjusted to be in the range of 0.08 μm or more and 0.4 μm or less, 0.3 μm or more and 0.6 μm or less, 0.08 μm or more and 0.4 μm or less, or 0.5 μm or more and 0.8 μm or less in arithmetic mean roughness Ra, respectively.

[0105] (Third Modified Example)

[0106] Figure 12 is a side view of the heat dissipation member of the third modified example. As shown in Figure 12 The heat dissipation member 1C can also have the conductor 6 on the lower surface (fifth surface) of the second member 20, which is the high-temperature side.

[0107] Since the heat dissipation member made of metal is a conductor itself, it is necessary to provide an insulator in order to form a circuit or the like. In contrast, according to the heat dissipation member 1C composed of ceramic as an insulator, by using the conductor 6 as a wiring or an electrode, an electronic component can be directly mounted.

[0108] (Fourth Modified Example)

[0109] Figure 13 is a side view of a heat dissipating member of a fourth modification. As shown in Figure 13 , the heat dissipating member 1D can also have a cover layer 7 covering at least a part of the conductor 6 on the lower surface (fifth surface) of the second member 20 as the high-temperature side.

[0110] (Fifth Modification)

[0111] Figure 14 is a side view of a heat dissipating member of a fifth modification. As shown in Figure 14 , the heat dissipating member 1E can also have a heat sink 8 on the upper surface (sixth surface) of the first member 10 as the low-temperature side. The material of the heat sink 8 can be either metal or ceramic. The heat sink 8 has, for example, a plurality of fins 81. Thereby, the heat dissipating effect can be further improved.

[0112] (Sixth Modification)

[0113] Figure 15 is a side view of a heat dissipating member of a sixth modification. As shown in Figure 15 , the heat dissipating member 1F can also have a first member 10F having a plurality of fins 18 composed of ceramic integrally formed on the upper surface (sixth surface). The first member 10F is obtained, for example, by firing a formed body having the plurality of fins 18 formed by punching using a mold or laser processing on a laminated body of green sheets. According to this heat dissipating member 1F, an adhesive or the like for mounting the fins 18 is not needed, and thus the reliability can be improved. In addition, the heat dissipation is not hindered by the adhesive or the like.

[0114] A part of the plurality of fins 18 is preferably located outward of the groove formation region 100 of the first member 10F, the groove formation region 200 of the second member 20, and the internal space of the heat dissipating member 1F formed by the vapor hole 35 and the through hole 37 of the intermediate member 30. Thereby, the heat dissipating effect can be further improved.

[0115] (Seventh Modification)

[0116] Figure 16 is a side view of a heat dissipating member of a seventh modification. As shown in Figure 16 , the heat dissipating member 1G can also have a temperature regulating plate 9 on the upper surface (sixth surface) of the first member 10 as the low-temperature side. The temperature regulating plate 9 can be, for example, a water-cooled, air-cooled, or resistance-heated temperature regulating plate.

[0117] As described above, the heat dissipating member (as one example, heat dissipating members 1, 1A to 1G) of the embodiment has an intermediate member (as one example, intermediate members 30, 30A, 30B) composed of ceramic and flat plate shape, a first member (as one example, first members 10, 10F), and a second member (as one example, second member 20). The intermediate member has a plurality of through holes (as one example, through holes 37) that penetrate a first face (as one example, upper face 301) and a second face (as one example, lower face 302) located on opposite sides of each other. The first member has a first groove portion (as one example, first groove portion 11) on a third face (as one example, lower face) that opposes the first face of the intermediate member. The second member has a plurality of second groove portions (as one example, second groove portions 21) on a fourth face (as one example, upper face) that opposes the second face of the intermediate member, and a heat source is disposed on a fifth face (as one example, lower face) located on the opposite side of the fourth face. In addition, for the intermediate member, the surface roughness of the inner surface of the through hole is greater than the surface roughness of the first face. Thus, the working fluid easily enters the inside of the through hole, and therefore the circulation efficiency of the working fluid can be improved. Therefore, further improvement of the heat dissipating efficiency can be achieved.

[0118] The first groove portion and the second groove portion are in a lattice shape. Thus, the working fluid can be efficiently circulated in the internal space of the heat dissipating member.

[0119] The surface roughness of the inner surface of the second groove portion is greater than the surface roughness of the inner surface of the through hole. Thus, the working fluid easily drains from the inside of the through hole to the second groove portion, and therefore the circulation efficiency of the working fluid can be improved.

[0120] The first groove portion has a first recessed portion (as one example, first recessed portion 11a) recessed with respect to the third face, and a plurality of first protrusions (first protrusions 11b) located in the first recessed portion. In addition, the heat dissipating member of the embodiment has a gap (as one example, first gap 310) between at least one of the plurality of first protrusions and the first face. Thus, the working fluid not only flows in the first groove portion but also flows in the above-described gap, and therefore the circulation efficiency of the working fluid can be improved.

[0121] The second groove portion has a second recessed portion (as one example, second recessed portion 21a) recessed with respect to the fourth face, and a plurality of second protrusions (as one example, second protrusions 21b) located in the second recessed portion. In addition, the heat dissipating member of the embodiment has a gap (as one example, second gap 320) between at least one of the plurality of second protrusions and the second face. Thus, the vapor of the working fluid not only flows in the second groove portion but also flows in the above-described gap, and therefore the circulation efficiency of the working fluid can be improved.

[0122] The intermediate member has a rim portion (e.g., rim portion 31), a central portion (e.g., central portion 32), and a plurality of connecting portions (e.g., connecting portion 33) that are located between the central portion and the rim portion and connect the central portion and the rim portion. In addition, the plurality of through holes include a plurality of first through holes (e.g., first through hole 37a) located at the connecting portions and at least one second through hole (e.g., second through hole 37b) located at the central portion and having a larger opening area than the first through holes. By providing the second through hole having a large opening diameter at the central portion of the intermediate member, it is possible to suppress the central portion of the heat dissipation member from becoming a hot spot.

[0123] In plan view, the first groove portion and the second groove portion overlap the rim portion. By expanding the inner space of the heat dissipation member outward, condensation of the working fluid is likely to occur, and thus it is possible to make it difficult to dry out.

[0124] The through hole is tapered from the first face side toward the second face side. By relatively increasing the opening diameter on the low-temperature side, it is possible to make it easy for the working fluid to enter the through hole. In addition, by making the opening diameter on the high-temperature side relatively small, it is possible to make the magnitude of the capillary force in the through hole larger as it approaches the high-temperature side. Thus, it is possible to improve the circulation efficiency of the working fluid. That is, it is possible to achieve further improvement in heat dissipation efficiency.

[0125] The intermediate member has a chamfer portion (e.g., chamfer portion 372) between the first face and the through hole. Thereby, it is possible to make it easy for the working fluid to enter the through hole.

[0126] Note that, although in the above-described embodiments and modified examples, examples in which the shape of the through hole is tapered (conical) from the first face side of the intermediate member toward the second face side are described, the shape of the through hole is not limited to conical. For example, the shape of the through hole can be tapered (inverted conical) from the first face side of the intermediate member toward the second face side. In addition, the shape of the through hole can be substantially constant (straight) from the first face side of the intermediate member to the second face side.

[0127] It should be considered that the embodiments disclosed herein are illustrative in all aspects and are not restrictive. In fact, the above-described embodiments can be embodied in various ways. In addition, the above-described embodiments can be omitted, replaced, and changed in various ways without departing from the appended technical solutions and their spirits.

[0128] Explanation of Reference Signs:

[0129] 1: Heat dissipation member

[0130] 4, 5: Sealing member

[0131] 6: Conductor

[0132] 7: Cover layer

[0133] 8: Heat sink

[0134] 9: Temperature adjustment plate

[0135] 10: First member

[0136] 11: First groove portion

[0137] 11a: First recessed portion

[0138] 11b: First protruding portion

[0139] 14: Working fluid injection hole

[0140] 15: Gas discharge hole

[0141] 20: Second member

[0142] 21: Second groove portion

[0143] 21a: Second recessed portion

[0144] 21b: Second protruding portion

[0145] 30: Intermediate member

[0146] 31: Rim portion

[0147] 32: Central portion

[0148] 33: Connection portion

[0149] 35: Vapor hole

[0150] 37: Through hole

[0151] 37a: First through hole

[0152] 37b: Second through hole

[0153] 37c: Third through hole

[0154] 100: Groove formation region

[0155] 200: Groove formation region.

Claims

1. A heat dissipating member, wherein the heat dissipating member has: an intermediate member composed of ceramic and flat plate-shaped, and having a plurality of through holes penetrating a first face and a second face located on opposite sides of each other and a plurality of vapor holes; a first member composed of ceramic and flat plate-shaped, and having a first groove portion on a third face opposed to the first face of the intermediate member; and a second member composed of ceramic and flat plate-shaped, and having a plurality of second groove portions on a fourth face opposed to the second face of the intermediate member, and a heat source is disposed on a fifth face located on the opposite side of the fourth face, the plurality of vapor holes function as a part of a flow path of vapor of a working fluid, the plurality of through holes function as a part of a flow path of the working fluid, the through holes being fine holes having a smaller opening area than the vapor holes, the through holes being so small as to be able to cause capillary phenomenon of the working fluid passing through the through holes, for the intermediate member, a surface roughness of an inner surface of the second groove portion is larger than a surface roughness of an inner surface of the through hole.

2. The heat dissipating member according to claim 1, wherein for the intermediate member, a surface roughness of an inner surface of the through hole is larger than a surface roughness of the first face.

3. The heat dissipating member according to claim 1, wherein the through hole is tapered in diameter from the first face side toward the second face side.

4. The heat dissipating member according to any one of claims 1 to 3, wherein a surface roughness of an inner surface of the second groove portion is larger than a surface roughness of the second face of the intermediate member.

5. The heat dissipating member according to any one of claims 1 to 3, wherein the first groove portion and the second groove portion are in a lattice shape.

6. The heat dissipating member according to any one of claims 1 to 3, wherein the intermediate member has a chamfer portion between the first face and the through hole.

7. The heat dissipating member according to any one of claims 1 to 3, wherein the first groove portion has a first recessed portion recessed with respect to the third face and a plurality of first protruding portions located in the first recessed portion, a gap is provided between at least one of the plurality of first protruding portions and the first face.

8. The heat dissipating member according to any one of claims 1 to 3, wherein the second groove portion has a second recessed portion recessed with respect to the fourth face and a plurality of second protruding portions located in the second recessed portion, a gap is provided between at least one of the plurality of second protruding portions and the second face.

9. The heat dissipating member according to any one of claims 1 to 3, wherein the intermediate member has a rim portion, a central portion, and a plurality of connecting portions located between the central portion and the rim portion and connecting the central portion and the rim portion to each other, the plurality of through holes include a plurality of first through holes located in the connecting portions and at least one second through hole located in the central portion and having a larger opening area than the first through holes.

10. The heat dissipating member according to claim 9, wherein a density of the through holes of the central portion is smaller than a density of the through holes of the connecting portions. ​ 11. The heat dissipation component according to any one of claims 1 to 3, wherein, The intermediate member has an edge portion, a central portion, and a plurality of connecting portions located between the central portion and the edge portion and connecting the central portion and the edge portion. When viewed from above, the first groove and the second groove overlap with the edge.

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