Thermal diffusion device and electronic apparatus

Abstract

The utility model relates to a thermal diffusion device and electronic equipment. A heat diffusion device (1) is provided with: a housing (10) having a first inner wall surface (11a) and a second inner wall surface (12a) which face each other in the thickness direction (Z); a working medium (20) sealed in the internal space of the housing (10); and a core body (30) disposed in the internal space of the frame body (10). The core body (30) includes a support body (31) in contact with the first inner wall surface (11a), and a perforated body (32) in contact with the support body (31). The perforated body (32) has a through-hole (33) penetrating in the thickness direction (Z). Protrusions (34) are provided on the periphery of the through-hole (33) in a direction approaching the second inner wall surface (12a).

Description

[0001] This application is a divisional application of application No. 2023 9 0000 197.1 (International Application No. PCT / JP2023 / 000092), filed on January 5, 2023, entitled "Heat Diffusion Device and Electronic Equipment". Technical Field

[0002] This utility model relates to heat diffusion devices and electronic devices. Background Technology

[0003] In recent years, the increasing integration and performance of components have led to a rise in heat generation. Furthermore, with the miniaturization of products, heat density has increased, making heat dissipation strategies crucial. This is particularly evident in mobile devices such as smartphones and tablets. While graphite sheets are commonly used as heat dissipation components, their heat transfer capacity is insufficient, prompting research into various heat dissipation components. Among these, research is underway on the use of planar heat pipes, also known as vapor chambers, as heat dissipation devices that can effectively diffuse heat.

[0004] A vapor chamber has a structure in which a working medium (also called a working fluid) is sealed inside a frame, and a core is used to transport the working medium using capillary force. The working medium absorbs heat from heating elements such as electronic components in an evaporation section, evaporates within the vapor chamber, moves within the vapor chamber, is cooled, and returns to a liquid phase. The working medium, now back to a liquid phase, moves again towards the evaporation section on the heating element side using the capillary force of the core, cooling the heating element. By repeating this process, the vapor chamber can operate independently without external power, utilizing the latent heat of vaporization and condensation of the working medium to achieve two-dimensional and high-speed heat diffusion.

[0005] Patent Document 1 discloses a thermal groundplane as an example of a heat spreader. The thermal groundplane described in Patent Document 1 comprises: a first planar substrate member; a plurality of micropillars disposed on the first planar substrate member; a mesh bonded to at least a portion of the micropillars; a vapor core disposed on at least one of the first planar substrate member, the micropillars, and the mesh; and a second planar substrate member disposed on the first planar substrate member, wherein the mesh separates the micropillars from the vapor core, and the first and second planar substrate members surround the micropillars, the mesh, and the vapor core.

[0006] Patent Document 1: U.S. Patent No. 10,527,358

[0007] In the vapor chamber described in Patent Document 1, the core is composed of a porous body such as micropillars and a mesh. The porous body of the vapor chamber can be a porous body with holes formed in a metal plate through etching or other processes. In such a porous body, the surface of the porous body in contact with the vapor layer is coplanar with the surface surrounded by the periphery of the holes. Since the liquid surface of the working medium inside the holes is in contact with the vapor layer, the flow of steam in the vapor layer has a significant impact on the working medium inside the holes. Therefore, in the vapor chamber described in Patent Document 1, the core is easily affected by the flow of steam in the direction opposite to the capillary force, a phenomenon known as countercurrent. This countercurrent reduces the capillary force of the core, leading to a decrease in the maximum heat transfer capacity of the vapor chamber. Utility Model Content

[0008] This invention was made to solve the above-mentioned problems, and its purpose is to provide a heat diffusion device that can improve the maximum heat transfer. Furthermore, this invention aims to provide an electronic device incorporating the aforementioned heat diffusion device.

[0009] The heat diffusion device of this utility model comprises: a frame having a first inner wall surface and a second inner wall surface facing each other in the thickness direction; a working medium sealed in the internal space of the frame; and a core disposed in the internal space of the frame. The core includes a support body that contacts the first inner wall surface and a perforated body that contacts the support body. The perforated body has a through hole that extends along the thickness direction. The support body has a recessed portion, and a protrusion is provided around the periphery of the through hole in a direction close to the second inner wall surface.

[0010] Alternatively, the protrusion may have a first end against the first inner wall surface and a second end against the second inner wall surface, wherein when viewed from the thickness direction, the cross-sectional area of ​​the region enclosed by the inner wall at the second end is smaller than the cross-sectional area of ​​the region enclosed by the inner wall at the first end.

[0011] Alternatively, when viewed from the thickness direction, the inner wall of the second end is located on the inner side of the first end.

[0012] Alternatively, in a cross-section along the aforementioned thickness direction, the aforementioned protrusion has a tapered shape in which the distance between the outer walls of the aforementioned protrusion narrows as it approaches the aforementioned second inner wall surface.

[0013] Alternatively, the protrusion may have a first end against the first inner wall surface and a second end against the second inner wall surface, wherein when viewed from the thickness direction, the cross-sectional area of ​​the region enclosed by the inner wall at the second end is larger than the cross-sectional area of ​​the region enclosed by the inner wall at the first end.

[0014] Alternatively, when viewed from the thickness direction, the inner wall of the second end is located on the outer side compared to the inner wall of the first end.

[0015] Alternatively, the protrusion may have a cover at the second end that narrows the opening of the protrusion.

[0016] Alternatively, the thickness of the support body may be the same as the thickness of the perforated body, or the thickness of the support body may be smaller than the thickness of the perforated body.

[0017] Alternatively, the porous body may be made of the same material as the support body.

[0018] Alternatively, the porous body may be made of a different material than the support body.

[0019] Alternatively, the aforementioned support may include multiple columnar components.

[0020] Alternatively, the aforementioned support may include multiple track-shaped components.

[0021] Alternatively, in relation to the aforementioned through-hole, a through-hole with capillary force may be provided.

[0022] Alternatively, the recessed portion of the aforementioned support body may be formed by stamping.

[0023] Alternatively, the aforementioned through hole and protrusion may be formed by stamping.

[0024] Alternatively, the core can be formed by simultaneously performing stamping processes to form the support body and to form the through hole and the protrusion.

[0025] The electronic device of this invention includes the heat diffusion device of this invention.

[0026] According to this invention, a heat diffusion device capable of increasing maximum heat transfer can be provided. Furthermore, according to this invention, an electronic device incorporating the aforementioned heat diffusion device can be provided. Attached Figure Description

[0027] Figure 1 This is a perspective view schematically illustrating an example of the heat diffusion device of this invention.

[0028] Figure 2 yes Figure 1 An example of a cross-sectional view of a heat diffusion device along line II-II.

[0029] Figure 3 A is a schematic representation of the composition. Figure 2 An enlarged partial cross-sectional view of an example of the core of the heat diffusion device shown. Figure 3 B is a schematic representation. Figure 3 A three-dimensional view of the shape of the protrusion of the core shown in Figure A. Figure 3 The C is schematically represented. Figure 3 A perspective view of another example of the shape of the protrusion of the core shown in A.

[0030] Figure 4 A is viewed from the support side. Figure 3 An example of a top view of the core shown in Figure A. Figure 4 B is viewed from the support side. Figure 3 Another example of a top view of the core shown in Figure A.

[0031] Figure 5 It is a schematic representation of the view from the side of the perforated body. Figure 3 A top view of the core shown in Figure A, including the through-hole, the protrusion, and the steam flow near the protrusion.

[0032] Figure 6 A is an enlarged cross-sectional view schematically representing a first modified example of the convex portion. Figure 6 B is a schematic representation. Figure 6 A three-dimensional view of the shape of the convex part shown in Figure A.

[0033] Figure 7 A is an enlarged cross-sectional view schematically representing a second variant of the convex portion. Figure 7 B is a schematic representation. Figure 7 A three-dimensional view of the shape of the convex part shown in Figure A.

[0034] Figure 8-1 A is a partially enlarged cross-sectional view schematically representing a third variation of the convex portion. Figure 8-1 B is a schematic representation. Figure 8-1 A three-dimensional view of the shape of the convex part shown in Figure A.

[0035] Figure 8-2 A is a schematic representation. Figure 8-1 Another example of a convex part shown in A is an enlarged partial cross-sectional view. Figure 8-2 B is a schematic representation. Figure 8-2 A three-dimensional view of the shape of the convex part shown in Figure A.

[0036] Figure 8-3 A is a schematic representation. Figure 8-1 Another example of a convex part shown in A is an enlarged partial cross-sectional view. Figure 8-3 B is a schematic representation. Figure 8-3 A three-dimensional view of the shape of the convex part shown in Figure A.

[0037] Figure 9 This is an enlarged cross-sectional view schematically representing a fourth modified example of the convex portion.

[0038] Figure 10 This is an enlarged cross-sectional view schematically representing a fifth variation of the convex portion.

[0039] Figure 11 It is a schematically enlarged cross-sectional view of a first modified example of the core.

[0040] Figure 12 It is a schematic representation Figure 11 The enlarged cross-sectional view of a first modified example of the protrusion in the core shown.

[0041] Figure 13 It is a schematic representation Figure 11 The enlarged partial cross-sectional view of the second modified example of the protrusion in the core shown.

[0042] Figure 14 This is an enlarged cross-sectional view schematically representing a second variant of the core.

[0043] Figure 15 This is a top view schematically representing a third variation of the core.

[0044] Figure 16 This is a cross-sectional view schematically representing a first modified example of a heat diffusion device.

[0045] Figure 17 This is a cross-sectional view schematically representing a second modified example of a heat diffusion device.

[0046] Figure 18 Viewed from the side of the perforated body Figure 3 A top view of the first modified example of the core shown in Figure A.

[0047] Figure 19 yes Figure 18 The core shown is a cross-sectional view along line AA.

[0048] Figure 20 It is used for explanation Figure 12 A diagram showing the definition of the protrusions in the core.

[0049] Figure 21 It is used for explanation Figure 19 A diagram showing the definition of the protrusions in the core. Detailed Implementation

[0050] The heat diffusion device of this utility model will be described below.

[0051] However, this invention is not limited to the following embodiments, and can be applied by appropriate modifications without changing the spirit of this invention. Furthermore, this invention also includes structures that combine two or more of the preferred structures described below.

[0052] The following description uses a heat spreader as an example to illustrate one embodiment of the heat diffusion device of this invention. The heat diffusion device of this invention can also be applied to heat pipes and other heat diffusion devices.

[0053] The accompanying drawings are schematic and their dimensions, aspect ratios, and scales may differ from the actual product.

[0054] Figure 1 This is a perspective view schematically illustrating an example of the heat diffusion device of this invention. Figure 2 yes Figure 1 An example of a cross-sectional view of a heat diffusion device along line II-II.

[0055] Figure 1 and Figure 2 The vapor chamber (heat diffusion device) 1 shown has a hollow frame 10 that is sealed in an airtight state. The frame 10 has a first inner wall surface 11a and a second inner wall surface 12a facing each other in the thickness direction Z. The vapor chamber 1 also includes: a working medium 20, which is sealed in the internal space of the frame 10; and a core 30, which is disposed in the internal space of the frame 10.

[0056] An evaporation section is provided in the frame 10 for evaporating the sealed working medium 20. For example... Figure 1 As shown, a heat source HS, serving as a heating element, is disposed on the outer wall of the housing 10. Examples of heat sources HS include electronic components of electronic devices, such as central processing units (CPUs). Within the interior space of the housing 10, the portion near the heat source HS, i.e., the portion heated by the heat source HS, corresponds to an evaporation section.

[0057] The heat spreader 1 is preferably integrally planar. That is, the frame 10 is preferably integrally planar. Here, "planar" includes plate-like and sheet-like shapes, which refers to a shape in which the dimension in the width direction X (hereinafter referred to as width) and the dimension in the length direction Y (hereinafter referred to as length) are relatively large relative to the dimension in the thickness direction Z (hereinafter referred to as thickness or height), for example, a shape in which the width and length are 10 times or more than the thickness, preferably 100 times or more.

[0058] The size of the heat spreader 1, i.e., the size of the frame 10, is not particularly limited. The width and length of the heat spreader 1 can be appropriately set according to the application. For example, the width and length of the heat spreader 1 can be 5mm to 500mm, 20mm to 300mm, or 50mm to 200mm. The width and length of the heat spreader 1 can be the same or different.

[0059] The frame 10 is preferably composed of opposing first sheets 11 and second sheets 12 whose outer edges are joined together.

[0060] When the frame 10 is composed of a first sheet 11 and a second sheet 12, the materials constituting the first sheet 11 and the second sheet 12 are not particularly limited as long as they possess properties suitable for use as a heat spreader, such as thermal conductivity, strength, flexibility, etc. The materials constituting the first sheet 11 and the second sheet 12 are preferably metals, such as copper, nickel, aluminum, magnesium, titanium, iron, or alloys with these as their main components, with copper being particularly preferred. The materials constituting the first sheet 11 and the second sheet 12 may be the same or different, but they are preferably the same.

[0061] When the frame 10 is composed of a first sheet 11 and a second sheet 12, the first sheet 11 and the second sheet 12 are joined together at their outer edges. The joining method is not particularly limited, and for example, laser welding, resistance welding, diffusion bonding, brazing, TIG welding (tungsten inert gas welding), ultrasonic bonding, or resin sealing can be used. Laser welding, resistance welding, or brazing is preferred.

[0062] The thickness of the first sheet 11 and the second sheet 12 is not particularly limited, but is preferably 10 μm to 200 μm, more preferably 30 μm to 100 μm, and even more preferably 40 μm to 60 μm. The thickness of the first sheet 11 and the second sheet 12 may be the same or different. In addition, the thickness of each sheet of the first sheet 11 and the second sheet 12 may be the same overall or partially thinner.

[0063] The shapes of the first sheet 11 and the second sheet 12 are not particularly limited. For example, the first sheet 11 and the second sheet 12 may also be shaped such that the outer edge is thicker than the portion outside the outer edge.

[0064] The overall thickness of the heat spreader 1 is not particularly limited, but is preferably 50μm or more and 500μm or less.

[0065] The planar shape of the frame 10 viewed from the thickness direction Z is not particularly limited. Examples include polygons such as triangles or rectangles, circles, ellipses, and shapes formed by combining them. Additionally, the planar shape of the frame 10 can also be L-shaped, C-shaped (ココん ...

[0066] The working medium 20 is not particularly limited as long as it can produce a gas-liquid phase change within the environment of the housing 10; for example, water, alcohols, or Freon substitutes can be used. For example, the working medium 20 is an aqueous compound, preferably water.

[0067] The core 30 has a capillary structure that enables the working medium 20 to move using capillary force.

[0068] The size and shape of the core 30 are not particularly limited, but for example, it is preferable that the core 30 is continuously disposed in the internal space of the frame 10. The core 30 may be disposed as a whole in the internal space of the frame 10 when viewed from the thickness direction Z, or the core 30 may be disposed as a part of the internal space of the frame 10 when viewed from the thickness direction Z.

[0069] Figure 3 A is a schematic representation of the composition. Figure 2 An enlarged partial cross-sectional view of an example of the core of the heat diffusion device shown.

[0070] like Figure 2 and Figure 3 As shown in A, the core 30 includes a support 31 that contacts the first inner wall surface 11a and a perforated body 32 that contacts the support 31.

[0071] In the core 30, the porous body 32 is made of the same material as the support 31. When the porous body 32 is made of the same material as the support 31, the materials constituting the support 31 and the porous body 32 are not particularly limited; examples include resin, metal, ceramic, or mixtures or laminates thereof. The preferred materials constituting the support 31 and the porous body 32 are metals.

[0072] In the core 30, the support 31 and the perforated body 32 can be integrally formed. In this specification, "the support 31 and the perforated body 32 are integrally formed" means that there is no interface between the support 31 and the perforated body 32, specifically, that the boundary between the support 31 and the perforated body 32 cannot be determined.

[0073] The core 30, which is integrally formed by the support 31 and the perforated body 32, can be manufactured, for example, by etching technology, printing technology based on multilayer coating, other multilayer technology, etc.

[0074] In the core 30, if the perforated body 32 is made of the same material as the support 31, the support 31 and the perforated body 32 may not be integrally formed. For example, in a core 30 where the copper pillar serving as the support 31 and the copper mesh serving as the perforated body 32 are fixed by diffusion bonding or spot welding, a gap may occur between the support 31 and the perforated body 32 because it is difficult to bond them across the entire surface. In such a core 30, since the boundary between the support 31 and the perforated body 32 can be distinguished, it can be said that the support 31 and the perforated body 32 are not integrally formed, but the perforated body 32 is made of the same material as the support 31.

[0075] Figure 4 A is viewed from the support side. Figure 3 An example of a top view of the core shown in Figure A. Figure 4 B is viewed from the support side. Figure 3 Another example of a top view of the core shown in Figure A.

[0076] In the core 30, the support 31 includes, for example, a plurality of columnar components. By maintaining the working medium 20 in liquid phase between the columnar components, the heat transfer performance of the heat spreader 1 can be improved. Here, "columnar" refers to a shape in which the ratio of the length of the long side of the bottom surface to the length of the short side of the bottom surface is less than 5 times.

[0077] The shape of the columnar component is not particularly limited; for example, cylindrical, prism, frustum-shaped, and pyramidal shapes can be listed. Figure 4 In the example shown in A, the cross-sectional shape of the support 31 perpendicular to the height direction is quadrilateral. Figure 4 In the example shown in B, the cross-sectional shape of the support 31 perpendicular to the height direction is circular.

[0078] The columnar component only needs to be relatively higher than its surroundings. Therefore, in addition to the portion protruding from the first inner wall surface 11a, the columnar component also includes a portion whose height is relatively increased due to the recess formed in the first inner wall surface 11a.

[0079] The shape of the support 31 is not particularly limited, such as Figure 2 and Figure 3 As shown in Figure A, the support 31 preferably has a tapered shape in which the width narrows as it moves from the perforated body 32 toward the first inner wall surface 11a. This prevents the perforated body 32 from falling between the support bodies 31 and widens the flow path between the support bodies 31 on the frame 10 side. As a result, the transmittance increases, and the maximum heat transfer capacity becomes larger.

[0080] The arrangement of the support bodies 31 is not particularly limited, but it is preferable to arrange them equally in a specified area, and more preferably to arrange them equally as a whole, for example, to arrange the center-to-center distance (spacing) of the support bodies 31 to be constant.

[0081] Center-to-center distance of support 31 ( Figure 4 A or Figure 4 B in P 31 The length shown is, for example, 60 μm to 800 μm. The width of the support 31 (… Figure 4 A or Figure 4 B in W 31 The length shown is, for example, 20 μm to 500 μm. The height of the support 31 ( Figure 3 A in T 31 (The length shown) is, for example, between 10 μm and 100 μm.

[0082] The porous body 32 has a through hole 33 extending through the thickness direction Z. Within the through hole 33, the working medium 20 can move via capillary action. Preferably, the through hole 33, when viewed from the thickness direction Z, is located in the portion where the support body 31 is not present. The shape of the through hole 33 is not particularly limited, but the cross-section of the surface perpendicular to the thickness direction Z is preferably circular or elliptical.

[0083] The arrangement of the through holes 33 of the perforated body 32 is not particularly limited, but it is preferable to arrange them equally in a specified area, and more preferably to arrange them equally in the whole, for example, the center-to-center distance (spacing) of the through holes 33 of the perforated body 32 is constant.

[0084] The center-to-center distance of the through holes 33 in the perforated body 32 ( Figure 4 A or Figure 4 B in P 33 The length shown is, for example, 3 μm or more and 150 μm or less. The diameter of the end face on the second inner wall surface 12a side of the through hole 33 ( Figure 4 A or Figure 4 φ in B 33 The length shown is, for example, less than 100 μm. The thickness of the porous body 32 ( Figure 3 A in T 32 The length shown is, for example, 5 μm or more and 50 μm or less. Furthermore, the thickness of the porous body 32 refers to the thickness of the portion of the porous body 32 without the protrusion 34 described later.

[0085] A protrusion 34 is provided around the periphery of the through hole 33 in a direction close to the second inner wall surface 12a.

[0086] Figure 3 B is a schematic representation. Figure 3 A three-dimensional view of the shape of the protrusion of the core shown in Figure A.

[0087] The protrusion 34 has a first end portion 35 on the side of the first inner wall surface 11a and a second end portion 36 on the side of the second inner wall surface 12a.

[0088] exist Figure 3 In the example shown in B, the protrusion 34 is cylindrical. Thus, the protrusion 34 can be, for example, a cylindrical shape with a flat second end 36. In this case, the protrusion 34 can be a square cylinder, or a shape such as a frustum or pyramid with an internal cavity.

[0089] Figure 5 It is a schematic representation of the view from the side of the perforated body. Figure 3 A top view of the core shown in Figure A, including the through-hole, the protrusion, and the steam flow near the protrusion.

[0090] The working medium 20, which evaporates at the heat source HS, flows in a vapor state in the space between the porous body 32 and the second inner wall surface 12a in a direction away from the heat source HS. Figure 5 As shown, if a protrusion 34 is provided around the periphery of the through hole 33 in a direction close to the second inner wall surface 12a, the steam flowing in the space between the perforated body 32 and the second inner wall surface 12a will flow around the outer periphery of the protrusion 34. Therefore, direct contact between the steam flow and the liquid surface of the working medium 20 within the through hole 33 can be prevented. Therefore, the effect of steam flowing in the opposite direction to the capillary force of the core 30, the so-called backflow, can be reduced. Therefore, the maximum heat transfer capacity of the heat spreader 1 can be increased.

[0091] The protrusion 34 is preferably disposed on the entire periphery of the through hole 33. The protrusion 34 may also be disposed on only a portion of the periphery of the through hole 33.

[0092] The protrusion 34 may be provided on the periphery of all the through holes 33 in the porous body 32, or it may be provided only on the periphery of a portion of the through holes 33 in the porous body 32. When the protrusion 34 is provided only on the periphery of a portion of the through holes 33 in the porous body 32, it is preferable to provide the protrusion 34 on the periphery other than the through holes 33 located directly above the heat source HS.

[0093] The through hole 33 and the protrusion 34 can be manufactured, for example, by punching the metal constituting the hole body 32 using a stamping process. In the stamping process, the formation and shape of the protrusion can be adjusted by appropriately adjusting the punching depth, etc. Furthermore, the punching depth refers, for example, to the extent to which the punch is pressed in the punching direction when punching with a punch.

[0094] The dimensions of the protrusion 34 are not particularly limited. For example, the height of the protrusion 34 can be larger than the diameter of the through hole 33, the height of the protrusion 34 can be smaller than the diameter of the through hole 33, or the height of the protrusion 34 can be the same as the diameter of the through hole 33. Furthermore, in Figure 3 A and Figure 3 In the protrusion 34 of B, the height of the protrusion 34 refers to the distance in the thickness direction Z between the first end 35 and the second end 36.

[0095] Figure 3 The C is schematically represented. Figure 3 A perspective view of another example of the shape of the protrusion of the core shown in A.

[0096] exist Figure 3 In the convex portion 34 shown in C, the second end portion 36 is not flat, but has irregularities. Furthermore, when the second end portion 36 has irregularities, the height of the convex portion 34 refers to the maximum distance in the thickness direction Z between the first end portion 35 and the second end portion 36.

[0097] Figure 6 A is an enlarged cross-sectional view schematically representing a first modified example of the convex portion. Figure 6 B is a schematic representation. Figure 6 A three-dimensional view of the shape of the convex part shown in Figure A.

[0098] Figure 6 A and Figure 6 The protrusion 34a shown in Figure B has a first end portion 35a on the side of the first inner wall surface 11a and a second end portion 36a on the side of the second inner wall surface 12a. Viewed in the thickness direction Z, the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36a is smaller than the cross-sectional area of ​​the region enclosed by the inner wall of the first end portion 35a. Since the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36a is smaller than that of the region enclosed by the inner wall of the first end portion 35a, direct contact between the steam flow and the liquid surface of the working medium 20 within the through hole 33 can be further prevented. This further reduces the effect of backflow, thus further increasing the maximum heat transfer capacity of the heat spreader 1.

[0099] In the protrusion 34a, viewed from the thickness direction Z, the inner wall of the second end 36a is located further inward than the inner wall of the first end 35a. When viewed from the thickness direction Z, if the inner wall of the second end 36a is located further inward than the inner wall of the first end 35a, direct contact between the steam flow and the liquid surface of the working medium 20 within the through hole 33 can be further prevented. This further reduces the effect of backflow, thus further increasing the maximum heat transfer capacity of the heat spreader 1.

[0100] In a cross-section along the thickness direction Z, the protrusion 34a has a conical shape in which the distance between the outer walls of the protrusion 34a narrows as it approaches the second inner wall surface 12a. If the protrusion 34a has this conical shape in a cross-section along the thickness direction Z, the steam flowing in the space between the perforated body 32 and the second inner wall surface 12a can not only flow around the protrusion 34a, but also flow towards the second inner wall surface 12a along the outer wall surface of the protrusion 34a in a cross-section along the thickness direction Z. Therefore, in a cross-section along the thickness direction Z, compared to a protrusion 34a without the conical shape in which the distance between the outer walls of the protrusion 34a narrows as it approaches the second inner wall surface 12a, the flow path of the steam contacting the protrusion 34a can be increased. This helps to suppress the decrease in the thermal conductivity of the heat spreader 1.

[0101] The protrusion 34a is located on the side of the second inner wall surface 12a in the cross section along the thickness direction Z (in Figure 6 The shape protruding from the upper side (A in the diagram). In other words, the protrusion 34a is, in the cross section along the thickness direction Z, relative to the line segment connecting the first end 35a and the second end 36a, protruding towards the second inner wall surface 12a (in the section). Figure 6 The top of A is curved.

[0102] Figure 7 A is an enlarged cross-sectional view schematically representing a second variant of the convex portion. Figure 7 B is a schematic representation. Figure 7 A three-dimensional view of the shape of the convex part shown in Figure A.

[0103] Figure 7 A and Figure 7 The protrusion 34b shown in Figure B has a first end portion 35b on the side of the first inner wall surface 11a and a second end portion 36b on the side of the second inner wall surface 12a. In a cross-section along the thickness direction Z, the protrusion 34b has a tapered shape in which the distance between the outer walls of the protrusion 34b narrows as it approaches the second inner wall surface 12a. The protrusion 34b is located in a cross-section along the thickness direction Z towards the first inner wall surface 11a (in... Figure 7 The shape protruding from the lower side (A in the diagram). In other words, the protrusion 34b is, in the cross section along the thickness direction Z, relative to the line segment connecting the first end 35b and the second end 36b, towards the first inner wall surface 11a (in the section). Figure 7 The shape is curved (as shown in section A, the lower side). If, like the protrusion 34b, it is in the section along the thickness direction Z towards the first inner wall surface 11a (in... Figure 7 The shape protruding from the lower side of A is similar to the shape protruding towards the second inner wall surface 12a (in Figure 6 Compared to the convex portion 34a (with the upper side in section A), the outer wall surface of the portion at the first end 35b of the convex portion 34b has a gentler inclination. Therefore, when vapor flowing in the space between the perforated body 32 and the second inner wall surface 12a comes into contact with the portion at the first end 35b of the convex portion 34b, it flows more easily towards the second inner wall surface 12a in the cross section along the thickness direction Z, in a manner that follows the outer wall surface of the convex portion 34a. This further suppresses the decrease in the thermal conductivity of the heat spreader 1.

[0104] Figure 8-1 A is a partially enlarged cross-sectional view schematically representing a third variation of the convex portion. Figure 8-1 B is a schematic representation. Figure 8-1 A three-dimensional view of the shape of the convex part shown in Figure A.

[0105] Figure 8-1 A and Figure 8-1 The protrusion 34c shown in Figure B has a first end portion 35c on the side of the first inner wall surface 11a and a second end portion 36c on the side of the second inner wall surface 12a. Viewed from the thickness direction Z, the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36c of the protrusion 34c is smaller than the cross-sectional area of ​​the region enclosed by the inner wall of the first end portion 35c. The protrusion 34c has a cover portion 37 at the second end portion 36c that narrows the opening of the protrusion 34c. In the protrusion 34c, when viewed from the thickness direction Z, compared to the protrusion 34b where the cover portion 37 is absent at the second end portion 36c, the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36c is narrower. If the protrusion 34c has a cover portion 37 at the second end portion 36c that narrows the opening of the protrusion 34c, it is possible to further prevent the steam flow from directly contacting the liquid surface of the working medium 20 within the through hole 33. This further reduces the effect of backflow, and thus further increases the maximum heat transfer capacity of the heat exchanger 1.

[0106] The cover portion 37 that narrows the opening of the protrusion 34c can be formed, for example, by stamping the second end portion 36c. The size or shape of the cover portion 37 that narrows the opening of the protrusion 34c is not particularly limited, as long as the opening on the second end portion 36c side of the protrusion 34c is narrowed. The cover portion 37 that narrows the opening of the protrusion 34c is preferably a flat surface. The cover portion 37 that narrows the opening of the protrusion 34c is preferably a flat surface perpendicular to the thickness direction Z. The cover portion 37 that narrows the opening of the protrusion 34c may also be partially or entirely curved. The cover portion 37 that narrows the opening of the protrusion 34c may also have an uneven surface. The thickness of the cover portion 37 that narrows the opening of the protrusion 34c may be the same as or different from the thickness of the protrusion 34c.

[0107] exist Figure 8-1 A and Figure 8-1In B, the cover portion 37 is integrally disposed at the second end portion 36c. Figure 8-1 A and Figure 8-1 In B, the center of the periphery of the through hole 33 at the first end 35c coincides with the center of the periphery of the through hole 33 at the second end 36c.

[0108] Figure 8-2 A is a schematic representation. Figure 8-1 Another example of a convex part shown in A is an enlarged partial cross-sectional view. Figure 8-2 B is a schematic representation. Figure 8-2 A three-dimensional view of the shape of the convex part shown in Figure A.

[0109] exist Figure 8-2 A and Figure 8-2 In B, a cover 37 is provided only on a portion of the second end 36c. Figure 8-2 In A, a cover 37 is provided only on the right side of the protrusion 34c, and no cover 37 is provided on the left side of the protrusion 34c. Figure 8-2 A and Figure 8-2 In B, the center of the periphery of the through hole 33 at the first end 35c is not the same as the center of the periphery of the through hole 33 at the second end 36c.

[0110] Figure 8-3 A is a schematic representation. Figure 8-1 Another example of a convex part shown in A is an enlarged partial cross-sectional view. Figure 8-3 B is a schematic representation. Figure 8-3 A three-dimensional view of the shape of the convex part shown in Figure A.

[0111] exist Figure 8-3 A and Figure 8-3 In the protrusion 34c shown in Figure B, a cover 37 is provided only on a portion of the second end 36c. Figure 8-3 In A, a cover 37 is provided only on the right side of the protrusion 34c, and no cover 37 is provided on the left side of the protrusion 34c. Figure 8-3 In B, a cover portion 37 with a generally circular cross-section is provided as a part of the second end 36c. Figure 8-1 A, Figure 8-1 B Figure 8-2 A and Figure 8-2 In section B, the cover portion 37 is a flat surface perpendicular to the thickness direction Z, but... Figure 8-3 A and Figure 8-3 In B, the cover 37 is configured to face the second inner wall surface 12a. Figure 8-3 (Extends from the upper side of A). In Figure 8-3 A and Figure 8-3 In B, the cover 37 is a flat surface, but the cover 37 can also be a curved surface.

[0112] Figure 9 This is an enlarged cross-sectional view schematically representing a fourth modified example of the convex portion.

[0113] Figure 9 The convex portion 34d shown has a first end portion 35d on the side of the first inner wall surface 11a and a second end portion 36d on the side of the second inner wall surface 12a. Viewed from the thickness direction Z, the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36d of the convex portion 34d is larger than the cross-sectional area of ​​the region enclosed by the inner wall of the first end portion 35d.

[0114] In the protrusion 34d, when viewed from the thickness direction Z, the inner wall of the second end 36d is located on the outer side than the inner wall of the first end 35d.

[0115] Figure 10 This is an enlarged cross-sectional view schematically representing a fifth variation of the convex portion.

[0116] Figure 10 The convex portion 34e shown has a first end portion 35e on the side of the first inner wall surface 11a and a second end portion 36e on the side of the second inner wall surface 12a. Viewed in the thickness direction Z, the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36e of the convex portion 34e is larger than the cross-sectional area of ​​the region enclosed by the inner wall of the first end portion 35e. The convex portion 34e has a cover portion 37 at the second end portion 36e that narrows the opening of the convex portion 34e. In the convex portion 34e, when viewed in the thickness direction Z, compared to the convex portion 34d without the cover portion 37 at the second end portion 36e, the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36e is narrower. If the convex portion 34e has a cover portion 37 at the second end portion 36e that narrows the opening of the convex portion 34e, it is possible to further prevent the steam flow from directly contacting the liquid surface of the working medium 20 within the through hole 33. This further reduces the effect of backflow, and thus further increases the maximum heat transfer capacity of the heat exchanger 1.

[0117] The cover portion 37 that narrows the opening of the protrusion 34e can be formed, for example, by stamping the second end portion 36e. The size or shape of the cover portion 37 that narrows the opening of the protrusion 34e is not particularly limited, as long as the opening on the second end portion 36e side of the protrusion 34e is narrowed. The cover portion 37 that narrows the opening of the protrusion 34e is preferably a flat surface. The cover portion 37 that narrows the opening of the protrusion 34e is preferably a flat surface perpendicular to the thickness direction Z. The cover portion 37 that narrows the opening of the protrusion 34e may also be partially or entirely curved. The cover portion 37 that narrows the opening of the protrusion 34e may also have an uneven surface. The thickness of the cover portion 37 that narrows the opening of the protrusion 34e may be the same as or different from the thickness of the protrusion 34e.

[0118] Figure 11It is a schematically enlarged cross-sectional view of a first modified example of the core.

[0119] exist Figure 11 In the core 30A shown, a portion of the metal foil is bent and recessed, for example, by stamping, thereby forming a support 31 in the recessed portion. Since a vapor space is formed in the recessed portion of the support 31, the thermal conductivity is improved. (Not limited to...) Figure 11 In the example shown, when the metal foil is stamped, depending on the stamping process, a through hole may be formed in the recessed portion when a part of the metal foil is bent.

[0120] The thickness of the metal foil is preferably constant before stamping or other processing. However, the metal foil may become thinner in the bent portions. As described above, in the core 30A, the thickness of the support 31 is preferably the same as or smaller than the thickness of the perforated body 32.

[0121] The core 30A is preferably formed by stamping the support 31 and the through hole 33 and protrusion 34 together.

[0122] In the core 30A, the thickness of the protrusion 34 can be the same as the thickness of the support 31. In the core 30A, the thickness of the protrusion 34 can be the same as the thickness of the perforated body 32. For example... Figure 11 As shown, in the core 30A, the thickness of the support 31, the thickness of the perforated body 32, and the thickness of the protrusion 34 can be constant.

[0123] In the core 30A, the thickness of the protrusion 34 may differ from the thickness of the support 31. In the core 30A, the thickness of the protrusion 34 may also differ from the thickness of the perforated body 32.

[0124] Figure 12 It is a schematic representation Figure 11 The enlarged cross-sectional view of a first modified example of the protrusion in the core shown.

[0125] Figure 12 The convex portion 34b shown has the same Figure 7 A and Figure 7 The protrusion 34b shown in Figure B has the same shape. The protrusion 34b has a first end portion 35b on the side of the first inner wall surface 11a and a second end portion 36b on the side of the second inner wall surface 12a. In a cross-section along the thickness direction Z, the protrusion 34b has a tapered shape in which the distance between the outer walls of the protrusion 34b narrows as it approaches the second inner wall surface 12a. The protrusion 34b is in a cross-section along the thickness direction Z, towards the first inner wall surface 11a (in... Figure 12The shape protrudes from the lower side (in the middle). In other words, the protrusion 34b is, in a cross-section along the thickness direction Z, relative to the line segment connecting the first end 35b and the second end 36b, towards the first inner wall surface 11a (in the middle). Figure 12 The middle part is the curved shape (the bottom part).

[0126] The thickness of the protrusion 34b can be the same as or different from the thickness of the support 31. The thickness of the protrusion 34b can be the same as or different from the thickness of the perforated body 32.

[0127] Figure 13 It is a schematic representation Figure 11 The enlarged partial cross-sectional view of the second modified example of the protrusion in the core shown.

[0128] Figure 13 The convex portion 34c shown has the same Figure 8-1 A and Figure 8-1 The protrusion 34c shown in Figure B has the same shape. The protrusion 34c has a first end portion 35c on the side of the first inner wall surface 11a and a second end portion 36c on the side of the second inner wall surface 12a. Viewed in the thickness direction Z, the cross-sectional area of ​​the region enclosed by the inner wall of the second end portion 36c of the protrusion 34c is smaller than the cross-sectional area of ​​the region enclosed by the inner wall of the first end portion 35c. The protrusion 34c has a cover portion 37 at the second end portion 36c that narrows the opening of the protrusion 34c.

[0129] The thickness of the protrusion 34c can be the same as or different from the thickness of the support 31. The thickness of the protrusion 34c can be the same as or different from the thickness of the perforated body 32. The thickness of the cover 37, which narrows the opening of the protrusion 34c, can be the same as or different from the thickness of the support 31. The thickness of the cover 37, which narrows the opening of the protrusion 34c, can be the same as or different from the thickness of the perforated body 32.

[0130] Figure 11 The convex portion 34 shown can also be... Figure 6 A and Figure 6 The convex part 34a shown in B, Figure 9 The convex part 34d shown or Figure 10 The convex part 34e shown has the same shape.

[0131] Figure 14 This is an enlarged cross-sectional view schematically representing a second variant of the core.

[0132] exist Figure 14In the core 30B shown, the porous body 32 is made of a different material than the support 31. The material constituting the support 31 is not particularly limited; examples include resin, metal, ceramic, or mixtures or laminates thereof. The material constituting the porous body 32 is also not particularly limited; examples include resin, metal, ceramic, or mixtures or laminates thereof. The preferred material constituting the porous body 32 is metal.

[0133] Figure 14 The convex portion 34 shown can also be... Figure 6 A and Figure 6 The convex part 34a shown in B, Figure 7 A and Figure 7 The convex portion 34b shown in B, Figure 8-1 A and Figure 8-1 The convex portion 34c shown in B, Figure 8-2 A and Figure 8-2 The convex portion 34c shown in B, Figure 8-3 A and Figure 8-3 The convex portion 34c shown in B, Figure 9 The convex part 34d shown or Figure 10 The convex part 34e shown has the same shape.

[0134] Figure 15 This is a schematic top view representing a third modified example of the core. Furthermore, Figure 15 This is a top view of the core as seen from the support side.

[0135] exist Figure 15 In the core 30C shown, the support 31 includes multiple track-shaped components. By maintaining the working medium 20 in liquid phase between the track-shaped components, the heat transfer performance of the heat spreader 1 can be improved. Here, "track-shaped" refers to a shape in which the ratio of the length of the long side of the bottom surface to the length of the short side of the bottom surface is more than 5 times.

[0136] The cross-sectional shape of the track-like component perpendicular to the direction of extension is not particularly limited. Examples include polygons such as quadrilaterals, semicircles, semi-ellipses, and shapes formed by combining them.

[0137] The track-shaped component only needs to be relatively higher than its surroundings. Therefore, in addition to the portion protruding from the first inner wall surface 11a, the track-shaped component also includes a portion whose height is relatively increased due to the groove formed in the first inner wall surface 11a.

[0138] In addition, core 30C is not limited to Figure 15 The disclosed shape can also be used in a partial configuration rather than as part of the interior space. For example, a track-like support 31 can be formed along the outer periphery of the interior space, and a perforated body 32 with a shape along the outer periphery can be disposed thereon.

[0139] like Figure 2 As shown, a support column 40 that contacts the second inner wall surface 12a can also be arranged in the internal space of the frame 10. By arranging the support column 40 in the internal space of the frame 10, the frame 10 and the core 30 can be supported.

[0140] The material constituting the support column 40 is not particularly limited, and examples include resin, metal, ceramic, or mixtures or laminates thereof. Alternatively, the support column 40 can be integral with the frame 10, for example, by etching the second inner wall surface 12a of the frame 10.

[0141] The shape of the support column 40 is not particularly limited as long as it can support the frame 10 and the core 30. The shape of the cross section of the support column 40 perpendicular to the height direction can be, for example, a rectangle, a polygon, a circle, an ellipse, etc.

[0142] The height of the support column 40 within a heat spreader can be the same or different.

[0143] exist Figure 2 In the cross-section shown, the width of the support column 40 is not particularly limited as long as it provides sufficient strength to suppress deformation of the frame 10. However, the equivalent circle diameter of the section perpendicular to the height direction at the end of the support column 40 is, for example, 100 μm to 2000 μm, preferably 300 μm to 1000 μm. By increasing the equivalent circle diameter of the support column 40, deformation of the frame 10 can be further suppressed. On the other hand, by decreasing the equivalent circle diameter of the support column 40, a larger space can be ensured for the movement of steam for the working medium 20.

[0144] The arrangement of the supports 40 is not particularly limited, but it is preferable that they are evenly distributed in a specified area, and more preferably evenly distributed throughout the entire area, for example, by arranging the supports 40 with a constant distance between them. By evenly distributing the supports 40, uniform strength can be ensured throughout the heat spreader 1.

[0145] Figure 16 This is a cross-sectional view schematically representing a first modified example of a heat diffusion device.

[0146] exist Figure 16 In the vapor chamber (heat diffusion device) 1A shown, the support 31 and the first sheet 11 of the frame 10 are integrally formed. In the vapor chamber 1A, the first sheet 11 and the support 31 can be fabricated, for example, by etching technology, multilayer coating-based printing technology, or other multilayer technologies. Figure 16As shown, the perforated body 32 is preferably made of a different material than the support body 31. In the heat spreader (heat diffusion device) 1A, the perforated body 32 may also be made of the same material as the support body 31 and the first sheet 11 of the frame 10, and the perforated body 32 may also be integrally formed with the support body 31 and the first sheet 11 of the frame 10.

[0147] Figure 17 This is a cross-sectional view schematically representing a second modified example of a heat diffusion device.

[0148] exist Figure 17 In the heat spreader (heat diffusion device) 1B shown, for example, a portion of the first inner wall surface 11a of the frame 10 is bent and recessed by stamping or the like, thereby forming a support 31 in the recessed portion.

[0149] The heat diffusion device of this utility model is not limited to the above-described embodiments. Various applications and modifications can be applied to the structure and manufacturing conditions of the heat diffusion device within the scope of this utility model.

[0150] Figure 18 Viewed from the side of the perforated body Figure 3 A top view of the first modified example of the core shown in Figure A. Figure 19 yes Figure 18 The core shown is a cross-sectional view along line AA.

[0151] exist Figure 19 In the core 30D shown, in the cross-section along the thickness direction Z, the protrusions 34 are curved relative to each other, and there are no flat portions. Furthermore, Figure 19 This is a cross-sectional view through the through hole 33. However, in the cross-section along the thickness direction Z that does not pass through the through hole 33, there may or may not be flat portions between the protrusions 34. In addition, in the core 30D, the perforated body 32 may be a curved surface as a whole, without any flat portions.

[0152] Figure 20 It is used for explanation Figure 12 A diagram showing the definition of the protrusions in the core. Figure 20 In addition to adding lines L1 and L2, it is related to... Figure 12 Same diagram.

[0153] In this specification, a protrusion is defined as the portion between straight lines L1 and L2, as shown below, in a cross-section along the thickness direction Z. Furthermore, in the case of multiple protrusions, straight lines L1 and L2 are defined for each individual protrusion. Figure 20 As shown, in the cross-section along the thickness direction Z, on both sides of the through hole ( Figure 20When there are convex parts on both the right and left sides, straight lines L1 and L2 are defined for each convex part. In the definition of convex parts described below, the surface perpendicular to the thickness direction Z (XY surface) is called the reference surface. Examples are given below. Figure 20 Taking the core 30A shown as an example, the lines L1 and L2 will be explained.

[0154] (1) Setting the line L2

[0155] First, the point closest to the second inner wall surface 12a side in the second end 36b of the protrusion 34b on the periphery of the second inner wall surface 12a side of the through hole 33 ( Figure 20 Let point P2 be the reference plane and a straight line parallel to it be L2.

[0156] (2) Setting of line L1

[0157] Next, line L1 is set as follows.

[0158] (2-1) In the case where there is a portion parallel to the reference plane

[0159] The point that is closest to the periphery of the second inner wall surface 12a side of the through hole 33 in the portion of the core 30A side parallel to the reference plane on the surface of the protrusion 34b between each other on the second inner wall surface 12a side of the core 30A is ( Figure 20 Let point P1 be a reference point, and let the line parallel to the reference plane be L1.

[0160] Without setting line L1 according to the definition in (2-1), line L1 is set as follows.

[0161] Figure 21 It is used for explanation Figure 19 A diagram showing the definition of the protrusions in the core.

[0162] (2-2) In the case where there is a portion where the tangent is parallel to the reference plane

[0163] The point that is closest to the periphery of the second inner wall surface 12a side of the through hole 33 is the portion of the surface on which the tangent drawn between the protrusions 34 on the second inner wall surface 12a side of the core 30D is parallel to the reference plane. Figure 21 Let point P1 be a reference point, and let the line parallel to the reference plane be L1.

[0164] exist Figure 21 In the core 30D shown, the protrusions 34 are curved relative to each other, and there are no flat parts, but the part on the straight line L1 becomes the first end 35.

[0165] Without defining line L1 according to the definitions in (2-1) and (2-2), line L1 is defined as follows.

[0166] (2-3) In the case of inflection points or bending points

[0167] The point on the surface of the core 30A between the protrusions 34 that has the smallest distance from the periphery of the second inner wall surface 12a side of the through hole 33, among the inflection points or bending points, is designated as L1, and is a straight line parallel to the reference plane. An inflection point is a point where the convexity changes on a curve, i.e., a point where the convexity changes from downward to upward, or vice versa. A bending point is a non-differentiable point, such as the intersection of straight lines with different slopes, or the intersection of a straight line and a curve.

[0168] (3) Supplement to the definition of a convex part

[0169] The following is a supplementary explanation of the definition of a convex part. Examples are given in the following explanation. Figure 20 The core 30A shown is used as an example for explanation, but the definitions described below also apply. Figure 21 The core shown is 30D.

[0170] (3-1) Supplement 1

[0171] Even if the conditions described in (2-1), (2-2) or (2-3) are met, the portion of the core 30A that contacts the first inner wall surface 11a, i.e. the portion of the support 31 that contacts the first inner wall surface 11a, is not considered as the portion parallel to the reference plane in (2-1), the portion with the tangent parallel to the reference plane in (2-2), or the portion with an inflection point or bending point in (2-3).

[0172] (3-2) Supplement 2

[0173] In core 30A, such as Figure 13 As shown, when the protrusion 34c has a cover 37, even if the conditions described in (2-1), (2-2) or (2-3) are met, the cover 37 is not considered as the part parallel to the reference plane in (2-1), the part with the tangent parallel to the reference plane in (2-2), or the part with an inflection point or bending point in (2-3).

[0174] (3-3) Supplement 3

[0175] In a cross-section along the thickness direction Z, the portion on the straight line L1 of the core 30A becomes the first end portion 35b. In the case of multiple portions on the straight line L1 of the core 30A, the portion including the point with the smallest distance from the periphery of the second inner wall surface 12a side of the through hole 33 becomes the first end portion 35b. The portion from this first end portion 35b to the second end portion 36b becomes the protrusion 34b.

[0176] In the heat diffusion device of this invention, the frame may have one evaporation section or multiple evaporation sections. That is, one heat source or multiple heat sources may be disposed on the outer wall surface of the frame. The number of evaporation sections and heat sources is not particularly limited.

[0177] In the heat diffusion device of this utility model, when the frame is composed of a first sheet and a second sheet, the first sheet and the second sheet can overlap with the same end or overlap with the ends staggered.

[0178] In the heat diffusion device of this invention, when the frame is composed of a first sheet and a second sheet, the materials constituting the first sheet and the second sheet can be different. For example, by using a high-strength material in the first sheet, the stress applied to the frame can be dispersed. Furthermore, by using different materials for the two sheets, one sheet can achieve one function, and the other sheet can achieve other functions. There are no particular limitations on the aforementioned functions; examples include heat conduction and electromagnetic wave shielding.

[0179] The heat dissipation device of this invention can be incorporated into electronic devices for heat dissipation purposes. Therefore, electronic devices equipped with the heat dissipation device of this invention are also considered part of this invention. Examples of electronic devices that embody this invention include smartphones, tablets, laptops, game consoles, and wearable devices. As described above, the heat dissipation device of this invention operates independently without external power, utilizing the latent heat of vaporization and condensation of the working medium to dissipate heat in a two-dimensional and high-speed manner. Therefore, electronic devices equipped with the heat dissipation device of this invention can effectively dissipate heat within the limited space inside the electronic device.

[0180] Industrial availability

[0181] This heat dissipation device can be widely used in portable information terminals and other fields. For example, it can be used to reduce the temperature of heat sources such as CPUs, extend the service life of electronic devices, and can be used in smartphones, tablets, laptops, etc.

[0182] Explanation of reference numerals in the attached figures

[0183] 1, 1A, 1B… Heat spreader (heat diffusion device); 10… Frame; 11… First sheet; 11a… First inner wall surface; 12… Second sheet; 12a… Second inner wall surface; 20… Working medium; 30, 30A, 30B, 30C, 30D… Core; 31… Support; 32… Perforated body; 33… Through hole; 34, 34a, 34b, 34c, 34d, 34e… Protrusion; 35, 35a, 35b, 35c, 35d, 35e… First end; 36, 36a, 36b, 36c, 36d, 36e… Second end; 37… Cover; 40… Support; HS… Heat source; P 31 …the center-to-center distance of the supports; P 33 …the center-to-center distance of the through holes; T 31 …height of the support; T 32 …thickness of the porous body; W 31 …width of the support; X…width direction; Y…length direction; Z…thickness direction; φ 33 …the diameter of the end face of the second inner wall side of the through hole.

Claims

1. A thermal diffusion device, characterized by, Possessing: a frame body having a first inner wall surface and a second inner wall surface opposing each other in a thickness direction; a working medium enclosed in an internal space of the frame body; and a core body disposed in the internal space of the frame body, the core body includes a support body in contact with the first inner wall surface, and a porous body in contact with the support body, the porous body has a through-hole passing through in the thickness direction, the support body has a portion recessed, a protrusion is provided on a peripheral edge of the through-hole in a direction approaching the second inner wall surface.

2. The heat diffusion device according to claim 1, wherein the protrusion has a first end portion on the first inner wall surface side and a second end portion on the second inner wall surface side, a cross-sectional area of a region surrounded by an inner wall at the second end portion is smaller than a cross-sectional area of a region surrounded by an inner wall at the first end portion when viewed in the thickness direction.

3. The heat diffusion device according to claim 2, wherein an inner wall of the second end portion is located inward of an inner wall of the first end portion when viewed in the thickness direction.

4. The heat diffusion device according to claim 3, wherein the protrusion has a tapered shape in which a distance between outer walls of the protrusion narrows as it approaches the second inner wall surface in a cross section along the thickness direction.

5. The heat diffusion device according to claim 1, wherein the protrusion has a first end portion on the first inner wall surface side and a second end portion on the second inner wall surface side, a cross-sectional area of a region surrounded by an inner wall at the second end portion is larger than a cross-sectional area of a region surrounded by an inner wall at the first end portion when viewed in the thickness direction.

6. The heat diffusion device according to claim 5, wherein an inner wall of the second end portion is located outward of an inner wall of the first end portion when viewed in the thickness direction.

7. The heat diffusion device according to any one of claims 2 to 6, wherein the protrusion has a cover portion at the second end portion that narrows an opening of the protrusion.

8. The heat diffusion device according to any one of claims 1 to 6, wherein a thickness of the support body is the same as or smaller than a thickness of the porous body.

9. The heat diffusion device according to any one of claims 1 to 6, wherein the porous body is composed of the same material as the support body.

10. The heat diffusion device according to any one of claims 1 to 6, wherein the porous body is composed of a different material from the support body.

11. The heat diffusion device according to any one of claims 1 to 6, wherein the support body includes a plurality of columnar members.

12. The heat diffusion device according to any one of claims 1 to 6, wherein the support body includes a plurality of rail-like members.

13. The heat diffusion device according to any one of claims 1 to 6, wherein a through-hole having a capillary force is provided with respect to the through-hole.

14. The heat spreading device according to any one of claims 1 to 6, wherein the portion of the support body in which the recess is formed is formed by press working.

15. The heat spreading device according to claim 14, wherein the through hole and the protrusion are formed by press working.

16. The heat spreading device according to claim 15, wherein the core is formed by simultaneously performing the press working for forming the support body and the press working for forming the through hole and the protrusion.

17. An electronic device, comprising: the heat spreading device according to any one of claims 1 to 16. ​ ​ ​ ​

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