Heat dissipation structure, electronic device and manufacturing method thereof

Abstract

The invention provides a heat dissipation structure, an electronic device and a manufacturing method thereof, wherein the heat conduction performance between a heat-generating electric component and a heat dissipation body can be prevented from being reduced, and the surface of the electric component can be maintained in an appropriate state. The heat dissipation structure (60) is provided with: a metal mesh (64) that comes into contact with the surface of the die (46); and a heat receiving plate (72) that sandwiches the mesh (64) between the heat receiving plate (72) and the surface of the die (46). The mesh (64) is impregnated with a liquid metal (70) at least in a portion that comes into contact with the surface of the die (46), and the intersection (96) of the vertical and horizontal wires (90) is flattened in the thickness direction. The mesh (64) has a planar portion (90a) formed on the surface side of the wire (90) at the intersection point (96).

Description

Technical Field

[0001] The present invention relates to a heat dissipation structure of a heat-generating electrical component, an electronic device having the heat dissipation structure, and a method for manufacturing the same. Background Art

[0002] Semiconductor chips such as CPU and GPU are provided in portable information devices such as notebook PCs. CPU and GPU are in the form of a base chip which is a part mounted on a substrate and a rectangular bare chip provided on the surface of the base chip.

[0003] Semiconductor chips such as CPUs and GPUs are heat generating elements, and their power consumption (especially when under high load) requires heat dissipation. As a means of dissipating heat from the CPU and GPU, heat sinks such as heat spreaders, heat sinks, or heat sinks are sometimes used, and the heat is diffused by contacting the heat sink with the surface of the bare chip. In order to efficiently transfer heat, there are cases where a fluid such as liquid metal or thermally conductive grease is sandwiched between the bare chip and the heat sink (for example, Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2004-146819

[0005] Liquid metal has a higher thermal conductivity than thermal grease, and can effectively transfer heat from the bare chip to the heat sink. On the other hand, liquid metal has a higher fluidity than thermal grease. When carrying electronic devices, they are easily subjected to vibration and impact. Therefore, there is a concern that the liquid metal with fluidity may leak out from the gap between the bare chip and the heat sink due to repeated forces from the bare chip and the heat sink.

[0006] Liquid metals are sometimes mainly composed of gallium, which may react chemically with copper and solder. In addition, liquid metals are conductive, so if they leak out and come into contact with surrounding electrical components such as capacitors, they will cause a short circuit, so some countermeasures are needed.

[0007] Therefore, the inventors of the present application have studied the method of placing a metal mesh impregnated with liquid metal between a heat generating body such as a semiconductor chip and a heat sink such as a heat spreader to sandwich the metal mesh. The liquid metal impregnated in the metal mesh is maintained without leaking out.

[0008] However, in the metal mesh, since the wires are woven vertically and horizontally, the intersections of the wires become small protrusions, which may slightly damage the surface of the bare chip that contacts. Summary of the invention

[0009] The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat dissipation structure, an electronic device and a method for manufacturing the same that can prevent a decrease in thermal conductivity between a heat-generating electrical component and a heat sink and can maintain the surface of the electrical component in a suitable state.

[0010] In order to solve the above-mentioned problems and achieve the purpose, the heat dissipation structure involved in the first mode of the present invention is a heat dissipation structure of a heat-generating electrical component, which comprises: a metal mesh abutting the surface of the above-mentioned electrical component; and a heat sink clamping the above-mentioned metal mesh between the surface of the above-mentioned electrical component, the above-mentioned metal mesh is impregnated with a thermally conductive fluid at least in the portion abutting the surface of the above-mentioned electrical component, and the intersection of the vertical and horizontal wires is in a shape that is flattened in the thickness direction.

[0011] The electronic device involved in the second embodiment of the present invention is an electronic device with a heat-generating electrical component, which comprises: a metal mesh that abuts the surface of the above-mentioned electrical component; and a heat sink that clamps the above-mentioned metal mesh between the surface of the above-mentioned electrical component, and the above-mentioned metal mesh is impregnated with a thermally conductive fluid at least in the portion that abuts the surface of the above-mentioned electrical component, and the intersection of the vertical and horizontal wires is in a shape that is flattened in the thickness direction.

[0012] The manufacturing method of an electronic device involved in the third embodiment of the present invention is a manufacturing method of an electronic device having a heat-generating electrical component, which comprises: a step of stamping a metal mesh; a step of impregnating the metal mesh with a thermally conductive fluid; and a step of clamping the metal mesh between the surface of the electrical component and a heat sink.

[0013] According to the above aspect of the present invention, the reduction in thermal conductivity between the heat-generating electrical component and the radiator can be prevented, and the intersections of the wires are compressed in the thickness direction, so the surface of the electrical component can be maintained in a suitable state. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic plan view of an electronic device according to an embodiment when viewed from above.

[0015] Figure 2 It is a bottom view schematically showing the internal structure of the casing.

[0016] Figure 3 This is a schematic exploded perspective view of the CPU, heat-conducting structure, and sponge mounted on the motherboard.

[0017] Figure 4 This is an exploded perspective view of the heat dissipation structure.

[0018] Figure 5 This is a three-dimensional diagram of the heat dissipation structure.

[0019] Figure 6 It is a schematic cross-sectional side view of the heat dissipation structure.

[0020] Figure 7This is an exploded perspective view of the heat-conducting structure.

[0021] Figure 8 It is a cross-sectional view of the mesh and its surroundings.

[0022] Fig. 9 is an enlarged top view of the mesh.

[0023] Fig.10 is a cross-sectional view of a mesh blank.

[0024] Fig.11 It is a schematic diagram showing a state in which a mesh blank is rolled to produce a mesh.

[0025] Fig.12 This is a flowchart showing a part of a method for manufacturing an electronic device.

[0026] Fig.13 This is a three-dimensional view of the heat dissipation structure covered with a protective film.

[0027] Description of Reference Numerals

[0028] 10…electronic device; 14…housing; 22…cooling module; 24…motherboard (substrate); 30…CPU (electrical component); 36…heat spreader (heat sink); 38…heat pipe; 44…substrate; 46…bare chip (electrical component); 48…flange; 60…heat dissipation structure; 62…heat conductive structure; 64…mesh (metal mesh; 64a…heating element contact range portion; 64b…heating element non-contact range portion; 65…sponge; 66, 68…sheet material; 70…liquid metal (thermal conductive fluid); 72…heat receiving plate (heat sink); 74…adhesive material; 76…adhesive tape; 78…peeling paper; 80…protective film; 90…wire; 90a…plane portion; 92…mesh blank; 94…wire; 96…intersection. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the heat dissipation structure, electronic device, and method for manufacturing the same according to the present invention will be described in detail based on the accompanying drawings. However, the present invention is not limited to the embodiments.

[0030] Figure 1 1 is a schematic top view of an electronic device 10 according to an embodiment of the present invention as viewed from above. Figure 1 As shown, the electronic device 10 is a clamshell notebook PC in which a display housing 12 and a housing 14 are connected by a hinge 16 so as to be relatively rotatable, and is called a so-called mobile workstation. The electronic device involved in the present invention may be a desktop PC, a tablet PC, a mobile phone, a smart phone, or a game console, etc., in addition to a notebook PC.

[0031] The display housing 12 is a thin and flat box. The display housing 12 is provided with a display 18. The display 18 is composed of, for example, organic EL (OLED: Organic Light Emitting Diode) or liquid crystal.

[0032] Next, with respect to the housing 14 and the elements mounted on the housing 14, the housings 12 and 14 are arranged as follows. Figure 1 The illustration shows an opened state, and based on the visual confirmation posture of the display 18, the near front side is referred to as the front, the inner side is referred to as the rear, the width direction is referred to as the left and right, and the height direction (the thickness direction of the shell 14) is referred to as the top and bottom for explanation.

[0033] The housing 14 is a thin and flat box. The housing 14 is composed of a cover part 14A forming the upper surface and the surrounding sides and a cover part 14B forming the lower surface. The upper cover part 14A has a roughly bathtub shape with an open lower surface. The lower cover part 14B has a roughly flat plate shape and serves as a cover body that closes the lower surface opening of the cover part 14A. The cover parts 14A and 14B overlap in the thickness direction and are connected to each other so that they can be loaded and unloaded. A keyboard 20 and a touch pad 21 are provided on the upper surface of the housing 14. The rear end of the housing 14 is connected to the display housing 12 using a hinge 16.

[0034] Figure 2 FIG. 1 is a bottom view schematically showing the internal structure of the housing 14. Figure 2 In the embodiment, the cover member 14B on the lower surface is omitted to expose the interior. Figure 2 As shown, a cooling module 22, a motherboard (substrate) 24, and a battery device 26 are provided inside the housing 14. Various electronic components, mechanical components, and the like are also provided inside the housing 14.

[0035] The motherboard 24 is the main board of the electronic device 10. The motherboard 24 is arranged at the rear of the housing 14 and extends in the left-right direction. The motherboard 24 is a printed circuit board on which various electronic components such as a communication module, a memory, and connection terminals are installed in addition to the CPU (Central Processing Unit) 30 and the GPU (Graphics Processing Unit) 31. The motherboard 24 is arranged under the keyboard 20 and is screwed to the back of the keyboard 20 and the inner surface of the cover part 14A. The upper surface of the motherboard 24 becomes the assembly surface relative to the cover part 14A, and the lower surface becomes the installation surface of the CPU 30 and the like. The CPU 30 performs calculations related to the main control and processing of the electronic device 10. The GPU 31 performs calculations required for image drawing such as 3D graphics. The CPU 30 and the GPU 31 are arranged side by side in the approximate center of the installation surface of the motherboard 24.

[0036] The battery device 26 is a rechargeable battery that serves as a power source for the electronic device 10. The battery device 26 is disposed in front of the motherboard 24 and extends leftward and rightward along the front end of the housing 14.

[0037] The CPU 30 and GPU 31 are heat generating elements with the largest level of heat among the electronic components mounted in the housing 14. Therefore, the cooling module 22 absorbs and diffuses the heat generated by the CPU 30 and GPU 31 and discharges it to the outside of the housing 14. The cooling module 22 is stacked on the lower surface of the motherboard 24.

[0038] The cooling module 22 includes a heat spreader (heat sink) 36 , two heat pipes 38 , 38 , a pair of left and right cooling fins 40 , 41 , and a pair of left and right air-sending fans 42 , 43 .

[0039] The heat spreader 36 is a plate-type heat transfer device. The heat spreader 36 is a component that forms a closed space between two thin metal plates and seals a working fluid in the closed space. The metal plates are formed of a metal with high thermal conductivity such as aluminum, copper, or stainless steel. The closed space becomes a flow path for the sealed working fluid to undergo a phase change and flow. Examples of the working fluid include water, a Freon substitute, acetone, or butane. A liquid wick that utilizes capillary action to transport the condensed working fluid is provided in the closed space. The liquid wick is formed of a porous body such as a mesh obtained by weaving metal fine wires into a flocculent state, a micro-flow path, etc. The heat spreader 36 is reinforced by a frame 45 (see Figure 4 ).

[0040] Heat pipes 38, 38 are tubular heat transport equipment. In the present embodiment, two heat pipes 38 are used in parallel in a group of two in the front and back, but one or more heat pipes may be used. The heat pipe 38 is a component formed by flattening a metal pipe into a thin and flat shape with an elliptical cross-section, and a working fluid is sealed in a closed space formed in the metal pipe. The metal pipe is formed of a metal with high thermal conductivity such as aluminum, copper or stainless steel. The closed space becomes a flow path for the sealed working fluid to undergo a phase change and flow. As working fluids, for example, water, freon substitutes, acetone or butane can be exemplified. A liquid wick is provided in the closed space for conveying the condensed working fluid using capillary action. The liquid wick is formed of a porous body such as a mesh obtained by weaving metal fine wires into a flocculent state, a micro-flow path, etc.

[0041] The cooling fins 40 and 41 on the left side are structured by arranging a plurality of plate-shaped fins at equal intervals in the left-right direction on the surface of the plate. Each fin stands up in the up-down direction and extends in the front-back direction. A gap is formed between adjacent fins for the air delivered from the air supply fans 42 and 43 to pass through.

[0042] Figure 3It is a schematic exploded perspective view of the CPU 30 , the heat conductive structure 62 , and the sponge 65 mounted on the motherboard 24 .

[0043] The CPU 30 includes a substrate 44 and a bare chip 46. The substrate 44 is a thin plate-shaped portion mounted on the motherboard 24, and is a rectangular shape that is long in the left-right direction when viewed from above. The bare chip 46 is a portion including an arithmetic circuit, and is provided so as to protrude slightly from the surface of the substrate 44. The bare chip 46 is a rectangular shape that is slightly long in the left-right direction when viewed from above, and is provided approximately in the center of the surface of the substrate 44. The CPU 30 is one of the components that generate the most heat in the electronic device 10, and the bare chip 46 generates particularly much heat.

[0044] A flange 48 for reinforcement is erected on the edges around the substrate 44. The flange 48 is slightly lower than the bare chip 46. The gap between the bare chip 46 and the flange 48 is slightly wider in the left-right direction, but narrows in the front-back direction. A small component 50 such as a capacitor is provided on the surface of the substrate 44. The component 50 is covered with an insulating material 52. The insulating material 52 is, for example, a UV-curable coating material and is formed in a film shape. After the coating material is applied in a manner covering the component 50, it is cured by being irradiated with ultraviolet rays to form the insulating material 52. According to the UV-curable coating material, the insulating material 52 is easily formed. The insulating material 52 can also be other insulating adhesives, etc. The liquid metal 70 described later basically does not contact the component 50, but if the component 50 is covered with the insulating material 52, the reliability is further improved.

[0045] Next, the heat dissipation structure 60 according to the present embodiment will be described. Figure 4 It is an exploded perspective view of the heat dissipation structure 60 . Figure 5 It is a perspective view of the heat dissipation structure 60 . Figure 6 4 is a schematic cross-sectional side view of the heat dissipation structure 60 . Figure 7 It is an exploded perspective view of the thermally conductive structure 62 .

[0046] The heat dissipation structure 60 is used to dissipate heat from the CPU (electrical component, semiconductor chip) 30, particularly the bare die (electrical component) 46, and includes a heat conductive structure 62 and a sponge 65. The heat spreader 36 constitutes a part of the heat dissipation structure 60.

[0047] The heat-conducting structure 62 includes a mesh (metal mesh) 64 and sheets 66 and 68 that sandwich both ends of the mesh 64 in the left and right directions. The heat-conducting structure 62 is small and light. The mesh 64 and the sheets 66 and 68 are inexpensive.

[0048] The mesh 64 includes a central rectangular heating element contact range portion 64a and a heating element non-contact range portion 64b that is continuous from the heating element contact range portion 64a and protrudes in the left and right directions. Specifically, the mesh 64 is an elongated shape, and its central portion corresponds to the heating element contact range portion 64a, and the other portions correspond to the heating element non-contact range portion 64b. A small step 64c corresponding to the thickness of the heat receiving plate 72 described later is formed at the boundary between the heating element contact range portion 64a and the heating element non-contact range portion 64b.

[0049] The heating element contact area 64a is a portion that contacts and receives heat from the surface of the bare chip 46. The mesh 64 is impregnated with liquid metal (thermal conductive fluid) 70 at least on almost the entire surface of the heating element contact area 64a. The heating element non-contact area 64b is substantially free of liquid metal 70, and the amount of liquid metal 70 used is suppressed to achieve cost reduction, and the adhesive material 74 described later becomes easy to impregnate.

[0050] The liquid metal 70 is, for example, a metal having gallium as its main component and being basically liquid at room temperature, but may also be a phase change material that is liquid at least at a temperature in a normal use state when the motherboard 24 is powered and the CPU 30 is running. The liquid metal 70 is a metal and therefore has excellent thermal conductivity and electrical conductivity. In addition, the liquid metal 70 is a liquid and therefore has fluidity.

[0051] The liquid metal 70 is impregnated over almost the entire surface of the heating element contact range 64a, and the liquid metal 70 contacts the surface of the bare chip 46 and the heat spreader 36, so that the two are well thermally connected. The liquid metal 70 is impregnated over almost the entire surface of the heating element contact range 64a, but depending on the conditions, there may be a portion that is not impregnated with the liquid metal 70, such as the end of the heating element contact range 64a, as a space for absorbing excess. The liquid metal 70 is impregnated in the mesh 64 and retained, so that even if there is a certain degree of vibration or impact, it will not leak to the surroundings.

[0052] The impregnation means may be, for example, to immerse the mesh 64 in a groove of the liquid metal 70 or to apply the liquid metal 70 to the mesh 64. There are cases where the liquid metal 70 is difficult to impregnate the mesh 64, but if the mesh 64 is a single body at the previous stage of being incorporated into the heat dissipation structure 60, it is easy to handle, and the six surfaces of the top, bottom, front, back, left and right are open, making it easy to impregnate the liquid metal 70. In addition, at this point, the mesh 64 is a single body, so it can be checked by visual observation or a predetermined means whether it is properly impregnated with the liquid metal 70.

[0053] The heating element contact area 64a is a rectangle that is the same as or slightly larger than the surface of the die 46 and covers the surface of the die 46. Some small holes may be provided in the heating element contact area 64a according to the heat distribution in the die 46 and used as liquid storage areas for the liquid metal 70.

[0054] The heat-generating body contact area 64a impregnated with the liquid metal 70 is thermally connected to the heat-generating plate 36 via the heat-receiving plate 72. The heat-receiving plate 72 is a metal plate such as copper, and can be regarded as a part of the heat-generating plate 36 as a heat sink. The heat-receiving plate 72 may be omitted.

[0055] The heat generating element non-contact range portion 64 b is formed continuously from the heat generating element contact range portion 64 a in the left-right direction, and the heat generating element non-contact range portion 64 b does not contact the surface of the bare chip 46 .

[0056] The mesh 64 will be further described. Figure 8 It is a cross-sectional view of the mesh 64 and its surroundings. Fig. 9 is an enlarged top view of the mesh 64. Figure 8 , Fig. 9 The liquid metal 70 is omitted. Fig.10 is a cross-sectional view of a mesh blank 92 . Fig.11 It is a schematic diagram showing a state in which the mesh 64 is produced by rolling the mesh blank 92 .

[0057] The mesh 64 is formed by weaving metal wires 90 in a longitudinal and transverse manner. Fig.11 As shown, the Fig.10 The mesh blank 92 shown is flattened in the thickness direction and cut into a specified length to make it. The thickness H0 of the mesh blank 92 is substantially twice the diameter of the wire 94 whose cross section is a perfect circle. In contrast, the thickness H of the flattened mesh 64 is about 0.4 to 0.6 times the thickness H0, specifically H0 is about 0.1 mm, and H is about 0.04 to 0.06 mm. At such a thickness H, the wire 90 becomes a moderately flat ellipse, and the plane portion 90a described below is reliably formed. In addition, since a certain degree of thickness is maintained, it is easy to impregnate the liquid metal 70, and less liquid metal 70 is required than the mesh blank 92.

[0058] The wire 90 of the mesh 64 is formed by flattening the wire 94 of the mesh blank 92, and is particularly flattened at the vertical and horizontal intersections 96, and its cross-section becomes a roughly elliptical shape that is thin in the thickness direction. In addition, the mesh 64 forms a planar portion 90a on the wire 90 at the intersection 96. The portion where the planar portion 90a is formed is the surface side and the back side of the mesh 64, in other words, the side where the wire 90 abuts against the bare chip 46 or the heat receiving plate 72, and is the side opposite to the side where the wire 90 faces each other. The planar portion 90a is formed by direct contact with the rollers 95, and becomes roughly elliptical when viewed from above (refer to Fig. 9 However, the plane portion 90a is not limited to a strict plane due to reasons such as manufacturing accuracy, and may be slightly curved as long as it forms an actual plane to a degree that can be distinguished from other surfaces as a trace of contact of the roller 95.

[0059] As described above, the cross section of the wire 90 that contacts the bare chip 46 and the heat receiving plate 72 is a flat, roughly elliptical shape along the surfaces of the contact objects, without local protrusions, and a flat portion 90a is formed at the intersection 96 of the contact, thereby ensuring a moderate contact area, so that the pressure is dispersed and the surface of the bare chip 46 and the heat receiving plate 72 can be maintained in a suitable state. In particular, the cover body that forms the surface of the bare chip 46 is made of ceramic or alloy, and there is a possibility that it is easily damaged by protrusions, but according to the mesh 64 as described above, the surface can be maintained in a suitable state. In addition, the mesh 64 can be passed through Fig.11 The rolling shown in the figure flattens the entire surface of the mesh blank 92 to form it simply, but depending on the manufacturing conditions, it is sufficient as long as the intersection points 96 of the vertical and horizontal wires 90 in the heating element contact area 64a are flattened in the thickness direction.

[0060] The mesh 64 is made of a metal material, and appropriate thermal conductivity can be obtained. When the mesh 64 is made of a metal material such as copper or aluminum, a material plated with a nickel material (including an alloy with nickel as a main component) can be used or a prescribed anti-corrosion treatment can be performed. That is, the mesh 64 can be prevented from being deteriorated by the liquid metal 70 by making at least the surface of the mesh 64 a nickel material or performing an anti-corrosion treatment. By forming the mesh 64 with a nickel material, the plating treatment can be omitted. In addition, by plating the copper material and the aluminum material with nickel, appropriate thermal conductivity can be obtained.

[0061] Back to Figures 4 to 7, the sheets 66 and 68 are, for example, thin resins in the form of films. The thickness of the sheets 66 and 68 is, for example, about 0.05 mm respectively. A pair of heating element non-contact range portions 64b are respectively clamped by a pair of sheets 66 and 68. The sheet 66 is the same as the sheet 68, but here the side that is pasted to the heat spreader 36 is the sheet 68, and the opposite side is the sheet 66. The sheets 66 and 68 overlap, and a part of them is used to clamp in three directions (up and down directions and right or left sides) surrounding the end of the heating element non-contact range portion 64b. The sheets 66 and 68 have a moderate area and can be reliably fixed to the heat spreader 36 by the adhesive tape 76 described later. The heating element non-contacting range 64b is basically free of liquid metal 70. However, even if it seeps out from the heating element contacting range 64a and diffuses into the heating element non-contacting range 64b, it will not leak further because it is covered by the sheets 66 and 68 in three directions.

[0062] The sheets 66, 68 and the mesh 64, and the sheets 66, 68 are fixed to each other by an adhesive material 74. The layer of the adhesive material 74 between the sheets 66, 68 is very thin. The adhesive material 74 is appropriately impregnated in the heating element non-contact range portion 64b of the mesh 64, and a high adhesive force can be obtained. The heating element non-contact range portion 64b can be almost entirely covered by the sheets 66, 68 according to design conditions, or a portion close to the heating element contact range portion 64a can be slightly exposed.

[0063] The sheet 68 and the heat spreader 36 are fixed by an adhesive tape (adhesive material) 76. The adhesive tape 76 fixes the heat conductive structure 62 to the heat spreader 36 with a moderate adhesive force, but can be removed as needed during maintenance. The thickness of the adhesive tape 76 is, for example, about 0.05 mm. Part of the overlapping sheets 66 and 68 can be attached to the frame 45 (see FIG. 4 ) according to design conditions. Figure 4 ) above, and can also be inserted under frame 45.

[0064] The sponge 65 is in a frame shape and blocks the space between the heat spreader 36 and the substrate 44 around the bare chip 46. A portion of the sponge 65 abuts against the heat spreader 36 via the portion of the sheets 66 and 68 that does not overlap with the mesh 64. That is, the sponge 65 is arranged to surround the mesh 64 when viewed from above. The liquid metal 70 basically does not contact the electrical components mounted on the motherboard 24, but by isolating the substrate 44 around the sponge 65, it is possible to further prevent the liquid metal 70 from leaking to the surroundings. In addition, the sponge 65 is arranged between the flange 48 and the heat spreader 36 and fixed by an adhesive material. As a result, the thickness of the sponge 65 can be made thinner and more stable.

[0065] Next, a part of the method for manufacturing the electronic device 10 will be described. Fig.12 This is a flowchart showing a part of the method for manufacturing the electronic device 10 .

[0066] In the assembly process of the heat dissipation structure 60, the first manufacturer first rolls the mesh blank 92 (see Fig.11 ), and cut into a predetermined length to obtain the mesh 64 (step S1). However, depending on the manufacturing conditions, the process of flattening the mesh blank 92 is not limited to the rolling process, and other stamping means may also be used. The above-mentioned nickel plating or anti-corrosion treatment may be performed before or after the rolling process. The mesh 64 is bent to be divided into a heating element contact range portion 64a and a heating element non-contact range portion 64b (see Figure 7 ).

[0067] Next, the first manufacturer assembles the thermally conductive structure 62. Here, Figure 7 As shown, the heating element non-contact range portion 64b at both ends of the mesh 64 is clamped by sheets 66 and 68, and fixed by adhesive material 74 as described above (step S2). Adhesive tape 76 is affixed to the opposite side of the sheet 68 that is opposite to the sheet 66. In addition, release paper 78 is affixed to the opposite side of the adhesive tape 76 that is opposite to the sheet 68 to protect the adhesive surface. The thickness of the release paper 78 is, for example, about 0.1 mm. One piece of release paper 78 can be provided over the two sheets 68, or two pieces can be provided separately for the two sheets 68.

[0068] The first manufacturer further impregnates the liquid metal 70 into the heating element contact range portion 64a in the mesh 64 (step S3). The timing of impregnation with the liquid metal 70 is, for example, after the heating element non-contact range portion 64b is clamped by the sheets 66 and 68. The heat-conductive structure 62 assembled by the first manufacturer is supplied to the second manufacturer. Such a heat-conductive structure 62 can be handled as a component and has portability. If a piece of release paper 78 is provided over two sheets 68, the release paper 78 can protect one surface of the heating element contact range portion 64a impregnated with the liquid metal 70 when the heat-conductive structure 62 is transported as a single unit. A protective film may also be provided on the other surface of the heating element contact range portion 64a during transportation.

[0069] The second manufacturer is a manufacturer that assembles the cooling module 22, and peels off the release paper 78 from the supplied thermally conductive structure 62. Figure 4 As shown in FIG. 1 , the sheet 68 with the adhesive tape 76 is mounted on a predetermined position of the heat spreader 36, and the sponge 65 is attached (step S4). Fig.13 As shown, the heat dissipation structure 60 (see Figure 5) is covered with a protective film 80. The cooling module 22 including the heat dissipation structure 60 assembled by the second manufacturer is supplied to the third manufacturer. In this way, the heat dissipation structure 60 is incorporated into the cooling module 22, so it can be handled integrally with the cooling module 22.

[0070] The third manufacturer is a manufacturer that assembles the electronic device 10, and peels off the protective film 80 from the supplied cooling module 22, such as Figure 2 As shown, the heat-generating element contacting region 64a of the mesh 64 in the heat-conducting structure 62 is sandwiched between the surface of the bare chip 46 and the heat spreader 36, and contacts both of them (step S5). The heat-generating element contacting region 64a is impregnated with the liquid metal 70, so that the thermal resistance between the bare chip 46 and the heat spreader 36 is very small.

[0071] In addition, the third-party manufacturer can treat the cooling module 22 including the heat dissipation structure 60 as a single component, and can install it in the housing 14 by simple operations such as screw fastening. In addition, the third-party manufacturer basically does not need to handle the liquid metal 70, and thus does not need a storage device or a coating device for the liquid metal 70, which is suitable for mass production assembly.

[0072] Furthermore, when the heat-conducting structure 62 needs to be replaced during repair or maintenance of the electronic device 10, the operator can simply attach the replacement heat-conducting structure 62, and there is no need to transport the electronic device 10 to a storage device or coating device having the liquid metal 70. Therefore, the repair work site, service base, etc. are not limited.

[0073] The heat-conducting structure 62 including the liquid metal 70 is removed together with the cooling module 22 or the heat spreader 36 during repair, so the heat-conducting structure 62 does not remain on the CPU 30 as a single body, and the liquid metal 70 does not scatter, making it easy to handle.

[0074] In the heat dissipation structure 60, the heat conductive structure 62, and the electronic device 10 as described above, the liquid metal 70 is impregnated in the heat generating element contacting area 64a of the mesh 64, so that leakage to the surroundings can be prevented, and the heat conductive performance between the bare chip 46 and the heat spreader 36 can be prevented from being reduced by the action of the liquid metal 70. In addition, the heat generating element contacting area 64a is clamped by the bare chip 46 and the heat receiving plate 72 and stabilized to a certain extent, but the heat generating element non-contacting area 64b at both ends is fixed to the heat spreader 36 via the sheets 66 and 68, respectively, so that the position of the mesh 64 can be further prevented from being shifted. The mesh 64 is slightly hard and is not suitable for being directly fixed to the heat spreader 36, but can be appropriately fixed to the heat spreader 36 by ensuring an appropriate area through the flexible sheets 66 and 68.

[0075] The pair of heating element non-contact range portions 64b are respectively sandwiched by a pair of sheets 66 and 68, so they have strength and are not easy to fall off, especially when the heat-conducting structure 62 is transported or installed as a single body. However, depending on the design conditions, the sheet 68 can be omitted, and the heat-conducting structure 62 can be fixed to the heat-spreading plate 36 only by the sheet 66. The sheets 66 and 68 sandwich the end of the heating element non-contact range portion 64b in three directions, but depending on the design conditions, they can also surround only the left and right directions, or only the front and rear directions.

[0076] As long as the heating element contact range portion 64a has a moderate area, the heat-conducting structure 62 can be applied to various bare chips 46, and there is no special restriction on the heat spreader 36 on the fixed side, so it has high versatility. The mesh 64 constituting the heat-conducting structure 62 is an elongated shape consisting of the heating element contact range portion 64a and the heating element non-contact range portions 64b on both sides thereof, so it can be particularly suitable for application to the horizontally long CPU 30 and bare chip 46. In the CPU 30 of the above example, the interval between the edge of the bare chip 46 and the flange 48 in the vertical direction is small, but the interval in the left and right direction is relatively large. By configuring the elongated mesh 64 along the left and right directions, the flange 48 is not easy to interfere with the sheets 66, 68, and the space is effectively utilized. The heat dissipation structure 60 and the heat-conducting structure 62 can also be applied to heat-generating electrical components other than the CPU 30 (such as the GPU 31).

[0077] The material impregnated in the mesh 64 is not limited to liquid metal 70, but may also be other thermally conductive fluids such as thermally conductive grease. The thermally conductive fluid mentioned in this application is not limited to liquids, but also refers to semi-solid, viscous and other fluid materials, including grease, oil compound and the like.

[0078] The present invention is not limited to the above-described embodiments, and can of course be freely modified within a scope not departing from the gist of the present invention.

Claims

1. A heat dissipation structure, which is a heat dissipation structure of a heat-generating electrical component, characterized in that: have: a metal mesh abutting against a surface of the electrical component; and a heat sink, sandwiching the metal mesh between the heat sink and the surface of the electrical component, The metal mesh is impregnated with a thermally conductive fluid at least in a portion in contact with the surface of the electric component, and has a shape that is compressed in the thickness direction at intersections of the vertical and horizontal wires.

2. The heat dissipation structure according to claim 1, characterized in that: The metal mesh has a flat surface formed on a side of the intersection where the wire material abuts against the electrical component or the heat sink.

3. The heat dissipation structure according to claim 1, characterized in that: The metal mesh has: A heating element contact range portion, the central portion of which is impregnated with a thermally conductive fluid and contacts the surface of the electrical component to receive heat; and A pair of heating element non-contacting range portions extend continuously from both sides of the heating element contacting range portion and do not contact the surface of the electrical component. The pair of the heat generating element non-contact range portions are fixed to the heat radiating element via sheets, respectively.

4. The heat dissipation structure according to claim 3, characterized in that: The pair of heating element non-contact range portions are respectively sandwiched by a pair of sheets.

5. The heat dissipation structure according to claim 1, characterized in that: A substrate and a semiconductor chip mounted on the substrate, The semiconductor chip comprises a substrate and a bare chip. The electrical component is the bare die.

6. An electronic device having a heat-generating electrical component, characterized in that: have: a metal mesh abutting against a surface of the electrical component; and a heat sink, sandwiching the metal mesh between the heat sink and the surface of the electrical component, The metal mesh is impregnated with a thermally conductive fluid at least in a portion in contact with the surface of the electric component, and has a shape that is compressed in the thickness direction at intersections of the vertical and horizontal wires.

7. A method for manufacturing an electronic device, the electronic device having a heat-generating electrical component, the method for manufacturing the electronic device comprising: A process for stamping a metal mesh; a step of impregnating the metal mesh with a thermally conductive fluid; and A step of sandwiching the metal mesh between the surface of the electric component and a heat sink.

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