Vapor chamber and method for manufacturing the same

Abstract

The present invention provides a vapor chamber that can be easily attached to a specified electronic component and exhibits desired heat exchange characteristics. [Solution] The vapor chamber 10 is provided with a resin body 12 having a depressurized space 14, and a wick structure 16 consisting of a plurality of carbon fiber filaments 16a extending along the inner surface of the bottom 12a of the body 12 facing the space 14. A heat source contact surface 19 is formed on the outer surface of the bottom 12a, where one end face of each end 16b of the carbon fiber filaments 16a is exposed by penetrating the bottom 12a. Furthermore, a refrigerant is sealed in the space 14, which is heated by the heat transferred from the heat source contact surface 19, generating vapor that moves to the inner surface of the body 12 away from the heat source contact surface 19, cools to become a condensate, and circulates by moving between the carbon fiber filaments 16a toward the heat source contact surface 19 through capillary action.

Description

Technical Field

[0001] The present invention relates to a vapor chamber used for cooling heat-generating components such as a CPU of an electronic device such as a personal computer, and a method for manufacturing the same.

Background Art

[0002] In recent years, electronic devices such as personal computers and smartphones have been required to be miniaturized and have higher performance, and semiconductor elements such as CPUs have also been miniaturized and have higher performance. With the increase in the high performance of semiconductor elements, the switching speed has increased, and the amount of heat generated has also increased rapidly. As a cooling device for efficiently removing such rapidly increasing heat generated by semiconductor elements, a vapor chamber is used.

[0003] As proposed in Patent Document 1 below, a vapor chamber includes a heat conduction member and a cooling member. The heat conduction member has a working medium, a wick structure, and a metal casing. The casing has an internal space for accommodating the working medium and the wick structure. The cooling member has an internal flow path through which a fluid can flow and is connected to an end of the heat conduction member. This wick structure is a porous metal sintered body such as a sintered body of metal powder such as copper, has a capillary structure, and the liquefied working medium can penetrate therein. It is also described in Patent Document 1 that carbon fiber can be used as the wick structure.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] According to the vapor chamber proposed in Patent Document 1 mentioned above, heat generated in semiconductor elements with high switching speeds can be efficiently removed. However, since the vapor chamber housing is made of metal, when used in miniaturized personal computers, smartphones, and other electronic devices, electrical insulation must be considered not only between the semiconductor element being installed but also between it and various surrounding elements. If an electrically insulating film, such as an electrically insulating paint, is formed on the entire surface of the metal housing, there is a problem in that the heat exchange characteristics of the vapor chamber itself are impaired.

[0006] The present invention was made to solve the aforementioned problems, and aims to provide a vapor chamber and a method for manufacturing the same that can be easily attached to a predetermined electronic component without considering electrical insulation from various elements installed in the surrounding area, and that can exhibit desired heat exchange characteristics. [Means for solving the problem]

[0007] To achieve the above objective, the vapor chamber is provided with a resin body having a reduced-pressure space formed inside, and a wick structure consisting of a plurality of carbon fiber filaments extending along the inner surface of the bottom of the body facing the space. The outer surface of the bottom of the body has a heat source contact surface to which an external heat source is contacted, where one end face of each end of the carbon fiber filaments penetrates the bottom and is exposed. The space is filled with a coolant, which is sealed inside the body. The coolant is heated by heat transferred from one end face of each end of the carbon fiber filaments exposed on the heat source contact surface, heating a portion of the carbon fiber filaments of the wick structure, generating vapor. This vapor then moves to the inner wall surface of the body away from the heat source contact surface, cools, and becomes a condensed liquid. This condensed liquid then moves between the carbon fiber filaments of the wick structure by capillary action towards the heat source contact surface and circulates.

[0008] Preferably, one end of the carbon fiber filament, including each end face of the carbon fiber filament exposed on the outer surface of the bottom of the frame, is bound with the same or a different resin as the resin forming the frame.

[0009] Preferably, the refrigerant is water, at least the surface of each of the carbon fiber filaments of the wick structure is hydrophilic, and the reduced pressure in the space is 30 mmHg or less.

[0010] Preferably, the aforementioned frame is formed of a carbon fiber reinforced resin that contains short fibrous carbon fibers.

[0011] Preferably, a bifurcated support column is provided on the inner surface of the bottom of the frame to support the lid, and the bifurcated portion of the bifurcated support column positions the wick structure toward the inner surface of the bottom.

[0012] A method for manufacturing a vapor chamber to achieve the above objective is as follows: one end of a plurality of carbon fiber filaments as a heat transfer material is made into a resin convergence portion; a resin plate is formed through which the resin convergence portion penetrates from one side to the other; the other side of the resin plate is polished so that one end face of each of the ends of the carbon fiber filaments is exposed on the other side of the resin plate; the other end of the carbon fiber filaments is bent along the one side of the resin plate to form a wick structure; then a space is provided inside with the one side of the resin plate on which the wick structure is formed as the inner bottom surface; and the carbon fiber filaments are provided on the other side of the resin plate. This method is characterized by forming a resin body with an exposed surface where one end face of each carbon fiber filament is exposed, which is then a heat source contact surface to which an external heat source is applied, and then injecting and sealing a refrigerant into the space, which is under a predetermined reduced pressure state, a portion of the carbon fiber filaments of the wick structure is heated by heat transferred from one end face of each of the carbon fiber filaments exposed to the heat source contact surface, generating vapor, which moves to the inner surface of the body away from the heat source contact surface, cools and becomes a condensate, which then moves between the carbon fiber filaments of the wick structure in the direction of the heat source contact surface by capillary action and circulates.

[0013] It is preferable to converge one end of the plurality of carbon fiber filaments with the same or a different resin as the resin forming the main body.

[0014] It is preferable to use water as the refrigerant, to hydrophilize at least the surface of each of the carbon fiber filaments of the wick structure, and to reduce the pressure in the space to 30 mmHg or less.

[0015] It is preferable to form the aforementioned body with a carbon fiber reinforced resin that contains short carbon fibers.

[0016] It is preferable to provide a bifurcated support column on the inner surface of the bottom of the frame to support the lid, and to position the wick structure toward the inner surface of the bottom using the bifurcated portion of the bifurcated support column. [Effects of the Invention]

[0017] In the vapor chamber according to the present invention, one end face of each carbon fiber filament, which forms the wick structure and has better thermal conductivity than copper, is exposed on the bottom outer surface of the resin body, forming a heat source contact surface. Therefore, heat from an external heat source is easily transferred to the wick structure within the space, and the desired heat exchange characteristics can be achieved. Furthermore, since the body of the vapor chamber according to the present invention is made of resin, which has excellent electrical insulation properties, it can be made lighter than conventional vapor chambers formed with metal housings, and can be easily installed around the electronic component to be installed without considering electrical insulation between the component and various elements installed around it. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram showing an example of a vapor chamber according to the present invention, where Figure 1(a) is a longitudinal cross-sectional view thereof, Figure 1(b) is a plan view from XX in Figure 1(a), and Figure 1(c) is a bottom view of the vapor chamber 10 shown in Figure 1(a). [Figure 2] Figure 1 is an explanatory diagram illustrating the cooling function of the vapor chamber 10. [Figure 3] It is a process diagram of a manufacturing method of the vapor chamber 10 shown in FIG. 1. [Figure 4] It is a schematic diagram showing another example of the vapor chamber according to the present invention, and is a longitudinal sectional view thereof. [Figure 5] It is a schematic diagram showing another example of the vapor chamber according to the present invention, and is a longitudinal sectional view thereof. [Figure 6] It is a schematic diagram showing another example of the vapor chamber according to the present invention, and is a longitudinal sectional view thereof. [Figure 7] It is a schematic diagram showing another example of the vapor chamber according to the present invention, and is a longitudinal sectional view thereof. [Figure 8] It is a schematic diagram showing another example of the vapor chamber according to the present invention, and is a longitudinal sectional view thereof. [Figure 9] It is a schematic diagram showing another example of the vapor chamber according to the present invention, and is a plan view thereof.

MODE FOR CARRYING OUT THE INVENTION

[0019] A schematic diagram of the vapor chamber according to the present invention is shown in FIG. 1. The housing 12 of the vapor chamber 10 shown in Fig. 1(a) is made of resin. The resin forming the housing 12 may be a polypropylene resin, a polyamide resin, a thermoplastic resin or a thermosetting resin as long as it can form the housing 12. Examples thereof include a polypropylene resin, a polyamide resin, a polyphenylene sulfide resin, a polyurethane resin, a vinyl ester resin, an epoxy resin, a phenol resin, an unsaturated polyester resin, a urea resin, a silicone resin, a thermosetting polyimide resin, etc. Among these, from the viewpoint of heat resistance, thermosetting resins such as epoxy resin, phenol resin, unsaturated polyester resin, urea resin, silicone resin, thermosetting polyimide resin, etc. and moisture-curing type resins such as silicone resin are preferable. By using carbon fiber reinforced polymer (CFRP) containing short carbon fibers as the resin forming the structure 12, the strength and thermal conductivity of the structure 12 can be improved, and the wall thickness of the structure 12 can be reduced, thus reducing the weight of the structure 12 and improving its thermal conductivity, which is preferable. The short carbon fibers may be either PAN-based carbon fibers or pitch-based carbon fibers. Although the short carbon fibers themselves have better conductivity than copper, CFRP has inferior conductivity to metal.

[0020] A space 14 is formed in such a structure 12. As shown in Figure 1(b), which is a plan view from XX in Figure 1(a), the space 14 is surrounded by a rectangular resin bottom 12a, resin side parts 12b erected along the periphery of the bottom 12a, and a rectangular resin lid 12c placed on the side parts 12b. The inner surfaces of the bottom 12a, side parts 12b, and lid 12c facing the space 14 are preferably treated to be hydrophilic in order to improve wettability with the refrigerant described later. In addition, the thickness of each of the bottom 12a, side parts 12b, and lid 12c varies depending on the resin used, but is preferably 0.01 to 2 mm.

[0021] A wick structure 16 is formed on the inner surface of the bottom portion 12a facing the space portion 14 by multiple carbon fiber filaments 16a extending along this inner surface. Either PAN-based carbon fiber filaments or pitch-based carbon fiber filaments can be used as the carbon fiber filaments 16a, but pitch-based carbon fiber filaments, which have high thermal conductivity, are preferable. The number of carbon fiber filaments 16a constituting the wick structure 16 is preferably 2,000 to 10,000, and a tow consisting of a large number of carbon fiber filaments 16a can be used. The gaps between the carbon fiber filaments 16a constituting this wick structure 16 are adjusted to be 0.01 mm or less. Therefore, when refrigerant condensate is dropped onto the wick structure 16, as described later, the condensate can move in a predetermined direction through the gaps between the carbon fiber filaments 16a by capillary action. The surface of these carbon fiber filaments 16a is also preferably treated to improve wettability with the refrigerant, as described later.

[0022] The wick structure 16 is positioned on the inner surface of the bottom 12a by a plurality of bifurcated resin support columns 18 that are installed at predetermined intervals on the inner surface of the bottom 12a and support the lid 12c. As shown in the partially enlarged view in Figure 1(a), each bifurcated support column 18 has a bifurcated portion 18a formed at its lower end, and a plurality of carbon fiber filaments 16a constituting the wick structure 16 are housed inside the bifurcated portion 18a and pressed against the inner surface of the bottom 12a for positioning. By housing the plurality of carbon fiber filaments 16a in the bifurcated portion 18a of the bifurcated support column 18 in this way, the gaps between the carbon fiber filaments 16a can be adjusted to a gap that allows the condensed liquid of the refrigerant to move in a predetermined direction by capillary action. It is preferable that the surface of the bifurcated support column 18 is also treated to be hydrophilic.

[0023] As shown in Figure 1(b), one end 16b of each of the multiple carbon fiber filaments 16a constituting the wick structure 16 is restrained by a resin 17 that is the same as or different from the resin forming the body 12, and as shown in Figure 1(a), it penetrates the bottom 12a, so that one end face of each of the carbon fiber filaments 16a (hereinafter simply referred to as one end 16b) is exposed on the outer surface of the bottom 12a. As shown in Figure 1(c), a heat source contact surface 19 is formed on the outer surface of the bottom 12a where each end face of the carbon fiber filaments 16a is exposed, to which an external heat source is contacted. In this way, by restraining the multiple end 16b of each of the carbon fiber filaments 16a with the resin 17, it is preferable that each end face of the carbon fiber filaments 16a is densely exposed on the heat source contact surface 19.

[0024] A refrigerant is sealed in the space 14 formed inside the structure 12, and the space 14 is depressurized so that the sealed refrigerant is released at a predetermined temperature. Examples of refrigerants include water, methanol, ethanol, ethylene glycol, propylene glycol, and naphthalene. Water, especially pure water, is preferably used as the refrigerant due to its safety and ease of use. When pure water is used as the refrigerant, it is preferable to depressurize the space 14 to 30 mmHg or less so that the pure water evaporates at 30°C or below. The amount of refrigerant sealed in the depressurized space 14 is preferably 20 to 50% of the volume of the space 14. The through hole 20 drilled in the side portion 12b shown in Figure 1(a) is used when depressurizing the space 14 and injecting the refrigerant into the space 14, as will be described later, and is sealed with a sealing material 22 such as adhesive.

[0025] As shown in Figure 1, when the heat source 24 is brought into contact with the heat source contact surface 19 formed on the outer surface of the bottom 12a of the body 12, and is tightly bonded to it via adhesive, the heat from the heat source 24 is transferred from each end face of the end 16b exposed to the heat source contact surface 19 to the carbon fiber filaments 16a of the wick structure 16 provided along the bottom surface of the space 14, heating the coolant between the carbon fiber filaments 16a. When the coolant between the carbon fiber filaments 16a reaches its boiling point under the reduced pressure of the space 14, it evaporates and becomes a vapor flow, moving along the inner surface of the lid 12c in a direction away from the heat source contact surface 19 (direction of arrow A in Figure 2). As the vapor flow moves, it gradually cools (dissipates heat) and condenses on the inner surface of the body 12 at a predetermined distance from the heat source contact surface 19 to form droplets, which then drip onto the wick structure 16. The condensate dripped onto the wick structure 16 moves as a condensate flow towards the heat source contact surface 19 (direction of arrow B in Figure 2) due to capillary action between the carbon fiber filaments 16a that make up the wick structure 16, and is reheated and evaporated again near the heat source contact surface 19. In this way, the vapor chamber 10 can remove heat from the heat source 24 by circulating the refrigerant sealed in its space 14 while repeatedly evaporating and condensing.

[0026] In the vapor chamber 10 shown in Figures 1 and 2, each end face of one end 16b that is exposed to the heat source contact surface 19 extends from the carbon fiber filament 16a of the wick structure 16. Since carbon fiber filaments have better thermal conductivity than copper, heat from the heat source 24 is easily transferred from each end face of the end 16b exposed to the heat source contact surface 19 to the carbon fiber filament 16 of the wick structure 16, thereby achieving the desired heat exchange characteristics. Furthermore, since the body 12 of the vapor chamber 10 is made of resin with excellent electrical insulation properties, it can be made lighter than conventional vapor chambers formed with metal housings. Moreover, even when the vapor chamber 10 is used in miniaturized personal computers, smartphones, and other electronic devices, it can be installed without considering electrical insulation between the electronic components to be installed and various elements installed around them.

[0027] The vapor chamber 10 shown in Figures 1 and 2 can be manufactured by the method shown in Figure 3. First, as shown in Figure 3(a), multiple aligned carbon fiber filaments 15 are inserted so that one end face of each filament abuts against the inner bottom surface of a container 30 containing a resin solution 32, and the resin solution 32 is permeated into one end of each carbon fiber filament 15 by capillary action. Furthermore, as shown in Figure 3(b), the resin solution 32 that has permeated into one end of each carbon fiber filament 15 hardens to form a resin 17 that restrains one end of each carbon fiber filament 15. After adjusting the multiple carbon fiber filaments 15 restrained by the resin 17 to a predetermined length, one end of each carbon fiber filament 15 is inserted into a container 34 containing a resin solution 36 that forms the bottom 12a of the body 12. At this time, each end face of the carbon fiber filament 15 abuts against the inner bottom surface of the container 34, as shown in Figure 3(c). By curing this resin solution 36, a resin plate 13 can be obtained through which one end of the carbon fiber filament 15, which is constrained by the resin 17, passes, as shown in Figure 3(d).

[0028] The obtained resin plate 13 is polished on one surface 13a to ensure that each end face of the carbon fiber filament 15 is reliably exposed on the surface 13a of the resin plate 13, as shown in Figure 3(e). Plasma treatment is applied to the carbon fiber filament 15 and the other surface 13b of the resin plate 13 as shown in Figure 3(e) to impart hydrophilicity to the surface of the carbon fiber filament 15 and the other surface 13b of the resin plate 13, which is preferable as it improves wettability with the refrigerant described later. This plasma treatment involves flowing a plasma in a helium-air mixture state along the carbon fiber filament 15, and hydrophilicity is achieved by active species such as OH radicals derived from oxygen, nitrogen, and water vapor in the air modifying the surface of the carbon fiber filament 15 with hydrophilic functional groups. Applying an anti-fogging agent to the plasma-treated carbon fiber filament 15 is preferable as it allows the hydrophilicity to be maintained for a long period of time. As anti-fogging agents, known anti-fogging agents such as fatty acid esters (e.g., glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, etc.), fatty acid amides (e.g., oleic acid amides, stearic acid amides, etc.), and fatty acid or aliphatic derivative-based surfactants (lipophilic surfactants) such as ethylene oxide adducts thereof can be used.

[0029] Subsequently, as shown in Figure 3(g), a resin lid portion 12c can be placed on a resin side portion 12b erected along the periphery of the other surface 13b of the resin plate 13 on which the wick structure 16 is formed, thereby obtaining a body 12 with the resin plate 13, which has a space 14 formed inside, as its bottom portion 12a. Multiple resin bifurcated support columns 18 that support the lid portion 12c are provided on the inner surface of the bottom portion 12a facing the space 14, and the bifurcated portion 18a of the bifurcated support columns 18 positions the wick structure 16 on the inner surface side of the bottom portion 12a. It is preferable to apply a hydrophilic treatment such as plasma treatment to the surfaces of the side portion 12b and the lid portion 12c facing the space 14, as well as the surfaces of the bifurcated support columns 18, to impart hydrophilicity.

[0030] A through-hole 20 is formed in a part of the side portion 12b of the frame 12 shown in Figure 3(g). A cleaning agent is injected into the space 14 through this through-hole 20 to clean the space 14, and then the cleaning agent is discharged. After that, a resin pipe 21 with a valve 23 is connected to the through-hole 20, and a vacuum pump (not shown) is operated to reduce the pressure in the space 14. When the pressure in the space 14 is reduced to a predetermined level, the valve 23 is closed and the vacuum pump is stopped. Next, the resin pipe 21 is connected to a refrigerant container (not shown), and a predetermined amount of refrigerant is injected into the space 14 by opening the valve 23. When the injection of refrigerant into the space 14 is complete, the valve 23 is closed, the resin pipe 21 between the through-hole 20 and the valve 23 is melted and the through-hole 20 is sealed, and the through-hole 20 is then completely sealed with a sealant.

[0031] Since the body 12 of the vapor chamber 10 shown in Figures 1 to 3 is made of resin, its thermal conductivity is lower compared to a metal body. Therefore, if the refrigerant vapor evaporated in the space 14 is not cooled easily and the heat exchange characteristics are reduced, as shown in Figure 4, a cooling section 25 can be formed in a part of the body 12 away from the heat source contact surface 19, for example, in the lid 12c, with multiple carbon fiber filaments 25a penetrating it, thereby making it easier for the refrigerant evaporation to condense and improving the heat exchange characteristics. Furthermore, as shown in Figure 5, a heat source contact surface 19 may be provided in the center of the outer surface of the bottom 12a of the frame 12. In this case, it is preferable to divide a plurality of carbon fiber filaments 16a extending from one end 16b, each end surface of which is exposed to the heat source contact surface 19, into two to form wick structures 16, 16.

[0032] Furthermore, when the heat source contact surface 19 of the vapor chamber 10 is attached to the heat source, the main body 12 may be attached at an angle, as shown in Figure 6. When the main body 12 is attached at an angle in this way, the liquid refrigerant sealed in the space 14 may accumulate in areas away from the heat source contact surface 19, such as the side 12b of the main body 12, where the carbon fiber filaments 16a of the wick structure 16 are not laid. In such cases, as shown in Figure 6, by extending a portion of the carbon fiber filaments 16a constituting the wick structure 16 to the inner wall surface of the side 12b of the main body 12, away from the heat source contact surface 19, the carbon fiber filaments 16a of the wick structure 16 can come into contact with the liquid refrigerant that accumulates on the side 12b of the main body 12, and can move toward the heat source contact surface 19 due to capillary action between the carbon fiber filaments 16a.

[0033] In the vapor chamber 10 described so far, the wick structure 16 is provided only on the inner surface of the bottom 12a of the main body 12. However, as shown in Figure 7(a), the wick structure 16 may also be provided on the inner surface of the bottom 12a and the inner surface of the lid 12c. The wick structures 16, 16 are positioned on the bottom and top surfaces of the space 14 by a plurality of bifurcated resin support columns 18 that are installed at predetermined intervals on the inner surface of the bottom 12a and support the lid 12c. As shown in the partially enlarged view of Figure 7(a), each of these bifurcated support columns 18 has a bifurcated portion 18a formed at its lower end and upper end. A plurality of carbon fiber filaments 16a constituting the wick structure 16 are housed inside the bifurcated portions 18a, 18a and are pressed against the inner surface of the bottom 12a and the inner surface of the lid 12c to position them.

[0034] The wick structure 16 provided on the inner surface side of the lid 12c, similar to the wick structure 16 provided on the inner surface side of the bottom 12a, has one end 16b of a plurality of carbon fiber filaments 16a constituting the wick structure 16 restrained by a resin 17 that is the same as or different from the resin that forms the body 12, so that it penetrates the lid 12c and one end face of each end 16b of the carbon fiber filaments 16a is exposed on the outer surface of the lid 12c, forming a heat source contact surface 19. In the vapor chamber 10 shown in Figure 7(a), both the heat source contact surface 19 on the bottom 12a side and the heat source contact surface 19 on the lid 12c side can contact a heat source. However, in the vapor chamber 10 shown in Figure 7(a), the heat source contact surface 19 on the bottom 12a side and the heat source contact surface 19 on the lid 12c side are located opposite each other. Therefore, for the liquid refrigerant to move between the carbon fiber filaments 16a of the wick structure 16 to the heat source contact surface 19 by capillary action, when the heat source is brought into contact with the heat source contact surface 19 on the lid 12c side, the lid 12c must be on the bottom side of the body 12.

[0035] In contrast to the vapor chamber 10 shown in Figure 7(a), the vapor chamber 10 shown in Figure 7(b) has heat source contact surfaces 19 on the bottom 12a side and heat source contact surfaces 19 on the lid 12c side located at different positions. When a heat source contacts the heat source contact surface 19 on the bottom 12a side, the heat source contact surface 19 on the lid 12c side can act as a cooling surface, thereby improving the heat exchange characteristics of the vapor chamber 10. Note that the vapor chamber 10 shown in Figure 7(b) is given the same component numbers as the vapor chamber 10 shown in Figure 7(a), and a detailed explanation is omitted.

[0036] If the carbon fiber filaments 16a constituting the wick structure 16 of the vapor chamber 10 are short and a single wick structure 16 cannot sufficiently cover the inner surface of the bottom 12a of the body 12, it is preferable to provide multiple wick structures 16-1 and wick structures 16-2 on the inner surface of the bottom 12a, as shown in Figure 8. One end face of each end 16b of the carbon fiber filament 16a constituting the wick structure 16-1 is exposed to the outer surface of the bottom 12a, forming a heat source contact surface 19. In addition, one end of the carbon fiber filament 16a constituting the wick structure 16-2 forms a relay portion 26 at a position on the bottom 12a different from the heat source contact surface 19. The end face of one end of the carbon fiber filament 16a forming the relay portion 26 is located inside the bottom 12a and is not exposed to the outer surface of the bottom 12a. The other end of the carbon fiber filament 16a of the wick structure 16-1 and the carbon fiber filament 16a near the intermediate portion 26 of the wick structure 16-2 mix together to sufficiently cover the inner surface of the bottom portion 12a of the main body 12. Furthermore, as shown in Figure 9, multiple wick structures 16-1 and wick structures 16-2 may be provided in parallel on the inner surface of the bottom portion 12a. [Industrial applicability]

[0037] The vapor chamber according to the present invention can be used to cool heat-generating components such as CPUs in electronic devices such as personal computers. [Explanation of Symbols]

[0038] 10: Vapor chamber, 12: Main body, 12a: Bottom, 12b: Side, 12c: Lid, 13: Resin plate, 13a: One side, 13b: Other side, 14: Space, 15, 16a, 25a: Carbon fiber filament, 16, 16-1, 16-2: Wick structure, 16b: One end of carbon fiber filament 16a, 17: Resin, 18: Bifurcated support, 18a: Bifurcated part, 19: Heat source contact surface, 20: Through hole, 21: Resin piping, 22: Sealing material, 23: Valve, 24: Heat source, 25: Cooling section, 26: Intermediate section, 30, 34: Container, 32: Resin solution, 36: Resin solution, A, B: Arrows

Claims

1. A resin body is provided with a reduced-pressure space formed inside, and a wick structure consisting of multiple carbon fiber filaments extending along the inner surface of the bottom of the body facing the space is provided. On the outer surface of the bottom of the frame, a heat source contact surface is formed, to which an external heat source is contacted, such that one end face of each end of the carbon fiber filament penetrates the bottom and is exposed. A vapor chamber is characterized in that a refrigerant is sealed within the space, which heats up a portion of the carbon fiber filaments of the wick structure by heat transferred from one end face of each end of the carbon fiber filaments exposed to the heat source contact surface, generating vapor that moves to the inner wall surface of the body away from the heat source contact surface, cools to become a condensate, and circulates by moving between the carbon fiber filaments of the wick structure toward the heat source contact surface through capillary action.

2. The vapor chamber according to claim 1, characterized in that one end of the carbon fiber filament, including each end face of the carbon fiber filament exposed on the outer surface of the bottom of the frame, is bonded with the same or a different resin as the resin forming the frame.

3. The vapor chamber according to claim 1, characterized in that the refrigerant is water, at least the surface of each of the carbon fiber filaments of the wick structure is hydrophilized, and the reduced pressure in the space is 30 mmHg or less.

4. The vapor chamber according to claim 1, characterized in that the body is formed of a carbon fiber reinforced resin containing short fibrous carbon fibers.

5. The vapor chamber according to claim 1, characterized in that a bifurcated support column for supporting the lid is provided on the inner surface of the bottom of the frame, and the bifurcated portion of the bifurcated support column positions the wick structure toward the inner surface of the bottom.

6. After forming a resin convergence portion at one end of multiple carbon fiber filaments as a heat transfer material, a resin plate is formed in which the resin convergence portion penetrates from one side to the other side. After polishing the other side of the resin plate so that one end face of each end of the carbon fiber filament is exposed on the other side of the resin plate, The other end of the carbon fiber filament is bent along one side of the resin plate to form a wick structure. Next, a space is formed inside the resin plate on which the wick structure is formed, with one side of the resin plate serving as the inner bottom surface, and a resin body is formed on the other side of the resin plate, with the exposed surface where one end face of each of the carbon fiber filaments is exposed serving as the heat source contact surface to which an external heat source is applied. A method for manufacturing a vapor chamber, characterized by injecting and sealing a refrigerant, wherein, within the space under a predetermined reduced pressure state, vapor generated when a portion of the carbon fiber filaments of the wick structure is heated by heat transferred from one end face of each end of the carbon fiber filaments exposed to the heat source contact surface, moves to the inner surface of the body away from the heat source contact surface, is cooled and becomes a condensate, which then circulates by moving between the carbon fiber filaments of the wick structure toward the heat source contact surface via capillary action.

7. The method for manufacturing a vapor chamber according to claim 6, characterized in that one end of the plurality of carbon fiber filaments is brought together with the same or a different resin as the resin forming the body.

8. The method for manufacturing a vapor chamber according to claim 6, characterized in that water is used as the refrigerant, at least the surfaces of the carbon fiber filaments of the wick structure are hydrophilized, and the pressure in the space is reduced to 30 mmHg or less.

9. The method for manufacturing a vapor chamber according to claim 6, characterized in that the body is formed of a carbon fiber reinforced resin containing short fibrous carbon fibers.

10. A method for manufacturing a vapor chamber according to claim 6, characterized in that a bifurcated support column for supporting the lid is provided on the inner surface of the bottom of the frame, and the bifurcated portion of the bifurcated support column positions the wick structure toward the inner surface of the bottom.

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