Heat pipe, electronic device, instrument, and method for manufacturing heat pipe

Abstract

As a result, heat circulation can be effectively performed regardless of the use posture of the heat pipe (20). A heat pipe (20) is a heat pipe including a tubular body (21) in which a working fluid is sealed, and a sintered body layer (22) formed by sintering a metal powder on an inner wall surface (21a) of the tubular body (21). The heat pipe (20) includes an evaporation section (201) in which the working fluid evaporates, a condensation section (202) in which the working fluid condenses, and an intermediate section (203) located between the evaporation section (201) and the condensation section (202). At least the intermediate section (203) includes, in a cross-section taken in a direction intersecting an extension direction of the heat pipe (20), a first thick portion having a first thickness (t1) and a second thick portion having a second thickness (t2), the second thickness (t2) being greater than the first thickness (t1). The first and second thick portions of the intermediate section (203) face each other at least partially across the center of the tubular body (21). The second thick portion comprises a combination of a tubular body (21) and a sintered body layer (22).

Description

Technical Field

[0001] The present disclosure relates to heat pipes, electronic devices, instruments, and methods of manufacturing heat pipes. Background Art

[0002] As disclosed in PTL 1, a cooling fan, radiator, heat pipe, and the like configured to cool heat-generating components on a circuit board are provided within electronic devices such as game consoles, personal computers, and server computers. Furthermore, as disclosed in PTL 2, a wick composed of sintered metal powder is provided on the inner wall of the heat pipe. A working fluid sealed within the heat pipe circulates through the capillary action of the wick.

[0003] [Citation List]

[0004] [Patent Document]

[0005] [PTL 1]

[0006] PCT Patent Publication No. WO2021 / 193879

[0007] [PTL 2]

[0008] Japanese Patent Application Laid-Open No. 2002-318085 Summary of the Invention

[0009] Technical issues

[0010] Here, since the working fluid sealed in the heat pipe is affected by gravity, the circulation efficiency of the working fluid may vary depending on the usage posture of the electronic device. Therefore, a heat pipe that can maintain thermal circulation efficiency regardless of the usage posture is required.

[0011] An object of the present disclosure is to provide a heat pipe, an electronic device, an instrument, and a method for manufacturing the heat pipe that can effectively perform heat circulation regardless of a usage posture.

[0012] Solution to the problem

[0013] The heat pipe proposed in the present disclosure is a heat pipe comprising: a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body, the heat pipe comprising an evaporation section in which the working fluid evaporates, a condensation section in which the working fluid condenses, and an intermediate section between the evaporation section and the condensation section. At least the intermediate section comprises a first thick portion having a first thickness and a second thick portion having a second thickness in a cross section taken along a direction intersecting with the extension direction of the heat pipe, the second thickness being greater than the first thickness. The first thick portion and the second thick portion of the intermediate section face each other at least partially across the center of the tubular body in the cross section. The second thick portion comprises a combination of the tubular body and the sintered body layer.

[0014] The electronic device proposed in the present disclosure is an electronic device having a housing for accommodating a heating component, a heat dissipation component and a heat pipe, wherein the heat pipe includes a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body. The heat pipe includes an evaporation section, a condensation section and an intermediate section, wherein the working fluid evaporates due to the heat from the heating component in the evaporation section, and condenses due to the heat dissipation effect of the heat dissipation component in the condensation section, and the intermediate section is located between the evaporation section and the condensation section. At least the intermediate section includes a first thick portion having a first thickness and a second thick portion having a second thickness in a cross section taken along a direction intersecting with the extension direction of the heat pipe, wherein the second thickness is greater than the first thickness. The first thick portion and the second thick portion of the intermediate section face each other at least partially across the center of the tubular body in the cross section. The second thick portion includes a combination of the tubular body and the sintered body layer.

[0015] The apparatus disclosed herein is an apparatus for forming a sintered body layer in a heat pipe, the heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body. The apparatus comprises a first extension portion extending along the extension direction of the tubular body and a second extension portion extending from an end of the first extension portion along the extension direction of the tubular body. The length from the center of the second extension portion to the outer wall surface thereof in a cross section taken along a direction intersecting the extension direction of the second extension portion is shorter than the length from the center of the first extension portion to the outer wall surface thereof in a cross section taken along a direction intersecting the extension direction of the first extension portion. The first extension portion includes a portion having a shorter length from the center of the first extension portion to the outer wall surface thereof in a cross section taken along a direction intersecting the extension direction of the first extension portion.

[0016] The method for manufacturing a heat pipe proposed in the present disclosure is a method for manufacturing a heat pipe, which includes a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body, the method comprising the following steps: inserting an instrument extending along the extension direction of the tubular body into the tubular body, filling the gap between the inner wall surface of the tubular body and the outer wall surface of the instrument with metal powder, and forming a sintered body layer in the gap by sintering the metal powder. The gap includes a first filling area and a second filling area. The second filling area has a larger width than the first filling area in the thickness direction of the tubular body. The first filling area includes such an area, a portion of which has a large width in the thickness direction of the tubular body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1Ais a perspective view illustrating an example of an electronic device in a vertical posture.

[0018] Figure 1B is a perspective view illustrating an example of an electronic device in a horizontal posture.

[0019] Figure 2 It is a plan view showing components provided in the housing of the device body.

[0020] Figure 3A is a cross-sectional view schematically showing a heat pipe and peripheral components in a state where the electronic device is in a vertical posture.

[0021] Figure 3B is a cross-sectional view schematically showing a heat pipe and peripheral components in a state where the electronic device is in a horizontal posture.

[0022] Figure 4 It is shown along Figure 3B and Figure 6 sectional view of the cross section of the heat pipe taken along the cutting line IV-IV shown in FIG.

[0023] Figure 5 is shown along Figure 3B sectional view of the cross section of the heat pipe taken along the cutting line VV shown in FIG.

[0024] Figure 6 is a cross-sectional view schematically showing a modified example of a heat pipe.

[0025] Figure 7 is a cross-sectional view schematically showing another modified example of the heat pipe.

[0026] Figure 8A is a perspective view showing an apparatus for forming a sintered body layer.

[0027] Figure 8B is a view schematically illustrating the manner in which filling with metal powder is performed.

[0028] Figure 8C is a cross-sectional view showing the manner in which a tubular body is filled with metal powder. DETAILED DESCRIPTION

[0029] Hereinafter, an electronic device proposed in the present disclosure will be described with reference to the accompanying drawings. Figure 1A is a perspective view illustrating an example of an electronic device in a vertical posture. Figure 1B is a perspective view illustrating an example of an electronic device in a horizontal posture. Figure 21 is a plan view showing components disposed within the housing of the device body. In the following description, the arrow G shown in each figure indicates the direction in which gravity acts (hereinafter referred to as the gravity direction G). Furthermore, in each figure, the side facing the gravity direction G is considered the lower side, and the side opposite thereto is considered the upper side.

[0030] [Electronic devices]

[0031] The electronic device according to the present embodiment is preferably a game machine, a personal computer, a server computer, or the like. Figure 1A and Figure 1B A game console is shown as an example of an electronic device. Figure 1A and Figure 1B As shown, the electronic device 10 may include a device body 11 and a first cover 12 and a second cover 13 covering the device body 11. The first cover 12 and the second cover 13 may have such sizes that they cover the entire device body 11, as shown in FIG. Figure 1A and Figure 1B as shown, or may be of such a size that they cover only a portion of the device body 11.

[0032] [Vertical and horizontal postures of electronic devices]

[0033] The electronic device 10 can preferably be used in at least two or more usage postures. The usage posture refers to the posture in which the electronic device 10 is used by the user. The electronic device 10 can be used in the following ways: Figure 1A The vertical posture shown and Figure 1B Level attitude settings shown.

[0034] In this specification, the term "vertical posture" refers to the posture of the electronic device 10, which is arranged so that at least a portion of the tubular body 21 of the heat pipe 20, which will be described later, extends substantially along the direction of gravity G, with the evaporation section 201 located on the lower side and the condensation section 202 located on the upper side. The term "horizontal posture" refers to the posture of the electronic device 10, which is arranged so that at least a portion of the tubular body 21 of the heat pipe 20 extends in a direction intersecting the direction of gravity G (substantially horizontal). The electronic device 10 is arranged in a horizontal posture with the second cover 13 positioned on the lower side.

[0035] A structure may be employed in which, when placed in a horizontal posture, the electronic device 10 is directly placed on a surface (placement surface) such as a table or floor so as to be stably supported thereon, or includes a stand member (not shown) attached thereto so as to be stably supported on the placement surface thereby. Similarly, a structure may be employed in which, when placed in a vertical posture, the electronic device 10 is directly placed on the placement surface so as to be stably supported thereon, or includes a stand member (not shown) attached thereto so as to be stably supported on the placement surface thereby.

[0036] [Device body]

[0037] The device body 11 includes a housing 11a. Figure 2 As shown, the housing 11a houses the heat pipe 20, the cooling fan 50, the power supply unit 60, the heat sinks 71, 72 and 73 as heat dissipation components, etc. In addition, the housing 11a houses a circuit board (not shown). Electronic components (refer to FIG. 1 ) as heat-generating components are mounted on the circuit board. Figure 3A The heat generating component 80 described later is preferably a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or the like.

[0038] The power supply unit 60 uses current supplied from an external power source and supplies this current as driving power to various components included in the device body 11, such as the CPU. The power supply unit 60 includes a housing 61. A circuit board including a transformer, a rectifier circuit, etc. is housed in the housing 61.

[0039] The heat sinks 71, 72, and 73 are directly connected to heat-generating components such as the CPU, or are thermally connected to the heat-generating components via a heat receiving block or heat pipe 20. Each heat sink 71, 72, and 73 preferably has a shape including a plurality of heat dissipation fins, for example. The cooling fan 50 creates an air flow through the interior of the housing 61 of the power supply unit 60 or through the heat sinks 71, 72, and 73.

[0040] [Heat pipe]

[0041] Next, refer to Figures 3A to 5 The configuration and function of the heat pipe 20 are described. Figure 3A is a cross-sectional view schematically showing a heat pipe and peripheral components in a state where the electronic device is in a vertical posture. Figure 3B is a cross-sectional view schematically showing a heat pipe and peripheral components in a state where the electronic device is in a horizontal posture. Figure 4 is shown along Figure 3B The cross-sectional view of the cross section of the heat pipe taken along the cutting line IV-IV is shown. Figure 5 is shown along Figure 3B The cross-sectional view of the heat pipe is taken along the cutting line VV shown in FIG. Figure 3A and Figure 3B The arrows shown within the tubular body 21 in represent the circulation of the working fluid sealed in the tubular body 21.

[0042] The heat pipe 20 includes a tubular body 21 in which a working fluid is sealed and a sintered body layer 22 formed by sintering metal powder on an inner wall surface 21a of the tubular body 21. Note that sintering means solidifying a powdered metal mass by heating at a high temperature but below the melting point of the metal.

[0043] The material of the tubular body 21 is not limited to a specific material, but the tubular body 21 preferably contains a metal having high thermal conductivity. The working fluid may be a working fluid appropriately selected according to the material of the tubular body 21, etc., and is preferably water, for example.

[0044] The tubular body 21 is preferably arranged so that at least a portion thereof extends substantially along the direction of gravity when the electronic device 10 is in a vertical posture. Figure 3A and Figure 3B A configuration is shown in which the tubular body 21 extends straight in one direction, but the configuration is not limited thereto, and a portion of the tubular body 21 may be bent or twisted.

[0045] The sintered body layer 22 is preferably formed by sintering copper powder, for example. Note that in the following description, the sintered body layer is denoted by reference numerals "22a" or "22b," depending on the location at which the sintered body layer is formed. In the description, where there is no particular need to distinguish a sintered body layer from another sintered body layer, it will be simply referred to as "sintered body layer 22."

[0046] The heat pipe 20 includes an evaporation section 201, a condensation section 202, and an intermediate section 203. Note that the evaporation section 201, the condensation section 202, and the intermediate section 203 are parts of the heat pipe 20 and are preferably configured in a manner of being continuously connected to each other rather than being physically separated from each other.

[0047] At least a portion of the outer surface of the evaporation section 201 is arranged to be in contact with the heat-generating component 80, and the working fluid evaporates in the evaporation section 201 due to the heat from the heat-generating component 80. Note that the evaporation section 201 is not limited to such an arrangement in which the tubular body 21 is in direct contact with the heat-generating component 80, and it is sufficient if the evaporation section 201 is arranged so that at least the working fluid sealed in the tubular body 21 evaporates due to the heat from the heat-generating component 80.

[0048] At least a portion of the outer surface of the condensing section 202 is arranged to be in contact with the radiator 73, and the working fluid is condensed in the condensing section 202 by the heat dissipation effect of the radiator 73. Note that the condensing section 202 is not limited to such an arrangement in which the tubular body 21 is in direct contact with the radiator 73, and it is sufficient if the condensing section 202 is provided so that at least the working fluid sealed in the tubular body 21 is condensed due to the heat dissipation effect of the radiator 73.

[0049] The middle section 203 is disposed between the evaporation section 201 and the condensation section 202. That is, one end of the heat pipe 20 is the evaporation section 201, the other end is the condensation section 202, and the portion between the evaporation section 201 and the condensation section 202 is the middle section 203.

[0050] The working fluid in evaporation section 201 is heated and vaporized by the heat from heat-generating component 80. The vaporized working fluid, now a gas, moves through intermediate section 203 to condensation section 202. In heat pipe 20, a hollow space (hereinafter referred to as hollow space C) is formed within tubular body 21 and sintered body layer 22. Hollow space C serves as a flow path for the vaporized working fluid.

[0051] The working fluid that has moved to the condensing section 202 condenses and liquefies due to the heat dissipation effect of the radiator 73. The liquefied working fluid, now a liquid, moves along the inner wall of the heat pipe 20 through the intermediate portion 203 to the evaporating section 201. Furthermore, the working fluid that has moved to the evaporating section 201 is heated and vaporized by the heat from the heat generating component 80. Thus, in the heat pipe 20, the working fluid refluxes within the tubular body 21, transferring heat from the evaporating section 201 to the condensing section 202, thereby preventing the temperature of the heat generating component 80 from rising.

[0052] Furthermore, in the heat pipe 20, a sintered body layer 22 is formed on the inner wall surface 21a of the tubular body 21 to allow the liquefied working fluid to move from the condensation section 202 to the evaporation section 201. The sintered body layer 22 has a large number of voids formed according to the shape and particle size of the sintered metal powder. The liquefied working fluid can move within the sintered body layer 22 due to the capillary force of the sintered body layer 22. In other words, the liquefied working fluid can move from the condensation section 202 to the evaporation section 201 through the voids in the sintered body layer 22.

[0053] Here, when the electronic device 10 is in a vertical position, the direction of movement of the working fluid from the condensation section 202 to the evaporation section 201 coincides with the direction of gravity G. Therefore, in addition to the capillary force described above, the working fluid can also move smoothly due to the influence of gravity. On the other hand, when the electronic device 10 is in a horizontal position, the direction of movement of the working fluid from the condensation section 202 to the evaporation section 201 differs from the direction of gravity G, making it more difficult for the working fluid to move compared to when the electronic device 10 is in a vertical position.

[0054] Furthermore, in the circulation of the working fluid, the movement of the vaporized working fluid from the evaporation section 201 to the condensation section 202 and the movement of the liquefied working fluid from the condensation section 202 to the evaporation section 201 proceed in parallel. In other words, in the circulation of the working fluid, the movement of the vaporized working fluid from the evaporation section 201 to the condensation section 202 and the movement of the liquefied working fluid from the condensation section 202 to the evaporation section 201 form countercurrents. Therefore, the vaporized working fluid generates a force that acts as resistance to the movement of the liquefied working fluid. Therefore, in some cases, the circulation of the working fluid is affected by the flow rate of the vaporized working fluid.

[0055] Therefore, the heat pipe 20 adopts a configuration in which Figure 5 As shown, the middle section 203 includes a first thick portion having a first thickness t1 and a second thick portion having a second thickness t2 in a cross section taken along a direction orthogonal to the extending direction of the tubular body 21 (a direction intersecting the extending direction of the tubular body 21). Note that the thickness of the tubular body 21 may be the same regardless of its portion.

[0056] In this embodiment, the second thick portion comprises the tubular body 21 and the sintered body layer 22a. That is, the thickness t2 is the total thickness of the tubular body 21 and the thickness of the sintered body layer 22a. On the other hand, the first thick portion comprises only the tubular body 21. That is, the thickness t1 is the thickness of the tubular body 21 itself. Therefore, the second thickness t2 of the second thick portion is greater than the first thickness t1 of the first thick portion. In this manner, the sintered body layer 22 is formed on a predetermined portion of the inner wall surface 21a in the middle section 203 of the heat pipe 20. In other words, in the heat pipe 20, the middle section 203 includes a portion of the inner wall surface 21a where the sintered body layer 22 is not formed.

[0057] Since the middle section 203 includes a portion in which the sintered body layer 22a is not formed, the inner diameter of the hollow space C in the middle section 203 is relatively wide. That is, the flow path in the middle section 203 is wider than the flow path in a configuration in which the sintered body layer 22 is formed over the entire circumference of the inner wall surface 21a. Therefore, the flow rate of the vaporized working fluid in the middle section 203 is slower than the flow rate in a configuration in which the sintered body layer 22 is formed over the entire circumference.

[0058] In addition, in the heat pipe 20, as Figure 3B and Figure 5 As shown, in a state where the electronic device 10 is in a horizontal posture, the sintered body layer 22 a is formed so as to be located only in the lower portion of the middle section 203 .

[0059] When the electronic device 10 is in a horizontal position, the working fluid liquefied in the condensation section 202 moves toward the lower portion of the heat pipe 20 due to the influence of gravity. Therefore, the working fluid moves to the evaporation section 201 due to the capillary force of the sintered body layer 22a formed at the lower portion of the intermediate section 203.

[0060] Note that although Figure 5While an example is shown in which the sintered body layer 22a is formed with a predetermined width along the circumferential direction at the lower portion of the middle section 203, the shape of the sintered body layer 22a is not limited thereto. The sintered body layer 22a is preferably formed so that, when the electronic device 10 is in a horizontal position, at least a portion thereof is located at the lowest portion of the inner wall surface 21a of the tubular body 21 in the middle section 203. In other words, the second thick portion having a thickness t2 preferably includes at least the lowest portion of the tubular body 21 in the middle section 203 when the electronic device 10 is in a horizontal position.

[0061] Furthermore, the sintered body layer 22a is preferably formed so as to be located below the center O1 of the tubular body 21 when the electronic device 10 is in a horizontal posture. That is, when the electronic device 10 is in a horizontal posture, the second thick portion having a thickness t2 is preferably formed so as to be located at the center O1 of the tubular body 21 in a cross section taken in a direction perpendicular to the extending direction of the tubular body 21 (see FIG. Figure 5 ) below. In addition, it is preferable that, in the tubular body 21 having a circular cross-sectional shape, the formation range of the sintered body layer 22a is preferably Figure 5 The central angle θ shown is 120° or more but less than 180°.

[0062] The condensation section 202 preferably includes a first thick portion having a first thickness t1 and a second thick portion having a second thickness t2 in a cross section taken along a direction perpendicular to the extension direction of the tubular body 21. Furthermore, the second thick portion of the intermediate section 203 is preferably connected to the second thick portion of the condensation section 202. That is, the sintered body layer 22a of the intermediate section 203 and the sintered body layer 22a of the condensation section 202 are preferably formed substantially flush with each other without a step in the extension direction. This allows the thickness of the condensation section 202 to be similar to that of the intermediate section 203, thereby widening the flow path of the working fluid.

[0063] like Figure 4 As illustrated, the sintered body layer 22b formed on the inner wall surface 21a of the evaporation section 201 is preferably formed over the entire circumference in a cross section taken in a direction perpendicular to the extending direction of the tubular body 21. Figure 3A and Figure 3BAs shown, the sintered body layer 22b formed on the inner wall surface 21a in the evaporation section 201 is preferably formed over the entire length of the evaporation section 201 in the direction of extension of the tubular body 21. Furthermore, the evaporation section 201 preferably includes a third thick portion having a third thickness t3. The third thick portion comprises a combination of the tubular body 21 and the sintered body layer 22b and has a thickness greater than the second thickness t2 of the second thick portion. In other words, the thickness of the sintered body layer 22b formed on the inner wall surface 21a of the tubular body 21 in the evaporation section 201 is preferably greater than the thickness of the sintered body layer 22a formed on the inner wall surface 21a of the tubular body 21 in the intermediate section 203.

[0064] However, the shape of the sintered body layer 22b formed on the inner wall surface 21a of the tubular body 21 in the evaporation section 201 is not limited to Figure 4 Also in the evaporation section 201 , in a state where the electronic device 10 is in a horizontal posture, the sintered body layer 22 b may be formed only in the lower portion of the evaporation section 201 .

[0065] In addition, if Figure 3A As shown in FIG. 1 , at least a portion of the intermediate section 203 on the evaporation section 201 side preferably includes a third thick portion having a third thickness t3. Furthermore, the third thick portion of the intermediate section 203 is preferably connected to the third thick portion of the evaporation section 201. In other words, the third thick portion is preferably provided not only in the evaporation section 201 but also partially in the intermediate section 203. In this manner, the sintered body layer 22 is formed thicker in areas potentially affected by resistance from the vaporized working fluid, thereby allowing the liquefied working fluid to easily return to the evaporation section 201. Consequently, the circulation of the working fluid becomes smoother.

[0066] In addition, if Figure 5 As shown, the first thick portion and the second thick portion of the middle section 203 preferably face each other at least partially across the center O1 of the tubular body 21. That is, the cross-sectional shape of the middle section 203 is preferably asymmetrical with the center O1 of the tubular body 21 as the symmetry center.

[0067] Furthermore, in this embodiment, the heat pipe 20 has been described as being provided in an electronic device 10 to be used in either a vertical or horizontal position. However, this embodiment is not limited thereto. For example, the heat pipe 20 may be provided in an electronic device to be used in one position. In this case, the electronic device's position of use is preferably the horizontal position described in this embodiment.

[0068] In addition, in the present embodiment, the tubular body 21 having a circular cross-sectional shape has been described by way of example, but the tubular body 21 is not limited thereto. That is, the cross-sectional shape of the tubular body 21 may be an ellipse or a rectangle.

[0069] Furthermore, although not shown, a plurality of grooves extending in the extending direction of the tubular body 21 are preferably formed in the inner wall surface 21 a of the tubular body 21 in each of the evaporation section 201, the condensation section 202, and the intermediate section 203. Furthermore, the sintered body layer 22 is preferably formed in the plurality of grooves formed in the inner wall surface 21 a of the tubular body 21. Since capillary force can also be generated in the plurality of grooves, movement of the liquefied working fluid can be performed more smoothly.

[0070] [in conclusion]

[0071] As described above, in the heat pipe 20 according to this embodiment, the flow path for the working fluid can be made relatively wide without increasing the diameter of the tubular body 21 itself. Therefore, the flow rate of the vaporized working fluid moving from the evaporation section 201 to the condensation section 202 can be made relatively slow. In addition, a configuration is adopted in which the sintered body layer 22 is formed at the lower part of the tubular body 21 when the electronic device 10 is in a horizontal posture. As a result, even when the electronic device 10 is in a horizontal posture, the working fluid is easily moved due to capillary force. Therefore, the liquefied working fluid can be smoothly moved from the condensation section 202 to the evaporation section 201. As a result, regardless of the usage posture of the electronic device 10, the heat cycle can be effectively performed.

[0072] Furthermore, in the heat pipe 20 according to this embodiment, the amount of metal powder used to form the sintered body layer 22 can be reduced compared to a configuration in which the sintered body layer 22 is formed over the entire circumference of the inner wall surface 21a of the tubular body 21. Therefore, the manufacturing cost can be reduced.

[0073] [Modification]

[0074] Figure 6 is a view schematically illustrating a modified example of a heat pipe. Figure 7 is a view schematically illustrating another modified example of the heat pipe.

[0075] In connection with this embodiment Figure 3A In the examples, the position and thickness of the sintered body layer 22 in the condensation section 202 are similar to those in the middle section 203. However, the sintered body layer 22 is not limited thereto, and may be, for example, Figure 6As shown in the example, a portion of the condensation section 202 is not formed. In addition, although not shown, a sintered body layer having a thickness smaller than that of the sintered body layer 22a formed in the intermediate section 203 can be formed in the condensation section 202. That is, the thickness of the combination of the tubular body 21 and the sintered body layer 22 can be gradually reduced from the evaporation section 201 side toward the condensation section 202 side. By configuring in this way, the flow path of the vaporized working fluid can be further widened. As a result, the flow of the vaporized working fluid can be slowed down, and the movement of the liquefied working fluid can be smoothly performed. Furthermore, since the amount of metal powder used to form the sintered body layer 22 can be reduced, the manufacturing cost can be reduced.

[0076] In addition, in connection with this embodiment Figure 3A In the examples of FIG. 2 and FIG. 3 , the sintered body layer 22a is not formed in a part of the middle section 203. However, the sintered body layer 22a is not limited thereto and may be formed as shown in FIG. Figure 7 As shown, the first thick portion having the first thickness t1 in the middle section 203 is preferably formed over the entire circumference of the tubular body 21 in the circumferential direction. That is, the first thick portion having the first thickness t1 in the middle section 203 preferably includes a combination of the tubular body 21 and the sintered body layer 22a. That is, the sintered body layer 22a may be formed over the entire circumference in the middle section 203 so as to partially have different thicknesses in the circumferential direction, that is, to include a portion having a smaller thickness than other portions. Figure 7 As shown, the first thick portion and the second thick portion of the middle section 203 preferably face each other at least partially across the center of the tubular body 21. That is, the cross-sectional shape of the middle section 203 is preferably asymmetrical with the center of the tubular body 21 as the symmetry center. Figure 7 As shown, when the electronic device 10 is in a horizontal position, the second thick portion having the second thickness t2 is preferably located on the lower side. This configuration allows for a relatively wide flow path for the vaporized working fluid, generating capillary forces within the sintered layer 22 along the entire circumference of the tubular body 21. This enables efficient thermal cycling.

[0077] [Method of manufacturing heat pipe]

[0078] Next, refer to Figures 8A to 8C , a method for manufacturing a heat pipe is described. Figure 8A It is a perspective view of an apparatus for forming a sintered body layer. Figure 8B is a view schematically illustrating the manner in which filling with metal powder is performed. Figure 8C is a view showing the manner in which the tubular body has been filled with metal powder, and is a view along Figure 8B The cross section is taken along line IIX-IIX shown in FIG. Note that Figure 8CA broken line shown in FIG. 8 is an imaginary line indicating a second extending portion 92 to be described later.

[0079] Here, a method for manufacturing a heat pipe is described in which a sintered body layer 22a is formed over the entire circumference in the peripheral direction of the tubular body 21 in the middle section 203, similar to the method described above. Figure 7 The heat pipe 20 is shown in FIG. Note that Figures 8A to 8C O2 shown in ⊂ indicates the center of the instrument 90 in a cross section taken along a direction orthogonal to the extending direction of the instrument 90 .

[0080] In the manufacturing process of heat pipes, Figure 8A The sintered body layer 22 is formed using the apparatus 90 illustrated in FIG. The apparatus 90 is used as a mold when forming the sintered body layer 22. The apparatus 90 preferably has a shape extending in the extending direction of the tubular body 21 and has a size capable of being inserted into the tubular body 21.

[0081] The instrument 90 includes a first extension portion 91 and a cylindrical second extension portion 92. The first extension portion 91 has a shape extending in the same direction as the tubular body 21. The second extension portion 92 has a shape extending from the end of the first extension portion 91 in the same direction as the first extension portion 91 and has a smaller diameter than the first extension portion 91. Figure 8C As shown, in a cross section taken along a direction intersecting the extension direction of the instrument 90, the length r2 from the center O2 of the instrument 90 to the outer wall surface 92a of the second extension portion 92 is smaller than the lengths r11 and r12 from the center O2 of the instrument 90 to the outer wall surface 91a.

[0082] Further, in a cross section taken along a direction orthogonal to the extending direction of the instrument 90, the first extending portion 91 includes a portion having a small length from the center O2 of the instrument 90 to the outer wall surface 91a in the cross section. Specifically, as Figure 8C As shown, a portion of first extension portion 91 has a length r11, which is the length from center O2 to outer wall surface 91a, and another portion thereof has a length r12, which is smaller than length r11. That is, outer wall surface 91a of first extension portion 91 has a first outer peripheral surface 911a having a radius r11 and a second outer peripheral surface 912a having a radius r12, and the radius of second outer peripheral surface 912a (second radius) is smaller than the radius of first outer peripheral surface 911a (first radius).

[0083] First, if Figure 8BAs shown, the instrument 90 is inserted into the tubular body 21. The instrument 90 is preferably inserted so that its center O2 is aligned with the center O1 of the tubular body 21. In this state, a gap is formed between the tubular body 21 and the instrument 90. Specifically, a first filling area F1, to be filled with metal powder, is formed between the inner wall surface 21a of the tubular body 21 and the outer wall surface 91a of the first extension 91. Furthermore, a second filling area F2, to be filled with metal powder, is formed between the inner wall surface 21a of the tubular body 21 and the outer wall surface 92a of the second extension 92. The second filling area F2 is wider than the first filling area F1 in the thickness direction of the tubular body 21. The first filling area F1 includes a region having a large width in the thickness direction of the tubular body 21.

[0084] like Figure 8B As shown, the first filling region F1 is a region for forming the sintered body layer 22 in the entire condensation section 202 and a portion of the middle section 203 of the heat pipe. The second filling region F2 is a region for forming the sintered body layer 22 in the entire evaporation section 201 and a portion of the middle section 203 of the heat pipe.

[0085] like Figure 8B As shown, the instrument 90 is preferably inserted into the tubular body 21 so that the first extension 91 is positioned on the lower side of the second extension 92 in the direction of gravity G. In addition, the tubular body 21 and the instrument 90 are preferably fixed so that their relative positions do not change in a state in which the instrument 90 is inserted into the tubular body 21. Note that, although not shown, the end portion of the lower side of the tubular body 21 in the direction of gravity may be subjected to terminal processing, for example, by swaging or the like.

[0086] Next, the first filling region F1 and the second filling region F2 are filled with metal powder. Figure 8B Each arrow illustrated in indicates a moving direction of the metal powder when filling with metal powder is performed. That is, Figure 8B The method of introducing metal powder from the second extension portion 92 side in the extending direction of the instrument 90 is illustrated. First, the first filling area F1 is filled with metal powder, and then the second filling area F2 is filled with the same. Then, vibration is preferably applied to the entire area, for example, to complete the filling.

[0087] Afterwards, the tubular body 21 and the instrument 90 are sintered together to form the sintered body layer 22. After sintering, the instrument 90 is preferably withdrawn from the interior of the tubular body 21. In this manner, the metal powder filling the first filling region F1 serves as the sintered body layer 22a in the first and second thick portions. The metal powder filling the second filling region F2 becomes the sintered body layer 22b in the third thick portion.

[0088] Note that the shape and size of the instrument 90 are not limited to Figure 8A For example, in the manufacture of Figure 3A In the case of the heat pipe 20 shown, the diameter of a portion of the first extension portion 91 of the instrument 90 for forming the first thick portion is preferably the same as the diameter of the inner wall surface 21a of the tubular body 21. That is, the length r11 from the center O2 to the outer wall surface 91a of the first extension portion 91 is preferably the same as the inner diameter of the tubular body 21. In addition, the instrument 90 is not limited to an instrument including one member and may include a plurality of members for forming the first filling region F1 and the second filling region F2.

[0089] [Supplementary Notes]

[0090] For example, the heat pipe, electronic device, instrument, and method of manufacturing the heat pipe may also have the following configurations.

[0091] (1) A heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body, the heat pipe comprising an evaporation section in which the working fluid evaporates, a condensation section in which the working fluid condenses, and an intermediate section located between the evaporation section and the condensation section, wherein at least the intermediate section comprises a first thick portion having a first thickness and a second thick portion having a second thickness in a cross section taken along a direction intersecting an extension direction of the heat pipe, the second thickness being greater than the first thickness, the first thick portion and the second thick portion of the intermediate section at least partially facing each other across the center of the tubular body in the cross section, and the second thick portion comprising a combination of the tubular body and the sintered body layer.

[0092] (2) The heat pipe according to (1), wherein the first thick portion includes a combination of the tubular body and the sintered body layer.

[0093] (3) The heat pipe according to (1), wherein the first thick portion includes only the tubular body.

[0094] (4) The heat pipe according to any one of (1) to (3), wherein at least the evaporation section includes a third thick portion having a third thickness, and the third thick portion includes a combination of the tubular body and the sintered body layer and has a thickness greater than that of the second thick portion.

[0095] (5) The heat pipe according to (4), wherein at least a portion of the middle section on one side of the evaporation section includes the third thick portion.

[0096] (6) The heat pipe according to (4) or (5), wherein the third thick portion of the intermediate section is connected to the third thick portion of the evaporation section.

[0097] (7) The heat pipe according to any one of (1) to (6), wherein the condensation section includes the first thick portion and the second thick portion in a cross section taken along a direction intersecting an extending direction of the tubular body.

[0098] (8) The heat pipe according to (7), wherein the second thick portion of the middle section is connected to the second thick portion of the condensing section.

[0099] (9) The heat pipe according to any one of (1) to (8), wherein the sintered body layer on the inner wall surface of the evaporation section is formed over the entire circumference in a cross section taken along a direction intersecting the extending direction of the tubular body.

[0100] (10) The heat pipe according to any one of (1) to (9), wherein the sintered body layer on the inner wall surface of the evaporation section is formed over the entire length of the evaporation section in the extending direction of the tubular body.

[0101] (11) The heat pipe according to any one of (1) to (10), wherein a thickness of a combination of the tubular body and the sintered body layer gradually decreases from a side of the evaporation section toward a side of the condensation section.

[0102] (12) An electronic device having a housing for accommodating a heating component, a heat dissipating component and a heat pipe, the heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body, the heat pipe comprising an evaporation section, a condensation section and an intermediate section, in the evaporation section, the working fluid evaporates due to heat from the heating component, in the condensation section, the working fluid condenses due to the heat dissipation effect of the heat dissipating component, the intermediate section being located between the evaporation section and the condensation section, wherein at least the intermediate section comprises a first thick portion having a first thickness and a second thick portion having a second thickness in a cross section taken along a direction intersecting with an extension direction of the heat pipe, the second thickness being greater than the first thickness, the first thick portion and the second thick portion of the intermediate section at least partially facing each other across the center of the tubular body in the cross section, and the second thick portion comprising a combination of the tubular body and the sintered body layer.

[0103] (13) The electronic device according to (12), wherein at least a portion of the evaporation section is provided in contact with the heat-generating component, and at least a portion of the condensation section is provided in contact with the heat-radiating component.

[0104] (14) The electronic device according to (12) or (13), wherein, when the electronic device is in a predetermined use posture, at least a portion of the second thick portion is arranged to be located at a lowermost portion of the heat pipe.

[0105] (15) The electronic device according to any one of (12) to (14), wherein the second thick portion is provided below the center in the vertical direction of the tubular body when the electronic device is in a predetermined use posture.

[0106] (16) An apparatus for forming a sintered body layer in a heat pipe, the heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body, the apparatus comprising a first extension portion extending in an extension direction of the tubular body and a second extension portion extending from an end of the first extension portion in the extension direction of the tubular body, wherein a length from a center of the second extension portion to an outer wall surface thereof in a cross section taken along a direction intersecting the extension direction of the second extension portion is smaller than a length from a center of the first extension portion to an outer wall surface thereof in a cross section taken along a direction intersecting the extension direction of the first extension portion, and the first extension portion includes a portion having a small length from a center of the first extension portion to an outer wall surface in a cross section taken along a direction intersecting the extension direction of the first extension portion.

[0107] (17) The instrument according to (16), wherein the second extension portion is cylindrical, and the outer wall surface of the first extension portion has a shape including a first outer peripheral surface having a first radius and a second outer peripheral surface having a second radius, the second radius being smaller than the first radius.

[0108] (18) A method for manufacturing a heat pipe, the heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body, the method comprising the steps of: inserting an instrument extending in an extension direction of the tubular body into the tubular body, filling a gap between the inner wall surface of the tubular body and the outer wall surface of the instrument with metal powder, and forming the sintered body layer in the gap by sintering the metal powder, wherein the gap comprises a first filling region and a second filling region, the second filling region having a larger width in the thickness direction of the tubular body than the first filling region, and the first filling region comprising a region, a portion of which has a large width in the thickness direction of the tubular body.

Claims

1. A heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on an inner wall surface of the tubular body, The heat pipe comprises: an evaporation section in which the working fluid evaporates; a condensation section in which the working fluid is condensed; and an intermediate section positioned between the evaporation section and the condensation section, wherein At least the middle section includes a first thick portion having a first thickness and a second thick portion having a second thickness in a cross section taken along a direction intersecting the extending direction of the heat pipe, the second thickness being greater than the first thickness, The first thick portion and the second thick portion of the middle section face each other at least partially across the center of the tubular body in the cross section, and The second thick portion includes a combination of the tubular body and the sintered body layer.

2. The heat pipe according to claim 1, wherein The first thick portion includes a combination of a tubular body and a sintered body layer.

3. The heat pipe according to claim 1, wherein The first thick portion includes only the tubular body.

4. The heat pipe according to claim 1, wherein At least the evaporation section includes a third thick portion having a third thickness, and The third thick portion includes a combination of the tubular body and the sintered body layer and has a thickness greater than that of the second thick portion.

5. The heat pipe according to claim 4, wherein At least a portion of the middle section located on one side of the evaporation section includes a third thick portion. The heat pipe according to claim 5 , wherein: The third thick portion of the middle section is connected to the third thick portion of the evaporation section.

7. The heat pipe according to claim 1, wherein The condensation section includes a first thick portion and a second thick portion in a cross section taken along a direction intersecting an extending direction of the tubular body.

8. The heat pipe according to claim 7, wherein: The second thick portion of the middle section is connected to the second thick portion of the condensing section.

9. The heat pipe according to claim 1, wherein The sintered body layer on the inner wall surface of the evaporation section is formed over the entire circumference in a cross section taken along a direction intersecting the extending direction of the tubular body.

10. The heat pipe according to claim 9, wherein The sintered body layer of the inner wall surface of the evaporation section is formed over the entire length of the evaporation section in the extending direction of the tubular body.

11. The heat pipe according to claim 1, wherein The thickness of the combination of the tubular body and the sintered body layer gradually decreases from a side of the evaporation section toward a side of the condensation section.

12. An electronic device having a housing, the housing being configured to accommodate: Heat generating components, heat dissipation components, and A heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on an inner wall surface of the tubular body, The heat pipe comprises: an evaporation section in which the working fluid evaporates due to heat from the heat-generating component, a condensation section in which the working fluid is condensed due to the heat dissipation effect of the heat dissipation component, and an intermediate section positioned between the evaporation section and the condensation section, wherein At least the middle section includes a first thick portion having a first thickness and a second thick portion having a second thickness in a cross section taken along a direction intersecting the extending direction of the heat pipe, the second thickness being greater than the first thickness, The first thick portion and the second thick portion of the middle section face each other at least partially across the center of the tubular body in the cross section, and The second thick portion includes a combination of the tubular body and the sintered body layer.

13. The electronic device according to claim 12, wherein: At least a portion of the evaporation section is disposed in contact with a heat-generating component, and At least a portion of the condensing section is disposed in contact with the heat dissipation component.

14. The electronic device according to claim 12, wherein: When the electronic device is in a predetermined usage posture, at least a portion of the second thick portion is configured to be located at the lowermost portion of the heat pipe.

15. The electronic device according to claim 12, wherein: When the electronic device is in a predetermined usage posture, the second thick portion is arranged to be located below the center of the tubular body in the vertical direction.

16. An apparatus for forming a sintered body layer in a heat pipe, the heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on the inner wall surface of the tubular body, The instrument comprises: a first extension portion extending along an extension direction of the tubular body; and a second extending portion extending from an end portion of the first extending portion along an extending direction of the tubular body, wherein a length from a center of the second extension portion to an outer wall surface of the second extension portion in a cross section taken along a direction intersecting the extension direction of the second extension portion is shorter than a length from a center of the first extension portion to an outer wall surface of the first extension portion in a cross section taken along a direction intersecting the extension direction of the first extension portion, and The first extension portion includes a portion having a shorter length from a center thereof to an outer wall surface in a cross section taken in a direction intersecting with an extending direction of the first extension portion.

17. The apparatus of claim 16, wherein: The second extension is cylindrical, and The shape of the outer wall surface of the first extension portion includes a first outer peripheral surface having a first radius and a second outer peripheral surface having a second radius, the second radius being smaller than the first radius.

18. A method for manufacturing a heat pipe, the heat pipe comprising a tubular body in which a working fluid is sealed; and a sintered body layer formed by sintering metal powder on an inner wall surface of the tubular body, The method comprises the following steps: inserting an instrument extending along an extension direction of the tubular body into the tubular body; filling a gap between an inner wall surface of the tubular body and an outer wall surface of the instrument with metal powder; and forming the sintered body layer in the gap by sintering the metal powder, The gap includes a first filling area and a second filling area, The second filling region has a greater width in the thickness direction of the tubular body than the first filling region, and The first filling region includes a region, a portion of which has a large width in the thickness direction of the tubular body.

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