WO2023238626A1

WO2023238626A1 - Heat diffusion device and electronic appliance

Info

Publication number: WO2023238626A1
Application number: PCT/JP2023/018557
Authority: WO
Inventors: 利克大櫃
Original assignee: 株式会社村田製作所
Priority date: 2022-06-08
Filing date: 2023-05-18
Publication date: 2023-12-14
Also published as: CN220776319U; TW202403256A

Abstract

A vapor chamber 1 as an embodiment of this heat diffusion device comprises: a housing 10 having a first inner surface 11a and a second inner surface 12a, which face each other in the thickness direction Z; a working fluid 20 enclosed in the inner space of the housing 10; and a wick 30 disposed in the inner space of the housing 10, the wick 30 including a support 31 which is in contact with the first inner surface 11a and a perforated object 32 which is in contact with the support 31, the edges of the wick 30 being bent so as to approach the first inner surface 11a.

Description

Heat diffusion devices and electronic equipment

TECHNICAL FIELD The present invention relates to heat diffusion devices and electronic equipment.

In recent years, the amount of heat generated has been increasing due to higher integration and higher performance of elements. Furthermore, as products become smaller, the density of heat generation increases, making heat dissipation measures important. This situation is particularly noticeable in the field of mobile terminals such as smartphones and tablets. Graphite sheets and the like are often used as heat countermeasure members, but their heat transport capacity is not sufficient, so the use of various heat countermeasure members is being considered. Among these, the use of a vapor chamber, which is a planar heat pipe, is being considered as a heat diffusion device that can diffuse heat very effectively.

The vapor chamber has a structure in which a working medium (also referred to as working fluid) and a wick that transports the working medium by capillary force are enclosed inside a housing. The working medium absorbs heat from the heat generating elements such as electronic components in the evaporation section, evaporates in the vapor chamber, moves within the vapor chamber, is cooled, and returns to the liquid phase. . The working medium that has returned to the liquid phase moves again to the evaporation section on the heating element side by the capillary force of the wick, and cools the heating element. By repeating this, the vapor chamber can operate independently without external power, and can diffuse heat two-dimensionally at high speed using the latent heat of vaporization and latent heat of condensation of the working medium.

Patent Document 1 discloses a casing including an upper casing sheet and a lower casing sheet facing each other joined at outer edges and having an internal space, a hydraulic fluid sealed in the internal space, and the lower casing. A microchannel arranged in the inner space of the sheet and forming a flow path for the working fluid; a sheet-shaped wick arranged in the inner space of the casing and in contact with the microchannel; A vapor chamber is described in which the contact area between the wick and the microchannel is 5% to 40% of the area of the internal space when viewed in plan.

International Publication No. 2021/229961

In the vapor chamber described in Patent Document 1, the working fluid changes from liquid to gas in the holes of the wick due to heat from a heat source in close contact with the lower housing sheet. In other words, the working fluid constitutes a gas-liquid interface in the holes of the wick. The vaporized working fluid releases heat in the internal space of the housing and returns to liquid form. The working fluid, which has returned to liquid form, moves through the microchannel due to capillary force due to the pores of the wick and is brought close to the heat source again. However, there is room for improvement in terms of widening the vapor space, which is the space in which the working fluid that has vaporized into steam moves, within the internal space of the casing.

Note that the above problem is not limited to vapor chambers, but is a problem common to thermal diffusion devices that can diffuse heat with a configuration similar to that of vapor chambers.

The present invention was made in order to solve the above problems, and an object of the present invention is to provide a heat diffusion device that can widen the vapor space. Furthermore, an object of the present invention is to provide an electronic device equipped with the above-mentioned heat diffusion device.

The heat diffusion device of the present invention includes a casing having a first inner surface and a second inner surface facing each other in the thickness direction, a working medium sealed in an internal space of the casing, and a working medium disposed in the internal space of the casing. a wick, the wick including a support in contact with the first inner surface, and a perforated body in contact with the support, the edge of the wick facing toward the first inner surface. curved so that they are close together.

The electronic device of the present invention includes the heat diffusion device of the present invention.

According to the present invention, it is possible to provide a heat diffusion device that can widen the vapor space. Furthermore, according to the present invention, it is possible to provide an electronic device including the above heat diffusion device.

FIG. 1 is a perspective view schematically showing an example of a heat diffusion device of the present invention. FIG. 2 is an example of a cross-sectional view of the heat diffusion device shown in FIG. 1 taken along line II-II. FIG. 3 is an enlarged view of portion III in FIG. FIG. 4 is an enlarged view showing a modification of portion III in FIG. 2. FIG. FIG. 5 is a partially enlarged cross-sectional view schematically showing an example of a wick constituting the heat diffusion device shown in FIG. 2. FIG. FIG. 6 is a plan view of the wick shown in FIG. 5 viewed from the support body side. FIG. 7 is a partially enlarged sectional view schematically showing a first modification of the wick. FIG. 8 is a partially enlarged sectional view schematically showing a second modification of the wick. FIG. 9 is a partially enlarged sectional view schematically showing a third modification of the wick. FIG. 10A is a partially enlarged sectional view schematically showing a fourth modification of the wick. FIG. 10B is a plan view schematically showing the through hole, the convex portion, and the flow of steam near the convex portion when the wick shown in FIG. 10A is viewed from the perforated body side. FIG. 11 is a partially enlarged sectional view schematically showing a first modified example of the convex portion shown in FIG. 10A. FIG. 12 is a partially enlarged sectional view schematically showing a second modified example of the convex portion shown in FIG. 10A. FIG. 13 is a partially enlarged cross-sectional view schematically showing a third modification of the convex portion shown in FIG. 10A. FIG. 14 is a partially enlarged sectional view schematically showing a fourth modification of the convex portion shown in FIG. 10A. FIG. 15 is a partially enlarged sectional view schematically showing a fifth modification example of the convex portion shown in FIG. 10A. FIG. 16A is a partially enlarged cross-sectional view schematically showing a fifth modification of the wick. FIG. 16B is a cross-sectional view showing an example of a state in which a working medium is enclosed in the cross-sectional view shown in FIG. 16A. FIG. 17 is a partially enlarged sectional view schematically showing a first modified example of the convex portion shown in FIG. 16A. FIG. 18 is a partially enlarged sectional view schematically showing a second modified example of the convex portion shown in FIG. 16A. FIG. 19 is a partially enlarged sectional view schematically showing a third modification of the convex portion shown in FIG. 16A. FIG. 20 is a partially enlarged sectional view schematically showing a fourth modification of the convex portion shown in FIG. 16A. FIG. 21 is a partially enlarged sectional view schematically showing a fifth modification example of the convex portion shown in FIG. 16A. FIG. 22 is a plan view schematically showing a sixth modification of the wick. FIG. 23 is a plan view schematically showing the arrangement of wicks when the heat diffusion device shown in FIG. 1 is viewed from the thickness direction. FIG. 24 is a plan view schematically showing the arrangement of the wicks when the first modified example of the heat diffusion device of the present invention is viewed from the thickness direction. FIG. 25 is a plan view schematically showing the arrangement of the wick when the second modified example of the heat diffusion device of the present invention is viewed from the thickness direction. FIG. 26 is a cross-sectional view schematically showing a third modification of the heat diffusion device. FIG. 27 is a cross-sectional view schematically showing a fourth modification of the heat diffusion device.

The heat diffusion device of the present invention will be explained below.
However, the present invention is not limited to the following embodiments, and can be modified and applied as appropriate without changing the gist of the present invention. Note that the present invention also includes a combination of two or more of the individual preferred configurations of the present invention described below.

Hereinafter, a vapor chamber will be described as an example of an embodiment of the heat diffusion device of the present invention. The heat diffusion device of the present invention is also applicable to heat diffusion devices such as heat pipes.

The drawings shown below are schematic, and their dimensions and aspect ratio may differ from the actual product.

FIG. 1 is a perspective view schematically showing an example of the heat diffusion device of the present invention. FIG. 2 is an example of a cross-sectional view of the heat diffusion device shown in FIG. 1 taken along line II-II.

The vapor chamber (thermal diffusion device) 1 shown in FIGS. 1 and 2 includes a hollow casing 10 that is hermetically sealed. The housing 10 has a first inner surface 11a and a second inner surface 12a facing each other in the thickness direction Z. The vapor chamber 1 further includes a working medium 20 sealed in the internal space of the housing 10 and a wick 30 arranged in the internal space of the housing 10.

The housing 10 is provided with an evaporation section that evaporates the enclosed working medium 20. As shown in FIG. 1, a heat source HS, which is a heat generating element, is arranged on the outer surface of the housing 10. Examples of the heat source HS include electronic components of electronic equipment, such as a central processing unit (CPU). A portion of the internal space of the housing 10 that is near the heat source HS and is heated by the heat source HS corresponds to the evaporation section.

It is preferable that the vapor chamber 1 has a planar shape as a whole. That is, it is preferable that the housing 10 has a planar shape as a whole. Here, "plane shape" includes plate shape and sheet shape, and the dimension in the width direction X (hereinafter referred to as width) and the dimension in the length direction Y (hereinafter referred to as length) is It means a shape that is considerably large relative to its dimensions (hereinafter referred to as thickness or height), for example, a shape whose width and length are 10 times or more, preferably 100 times or more, the thickness.

The size of the vapor chamber 1, that is, the size of the housing 10, is not particularly limited. The width and length of the vapor chamber 1 can be set as appropriate depending on the application. The width and length of the vapor chamber 1 are, for example, 5 mm or more and 500 mm or less, 20 mm or more and 300 mm or less, or 50 mm or more and 200 mm or less. The width and length of the vapor chamber 1 may be the same or different.

It is preferable that the casing 10 is composed of a first sheet 11 and a second sheet 12 that are joined at their outer edges and that face each other in the thickness direction Z. The first sheet 11 has the first inner surface 11a of the housing 10. The second sheet 12 has a second inner surface 12a of the housing 10. The first sheet 11 and the second sheet 12 are joined at their outer edges by a joint 13 .

When the housing 10 is composed of the first sheet 11 and the second sheet 12, the materials constituting the first sheet 11 and the second sheet 12 have properties suitable for use as a vapor chamber, such as thermal conductivity and strength. It is not particularly limited as long as it has flexibility, softness, etc. The material constituting the first sheet 11 and the second sheet 12 is preferably a metal, such as copper, nickel, aluminum, magnesium, titanium, iron, or an alloy containing these as main components, and particularly preferably copper. It is. The materials constituting the first sheet 11 and the second sheet 12 may be the same or different, but are preferably the same.

When the housing 10 is composed of the first sheet 11 and the second sheet 12, the outer edges of the first sheet 11 and the second sheet 12 are joined by the joining part 13. The method of such joining is not particularly limited, but for example, laser welding, resistance welding, diffusion bonding, brazing welding, TIG welding (tungsten-inert gas welding), ultrasonic bonding, or resin sealing can be used, and preferably Laser welding, resistance welding or brazing can be used.

The thickness of the first sheet 11 and the second sheet 12 is not particularly limited, but each is preferably 10 μm or more and 200 μm or less, more preferably 30 μm or more and 100 μm or less, and even more preferably 40 μm or more and 60 μm or less. The thickness of the first sheet 11 and the second sheet 12 may be the same or different. Further, the thickness of each of the first sheet 11 and the second sheet 12 may be the same over the entirety, or may be partially thin.

The shapes of the first sheet 11 and the second sheet 12 are not particularly limited. For example, each of the first sheet 11 and the second sheet 12 may have an outer edge portion thicker than a portion other than the outer edge portion.

At the joining portion 13, the first sheet 11 and the second sheet 12 are joined. There may be a mark in the joint portion 13 where the first sheet 11 and the second sheet 12 were joined.

The overall thickness of the vapor chamber 1 is not particularly limited, but is preferably 50 μm or more and 500 μm or less.

The planar shape of the casing 10 viewed from the thickness direction Z is not particularly limited, and examples thereof include polygons such as triangles and rectangles, circles, ellipses, and combinations thereof. Further, the planar shape of the casing 10 may be an L-shape, a C-shape (U-shape), a staircase shape, or the like. Furthermore, the housing 10 may have a through hole. The planar shape of the casing 10 may be a shape depending on the purpose of the vapor chamber, the shape of the part where the vapor chamber is installed, and other components existing nearby.

The working medium 20 is not particularly limited as long as it can cause a gas-liquid phase change in the environment inside the casing 10, and for example, water, alcohols, CFC substitutes, etc. can be used. For example, working medium 20 is an aqueous compound, preferably water.

The wick 30 has a capillary structure that can move the working medium 20 by capillary force. The capillary structure of the wick 30 may be a known structure used in conventional vapor chambers.

Although the size and shape of the wick 30 are not particularly limited, it is preferable, for example, that the wick 30 be arranged continuously in the internal space of the housing 10. The wick 30 may be disposed in the entire internal space of the casing 10 when viewed from the thickness direction Z, or the wick 30 may be disposed in a part of the internal space of the casing 10 when viewed from the thickness direction Z. You can leave it there. An example of the arrangement of the wicks in the internal space of the housing 10 will be described later using FIGS. 23, 24, and 25.

As shown in FIG. 2, the wick 30 includes a support 31 in contact with the first inner surface 11a and a perforated body 32 in contact with the support 31.

FIG. 3 is an enlarged view of portion III in FIG. 2. FIG. 3 is an enlarged view showing the periphery of the edge of the wick 30.

FIG. 4 is an enlarged view showing a modification of portion III in FIG. 2.

The edge of the wick 30 is bent toward the first inner surface 11a side. The edge of the wick 30 is bent downward in FIGS. 3 and 4. In the wick 30 shown in FIGS. 3 and 4, the edge of the perforated body 32 is bent toward the first inner surface 11a side.

If the edge of the wick 30 is bent toward the first inner surface 11a side, the space on the second inner surface 12a side will be smaller than the edge of the wick 30, compared to a wick with an uncurved edge. Since it can be expanded, it is possible to widen the steam space, which is the space in which the working medium 20 that has been vaporized and turned into steam moves. Specifically, in the wick 30, the area indicated by R in FIGS. 3 and 4 can be expanded as a vapor space, compared to a wick whose edge is not bent toward the first inner surface 11a side. can. By widening the vapor space, the thermal conductivity of the vapor chamber 1 can be improved.

The edge of the wick 30 may be bent toward the first inner surface 11a by, for example, press working. When the wick 30 is made of a porous sintered body such as a ceramic porous sintered body, the edge of the wick 30 is formed by printing a paste material, performing press working, and then firing. may be bent so as to approach the first inner surface 11a side. Alternatively, the edge of the wick 30 approaches the first inner surface 11a by preparing a thicker porous sintered body in advance and removing a portion of the porous sintered body by etching or the like. It may be bent like this.

The shape of the edge of the wick 30 is not particularly limited as long as it is curved toward the first inner surface 11a side.

In the example shown in FIGS. 3 and 4, the edge of the wick 30 is curved in a cross section along the thickness direction Z so as to approach the first inner surface 11a side. In this case, the edge of the wick 30 preferably has a convex shape toward the second inner surface 12a (upper side), as shown in FIGS. 3 and 4. When the edge of the wick 30 is curved in a cross section along the thickness direction Z, the edge may be curved so that the curvature is constant, or may be curved while changing the curvature. Further, the edge of the wick 30 may be bent linearly at a predetermined position so as to approach the first inner surface 11a side in the cross section along the thickness direction Z.

As shown in FIG. 3, in a cross section along the thickness direction Z, it is preferable that a gap exist between the edge of the wick 30 and the inner edge of the casing 10 in a direction perpendicular to the thickness direction Z. . That is, in the cross section along the thickness direction Z, it is preferable that the edge of the wick 30 and the inner edge of the housing 10 do not touch. Hereinafter, in the cross section along the thickness direction Z, the effect of the gap existing in the direction perpendicular to the thickness direction Z between the edge of the wick 30 and the inner edge of the casing 10 will be explained.

In the vapor chamber 1, in a portion of the vapor space near the inner edge of the casing 10, the working medium 20, which is in the form of vapor, comes into contact with the inner edge of the casing 10 and easily becomes liquid. Therefore, in the cross section along the thickness direction Z, if the edge of the wick 30 and the inner edge of the casing 10 are in contact, the steam space near the part where the edge of the wick 30 and the inner edge of the casing 10 are in contact with each other. There is a risk that the vapor space will become narrow due to the accumulation of liquid working medium 20 in the space. On the other hand, if a gap exists in the direction perpendicular to the thickness direction Z between the edge of the wick 30 and the inner edge of the casing 10 in the cross section along the thickness direction Z, the liquid working medium 20 can move into the liquid flow path through the gap between the edge of the wick 30 and the inner edge of the casing 10, so the liquid working medium 20 accumulates in the vapor space, causing the vapor space to become narrow. can be prevented.

The distance between the edge of the wick 30 and the inner edge of the housing 10 (the length indicated by A in FIG. 3) is preferably 10 μm or more, for example. If the distance between the edge of the wick 30 and the inner edge of the housing 10 (the length indicated by A in FIG. 3) is 10 μm or more, the liquid working medium 20 accumulates in the vapor space, resulting in a narrow vapor space. This can be prevented more efficiently. On the other hand, the distance between the edge of the wick 30 and the inner edge of the housing 10 (the length indicated by A in FIG. 3) is preferably 500 μm or less.

As shown in FIG. 4, in the cross section along the thickness direction Z, there is no gap between the edge of the wick 30 and the inner edge of the casing 10 in the direction perpendicular to the thickness direction Z. good. In FIG. 4, the edge of the wick 30 and the inner edge of the housing 10 are in contact. Note that when the edge of the wick 30 and the inner edge of the housing 10 are in contact with each other as shown in FIG. 4, the distance between the edge of the wick 30 and the inner edge of the housing 10 is 0 μm.

The bending height of the edge of the wick 30 (distance indicated by B in FIG. 3), which is the distance in the thickness direction Z between the edge of the wick 30 and a portion of the wick 30 other than the edge, is particularly limited. However, it may be, for example, 1 μm or more and 100 μm or less.

The length of the wick in the direction perpendicular to the thickness direction Z at the portion where the edge of the wick 30 is bent toward the first inner surface 11a side in a cross section along the thickness direction Z. The bending width of the edge 30 (the length indicated by C in FIG. 3) is not particularly limited, but may be, for example, 1 μm or more and 1000 μm or less. In FIG. 3, the bending width of the edge of the wick 30 is the length in the width direction X.

Only a part of the edge of the wick 30 may be bent toward the first inner surface 11a, but from the viewpoint of widening the vapor space, the entire edge of the wick 30 is bent toward the first inner surface 11a. It is preferable that it curves toward the 11a side.

It is preferable that the joint 13 between the first sheet 11 and the second sheet 12 be located at a different position from the edge of the wick 30 in the thickness direction Z. If the joint 13 between the first sheet 11 and the second sheet 12 is located at the same position as the edge of the wick 30 in the thickness direction Z, the first sheet 11 and the second sheet 12 will be connected in the manufacturing process of the vapor chamber. When joining, the part that functions as the wick 30 is reduced by entering the wick 30 into the joint part 13, so there is a risk that the maximum heat transport amount will decrease. On the other hand, if the joint 13 between the first sheet 11 and the second sheet 12 is located at a different position from the edge of the wick 30 in the thickness direction Z, the edge of the wick 30 will enter the joint 13. Therefore, it is possible to prevent the maximum heat transport amount from decreasing in the vapor chamber 1.

3 and 4, the joint 13 between the first sheet 11 and the second sheet 12 is located between the edge of the wick 30 and the second inner surface 12a of the casing 10 in the thickness direction Z. However, the edge of the wick 30 may be located between the joint 13 of the first sheet 11 and the second sheet 12 and the second inner surface 12a of the housing 10 in the thickness direction Z.

FIG. 5 is a partially enlarged sectional view schematically showing an example of a wick that constitutes the heat diffusion device shown in FIG. 2. FIG. 6 is a plan view of the wick shown in FIG. 5 viewed from the support body side.

In the wick 30, a support 31 is formed in the recessed part by bending and recessing a part of the metal foil by, for example, press working. Since a vapor space is formed in the recessed portion of the support body 31, thermal conductivity is improved. In addition to the example shown in FIG. 5, when pressing metal foil, a through hole may be formed in a recessed portion when a part of the metal foil is bent, depending on the condition of the pressing.

It is preferable that the thickness of the metal foil is constant before performing press working or the like. However, the metal foil may become thinner in bent areas. From the above, in the wick 30, it is preferable that the thickness of the support body 31 is the same as the thickness of the porous body 32, or smaller than the thickness of the porous body 32.

In the wick 30, the porous body 32 is made of the same material as the support body 31.

In the wick 30, the support body 31 and the perforated body 32 are integrally constructed. In this specification, "the support body 31 and the porous body 32 are integrally constituted" means that there is no interface between the support body 31 and the porous body 32, and specifically, , which means that the boundary between the support body 31 and the porous body 32 cannot be determined.

In the wick 30, the support body 31 includes a plurality of columnar members, for example, as shown in FIG. By retaining the liquid phase working medium 20 between the columnar members, the heat transport performance of the vapor chamber 1 can be improved. Here, "columnar" means a shape in which the ratio of the length of the long side of the bottom surface is less than 5 times the length of the short side of the bottom surface.

The shape of the columnar member is not particularly limited, and examples include shapes such as a columnar shape, a prismatic shape, a truncated cone shape, and a truncated pyramid shape.

The shape of the support body 31 is not particularly limited, but as shown in FIGS. 2 and 5, the support body 31 preferably has a tapered shape whose width becomes narrower from the perforated body 32 toward the first inner surface 11a. Thereby, the flow path between the supports 31 can be widened on the first inner surface 11a side of the housing 10 while suppressing the perforated body 32 from falling into the spaces between the supports 31. As a result, the transmittance increases and the maximum heat transport amount increases.

The arrangement of the supports 31 is not particularly limited, but is preferably arranged evenly in a predetermined area, more preferably evenly throughout, for example, so that the center-to-center distance (pitch) of the supports 31 is constant.

The center-to-center distance of the support body 31 (the length indicated by P ₃₁ in FIG. 6) is, for example, 60 μm or more and 800 μm or less. The width of the support body 31 (the length indicated by W ₃₁ in FIG. 6) is, for example, 20 μm or more and 500 μm or less. The height of the support body 31 (the length indicated by T ₃₁ in FIG. 5) is, for example, 10 μm or more and 100 μm or less. The equivalent circle diameter of the cross section perpendicular to the height direction of the support body 31 is, for example, 20 μm or more and 500 μm or less.

In the example shown in FIG. 5, the bending height of the edge of the wick 30 (the distance indicated by B in FIG. 5) is smaller than the height of the support 31 (the length indicated by T ₃₁ in FIG. 5).

The bending width of the edge of the wick 30 (distance indicated by C in FIGS. 5 and 6) may be smaller or larger than the width of the support 31 (length indicated by W ₃₁ in FIG. 6). Well, they can be the same.

In the wick 30, the perforated body 32 may have a through hole 33 penetrating in the thickness direction Z. Within the through hole 33, the working medium 20 can move due to capillary action. It is preferable that the through hole 33 is provided in a portion where the support body 31 is not present when viewed from the thickness direction Z. Although the shape of the through hole 33 is not particularly limited, it is preferable that the cross section in a plane perpendicular to the thickness direction Z is circular or elliptical.

The arrangement of the through holes 33 of the perforated body 32 is not particularly limited, but is preferably arranged uniformly in a predetermined area, more preferably evenly over the entire area, for example, by adjusting the center-to-center distance (pitch) of the through holes 33 of the perforated body 32. are arranged so that it is constant.

The distance between the centers of the through holes 33 of the porous body 32 (the length indicated by P ₃₃ in FIG. 6) is, for example, 3 μm or more and 150 μm or less. The diameter of the through hole 33 (the length indicated by φ ₃₃ in FIG. 6) is, for example, 100 μm or less. The thickness of the porous body 32 (the length indicated by T ₃₂ in FIG. 5) is, for example, 5 μm or more and 50 μm or less.

The bending height of the edge of the wick 30 (the distance indicated by B in FIG. 5) may be smaller than or greater than the thickness of the perforated body 32 (the length indicated by T ₃₂ in FIG. 5). Well, they can be the same.

The bending width of the edge of the wick 30 (distance indicated by C in FIGS. 5 and 6) may be smaller or larger than the diameter of the through hole 33 (length indicated by φ ₃₃ in FIG. 6). Well, they can be the same.

The through-hole 33 can be made, for example, by punching the metal or the like that constitutes the perforated body 32 by press working. The wick 30 may be formed by simultaneously performing the press work for forming the support body 31 and the press work for forming the through holes 33.

As shown in FIG. 2, the vapor chamber 1 may further include a support 40 disposed in the internal space so as to be in contact with the second inner surface 12a of the housing 10. It is possible to support the housing 10 and the wick 30 by arranging the struts 40 in the internal space of the housing 10.

The material constituting the pillar 40 is not particularly limited, and examples thereof include resin, metal, ceramics, a mixture thereof, a laminate, and the like. Further, the support column 40 may be integrated with the housing 10, and may be formed by, for example, etching the second inner surface 12a of the housing 10.

The shape of the support 40 is not particularly limited as long as it can support the housing 10 and the wick 30, but the shape of the cross section perpendicular to the height direction of the support 40 may be, for example, a polygon such as a rectangle, a circle, or an ellipse. Examples include shape.

The heights of the columns 40 may be the same or different in one vapor chamber.

The height of the pillar 40 may be, for example, 50 μm or more and 1000 μm or less.

The height of the support column 40 is preferably greater than the height of the support body 31.

In the cross section shown in FIG. 2, the width of the support 40 is not particularly limited as long as it provides strength that can suppress deformation of the casing 10, but the width is the equivalent circle diameter of the cross section perpendicular to the height direction of the end of the support 40. is, for example, 100 μm or more and 2000 μm or less, preferably 300 μm or more and 1000 μm or less. By increasing the equivalent circular diameter of the support column 40, deformation of the housing 10 can be further suppressed. On the other hand, by reducing the equivalent circle diameter of the support column 40, it is possible to secure a wider space for the vapor of the working medium 20 to move.

The equivalent circle diameter of the cross section perpendicular to the height direction of the support 40 is preferably larger than the equivalent circle diameter of the cross section perpendicular to the height direction of the support body 31.

The arrangement of the struts 40 is not particularly limited, but is preferably arranged evenly in a predetermined area, more preferably evenly throughout, for example, so that the distance between the struts 40 is constant. By arranging the pillars 40 evenly, uniform strength can be ensured throughout the vapor chamber 1.

The center-to-center distance between adjacent pillars 40 may be, for example, 100 μm or more and 5000 μm or less.

It is preferable that the center-to-center distance between mutually adjacent support columns 40 is larger than the center-to-center distance between mutually adjacent supports 31. When the support body 31 includes a plurality of columnar members, it is preferable that the center-to-center distance between the mutually adjacent columns 40 is larger than the center-to-center distance between the mutually adjacent columnar members.

FIG. 7 is a partially enlarged sectional view schematically showing a first modification of the wick.

Note that in the cross-sectional views shown in FIGS. 7 to 9, the edges of the wick are not shown in order to simplify the explanation of the modified examples of the wick. The shape of the edge of the wick in the cross-sectional views shown in FIGS. 7 to 9 may be the same as the shape of the edge of the wick 30 in the cross-sectional view shown in FIG.

In the wick 30A shown in FIG. 7, the support 31 is not recessed.

In the wick 30A shown in FIG. 7, the porous body 32 is made of the same material as the support body 31. In the case where the porous body 32 is made of the same material as the support body 31, the materials constituting the support body 31 and the porous body 32 are not particularly limited, but may include, for example, resin, metal, ceramics, or a mixture thereof; Examples include laminates. The material constituting the support body 31 and the porous body 32 is preferably metal.

In the wick 30A, the support body 31 and the perforated body 32 may be integrally configured.

The wick 30A in which the support body 31 and the porous body 32 are integrally formed can be produced by, for example, an etching technique, a printing technique using multilayer coating, or another multilayer technique.

In the wick 30A, when the porous body 32 is made of the same material as the support body 31, the support body 31 and the porous body 32 do not need to be integrally constituted. For example, in a wick 30A in which a copper pillar as a support 31 and a copper mesh as a perforated body 32 are fixed by diffusion bonding or spot welding, the entire surface between the support 31 and the perforated body 32 is fixed. Since it is difficult to join the support body 31 and the porous body 32, a gap is formed between the support body 31 and the porous body 32. In such a wick 30A, the boundary between the support body 31 and the perforated body 32 can be distinguished, so that although the perforated body 32 is made of the same material as the support body 31, It is not constructed integrally with the body 32.

FIG. 8 is a partially enlarged sectional view schematically showing a second modification of the wick.

In the wick 30B shown in FIG. 8, the support body 31 is not recessed.

In the wick 30B shown in FIG. 8, the support 31 and the porous body 32 are made of a porous body. By forming not only the porous body 32 but also the support body 31 from a porous body, the capillary force of the wick 30B can be improved.

The porous bodies constituting the support body 31 and the porous body 32 include, for example, porous sintered bodies such as metal porous sintered bodies and ceramic porous sintered bodies, or metal porous bodies, ceramic porous bodies, Examples include porous bodies such as porous resin bodies.

The wick 30B made of a porous material can be produced, for example, by a printing technique using multilayer coating using metal paste or ceramic paste. At this time, the content of metal or ceramics in the paste for forming the support body 31 may be the same as the content of metal or ceramics in the paste for forming the porous body 32. The content of metal or ceramics in the paste for forming the porous body 32 may be smaller than the content of metal or ceramics in the paste for forming the porous body 32. For example, by making the content of metal or ceramics in the paste for forming the support body 31 larger than the content of metal or ceramics in the paste for forming the porous body 32, The density can be made larger than the density of the porous body 32. As a result, the strength of the support body 31 can be increased.

The porous body 32 made of a porous body may have through holes penetrating in the thickness direction Z. The porous body 32 made of a porous body does not need to have through holes penetrating in the thickness direction Z.

FIG. 9 is a partially enlarged sectional view schematically showing a third modification of the wick.

In the wick 30C shown in FIG. 9, the support body 31 is not recessed.

In the wick 30C shown in FIG. 9, the porous body 32 is made of a different material from the support body 31.

When the support body 31 and the porous body 32 are made of different materials, the material constituting the support body 31 is not particularly limited, and examples thereof include resin, metal, ceramics, a mixture thereof, a laminate, etc. It will be done. The material constituting the porous body 32 is not particularly limited, and examples thereof include resin, metal, ceramics, a mixture thereof, a laminate, and the like.

The wick 30C in which the support body 31 and the porous body 32 are made of different materials can be produced, for example, by a printing technique using multilayer coating using metal paste or ceramic paste.

When the perforated body 32 is made of a material different from that of the support 31, the support 31 and the perforated body 32 may be fixed by diffusion bonding, spot welding, or the like.

In the wick 30C, for example, the porous body 32 is made of a porous body.

Examples of the porous body constituting the porous body 32 include a porous sintered body such as a porous metal sintered body, a porous ceramic sintered body, a porous metal body, a porous ceramic body, a porous resin body, etc. Examples include porous bodies.

The porous body 32 made of a porous body may have through holes 33 penetrating in the thickness direction Z. The porous body 32 made of a porous body does not need to have through holes 33 penetrating in the thickness direction Z.

FIG. 10A is a partially enlarged cross-sectional view schematically showing a fourth modification of the wick. FIG. 10B is a plan view schematically showing the through hole, the convex portion, and the flow of steam near the convex portion when the wick shown in FIG. 10A is viewed from the perforated body side.

In the wick 30D shown in FIG. 10A, a protrusion 34 is provided on the periphery of the through hole 33 in a direction approaching the second inner surface 12a.

The convex portion 34 has a first end 35 on the first inner surface 11a side and a second end 36 on the second inner surface 12a side.

Hereinafter, the effect of providing the convex portion 34 on the periphery of the through hole 33 in a direction approaching the second inner surface 12a will be explained. The working medium 20 evaporated in the heat source HS flows in a vapor state through the space between the perforated body 32 and the second inner surface 12a in a direction away from the heat source HS. As shown in FIG. 10B, if a convex portion 34 is provided at the periphery of the through hole 33 in a direction approaching the second inner surface 12a, steam flowing in the space between the perforated body 32 and the second inner surface 12a flows around the outer peripheral edge of the convex portion 34. Therefore, the flow of steam can be prevented from coming into direct contact with the liquid level of the working medium 20 in the through hole 33. Therefore, the influence of the flow of steam in the opposite direction to the capillary force of the wick 30, that is, the so-called counterflow, can be reduced. Therefore, the maximum heat transport amount of the vapor chamber 1 can be improved.

It is preferable that the convex portion 34 is provided on the entire periphery of the through hole 33. The protrusion 34 may be provided only on a part of the periphery of the through hole 33.

The convex portion 34 may be provided on the periphery of all the through holes 33 in the perforated body 32, or may be provided only on the periphery of some of the through holes 33 in the perforated body 32. When the convex portion 34 is provided only on the periphery of some of the through holes 33 in the perforated body 32, the convex portion 34 may be provided on the periphery of the through holes 33 other than those located directly above the heat source HS. preferable.

The through holes 33 and the convex portions 34 can be produced, for example, by punching the metal or the like that constitutes the perforated body 32 by press working. In punching by press working, the shape of the convex portion, etc. can be adjusted by appropriately adjusting the punching depth, etc. Note that the punching depth means, for example, how far the punch is pushed in the punching direction when punching is performed.

The dimensions of the convex portion 34 are not particularly limited. For example, the height of the protrusion 34 may be larger than the diameter of the through hole 33, the height of the protrusion 34 may be smaller than the diameter of the through hole 33, and the height of the protrusion 34 may be It may be the same as the diameter of the through hole 33. In addition, in the convex part 34 shown in FIG. 10A, the height of the convex part 34 means the distance in the thickness direction Z between the 1st end part 35 and the 2nd end part 36.

In the example shown in FIG. 10A, the bending height of the edge of the wick 30D (distance indicated by B in FIG. 10A) is greater than the height of the convex portion 34. The bending height of the edge of the wick 30D (the distance indicated by B in FIG. 10A) may be smaller than the height of the protrusion 34, or may be the same as the height of the protrusion 34.

Note that when a protrusion 34 is provided at the peripheral edge of the through hole 33 in a direction approaching the second inner surface 12a, the thickness of the perforated body 32 is equal to the thickness of the perforated body 32 at the portion where the protrusion 34 is not provided. It means the thickness of the body 32.

In the wick 30D shown in FIG. 10A, a support body 31 is formed in the recessed part by bending and recessing a part of the metal foil by pressing or the like. The wick 30D may be formed by simultaneously performing the press work to form the support body 31 and the press work to form the through holes 33 and the convex portions 34.

In the wick 30D shown in FIG. 10A, the support 31 does not have to be recessed like the wick 30A shown in FIG. 7, the wick 30B shown in FIG. 8, and the wick 30C shown in FIG.

FIG. 11 is a partially enlarged cross-sectional view schematically showing a first modification of the convex portion shown in FIG. 10A.

Note that in the cross-sectional views shown in FIGS. 11 to 15, the edges of the wick are not shown in order to simplify the explanation of the modified examples of the wick. The shape of the edge of the wick in the cross-sectional views shown in FIGS. 11 to 15 may be the same as the shape of the edge of the wick 30D in the cross-sectional view shown in FIG. 10A.

The convex portion 34a shown in FIG. 11 has a first end 35a on the first inner surface 11a side and a second end 36a on the second inner surface 12a side. In the convex portion 34a, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the second end portion 36a is smaller than the cross-sectional area of the region surrounded by the inner wall of the first end portion 35a. When the cross-sectional area of the region surrounded by the inner wall of the second end 36 a is smaller than the cross-sectional area of the region surrounded by the inner wall of the first end 35 a when viewed from the thickness direction Z, the flow of steam inside the through-hole 33 is Direct contact with the liquid surface of the working medium 20 can be further prevented. As a result, the influence of counterflow can be further reduced, so that the maximum heat transport amount of the vapor chamber 1 can be further improved.

In the convex portion 34a, when viewed from the thickness direction Z, the inner wall of the second end portion 36a is located inside the inner wall of the first end portion 35a. When the inner wall of the second end 36a is located inside the inner wall of the first end 35a when viewed from the thickness direction Z, the flow of steam directly contacts the liquid level of the working medium 20 in the through hole 33. can be further prevented. As a result, the influence of counterflow can be further reduced, so that the maximum heat transport amount of the vapor chamber 1 can be further improved.

In the cross section along the thickness direction Z, the convex portion 34a has a tapered shape in which the distance between the outer walls of the convex portion 34a becomes narrower toward the second inner surface 12a. When the convex portion 34a has a tapered shape in which the distance between the outer walls of the convex portion 34a becomes narrower toward the second inner surface 12a in the cross section along the thickness direction Z, the distance between the perforated body 32 and the second inner surface increases. 12a, when the steam flows in the space between the convex portion 34a and the convex portion 34a, the steam not only flows around the convex portion 34a but also flows along the outer wall surface of the convex portion 34a in the cross section along the thickness direction Z. Thus, the water can flow toward the second inner surface 12a. Therefore, in the cross section along the thickness direction Z, the protrusion 34a is smaller than the protrusion 34 which does not have a tapered shape in which the distance between the outer walls of the protrusion 34a becomes narrower toward the second inner surface 12a. It is possible to increase the number of paths through which steam comes into contact with. Thereby, a decrease in thermal conductivity of the vapor chamber 1 can be suppressed.

The convex portion 34a has a shape that is convex toward the second inner surface 12a side (upper side in FIG. 11) in a cross section along the thickness direction Z. In other words, the convex portion 34a has a shape that curves toward the second inner surface 12a side (upper side in FIG. 11) with respect to the line segment connecting the first end portion 35a and the second end portion 36a in the cross section along the thickness direction Z. It is.

FIG. 12 is a partially enlarged cross-sectional view schematically showing a second modification of the convex portion shown in FIG. 10A.

The convex portion 34b shown in FIG. 12 has a first end 35b on the first inner surface 11a side and a second end 36b on the second inner surface 12a side. The convex portion 34b has a tapered shape in a cross section along the thickness direction Z such that the distance between the outer walls of the convex portion 34b decreases toward the second inner surface 12a. The convex portion 34b has a shape that is convex toward the first inner surface 11a side (lower side in FIG. 12) in a cross section along the thickness direction Z. In other words, the convex portion 34b curves toward the first inner surface 11a side (downward in FIG. 12) with respect to the line segment connecting the first end portion 35b and the second end portion 36b in the cross section along the thickness direction Z. It is the shape. When the convex portion 34b has a shape that is convex toward the first inner surface 11a side (lower side in FIG. 12) in the cross section along the thickness direction Z, it has a convex shape toward the second inner surface 12a side (upper side in FIG. 11). Compared to the shape of the convex portion 34a, the slope of the outer wall surface of the portion of the convex portion 34b on the first end 35b side is gentle. Therefore, when the steam flowing in the space between the perforated body 32 and the second inner surface 12a comes into contact with the first end 35b side portion of the convex portion 34b, the convex portion 34b is removed in the cross section along the thickness direction Z. It becomes easier to flow toward the second inner surface 12a side along the outer wall surface. Thereby, a decrease in the thermal conductivity of the vapor chamber 1 can be further suppressed.

FIG. 13 is a partially enlarged sectional view schematically showing a third modification of the convex portion shown in FIG. 10A.

The convex portion 34c shown in FIG. 13 has a first end 35c on the first inner surface 11a side and a second end 36c on the second inner surface 12a side. In the convex portion 34c, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the second end portion 36c is smaller than the cross-sectional area of the region surrounded by the inner wall of the first end portion 35c. The convex portion 34c includes a lid portion 37 that narrows the opening of the convex portion 34c at the second end portion 36c. In the convex portion 34c, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the second end portion 36c is narrower than that of the convex portion 34b in which the lid portion 37 does not exist at the second end portion 36c. There is. If the convex portion 34c is provided with a lid portion 37 that narrows the opening of the convex portion 34c at the second end 36c, direct contact of the flow of steam with the liquid level of the working medium 20 in the through hole 33 can be further prevented. I can do it. As a result, the influence of counterflow can be further reduced, so that the maximum heat transport amount of the vapor chamber 1 can be further improved.

The lid portion 37 that narrows the opening of the convex portion 34c may be formed by, for example, performing press working on the second end portion 36c. The size and shape of the lid part 37 that narrows the opening of the convex part 34c are not particularly limited, as long as the opening on the second end 36c side of the convex part 34c is narrowed. It is preferable that the lid portion 37 that narrows the opening of the convex portion 34c has a flat surface. The lid portion 37 that narrows the opening of the convex portion 34c is preferably a flat surface perpendicular to the thickness direction Z. The lid portion 37 that narrows the opening of the convex portion 34c may have a curved surface in part or in its entirety. The lid portion 37 that narrows the opening of the convex portion 34c may have an uneven surface. The thickness of the lid portion 37 that narrows the opening of the convex portion 34c may be the same as or different from the thickness of the convex portion 34c.

FIG. 14 is a partially enlarged sectional view schematically showing a fourth modification of the convex portion shown in FIG. 10A.

The convex portion 34d shown in FIG. 14 has a first end 35d on the first inner surface 11a side and a second end 36d on the second inner surface 12a side. In the convex portion 34d, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the second end portion 36d is larger than the cross-sectional area of the region surrounded by the inner wall of the first end portion 35d.

In the convex portion 34d, when viewed from the thickness direction Z, the inner wall of the second end portion 36d is located outside the inner wall of the first end portion 35d.

FIG. 15 is a partially enlarged sectional view schematically showing a fifth modification of the convex portion shown in FIG. 10A.

The convex portion 34e shown in FIG. 15 has a first end 35e on the first inner surface 11a side and a second end 36e on the second inner surface 12a side. In the convex portion 34e, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the second end portion 36e is larger than the cross-sectional area of the region surrounded by the inner wall of the first end portion 35e. The convex portion 34e includes a lid portion 37 that narrows the opening of the convex portion 34e at the second end portion 36e. In the convex portion 34e, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the second end portion 36e is narrower than that of the convex portion 34d in which the lid portion 37 does not exist at the second end portion 36e. There is. If the convex portion 34e is provided with a lid portion 37 that narrows the opening of the convex portion 34e at the second end 36e, direct contact of the flow of steam with the liquid level of the working medium 20 in the through hole 33 can be further prevented. I can do it. As a result, the influence of counterflow can be further reduced, so that the maximum heat transport amount of the vapor chamber 1 can be further improved.

The lid portion 37 that narrows the opening of the convex portion 34e may be formed, for example, by pressing the second end portion 36e. The size and shape of the lid 37 that narrows the opening of the convex portion 34e are not particularly limited, as long as the opening on the second end 36e side of the convex portion 34e is narrowed. It is preferable that the lid portion 37 that narrows the opening of the convex portion 34e has a flat surface. The lid portion 37 that narrows the opening of the convex portion 34e is preferably a flat surface perpendicular to the thickness direction Z. The lid portion 37 that narrows the opening of the convex portion 34e may have a curved surface in part or in its entirety. The lid portion 37 that narrows the opening of the convex portion 34e may have an uneven surface. The thickness of the lid portion 37 that narrows the opening of the convex portion 34e may be the same as or different from the thickness of the convex portion 34e.

FIG. 16A is a partially enlarged cross-sectional view schematically showing a fifth modification of the wick. FIG. 16B is a cross-sectional view showing an example of a state in which a working medium is enclosed in the cross-sectional view shown in FIG. 16A.

Note that in the cross-sectional views shown in FIGS. 16B and 17 to 21, the edges of the wick are not shown in order to simplify the explanation of the modified examples of the wick. The shape of the edge of the wick in the cross-sectional views shown in FIGS. 16B and 17 to 21 may be the same as the shape of the edge of the wick 30E in the cross-sectional view shown in FIG. 16A.

In the wick 30E shown in FIG. 16A, a protrusion 34f is provided on the periphery of the through hole 33 in a direction approaching the first inner surface 11a.

The convex portion 34f has a first end 35f on the first inner surface 11a side and a second end 36f on the second inner surface 12a side.

Hereinafter, the effect of the protrusion 34f being provided at the periphery of the through hole 33 in a direction approaching the first inner surface 11a will be explained. In FIG. 16B, the working medium 20 is sucked up into the through hole 33 by capillary force by contacting the surface surrounded by the inner wall of the convex portion 34f. Therefore, even though the liquid level of the working medium 20 is located closer to the first inner surface 11a than the perforated body 32 in the portion where the through hole 33 does not exist when the wick 30E is viewed from the thickness direction Z. The working medium 20 is sucked up into the through hole 33 . In this way, even when the amount of the working medium 20 is small as shown in FIG. 16B, the working medium 20 can be sucked up into the through hole 33. Therefore, even if the amount of the working medium 20 is small, it is possible to prevent capillary force from occurring in the wick 30E. From the above, in the vapor chamber 1, even when the amount of the working medium 20 is small, it is possible to suppress the deterioration of the heat soaking performance and the heat transport performance.

When the convex portion 34f is provided on the periphery of the through hole 33 in a direction close to the first inner surface 11a, even when the amount of the working medium 20 is small, deterioration in heat soaking performance and heat transport performance can be suppressed. For example, changes in the design value of the amount of the working medium 20 injected in the manufacturing process, variations in the amount of the working medium 20 injected in the manufacturing process, fluctuations in the amount of the working medium 20 during use, etc. There is little effect on soaking performance or heat transport performance. In other words, if the convex portion 34f is provided on the periphery of the through hole 33 in a direction approaching the first inner surface 11a, it can be said that the robustness against the amount of the working medium 20 in the vapor chamber 1 is improved.

It is preferable that the convex portion 34f is provided on the entire periphery of the through hole 33. The convex portion 34f may be provided only on a part of the periphery of the through hole 33 as long as the convex portion 34f has a shape that allows the working medium 20 to be sucked up by capillary force.

The convex portion 34f may be provided on the periphery of all the through holes 33 in the perforated body 32, or may be provided only on the periphery of some of the through holes 33 in the perforated body 32. When the convex portion 34f is provided only on the periphery of some of the through holes 33 in the perforated body 32, the convex portion 34f is provided at least on the periphery of the through hole 33 located directly above the heat source HS. is preferred. When the convex portion 34f is provided in the through hole 33 located directly above the heat source HS, even if the amount of the working medium 20 is small, it can be suppressed that the working medium 20 is less likely to evaporate in the evaporation section. The protrusion 34f may be provided only on the periphery of the through hole 33 located directly above the heat source HS.

The through hole 33 and the convex portion 34f can be produced, for example, by punching the metal or the like that constitutes the perforated body 32 by press working. In punching by press working, the shape of the convex portion, etc. can be adjusted by appropriately adjusting the punching depth, etc. Note that the punching depth means, for example, how far the punch is pushed in the punching direction when punching is performed.

The dimensions of the convex portion 34f are not particularly limited. For example, the height of the protrusion 34f may be larger than the diameter of the through hole 33, the height of the protrusion 34f may be smaller than the diameter of the through hole 33, and the height of the protrusion 34f may be It may be the same as the diameter of the through hole 33. In addition, in the convex part 34f shown in FIG. 16A, the height of the convex part 34f means the distance in the thickness direction Z between the 1st end part 35f and the 2nd end part 36f.

In the example shown in FIG. 16A, the bending height of the edge of the wick 30E (distance indicated by B in FIG. 16A) is greater than the height of the convex portion 34f. The bending height of the edge of the wick 30E (the distance indicated by B in FIG. 16A) may be smaller than the height of the protrusion 34f, or may be the same as the height of the protrusion 34f.

Note that when a protrusion 34f is provided at the peripheral edge of the through hole 33 in a direction approaching the first inner surface 11a, the thickness of the perforated body 32 is equal to the thickness of the perforated body 32 at the portion where the protrusion 34f is not provided. It means the thickness of the body 32.

In the wick 30E shown in FIG. 16A, a support 31 is formed in the recessed part by bending and recessing a part of the metal foil by pressing or the like. The wick 30E may be formed by simultaneously performing the press work for forming the support body 31 and the press work for forming the through hole 33 and the convex portion 34f.

In the wick 30E shown in FIG. 16A, the support 31 does not have to be recessed like the wick 30A shown in FIG. 7, the wick 30B shown in FIG. 8, and the wick 30C shown in FIG.

FIG. 17 is a partially enlarged cross-sectional view schematically showing a first modification of the convex portion shown in FIG. 16A.

The convex portion 34g shown in FIG. 17 has a first end 35g on the first inner surface 11a side and a second end 36g on the second inner surface 12a side. In the convex portion 34g, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the first end portion 35g is smaller than the cross-sectional area of the region surrounded by the inner wall of the second end portion 36g. When the cross-sectional area of the region surrounded by the inner wall of the first end 35g is smaller than the cross-sectional area of the region surrounded by the inner wall of the second end 36g when viewed from the thickness direction Z, the inner wall of the first end 35g surrounds the region. can improve the capillary force generated in the area where the Therefore, since the capillary force of the wick 30E can be improved, the maximum heat transport amount of the vapor chamber 1 can be improved.

In the convex portion 34g, the inner wall of the first end portion 35g may be located inside the inner wall of the second end portion 36g when viewed from the thickness direction Z.

The convex portion 34g has a tapered shape in a cross section along the thickness direction Z such that the distance between the outer walls of the convex portion 34g becomes narrower toward the first inner surface 11a.

The convex portion 34g has a shape that is convex toward the first inner surface 11a side (lower side in FIG. 17) in the cross section along the thickness direction Z. In other words, the convex portion 34g curves toward the first inner surface 11a side (downward in FIG. 17) with respect to the line segment connecting the first end portion 35g and the second end portion 36g in the cross section along the thickness direction Z. It is the shape.

FIG. 18 is a partially enlarged sectional view schematically showing a second modification of the convex portion shown in FIG. 16A.

The convex portion 34h shown in FIG. 18 has a first end 35h on the first inner surface 11a side and a second end 36h on the second inner surface 12a side. The convex portion 34h has a tapered shape in a cross section along the thickness direction Z such that the distance between the outer walls of the convex portion 34h becomes narrower toward the first inner surface 11a. The convex portion 34h has a convex shape toward the second inner surface 12a side (upper side in FIG. 18) in a cross section along the thickness direction Z. In other words, the convex portion 34h has a shape that curves toward the second inner surface 12a side (upper side in FIG. 18) with respect to the line segment connecting the first end portion 35h and the second end portion 36h in the cross section along the thickness direction Z. It is.

FIG. 19 is a partially enlarged cross-sectional view schematically showing a third modification of the convex portion shown in FIG. 16A.

The convex portion 34i shown in FIG. 19 has a first end 35i on the first inner surface 11a side and a second end 36i on the second inner surface 12a side. In the convex portion 34i, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the first end portion 35i is smaller than the cross-sectional area of the region surrounded by the inner wall of the second end portion 36i. The convex portion 34i includes a lid portion 37 that narrows the opening of the convex portion 34i at the first end 35i. In the convex portion 34i, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the first end 35i is narrower than that of the convex portion 34h in which the lid portion 37 does not exist at the first end 35i. There is.

The lid portion 37 that narrows the opening of the convex portion 34i may be formed by, for example, pressing the first end portion 35i. The size and shape of the lid 37 that narrows the opening of the convex portion 34i are not particularly limited, as long as the opening on the first end 35i side of the convex portion 34i is narrowed. It is preferable that the lid portion 37 that narrows the opening of the convex portion 34i has a flat surface. The lid portion 37 that narrows the opening of the convex portion 34i is preferably a flat surface perpendicular to the thickness direction Z. The lid portion 37 that narrows the opening of the convex portion 34i may have a curved shape in part or in its entirety. The lid portion 37 that narrows the opening of the convex portion 34i may have an uneven surface. The thickness of the lid portion 37 that narrows the opening of the convex portion 34i may be the same as or different from the thickness of the convex portion 34i.

FIG. 20 is a partially enlarged sectional view schematically showing a fourth modification of the convex portion shown in FIG. 16A.

The convex portion 34j shown in FIG. 20 has a first end 35j on the first inner surface 11a side and a second end 36j on the second inner surface 12a side. In the convex portion 34j, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the first end portion 35j is larger than the cross-sectional area of the region surrounded by the inner wall of the second end portion 36j. When the cross-sectional area of the region surrounded by the inner wall of the first end 35j is larger than the cross-sectional area of the region surrounded by the inner wall of the second end 36j when viewed from the thickness direction Z, the working medium 20 flows into the through hole 33. The amount of suction can be increased. When the amount of working medium 20 sucked into the through hole 33 is large, when the working medium 20 in the vapor chamber 1 decreases, the amount of working medium 20 until no working medium 20 is sucked up into the through hole 33 will increase. The permissible value of fluctuation becomes larger. Therefore, the robustness against the amount of working medium 20 in vapor chamber 1 is improved.

In the convex portion 34j, the inner wall of the first end 35j may be located outside the inner wall of the second end 36j when viewed from the thickness direction Z.

FIG. 21 is a partially enlarged sectional view schematically showing a fifth modification of the convex portion shown in FIG. 16A.

The convex portion 34k shown in FIG. 21 has a first end 35k on the first inner surface 11a side and a second end 36k on the second inner surface 12a side. In the convex portion 34k, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the first end portion 35k is larger than the cross-sectional area of the region surrounded by the inner wall of the second end portion 36k. The convex portion 34k includes a lid portion 37 that narrows the opening of the convex portion 34k at the first end 35k. In the convex portion 34k, when viewed from the thickness direction Z, the cross-sectional area of the region surrounded by the inner wall of the first end portion 35k is narrower than that of the convex portion 34j in which the lid portion 37 does not exist at the first end portion 35k. There is.

The lid portion 37 that narrows the opening of the convex portion 34k may be formed by, for example, performing press working on the first end portion 35k. The size and shape of the lid portion 37 that narrows the opening of the convex portion 34k are not particularly limited, as long as the opening on the first end 35k side of the convex portion 34k is narrowed. It is preferable that the lid portion 37 that narrows the opening of the convex portion 34k has a flat surface. The lid portion 37 that narrows the opening of the convex portion 34k is preferably a flat surface perpendicular to the thickness direction Z. The lid portion 37 that narrows the opening of the convex portion 34k may have a curved surface in part or in its entirety. The lid portion 37 that narrows the opening of the convex portion 34k may have an uneven surface. The thickness of the lid portion 37 that narrows the opening of the convex portion 34k may be the same as or different from the thickness of the convex portion 34k.

FIG. 22 is a plan view schematically showing a sixth modification of the wick. Note that FIG. 22 is a plan view of the wick viewed from the support body side.

In the wick 30F shown in FIG. 22, the support body 31 includes a plurality of rail-shaped members. By holding the liquid-phase working medium 20 between the rail-like members, the heat transport performance of the vapor chamber 1 can be improved. Here, "rail shape" means a shape in which the ratio of the length of the long side of the bottom surface is 5 times or more to the length of the short side of the bottom surface.

The cross-sectional shape perpendicular to the extending direction of the rail-like member is not particularly limited, and examples thereof include polygons such as quadrangles, semicircles, semiellipses, and combinations thereof.

It is sufficient that the rail-shaped member is relatively higher in height than its surroundings. Therefore, in addition to the portion protruding from the first inner surface 11a, the rail-like member also includes a portion having a relatively high height due to the groove formed in the first inner surface 11a.

Furthermore, the wick 30F is not limited to the shape shown in FIG. 22, and may be used by being partially disposed instead of being disposed throughout the interior space. For example, a rail-shaped support 31 may be configured in the internal space along the outer periphery, and a perforated body 32 shaped along the outer periphery may be arranged thereon.

FIG. 23 is a plan view schematically showing the arrangement of the wicks when the heat diffusion device shown in FIG. 1 is viewed from the thickness direction.

In the vapor chamber 1 shown in FIG. 23, the wick 30 is arranged throughout the interior space of the casing 10 when viewed from the thickness direction Z.

In the vapor chamber 1 shown in FIG. 23, the evaporation portion EP (evaporation portion) overlaps the inner edge of the housing 10 when viewed from the thickness direction Z. In the vapor chamber 1 shown in FIG. 23, the evaporation part EP overlaps the wick 30 when viewed from the thickness direction Z.

In FIG. 23, the edge of the wick 30 and the inner edge of the casing 10 are not in contact. The edge of the wick 30 and the inner edge of the housing 10 may be in contact with each other.

FIG. 24 is a plan view schematically showing the arrangement of the wicks when the first modification of the heat diffusion device of the present invention is viewed from the thickness direction.

In the vapor chamber (thermal diffusion device) 1A shown in FIG. 24, the wick 30 is disposed over the entire internal space of the casing 10 when viewed from the thickness direction Z, and the internal space is It has a region where the wick 30 is arranged and a region where the wick 30 is not arranged, and the region where the wick 30 is not arranged extends linearly when viewed from the thickness direction Z. .

In the vapor chamber 1A, the region where the wick 30 is not arranged may extend linearly or curvedly when viewed from the thickness direction Z.

In the vapor chamber 1A, among the edges of the wick 30, the edge on the inner edge side of the housing 10 is bent toward the first inner surface 11a side. Among the edges of the wick 30, the edge on the side of the area where the wick 30 is not arranged may be curved so as to approach the first inner surface 11a side, and may approach the edge toward the first inner surface 11a side. It doesn't have to be bent like this.

In FIG. 24, the edge of the wick 30 and the inner edge of the casing 10 are not in contact. The edge of the wick 30 and the inner edge of the housing 10 may be in contact with each other.

In the vapor chamber 1A shown in FIG. 24, the evaporation part EP overlaps the inner edge of the casing 10 when viewed from the thickness direction Z. In the vapor chamber 1A shown in FIG. 24, the area where the wick 30 is not arranged may extend to the evaporation part EP when viewed from the thickness direction Z, or may not extend to the evaporation part EP.

FIG. 25 is a plan view schematically showing the arrangement of the wick when the second modification of the heat diffusion device of the present invention is viewed from the thickness direction.

In the vapor chamber (thermal diffusion device) 1B shown in FIG. 25, the wick 30 is arranged along the outer periphery of the internal space of the casing 10 when viewed from the thickness direction Z.

In the vapor chamber 1B, among the edges of the wick 30, the edge on the inner edge side of the housing 10 is bent toward the first inner surface 11a side. Among the edges of the wick 30, the edge on the side where the wick 30 is hollow may be bent so as to approach the first inner surface 11a side, and may be bent toward the first inner surface 11a side. It doesn't have to be bent like that.

In the vapor chamber 1B shown in FIG. 25, the evaporation part EP overlaps the inner edge of the casing 10 when viewed from the thickness direction Z. In the vapor chamber 1B shown in FIG. 25, the evaporation part EP overlaps the wick 30 when viewed from the thickness direction Z.

In FIG. 25, the edge of the wick 30 and the inner edge of the casing 10 are not in contact. The edge of the wick 30 and the inner edge of the housing 10 may be in contact with each other.

FIG. 26 is a cross-sectional view schematically showing a third modification of the heat diffusion device.

In the vapor chamber (thermal diffusion device) 1C shown in FIG. 26, the support body 31 is configured integrally with the first sheet 11 of the casing 10. In the vapor chamber 1C, the first sheet 11 and the support body 31 can be produced by, for example, an etching technique, a printing technique using multilayer coating, or another multilayer technique. In the vapor chamber 1C, the perforated body 32 may be made of the same material as the support body 31 and the first sheet 11 of the housing 10, or may be made of a different material. The perforated body 32 may be configured integrally with the support body 31 and the first sheet 11 of the housing 10.

FIG. 27 is a cross-sectional view schematically showing a fourth modification of the heat diffusion device.

In the vapor chamber (thermal diffusion device) 1D shown in FIG. 27, by bending and recessing a part of the first inner surface 11a of the casing 10 by, for example, pressing, a support body 31 is formed in the recessed part. There is.

The heat diffusion device of the present invention is not limited to the above embodiments, and various applications and modifications can be made within the scope of the present invention regarding the configuration, manufacturing conditions, etc. of the heat diffusion device.

In the heat diffusion device of the present invention, the casing may have one evaporation section or a plurality of evaporation sections. That is, one heat source or a plurality of heat sources may be arranged on the outer surface of the casing. The number of evaporation sections and heat sources is not particularly limited.

In the heat diffusion device of the present invention, when the casing is composed of a first sheet and a second sheet, the first sheet and the second sheet may overlap so that their edges coincide, or may be shifted and overlap.

In the heat diffusion device of the present invention, when the casing is composed of a first sheet and a second sheet, the material constituting the first sheet and the material constituting the second sheet may be different. For example, by using a material with high strength for the first sheet, stress applied to the housing can be dispersed. Moreover, by using different materials for both sheets, one function can be obtained with one sheet, and another function can be obtained with the other sheet. The above-mentioned functions are not particularly limited, but include, for example, a heat conduction function, an electromagnetic wave shielding function, and the like.

The heat diffusion device of the present invention can be installed in electronic equipment for the purpose of heat radiation. Therefore, electronic equipment including the heat diffusion device of the present invention is also one of the present inventions. Examples of the electronic device of the present invention include a smartphone, a tablet terminal, a notebook computer, a game device, a wearable device, and the like. As described above, the heat diffusion device of the present invention operates independently without requiring external power, and can diffuse heat two-dimensionally at high speed by utilizing the latent heat of vaporization and latent heat of condensation of the working medium. Therefore, an electronic device including the heat diffusion device of the present invention can effectively dissipate heat in a limited space inside the electronic device.

The following contents are disclosed in this specification.

<1>
a casing having a first inner surface and a second inner surface facing each other in the thickness direction;
A working medium sealed in the internal space of the casing;
a wick disposed in the internal space of the casing;
The wick includes a support in contact with the first inner surface and a perforated body in contact with the support,
In the heat diffusion device, an edge of the wick is bent toward the first inner surface.

<2>
The heat diffusion device according to <1>, wherein in a cross section along the thickness direction, a gap exists in a direction perpendicular to the thickness direction between the edge of the wick and the inner edge of the casing. .

<3>
The casing is composed of a first sheet and a second sheet that are joined at their outer edges and that face each other in the thickness direction,
The heat diffusion device according to <1> or <2>, wherein the joint between the first sheet and the second sheet is located at a different position from the edge of the wick in the thickness direction.

<4>
further comprising a post disposed in the internal space so as to be in contact with the second inner surface of the casing,
The heat diffusion device according to any one of <1> to <3>, wherein the height of the support column is greater than the height of the support body.

<5>
The heat diffusion device according to <4>, wherein the equivalent circle diameter of the cross section perpendicular to the height direction of the support is larger than the equivalent circle diameter of the cross section perpendicular to the height direction of the support.

<6>
The heat diffusion device according to <4> or <5>, wherein the distance between the centers of the support columns adjacent to each other is larger than the distance between the centers of the support bodies adjacent to each other.

<7>
The heat diffusion device according to any one of <1> to <6>, wherein the porous body is made of the same material as the support.

<8>
The heat diffusion device according to <7>, wherein the porous body and the support body are composed of porous bodies.

<9>
The heat diffusion device according to any one of <1> to <6>, wherein the porous body is made of a different material from the support.

<10>
The heat diffusion device according to <9>, wherein the porous body is composed of a porous body.

<11>
The heat diffusion device according to any one of <1> to <10>, wherein the thickness of the support is the same as the thickness of the porous body or smaller than the thickness of the porous body.

<12>
The porous body has a through hole penetrating in the thickness direction,
The heat diffusion device according to any one of <1> to <11>, wherein a convex portion is provided on a peripheral edge of the through hole in a direction approaching the second inner surface.

<13>
The convex portion has a first end on the first inner surface side and a second end on the second inner surface side,
The heat diffusion device according to <12>, wherein the cross-sectional area of the region surrounded by the inner wall of the second end is smaller than the cross-sectional area of the region surrounded by the inner wall of the first end, when viewed from the thickness direction.

<14>
The porous body has a through hole penetrating in the thickness direction,
The heat diffusion device according to any one of <1> to <11>, wherein a convex portion is provided on a peripheral edge of the through hole in a direction proximate to the first inner surface.

<15>
The convex portion has a first end on the first inner surface side and a second end on the second inner surface side,
The heat diffusion device according to <14>, wherein the cross-sectional area of the region surrounded by the inner wall of the first end is smaller than the cross-sectional area of the region surrounded by the inner wall of the second end, when viewed from the thickness direction.

<16>
The heat diffusion device according to any one of <1> to <15>, wherein the wick is disposed throughout the internal space of the housing when viewed from the thickness direction.

<17>
When viewed from the thickness direction, the wick is arranged throughout the internal space of the housing,
The internal space has a region where the wick is arranged and a region where the wick is not arranged when viewed from the thickness direction,
The heat diffusion device according to any one of <1> to <15>, wherein the region where the wick is not arranged extends linearly when viewed from the thickness direction.

<18>
The heat diffusion device according to any one of <1> to <15>, wherein the wick is arranged along the outer periphery of the internal space of the housing when viewed from the thickness direction.

<19>
An electronic device comprising the heat diffusion device according to any one of <1> to <18>.

The heat diffusion device of the present invention can be used for a wide range of applications in the field of mobile information terminals and the like. For example, it can be used to lower the temperature of a heat source such as a CPU and extend the usage time of electronic devices, and can be used for smartphones, tablet terminals, notebook computers, etc.

1, 1A, 1B, 1C, 1D Vapor chamber (thermal diffusion device)
10 Housing 11 First sheet 11a First inner surface 12 Second sheet 12a Second inner surface 13 Joint portion 20

Working medium

30, 30A, 30B, 30C, 30D, 30E, 30F Wick 31 Support body 32 Porous body 33 Through

hole

34 , 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h, 34i, 34j,

34k Convex portion

35, 35a, 35b, 35c, 35d, 35e, 35f, 35g, 35h, 35i, 35j, 35k First end

Parts

36, 36a, 36b, 36c, 36d, 36e, 36f, 36g, 36h, 36i, 36j, 36k Second end part 37 Lid part 40 Pillar HS Heat source EP Evaporation part P ₃₁ Distance between centers of support P ₃₃ Through hole Distance between centers T ₃₁ Height of support T ₃₂ Thickness of porous body W ₃₁ Width of support X Width direction Y Length direction Z Thickness direction A Distance between the far end of the wick and the inner edge of the casing B Bending height of wick edge C Bending width of wick edge φ Diameter of ₃₃ through hole

Claims

a casing having a first inner surface and a second inner surface facing each other in the thickness direction;
a working medium sealed in the internal space of the housing;
a wick disposed in the internal space of the housing,
The wick includes a support in contact with the first inner surface and a perforated body in contact with the support,
The edge of the wick is curved toward the first inner surface.
The heat diffusion device according to claim 1, wherein in a cross section along the thickness direction, a gap exists between an edge of the wick and an inner edge of the casing in a direction perpendicular to the thickness direction. .
The casing is composed of a first sheet and a second sheet that are joined at their outer edges and that face each other in the thickness direction,
The heat diffusion device according to claim 1 or 2, wherein a joint between the first sheet and the second sheet is located at a different position from an edge of the wick in the thickness direction.
further comprising a strut disposed in the internal space so as to be in contact with the second inner surface of the casing,
The heat spreading device according to any one of claims 1 to 3, wherein the height of the strut is greater than the height of the support.
The heat diffusion device according to claim 4, wherein the equivalent circle diameter of a cross section perpendicular to the height direction of the support is larger than the equivalent circle diameter of a cross section perpendicular to the height direction of the support.
The heat diffusion device according to claim 4 or 5, wherein the center-to-center distance between the mutually adjacent support columns is larger than the center-to-center distance between the mutually adjacent supports.
The heat diffusion device according to any one of claims 1 to 6, wherein the porous body is made of the same material as the support body.
The heat diffusion device according to claim 7, wherein the porous body and the support body are composed of a porous body.
The heat diffusion device according to any one of claims 1 to 6, wherein the porous body is made of a different material from the support body.
The heat diffusion device according to claim 9, wherein the porous body is composed of a porous body.
The heat diffusion device according to any one of claims 1 to 10, wherein the thickness of the support is the same as the thickness of the porous body or smaller than the thickness of the porous body.
The porous body has a through hole penetrating in the thickness direction,
The heat diffusion device according to any one of claims 1 to 11, wherein a convex portion is provided on a peripheral edge of the through hole in a direction approaching the second inner surface.
The convex portion has a first end on the first inner surface side and a second end on the second inner surface side,
The heat diffusion device according to claim 12, wherein a cross-sectional area of a region surrounded by an inner wall of the second end is smaller than a cross-sectional area of a region surrounded by an inner wall of the first end when viewed from the thickness direction.
The porous body has a through hole penetrating in the thickness direction,
The heat diffusion device according to any one of claims 1 to 11, wherein a convex portion is provided on a peripheral edge of the through hole in a direction proximate to the first inner surface.
The convex portion has a first end on the first inner surface side and a second end on the second inner surface side,
The heat diffusion device according to claim 14, wherein a cross-sectional area of a region surrounded by an inner wall of the first end is smaller than a cross-sectional area of a region surrounded by an inner wall of the second end when viewed from the thickness direction.
The heat diffusion device according to any one of claims 1 to 15, wherein the wick is arranged throughout the internal space of the housing when viewed from the thickness direction.
When viewed from the thickness direction, the wick is arranged throughout the internal space of the housing,
The internal space has a region where the wick is arranged and a region where the wick is not arranged when viewed from the thickness direction,
The heat diffusion device according to any one of claims 1 to 15, wherein the region where the wick is not arranged extends linearly when viewed from the thickness direction.
The heat diffusion device according to any one of claims 1 to 15, wherein the wick is arranged along the outer periphery of the internal space of the housing when viewed from the thickness direction.
An electronic device comprising the heat diffusion device according to any one of claims 1 to 18.