WO2024018846A1 - Heat diffusing device, and electronic apparatus - Google Patents

Abstract

A vapor chamber 1, which is one embodiment of a heat diffusing device, comprises a housing 10 which has a first inner surface 11a and a second inner surface 12a that face one another in a thickness direction Z and which is provided with an internal space, an operating medium 20 sealed in the internal space of the housing 10, a sheet-like wick 30 disposed in the internal space of the housing 10, a sheet member 35 which is disposed in the internal space of the housing 10 and which is a member that is the same as or different from the wick 30, a plurality of first supporting bodies 40 integrated with the wick 30, and a plurality of second supporting bodies 50 integrated with the sheet member 35; and the wick 30 is separated from the first inner surface 11a by means of the first supporting bodies 40 and is separated from the second inner surface 12a by means of the second supporting bodies 50.

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 of electronic components in the evaporator, 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 disclosed in which a 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

FIG. 1 of Patent Document 1 shows, as an embodiment of the vapor chamber, a structure in which a wick is sandwiched between a convex part of a microchannel formed on a lower housing sheet and a column formed on an upper housing sheet. It is shown. Further, Patent Document 1 describes that the unevenness of the microchannels is formed by etching the lower casing sheet, and that the pillars are formed by etching the upper casing sheet.

In the vapor chamber described in Patent Document 1, when attempting to arrange microchannels and struts having fine and complicated structures in the internal space of the casing, the design of the lower casing sheet and the upper casing sheet becomes complicated. , the manufacturing cost of the housing may increase.

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 simplify the design of the casing. Furthermore, an object of the present invention is to provide an electronic device including the above 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 and provided with an internal space, and a working medium sealed in the internal space of the casing. a sheet-like wick disposed in the internal space of the casing; a sheet member disposed in the internal space of the casing that is the same as or different from the wick; and a sheet member integrated with the wick. a plurality of first supports integrated with the sheet member, and a plurality of second supports integrated with the sheet member, the wick being separated from the first inner surface via the first support. At the same time, it is separated from the second inner surface via the second support.

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 simplify the design of the casing. 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 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of the heat diffusion device according to the first embodiment of the present invention. FIG. 3 is a plan view schematically showing an example of a wick, a first support, and a second support that constitute the heat diffusion device according to the first embodiment of the present invention. FIG. 4 is an example of a cross-sectional view of the wick shown in FIG. 3 taken along line AA. FIG. 5 is an example of a cross-sectional view of the wick and the first support shown in FIG. 3 taken along line BB. FIG. 6 is an example of a cross-sectional view of the wick and the second support shown in FIG. 3 taken along line CC. FIG. 7 is another example of a cross-sectional view of the wick shown in FIG. 3 taken along line AA. FIG. 8 is a cross-sectional view schematically showing an example of a heat diffusion device according to a second embodiment of the present invention. FIG. 9 is a sectional view showing a first modification of the wick, sheet member, first support, and second support that constitute the heat diffusion device according to the second embodiment of the present invention. FIG. 10 is a sectional view showing a second modification of the wick, sheet member, first support, and second support that constitute the heat diffusion device according to the second embodiment of the present invention. FIG. 11 is a sectional view showing a third modification of the wick, sheet member, first support, and second support that constitute the heat diffusion device according to the second embodiment of the present invention.

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.

The heat diffusion device of the present invention is characterized in that the first support is integrated with the wick, and the second support is integrated with the sheet member. Unlike the structure described in Patent Document 1, it is not necessary to form the first support body and the second support body on the inner surface of the housing by processing such as etching, so the design of the housing can be simplified. becomes. For example, as in Patent Document 1, when a housing is constructed from an upper housing sheet and a lower housing sheet that face each other and whose outer edges are joined, the inner surfaces of the upper and lower housing sheets have a fine and complicated structure. By eliminating the support, the upper and lower housing sheets can have a simple bathtub shape. Therefore, the manufacturing cost of the housing can be reduced.

The method of forming the first support or the second support is not particularly limited, but for example, by bending and recessing a part of the metal foil constituting the wick or sheet member by processing such as press processing, the recessed portion may be formed. The first support or the second support can be formed on the substrate. In this case, compared to the case where the first support body and the second support body are formed on the inner surface of the casing by processing such as etching, the metal volume of the support body part can be reduced, so the weight of the heat diffusion device can be reduced. becomes possible.

In the heat diffusion device of the present invention, "the first support is integrated with the wick" means that there is no interface between the first support and the wick. 1 This means that the boundary between the support and the wick cannot be determined. For example, in a structure in which a copper pillar as a first support and a copper mesh as a wick are fixed by diffusion bonding or spot welding, it is not possible to bond the entire surface between the first support and the wick. Due to this difficulty, a gap is created between the first support and the wick. In such a structure, since a boundary can be discerned between the first support and the wick, it can be said that the first support and the wick are not integrally constituted.

Similarly, in the heat diffusion device of the present invention, "the second support is integrated with the sheet member" means that there is no interface between the second support and the sheet member; Specifically, this means that the boundary between the second support and the sheet member cannot be determined.

In the heat diffusion device of the present invention, the sheet member may be the same member as the wick, or may be a different member from the wick. When the sheet member is the same member as the wick, the first support body is integrated with the wick, and the second support body is also integrated with the wick.

It goes without saying that each of the embodiments shown below is an example, and that parts of the configurations shown in different embodiments can be partially replaced or combined. In the second embodiment and subsequent embodiments, descriptions of matters common to the first embodiment will be omitted, and only different points will be described. In particular, similar effects due to similar configurations will not be mentioned for each embodiment.

In the following description, unless the embodiments are particularly distinguished, they will simply be referred to as "the heat diffusion device of the present invention."

An embodiment of the heat diffusion device of the present invention will be described below using a vapor chamber as an example. 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, aspect ratio, etc. may differ from the actual product. In the figures, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are given the same reference numerals and redundant explanations will be omitted.

In this specification, terms that indicate relationships between elements (e.g., "perpendicular," "parallel," "orthogonal," etc.) and terms that indicate the shape of elements are not expressions that express only strict meanings, but substantially This expression means that it includes an equivalent range, for example, a difference of several percent.

[First embodiment]
In the heat diffusion device according to the first embodiment of the present invention, the sheet member is the same member as the wick. That is, the wick also serves as a sheet member. Therefore, there is no sheet member separate from the wick.

FIG. 1 is a perspective view schematically showing an example of a heat diffusion device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of the heat diffusion device according to the first embodiment 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 housing 10 is provided with an internal space. The vapor chamber 1 further includes a working medium 20 sealed in the internal space of the housing 10 , a sheet-like wick 30 disposed in the internal space of the housing 10 , and a plurality of vapor chambers integrated with the wick 30 . 1 support body 40 and a plurality of second support bodies 50 that are integrated with the wick 30.

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 face each other and whose outer edges are joined.

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 characteristics suitable for use as a heat diffusion device such as a vapor chamber, e.g. It is not particularly limited as long as it has thermal conductivity, strength, flexibility, flexibility, 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 first sheet 11 and the second sheet 12 are joined to each other at their outer edges. 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.

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 use of the heat diffusion device such as the vapor chamber, the shape of the part where the heat diffusion device such as 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, alcohol, 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 material constituting the wick 30 is not particularly limited, but is preferably a metal, such as copper, nickel, aluminum, magnesium, titanium, iron, or an alloy containing these as main components, and copper is particularly preferred. . The material forming the wick 30 may be the same as or different from the material forming the housing 10.

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.

The thickness of the wick 30 is not particularly limited, but is, for example, 5 μm or more and 50 μm or less.

The wick 30 may have a plurality of through holes 31 penetrating in the thickness direction Z.

The wick 30 is separated from the first inner surface 11a via the first support 40 and is separated from the second inner surface 12a via the second support 50.

The first support body 40 may or may not be in contact with the first inner surface 11a. When the first support body 40 is in contact with the first inner surface 11a, the first support body 40 may or may not be joined to the first inner surface 11a.

The second support body 50 may or may not be in contact with the second inner surface 12a. When the second support body 50 is in contact with the second inner surface 12a, the second support body 50 may or may not be joined to the second inner surface 12a.

The first support body 40 includes, for example, a plurality of columnar members. 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.

Alternatively, the first support body 40 may include a plurality of rail-shaped members. 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.

A liquid phase working medium 20 is held between the first supports 40 . Thereby, the heat transport performance of the vapor chamber 1 can be improved.

When the first support body 40 includes a plurality of columnar members, the shape of the first support body 40 is not particularly limited, but may have a shape such as a columnar shape, an elliptical columnar shape, a prismatic shape, a truncated cone shape, or a truncated pyramid shape. Can be mentioned.

When the first support body 40 includes a plurality of rail-like members, the cross-sectional shape perpendicular to the extending direction of the first support body 40 is not particularly limited; , a shape that is a combination of these, etc.

As shown in FIG. 2, the first support body 40 may have a tapered shape whose width becomes narrower from the wick 30 toward the first inner surface 11a. Thereby, the flow path between the first supports 40 can be widened on the housing 10 side.

The height of the first support body 40 may be the same or different in one vapor chamber.

The second support body 50 includes, for example, a plurality of columnar members. Alternatively, the second support body 50 may include a plurality of rail-like members.

The housing 10 and the wick 30 are supported by the second support body 50.

When the second support body 50 includes a plurality of columnar members, the shape of the second support body 50 is not particularly limited; Can be mentioned.

When the second support body 50 includes a plurality of rail-like members, the cross-sectional shape perpendicular to the extending direction of the second support body 50 is not particularly limited; , a shape that is a combination of these, etc.

As shown in FIG. 2, the second support body 50 may have a tapered shape whose width becomes narrower from the wick 30 toward the second inner surface 12a. Thereby, the flow path between the second supports 50 can be widened on the housing 10 side.

The height of the second support body 50 may be the same or different in one vapor chamber.

The method for forming the first support 40 and the second support 50 is not particularly limited, but for example, by bending and recessing a part of the metal foil constituting the wick 30 by processing such as press working, a recessed portion may be formed. The first support 40 and the second support 50 can be formed. The process of forming the first support body 40 and the process of forming the second support body 50 may be performed at once. Since a vapor space is formed in the recessed portion of the first support 40, thermal conductivity is improved. Note that when press working is performed on the metal foil, depending on the condition of the press working, a through hole may be formed in a recessed portion when a part of the metal foil is bent.

It is preferable that the thickness of the metal foil before being processed such as press working is constant. However, the metal foil may become thinner in bent areas. Therefore, as in the example shown in FIG. 2, it is preferable that the thickness of the first support body 40 is the same as the thickness of the wick 30 or smaller than the thickness of the wick 30. Further, it is preferable that the thickness of the second support body 50 is the same as the thickness of the wick 30 or smaller than the thickness of the wick 30. The thickness of the first support body 40 is the same as the thickness of the wick 30, or is smaller than the thickness of the wick 30, and the thickness of the second support body 50 is the same as the thickness of the wick 30, or , is more preferably smaller than the thickness of the wick 30.

FIG. 3 is a plan view schematically showing an example of a wick, a first support, and a second support that constitute the heat diffusion device according to the first embodiment of the present invention. FIG. 4 is an example of a cross-sectional view of the wick shown in FIG. 3 taken along line AA. FIG. 5 is an example of a cross-sectional view of the wick and the first support shown in FIG. 3 taken along line BB. FIG. 6 is an example of a cross-sectional view of the wick and the second support shown in FIG. 3 taken along line CC.

In the example shown in FIGS. 3 and 4, the wick 30 has a plurality of through holes 31 that penetrate in the thickness direction Z.

The working medium 20 can move within the through hole 31 due to capillary action. It is preferable that the through hole 31 be provided in a portion where the first support body 40 is not present when viewed from the thickness direction Z. Although the shape of the through hole 31 is not particularly limited, it is preferable that the cross section in a plane perpendicular to the thickness direction Z is circular or elliptical.

When the wick 30 has a plurality of through holes 31 penetrating in the thickness direction Z, the arrangement of the through holes 31 is not particularly limited, but it is preferable that the through holes 31 are arranged uniformly in a predetermined area, more preferably evenly throughout, for example. 31 are arranged so that the center-to-center distance (pitch) is constant.

The distance between the centers of the through holes 31 is, for example, 3 μm or more and 150 μm or less. The diameter of the through hole 31 is, for example, 100 μm or less. In addition, when the diameter of the through-hole 31 differs in the thickness direction Z, the diameter of the smallest part is defined as the diameter of the through-hole 31.

The through-hole 31 can be formed, for example, by punching the metal foil that constitutes the wick 30 by press working. The press work to form the first support body 40 and the press work to form the through hole 31 may be performed at once, and the press work to form the second support body 50 and the press work to form the through hole 31 may be performed all at once.

In the example shown in FIGS. 3 and 5, the first support body 40 includes a plurality of columnar members. Although the first support body 40 is not provided with the through hole 31 in FIGS. 3 and 5, the through hole 31 may be provided, for example, at the bottom (concave portion) of the first support body 40.

The arrangement of the first supports 40 is not particularly limited, but is preferably arranged evenly in a predetermined area, more preferably evenly over the entire area, for example, so that the center-to-center distance (pitch) of the first supports 40 is constant. be done.

The distance between the centers of adjacent first supports 40 is, for example, 60 μm or more and 800 μm or less. The equivalent circle diameter of the cross section perpendicular to the height direction of the end of the first support 40 on the wick 30 side is, for example, 20 μm or more and 500 μm or less. The height of the first support body 40 is, for example, 10 μm or more and 100 μm or less.

In the example shown in FIGS. 3 and 6, the second support body 50 includes a plurality of columnar members. Although the second support body 50 is not provided with the through hole 31 in FIGS. 3 and 6, the through hole 31 may be provided, for example, at the bottom (concave portion) of the second support body 50.

The arrangement of the second supports 50 is not particularly limited, but is preferably arranged evenly in a predetermined area, more preferably evenly over the entire area, for example, so that the center-to-center distance (pitch) of the second supports 50 is constant. be done. By arranging the second supports 50 evenly, uniform strength can be ensured over the entire heat diffusion device such as a vapor chamber.

The distance between the centers of adjacent second supports 50 is, for example, 100 μm or more and 5000 μm or less. The equivalent circle diameter of the cross section perpendicular to the height direction of the end of the second support 50 on the wick 30 side 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 circle diameter of the second support body 50, deformation of the housing 10 can be further suppressed. On the other hand, by reducing the equivalent circle diameter of the second support body 50, it is possible to secure a wider space for the vapor of the working medium 20 to move. The height of the second support body 50 is, for example, 50 μm or more and 1000 μm or less.

The height of the first support 40 is preferably smaller than the height of the second support 50.

The distance between the centers of adjacent first supports 40 is preferably smaller than the distance between the centers of adjacent second supports 50.

The equivalent circle diameter of the cross section perpendicular to the height direction of the end of the first support 40 on the wick 30 side is the equivalent circle diameter of the cross section perpendicular to the height direction of the end of the second support 50 on the wick 30 side. Preferably smaller.

When the wick 30 has a plurality of through holes 31 penetrating in the thickness direction Z, as shown in FIG. A convex portion 32 may be provided on the upper side).

If a convex portion 32 is provided at the periphery of the through hole 31 in a direction approaching the second inner surface 12a, the vapor of the working medium 20 flowing in the space between the wick 30 and the second inner surface 12a will be absorbed by the convex portion 32. It flows around the outer periphery. Therefore, the flow of the vapor of the working medium 20 can be prevented from coming into direct contact with the liquid level of the working medium 20 in the through hole 31 . Therefore, the influence of the flow of steam in the direction opposite to the capillary force of the wick 30, so-called counterflow, can be reduced. As a result, the maximum heat transport amount is improved.

FIG. 7 is another example of a cross-sectional view of the wick shown in FIG. 3 taken along line AA.

When the wick 30 has a plurality of through holes 31 penetrating in the thickness direction Z, as shown in FIG. A convex portion 33 may be provided on the lower side).

If a convex portion 33 is provided at the periphery of the through hole 31 in a direction approaching the first inner surface 11a, the working medium 20 in contact with the surface surrounded by the inner wall of the convex portion 33 is sucked up into the through hole 31 by capillary force. It will be done. Therefore, when the liquid amount of the working medium 20 is small, specifically, even when the liquid level of the working medium 20 is located closer to the first inner surface 11a than the wick 30, the amount of liquid in the through hole 31 is small. The working medium 20 can be sucked up. As a result, even when the amount of working medium 20 is small, deterioration in heat soaking performance and heat transport performance is suppressed.

In this way, if the convex portion 33 is provided on the periphery of the through hole 31 in the direction approaching the first inner surface 11a, even if the amount of the working medium 20 is small, the thermal uniformity performance and heat transport performance will deteriorate. For example, changes in the design value of the amount of working medium 20 injected in the manufacturing process, variations in the amount of injected working medium 20 in the manufacturing process, fluctuations in the amount of working medium 20 during use, etc. It has little effect on soaking performance or heat transport performance. In other words, if the convex portion 33 is provided on the periphery of the through hole 31 in a direction approaching the first inner surface 11a, it can be said that the robustness against the amount of the working medium 20 is improved.

Although the convex portion 32 or the convex portion 33 may be provided only on a part of the periphery of the through hole 31, it is preferably provided on the entire periphery of the through hole 31.

The convex portion 32 or the convex portion 33 can be formed, for example, by punching the metal foil that constitutes the wick 30 by press working. In that case, the convex portion 32 or the convex portion 33 may be formed at the same time as the through hole 31, or may be formed separately from the through hole 31. In punching by press working, the shape of the convex portion 32 or the convex portion 33 can be adjusted by appropriately adjusting the depth of punching and the like. 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 32 or the convex portion 33 are not particularly limited, and for example, the height of the convex portion 32 or the convex portion 33 may be larger than the diameter of the through hole 31, or may be smaller than the diameter of the through hole 31. , may be the same as the diameter of the through hole 31.

The shape of the convex portion 32 is not particularly limited, and for example, in the cross section along the thickness direction Z, the distance between the outer walls of the convex portion 32 increases in the direction approaching the second inner surface 12a (in the upward direction in FIG. 4). It may be a tapered shape that becomes narrower, or it may be an inverted tapered shape that the distance between the outer walls of the convex portion 32 becomes wider. In these cases, the convex portion 32 may have a shape that is convex toward the second inner surface 12a side (upper side in FIG. 4) in the cross section along the thickness direction Z, and may have a convex shape toward the first inner surface 11a side (lower side in FIG. 4). ) may have a convex shape. Further, the convex portion 32 may have a lid portion that narrows the opening of the convex portion 32 at the end on the second inner surface 12a side.

Similarly, the shape of the convex portion 33 is not particularly limited, and for example, in a cross section along the thickness direction Z, the shape between the outer walls of the convex portion 33 is It may be a tapered shape in which the distance between the convex portions 33 is narrow, or it may be a reverse tapered shape in which the distance between the outer walls of the convex portions 33 is widened. In these cases, the convex portion 33 may have a shape that is convex toward the second inner surface 12a side (upper side in FIG. 7) in the cross section along the thickness direction Z, and may have a convex shape toward the first inner surface 11a side (lower side in FIG. 7). ) may have a convex shape. Further, the convex portion 33 may have a lid portion that narrows the opening of the convex portion 33 at the end on the first inner surface 11a side.

When the wick 30 has a plurality of through holes 31 penetrating in the thickness direction Z, the protrusions 32 and the protrusions 33 may be provided at the periphery of the through hole 31 in a mixed manner. The portion 33 may not be provided.

[Second embodiment]
In the heat diffusion device according to the second embodiment of the present invention, the sheet member is a member different from the wick. Therefore, a sheet member exists separately from the wick.

FIG. 8 is a cross-sectional view schematically showing an example of a heat diffusion device according to the second embodiment of the present invention.

The vapor chamber (thermal diffusion device) 2 shown in FIG. 8 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 housing 10 is provided with an internal space. The vapor chamber 2 further includes a working medium 20 sealed in the internal space of the housing 10 , a sheet-like wick 30 disposed in the internal space of the housing 10 , and a sheet disposed in the internal space of the housing 10 . It includes a member 35, a plurality of first supports 40 integrated with the wick 30, and a plurality of second supports 50 integrated with the sheet member 35.

The vapor chamber 2 shown in FIG. 8 is the same as the vapor chamber 1 shown in FIG. 2 except that the sheet member 35 is a different member from the wick 30 and the second support body 50 is integrated with the sheet member 35. It has the following configuration.

The wick 30 may have a plurality of through holes 31 penetrating in the thickness direction Z.

The material constituting the sheet member 35 is not particularly limited, but is preferably a metal, such as copper, nickel, aluminum, magnesium, titanium, iron, or an alloy containing these as main components, and particularly preferably copper. be. The material constituting the sheet member 35 may be the same as the material constituting the housing 10, or may be different. Furthermore, the material forming the sheet member 35 may be the same as or different from the material forming the wick 30.

Although the size and shape of the sheet member 35 are not particularly limited, it is preferable, for example, that the sheet member 35 is arranged continuously in the internal space of the casing 10. The sheet member 35 may be disposed in the entire internal space of the casing 10 when viewed from the thickness direction Z, or the sheet member 35 may be disposed in a part of the internal space of the casing 10 when viewed from the thickness direction Z. may be placed. The size and shape of the sheet member 35 may be the same as or different from the size and shape of the wick 30.

The thickness of the sheet member 35 is not particularly limited, but is, for example, 5 μm or more and 50 μm or less. The thickness of the sheet member 35 may be the same as the thickness of the wick 30, may be greater than the thickness of the wick 30, or may be smaller than the thickness of the wick 30.

In the example shown in FIG. 8, the sheet member 35 is arranged between the second inner surface 12a and the second support body 50. It is preferable that the second support body 50 is in contact with the wick 30.

The sheet member 35 may or may not be in contact with the second inner surface 12a. When the sheet member 35 is in contact with the second inner surface 12a, the sheet member 35 may or may not be joined to the second inner surface 12a.

It is preferable that the sheet member 35 does not have a through hole 31 penetrating in the thickness direction Z.

The second support body 50 may have a tapered shape whose width becomes narrower from the second inner surface 12a toward the wick 30, as shown in FIG. Thereby, the flow path between the second supports 50 can be widened on the wick 30 side.

The method for forming the first support 40 and the second support 50 is not particularly limited, but for example, by bending and recessing a part of the metal foil constituting the wick 30 by processing such as press working, a recessed portion may be formed. By forming the first support body 40 in the recessed part and bending and recessing a part of the metal foil constituting the sheet member 35 by processing such as press working, the second support body 50 can be formed in the recessed part. can. Since a vapor space is formed in the recessed portion of the first support 40, thermal conductivity is improved. Note that when press working is performed on the metal foil, depending on the condition of the press working, a through hole may be formed in a recessed portion when a part of the metal foil is bent.

It is preferable that the thickness of the metal foil before being processed such as press working is constant. However, the metal foil may become thinner in bent areas. Therefore, as in the example shown in FIG. 8, it is preferable that the thickness of the first support body 40 is the same as the thickness of the wick 30 or smaller than the thickness of the wick 30. Further, it is preferable that the thickness of the second support body 50 is the same as the thickness of the sheet member 35 or smaller than the thickness of the sheet member 35. The thickness of the first support body 40 is the same as the thickness of the wick 30, or is smaller than the thickness of the wick 30, and the thickness of the second support body 50 is the same as the thickness of the sheet member 35, Alternatively, it is more preferable that the thickness is smaller than the thickness of the sheet member 35.

When the wick 30 has a plurality of through holes 31 penetrating in the thickness direction Z, the preferred arrangement of the through holes 31 is the same as in the first embodiment. Further, the distance between the centers of the through holes 31 and the preferable range of the diameter of the through holes 31 are also the same as in the first embodiment.

The preferred arrangement of the first support body 40 is the same as in the first embodiment. In addition, the distance between the centers of adjacent first supports 40 , the equivalent circle diameter of a cross section perpendicular to the height direction of the end of the first support 40 on the wick 30 side, and the height of the first support 40 The preferred range is also the same as in the first embodiment.

The preferred arrangement of the second support body 50 is the same as in the first embodiment. In addition, the distance between the centers of adjacent second supports 50, the equivalent circle diameter of the cross section perpendicular to the height direction of the end of the second support 50 on the wick 30 side, and the height of the second support 50 The preferred range is also the same as in the first embodiment.

The height of the first support 40 is preferably smaller than the height of the second support 50.

The distance between the centers of adjacent first supports 40 is preferably smaller than the distance between the centers of adjacent second supports 50.

The equivalent circle diameter of the cross section perpendicular to the height direction of the end of the first support 40 on the wick 30 side is the equivalent circle diameter of the cross section perpendicular to the height direction of the end of the second support 50 on the wick 30 side. Preferably smaller.

When the sheet member 35 is a member different from the wick 30, the wick 30 is configured so that the height, center-to-center distance, or equivalent circle diameter of the first support 40 and the second support 50 satisfy the above relationship. The metal foil is less likely to be torn when forming the through hole 31 in the metal foil.

FIG. 9 is a sectional view showing a first modification of the wick, sheet member, first support, and second support that constitute the heat diffusion device according to the second embodiment of the present invention.

In the example shown in FIG. 9, the wick 30A is similar to the wick 30, but the first support 40A is not recessed.

The materials constituting the wick 30A and the first support body 40A are not particularly limited, and examples thereof include resins, metals, ceramics, mixtures thereof, and laminates. The material constituting the wick 30A and the first support body 40A is preferably metal.

The wick 30A and the first support 40A can be produced by, for example, an etching technique, a printing technique using multilayer coating, or another multilayer technique.

FIG. 10 is a sectional view showing a second modification of the wick, sheet member, first support, and second support that constitute the heat diffusion device according to the second embodiment of the present invention.

In the example shown in FIG. 10, the first support 40B is similar to the first support 40A, but the wick 30B is made of a porous material. Since the wick 30B is made of a porous material, the capillary force of the wick 30B can be improved.

The porous body constituting the wick 30B is, for example, a porous sintered body such as a porous metal sintered body, a porous ceramic sintered body, or a porous body such as a porous metal body, a porous ceramic body, a porous resin body, etc. One example is the body.

The wick 30B may or may not have a through hole penetrating in the thickness direction Z.

The wick 30B and the first support body 40B can be produced, for example, by a method such as a printing technique using multilayer coating using metal paste or ceramic paste.

FIG. 11 is a sectional view showing a third modification of the wick, sheet member, first support, and second support that constitute the heat diffusion device according to the second embodiment of the present invention.

In the example shown in FIG. 11, the wick 30C and the first support 40C are made of a porous material.

The porous bodies constituting the wick 30C and the first support body 40C 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 30C may or may not have a through hole penetrating in the thickness direction Z.

The wick 30C and the first support 40C can be produced, for example, by a method such as 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 first support 40C may be the same as the content of metal or ceramics in the paste for forming the wick 30C, and The content of metal or ceramics in the paste for forming the wick 30C may be lower than that of the metal or ceramics in the paste for forming the wick 30C. For example, by making the content of metal or ceramics in the paste for forming the first support body 40C larger than the content of metal or ceramics in the paste for forming the wick 30C, the first support body 40C The density of the wick 30C can be made larger than that of the wick 30C. As a result, the strength of the first support body 40C can be increased.

In the heat diffusion device according to the second embodiment of the present invention, the sheet member and the second support can also have the same configuration as the modified example of the wick and the first support described above. That is, the second support body does not need to be recessed like the first support body 40A shown in FIG. In that case, the sheet member may be made of a porous material, like a wick 30B shown in FIG. 10. Alternatively, the sheet member and the second support may be made of a porous body, as in the wick 30C and the first support 40C shown in FIG.

In the heat diffusion device according to the second embodiment of the present invention, the sheet member preferably does not have a porous structure, but may have a porous structure similarly to the wick. In that case, the sheet member may have the same porous structure as the wick, or may have a different porous structure from the wick. When the sheet member has a porous structure, the sheet member may be arranged between the second inner surface and the second support, or between the wick and the second support.

[Other embodiments]
The heat diffusion device of the present invention is not limited to the above-described 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 may be arranged on the outer wall surface of the casing, or a plurality of heat sources may be arranged.

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 and provided with an internal space;
a working medium sealed in the internal space of the housing;
a sheet-like wick disposed in the internal space of the housing;
a sheet member that is disposed in the internal space of the casing and is the same or a different member from the wick;
a plurality of first supports integrated with the wick;
a plurality of second supports integrated with the sheet member;
The wick is spaced apart from the first inner surface via the first support and spaced from the second inner surface via the second support.

<2>
The heat diffusion device according to <1>, wherein the sheet member is the same member as the wick.

<3>
The heat diffusion device according to <1>, wherein the sheet member is a member different from the wick.

<4>
The heat diffusion device according to any one of <1> to <3>, wherein the height of the first support is smaller than the height of the second support.

<5>
The heat diffusion device according to any one of <1> to <4>, wherein the distance between the centers of the adjacent first supports is smaller than the distance between the centers of the adjacent second supports.

<6>
The equivalent circle diameter of the cross section perpendicular to the height direction of the wick side end of the first support is the circle equivalent diameter of the cross section perpendicular to the height direction of the wick side end of the second support. The heat diffusion device according to any one of <1> to <5>, which is smaller.

<7>
The heat diffusion device according to any one of <1> to <6>, wherein the thickness of the first support is the same as the thickness of the wick or smaller than the thickness of the wick.

<8>
The heat diffusion device according to any one of <1> to <7>, wherein the thickness of the second support is the same as the thickness of the sheet member or smaller than the thickness of the sheet member.

<9>
The heat diffusion device according to any one of <1> to <8>, wherein the wick has a plurality of through holes penetrating in the thickness direction.

<10>
The heat diffusion device according to <9>, wherein a convex portion is provided on a peripheral edge of the through hole in a direction approaching the second inner surface.

<11>
The heat diffusion device according to <9> or <10>, wherein a convex portion is provided on a peripheral edge of the through hole in a direction approaching the first inner surface.

<12>
An electronic device comprising the heat diffusion device according to any one of <1> to <11>.

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, 2 Vapor chamber (thermal diffusion device)
10 Housing 11 First sheet 11a First inner surface 12 Second sheet 12a Second inner surface 20 Working medium 30, 30A, 30B, 30C Wick 31 Through hole 32, 33 Convex portion 35 Sheet member 40, 40A, 40B, 40C First Support body 50 Second support body HS Heat source X Width direction Y Length direction Z Thickness direction

Claims (12)

A casing having a first inner surface and a second inner surface facing each other in the thickness direction and provided with an internal space;
a working medium sealed in the internal space of the housing;
a sheet-like wick disposed in the internal space of the housing;
a sheet member that is disposed in the internal space of the casing and is the same as or different from the wick;
a plurality of first supports integrated with the wick;
a plurality of second supports integrated with the sheet member,
A heat spreading device, wherein the wick is spaced from the first inner surface via the first support and spaced from the second inner surface via the second support. The heat diffusion device according to claim 1, wherein the sheet member is the same member as the wick. The heat diffusion device according to claim 1, wherein the sheet member is a member different from the wick. The heat diffusion device according to any one of claims 1 to 3, wherein the height of the first support is smaller than the height of the second support. The heat diffusion device according to any one of claims 1 to 4, wherein the distance between the centers of the adjacent first supports is smaller than the distance between the centers of the adjacent second supports. The equivalent circle diameter of the cross section perpendicular to the height direction of the wick side end of the first support is the circle equivalent diameter of the cross section perpendicular to the height direction of the wick side end of the second support. A heat spreading device according to any one of claims 1 to 5, which is smaller. The heat diffusion device according to any one of claims 1 to 6, wherein the thickness of the first support is the same as the thickness of the wick or smaller than the thickness of the wick. The heat diffusion device according to any one of claims 1 to 7, wherein the thickness of the second support is the same as the thickness of the sheet member or smaller than the thickness of the sheet member. The heat diffusion device according to any one of claims 1 to 8, wherein the wick has a plurality of through holes penetrating in the thickness direction. The heat diffusion device according to claim 9, wherein a periphery of the through hole is provided with a convex portion in a direction approaching the second inner surface. The heat diffusion device according to claim 9 or 10, wherein a periphery of the through hole is provided with a convex portion in a direction approaching the first inner surface. An electronic device comprising the heat diffusion device according to any one of claims 1 to 11.

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