JP7711722B2 - Heat diffusion device and electronic device - Google Patents

Description

The present invention relates to a heat diffusion device and an electronic device.

In recent years, the amount of heat generated has increased due to the high integration and high performance of elements. In addition, the heat density has increased due to the miniaturization of products. This situation is particularly noticeable in the field of mobile terminals such as smartphones and tablets. For these reasons, it has become important to take measures to dissipate heat.

Graphite sheets and other materials are often used as heat dissipation materials, but because their heat transport capacity is insufficient, the use of various heat diffusion devices (e.g., vapor chambers) that can effectively diffuse heat is being considered.

Patent document 1 discloses a vapor chamber configuration that includes a bottom layer, an upper layer, a wick layer (mesh layer), and a vapor layer having multiple supports.

US Patent Application Publication No. 2019/0390919

In the vapor chamber configuration shown in FIG. 7A of Patent Document 1, the support pillars for securing the vapor layer are provided so as to contact both the wavy structure of the upper layer and the wick layer (mesh layer). However, in the vapor chamber configuration shown in FIG. 7A of Patent Document 1, when the wavy structure of the upper layer tries to expand and contract, the expansion and contraction movement of the wavy structure is hindered by the support pillars.

Furthermore, in the vapor chamber configuration shown in FIG. 7A of Patent Document 1, the support pillars are provided in the wavy structure of the upper layer, but it is difficult to provide the support pillars in the wavy structure without impeding the expansion and contraction movement of the wavy structure. In particular, when trying to make the vapor chamber thinner, in order to ensure the expansion and contraction of the wavy structure of the upper layer while suppressing its thickness, it is required to make the wavy structure a fine wavy structure with a small height and pitch, or to reduce the thickness of the upper layer itself, but it is even more difficult to provide support pillars in such a fine wavy structure of the upper layer with a small thickness without impeding the expansion and contraction movement of the wavy structure.

In addition, in the vapor chamber configuration shown in FIG. 7A of Patent Document 1, the support pillars are provided in the wick layer. Here, the wick layer functions as a member for returning the liquid phase working medium to the evaporation section, and since its performance greatly affects the heat transport capacity of the vapor chamber, it is necessary to select a material for the wick layer with appropriate specifications such as pore size and porosity. However, it is difficult to select a material for the wick layer that has the above-mentioned appropriate specifications and can also be provided with support pillars.

For these reasons, it is difficult to provide supports for the wavy structure of the upper layer and the wick layer in the vapor chamber configuration described in Figure 7A of Patent Document 1.

As described above, in conventional vapor chambers such as the configuration shown in FIG. 7A of Patent Document 1, there is room for improvement in terms of a configuration in which the expansion and contraction movement of the bellows structure is not hindered by the supports that support the housing from the internal space side.

The above circumstances are not limited to vapor chambers, but are common to heat diffusion devices that can diffuse heat using a similar configuration to a vapor chamber.

The present invention has been made to solve the above problems, and aims to provide a heat diffusion device in which the expansion and contraction movement of the bellows structure is not hindered by the supports that support the housing from the internal space side. Another aim of the present invention is to provide an electronic device that has the above heat diffusion device.

The heat diffusion device of the present invention comprises a housing having a first inner surface and a second inner surface opposed in a thickness direction and having an internal space, a working medium sealed in the internal space of the housing, a wick provided in the internal space of the housing at a position away from the first inner surface, and a support provided on the second inner surface and penetrating the wick in the thickness direction to reach the first inner surface, the first inner surface including a bellows surface having a bellows structure, and the support is in contact with the bellows surface but is not fixed to the bellows surface.

The electronic device of the present invention is characterized by being equipped with the heat diffusion device of the present invention.

The present invention provides a heat diffusion device in which the expansion and contraction movement of the bellows structure is not hindered by the supports that support the housing from the internal space side. The present invention also provides an electronic device that has the heat diffusion device.

FIG. 1 is a schematic perspective view showing an example of a heat diffusion device according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of the internal structure of the heat spreading device according to the first embodiment of the present invention. FIG. 3 is a schematic plan view showing an example of a part of an arrangement region of the wick and the support columns constituting the heat spreading device according to the first embodiment of the present invention, as viewed from the thickness direction. FIG. 4 is a schematic cross-sectional view showing an example of the internal structure of the heat spreading device according to the second embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing an example of the internal structure of a heat spreading device according to the third embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing another example of the internal structure of the heat spreading device according to the third embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing an example of the internal structure of a heat spreading device according to the fourth embodiment of the present invention. FIG. 8 is a schematic plan view showing an example of a part of an arrangement region of the wick and the support columns constituting the heat spreading device according to the fourth embodiment of the present invention, as viewed from the thickness direction. FIG. 9 is a schematic plan view showing another example of a part of the arrangement area of the wick and the support columns constituting the heat spreading device according to the fourth embodiment of the present invention, as viewed from the thickness direction. FIG. 10 is a schematic cross-sectional view showing an example of the internal structure of the heat spreading device according to the fifth embodiment of the present invention. FIG. 11 is a schematic cross-sectional view showing an example of the internal structure of the heat spreading device according to the sixth embodiment of the present invention. FIG. 12 is a schematic cross-sectional view showing another example of the internal structure of the heat spreading device according to the sixth embodiment of the present invention. FIG. 13 is a schematic plan view showing an example of a part of an arrangement region of the wick and the support columns constituting the heat spreading device according to the seventh embodiment of the present invention, as viewed from the thickness direction. FIG. 14 is a schematic plan view showing another example of a part of the arrangement area of the wick and the support columns constituting the heat spreading device according to the seventh embodiment of the present invention, as viewed from the thickness direction. FIG. 15 is a schematic plan view showing yet another example of a part of the arrangement area of the wick and the support columns constituting the heat spreading device according to the seventh embodiment of the present invention, as viewed from the thickness direction. FIG. 16 is a schematic perspective view showing an example of an electronic device of the present invention.

The heat spreading device of the present invention and the electronic device of the present invention are described below. Note that the present invention is not limited to the configurations below, and may be modified as appropriate without departing from the gist of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

The embodiments shown below are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From embodiment 2 onwards, descriptions of matters common to embodiment 1 will be omitted, and differences will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned one by one for each embodiment.

In the following description, unless otherwise specified, each embodiment will be referred to simply as the "heat spreading device of the present invention" and the "electronic device of the present invention."

In the following embodiments, a vapor chamber is shown as an example of a heat diffusion device of the present invention. The heat diffusion device of the present invention can also be applied to heat diffusion devices such as heat pipes.

The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product.

In this specification, terms indicating the relationship between elements (e.g., "parallel," "perpendicular," etc.) and terms indicating the shape of elements do not only mean the literal strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

[Heat diffusion device]
The heat diffusion device of the present invention comprises a housing having a first inner surface and a second inner surface opposed in a thickness direction and having an internal space, a working medium sealed in the internal space of the housing, a wick provided in the internal space of the housing at a position away from the first inner surface, and a support provided on the second inner surface and penetrating the wick in the thickness direction to reach the first inner surface, wherein the first inner surface includes a bellows surface having a bellows structure, and the support is in contact with the bellows surface but is not fixed to the bellows surface.

The heat diffusion device of the present invention can be freely deformed by utilizing the expansion and contraction of the bellows structure. The characteristics of each embodiment described below may be satisfied before, during, or after the expansion and contraction of the bellows structure.

<Embodiment 1>
FIG. 1 is a schematic perspective view showing an example of a heat diffusion device according to a first embodiment of the present invention.

The vapor chamber (thermal diffusion device) 1A shown in FIG. 1 has a housing 10.

The housing 10 is airtight and has a hollow structure.

A heat source HS, which is a heat generating element, is provided on the outer surface of the housing 10.

Examples of the heat source HS include electronic components.

In this specification, the length direction, thickness direction, and width direction are respectively defined as directions L, T, and W, as shown in FIG. 1 etc. The length direction L, thickness direction T, and width direction W are perpendicular to one another. In addition, the direction perpendicular to the thickness direction T and including the length direction L and width direction W is defined as the surface direction.

It is preferable that the vapor chamber 1A is planar as a whole. In other words, it is preferable that the housing 10 is planar as a whole.

In this specification, planar refers to a shape that includes plate-like and sheet-like shapes, and refers to a shape in which the length and width dimensions are significantly larger than the thickness dimensions, for example, a shape in which the length and width dimensions are 10 times or more, preferably 100 times or more, the thickness dimensions.

The size of the vapor chamber 1A is not particularly limited.

The lengthwise dimension L and widthwise dimension W of the vapor chamber 1A are preferably 5 mm or more and 500 mm or less, more preferably 20 mm or more and 300 mm or less, and even more preferably 50 mm or more and 200 mm or less.

The lengthwise dimension L and widthwise dimension W of the vapor chamber 1A may be the same or different.

The thickness direction T of the vapor chamber 1A is preferably 100 μm or more and 1 mm or less.

The length direction L, thickness direction T, and width direction W dimensions of the vapor chamber 1A are defined as the maximum dimensions in the length direction L, thickness direction T, and width direction W, respectively.

It is preferable that the housing 10 is composed of a first sheet 11 and a second sheet 12 whose outer edges are joined together.

In this specification, the term "sheet" also includes forms such as foil and film.

When the outer edges of the first sheet 11 and the second sheet 12 are joined, the ends may overlap so that they coincide with each other, or the ends may overlap so that they are offset from each other.

It is preferable that the outer edges of the first sheet 11 and the second sheet 12 are directly bonded to each other.

Methods for joining the outer edges of the first sheet 11 and the second sheet 12 include, for example, laser welding, resistance welding, diffusion bonding, soldering, TIG welding (tungsten-inert gas welding), ultrasonic bonding, resin sealing, etc. Among these, laser welding, resistance welding, and soldering are preferred.

The material of the first sheet 11 and the second sheet 12 is not particularly limited as long as it has properties suitable for a heat diffusion device (e.g., vapor chamber 1A), such as thermal conductivity, strength, flexibility, and the like. The material of 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 at least one of these metals as a main component, and is particularly preferably copper or its alloy, aluminum or its alloy, or stainless steel (iron alloy).

The constituent materials of the first sheet 11 and the second sheet 12 may be the same or different.

When the first sheet 11 and the second sheet 12 are made of different materials, the first sheet 11 and the second sheet 12 can have different functions. Such functions include, but are not limited to, a heat conduction function, an electromagnetic wave shielding function, etc.

The dimensions of the first sheet 11 and the second sheet 12 in the thickness direction T are preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 60 μm or less.

The dimensions of the first sheet 11 and the second sheet 12 in the thickness direction T may be the same or different.

The dimensions of the first sheet 11 and the second sheet 12 in the thickness direction T are each determined as the maximum dimensions in the thickness direction T.

The dimensions of the first sheet 11 and the second sheet 12 in the thickness direction T may be the same throughout or may differ in some areas.

The planar shape of the housing 10 when viewed from the thickness direction T may be, for example, a polygon such as a triangle or a rectangle, a circle, an ellipse, or a combination of these. The planar shape of the housing 10 may be an L-shape, a C-shape, a step shape, or the like. The housing 10 may also have a through hole in the thickness direction T. The planar shape of the housing 10 may be a shape according to the use of the heat diffusion device (e.g., vapor chamber 1A), a shape according to the mounting location of the heat diffusion device (e.g., vapor chamber 1A), or a shape according to other components present in the vicinity.

The size of the housing 10 is not particularly limited.

The dimensions of the length direction L and width direction W of the housing 10 are preferably 5 mm or more and 500 mm or less, more preferably 20 mm or more and 300 mm or less, and even more preferably 50 mm or more and 200 mm or less.

The lengthwise dimension L and widthwise dimension W of the housing 10 may be the same or different.

The dimension of the housing 10 in the thickness direction T is preferably 100 μm or more and 1 mm or less.

The dimensions of the length direction L, thickness direction T, and width direction W of the housing 10 are defined as the maximum dimensions of the length direction L, thickness direction T, and width direction W, respectively.

In FIG. 1, an example is shown in which the housing 10 is made up of two sheets, a first sheet 11 and a second sheet 12, but the housing 10 may be made up of one sheet or three or more sheets.

Figure 2 is a schematic cross-sectional view showing an example of the internal structure of a heat diffusion device according to embodiment 1 of the present invention.

The vapor chamber 1A shown in FIG. 2 has a housing 10, a working medium 20, a wick 30, and a support 40a.

As shown in FIG. 2, the housing 10 has a first inner surface 10a and a second inner surface 10b that face each other in the thickness direction T.

In the example shown in FIG. 2, the housing 10 is composed of a first sheet 11 and a second sheet 12, with the inner surface of the first sheet 11 corresponding to the first inner surface 10a and the inner surface of the second sheet 12 corresponding to the second inner surface 10b.

As shown in FIG. 2, the first inner surface 10a includes a bellows surface 15a having a bellows structure. The outer surface opposite the first inner surface 10a, in this case the outer surface opposite the inner surface of the first sheet 11, also includes a bellows surface having a bellows structure at a position opposite the bellows surface 15a. In this way, the first sheet 11 is provided with a bellows structure.

In this specification, the bellows structure includes not only a structure in which the sheet is folded in a mountain fold and a valley fold, resulting in convex and concave portions with folded corners (sharp corners) lined up in one direction, but also a wavy structure in which the sheet is bent in a meandering manner, resulting in convex and concave portions without folded corners (sharp corners) lined up in one direction.

The vapor chamber 1A can be deformed by utilizing the expansion and contraction of the bellows structure of the bellows surface 15a.

As shown in FIG. 2, the bellows surface 15a has a convex portion 16a and a concave portion 17a.

In the example shown in FIG. 2, there are multiple convex portions 16a and multiple concave portions 17a, which are arranged alternately in the length direction L.

For convex portions 16a and concave portions 17a adjacent to each other in the surface direction (length direction L in FIG. 2), the distance (height) in the thickness direction T between the tip of convex portion 16a and the bottom end of concave portion 17a is preferably 2 mm or less, and more preferably 1 mm or less.

When there are multiple convex portions 16a and multiple concave portions 17a as shown in FIG. 2, the multiple convex portions 16a and multiple concave portions 17a may be present such that the distance in the thickness direction T between the tip of the convex portion 16a and the bottom end of the concave portion 17a is constant throughout for the convex portions 16a and the concave portions 17a adjacent to each other in the surface direction, or may be present such that the distance in the thickness direction T between the tip of the convex portion 16a and the bottom end of the concave portion 17a is not constant at least in part.

The center-to-center distance (pitch) between the tips of adjacent convex portions 16a in the surface direction (length direction L in FIG. 2) is preferably 2 mm or less, and more preferably 1 mm or less.

When multiple protrusions 16a are present as shown in FIG. 2, the multiple protrusions 16a may be present such that the center-to-center distance between the tips of adjacent protrusions 16a in the surface direction is constant throughout, or may be present such that the center-to-center distance between the tips of adjacent protrusions 16a in the surface direction is not constant at least in part.

The center-to-center distance (pitch) between the bottom ends of adjacent recesses 17a in the surface direction (length direction L in FIG. 2) is preferably 2 mm or less, and more preferably 1 mm or less.

When multiple recesses 17a are present as shown in FIG. 2, the multiple recesses 17a may be present such that the center-to-center distance between the bottom ends of adjacent recesses 17a in the surface direction is constant throughout, or the center-to-center distance between the bottom ends of adjacent recesses 17a in the surface direction is not constant at least in part.

The bellows surface 15a may be present on at least a portion of the first inner surface 10a. In other words, the bellows surface 15a may be present on the entire first inner surface 10a, or may be present on only a portion of the first inner surface 10a. When the bellows surface 15a is present on only a portion of the first inner surface 10a, it is preferable that the bellows surface 15a is present in an area excluding the outer edge of the first inner surface 10a.

The second sheet 12 may be, for example, a flat plate with a constant dimension in the thickness direction T, or may have a shape in which the outer edge has a larger dimension in the thickness direction T than the rest of the outer edge. Alternatively, the second sheet 12 may have a constant dimension in the thickness direction T, and the rest of the sheet may have a shape that is convex outward relative to the outer edge. In this case, a recess is provided in the outer edge of the housing 10. Such a recess in the outer edge of the housing 10 can be used when mounting a heat diffusion device (e.g., vapor chamber 1A). Other components can also be placed in the recess in the outer edge of the housing 10.

The housing 10 has an internal space. More specifically, the housing 10 has an internal space surrounded by a first inner surface 10a and a second inner surface 10b.

It is preferable that the housing 10 has an evaporation section in its internal space.

The evaporation section is a section that evaporates the liquid-phase working medium 20 described below and changes it into a gas-phase working medium 20. More specifically, the evaporation section is a portion of the internal space of the housing 10 that is adjacent to the heat source HS shown in FIG. 1 and corresponds to a portion that is heated by the heat source HS.

The number of evaporation sections may be one or more depending on the number of heat sources HS. In other words, the outer surface of the housing 10 may be provided with one or more heat sources HS.

If the surface on which the heat source is provided has a bellows structure, the contact area between the heat source and the heat diffusion device (e.g., vapor chamber) will be small, resulting in high thermal resistance. In addition, one of the features of a heat diffusion device (e.g., vapor chamber) is that there are no restrictions on the contact position with the heat source, so a configuration in which the surface on which the heat source is provided has a bellows structure is not preferable.

For the above reasons, it is preferable that the heat source HS is not provided on the outer surface opposite the inner surface of the first sheet 11 having the bellows structure, i.e., the outer surface opposite the first inner surface 10a.

On the other hand, the heat source HS is preferably provided on the outer surface opposite the inner surface of the second sheet 12, i.e., the outer surface opposite the second inner surface 10b. In this case, it is preferable that the second sheet 12 does not have a bellows structure. In other words, it is preferable that the second inner surface 10b does not include a bellows surface having a bellows structure.

As shown in FIG. 2, the working medium 20 is sealed in the internal space of the housing 10.

The working medium 20 is not particularly limited as long as it can undergo a gas-liquid phase change in the environment inside the housing 10. Examples of the working medium 20 include water, alcohols, and alternative fluorocarbons. The working medium 20 is preferably an aqueous compound, and among these, water is particularly preferred.

As shown in FIG. 2, the wick 30 is provided in the internal space of the housing 10 at a position away from the first inner surface 10a.

The space between the wick 30 and the first inner surface 10a functions as a vapor flow path that mainly contains the gas phase working medium 20. Here, the vapor flow path may contain the liquid phase working medium 20 as long as it is an area where the gas phase working medium 20 is mainly present.

As shown in FIG. 2, the wick 30 may be provided in the internal space of the housing 10 at a position where it contacts the second inner surface 10b. In this case, it is preferable that the wick 30 is bonded to the second inner surface 10b. Examples of methods for bonding the wick 30 to the second inner surface 10b include diffusion bonding, ultrasonic bonding, spot welding, etc.

The wick 30 may be provided at a position away from the second inner surface 10b in the internal space of the housing 10. In this case, a microchannel that functions as a liquid flow path for the liquid phase working medium 20 may be provided between the wick 30 and the second inner surface 10b. It is preferable that the microchannel is provided on the second inner surface 10b and is in contact with the wick 30.

The wick 30 has a capillary structure that can move the liquid phase working medium 20 by capillary force.

The capillary structure of the wick 30 may be a known structure used in conventional heat diffusion devices (e.g., vapor chambers). Such capillary structures include microstructures having irregularities such as pores, grooves, and protrusions, such as porous structures, fibrous structures, groove structures, and mesh structures.

The wick 30 functions as a liquid transport section that sucks up and transports the liquid phase working medium 20 by capillary force.

In the example shown in FIG. 2, the wick 30 functions as a liquid flow path that mainly contains the liquid phase working medium 20. Here, the liquid flow path may contain the gas phase working medium 20 as long as it is an area where the liquid phase working medium 20 is mainly present.

It is preferable that the wick 30 be planar.

It is preferable that the wick 30 be made of a porous material.

Examples of porous bodies include sintered bodies, nonwoven fabrics, meshes, etched porous plates, fiber bundles, etc.

Examples of sintered bodies include porous metal sintered bodies and porous ceramic sintered bodies. Among these, porous metal sintered bodies are preferred, and porous copper or nickel sintered bodies are more preferred.

Examples of nonwoven fabrics include metal nonwoven fabrics. When the wick 30 is made of nonwoven fabric, it can be produced inexpensively.

Examples of the mesh include metal mesh, resin mesh, and surface-coated versions of these meshes. Among these, copper mesh, stainless steel (SUS) mesh, and polyester mesh are preferred. When the wick 30 is made of mesh, it can be produced inexpensively.

The etched porous plate is produced, for example, by etching a flat metal plate. When the wick 30 is made of an etched porous plate produced in this manner, it has excellent flatness.

The fiber bundle is produced, for example, by bundling multiple fibers into a linear shape. The fiber bundle functions as a liquid holding section that sucks up and holds the liquid phase working medium 20 by capillary force, and also functions as a liquid transport section that transports the sucked up liquid phase working medium 20.

When the wick 30 is made of a fiber bundle, it is preferable that the wick 30 is made of a braided fiber bundle. A braided fiber bundle in which multiple fibers are woven is likely to have uneven surfaces, so when the wick 30 is made of a braided fiber bundle, the liquid phase working medium 20 is more easily transported.

Examples of fibers that make up the fiber bundle include metal wires such as copper, aluminum, and stainless steel, and non-metallic wires such as carbon fiber and glass fiber. Among these, metal wires are preferred because of their high thermal conductivity. For example, a fiber bundle can be made by bundling about 200 copper wires with a diameter of about 0.03 mm.

The dimension of the wick 30 in the thickness direction T is preferably 2 μm or more and 200 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 40 μm or less.

The dimension of the wick 30 in the thickness direction T is defined as the maximum dimension in the thickness direction T.

The dimension of the wick 30 in the thickness direction T may be the same throughout or may differ in some areas.

As shown in FIG. 2, the support 40a is provided on the second inner surface 10b.

In the example shown in FIG. 2, the support 40a is provided so as to protrude in the thickness direction T from the second inner surface 10b toward the first inner surface 10a.

The support 40a may be integrated with the second inner surface 10b. In other words, the support 40a may be formed by a portion extending from the second inner surface 10b, here the inner surface of the second sheet 12. In this case, the support 40a is formed, for example, by performing etching, pressing, or the like on the second inner surface 10b, here the inner surface of the second sheet 12.

In this specification, two elements being integrated means that there is no interface between the elements, for example, the boundary between the elements cannot be distinguished.

The pillars 40a may be joined to the second inner surface 10b. In this case, the pillars 40a are formed by joining, for example, a columnar member to the second inner surface 10b, in this case the inner surface of the second sheet 12, by a joining method such as welding or diffusion bonding.

In addition, from the viewpoint of preventing the complexity of assembly and the increase in costs due to an increase in the number of parts, among the above-mentioned configurations of the support 40a, the configuration in which the support 40a is integrated with the second inner surface 10b is preferable.

As shown in FIG. 2, the support 40a penetrates the wick 30 in the thickness direction T and reaches the first inner surface 10a.

Since the support pillars 40a provided on the second inner surface 10b reach the first inner surface 10a, the first inner surface 10a and the second inner surface 10b are supported by the support pillars 40a, and the housing 10 is supported from the internal space side by the support pillars 40a. Therefore, even if external pressure is applied to the housing 10, the vapor flow path between the wick 30 and the first inner surface 10a is not easily crushed, and the vapor flow path is secured. As a result, the permeability of the gas-phase working medium 20 through the vapor flow path is secured.

Methods for realizing a configuration in which the support 40a penetrates the wick 30 in the thickness direction T include, for example, a method in which a through hole penetrating the wick 30 in the thickness direction T is provided in advance, and then the support 40a is inserted into the through hole, or a method in which the support 40a is inserted into the wick 30 in the thickness direction T.

In this embodiment, when multiple pillars 40a are provided as shown in FIG. 2, at least one of the multiple pillars 40a may penetrate the wick 30 in the thickness direction T and reach the first inner surface 10a. In other words, in this embodiment, all of the multiple pillars 40a may penetrate the wick 30 in the thickness direction T and reach the first inner surface 10a, or some of the pillars 40a may penetrate the wick 30 in the thickness direction T and reach the first inner surface 10a.

In this embodiment, if some of the multiple pillars 40a penetrate the wick 30 in the thickness direction T and reach the first inner surface 10a, the remaining pillars 40a may include pillars that do not penetrate the wick 30 in the thickness direction T, or may include pillars that penetrate the wick 30 in the thickness direction T but do not reach the first inner surface 10a.

As shown in FIG. 2, the support 40a contacts the bellows surface 15a.

Since the support 40a is in contact with the bellows surface 15a, the housing 10 is supported from the internal space side by the support 40a. Therefore, even if external pressure is applied to the housing 10, the vapor flow path between the wick 30 and the first inner surface 10a is not easily crushed. As a result, the vapor flow path ensures sufficient permeability of the gas-phase working medium 20.

The support 40a may contact the tip of the convex portion 16a with respect to the bellows surface 15a, or may contact a portion other than the tip of the convex portion 16a.

The tip of the support 40a may contact the bellows surface 15a, or a portion of the support 40a other than the tip may contact the bellows surface 15a.

As shown in FIG. 2, the support 40a is not fixed to the bellows surface 15a.

In this specification, the phrase "the support pillars are not fixed to the bellows surface" means that the support pillars are not integrated with the bellows surface, and are not fixed to the bellows surface by any method such as joining.

In this embodiment, when multiple support columns 40a are provided as shown in FIG. 2, at least one of the multiple support columns 40a may be in contact with the bellows surface 15a and not fixed to the bellows surface 15a. In other words, in this embodiment, all of the multiple support columns 40a may be in contact with the bellows surface 15a and not fixed to the bellows surface 15a, or some of the support columns 40a may be in contact with the bellows surface 15a and not fixed to the bellows surface 15a.

In this embodiment, if some of the multiple pillars 40a are in contact with the bellows surface 15a and are not fixed to the bellows surface 15a, the remaining pillars 40a do not need to be in contact with the bellows surface 15a.

As described above, in the vapor chamber 1A, the support pillars 40a are in contact with the bellows surface 15a but are not fixed to the bellows surface 15a. This allows the support pillars 40a and the bellows surface 15a to change their relative positions even if the bellows structure of the bellows surface 15a expands and contracts, so the expansion and contraction movement of the bellows structure of the bellows surface 15a is not hindered by the support pillars 40a.

Therefore, the vapor chamber 1A can realize a heat diffusion device in which the expansion and contraction movement of the bellows structure is not hindered by the support pillars 40a that support the housing 10 from the internal space side. Therefore, even if the support pillars 40a are provided, the vapor chamber 1A can be freely deformed by utilizing the expansion and contraction of the bellows structure.

Furthermore, in the vapor chamber 1A, the support 40a is provided on the second inner surface 10b so as to penetrate the wick 30 in the thickness direction T, so there is no need to provide the support 40a on the bellows surface 15a and the wick 30, where it is difficult to provide the support. Therefore, for example, when trying to make the vapor chamber 1A thinner, in order to ensure the elasticity of the bellows structure while suppressing the thickness of the bellows structure, even if the bellows surface 15a has a fine bellows structure with a small height and pitch, the difficulty of providing the support 40a on the bellows surface 15a can be avoided. In addition, in the vapor chamber 1A, since there is no need to provide the support 40a on the wick 30, the difficulty of selecting a material for the wick 30 that has appropriate specifications (e.g., pore size, porosity, etc.) that do not significantly affect the heat transport capacity of the vapor chamber 1A and can provide the support 40a can be avoided.

Figure 3 is a schematic plan view showing an example of a portion of the arrangement area of the wick and support pillars constituting the heat diffusion device of embodiment 1 of the present invention, as viewed from the thickness direction.

In the example shown in Figure 3, multiple support pillars 40a are provided.

When viewed from the thickness direction T as shown in FIG. 3, the multiple supports 40a may be arranged in a lattice (matrix), a staggered pattern, or any other arrangement.

As shown in FIG. 3, when viewed from the thickness direction T, the multiple pillars 40a may be evenly spaced so that the center-to-center distance (pitch) of adjacent pillars 40a in the surface direction is constant throughout, or may be unevenly spaced so that the center-to-center distance of adjacent pillars 40a in the surface direction is not constant at least in part.

When viewed from the thickness direction T as shown in FIG. 3, the multiple support columns 40a may be provided on the entire second inner surface 10b, or may be provided on only a portion of the second inner surface 10b.

Examples of materials that make up the support 40a include metal, resin, ceramics, and mixtures or laminates of two or more of these materials.

The material of the support 40a is preferably the same as the material of the housing 10, in this case the material of the second sheet 12 on which the support 40a is provided, but may be different from the material of the second sheet 12.

When multiple supports 40a are provided as shown in Figures 2 and 3, the constituent materials of the multiple supports 40a may be the same as each other, may be different from each other, or may be partially different.

The support 40a may be made of a single layer or multiple layers.

The planar shape of the support 40a when viewed from the thickness direction T can be, for example, a polygon such as a triangle or a rectangle, a circle, an ellipse, or a combination of these.

When multiple pillars 40a are provided as shown in Figures 2 and 3, the planar shapes of the multiple pillars 40a may be the same as each other, may be different from each other, or may be partially different.

The cross-sectional shape of the support 40a when viewed from the surface direction can be, for example, a polygon such as a rectangle. The cross-sectional shape of the support 40a can be a shape in which the dimension in the surface direction is constant from the second inner surface 10b side to the first inner surface 10a side, or a tapered shape in which the dimension in the surface direction decreases from the second inner surface 10b side to the first inner surface 10a side.

When multiple pillars 40a are provided as shown in Figures 2 and 3, the cross-sectional shapes of the multiple pillars 40a may be the same as each other, may be different from each other, or may be partially different.

The dimension of the support 40a in the planar direction (e.g., the dimension in the length direction L in Figs. 2 and 3), converted into the circle-equivalent diameter of the cross section along the planar direction at the end of the support 40a in the thickness direction T, is, for example, 100 μm or more and 2000 μm or less, and preferably 300 μm or more and 1000 μm or less. When the planar dimension of the support 40a is large, the vapor flow path between the wick 30 and the first inner surface 10a is less likely to collapse even if external pressure is applied to the housing 10. When the planar dimension of the support 40a is small, it is easier to ensure a wide vapor flow path between the wick 30 and the first inner surface 10a.

When multiple pillars 40a are provided as shown in Figures 2 and 3, the dimensions of the multiple pillars 40a in the planar direction may be the same as each other, may be different from each other, or may be partially different.

When multiple pillars 40a are provided as shown in Figures 2 and 3, the dimensions of the multiple pillars 40a in the thickness direction T may be the same as each other, may be different from each other, or may be partially different.

The dimensions, shape, number, arrangement, etc. of the support pillars 40a may differ from the examples shown in Figures 2 and 3 in the actual product.

The vapor chamber 1A operates as follows:

In the vapor chamber 1A, the liquid phase working medium 20 evaporates by absorbing heat from the heat source HS in the wick 30 (liquid flow path) present in the region near the evaporation section (heat source HS), and changes into the gas phase working medium 20. The gas phase working medium 20 generated in the evaporation section moves through the vapor flow path between the wick 30 and the first inner surface 10a to a region away from the evaporation section, for example, around the end opposite the evaporation section in the length direction L of the vapor flow path, where it is cooled and changes into the liquid phase working medium 20. Hereinafter, the part where the gas phase working medium 20 condenses and changes into the liquid phase working medium 20 is referred to as the condensation section. The condensation section is likely to be located in a region away from the evaporation section, for example, around the end opposite the evaporation section in the length direction L of the internal space of the housing 10. The liquid phase working medium 20 generated in the condensation section is collected by the wick 30 and then transported to the evaporation section.

In the vapor chamber 1A, the above process is repeated, causing the working medium 20 to circulate while undergoing a phase change between gas and liquid. At this time, heat from the heat source HS is absorbed as latent heat of evaporation that changes the liquid phase working medium 20 to the gas phase working medium 20 in the evaporation section, and is then released as latent heat of condensation that changes the gas phase working medium 20 to the liquid phase working medium 20 in the condensation section (e.g., an area away from the evaporation section). In this way, the vapor chamber 1A operates independently without requiring external power, and furthermore, by utilizing the latent heat of evaporation and latent heat of condensation of the working medium 20, the heat from the heat source HS can be diffused two-dimensionally at high speed.

In the vapor chamber 1A, the internal space of the housing 10 may be depressurized to promote evaporation of the liquid phase working medium 20. In this case, the housing 10 is subjected to pressure in a direction in which the internal space is crushed by atmospheric pressure. In particular, when attempting to make the vapor chamber 1A thinner, it is required to reduce the thickness of the first sheet 11 and the second sheet 12, so that the internal space of the housing 10 is more likely to be crushed by the above-mentioned pressure being applied to the housing 10. In contrast, in the vapor chamber 1A, since the support 40a that supports the housing 10 from the internal space side is provided, even if the housing 10 is subjected to the above-mentioned pressure, the internal space of the housing 10 is less likely to be crushed. Furthermore, as described above, in the vapor chamber 1A, even if the support 40a that supports the housing 10 from the internal space side is provided, the expansion and contraction movement of the bellows structure of the bellows surface 15a is not hindered by the support 40a.

<Embodiment 2>
In the heat spreading device of the second embodiment of the present invention, the bellows surface includes a protrusion whose tip is in contact with the support in the thickness direction. The heat spreading device of the second embodiment of the present invention is similar to the heat spreading device of the first embodiment of the present invention except for the above points.

Figure 4 is a schematic cross-sectional view showing an example of the internal structure of a heat diffusion device according to embodiment 2 of the present invention.

In the vapor chamber 1B shown in FIG. 4, the bellows surface 15a includes a protruding portion 16a whose tip contacts the support 40a in the thickness direction T. In other words, in the vapor chamber 1B, there is a support 40a that contacts the tip of the protruding portion 16a in the thickness direction T.

In the vapor chamber 1B, the support 40a contacts the tip of the protrusion 16a in the thickness direction T, so that the support 40a can effectively support the housing 10 from the internal space side without impeding the expansion and contraction movement of the bellows structure of the bellows surface 15a.

As shown in FIG. 4, it is preferable that the bellows surface 15a includes a protrusion 16a whose tip contacts the tip of the support 40a in the thickness direction T. In this case, the support 40a can more effectively support the housing 10 from the internal space side.

On the other hand, while the pillars 40a support the housing 10 from the internal space side, thereby ensuring a vapor flow path between the wick 30 and the first inner surface 10a, they can also impede the flow of the gas phase working medium 20 in the vapor flow path and the flow of the liquid phase working medium 20 in the wick 30, thereby reducing the heat transport capacity. Therefore, from the standpoint of heat transport capacity, the more pillars 40a there are, the more effective they are.

In view of the above, in this embodiment, when there are multiple protrusions 16a as shown in FIG. 4, it is sufficient that the support pillars 40a are provided individually at positions that contact the tip of at least one of the protrusions 16a in the thickness direction T. In this embodiment, from the viewpoint of effectively supporting the housing 10 from the internal space side, the support pillars 40a may be provided individually at positions that contact the tip of all of the protrusions 16a in the thickness direction T. Alternatively, in this embodiment, from the viewpoint of suppressing a decrease in heat transport capacity, the support pillars 40a may not be provided individually at positions that contact the tip of all of the protrusions 16a in the thickness direction T, and more specifically, the support pillars 40a may not be provided individually at positions that contact the tip of some of the protrusions 16a in the thickness direction T.

In addition, in this embodiment, when multiple pillars 40a are provided as shown in FIG. 4, at least one of the multiple pillars 40a may be in contact with the tip of each of the convex portions 16a in the thickness direction T. In other words, in this embodiment, all of the multiple pillars 40a may be in contact with the tip of each of the convex portions 16a in the thickness direction T, or some of the pillars 40a may be in contact with the tip of each of the convex portions 16a in the thickness direction T.

<Embodiment 3>
In the heat spreading device of the third embodiment of the present invention, the bellows surface includes a convex portion having a flat tip. The heat spreading device of the third embodiment of the present invention is similar to the heat spreading devices of the first and second embodiments of the present invention except for the above points.

Figure 5 is a schematic cross-sectional view showing an example of the internal structure of a heat diffusion device according to embodiment 3 of the present invention.

In the vapor chamber 1C shown in FIG. 5, the bellows surface 15b includes a convex portion 16b with a flat tip.

In the vapor chamber 1C, the bellows surface 15b includes a convex portion 16b with a flat tip, and when the support 40a is in contact with the tip of the convex portion 16b as shown in FIG. 5, the contact area between the support 40a and the convex portion 16b is large, so the housing 10 is stably supported from the internal space side by the support 40a. Furthermore, in the vapor chamber 1C, because the contact area between the support 40a and the convex portion 16b is large, even if the positional relationship between the support 40a and the convex portion 16b changes due to the expansion and contraction of the bellows structure of the bellows surface 15b, the state in which the support 40a is in contact with the tip of the convex portion 16b is easily maintained, and as a result, the housing 10 is stably supported from the internal space side by the support 40a.

The tip of the flat convex portion 16b may be completely flat like a mirror surface, or may have a rough shape, so long as the shape can be considered substantially flat.

In this embodiment, when there are multiple convex portions 16b as shown in FIG. 5, it is sufficient that the tip of at least one of the multiple convex portions 16b is flat. In other words, in this embodiment, the tips of all of the multiple convex portions 16b may be flat, or the tips of some of the convex portions 16b may be flat.

The bellows surface 15b includes a recess 17b with a flat tip.

When there are multiple recesses 17b as shown in FIG. 5, the bottom end of at least one of the multiple recesses 17b may be flat. In other words, the bottom ends of all of the multiple recesses 17b may be flat, or the bottom ends of some of the recesses 17b may be flat.

For convex portions 16b and concave portions 17b adjacent to each other in the surface direction (length direction L in FIG. 5), the surface dimension of the tip (flat portion) of convex portion 16b and the surface dimension of the bottom end (flat portion) of concave portion 17b may be the same as or different from each other.

For a convex portion 16b and a concave portion 17b adjacent to each other in the surface direction, if the dimension in the surface direction of the tip of the convex portion 16b is different from the dimension in the surface direction of the bottom end of the concave portion 17b, the dimension in the surface direction of the tip of the convex portion 16b may be smaller or larger than the dimension in the surface direction of the bottom end of the concave portion 17b.

The embodiment in which the bellows surface includes a convex portion with a flat tip is not limited to the example shown in FIG. 5.

Figure 6 is a schematic cross-sectional view showing another example of the internal structure of a heat diffusion device according to embodiment 3 of the present invention.

In the vapor chamber 1C' shown in FIG. 6, the bellows surface 15c includes a convex portion 16c with a flat tip. On the other hand, the bottom end of the concave portion 17c in the bellows surface 15c is not flat.

In the vapor chamber 1C', the effect of the convex portion 16c, the configuration when there are multiple convex portions 16c, and the configuration when there are multiple concave portions 17c are the same as those of the vapor chamber 1C described above, except that the bottom end of the concave portion 17c is not flat.

<Embodiment 4>
In the heat spreading device of the fourth embodiment of the present invention, a gap is provided between the wick and the support in a plane direction perpendicular to the thickness direction. The heat spreading device of the fourth embodiment of the present invention is similar to the heat spreading devices of the first to third embodiments of the present invention except for the above points.

Figure 7 is a schematic cross-sectional view showing an example of the internal structure of a heat diffusion device according to embodiment 4 of the present invention.

In the vapor chamber 1D shown in FIG. 7, a gap 50 is provided between the wick 30 and the support 40a in the planar direction.

In the vapor chamber 1D, when the bellows structure of the bellows surface 15a expands and contracts, the positional relationship between the wick 30 and the support 40a in the surface direction changes. In the vapor chamber 1D, a gap 50 is provided between the wick 30 and the support 40a in the surface direction, and the change in the positional relationship between the wick 30 and the support 40a in the surface direction is absorbed by the gap 50, thereby suppressing the load on the wick 30 and the support 40a.

In this embodiment, when multiple pillars 40a are provided as shown in FIG. 7, it is sufficient that at least one of the multiple pillars 40a has a gap 50 between it and the wick 30 in the surface direction. In other words, in this embodiment, all of the multiple pillars 40a may have a gap 50 between them and the wick 30 in the surface direction, or some of the pillars 40a may have a gap 50 between them and the wick 30 in the surface direction.

Figure 8 is a schematic plan view showing an example of a portion of the arrangement area of the wick and support pillars constituting the heat diffusion device of embodiment 4 of the present invention, as viewed from the thickness direction. Figure 9 is a schematic plan view showing another example of a portion of the arrangement area of the wick and support pillars constituting the heat diffusion device of embodiment 4 of the present invention, as viewed from the thickness direction.

When the vapor chamber 1D deforms, the positional relationship between the wick 30 and the support 40a changes in the direction in which the bellows structure of the bellows surface 15a expands and contracts (length direction L in Figures 7, 8, and 9), so it is preferable that the gap 50 be large in the expansion and contraction direction of the bellows structure in the surface direction.

In this specification, the expansion and contraction direction of the bellows structure refers to the direction in which the convex and concave portions that make up the bellows structure are aligned (here, the surface direction). For example, in a bellows structure formed by mountain folds and valley folds of a sheet, this means the direction perpendicular to the mountain fold lines and valley fold lines when viewed from the thickness direction.

As shown in FIG. 8, when viewed from the thickness direction T, the gaps 50 may be provided with equal size around the pillars 40a. In this case, if the gaps 50 are made larger overall in the planar direction so that the gaps 50 can easily absorb changes in the positional relationship between the wick 30 and the pillars 40a, the liquid flow path may become smaller due to the reduction in the area where the wick 30 is disposed, or the vapor flow path may become smaller due to the reduction in the area where the pillars 40a are disposed, which may result in a decrease in heat transport capacity.

In contrast, as shown in FIG. 9, when viewed from the thickness direction T, the gaps 50 are preferably provided with unequal sizes around the support 40a so that they are relatively long in the expansion and contraction direction of the bellows structure (length direction L in FIG. 9) among the surface directions. More specifically, as shown in FIG. 9, when viewed from the thickness direction T, the gaps 50 are preferably provided with unequal sizes around the support 40a so that they are longer in the expansion and contraction direction of the bellows structure (length direction L in FIG. 9) among the surface directions than in the direction perpendicular to the expansion and contraction direction of the bellows structure (width direction W in FIG. 9). In other words, the distance between the inner peripheral end and the outer peripheral end of the gap 50 is preferably longer in the expansion and contraction direction of the bellows structure than in the direction perpendicular to the expansion and contraction direction of the bellows structure. In this case, the gap 50 is more likely to effectively absorb changes in the positional relationship between the wick 30 and the support 40a while suppressing a decrease in heat transport capacity.

When multiple pillars 40a are provided as shown in Figures 8 and 9, the gaps 50 may be uniformly sized around the periphery for all of the multiple pillars 40a, or may be unequally sized around the periphery for all of the multiple pillars 40a. Alternatively, the gaps 50 may be uniformly sized around the periphery for some of the multiple pillars 40a, and unequally sized around the periphery for the remaining pillars 40a.

<Embodiment 5>
In the heat spreading device of the fifth embodiment of the present invention, the tips of the supports are rounded. The heat spreading device of the fifth embodiment of the present invention is similar to the heat spreading devices of the first to fourth embodiments of the present invention except for the above points.

Figure 10 is a schematic cross-sectional view showing an example of the internal structure of a heat diffusion device according to embodiment 5 of the present invention.

In the vapor chamber 1E shown in Figure 10, the tip of the support 40b is rounded.

In the vapor chamber 1E, when the bellows structure of the bellows surface 15a expands and contracts, the positional relationship between the support 40b and the bellows surface 15a changes. In the vapor chamber 1E, the tip of the support 40b is rounded, so that when the positional relationship between the support 40b and the bellows surface 15a changes, the bellows surface 15a is less likely to get caught on the tip of the support 40b, and the expansion and contraction movement of the bellows structure is less likely to be hindered by the support 40b. Furthermore, in the vapor chamber 1E, the tip of the support 40b is rounded, so when the positional relationship between the support 40b and the bellows surface 15a changes, the bellows surface 15a is less likely to be damaged by the tip of the support 40b, and the housing 10 is less likely to be damaged (for example, less likely to be punctured or torn).

The rounded tip of the support 40b may be, for example, hemispherical or may be of any other shape, so long as it can be said to be a rounded shape that is substantially composed of curves.

In this embodiment, when multiple support columns 40b are provided as shown in FIG. 10, it is sufficient that the tip of at least one of the multiple support columns 40b is rounded. In other words, in this embodiment, the tips of all of the multiple support columns 40b may be rounded, or the tips of some of the support columns 40b may be rounded.

For at least one of the multiple pillars 40b that has a rounded tip, the shape of the rounded tip of each pillar 40b may be the same as each other, may be different from each other, or may be partially different.

<Embodiment 6>
In the heat spreading device of the sixth embodiment of the present invention, the tip of the support is flat. The heat spreading device of the sixth embodiment of the present invention is similar to the heat spreading devices of the first to fourth embodiments of the present invention except for the above points.

Figure 11 is a schematic cross-sectional view showing an example of the internal structure of a heat diffusion device according to embodiment 6 of the present invention.

In the vapor chamber 1F shown in Figure 11, the tip of the support 40c is flat.

In the vapor chamber 1F, the tip of the support 40c is flat, so that the support 40c comes into contact with the bellows surface 15a, and the housing 10 is stably supported from the internal space side by the support 40c.

In this embodiment, when multiple pillars 40c are provided as shown in FIG. 11, it is sufficient that the tip of at least one of the multiple pillars 40c is flat. In other words, in this embodiment, the tips of all of the multiple pillars 40c may be flat, or the tips of some of the pillars 40c may be flat.

As shown in FIG. 11, it is preferable that the corners at the tips of the support posts 40c have a chamfered shape.

In the example shown in FIG. 11, the corners at the tips of the support posts 40c have a rounded chamfered shape.

In the vapor chamber 1F, when the bellows structure of the bellows surface 15a expands and contracts, the positional relationship between the support 40c and the bellows surface 15a changes. In the vapor chamber 1F, the corners of the tips of the support 40c are chamfered, so that when the positional relationship between the support 40c and the bellows surface 15a changes, the bellows surface 15a is less likely to get caught on the corners of the tips of the support 40c, and the expansion and contraction movement of the bellows structure is less likely to be hindered by the support 40c. Furthermore, in the vapor chamber 1F, the corners of the tips of the support 40c are chamfered, so that when the positional relationship between the support 40c and the bellows surface 15a changes, the bellows surface 15a is less likely to be damaged by the corners of the tips of the support 40c, and the housing 10 is less likely to be damaged (for example, less likely to be punctured or torn).

When multiple support columns 40c are provided as shown in FIG. 11, it is preferable that the corner of the tip of at least one of the multiple support columns 40c has a chamfered shape. In this case, the corners of the tips of all of the multiple support columns 40c may have a chamfered shape, or the corners of the tips of some of the support columns 40c may have a chamfered shape.

When at least one of the multiple pillars 40c has a chamfered tip corner, the shapes of the tip corners of at least one of the pillars 40c having a chamfered tip corner may be the same as each other, may be different from each other, or may be partially different.

The embodiment in which the tip of the support is flat and the corners of the tip of the support are chamfered is not limited to the example shown in FIG. 11.

Figure 12 is a schematic cross-sectional view showing another example of the internal structure of a heat diffusion device according to embodiment 6 of the present invention.

In the vapor chamber 1F' shown in Figure 12, the tip of the support 40d is flat.

In the example shown in FIG. 12, the corners at the tips of the pillars 40d have a C-chamfered shape.

The effect of the support 40d in the vapor chamber 1F' and the configuration when multiple support columns 40d are provided are the same as those in the vapor chamber 1F described above.

In the heat diffusion device of embodiment 6 of the present invention, when the corners of the tips of the supports have a chamfered shape, the chamfered shape is not limited to the examples shown in Figures 11 and 12, and may be other shapes.

<Embodiment 7>
In the heat diffusion device of the seventh embodiment of the present invention, the support pillar is longer in the expansion and contraction direction of the bellows structure among the planar directions perpendicular to the thickness direction than in the direction perpendicular to the expansion and contraction direction of the bellows structure. The heat diffusion device of the seventh embodiment of the present invention is similar to the heat diffusion devices of the first to sixth embodiments of the present invention except for the above points.

Figure 13 is a schematic plan view showing an example of a portion of the arrangement area of the wick and support pillars constituting the heat diffusion device of embodiment 7 of the present invention, as viewed from the thickness direction.

As shown in FIG. 13, the support 40e has a rectangular planar shape when viewed from the thickness direction T, and is longer in the direction of expansion and contraction of the bellows structure (length direction L in FIG. 13) than in the direction perpendicular to the expansion and contraction direction of the bellows structure (width direction W in FIG. 13).

Figure 14 is a schematic plan view showing another example of a portion of the arrangement area of the wick and support pillars constituting the heat diffusion device of embodiment 7 of the present invention, as viewed from the thickness direction.

As shown in FIG. 14, the support 40f has an elliptical planar shape when viewed from the thickness direction T, and is longer in the direction of expansion and contraction of the bellows structure (length direction L in FIG. 14) than in the direction perpendicular to the expansion and contraction direction of the bellows structure (width direction W in FIG. 14).

Figure 15 is a schematic plan view showing yet another example of a portion of the arrangement area of the wick and support pillars constituting the heat diffusion device of embodiment 7 of the present invention, viewed from the thickness direction.

As shown in FIG. 15, the support 40g has an elliptical planar shape when viewed from the thickness direction T, and is longer in the direction of expansion and contraction of the bellows structure (length direction L in FIG. 15) than in the direction perpendicular to the expansion and contraction direction of the bellows structure (width direction W in FIG. 15).

In a vapor chamber having the configuration shown in FIG. 13, FIG. 14, or FIG. 15, when the bellows structure of the bellows surface (for example, bellows surface 15a in FIG. 2) expands or contracts, the positional relationship between the support (support 40e, support 40f, or support 40g) and the bellows surface changes. In a vapor chamber having the configuration shown in FIG. 13, FIG. 14, or FIG. 15, the support is longer in the expansion and contraction direction of the bellows structure (here, length direction L) than in the direction perpendicular to the expansion and contraction direction of the bellows structure (here, width direction W). This makes it easier for the support to remain in contact with the bellows surface even if the positional relationship between the support and the bellows surface changes, and as a result, the housing 10 is stably supported by the support from the internal space side.

The planar shape of the support that is longer in the direction of expansion and contraction of the bellows structure than the direction perpendicular to the direction of expansion and contraction of the bellows structure is not limited to the rectangular, elliptical, and oval shapes described above, and may be other shapes.

In this embodiment, when multiple pillars are provided as shown in Figures 13, 14, and 15, at least one of the multiple pillars may be longer in the expansion and contraction direction of the bellows structure in the surface direction than in the direction perpendicular to the expansion and contraction direction of the bellows structure. In other words, in this embodiment, all of the multiple pillars may be longer in the expansion and contraction direction of the bellows structure in the surface direction than in the direction perpendicular to the expansion and contraction direction of the bellows structure, or some of the pillars may be longer in the expansion and contraction direction of the bellows structure in the surface direction than in the direction perpendicular to the expansion and contraction direction of the bellows structure.

[Electronic equipment]
The electronic device of the present invention is characterized by comprising the heat spreading device of the present invention.

Below, an electronic device having a heat diffusion device according to embodiment 1 of the present invention will be described as an example of an electronic device according to the present invention. The same applies to electronic devices having heat diffusion devices according to other embodiments of the present invention.

Figure 16 is a schematic perspective view showing an example of an electronic device of the present invention.

The electronic device 100 shown in FIG. 16 has a vapor chamber 1A.

In the example shown in FIG. 16, the vapor chamber 1A is bent using the bellows structure of the housing 10.

As shown in FIG. 16, it is preferable that the electronic device 100 further includes an electronic component 110.

As shown in FIG. 16, the electronic component 110 is preferably provided on the outer surface of the housing 10 of the vapor chamber 1A. In this case, the electronic component 110 can function as the heat source HS shown in FIG. 1, and the vapor chamber 1A can function.

The electronic component 110 is preferably not provided on the outer surface opposite the first inner surface 10a of the housing 10 of the vapor chamber 1A shown in FIG. 2, i.e., the outer surface opposite the inner surface of the first sheet 11 having the bellows structure, but is preferably provided on the outer surface opposite the second inner surface 10b, i.e., the outer surface opposite the inner surface of the second sheet 12.

The electronic components 110 may be provided directly on the outer surface of the housing 10, or may be provided via other members such as highly thermally conductive adhesives, sheets, or tapes.

It is preferable that the electronic component 110 overlaps the evaporation portion when mounted on the outer surface of the housing 10.

Examples of electronic components 110 include heat generating elements such as central processing units (CPUs), light emitting diodes (LEDs), and power semiconductors.

As shown in FIG. 16, it is preferable that the electronic device 100 further includes a device housing 120.

In the example shown in FIG. 16, the vapor chamber 1A and the electronic component 110 are provided in the internal space of the device housing 120.

In the example shown in FIG. 16, the device housing 120 is also bent, similar to the vapor chamber 1A.

In the electronic device 100, even if the device housing 120 is folded, the vapor chamber 1A can be configured to be provided in the internal space of the device housing 120 in a folded state in the same manner as the device housing 120, utilizing the bellows structure of the housing 10.

It is preferable that the housing 10 and the device housing 120 are joined via a joining member. More specifically, it is preferable that the outer surface of the housing 10 and the inner surface of the device housing 120 are joined via a joining member. In this case, the adhesion between the housing 10 and the device housing 120 is improved.

The joining member joining the housing 10 and the device housing 120 is preferably a thermally conductive member. In this case, heat from the heat source HS, in this case, heat from the electronic component 110, is easily conducted from the housing 10 to the device housing 120. In other words, the path from the housing 10 to the device housing 120 also makes it easier for heat from the heat source HS, in this case, heat from the electronic component 110, to diffuse.

Examples of thermally conductive members include thermally conductive tape and thermally conductive adhesives.

As described above, the vapor chamber 1A operates autonomously without requiring an external power source, and furthermore, by utilizing the latent heat of evaporation and latent heat of condensation of the working medium 20, the heat from the heat source HS, in this case the heat from the electronic component 110, can be diffused two-dimensionally at high speed. As a result, the electronic device 100 having the vapor chamber 1A can effectively dissipate heat in the limited space inside the electronic device 100.

This specification discloses the following:

＜1＞
a housing having a first inner surface and a second inner surface opposed to each other in a thickness direction and having an internal space;
A working medium sealed in the internal space of the housing; and
a wick disposed in the internal space of the housing at a position spaced from the first inner surface;
A support is provided on the second inner surface and penetrates the wick in the thickness direction to reach the first inner surface,
The first inner surface includes a bellows surface having a bellows structure,
A heat spreading device, wherein the support pillar is in contact with the bellows surface and is not fixed to the bellows surface.

＜2＞
The heat spreading device according to <1>, wherein the bellows surface includes a protrusion having a tip that contacts the support in the thickness direction.

＜3＞
The heat spreading device according to <1> or <2>, wherein the bellows surface includes a convex portion having a flat tip.

＜4＞
The heat diffusion device according to any one of <1> to <3>, wherein a gap is provided between the wick and the support in a plane direction perpendicular to the thickness direction.

＜5＞
The heat diffusion device according to <4>, wherein, when viewed from the thickness direction, the gaps are provided with unequal sizes around the support so that the gaps are longer in the expansion and contraction direction of the bellows structure among the surface directions than in a direction perpendicular to the expansion and contraction direction of the bellows structure.

＜6＞
The heat spreading device according to any one of <1> to <5>, wherein the tip of the support is rounded.

＜７＞
The heat spreading device according to any one of <1> to <5>, wherein the tip of the support is flat.

＜8＞
The heat spreading device according to <7>, wherein the corners of the tips of the posts are chamfered.

＜9＞
The heat diffusion device according to any one of <1> to <8>, wherein the support is longer in a direction perpendicular to the thickness direction in a direction of expansion and contraction of the bellows structure than in a direction perpendicular to the direction of expansion and contraction of the bellows structure.

＜10＞
An electronic device comprising the heat spreading device according to any one of <1> to <9>.

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. The heat diffusion device of the present invention can be used, for example, to lower the temperature of a heat source such as a central processing unit, thereby extending the operating time of electronic devices, and can be used in electronic devices such as smartphones, tablet terminals, laptops, game consoles, and wearable devices. In particular, the heat diffusion device of the present invention can be easily folded due to the bellows structure of the housing, and therefore can be mounted on the hinge portion of electronic devices that require folding, such as foldable smartphones and laptops.

1A, 1B, 1C, 1C', 1D, 1E, 1F, 1F' Vapor chamber (thermal diffusion device)
10 Housing 10a First inner surface 10b Second inner surface 11 First sheet 12 Second sheet 15a, 15b, 15c Bellows surface 16a, 16b, 16c Convex portion 17a, 17b, 17c Concave portion 20 Working medium 30 Wick 40a, 40b, 40c, 40d, 40e, 40f, 40g Support 50 Gap 100 Electronic device 110 Electronic component 120 Device housing HS Heat source L Length direction T Thickness direction W Width direction

Claims (10)

a housing having a first inner surface and a second inner surface opposed to each other in a thickness direction and having an internal space;
A working medium sealed in the internal space of the housing; and
a wick disposed in the internal space of the housing at a position spaced from the first inner surface;
A support is provided on the second inner surface and penetrates the wick in the thickness direction to reach the first inner surface,
The first inner surface includes a bellows surface having a bellows structure,
A heat spreading device, wherein the support pillar is in contact with the bellows surface and is not fixed to the bellows surface. The heat diffusion device according to claim 1, wherein the bellows surface includes a protrusion whose tip contacts the support in the thickness direction. The heat spreading device of claim 1, wherein the bellows surface includes a convex portion having a flat tip. The heat spreading device according to claim 1, wherein a gap is provided between the wick and the support in a plane direction perpendicular to the thickness direction. The heat diffusion device according to claim 4, wherein, when viewed from the thickness direction, the gaps are provided with unequal sizes around the support so that, in the planar direction, the gaps are longer in the direction of expansion and contraction of the bellows structure than in the direction perpendicular to the direction of expansion and contraction of the bellows structure. The heat spreading device of claim 1, wherein the tips of the posts are rounded. The heat spreading device of claim 1, wherein the tip of the support is flat. The heat spreading device according to claim 7, wherein the corners of the tips of the posts have a chamfered shape. The heat diffusion device of claim 1, wherein the support is longer in the expansion and contraction direction of the bellows structure in a planar direction perpendicular to the thickness direction than in a direction perpendicular to the expansion and contraction direction of the bellows structure. An electronic device comprising a heat diffusion device according to any one of claims 1 to 9.