JP2021156517A - Heat dissipating structure and electronic device - Google Patents

Abstract

To provide a heat dissipating structure that can efficiently dissipate heat from a heat source even if the heat source is arranged in a concave part.SOLUTION: A heat dissipating structure 101 comprises: a vapor chamber 102 including a tabular first case 110 comprising a first surface 111 and a second surface 112 opposed to each other in a thickness direction (a), and internally comprising a first internal space 113, first working liquid 120 enclosed in the first internal space 113, and a wick 130 arranged in the first internal space 113; and a gas-liquid exchange type thermally conductive body 103 including a second case 140 internally comprising a second internal space 143, and second working liquid 150 enclosed in the second internal space 143. The thermally conductive body 103 is joined to the first surface 111 of the vapor chamber 102. The area of the second surface 112 of the vapor chamber 102 is larger than the area of a portion joined to the thermally conductive body 103 out of the area of the first surface 111 of the vapor chamber 102.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat dissipation structure. The present invention also relates to an electronic device provided with the heat dissipation structure.

In recent years, the amount of heat generated has increased due to the high integration and high performance of devices. In addition, as the miniaturization of products progresses, the heat generation density increases, so heat dissipation measures have become important. This situation is particularly noticeable in the field of mobile terminals such as smartphones and tablets. In recent years, a graphite sheet or the like is often used as a heat countermeasure member, but since the heat transport amount thereof is not sufficient, the use of various heat countermeasure members has been studied. In particular, the use of a vapor chamber, which is a planar heat pipe, is being studied because it can diffuse heat very effectively.

The vapor chamber is a flat plate-shaped airtight container in which an appropriate amount of hydraulic fluid that easily volatilizes is sealed. The working liquid is vaporized by the heat from the heat source, moves in the internal space, and then releases heat to the outside to return to the liquid. The hydraulic fluid that has returned to liquid is carried to the vicinity of the heat source again by a capillary structure called a wick, and vaporizes again. By repeating this, the vapor chamber operates independently without having external power, and can diffuse heat two-dimensionally at high speed by utilizing the latent heat of vaporization and the latent heat of condensation of the working liquid.

Patent Document 1 describes a heat pipe having a condensing part where the working liquid condenses and an evaporating part where the working liquid evaporates. In Patent Document 1, a hydraulic fluid is sealed inside a heat pipe container, and a wick structure having a nanometer-order uneven structure is formed on both the inner wall of the lower container and the inner wall of the upper container. With such a configuration, two-dimensional heat diffusion is achieved.

Japanese Unexamined Patent Publication No. 2012-057841

The inside of an electronic device usually has a large number of irregularities. If the heat source is arranged in the recess and the flat housing constituting the vapor chamber is too large to be accommodated in the recess, the vapor chamber cannot be brought into contact with the heat source and a space is created between the heat source and the vapor chamber. The heat dissipation efficiency is reduced.
Therefore, a method has been performed in which such a space is filled with a heat transfer material such as a heat conductive grease or a copper plate, and heat is transferred from a heat source to a vapor chamber via the heat transfer material.

However, it cannot be said that the heat dissipation efficiency is sufficiently high by either method, and there is room for improvement in improving the heat dissipation efficiency.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a heat radiating structure capable of efficiently radiating heat from a heat source even if the heat source is arranged in a recess. That is.

The heat radiating structure of the present invention is enclosed in a flat plate-shaped first housing having a first surface and a second surface facing each other in the thickness direction and having a first internal space inside, and the first internal space. A first working fluid, a vapor chamber including a wick arranged in the first internal space, a second housing having a second internal space inside, and a second working fluid sealed in the second internal space. It is provided with a gas-liquid exchange type heat conductor including, and the heat conductor is joined to the first surface of the vapor chamber, and the area of the second surface of the vapor chamber is the vapor chamber. Of the area of the first surface of the above, it is characterized in that it is larger than the area of the portion bonded to the heat conductor.

The electronic device of the present invention is characterized by comprising the heat radiating structure of the present invention.

The heat dissipation structure of the present invention can efficiently dissipate heat from the heat source even if the heat source is arranged in the recess.

FIG. 1 is a cross-sectional view schematically showing an example of a heat radiating structure according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a usage example of the heat radiating structure according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing an example of a heat radiating structure according to a second embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing a usage example of the heat radiating structure according to the second embodiment of the present invention. FIG. 5 is a cross-sectional view schematically showing an example of a heat radiating structure according to a third embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing an example of a heat radiating structure according to a fourth embodiment of the present invention.

Hereinafter, the heat dissipation structure of the present invention will be described.
However, the present invention is not limited to the following configurations, and can be appropriately modified and applied without changing the gist of the present invention. It should be noted that a combination of two or more individual desirable configurations of the present invention described below is also the present invention.

It goes without saying that each of the embodiments shown below is an example, and partial replacement or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, the description of the matters common to the first embodiment will be omitted, and only the differences will be described. In particular, the same action and effect due to the same configuration will not be mentioned sequentially for each embodiment.

In the following description, when each embodiment is not particularly distinguished, it is simply referred to as "heat dissipation structure of the present invention".

[First Embodiment]
FIG. 1 is a cross-sectional view schematically showing an example of a heat radiating structure according to the first embodiment of the present invention.
The heat radiating structure 101 shown in FIG. 1 includes a vapor chamber 102 and a gas-liquid exchange type heat conductor 103.

The vapor chamber 102 has a first surface 111 and a second surface 112 facing in a thickness direction (direction indicated by an arrow a in FIG. 1), and a flat plate-shaped first housing having a first internal space 113 inside. The body 110, the first hydraulic fluid 120 enclosed in the first internal space 113, and the wick 130 arranged in the first internal space 113 are included.
The vapor chamber 102 includes, for example, a first sheet 111a forming the first surface 111 and a second sheet 112a forming the second surface 112. In the first internal space 113, a support column 114 that supports the first sheet 111a and the second sheet 112a may be arranged.

The heat conductor 103 includes a second housing 140 having a second internal space 143 inside, and a second working liquid 150 enclosed in the second internal space 143.
Further, in the heat radiating structure 101 shown in FIG. 1, the second housing 140 of the heat conductor 103 is a columnar shape having a third surface 141 and a fourth surface 142 facing each other in the thickness direction a, and is heat conductive. The third surface 141 of the body 103 is joined to the first surface 111 of the vapor chamber 102.

In the heat dissipation structure 101 shown in FIG. 1, the area of the second surface 112 of the vapor chamber 102 is larger than the area of the portion of the area of the first surface 111 of the vapor chamber 102 that is joined to the heat conductor 103. .. In FIG. 1, since the third surface 141 of the heat conductor 103 is joined to the first surface 111 of the vapor chamber 102, the area of the second surface 112 of the vapor chamber 102 is the third surface of the heat conductor 103. It is larger than the area of 141.

The principle of heat dissipation when using the heat dissipation structure 101 will be described.
FIG. 2 is a cross-sectional view schematically showing a usage example of the heat radiating structure according to the first embodiment of the present invention.
As shown in FIG. 2, when the heat radiating structure 101 is used, the heat source S is brought into contact with the fourth surface 142 of the heat conductor 103.
In FIG. 2, the heat source S is located on the lower side in the vertical direction. That is, in FIG. 2, the heat radiating structure 101 is arranged so that the heat source S, the heat conductor 103, and the vapor chamber 102 are arranged in this order from the lower side in the vertical direction to the upper side.
As shown in FIG. 2, when the fourth surface 142 of the heat conductor 103 receives heat from the heat source S, the second working liquid 150 in the second internal space 143 is vaporized by the heat from the heat source S. In FIG. 2, the moving direction of the vaporized second working liquid 150 is indicated by an arrow G. The vaporized second working liquid 150 reaches the upper part of the second internal space 143, releases heat, and returns to the liquid. In the heat conductor 103, the second working liquid 150 returns to the liquid and then moves to the lower part of the second space 143 by gravity.

The released heat reaches the first surface 111 of the vapor chamber 102 via the third surface 141 of the heat conductor 103. Then, the heat is released to the outside by the heat dissipation action of the vapor chamber 102. At this time, heat is mainly released from the second surface 112 of the vapor chamber 102.
As described above, in the heat radiating structure 101, the area of the second surface 112 of the vapor chamber 102 is larger than the area of the portion of the area of the first surface 111 of the vapor chamber 102 that is joined to the heat conductor 103. .. That is, the area of the second surface 112 of the vapor chamber 102 is larger than the area of the third surface 141 of the heat conductor 103. Therefore, the area of the surface on which heat is released can be made larger than the area of the surface on which heat is transferred from the heat conductor 103 to the vapor chamber 102. With such a structure, the heat that has reached the vapor chamber 102 is quickly released to the outside, so that the heat dissipation efficiency is high.

Therefore, even when the heat source S is arranged in the recess C having an entrance so narrow that the vapor chamber 102 cannot be accommodated, by arranging the heat conductor 103 in the recess C, the heat source passes through the heat conductor 103. Heat can be efficiently transferred from S to the vapor chamber 102. As a result, heat dissipation efficiency is improved.

The shapes of the first surface 111 and the second surface 112 of the vapor chamber 102 may be a flat surface, a curved surface, or a composite surface of a flat surface and a curved surface, respectively. Therefore, the shape of the first surface 111 of the vapor chamber 102 at the portion joined to the heat conductor 103 may be a flat surface, a curved surface, or a composite surface of a flat surface and a curved surface. ..
The area of the second surface 112 of the vapor chamber 102 means the surface area of the second surface 112 that can be seen when the vapor chamber 102 is viewed in a plan view from the second surface 112 side in the thickness direction a. For example, when the second surface 112 includes a slope, a curved surface, or the like, the area thereof is also included in the area of the second surface 112.
Further, when the first surface 111 has a slope or a curved surface and is joined to the heat conductor 103 at that portion, the area thereof is also joined to the heat conductor 103 out of the area of the first surface 111. Included in the area of the part

In the heat radiating structure 101, the area S1 of the portion of the area 111 of the first surface 111 of the vapor chamber 102 that is joined to the heat conductor 103 ^{is preferably 100 mm 2} or more and 400 mm ² or less.
In the heat radiating structure 101, the area S2 of the second surface 112 of the vapor chamber 102 ^{is preferably 800 mm 2} or more and 7200 mm ² or less.
From the viewpoint of improving heat dissipation efficiency, the ratio of the area S1 to the area S2 is preferably S2 / S1 = 4 or more and 24 or less.

In the heat radiating structure 101, it is preferable that the heat conductor 103 is within the contour of the vapor chamber 102 when viewed in a plan view from the thickness direction a of the vapor chamber 102.
With such a structure, heat is likely to be transferred linearly in the order of the heat source S, the heat conductor 103, and the vapor chamber 102, and the heat transfer distance is shortened. As a result, heat dissipation efficiency is improved.

In the heat radiating structure 101, the thickness of the side wall of the second housing 140 extending in the thickness direction a of the vapor chamber 102 is constant. Therefore, the area of the cross section of the second internal space 143 in the plane direction perpendicular to the thickness direction a of the vapor chamber 102 (the direction indicated by the arrow b in FIG. 1) is constant.

In the plane direction b of the vapor chamber 102, the area of the cross section of the second internal space 143 of the thermal conductor 103 is preferably smaller than the area of the cross section of the first internal space 113 of the vapor chamber 102. Further, when viewed in a plan view from the thickness direction a of the vapor chamber 102, it is preferable that the second internal space 143 of the heat conductor 103 overlaps with the first internal space 113 of the vapor chamber 102.
With such a structure, the heat transmitted through the internal space 143 of the heat conductor 103 is easily transferred to the first internal space 113 via the first surface 111 of the vapor chamber 102. As a result, heat dissipation efficiency is improved.

As shown in FIG. 1, in the heat radiating structure 101, in the thickness direction a of _{the vapor chamber 102, the height H 1} of the second housing 140 of the heat conductor 103 is the height H 1 of the first housing 110 of the vapor chamber 102. It is preferably higher than the height H _2.
Further, as shown in FIG. 1, in the thickness direction a, in the heat radiation structure 101, the height H ₃ of the second internal space 143 of the heat conductor 103 is the height of the first internal space 113 of the vapor chamber 102. preferably higher than H _4.
With such a structure, even if the recess C is deep and the distance from the heat source S arranged in the deep part of the recess C to the first surface 111 of the vapor chamber 102 is long, the heat source is passed through the heat conductor 103. Heat can be efficiently transferred from S to the vapor chamber 102.

In the heat radiating structure 101, the height H ₁ of the second housing 140 of the heat conductor 103 is preferably 1 mm or more and 5 mm or less in the thickness direction a of the vapor chamber 102.
In the heat radiating structure 101, the height H ₂ of the first housing 110 of the vapor chamber 102 is preferably 0.1 mm or more and 0.5 mm or less in the thickness direction a of the vapor chamber 102.

Next, preferable materials, structures, and the like of each configuration of the heat radiating structure 101 will be described.

The material of the first housing 110 constituting the vapor chamber 102 is not particularly limited as long as it has characteristics suitable for use as a housing of the vapor chamber, such as thermal conductivity, strength, and flexibility. The material constituting the first housing 110 is preferably a metal, and examples thereof include copper, nickel, aluminum, magnesium, titanium, iron, and the like, or alloys containing them as main components.

When the first housing 110 is composed of the first sheet 111a and the second sheet 112a, the material constituting the first sheet 111a and the material constituting the second sheet 112a may be different. For example, by using a high-strength material for the first sheet 111a, the stress applied to the first housing 110 can be dispersed. Further, by using different materials, one sheet can obtain one function and the other sheet can obtain another function. The above functions are not particularly limited, and examples thereof include a heat conduction function and an electromagnetic wave shielding function.

The thickness of the first sheet 111a and the second sheet 112a is not particularly limited, but if the first sheet 111a and the second sheet 112a are too thin, the strength of the first housing 110 is lowered and deformation is likely to occur. Therefore, the thickness of the first sheet 111a and the second sheet 112a is preferably 20 μm or more, and more preferably 30 μm or more, respectively. On the other hand, if the first sheet 111a and the second sheet 112a are too thick, it becomes difficult to reduce the thickness of the vapor chamber 102. Therefore, the thickness of the first sheet 111a and the second sheet 112a is preferably 200 μm or less, more preferably 150 μm or less, and further preferably 100 μm or less. The thicknesses of the first sheet 111a and the second sheet 112a may be the same or different.

The thickness of the first sheet 111a of the vapor chamber 102 may be constant, or may have a thick portion and a thin portion. Similarly, the thickness of the second sheet 112a of the vapor chamber 102 may be constant, or a thick portion and a thin portion may be present.

When the vapor chamber 102 includes the support column 114, the material of the support column 114 is not particularly limited, but copper, a copper alloy, or the like is preferable.
The shape of the support column 114 is not particularly limited as long as it can support the first sheet 111a and the second sheet 112a and form the first internal space 113, and is, for example, a cylindrical shape, a prismatic shape, a truncated cone shape, or a pyramid. Examples include trapezoidal shapes.

When manufacturing the vapor chamber 102, the wick 130 is arranged on the inner wall surface of the first sheet 111a, and these are overlapped so that the inner wall surface of the first sheet 111a and the inner wall surface of the second sheet 112a face each other. The sheet 111a and the second sheet 112a are joined at the outer edge. At this time, an encapsulation port for encapsulating the first working liquid 120 is formed.
After that, the vapor chamber 102 can be manufactured by putting the first working liquid 120 through the sealing port and closing the sealing port.

The bonding method of the first sheet 111a and the second sheet 112a is not particularly limited, but laser welding, resistance welding, diffusion welding, brazing, TIG welding (tungsten-inert gas welding), ultrasonic bonding, resin sealing, etc. Can be mentioned. Of these, laser welding, resistance welding or brazing is preferred.

The first working liquid 120 of the vapor chamber 102 is not particularly limited as long as it can cause a gas-liquid phase change in the environment inside the first housing 110, and for example, water, alcohols, CFC substitutes, or the like can be used. Can be used. The first working liquid 120 is preferably an aqueous compound, more preferably water.

In the heat radiating structure 101, the wick 130 of the vapor chamber 102 may have any structure as long as it has a capillary structure capable of moving the first working liquid 120 of the liquid by a capillary phenomenon. Examples of the capillary structure include fine structures having irregularities such as pores, grooves, and protrusions, such as a porous structure, a fiber structure, a groove structure, and a mesh structure.

The material of the wick 130 is not particularly limited, and may be, for example, a metal porous film formed by etching or metal processing, a mesh, a non-woven fabric, a sintered body, a porous body, or the like. The mesh used as the material of the wick 130 may be, for example, a metal mesh, a resin mesh, or a surface-coated mesh thereof, and is preferably composed of a copper mesh, a stainless steel (SUS) mesh, or a polyester mesh. NS. The sintered body used as the material of the wick 130 may be composed of, for example, a metal porous sintered body and a ceramic porous sintered body, and is preferably composed of a copper or nickel porous sintered body. NS. The porous body used as the material of the wick 130 may be, for example, a porous body composed of a metal porous body, a ceramic porous body, a resin porous body, or the like.
Among these, a stainless steel (SUS) mesh having high heat resistance and being plastically deformable is preferable.

The material constituting the second housing 140 of the thermal conductor 103 is preferably a metal, and examples thereof include copper, nickel, aluminum, magnesium, titanium, iron, and the like, or alloys containing them as main components. ..

The shape of the second housing 140 of the heat conductor 103 is any shape as long as the fourth surface 142 can come into contact with the heat source S and heat can be transferred from the heat source S to the first surface 111 of the vapor chamber 102. It may be preferable, and it is preferable to appropriately select it according to the shape of the recess C. For example, the second housing 140 of the heat conductor 103 may have a columnar shape such as a columnar shape, an elliptical columnar shape, an oblong columnar shape, a triangular columnar shape, or a square columnar shape. Further, when the concave portion C has a deformed shape, it may have a shape that just fits in the concave portion C.

When manufacturing the thermal conductor 103, a member to be the third surface 141 is arranged at one end of the tubular member, and a member to be the fourth surface 142 is arranged at the other end of the tubular member to join them.
At this time, an encapsulation port for encapsulating the second hydraulic fluid 150 is formed.
After that, the heat conductor 103 can be manufactured by pouring the second working liquid 150 through the sealing port and closing the sealing port.

The joining method of the tubular member, the member to be the third surface 141, and the member to be the fourth surface 142 is not particularly limited, but is limited to laser welding, resistance welding, diffusion welding, brazing, and TIG welding (tungsten-inert gas welding). ), Ultrasonic welding, resin sealing, etc. Of these, laser welding, resistance welding or brazing is preferred.

The second working liquid 150 of the heat conductor 103 is not particularly limited as long as it can cause a gas-liquid phase change in the environment inside the second housing 140, and is, for example, water, alcohols, CFC substitutes, or the like. Can be used. The second working liquid 150 is preferably an aqueous compound, more preferably water.

In the heat radiating structure 101, the third surface 141 of the heat conductor 103 is joined to the first surface 111 of the vapor chamber 102, but the joining method is not particularly limited, and soldering, brazing, and welding are performed. It may be joined by.

The heat source S shown in FIG. 2 is not particularly limited as long as it is a heating element, and examples thereof include a processor, a light emitting element, and a power source.

[Second Embodiment]
FIG. 3 is a cross-sectional view schematically showing an example of a heat radiating structure according to a second embodiment of the present invention.
FIG. 4 is a cross-sectional view schematically showing a usage example of the heat radiating structure according to the second embodiment of the present invention.

The heat radiation structure 201 shown in FIG. 3 is shown in FIG. 3 except that the heat conductor 103 includes a wick 260 arranged in the second internal space 143 and the wick 260 is arranged on the inner wall surface of the second housing 140. It has the same configuration as the heat dissipation structure 101 shown in 1.
Further, as shown in FIG. 4, when the heat radiating structure 201 is used, the heat source S is arranged on the upper side in the vertical direction, and the vapor chamber 102, the heat conductor 103, and the heat source S are arranged from the lower side in the vertical direction to the upper side. The heat dissipation structure 201 is arranged so that the heat dissipation structures 201 are arranged in order.

In the heat radiating structure 101 shown in FIG. 2 described above, the second working liquid 150 sealed in the second internal space 143 of the heat conductor 103 is vaporized by the heat source S located below the heat conductor 103 in the vertical direction. After carrying the heat, it releases the heat and returns to the liquid, and moves to the lower part of the second internal space 143 of the heat conductor 103 by gravity.
However, when the heat source S is located above the heat conductor 103 in the vertical direction, the second working liquid 150 of the liquid accumulates below due to gravity, so that the liquid cannot move to the vicinity of the heat source S and heat is transferred. I can't let you.
On the other hand, as shown in FIG. 4, when the heat conductor 103 includes the wick 260, the liquid second working liquid 150 can move to the vicinity of the heat source S due to the capillary phenomenon. Then, the second working liquid 150 is vaporized by the heat from the heat source S, moves in the second internal space 143, moves the heat to the vapor chamber 102, and returns to the liquid. Therefore, the second hydraulic fluid 150 can circulate in the second internal space 143.

Also, since the vapor chamber 102 is thin, most of the first hydraulic fluid 120 is held in the wick 130. That is, most of the first hydraulic fluid 120 is located on the first main surface 111 side of the vapor chamber 102.
Therefore, the first working liquid 120 easily receives the heat from the heat conductor 103, is vaporized by the heat, and quickly moves in the internal space 113 of the vapor chamber 102. Then, the heat is mainly dissipated from the second main surface 112 of the vapor chamber 102.
The vaporized first working liquid 120 releases heat and returns to the liquid, and moves in the wick 130 due to the capillary phenomenon to move to the first main surface 111 side of the vapor chamber 102. Therefore, the first working fluid 120 can circulate in the first internal space 113 of the vapor chamber 102.

According to such a principle, the heat radiating structure 201 can function even if the heat source S is arranged vertically above the heat conductor 103.

When the heat radiating structure 201 is used, the second working liquid 150 can be circulated by the wick 260, so that the position of the heat source S is not only the position above the heat conductor 103 in the vertical direction, but also what kind of position. It may be located in the direction.

The preferred configuration of the wick 260 of the thermal conductor 103 is the same as the preferred configuration of the wick 130 of the vapor chamber 102.
In the heat radiating structure 201, the material constituting the wick 260 may be the same as or different from the material constituting the wick 130.

As described above, in the heat radiating structure 201, heat can be radiated regardless of the arrangement position of the heat source S.
Therefore, the heat radiating structure 201 may be used in a state where the upper side of the device changes depending on the usage state and the upper side of the device and the upper side in the vertical direction do not match, such as smartphones, tablet terminals, and mobile game devices. It is also suitable for certain electronic devices.

[Third Embodiment]
FIG. 5 is a cross-sectional view schematically showing an example of a heat radiating structure according to a third embodiment of the present invention.
The heat radiating structure 301 shown in FIG. 5 has the same structure as the heat radiating structure 201 shown in FIG. 3, except that the second housing 340 of the heat conductor 103 has a plurality of second internal spaces 343.
With such a structure, the volume per second internal space 343 can be reduced, and the amount and arrangement area of the wick 260 per volume of the second internal space 343 can be increased. As the amount and placement area of the wick 260 increase, the moving speed of the second hydraulic fluid 150 of the liquid increases. Therefore, the second hydraulic fluid 150 is easily circulated, and there is no problem even if the heat generation amount of the heating element is large, and the heat dissipation mechanism by air-liquid exchange operates.

[Fourth Embodiment]
FIG. 6 is a cross-sectional view schematically showing an example of a heat radiating structure according to a fourth embodiment of the present invention.
The heat radiating structure 401 shown in FIG. 6 has a structure in which the second internal space 443 of the heat conductor 103 in the second housing 440 becomes narrower toward the vapor chamber 102 in the thickness direction a of the vapor chamber 102. Except for the above, the structure is the same as that of the heat radiating structure 201 shown in FIG.
As shown in FIG. 6, in the heat radiating structure 401, there is a portion where a part of the side wall surface 443s of the internal space 443 is not orthogonal to the horizontal plane but is oblique. In this part, the wick 260 will also be arranged diagonally.
With such a structure, the second hydraulic fluid 150 can easily move upward through the wick 260 arranged at an angle. Therefore, the second hydraulic fluid 150 is easily circulated, and there is no problem even if the heat generation amount of the heating element is large, and the heat dissipation mechanism by air-liquid exchange operates.

In the heat radiating structure 401, the shape of the internal space 443 is not particularly limited as long as it becomes narrower toward the vapor chamber 102. For example, it may have a shape such as a triangular pyramid, a quadrangular pyramid, or a cone having the upper surface as the bottom surface, and the narrowing ratio is not constant, and there is a part where the narrowing ratio is suddenly narrowed. Alternatively, the shape may be such that there is a portion that gradually narrows. Further, the shape may be narrowed toward the vapor chamber 102.

[Other Embodiments]
The heat radiating structure of the present invention is not limited to the above embodiment, and various applications and modifications can be applied within the scope of the present invention regarding the configuration of the vapor chamber and the heat conductor, the manufacturing conditions, and the like. Is.

In the heat dissipation structure of the present invention, a plurality of heat conductors may be bonded to the first surface of the vapor chamber.
With such a structure, heat generated from a plurality of heat sources can be dissipated by one vapor chamber.

In the heat radiating structure of the present invention, the shape of the first housing of the vapor chamber is not particularly limited. For example, the planar shape of the housing (the shape seen from the upper side of the drawing in FIG. 1) includes polygons such as triangles and rectangles, circles, ellipses, and combinations thereof.
It is preferable that the shape of the first housing of the vapor chamber is appropriately set according to the shape of the electronic device in which the heat radiating structure is arranged.

In the heat radiating structure 101, the columns 114 were arranged between the first sheet 111a and the second sheet 112a of the vapor chamber 102, but in the heat radiating structure of the present invention, the columns were not arranged in the vapor chamber. May be good.

In the heat radiating structure of the present invention, the shape of the heat conductor does not have to be columnar, and a part of the heat conductor may be curved in a curved shape.
Further, the shape of the heat conductor may be a shape deformed according to the shape of the concave portion of the electronic device to be arranged. For example, in FIG. 2, the shape of the space forming the recess C in which the heat radiating structure 101 is arranged has a constant cross-sectional shape in the surface direction b of the vapor chamber 102 from the bottom of the recess toward the opening of the recess. It had a certain shape. However, the recess in which the heat dissipation structure of the present invention is arranged has a shape in which the shape of the space forming the recess increases in the surface direction b of the vapor chamber from the bottom of the recess toward the opening of the recess. Alternatively, the shape may be such that the cross section of the vapor chamber in the surface direction b becomes smaller from the bottom of the recess toward the opening of the recess. When the recess has such a shape, the shape of the heat conductor may be a shape that just fits in the recess.

In the heat radiating structure of the present invention, the shape of the portion of the heat conductor that comes into contact with the heat source of the second housing is preferably a shape that exactly overlaps the contact surface on the heat source side.
With such a shape, heat can be transferred from the heat source to the vapor chamber without waste.

The heat dissipation structure of the present invention can be mounted on an electronic device for the purpose of heat dissipation. Therefore, the electronic device provided with the heat dissipation structure of the present invention is also one of the present inventions. Examples of the electronic device of the present invention include smartphones, tablet terminals, notebook computers, game devices, wearable devices, and the like. As described above, the heat radiating structure 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 the latent heat of condensation of the working liquid. Therefore, the electronic device provided with the vapor chamber or the heat dissipation device of the present invention can effectively realize heat dissipation in the limited space inside the electronic device.

In the electronic device of the present invention, the heat conductor and the heat source may be brought into direct contact with each other, or these may be adhered with a heat conductive resin.

101, 201, 301, 401 Heat dissipation structure 102 Vapor chamber 103 Thermal conductor 110 First housing 111 First surface 111a First sheet 112 Second surface 112a Second sheet 113 First internal space 114 Support column 120 First working fluid 130, 260 Wick 140, 340, 440 Second housing 141 Third surface 142 Fourth surface 143, 443 Second internal space 443s Side wall surface 150 Second working fluid a Vapor chamber thickness direction b Vapor chamber surface direction C Recess S heat source

Claims (10)

A flat plate-shaped first housing having a first surface and a second surface facing each other in the thickness direction and having a first internal space inside, a first hydraulic fluid sealed in the first internal space, and the above. A vapor chamber including a wick placed in the first interior space,
A gas-liquid exchange type heat conductor including a second housing having a second internal space inside and a second working liquid enclosed in the second internal space is provided.
The heat conductor is joined to the first surface of the vapor chamber.
A heat radiating structure characterized in that the area of the second surface of the vapor chamber is larger than the area of the portion of the area of the first surface of the vapor chamber that is joined to the heat conductor. The heat radiating structure according to claim 1, wherein the heat conductor is contained within the contour of the vapor chamber when viewed in a plan view from the thickness direction of the vapor chamber. The heat radiating structure according to claim 1 or 2, wherein the area of the cross section of the second internal space is smaller than the area of the cross section of the first internal space in the plane direction perpendicular to the thickness direction of the vapor chamber. The heat radiating structure according to any one of claims 1 to 3, wherein the height of the second housing is higher than the height of the first housing in the thickness direction of the vapor chamber. The heat radiating structure according to any one of claims 1 to 4, wherein the height of the second internal space is higher than the height of the first internal space in the thickness direction of the vapor chamber. The heat radiating structure according to any one of claims 1 to 5, wherein the heat conductor further includes a wick arranged in the second internal space. The heat radiating structure according to any one of claims 1 to 6, wherein the second housing has a plurality of the second internal spaces. The heat radiating structure according to any one of claims 1 to 7, wherein the second internal space becomes narrower toward the vapor chamber in the thickness direction of the vapor chamber. The heat radiating structure according to any one of claims 1 to 8, wherein a plurality of the heat conductors are bonded to the first surface of the vapor chamber. An electronic device comprising the heat radiating structure according to any one of claims 1 to 9.

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