JP2020038051A - Vapor chamber and electronic apparatus - Google Patents

Abstract

An object of the present invention is to provide a vapor chamber capable of increasing heat transfer ability even when a flow path has a direction changing.
A condensed liquid flow path, which is a flow path in which a working fluid moves in a condensed liquid state, and a flow path cross-sectional area larger than that of the condensed liquid flow path, and the working fluid is in a vapor and condensed liquid state. A plurality of condensate flow paths, a plurality of condensate flow paths, a plurality of condensate flow paths, and a plurality of condensate flow paths; And a curved section in which the direction in which the steam flow path extends changes. The steam flow path in the curved section is configured to have a larger flow path cross-sectional area than the steam flow path in the straight section.
[Selection diagram] FIG.

Description

  The present invention relates to a vapor chamber that performs heat transport while a working fluid enclosed in a closed space moves.

2. Description of the Related Art Electronic components such as personal computers and mobile terminals such as mobile phones and tablet terminals use electronic components such as a central processing unit (CPU). Since the amount of heat generated from such electronic components tends to increase due to the improvement in information processing capability, a technique for cooling the heat is important.
Heat pipes are well known as a means for cooling. In this method, the working fluid enclosed in the pipe uses the phase change to transport the heat in the heat source to another portion to diffuse the heat, thereby cooling the heat source.

  On the other hand, in recent years, the thickness of these electronic devices has been remarkably reduced, and a cooling means thinner than a conventional heat pipe has been required. On the other hand, a vapor chamber has been proposed. The vapor chamber is also called a sheet-type heat pipe, and is a device in which the concept of heat transport by the heat pipe is developed to a flat member. That is, in the vapor chamber, the working fluid is sealed between the opposed flat plates, and the heat in the heat source is transported and diffused by utilizing the phase change of the working fluid to cool the heat source.

  Such a vapor chamber is disposed inside the electronic device, and since many other members are disposed inside the electronic device, there are many restrictions on the position where the vapor chamber can be disposed. In this case, the flow path for the working fluid cannot always be provided in a straight line. For example, as described in Patent Literature 1, by providing a flow path having a curved portion so that the direction changes, the arrangement We had to deal with constraints.

JP-A-2006-205693

  However, as described in Patent Document 1, in a vapor chamber in which the direction of the flow path of the working fluid changes, there is a problem that it is difficult to increase the heat transport ability.

  In view of the above problems, it is an object of the present invention to provide a vapor chamber that can increase the heat transport ability even when having a channel that changes direction. Further, an electronic device including the vapor chamber is provided.

  As a result of intensive studies, the inventor has found that, in a vapor chamber having a plurality of steam flow paths whose directions change, the flow resistance of the working fluid increases when the direction of the flow path of the working fluid changes, and the end of the flow path reaches the end of the flow path. It has been found that steam is difficult to be transmitted and heat transfer may not be sufficiently performed. In addition, since the lengths of the plurality of steam flow paths are different, a difference in flow resistance is generated, so that the working fluid does not move in a well-balanced manner. It was also found that performance could not be achieved. The inventors have completed the present invention based on these findings. Hereinafter, the present invention will be described.

  One aspect of the present invention is a vapor chamber in which a working fluid is sealed in a closed space, wherein the closed space includes a condensed liquid passage, which is a passage through which the working fluid moves in a condensed liquid state, and a condensed liquid passage. A plurality of steam flow paths having a flow path cross-sectional area larger than the flow path and in which the working fluid moves in a state of steam and condensate are provided, and the plurality of condensate flow paths and the plurality of steam flow paths are linear. And a curved portion which is continuous with the straight portion and in which the direction in which the plurality of condensed liquid flow paths and the plurality of vapor flow paths extend is changed. This is a vapor chamber configured to have a flow path cross-sectional area larger than a flow path.

  The steam flow path in the curved portion of the vapor chamber may be configured such that a cross-sectional area of the flow path is constant in a direction in which the steam flow path extends.

  In the above vapor chamber, the steam flow path in the curved portion may be configured to be wider than the steam flow path in the straight portion.

  In the above-mentioned vapor chamber, a plurality of steam channels may be connected.

  In the above vapor chamber, the plurality of steam channels in the curved portion may be configured to have different widths.

  Further, another aspect of the present invention is a housing, an electronic component disposed inside the housing, and the above-described vapor chamber disposed in contact with the electronic component directly or via another member. An electronic device comprising:

  ADVANTAGE OF THE INVENTION According to this invention, even when a vapor chamber has the flow path which changes a direction, the heat transport ability can be improved.

FIG. 1A is a perspective view of the vapor chamber 1, and FIG. 1B is an exploded perspective view of the vapor chamber 1. FIG. 2 is a perspective view of the first sheet 10. FIG. 3 is a plan view of the first sheet 10. FIG. 4 is a cut surface of the first sheet 10. FIGS. 5A and 5B show other cut surfaces of the first sheet 10. FIG. 6 is an enlarged view of a part of the outer peripheral liquid flow path portion 14 in plan view. FIG. 7 is a partially enlarged view of another example of the outer peripheral liquid flow path portion 14 when viewed from above. FIG. 8A is a cross-sectional view focusing on the inner liquid flow path 15, and FIG. 8B is an enlarged view of a part of the inner liquid flow path 15 in plan view. FIGS. 9A to 9C are diagrams illustrating an example of the shape of the bending portion 18c. FIG. 10 is a diagram illustrating an example in which a pillar 16 a is provided in the steam flow channel 16. FIG. 11A is a plan view of the curved portion 18c, and FIG. 11B is a diagram illustrating the curved portion 18c in another example. FIG. 12 is a diagram illustrating a curved portion 18c according to another example. FIG. 13 is a perspective view of the second sheet 20. FIG. 14 is a plan view of the second sheet 20. FIG. 15 is a cut surface of the second sheet 20. FIG. 16 shows another cut surface of the second sheet 20. FIG. 17 shows a cut surface of the vapor chamber 1. FIG. 18 is an enlarged view of a part of FIG. FIG. 19 shows another cut surface of the vapor chamber 1. 20 (a) to 20 (c) are diagrams illustrating an example of the form of the condensate flow path. FIG. 21 is a diagram illustrating the condensate flow path 3 and the vapor flow path 4. FIG. 22 is a perspective view illustrating the electronic device 40. FIG. 23 is a view for explaining the operation of the vapor chamber 1. FIG. 24 is an external perspective view of the vapor chamber 201. FIG. 25 is an exploded perspective view of the vapor chamber 201. FIG. 26A is a diagram of the third sheet 230 viewed from one surface, and FIG. 26B is a diagram of the third sheet 230 viewed from the other surface. FIG. 27 shows a cut surface of the third sheet 230. FIG. 28 shows another cut surface of the third sheet 230. FIG. 29 shows a cut surface of the vapor chamber 201. FIG. 30 is an enlarged view of a part of FIG. FIG. 31 shows another cut surface of the vapor chamber 201.

  Hereinafter, each embodiment will be described with reference to the drawings. However, the present invention is not limited to these modes. In the drawings described below, the size and ratio of members may be changed or exaggerated for simplicity. In addition, for the sake of simplicity, parts that are not necessary for the description may be omitted from the drawings or symbols.

  FIG. 1A is an external perspective view of the vapor chamber 1 according to the first embodiment, and FIG. 1B is an exploded perspective view of the vapor chamber 1. Arrows (x, y, z) indicating directions orthogonal to each other are also shown in these drawings and each of the drawings described below for convenience as needed. Here, the direction in the xy plane is a direction along the plate surface of the vapor chamber 1 having a flat plate shape, and the z direction is a thickness direction.

  The vapor chamber 1 of the present embodiment has a first sheet 10 and a second sheet 20 as can be seen from FIGS. 1A and 1B. Then, as will be described later, the first sheet 10 and the second sheet 20 are overlapped and joined (diffusion bonding, brazing, etc.), so that the first sheet 10 and the second sheet 20 are separated from each other. A working fluid is sealed in the hollow portion to form a closed space 2 (see, for example, FIG. 17).

In the present embodiment, the first sheet 10 is a sheet-like member as a whole, and is L-shaped in plan view. FIG. 2 is a perspective view of the first sheet 10 viewed from the inner surface 10a side, and FIG. 3 is a plan view of the first sheet 10 viewed from the inner surface 10a side. FIG. 4 shows a cut surface of the first sheet 10 when cut along the line IV-IV in FIG.
The first sheet 10 includes an inner surface 10a, an outer surface 10b opposite to the inner surface 10a, and a side surface 10c that forms a thickness across the inner surface 10a and the outer surface 10b, and a flow in which the working fluid moves to the inner surface 10a side. A pattern for the road is formed. As described below, a hollow portion is formed by overlapping the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20 so as to face each other. Become.

  The thickness of the first sheet 10 is not particularly limited, but is preferably 0.01 mm or more and 1.0 mm or less, and more preferably 0.05 mm or more and 0.2 mm or less. This can increase the number of scenes that can be applied as a thin vapor chamber.

The first sheet 10 has a main body 11 and an injection section 12. The main body 11 has a sheet-like shape forming a portion where the working fluid moves, and in this embodiment, is an L-shape having a portion that is curved in a plan view.
The injection part 12 is a part for injecting a working fluid into a hollow part formed by the first sheet 10 and the second sheet 20, and in this embodiment, is a square sheet in a plan view projecting from an L-shape in a plan view of the main body 11. It is. In this embodiment, the injection portion 12 of the first sheet 10 has a flat surface on both the inner surface 10a and the outer surface 10b.

On the inner surface 10a side of the main body 11, a structure for moving the working fluid is formed.
Specifically, as the structure, on the inner surface 10a side of the main body 11, an outer peripheral joint portion 13, an outer peripheral liquid passage portion 14, an inner liquid passage portion 15, a steam passage groove 16, and a steam passage communication groove 17 are provided. Provided.

The outer peripheral joint portion 13 is a surface formed on the inner surface 10 a side of the main body 11 along the outer periphery of the main body 11. The outer peripheral joint 13 overlaps the outer peripheral joint 23 of the second sheet 20 and is joined (diffusion joined, brazed, or the like), so that a hollow portion is formed between the first sheet 10 and the second sheet 20. The sealed space 2 is formed by enclosing the working fluid therein.
3, the width of the outer peripheral joint 13 shown in _{A 10} in FIG. 4 can be set appropriately as necessary, is preferably 0.05mm or more 5.0mm or less at the smallest. If this width is smaller than 0.05 mm, there is a possibility that the joining area becomes insufficient when a positional shift occurs during joining of the first sheet and the second sheet. On the other hand, if the width is larger than 5.0 mm, the internal volume of the closed space becomes small, and there is a possibility that the steam flow path and the condensate flow path cannot be sufficiently secured.

  The outer peripheral liquid flow path portion 14 functions as a liquid flow path portion and is a portion that constitutes a part of the condensed liquid flow path 3 (for example, see FIG. 18) that is a flow path that passes when the working fluid is condensed and liquefied. is there. FIG. 5 (a) shows a portion indicated by an arrow Va in FIG. 4, and FIG. 5 (b) shows a cut surface along Vb-Vb in FIG. In each of the figures, the cross-sectional shape of the outer peripheral liquid flow path portion 14 appears. FIG. 6 is an enlarged view of the outer peripheral liquid flow path portion 14 as viewed in the direction indicated by the arrow VI in FIG.

As can be seen from these figures, the outer peripheral liquid flow path portion 14 is formed along the inner surface of the outer peripheral joint portion 13 of the inner surface 10 a of the main body 11, and provided so as to be annular along the outer periphery of the closed space 2. I have. Further, the outer peripheral liquid flow path portion 14 is formed with a plurality of liquid flow groove grooves 14a extending in parallel to the direction in which the outer liquid flow path section 14 extends. The channels are arranged at intervals in a direction different from the direction in which the flow channel 14a extends. Therefore, as can be seen from FIGS. 5 (a) and 5 (b), in the outer peripheral liquid flow path section 14, the liquid flow path groove 14a which is a concave portion in the cross section and the wall 14b which is a convex portion between the liquid flow path grooves 14a are formed. Are formed by repeating irregularities.
Here, since the liquid channel groove 14a is a groove, the liquid channel groove 14a has a bottom in a cross-sectional shape thereof, and an opening at an opposite portion facing the bottom.

  By providing a plurality of liquid flow grooves 14a in this way, the depth and width of each liquid flow groove 14a are reduced, and the flow path cross-sectional area of the condensed liquid flow path 3 (for example, see FIG. 18) is reduced. It can be made smaller to take advantage of the larger capillary forces. On the other hand, by using a plurality of liquid flow grooves 14a, an appropriate internal volume of the condensed liquid flow path 3 as a whole is secured, and a required flow rate of the condensed liquid can be supplied.

  Further, in the outer peripheral liquid flow path portion 14, as can be seen from FIG. 6, the adjacent liquid flow path grooves 14a communicate with each other through communication openings 14c provided at intervals on the wall 14b. This promotes equalization of the amount of condensed liquid between the plurality of liquid flow grooves 14a, and allows the condensed liquid to flow efficiently. In addition, a communication opening 14 c provided in the wall 14 b adjacent to the steam flow channel groove 16 that forms the steam flow channel 4 connects the steam flow channel 4 and the condensate flow channel 3. Accordingly, by providing the communication opening 14c, the condensed liquid generated in the vapor flow path 4 can be smoothly moved to the condensed liquid flow path 3, and the vapor generated in the condensed liquid flow path 3 can be smoothly transferred to the vapor flow path. 4 can also be moved, which also facilitates smooth movement of the working fluid.

In the present embodiment, as shown in FIG. 6, the communication opening 14c is disposed so as to face the same position in the direction in which the liquid flow channel 14a extends across the one liquid flow channel 14a. However, the present invention is not limited to this. For example, as shown in FIG. 7, the communication openings 14c are arranged at different positions in the direction in which the liquid flow channel 14a extends across the one liquid flow channel 14a. May be done. That is, in this case, the communication opening 14c is arranged offset in the direction in which the liquid flow channel 14a extends.
By providing the communication opening 14c offset as described above, the communication opening 14c does not appear on both sides at the same time when viewed from the working fluid traveling through the condensate flow path 3, and the communication opening 14c appears. The wall 14b is always present on at least one side. Therefore, the capillary force can be continuously obtained. By forming the communication opening 14c offset from this viewpoint, the capillary force acting on the working fluid can be kept high, so that the condensate can flow smoothly.

It is preferable that the outer peripheral liquid flow path section 14 having the above configuration further has the following configuration.
3, 4, FIG. 5 (a), the the width of the outer fluid passage section 14 shown in B ₁₀ in FIG. 5 (b), can be appropriately set from the size of the entire vapor chamber, 0 It is preferably from 0.03 mm to 2 mm. If this width is smaller than 0.03 mm, there is a possibility that a sufficient amount of liquid flowing outside cannot be obtained. If the width exceeds 2 mm, there is a possibility that sufficient space for the inner condensate flow path or vapor flow path cannot be obtained.

For liquid flow path grooves 14a, FIG. 5 (a), the groove width shown in _{C 1} to 6 is preferably 10μm or more 300μm or less.
Further, it is preferable that the depth of the liquid flow channel 14a indicated by D in FIGS. 5A and 5B is not less than 5 μm and not more than 200 μm. Thereby, the capillary force of the liquid flow path necessary for the flow of the condensed liquid can be sufficiently exhibited. Here, it is preferable that the depth D of the liquid passage groove is smaller than the remaining sheet thickness obtained by subtracting the depth D of the groove from the thickness of the first sheet 10. This makes it possible to more reliably prevent the sheet from being broken when the working fluid is frozen.
From the viewpoint of exhibiting stronger capillary force of the channel, the aspect ratio of the represented flow path cross-section C ₁ in a value obtained by dividing the D (aspect ratio) is greater than 1.0, or 1.0 than Preferably, it is small. Among them, C ₁ is preferably larger than D from the viewpoint of ease of production, and the aspect ratio is preferably larger than 1.3.

Also, the walls 14b, FIG. 5 (a), the it is preferable that the width indicated by _{C 2} in FIG. 6 is 20μm or more 300μm or less. If the width is smaller than 20 μm, the working fluid tends to break due to repeated freezing and melting. There is a possibility that smooth communication of the fluid may be hindered.

For communication opening portion 14c, the magnitude of the liquid flow path groove 14a is communicated with the opening 14c along the extending direction indicated by _{C 3} 6 is preferably 20μm or more 180μm or less.
Further, it is preferable that the pitch of the communication opening portion 14c adjacent in the extending direction the liquid flow path groove 14a shown in _{C 4} in FIG. 6 is 300μm or more 2700μm or less.

  In this embodiment, the cross-sectional shape of the liquid channel groove 14a is a semi-elliptical shape, but is not limited to this, but is not limited to this, a square such as a square, a rectangle, a trapezoid, a triangle, a semi-circle, a semi-circular bottom, and a semi-elliptical bottom. And so on.

  Further, it is preferable that the liquid passage groove 14a is formed continuously along the edge in the closed space. That is, it is preferable that the liquid passage groove 14a extends annularly over one circumference without being cut by another component. This reduces the factor that hinders the movement of the condensate, so that the condensate can be moved smoothly.

  In the present embodiment, the outer peripheral liquid flow path section 14 is provided, but the outer peripheral liquid flow path section 14 is not necessarily provided, and the shape of the vapor chamber, the relationship with the equipment to which the vapor chamber is applied, the usage environment, and the like. From the viewpoint, the outer peripheral liquid flow path portion 14 may not be provided. In this embodiment, the outer peripheral portion of the closed space is used as a steam flow path, and the heat can be transferred to the outer peripheral portion of the vapor chamber by the steam. In some cases, higher soaking can be achieved.

  Returning to FIG. 2 to FIG. 4, the inner liquid flow path 15 will be described. The inner liquid flow path 15 also functions as a liquid flow path, and is a part of the condensed liquid flow path 3 that passes when the working fluid is condensed and liquefied. FIG. 8A shows a portion indicated by VIIIa in FIG. This figure also shows the cross-sectional shape of the inner liquid flow path 15. FIG. 8B is an enlarged view of the inner liquid flow path portion 15 viewed from the direction indicated by the arrow VIIIb in FIG.

As can be seen from these figures, the inner liquid passage portion 15 is formed on the inner surface 10a of the main body 11 inside the ring of the annular outer liquid passage portion 14 (or the outer peripheral joint portion 13). As can be seen from FIGS. 2 and 3, the inner liquid flow path portion 15 of the present embodiment is a protruding ridge having a curved portion, and a plurality (five in the present embodiment) of the inner liquid flow path portion 15 extends. They are arranged at intervals in a direction different from the direction, and are arranged between the steam flow grooves 16.
Each inner liquid flow path portion 15 is formed with a liquid flow groove 15a which is a groove parallel to the direction in which the inner liquid flow path section 15 extends, and a plurality of liquid flow grooves 15a are formed. They are arranged at predetermined intervals in a direction different from the extending direction. Therefore, as can be seen from FIGS. 4 and 8 (a), in the inner liquid flow path portion 15, in the cross section, the liquid flow groove 15a which is a concave portion and the wall 15b which is a convex portion between the liquid flow grooves 15a have irregularities. It is formed repeatedly.
Here, since the liquid passage groove 15a is a groove, the liquid passage groove 15a has a bottom in a cross-sectional shape thereof, and an opening located on an opposite side facing the bottom.

  By providing a plurality of liquid flow grooves 15a in this manner, the depth and width of each liquid flow groove 15a are reduced, and the flow path cross-sectional area of the condensate liquid flow path 3 (for example, see FIG. 18) is reduced. It can be made smaller to take advantage of the larger capillary forces. On the other hand, by using a plurality of liquid flow grooves 15a, an appropriate internal volume of the condensed liquid flow path 3 as a whole is secured, and a required amount of condensed liquid can be flowed.

  8B, the adjacent liquid passage grooves 15a are formed on the wall 15b in the same manner as in FIG. They communicate with each other through a communication opening 15c provided with an interval. This promotes equalization of the amount of condensed liquid between the plurality of liquid flow grooves 15a, and allows the condensed liquid to flow efficiently. In addition, a communication opening 15 c provided in a wall 15 b adjacent to the steam flow channel groove 16 that forms the steam flow channel 4 connects the steam flow channel 4 and the condensate flow channel 3. Therefore, the condensed liquid generated in the vapor flow path 4 can be smoothly moved to the condensed liquid flow path 3 by forming the communication opening 15c as described later, and the vapor generated in the condensed liquid flow path can be formed. Can be smoothly moved to the steam flow path 4, which also facilitates smooth movement of the working fluid.

7, the communication openings 15c are arranged at different positions in the direction in which the liquid flow grooves 15a extend across one of the liquid flow grooves 15a, following the example of FIG. Is also good.
By providing the communication opening 15c offset in this way, the communication opening 15c does not appear on both sides at the same time when viewed from the working fluid traveling in the condensate flow path 3, and the communication opening 15c appears. Also, at least one side surface always has the wall 15b. Therefore, the capillary force can be continuously obtained. By forming the communication opening 15c offset from this point of view, the capillary force acting on the working fluid can be kept high, so that the working fluid can move more smoothly.

It is preferable that the inner liquid flow path unit 15 having the above configuration further has the following configuration.
3, 4, the width of the inner fluid passage section 15 shown in _{E 10} in FIG. 8 (a) is preferably 100μm or 2000μm or less. Further, the pitch of the plurality of inner liquid flow paths 15 is preferably 200 μm or more and 4000 μm or less. Thereby, the flow resistance of the steam flow path is sufficiently reduced, and the movement of the working fluid in the steam flow path and the movement of the working fluid due to the action of the capillary force in the condensate flow path can be performed in a well-balanced manner.

For liquid flow path grooves 15a, FIG. 8 (a), the it is preferred that the groove width shown in _{F 1} in FIG. 8 (b) is 10μm or more 300μm or less.
The depth of the groove indicated by G in FIG. 8A is preferably 5 μm or more and 200 μm or less. Thereby, the capillary force of the condensate flow path required for the movement of the condensate can be sufficiently exerted. Here, the groove depth G is preferably smaller than the remaining sheet thickness obtained by subtracting the groove depth G from the thickness of the first sheet 10. This makes it possible to more reliably prevent the sheet from being broken when the working fluid is frozen.
From the viewpoint of exhibiting stronger capillary force of the channel, the aspect ratio of the represented flow path section by a value obtained by dividing the F ₁ in G (aspect ratio) is greater than 1.0, or 1.0 than Preferably, it is small. It is preferable F ₁ from the viewpoint of production among them is greater than G, the aspect ratio is preferably greater than 1.3.

Also, the walls 15b, FIG. 8 (a), the it is preferable that the width indicated by _{F 2} in FIG. 8 (b) is 20μm or more 300μm or less. When the width is smaller than 20 μm, the working fluid is liable to be broken due to repeated freezing and melting. There is a risk of being hindered.

For communication opening portion 15c, the size of the communication opening portion along the direction in which the liquid flow path groove 15a shown extend at F ₃ in FIG. 8 (b) is preferably 20μm or more 180μm or less.
Further, it is preferable that the pitch of the communication opening portion 15c adjacent in the direction in which the liquid flow path groove 15a shown extend at _{F 4} in FIG. 8 (b) is 300μm or more 2700μm or less.

  In the present embodiment, the cross-sectional shape of the liquid channel groove 15a is a semi-elliptical shape, but is not limited thereto, and is not limited to a square, a rectangle, a trapezoid, and the like, a triangle, a semi-circle, a semi-circular bottom, and a semi-elliptical bottom. And so on.

  Next, the steam flow channel 16 will be described. The steam passage groove 16 is a portion where the vapor-like and condensed liquid working fluid moves, and forms a part of the steam passage 4. FIG. 3 shows the shape of the steam flow channel 16 in plan view, and FIG. 4 shows the cross-sectional shape of the steam flow channel 16.

As can be seen from these figures, the steam flow channel 16 is formed by a groove formed on the inner surface 10 a of the main body 11 inside the ring of the annular outer liquid flow channel portion 14. More specifically, the vapor flow channel groove 16 of the present embodiment is formed between the adjacent inner liquid flow channel portions 15 and between the outer liquid flow channel portion 14 and the inner liquid flow channel portion 15 and has curved portions. The groove extends. A plurality of (six in the present embodiment) steam flow grooves 16 are arranged in a direction different from the extending direction. Therefore, as can be seen from FIG. 4, the first sheet 10 has a shape in which the inner liquid flow path portion 15 is formed as a convex ridge and the vapor flow groove 16 is formed as a concave ridge.
Here, since the steam flow passage groove 16 is a groove, it has a bottom in a cross-sectional shape thereof, and an opening located on an opposite side facing the bottom.

The steam flow channel 16 may be configured to move the working fluid in the steam flow channel 4 when the steam flow channel 4 is formed in combination with the steam flow channel 26 of the second sheet 20. . Therefore, it is preferable that the steam flow channel 16 further has the following configuration.
3, the width of the steam flow passage 16 shown in _{H 10} in FIG. 4, at least the above-mentioned liquid flow path groove 14a, the width _{C 1} of the liquid flow path grooves 15a, are formed larger than the width _{F 1,} 100 [mu] m or more 2000μm The following is preferred.
On the other hand, the depth of the steam flow passage 16 shown in _{I 10} in FIG. 4, at least the above-mentioned liquid flow path groove 14a, the depth D of the liquid flow path grooves 15a, it is formed larger than the depth G, 10 [mu] m or more 300μm The following is preferred.
Thereby, the stable movement of the working fluid is performed when the steam flow passage is formed, and the flow passage cross-sectional area of the steam flow passage groove is made larger than the liquid flow passage groove. Steam having a larger volume than the condensate can be smoothly moved.

Here, when the steam flow channel 4 is formed by combining the second sheet 20 with the steam flow channel 4 as described later, the width of the steam flow channel 4 is height (size in the thickness direction). It is preferable to be configured so as to have a larger flat shape. _Therefore, the aspect ratio indicated the _{H 10} with the value obtained by dividing the _{I 10} preferably 4.0 or more, and more preferably 8.0 or more.

  In the present embodiment, the cross-sectional shape of the steam flow channel 16 is a semi-elliptical shape, but not limited to this, a square such as a square, a rectangle, a trapezoid, a triangle, a semi-circle, a circular bottom, a semi-elliptical bottom, etc. Is also good.

The steam flow passage groove 17 communicates the plurality of steam flow passage grooves 16, and is combined with the steam flow passage communication groove 27 of the second sheet 20 to form the plurality of steam flow passages 4 formed by the steam flow passage grooves 16 at their end portions. Is a groove that forms a flow path that communicates with. Thereby, movement of the working fluid generated in the steam flow path 4 in the direction in which the inner liquid flow path 15 extends can be performed smoothly.
In addition, this makes it possible to equalize the working fluid in the steam flow path 4 or to carry the steam to a wider range, thereby efficiently condensing the liquid flow path 3 by the liquid flow grooves 14a and the liquid flow grooves 15a. It can be used well.

  As can be seen from FIGS. 2 and 3, the steam flow passage groove 17 of the present embodiment has both ends in the direction in which the inner liquid flow path 15 extends and both ends in the direction in which the steam flow groove 16 extends, and the outer liquid flow path. It is formed between the road portion 14. FIG. 5B shows a cross section orthogonal to the communication direction of the steam flow passage communication groove 17. Since the boundary between the steam flow passage groove 17 and the steam flow groove 16 is not necessarily formed by the shape, the boundary is represented by a dotted line in FIGS. 2 and 3 for simplicity.

The shape of the steam flow passage communication groove 17 is not particularly limited as long as the steam flow passage groove 17 can be connected so as to connect the adjacent steam flow groove 16, and the steam flow passage groove 17 can have the following configuration, for example.
3, the width of the steam channel communicating groove 17 shown in _{J 10} in FIG. 5 (b) is preferably 100μm or 1000μm or less.
Further, the depth of the steam flow path communicating groove 17 shown in _{K 10} 5 (b) is preferably at 10μm or 300μm or less, the same as the depth _{I 10} of the steam flow passage 16 among them Is preferred. Thereby, the manufacture of the first sheet 10 becomes easy.

  In the present embodiment, the cross-sectional shape of the steam flow passage communication groove 17 is a semi-elliptical shape, but is not limited thereto, and is not limited to a square such as a square, a rectangle, or a trapezoid, a triangle, a semi-circle, a semi-circular bottom, a semi-elliptical bottom, or the like. It may be.

In the present embodiment, the first sheet 10 extends in the liquid flow channel 14 a (outer liquid flow channel 14), the liquid flow channel 15 a (inner liquid flow channel 15), and the vapor flow channel 16. It has a curved portion 18c which is a portion where the direction changes. That is, in the first sheet 10, the liquid flow grooves 14a (the outer liquid flow path 14), the liquid flow grooves 15a (the inner liquid flow path 15), and the vapor flow grooves 16 extend linearly in the x direction. A straight portion 18a, a liquid passage groove 14a (outer peripheral liquid passage portion 14), a liquid passage groove 15a (inner liquid passage portion 15), and a straight line portion 18b in which the vapor passage groove 16 extends linearly in the y direction. And a curved portion 18c connecting the liquid flow channel 14a (outer liquid flow channel 14), the liquid flow channel 15a (inner liquid flow channel 15), and the vapor flow channel 16 in the linear portions 18a and 18b. Is provided. Therefore, the curved portion 18c has one end connected to one straight portion 18a and the other end connected to the other straight portion 18b, and the flow changes direction from the x direction to the y direction and from the y direction to the x direction. Thus, the liquid flow channel 14a (outer liquid flow channel 14), the liquid flow channel 15a (inner liquid flow channel 15), and the vapor flow channel 16 are curved.
Here, the boundary between the straight portion and the curved portion may be a point where the flow direction starts to change in each groove. Hereinafter, the same can be considered. FIG. 11A is an enlarged view of FIG. 3 focusing on the curved portion 18c.

  As can be clearly understood from FIGS. 3 and 11 (a), in the present embodiment, the width of the steam flow channel 16 is formed larger in the curved portion 18c than in the straight portions 18a and 18b. According to this, the flow resistance can be reduced at the curved portion 18c where the flow resistance increases due to the curvature of the flow path, and the flow resistance decreases as a whole of the vapor chamber. You can improve your ability. At this time, the width may be constant in the range of the curved portion 18c. Thereby, the flow resistance of the working fluid can be kept low.

  As described above, means for making the width of the steam flow channel 16 in the curved portion 18c larger than the width of the steam flow channel 16 in the straight portion 18a and the straight portion 18b is not particularly limited. In the present embodiment, the width of the outer liquid passage portion 14 of the portion belonging to the curved portion 18c and the width of the inner liquid passage portion 15 are changed to the outer liquid passage portion 14 of the portion belonging to the linear portion 18a and the straight portion 18b, and the inner side. This is achieved by making the width smaller than the width of the liquid flow path portion 15. In this case, the width of the liquid flow channel 14a of the outer liquid flow channel 14 and the width of the liquid flow channel 15a of the inner liquid flow channel 15 may be reduced at this portion. The number of the flow grooves 15a may be reduced.

  In addition, the width of the outer liquid passage portion 14 belonging to the curved portion 18c and the width of the inner liquid passage portion 15 are changed to the outer liquid passage portion 14 belonging to the linear portions 18a and 18b, and the inner liquid passage portion. The width of the steam flow channel 16 in the curved portion 18c may be made larger than the width of the steam flow channel 16 in the straight portion 18a and the straight portion 18b while the width of the steam flow channel 16 is kept the same. FIGS. 9A to 9C show diagrams for explanation as specific examples.

9 (a) to 9 (c) are diagrams illustrating one steam flow channel groove 16 by focusing on it. The same applies to the other steam flow grooves 16.
The meanings of the symbols shown in FIGS. 9A to 9C are as follows.
Vapor flow passage 16 in the curved portion 18c, the inner wall _{w in} the bending is the radius of curvature _{r in,} the center of which is an arc-shaped _{O 1.}
The steam flow channel groove 16 has a curved portion 18c, and a curved outer wall w _out has a curved radius r _out , and the center thereof is O ₁ , O ₂ , or O ₃ depending on the form as described later. It is arc-shaped.
-Where the width of the steam flow channel 16 in the straight portions 18a and 18b is α, the width of the steam flow channel 16 is increased to β in the curved portion 18c (α <β).
- curve shown by the dotted line is a virtual line when the width of the steam flow passage 16 is maintained α even curved portion 18c, the radius of curvature at this time is r _c, the circle the center of O ₁ It is arc-shaped.
Here, the radius of the curve is considered as a circle passing through a total of three points, that is, two points at which the directions of the walls (inner and outer walls) in the curved part have started to change, and one point at the center of the two points. The radius of the circle can be the radius of curvature. When the curve is regarded as a part of a circle or an ellipse, as shown in FIGS. 9 and 11, the center of the circle or the ellipse (that is, the O ₁ , O ₂ , O ₃ side) with respect to the curve. ) Is defined as “inside” of the curved portion, and the side opposite to the center of the circle or ellipse with respect to the curve is defined as “outside” of the curve. In addition, the shape of the curve is not limited to a shape like a part of a perfect circle, and may be a shape like a part of an ellipse. The shape may be a straight line. Hereinafter, the shape relating to the curved portion can be similarly considered.

Example of FIG. 9 (a), in the curved portion 18c, along with the radius _{r out} of the curved outer wall _{w out} of the steam flow passage 16 is greater than the radius _{r c} of the curved _(r out> _{r c),} the center Is O ₁ .

Example of FIG. 9 (b), in the curved portion 18c, while the radius _{r out} of the curved outer wall _{w out} of the steam flow passage 16 are the same _(r out = _{r c)} and the radius of curvature _{r c,} the center there is in _{O 2} shifted to the steam flow passage 16 side than the _{O 1.}

Example of FIG. 9 (c), in the curved portion 18c, smaller than the radius _{r out} is the radius of curvature _{r in} and the curvature radius _{r c} of the curvature of the outer wall _{w out} of the steam flow passage 16 _(r out _{<r in} < r _c), the center is in the _{O 3} shifted to the steam flow passage 16 side than the _{O 1.}

In the examples of FIGS. 9A and 9B, a straight portion and an arc portion are connected by one bending portion on the outer wall w _out . However, the present invention is not limited to this, and it may be configured such that the one refracting portion is formed into a large number of small refracting portions or curved so as to be connected so that the direction changes gradually and smoothly.

  The width of the steam flow channel groove 16 in the curved portion 18c is not particularly limited as long as the flow resistance can be reduced, but is not less than 10% and not more than 100% as compared with the straight portion 18a and the straight portion 18b. Preferably, the width is large. If it is less than 10%, the flow resistance may not be sufficiently reduced. On the other hand, if the width of the steam flow channel groove is increased by more than 100% in the curved portion 18c as compared with the straight portions 18a and 18b, the flow resistance of the straight portion may be increased.

Further, in the above description, the mode has been described focusing on the width of the steam flow channel groove, but instead or additionally, the depth of the steam flow channel groove 16 in the curved portion 18c is compared with the straight portion 18a and the straight portion 18b. May be deeper. In the mode by changing the depth direction, the expansion in the plane direction (xy direction) is suppressed, so that a large number of portions where the condensate flow paths are arranged are secured to improve the heat transport capability, and the outer peripheral joint is achieved. In this case, a large portion can be taken and the reliability of the withstand voltage can be improved. At this time, the depth may be constant in the range of the curved portion 18c. Thereby, the flow resistance of the working fluid can be kept low.
The difference in the depth is not particularly limited as long as the flow resistance can be reduced, but it is desirable that the steam flow channel groove be 10% or more deeper in the curved portion than in the straight portion. If it is less than 10%, the flow resistance may not be sufficiently reduced.

Further, as shown in FIG. 10, a plurality of columns 16a may be arranged in the steam flow channel groove 16 in the curved portion 18c so as to stand up from the bottom at the center in the width direction. This serves as a pillar for supporting the first sheet 10 and the second sheet 20 of the vapor chamber 1. Therefore, it is possible to suppress a decrease in strength due to an increase in the width of the steam flow channel due to an increase in the width of the steam flow channel groove of the curved portion 18c. Specifically, the steam flow path is crushed due to insufficient strength when joining or depressurizing when the first sheet 10 and the second sheet 20 are combined into the vapor chamber 1 and when assembling the vapor chamber into the electronic device. Can be prevented.
From such a viewpoint, as shown in FIG. 10, columns 16 a can be provided in the long steam flow channel 16. However, the present invention is not limited to this, and pillars 16a may be provided in any of the other steam flow grooves 16 as needed, or pillars 16a may be provided in all the steam flow grooves 16.

  In the present embodiment, as shown in FIG. 11A, the width of the steam flow channel groove 16 is formed so as to change stepwise at the connection portion between the curved portion and the straight portion. On the other hand, in the example shown in FIG. 11B, the width of the steam flow channel groove 16 is formed such that the width of the groove gradually changes due to the tapered inclined surface at the connection portion between the curved portion and the straight portion. Have been. According to this, it is possible to prevent the generation of a vortex when the working fluid passes through the connection portion, and it is possible to further suppress the flow resistance.

Further, in the above embodiment, the width of the plurality of steam flow grooves 16 in the curved portion 18c is the same, but the width is not limited to this and may be changed for each steam flow groove.
In this case, for example, the groove width of the steam flow channel groove having a large radius of curvature may be larger than the groove width of the steam flow channel groove having a small radius of curvature. Thereby, the flow resistance of the steam flow path in which the moving distance of the steam is long and the curvature radius of the curvature is large can be reduced.
Further, the groove width of the steam flow channel groove having a smaller curvature radius of curvature may be larger than the groove width of the steam flow channel groove having a larger curvature radius of curvature. Thereby, the flow resistance of the steam flow path of the curved portion due to the small radius can be reduced.
Further, the groove width of the steam flow channel groove having a large radius and the steam flow channel groove having a small radius may be increased with respect to the steam flow channel arranged at the center.
With the above-described means, it is possible to further reduce the difference in the flow resistance among the plurality of steam flow grooves, thereby improving the balance of movement of the working fluid and increasing the heat transport capacity.

In addition to the above, the first sheet 10 may have the following configuration.
As can be seen from FIG. 3, in the curved portion 18c of the present embodiment, the liquid flow grooves 14a, the liquid flow grooves 15a, and the vapor flow grooves 16 are arranged in one of the arrangement directions in the direction in which the respective flow grooves are arranged. The configuration is such that the radius of curvature of the steam flow path on the side is larger than the radius of curvature of the steam flow path on the other side in the arrangement direction. Such a configuration may be adopted.

  Among them, in the present embodiment, each of the plurality of grooves is curved so as to draw a concentric arc. However, the present invention is not limited to this, and the center position of the arc may be shifted. Further, the curved portion 18c is configured such that the radius increases as the length of the flow channel increases.

  When a plurality of curved flow paths are arranged in the vapor chamber, the flow path length becomes shorter toward the inside and the flow path length becomes longer toward the outside, so that the difference in flow resistance between the inside and the outside becomes large. This difference in flow resistance causes the balance of movement of the working fluid in the vapor chamber to be poor, and is one of the reasons why a sufficient heat transport ability cannot be exhibited. On the other hand, the configuration having the radius of curvature as described above makes it possible to reduce the difference in flow resistance between the inside and the outside, particularly in the steam flow channel 16. As a result, the balance of movement of the working fluid is improved, and the heat transport capacity can be increased.

  However, the present invention is not limited to this, and as shown in FIG. 12, the curvature radius of the plurality of steam flow grooves 16 in the curved portion 18c may be the same.

Further, in the curved portion 18c, the communication opening 14c and the communication opening 15c provided in the wall 14b and the wall 15b that partition the liquid passage groove 14a and the liquid passage groove 15a from the vapor passage groove 16 (FIG. 6). 8 (b)), the pitch can be configured to be different from other portions (the linear portions 18a and the linear portions 18b). In this case, the pitch of the communication openings in the curved portion may be larger or smaller than the pitch of the curved portions in the straight portion. Which form to use can be adopted by comprehensively judging the form that can reduce the flow resistance in consideration of the influence of the overall shape of the vapor chamber, the position of the heat source, and the like. Alternatively, regarding the curved portion 18c, the communication opening 14c and the communication opening 15c provided in the wall 14b and the wall 15b that partition the liquid passage groove 14a and the liquid passage groove 15c from the vapor passage groove 16 are formed. It is not necessary to provide it.
In a configuration in which the pitch of the communication opening of the curved portion is larger than the pitch of the communication opening of the linear portion, the working fluid flowing through the steam flow channel 16 (steam flow channel 4) is connected to the communication opening 14c by the bending portion 18c. It is possible to suppress entry into the opening 15c. In the curved portion 18c, a force acts on the working fluid moving in the steam flow channel 16 (steam flow channel 4) to flow directly into the communication openings 14c and 15c depending on the flow direction. The flow resistance tends to increase due to entry into the condensate flow path 3 and unevenness of the communication opening 14c and the communication opening 15c. In contrast, the pitch of the communication opening 14c and the communication opening 15c in contact with the steam flow channel 16 in the curved portion 18c is increased, and the communication opening 14c and the communication opening 15c in contact with the steam flow channel 16 are eliminated. This can suppress such an increase in flow resistance, further reduce the difference in flow resistance between the steam flow channels 16 (steam flow channels 4), improve the balance of movement of the working fluid, In some cases, transportation capacity can be increased.
On the other hand, if the pitch of the communication opening of the curved portion is smaller than the pitch of the communication opening of the straight portion, the chance that the steam flowing through the steam flow channel (steam flow channel) strongly hits the wall surface in the bent portion increases. , Tends to condense. At this time, by making the pitch of the communication opening of the curved portion smaller than the pitch of the communication opening of the linear portion, the number of the communication openings is increased, and the condensate is smoothly supplied to the liquid flow channel (condensate flow channel). ), And it is possible to prevent the vapor flow passage from being closed by the condensed liquid. As a result, an increase in flow resistance can be suppressed, the difference in flow resistance between the steam flow channels (steam flow channels) can be further reduced, the balance of movement of the working fluid can be improved, and the heat transport capability can be increased. There are cases.

Next, the second sheet 20 will be described. In the present embodiment, the second sheet 20 is also a sheet-like member as a whole, and is curved in an L shape in plan view. FIG. 13 is a perspective view of the second sheet 20 viewed from the inner surface 20a side, and FIG. 14 is a plan view of the second sheet 20 viewed from the inner surface 20a side. FIG. 15 shows a cut surface of the second sheet 20 when cut along XIII-XIII in FIG. FIG. 16 shows a cut surface of the second sheet 20 when cut along XIV-XIV in FIG.
The second sheet 20 has an inner surface 20a, an outer surface 20b opposite to the inner surface 20a, and a side surface 20c that forms a thickness across the inner surface 20a and the outer surface 20b, and a pattern in which the working fluid moves to the inner surface 20a side. Are formed. As will be described later, the inner surface 20a of the second sheet 20 and the inner surface 10a of the first sheet 10 are overlapped and joined so as to face each other to form a hollow portion, in which a working fluid is sealed and sealed. A space 2 is formed.

  The thickness of the second sheet 20 is not particularly limited, but is preferably 0.01 mm or more and 1.0 mm or less, and more preferably 0.05 mm or more and 0.2 mm or less. This can increase the number of scenes that can be applied as a thin vapor chamber.

The second sheet 20 has a main body 21 and an injection section 22. The main body 21 has a sheet shape that forms a portion where the working fluid moves, and in this embodiment, is an L-shape having a portion that curves in a plan view.
The injection part 22 is a part for injecting a working fluid into a hollow part formed by the first sheet 10 and the second sheet 20, and in the present embodiment, has a rectangular shape in plan view projecting from an L-shape in plan view of the main body 21. It is sheet-shaped. In the present embodiment, the injection portion 22 of the second sheet 20 has an injection groove 22a formed on the inner surface 20a side, and the inside of the main body 21 from the side surface 20c of the second sheet 20 (a hollow portion, a portion to be the closed space 2). Is in communication with

  On the inner surface 20a side of the main body 21, a structure for moving the working fluid is formed. Specifically, on the inner surface 20 a side of the main body 21, an outer joint portion 23, an outer liquid passage portion 24, an inner liquid passage portion 25, a steam passage groove 26, and a steam passage communication groove 27 are provided. ing.

The outer peripheral joint 23 is a surface formed on the inner surface 20 a side of the main body 21 along the outer periphery of the main body 21. The outer peripheral joint 23 overlaps the outer peripheral joint 13 of the first sheet 10 and is joined (diffusion joined, brazed, or the like) to form a hollow portion between the first sheet 10 and the second sheet 20. Here, the working fluid is sealed therein to form the closed space 2.
14, 15, it is preferable that the width of the outer peripheral joint 23 shown in _{A 20} in FIG. 16 is the same as the width _{A 10} of the outer joint portion 13 of the body 11 described above.

  The outer peripheral liquid flow path portion 24 functions as a liquid flow path portion and is a portion that constitutes a part of the condensed liquid flow path 3 (see, for example, FIG. 18) that is a flow path that passes when the working fluid is condensed and liquefied. is there.

The outer liquid passage portion 24 is formed along the inner surface of the outer joint portion 23 of the inner surface 20 a of the main body 21, and is formed so as to form an annular shape along the outer periphery of the closed space 2. In this embodiment, as can be seen from FIGS. 15 and 16, the outer peripheral liquid flow path portion 24 of the second sheet 20 has a flat surface and is flush with the outer peripheral joint portion 23 before being joined to the first sheet 10. As a result, the condensed liquid flow path 3 is formed by closing the opening of at least a part of the liquid flow grooves 14a of the plurality of liquid flow grooves 14a of the first sheet 10 described above. The detailed mode regarding the combination of the first sheet 10 and the second sheet 20 will be described later.
Since the outer peripheral joint portion 23 and the outer peripheral liquid flow path portion 24 are flush with each other in the second sheet 20 in this manner, there is no boundary line that distinguishes the two from each other structurally. However, for the sake of simplicity, the boundary between the two is indicated by a dotted line in FIGS.

It is preferable that the outer liquid passage portion 24 has the following configuration.
14, 15, the width B ₂₀ of the outer fluid passage section 24 shown in FIG. 16 is not particularly limited, and may the same as the width B ₁₀ of the outer fluid flow passage portion 14 of the first sheet 10 , May be different. In this embodiment are the same as the width _{B 10} and the width _{B 20.}
If the width B ₂₀ less than the width B _10, at least part of the outer circumferential fluid flow path portion 14, the opening of the liquid flow path grooves 14a are opened without being closed by the outer peripheral liquid flow path portion 24, condensed from here Since the liquid easily enters and the steam easily emerges, the working fluid can be moved more smoothly.

  In the present embodiment, the outer liquid passage portion 24 of the second sheet 20 is configured to have a flat surface. However, the present invention is not limited to this. Good. At this time, the condensate flow path 3 can be formed by overlapping the liquid flow path groove of the first sheet and the liquid flow path groove of the second sheet.

  Further, in the present embodiment, as described in the first sheet, the outer peripheral liquid flow path portion 24 is not necessarily provided, and a form in which the outer peripheral liquid flow path portion 24 is not provided may be employed.

  Next, the inner liquid passage 25 will be described. The inner liquid flow path 25 is also a liquid flow path, and is one part of the condensed liquid flow path 3.

As can be seen from FIGS. 13 to 16, the inner liquid passage portion 25 is formed on the inner surface 20 a of the main body 21 inside the annular ring of the outer peripheral liquid passage portion 24. The inner liquid flow path portion 15 of the present embodiment is a protruding ridge having a curved portion, and has an interval in a direction different from a direction in which a plurality (five in the present embodiment) of the inner liquid flow path portions 25 extend. And arranged between the steam flow grooves 26.
In the present embodiment, each inner liquid passage portion 25 is formed such that the surface on the inner surface 20a side becomes a flat surface before joining with the first sheet 10. Thereby, the condensed liquid flow path 3 is formed by closing the opening of at least a part of the liquid flow grooves 15a of the plurality of liquid flow grooves 15a of the first sheet 10 described above.
In the case where a groove for forming the condensed liquid flow path 3 is not formed in the inner liquid flow path section 25 as in the present embodiment, the thickness of the second sheet 20 is calculated based on the thickness of the first sheet 10. It is preferable that the thickness be equal to or greater than the depth obtained by subtracting the depth G (see FIG. 8A) of the flow channel groove 15a. Thereby, it is possible to prevent breakage (tear) on the second sheet side in the vapor chamber.

  In the present embodiment, the inner liquid flow path portion 25 of the second sheet 20 is configured to have a flat surface. However, the present invention is not limited to this. Is also good. At this time, the condensate flow path 3 can be formed by overlapping the liquid flow path groove of the first sheet and the liquid flow path groove of the second sheet.

14, the width E ₂₀ of the inner fluid passage section 25 shown in FIG. 15 is not particularly limited, and may the same as the width E ₁₀ of the inner fluid flow path portion 15 of the first sheet 10, or different You may. In this embodiment are the same as the width _{E 10} and width _{E 20.}
It is possible to reduce the influence of positional deviation at the time of bonding and the width E ₂₀ and width E ₁₀ are different. In the case where the width E ₂₀ smaller than the width E _10, at least a portion of the inner fluid passage 15, the opening of the liquid flow path grooves 15a are opened without being closed by the inner fluid flow path portion 25 Since the condensed liquid can easily enter from here and the generated steam can easily come out, the working fluid can be moved more smoothly.

  Next, the steam flow channel 26 will be described. The steam flow channel 26 is a part where the vapor-like and condensed liquid working fluid moves, and forms a part of the steam flow channel 4. FIG. 14 shows the shape of the steam flow channel 26 in plan view, and FIG. 15 shows the cross-sectional shape of the steam flow channel 26.

As can be seen from these drawings, the steam flow channel 26 is formed by a groove having a curved portion formed on the inner surface 20 a of the main body 21 inside the ring of the annular outer liquid flow channel portion 24. Specifically, the steam flow channel groove 26 of the present embodiment is a groove formed between the adjacent inner liquid flow channel portions 25 and between the outer peripheral liquid flow channel portion 24 and the inner liquid flow channel portion 25. A plurality of (six in this embodiment) steam flow grooves 26 are arranged in a direction different from the direction in which the steam flow grooves 26 extend. Therefore, as can be seen from FIG. 14, the second sheet 20 is formed with a ridge having the inner liquid passage portion 25 as a protrusion, and a ridge having the steam passage groove 26 as a recess. It has a repeated shape.
Here, since the steam flow passage groove 26 is a groove, it has a bottom portion and an opening in a portion on the opposite side facing the bottom portion in the cross-sectional shape.

The steam flow channel 26 is preferably arranged at a position overlapping the steam flow channel 16 of the first sheet 10 in the thickness direction when combined with the first sheet 10. Thereby, the steam passage 4 can be formed by the steam passage groove 16 and the steam passage groove 26.
The width of the steam flow channel 26 indicated by H ₂₀ in FIGS. 14 and 15 is not particularly limited, and may be the same as or different from the width H ₁₀ of the steam flow channel 16 of the first sheet 10. Is also good. In this embodiment are the same as the width _{H 10} and width _{H 20.}
When the width H ₂₀ and width H ₁₀ are different, it is possible to reduce the influence of positional deviation at the time of bonding. Note that when increasing the width H ₂₀ than the width H _10, at least a portion of the inner fluid passage 15, the opening of the liquid flow path grooves 15a are opened without being closed by the inner fluid flow path portion 25 Since the condensed liquid can easily enter from here and the vapor can easily be emitted, the working fluid can be moved more smoothly.
On the other hand, the depth of the steam flow path groove 26 shown in _{I 20} 15 is preferably 10μm or more 300μm or less.

Here, when the steam passage 4 is formed in combination with the first sheet 10 as described later, the width of the steam passage 4 has a height (a size in a thickness direction). It is preferable to be configured so as to have a larger flat shape. _Therefore, the aspect ratio indicated the _{H 20} with the value obtained by dividing the _{I 20} preferably 4.0 or more, and more preferably 8.0 or more.

  In this embodiment, the cross-sectional shape of the steam flow channel groove 26 is a semi-elliptical shape, but may be a square such as a square, a rectangle, or a trapezoid, a triangle, a semi-circle, a semi-circular bottom, a semi-elliptical bottom, or the like.

  The steam flow path communication groove 27 is a groove that is combined with the steam flow path communication groove 17 of the first sheet 10 to form a flow path that communicates the ends of the plurality of steam flow paths 4 with the steam flow path groove 26. . Thereby, the movement of the working fluid generated in the steam flow path 4 in the direction in which the inner liquid flow path 25 extends is performed in a well-balanced manner. In addition, the working fluid in the steam flow path 4 can be equalized, and the steam can be transported to a wider range, so that many condensate flow paths 3 can be used efficiently. It becomes possible to make it smoother.

  As can be seen from FIGS. 14 and 16, both ends of the vapor passage communication groove 27 in the direction in which the inner liquid passage portion 25 extends and both ends in the direction in which the vapor passage groove 26 extends, as shown in FIGS. It is formed between the road portion 24. FIG. 16 shows a cross section orthogonal to the communication direction of the steam flow passage communication groove 27.

14, the width of the steam channel communicating groove 27 shown in J ₂₀ 16 is not particularly limited, and may be the same as the width J ₁₀ steam channel communication groove 17 of the first sheet 10 and, it may be different from the width _{J 10.} Incidentally, when greater than the width J ₁₀ width J ₂₀ is formed at least in part, the opening of the liquid flow path grooves 14a are a part of the steam flow path 4 of the outer circumferential fluid flow path portion 14 of the first sheet 10 As a result, the condensed liquid can easily enter, and the generated vapor can be easily emitted, so that the working fluid can be moved more smoothly.

The size of the width _{J 20} is preferably 1000μm or less the range of 100 [mu] m, the depth of the steam flow path communicating groove 27 shown in _{K 20} 14 is preferably 10μm or more 300μm or less.

  In the present embodiment, the cross-sectional shape of the steam flow passage communication groove 27 is a semi-elliptical shape, but is not limited thereto, and is not limited to a square such as a square, a rectangle, and a trapezoid, a triangle, a semi-circle, a semi-circular bottom, and a semi-elliptical bottom. There may be.

  Further, in the present embodiment, the second sheet 20 includes a curved portion 28c which is a portion in which the extending direction changes in the outer peripheral liquid flow path portion 24, the inner liquid flow path portion 25, and the vapor flow channel groove 26. . In other words, as can be seen from FIG. 14, the second sheet 20 includes a linear portion 28a in which the outer liquid passage 24, the inner liquid passage 25, and the vapor passage groove 26 extend linearly in the x direction. The channel portion 24, the inner liquid channel portion 25, and the steam channel groove 26 extend linearly in the y direction, and the outer liquid channel portion 24 and the inner liquid channel in the linear portions 28a and 28b. And a curved portion 28c connecting the portion 25 and the steam flow channel 26. Accordingly, the curved portion 28c has one end connected to one straight portion 28a and the other end connected to the other straight portion 28b, and the flow changes direction from the x direction to the y direction and from the y direction to the x direction. Thus, the outer liquid passage 24, the inner liquid passage 25, and the vapor passage groove 26 are curved.

  As can be seen from FIG. 14, in the curved portion 28c of the present embodiment, the outer liquid passage portion 24, the inner liquid passage portion 25, and the vapor passage groove 26 are formed in the curved portion 18c of the first sheet 10 described above. Can be considered as well.

Next, the structure when the first sheet 10 and the second sheet 20 are combined to form the vapor chamber 1 will be described. From this description, the arrangement, size, shape, and the like of each component of the first sheet 10 and the second sheet 20 are further understood.
FIG. 17 illustrates a cut surface obtained by cutting the vapor chamber 1 in the thickness direction along the y direction indicated by XV-XV in FIG. This drawing is a combination of the drawing shown in FIG. 4 of the first sheet 10 and the drawing shown in FIG. 15 of the second sheet 20 to show a cut surface of the vapor chamber 1 in this portion.
FIG. 18 shows an enlarged view of the portion indicated by XVI in FIG.
FIG. 19 illustrates a cut surface cut in the thickness direction of the vapor chamber 1 along the x direction indicated by XVII-XVII in FIG. This drawing is a combination of the drawing shown in FIG. 5B of the first sheet 10 and the drawing shown in FIG. 16 of the second sheet 20 to show a cut surface of the vapor chamber 1 at this portion. It is.

  As can be seen from FIGS. 1 (a), 1 (b), and FIGS. 17 to 19, the first sheet 10 and the second sheet 20 are arranged so as to be overlapped and joined to form the vapor chamber 1. ing. At this time, the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20 are arranged so as to face each other, the main body 11 of the first sheet 10 and the main body 21 of the second sheet overlap, and The injection part 12 and the injection part 22 of the second sheet 20 overlap.

  With such a laminated body of the first sheet 10 and the second sheet 20, the components included in the main body 11 and the main body 21 are arranged as shown in FIGS. Specifically, it is as follows.

The effect of the vapor chamber 1 of this embodiment is particularly large when the vapor chamber 1 is thin. Figure 1 From this point of view, the thickness of the vapor chamber 1 shown in _{L 0} in FIG. 17 is 1mm or less, more preferably 0.4mm or less, more preferably 0.2mm or less. By setting the thickness to 0.4 mm or less, in the electronic device in which the vapor chamber 1 is installed, the vapor chamber can be installed inside the electronic device without processing (for example, forming a groove) for forming a space in which the vapor chamber is arranged. Increase. According to this embodiment, even in such a thin vapor chamber, the thermal performance is maintained while the strength is high and the vapor chamber is resistant to deformation.

  On the other hand, the outer peripheral joint 13 of the first sheet 10 and the outer peripheral joint 23 of the second sheet 20 are arranged so as to overlap with each other, and both are joined by joining means such as diffusion joining or brazing. Thereby, the closed space 2 is formed between the first sheet 10 and the second sheet 20.

The outer liquid passage portion 14 of the first sheet 10 and the outer liquid passage portion 24 of the second sheet 20 are arranged so as to overlap. Thus, the condensed liquid flow path 3 through which the condensed liquid in which the working fluid is condensed and liquefied is formed by the liquid flow path groove 14a of the outer liquid flow path 14 and the outer liquid flow path 24.
Similarly, the inner liquid flow path 15, which is a ridge of the first sheet 10, and the inner liquid flow path 25, which is a ridge of the second sheet 20, are arranged to overlap. As a result, the condensed liquid passage 3 through which the condensed liquid flows is formed by the liquid passage groove 15a of the inner liquid passage 15 and the inner liquid passage 25.

Here, it is preferable that the condensate flow path 3 has a flat cross-sectional shape as the vapor chamber 1 becomes thinner. As a result, the capillary force can be increased, and the condensate can move more smoothly, so that the heat transport capability can be maintained at a high level. More specifically, a ratio (aspect ratio) expressed by a value obtained by dividing the width of the condensate flow path 3 by the height is preferably greater than 1.0 and 4.0 or less.
The width of the condensate flow path 3, in the present embodiment is analogous to the width _{F 1} of Ekiryuromizo 15a, is preferably 10μm or more 300μm or less. If the width is smaller than 10 μm, the flow path resistance increases, and the transport capacity may be reduced. On the other hand, when the width is larger than 300 μm, the capillary force is reduced, and the transport capacity may be reduced.
In this embodiment, the height of the condensed liquid flow path 3 is in accordance with the depth G of the liquid flow path groove 15a, but is preferably 5 μm or more and 200 μm or less. Thereby, the capillary force of the condensate flow path necessary for the movement can be sufficiently exerted. The height is preferably equal to or less than the thickness (thickness) of the first sheet 10 and the second sheet 20 on one side and the other side in the thickness direction (z direction) across the condensate flow path 3. . Thereby, breakage (breakage) of the vapor chamber caused by the condensate flow path 3 can be further prevented.

  The cross-sectional shape of the condensed liquid flow path 3 is a semi-elliptical shape due to the cross-sectional shapes of the liquid flow grooves 14a and the liquid flow grooves 15a, but is not limited thereto, and is not limited to a square, a rectangle, a trapezoid, etc. The bottom may be semi-circular, the bottom may be semi-elliptical, or a combination thereof. It can also be shaped like a crescent.

  In this embodiment, since the liquid flow channel 14a and the liquid flow channel 15a are provided only in the first sheet 10, the height of the condensed liquid flow channel is the depth of the liquid flow channel 14a and the liquid flow channel 15a. However, the present invention is not limited thereto, and the second sheet 20 may be provided with a liquid channel groove. In this case, the condensate flow path is formed by overlapping the liquid flow path groove of the first sheet and the liquid flow path groove of the second sheet, and the condensate liquid according to the total depth of both liquid flow path grooves is formed. It is the height of the channel.

When the condensate flow path is formed by providing the liquid flow path grooves on the first sheet and the second sheet and overlapping them, the condensate flow path is formed as shown in FIGS. 20 (a) to 20 (c). Can be configured.
The example of FIG. 20A is an example in which the liquid passage grooves of the first sheet and the second sheet are arranged at the same width and the same position.
The example of FIG. 20B is an example in which the width of the liquid flow channel in the second sheet is larger than the width of the liquid flow channel in the first sheet, and the positions coincide. In this example, a convex portion is formed in the condensate flow path as indicated by P, so that the capillary force can be improved, and the power of the condensate movement (condensate supply force) can be increased.
The example of FIG. 20C is an example in which the liquid flow channel grooves of the first sheet and the second sheet have the same width, but are displaced. Also in this example, a convex portion is formed in the condensed liquid flow path as indicated by P, so that the capillary force can be improved, and the condensed liquid moving force (condensed liquid supply force) can be increased.

  Further, as described above, the condensed liquid flow path 3 is provided with the communication opening 14c and the communication opening 15c. As a result, the plurality of condensed liquid passages 3 communicate with each other, the condensed liquid is equalized, and the condensed liquid is efficiently moved. In addition, the communication opening 14c and the communication opening 15c which are adjacent to the steam flow path 4 and communicate the steam flow path 4 and the condensed liquid flow path 3 are capable of smoothly flowing the condensed liquid generated in the steam flow path 4 into the condensed liquid. The working fluid can be moved to the passage 3 and the steam generated in the condensed liquid passage 3 can be smoothly moved to the steam passage 4 so that the working fluid can be moved quickly.

  In addition, it is preferable that the condensed liquid flow path 3 formed by the outer peripheral liquid flow path section 14 and the outer peripheral liquid flow path section 24 is formed in an annular shape continuously along the edge in the closed space 2. In other words, the condensed liquid flow path 3 formed by the outer liquid flow path section 14 and the outer liquid flow path section 24 may extend in an annular shape over one circumference without being cut by other components. preferable. As a result, factors that hinder the movement of the condensed liquid can be reduced, and the condensed liquid can be smoothly moved.

  In the present embodiment, as described above, the condensate flow path is formed by providing a condensate flow path groove in the sheet and thereby forming a flow path, but instead a means for generating a capillary force is separately provided here. It may be arranged to form a condensate flow path. For this purpose, for example, a so-called wick such as a mesh (net-like) material, a nonwoven fabric, a stranded wire, and a sintered body of metal powder can be arranged.

The opening of the steam passage groove 16 of the first sheet 10 and the opening of the steam passage groove 26 of the second sheet 20 overlap so as to face each other to form a passage, and this becomes the steam passage 4.
Here, it is preferable that the cross-sectional shape of the steam flow path 4 be flat as the vapor chamber 1 becomes thinner. As a result, even if the thickness is reduced, the surface area in the flow path can be secured, and the heat transport capability can be maintained at a high level. More specifically, the width W _B of the steam flow path 4 shown in FIG. _18, the height H _B, the ratio represented by the value obtained by dividing the W _B with H _B (aspect ratio) is 2.0 or more Preferably, there is. From the viewpoint of ensuring a higher heat transport capability, the ratio is more preferably equal to or greater than 4.0.

  As can be seen from FIG. 17, an overlapping flow path is formed so that the opening of the steam flow path communication groove 17 of the first sheet 10 and the opening of the steam flow path communication groove 27 of the second sheet 20 face each other. The plurality of steam flow paths 4 formed by the grooves 16 and the steam flow path grooves 26 are communicated at their ends to form a flow path for performing a well-balanced movement of the working fluid.

As described above, the condensed liquid flow path 3 and the vapor flow path 4 are formed in the closed space 2 of the vapor chamber 1 by the shape of the first sheet 10 and the second sheet. FIG. 18 shows a diagram focusing on the condensate flow path 3 and the vapor flow path formed in the closed space 2.
As can be seen from FIGS. 18 and 21, the vapor chamber 1 has a shape in which a plurality of condensed liquid passages 3 are arranged between two vapor passages 4. As a result, the condensate flow path 3 through which the condensate mainly flows and the vapor flow path 4 through which the vapor and the condensate move are separated and alternately arranged, and the smooth movement of the working fluid is assisted.

  By the steam flow path 4 and the condensed liquid flow path 3, the working fluid in the state of the vapor and the condensed liquid moves in the steam flow path 4, and heat is efficiently transferred and diffused. On the other hand, since the condensed liquid moves efficiently by the capillary force by the condensed liquid flow path 3 provided separately from the vapor flow path 4, the occurrence of dryout can be suppressed.

  Further, in the vapor chamber 1, the condensed liquid flow path 3 and the vapor flow path 4 extend in different directions in which two straight portions 6 are connected by a curved portion 7. By forming such a flow path, when the vapor chamber is placed in the electronic device, even if it is not possible to form a flow path only in a straight line due to restrictions on the placement, Is provided, the heat generated from the heat source can be efficiently moved to the separated position.

  The curved portion 7 is formed by the curved portion 18c of the first sheet 10 and the curved portion 28c of the second sheet 20. Therefore, the bending portion 7 has one end connected to one straight portion 6 and the other end connected to the other straight portion 6, and the flow is directed from the x direction to the y direction and from the y direction to the x direction. The condensate flow path 3 and the vapor flow path 4 are curved so as to be changed.

In the present embodiment, the cross-sectional area (width in the present embodiment) of the steam flow channel 4 is formed larger in the curved portion 7 than in the straight portion 6. According to this, the flow resistance in the curved portion 7 where the flow resistance increases due to the bending of the steam flow path 4 can be reduced, and the flow resistance is reduced as a whole of the vapor chamber, so that the movement of the working fluid becomes smoother. Heat transport capacity can be increased. At that time, the flow path cross-sectional area of the steam flow path 4 in the bending portion 7 may be constant at least within the range of the bending portion 7. Thereby, the flow loss of the working fluid due to the enlargement or reduction of the flow path cross section can be reduced.
Here, the “flow path cross-sectional area” is a cross-sectional area of the flow path in a plane orthogonal to the direction in which the flow path extends.

  The means, degree, and concept of increasing the cross-sectional area (width in the present embodiment) of the steam flow path 4 in the curved portion 7 are the same as those described for the curved portion 18c of the first sheet 10 described above. is there.

  In addition, as can be seen from FIG. 21, in the curved portion 7 of the present embodiment, the condensed liquid flow path 3 and the vapor flow path 4 have a radius of curvature of the outer vapor flow path in the direction in which these flow paths are arranged. Is configured to be larger than the radius of curvature of the inner steam flow path. Such a configuration may be adopted.

  Among them, in the present embodiment, each of the plurality of grooves is curved so as to draw a concentric arc. However, the present invention is not limited to this, and the center position of the arc may be shifted. Further, the bending portion 7 is configured such that the radius of curvature becomes larger as the length of each flow channel becomes longer.

  When a plurality of curved flow paths are arranged in the vapor chamber, the flow path length becomes shorter toward the inside and the flow path length becomes longer toward the outside, so that the difference in flow resistance between the inside and the outside becomes large. This difference in flow resistance causes the balance of movement of the working fluid in the vapor chamber to be poor, and is one of the reasons why a sufficient heat transport ability cannot be exhibited. On the other hand, with the configuration having the radius of curvature as described above, it is possible to reduce the difference in flow resistance between the inside and the outside particularly in the steam flow path 4. As a result, the balance of movement of the working fluid is improved, and the heat transport capacity can be increased.

However, the curvature radius of the plurality of steam flow paths 4 in the curved portion 7 may be the same as in the example of FIG.

In the curved portion 7, the communication opening 14c and the communication opening 15c provided in the wall 14b and the wall 15b that separate the condensate flow path 3 and the vapor flow path 4 (see FIGS. 6 and 8B). , The pitch of which may be different from that of the linear portion 6. In this case, the pitch of the communication openings in the curved portion may be larger or smaller than the pitch of the curved portions in the straight portion. Regarding which form to use, the influence of the overall shape of the vapor chamber, the position of the heat source, and the like can be considered, and a form that can reduce the flow resistance can be comprehensively determined and adopted. Alternatively, regarding the curved portion 7, the communication opening 14c and the communication opening 15c may not be provided in the wall 14b and the wall 15b that partition the condensed liquid flow path 3 and the vapor flow path 4.
In a configuration in which the pitch of the communication opening of the curved portion is larger than the pitch of the communication opening of the straight portion, the working fluid flowing through the steam flow path 4 enters the communication opening 14c and the communication opening 15c in the bending portion 7. Can be suppressed. In the curved portion 7, a force acts on the working fluid moving through the steam flow path 4 to flow directly into the communication opening 14c and the communication opening 15c depending on the flow direction. Also, the flow resistance tends to increase due to the unevenness of the communication opening 14c and the communication opening 15c. On the other hand, the pitch of the communication opening 14c and the communication opening 15c in contact with the steam flow path 4 in the curved portion 7 is increased, and the communication opening 14c and the communication opening 15c in contact with the steam flow path 4 are eliminated. As a result, such an increase in flow resistance can be suppressed, the difference in flow resistance for each steam flow path 4 can be further reduced, the balance of movement of the working fluid can be improved, and the heat transport capacity can be increased. .
On the other hand, when the pitch of the communication opening of the curved portion is smaller than the pitch of the communication opening of the straight portion, the chance that the steam flowing through the steam flow channel (steam flow channel) strongly hits the wall surface in the bent portion increases. , Tends to condense. At this time, by making the pitch of the communication opening of the curved portion smaller than the pitch of the communication opening of the linear portion, the number of the communication openings is increased, and the condensate is smoothly supplied to the liquid flow channel (condensate flow channel). ), And it is possible to prevent the vapor passage from being closed by the condensate. As a result, an increase in flow resistance can be suppressed, the difference in flow resistance between the steam flow channels (steam flow channels) can be further reduced, the balance of movement of the working fluid can be improved, and the heat transport capability can be increased. There are cases.

  Also, instead of the pitch size, in the curved portion, the length of the wall (the size in the direction along the flow path) between the adjacent communication openings is larger than the length of the wall in the straight portion. May be configured to be larger or may be configured to be smaller. At this time, the length of the wall belonging to the curved portion does not need to be constant, and may be different for each wall. In this case, the magnitude relationship between the length of the wall of the curved portion and the length of the wall of the straight portion is based on the relationship between the average values of the lengths of the walls belonging to the respective portions.

On the other hand, as also shown in FIG. 1, the inner surface 10 a and the inner surface 20 a of the injection part 12 and the injection part 22 overlap so that they face each other. An injection flow path 5 is formed which is closed from the inner surface 10a of the injection part 12 of the first sheet 10 and communicates the outside with the hollow part (the condensate flow path 3 and the vapor flow path 4) between the main body 11 and the main body 21. ing.
However, after the working fluid is injected from the injection channel 5 into the closed space 2, the injection channel 5 is closed, so that the outside and the closed space 2 communicate with each other in the final form of the vapor chamber 1. Absent.

  A working fluid is sealed in the closed space 2 of the vapor chamber 1. Although the type of the working fluid is not particularly limited, a working fluid used in a normal vapor chamber, such as pure water, ethanol, methanol, or acetone, can be used.

  The above vapor chamber can be manufactured, for example, as follows.

  A sheet made of the material constituting the first sheet 10 and having the outer peripheral shape of the first sheet 10 and a sheet made of the material constituting the second sheet 20 and having the outer peripheral shape of the second sheet 20 are prepared. The liquid passage grooves 14a, the liquid passage grooves 15a, the steam passage grooves 16, the steam passage grooves 26, the steam passage communication grooves 17, and the steam passage communication grooves 27 described above for these sheets are half-etched. Form. Here, the half-etching refers to forming a groove or a dent by removing a material by etching halfway in the thickness direction without penetrating the thickness direction by etching.

Next, the etched sheet having the shape of the first sheet 10 and the etched sheet having the shape of the second sheet 20 are overlapped and temporarily fixed so that the inner surface 10a and the inner surface 20a face each other. The method of temporary fixing is not particularly limited, and examples thereof include resistance welding, ultrasonic welding, and bonding with an adhesive.
Then, diffusion bonding is performed after the temporary fixing, and these sheets are permanently bonded. In addition, you may join by brazing instead of diffusion joining. However, in the case of a vapor chamber having a small thickness as in the present embodiment, the flow path is narrow, and when brazing with a brazing material is used, there is a possibility that the brazing material may enter the flow path. As described above, since the strong capillary force acts on the flow path, the brazing filler metal may spread over a wide range of the flow path. From such a viewpoint, welding by welding, such as diffusion bonding or ultrasonic bonding, which does not cause such a problem is preferable.

  After the joining, a vacuum is drawn from the formed injection channel 5 to reduce the pressure in the hollow portion. Thereafter, a working fluid is injected from the injection channel 5 into the depressurized hollow portion, and the working fluid is introduced into the hollow portion. Then, the injection flow path 5 is closed by using or caulking the injection part 12 and the injection part 22 by laser melting. Thereby, the closed space 2 is formed, and the working fluid is stably held inside the closed space 2 to form the vapor chamber 1.

  Next, the operation when the vapor chamber 1 operates will be described. FIG. 22 schematically illustrates a state in which the vapor chamber 1 is disposed inside a portable terminal 40 which is an embodiment of an electronic device. Here, the vapor chamber 1 is indicated by a dotted line because it is disposed inside the housing 41 of the portable terminal 40. Such a portable terminal 40 includes a housing 41 containing various electronic components, and a display unit 42 exposed so that an image can be seen outside through an opening of the housing 41. As one of these electronic components, an electronic component 30 to be cooled by the vapor chamber 1 is arranged in a housing 41.

  The vapor chamber 1 is installed in a housing of a portable terminal or the like, and is attached to an electronic component 30 such as a CPU which is an object to be cooled. The electronic component 30 is attached directly to the outer surface 10b or the outer surface 20b of the vapor chamber 1 or via an adhesive, a sheet, a tape, or the like having high thermal conductivity.

FIG. 23 shows a diagram for explaining the behavior of the working fluid. For ease of explanation, this figure is a view from the same viewpoint as FIG. 21 and focuses on the condensate flow path 3 and the vapor flow path 4 formed in the closed space 2.
When the electronic component 30 generates heat, the heat is transmitted through the first sheet 10 by heat conduction, and the condensed liquid existing at a position close to the electronic component 30 in the closed space 2 receives the heat. The condensate that has received the heat absorbs the heat, evaporates and evaporates. Thereby, the electronic component 30 is cooled.

The vaporized working fluid turns into steam and moves through the steam channel 4. The movement of the vaporized working fluid may be caused by a movement such that the working fluid oscillates in the steam flow path 4 as shown by a solid straight arrow in FIG. 23, or an electronic component which is not shown but is a heat source without vibration. It may move in a direction away from 30.
At this time, the steam flow path 4 includes a curved portion of the bending portion 7, but since the bending portion 7 has the above-described configuration, the flow resistance is reduced even if the flow path length is different. The working fluid smoothly moves in the steam flow path 4 due to a good balance. Thereby, a high heat transport capability can be exhibited.
Then, at the time of the movement of the working fluid, the working fluid is cooled while the heat is sequentially taken by the first sheet 10 and the second sheet 20. The first sheet 10 and the second sheet 20, which have taken heat from the steam, transfer the heat to the outer surface 10b, the housing of the portable terminal device which has come into contact with the outer surface 20b, and finally the heat is released to the outside air. Then, the working fluid deprived of heat while moving in the steam flow path 4 is condensed and liquefied.

  Part of the condensate generated in the vapor flow path 4 moves to the condensate flow path 3 from the communication opening or the like. Since the condensate flow path 3 of this embodiment has the communication opening 14c and the communication opening 15c, the condensate is distributed to the plurality of condensate flow paths 3 through the communication opening 14c and the communication opening 15c. You.

  The condensed liquid that has entered the condensed liquid flow path 3 moves toward the electronic component 30 that is a heat source, as indicated by the dotted straight arrow in FIG. Then, it is vaporized again by the heat from the electronic component 30 which is a heat source, and the above process is repeated.

As described above, according to the vapor chamber 1, the movement of the working fluid in the steam flow path and the high capillary force in the condensate flow path make the movement of the working fluid smooth and favorable, and enhance the heat transport ability. Can be.
Further, by forming the flow path having the curved portion 7 in the vapor chamber 1, when the vapor chamber is arranged in the electronic device, there is a restriction on the arrangement, and when the vapor path cannot be formed only by a straight line. Even in this case, the heat generated from the heat source can be efficiently moved to the separated position.
The curved portion 7 is configured to reduce the flow resistance in the plurality of steam flow paths 4 as described above, or to reduce the difference in flow resistance as necessary, so that the working fluid is well-balanced. Can be moved, and the heat transport capacity can be increased.

  FIGS. 24 to 31 are diagrams illustrating a vapor chamber 201 according to the second embodiment. 24 is an external perspective view of the vapor chamber 201, and FIG. 25 is an exploded perspective view of the vapor chamber 201.

  The vapor chamber 201 has a first sheet 210, a second sheet 220, and a third sheet 230, as can be seen from FIGS. The first sheet 210, the second sheet 220, and the third sheet 230 are overlapped and joined (diffusion bonding, brazing, etc.), so that the first sheet 210 and the second sheet 220 Thus, a hollow portion surrounded by the first sheet 210, the second sheet 220, and the third sheet 230 is formed, and the working fluid is sealed in the hollow portion to form the closed space 202.

  In the present embodiment, the first sheet 210 is a sheet-like member as a whole. The first sheet 210 has a flat surface on both sides, and includes an inner surface 210a, an outer surface 210b opposite to the inner surface 210a, and a side surface 210c that forms a thickness across the inner surface 210a and the outer surface 210b. Prepare.

The first sheet 210 has a main body 211 and an injection section 212. The main body 211 is a sheet-like portion that forms a closed space in which the working fluid moves, and in the present embodiment, is a rectangular shape having a circular arc (so-called R) in plan view.
The injection part 212 is a part that injects the working fluid into the enclosed space formed by the first sheet 210, the second sheet 220, and the third sheet 230. It is a quadrangular sheet in a plan view that protrudes. In this embodiment, the injection portion 212 of the first sheet 210 has a flat surface on both the inner surface 210a side and the outer surface 210b side.

  In the present embodiment, the second sheet 220 is a sheet-like member as a whole. The second sheet 220 is formed of a flat surface on both sides, and includes an inner surface 220a, an outer surface 220b opposite to the inner surface 220a, and a side surface 220c that forms a thickness across the inner surface 220a and the outer surface 220b. Prepare.

  The second sheet 220 also has a main body 221 and an injection part 222.

  In the present embodiment, the third sheet 230 is a sheet that is sandwiched and overlapped between the inner surface 210a of the first sheet 210 and the inner surface 220a of the second sheet 220, and forms a structure for moving the working fluid to the main body 231. Have been. FIG. 26 shows a plan view of the third sheet 230. FIG. 26A is a diagram of a surface superimposed on the second sheet 220, and FIG. 26B is a diagram of a surface superimposed on the first sheet 210. FIG. 27 shows a section taken along the line XXIV-XXIV in FIG. 26 (a), and FIG. 28 shows a section taken along the line XXV-XXV in FIG. 26 (a). .

The third sheet 230 has a main body 231 and an injection portion 232. The main body 231 is a sheet-like portion that forms a closed space in which the working fluid moves, and in the present embodiment, has an L-shape having a curved portion in a plan view.
The injection part 232 is a part that injects the working fluid into the enclosed space formed by the first sheet 210, the second sheet 220, and the third sheet 230. It is a quadrangular sheet in a plan view that protrudes. The injection portion 232 has an injection groove 232 a formed on the side overlapping the first sheet 210. The injection groove 232a can be considered in the same manner as the above-described injection groove 22a.

  The main body 231 includes an outer joint 233, an outer liquid passage 234, an inner liquid passage 235, a steam passage slit 236, and a steam passage communication groove 237.

The outer peripheral joint portion 233 is a portion formed along the outer periphery of the main body 231. Then, one surface of the outer peripheral joint portion 233 overlaps and joins (diffusion bonding, brazing, etc.) the surface of the first sheet 210, and the other surface overlaps and joins (diffusion bonding, brazing) the surface of the second sheet 220. Attached, etc.). As a result, a hollow portion surrounded by the first sheet 210, the second sheet 220, and the third sheet 230 is formed, and the working fluid is sealed therein to form the closed space 202.
The outer peripheral joint 233 can be considered in the same manner as the outer peripheral joint 13 described above.

The outer liquid passage 234 functions as a liquid passage and constitutes a part of the condensed liquid passage 3 which is a passage through which the working fluid is condensed and liquefied. The outer peripheral liquid flow path portion 234 is formed along the inner side of the outer peripheral joint portion 233 of the main body 231, and is provided so as to be annular along the outer periphery of the closed space 202. A liquid flow channel groove 234a is formed on the surface of the outer liquid flow channel portion 234 facing the second sheet 220. In the present embodiment, the liquid flow channel 234a is provided only on the surface facing the second sheet 220, but in addition, the liquid flow channel is also provided on the surface facing the first sheet 210. You may.
The outer liquid passage portion 234 and the liquid passage groove 234a provided therein can be considered in the same manner as the outer liquid passage portion 14 and the liquid passage groove 14a described above.

  The inner liquid passage 235 also functions as a liquid passage, and is a part of the condensed liquid passage 3 that passes when the working fluid is condensed and liquefied. The inner liquid flow path portion 235 is formed so as to extend with a curved portion inside the ring of the annular outer liquid flow path portion 234 in the main body 231. A plurality (five in the present embodiment) of inner liquid flow paths 235 are arranged in a direction different from the extending direction, and are disposed between the vapor flow path slits 236.

A liquid passage groove 235a, which is a groove parallel to the direction in which the inner liquid passage portion 235 extends, is formed on a surface of the inner liquid passage portion 235 facing the second sheet 220. The inner liquid passage 235 and the liquid passage groove 235a can be considered in the same manner as the above-described inner liquid passage 15 and the liquid passage groove 15a.
In the present embodiment, the liquid flow channel groove 235a is provided only on the surface facing the second sheet 220, but in addition to this, the liquid flow channel groove is provided also on the surface facing the first sheet 210. You may.

The steam flow channel slit 236 is a portion where the vapor-like and condensed liquid working fluid moves, and is a slit that forms the steam flow channel 4. The vapor flow path slit 236 is formed by a slit having a curved portion, which is formed inside the ring of the annular outer liquid flow path section 234 in the main body 231. Specifically, the steam flow path slit 236 of the present embodiment is a slit formed between the adjacent inner liquid flow paths 235 and between the outer liquid flow path 234 and the inner liquid flow paths 235. Therefore, the steam passage slit 236 penetrates in the thickness direction (z direction) of the third sheet 230.
A plurality of (six in this embodiment) steam flow channel slits 236 are arranged in a direction different from the extending direction. Therefore, as can be seen from FIG. 27, the third sheet 230 has a shape in which the outer liquid passage 234, the inner liquid passage 235, and the vapor passage slit 236 are alternately repeated.

  Such a steam passage slit 236 can be considered in the same manner as the above-described embodiment of the steam passage 4 formed by combining the steam passage groove 16 and the steam passage groove 26.

  In the present embodiment, the cross-sectional shape of the steam flow passage slit 236 is a shape formed by overlapping a part of the elliptical arc, and the center in the thickness direction protrudes. Other forms such as a square such as a trapezoid, a triangle, a semicircle, a crescent, and a combination thereof may be used.

The steam flow path communication groove 237 is a groove that forms a flow path that connects the plurality of steam flow path slits 236. Thereby, the movement of the working fluid generated in the steam flow path in the direction in which the inner liquid flow path portion 235 extends can be balanced.
In addition, this makes it possible to equalize the working fluid in the steam flow path or to carry the steam to a wider range, and to efficiently use the condensed liquid flow path formed by the many liquid flow grooves 234a and 235a. You can do it.

  The vapor flow passage communication groove 237 of this embodiment is formed between both ends in the direction in which the inner liquid flow passage 235 extends and both ends in the direction in which the vapor flow passage slit 236 extends, and the outer peripheral liquid flow passage 234. I have. The shape of the steam flow path communication groove 237 is not particularly limited as long as the adjacent steam flow path slits 236 can be communicated, and the shape thereof is not particularly limited. Can be considered in the same manner as a flow path formed by superimposing.

  The third sheet 230 also has a straight section 238a, a straight section 238b, and a curved section 238c such that the vapor chamber 201 has a straight section and a curved section in the confined space 202 in the closed space 202. Is provided. The concepts of the straight portion and the curved portion are the same as those described so far.

  Such a third sheet 230 can be manufactured by etching performed separately for both surfaces, simultaneous etching from both surfaces, pressing, cutting, or the like.

  FIGS. 29 to 31 are diagrams illustrating a structure when the first sheet 210, the second sheet 220, and the third sheet 230 are combined to form the vapor chamber 201. FIG. 29 is a sectional view taken along the line XXVI-XXVI in FIG. 24, and FIG. 30 is an enlarged view of a part of FIG. FIG. 31 shows a section taken along the line XXVIII-XXVIII in FIG.

  As can be seen from FIG. 24 and FIGS. 29 to 31, the first sheet 210, the second sheet 220, and the third sheet 230 are arranged so as to be overlapped and joined to form the vapor chamber 201. . At this time, the second sheet is arranged such that the inner surface 210a of the first sheet 210 and one surface of the third sheet 230 (the surface on which the liquid flow grooves 234a and 235a are not disposed) face each other. The inner surface 220a of the second sheet 220 and the other surface of the third sheet 230 (the surface on the side where the liquid flow grooves 234a and 235a are disposed) face each other. Similarly, the injection part 212, the injection part 222, and the injection part 232 of each sheet are also overlapped.

  As a result, a closed space 202 surrounded by the first sheet 210, the second sheet 220, and the third sheet 230 is formed between the first sheet 210 and the second sheet 220. In this case, a condensate flow path 3 and a vapor flow path 4 are formed. Regarding the form of the condensate flow path 3 and the vapor flow path 4 in the closed space 202, the same concept as in the above-described vapor chamber 1 can be applied.

  In the above embodiment, the vapor chamber having a curved portion at the intersection where two straight portions intersect at 90 degrees and extend so as to form an L-shape has been described. However, the form of the curved portion is not limited to this, and the form of the curved portion described above can be applied to other forms. For example, an intersection where two straight portions extend in a direction intersecting a T-shape, an intersection where two straight portions extend in a direction intersecting a cross, and two straight lines at an acute angle (an angle smaller than 90 degrees). Intersecting portions when intersecting and extending to form a V-shape, and intersecting portions when two straight lines intersect at an obtuse angle (an angle greater than 90 degrees) and extend to form a V-shape. The above-described curved portion can be applied to the present invention.

REFERENCE SIGNS LIST 1 vapor chamber 2 closed space 3 condensed liquid flow path 4 vapor flow path 10 first sheet 11 main body 12 injection section 13 outer peripheral joining section 14 outer peripheral liquid flow path section 14a liquid flow path groove 14c communication opening 15 inner liquid flow path section 15a Liquid flow groove 15c Communication opening 16 Steam flow groove 17 Steam flow communication groove 20 Second sheet 21 Main body 22 Injection part 23 Outer peripheral joint part 24 Outer peripheral liquid flow part 25 Inner liquid flow part 26 Steam flow groove 27 Steam channel communication groove 230 Third sheet 236 Steam channel slit

Claims (6)

A vapor chamber in which a working fluid is sealed in a closed space,
In the closed space, a condensed liquid flow path, which is a flow path in which the working fluid moves in a condensed liquid state, and a flow path cross-sectional area larger than the condensed liquid flow path, and the working fluid is in a state of vapor and condensed liquid. And a plurality of steam flow paths moving by
A plurality of condensate flow paths and a plurality of vapor flow paths extending linearly,
Continuing with the linear portion, having a curved portion in which the direction in which the plurality of condensate flow paths and the plurality of vapor flow paths extend changes,
The vapor chamber, wherein the steam flow path in the curved portion is configured to have a larger flow path cross-sectional area than the steam flow path in the straight portion.   2. The vapor chamber according to claim 1, wherein a cross-sectional area of the steam flow path in the curved portion is constant in a direction in which the steam flow path extends. 3.   The vapor chamber according to claim 1, wherein the steam flow path in the curved portion is configured to be wider than the steam flow path in the straight portion.   The vapor chamber according to any one of claims 1 to 3, wherein the plurality of steam flow paths are connected.   The vapor chamber according to any one of claims 1 to 4, wherein the plurality of steam channels in the curved portion are configured to have different widths. A housing,
Electronic components arranged inside the housing,
An electronic apparatus comprising: the vapor chamber according to claim 1, which is disposed in contact with the electronic component directly or via another member.

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