JP7069678B2 - Vapor chamber - Google Patents

Description

The present invention relates to a vapor chamber that transports heat by refluxing a working fluid enclosed in a closed space with a phase change.

The amount of heat generated from a CPU (Central Processing Unit) provided in a personal computer and a portable terminal such as a mobile phone or a tablet terminal tends to increase due to an improvement in information processing capability, and cooling technology is important. Heat pipes are well known as a means for such cooling. This is to cool the heat source by transporting the heat in the heat source to another part and diffusing it by the working fluid enclosed in the pipe.

On the other hand, in recent years, the thinning has become remarkable especially in portable terminals and the like, and a cooling means thinner than the conventional heat pipe has been required. On the other hand, for example, a vapor chamber as described in Patent Document 1 has been proposed.

The vapor chamber is a device that develops the concept of heat transfer by heat pipe into a flat plate-shaped member. That is, in the vapor chamber, a working fluid is enclosed between the opposing flat plates, and the working fluid recirculates with a phase change to transport heat, and the heat in the heat source is transported and diffused to generate a heat source. Cooling.

More specifically, a steam flow path and a condensate flow path are provided between the facing flat plates of the vapor chamber, and the working fluid is sealed therein. When the vapor chamber is placed in the heat source, the working fluid receives heat from the heat source and evaporates near the heat source to become a gas (steam) and moves in the steam flow path. As a result, the heat from the heat source is smoothly transferred to a position away from the heat source, and as a result, the heat source is cooled.
The working fluid in the gaseous state that transports the heat from the heat source moves to a position away from the heat source, is cooled by being absorbed by the surroundings, condenses, and undergoes a phase change to the liquid state. The phase-changed working fluid in the liquid state passes through the flow path for the condensate, returns to the position of the heat source, receives heat from the heat source, evaporates, and changes to the gaseous state.
By the above circulation, the heat generated from the heat source is transported to a position away from the heat source and the heat source is cooled.

Patent Document 1 discloses a vapor chamber (sheet type heat pipe) in which such a steam flow path (steam passage) and a condensate flow path (wick) are formed having a predetermined pattern. There is. As a result, it is possible to achieve high heat transport capacity and thinning.

Japanese Unexamined Patent Publication No. 2016-50682

In recent years, there has been an increasing demand for improvement in cooling capacity (heat transport capacity), and it is necessary to increase heat transport capacity.

Therefore, it is an object of the present invention to provide a vapor chamber capable of increasing the heat transport capacity.

As a result of diligent studies, the inventor considers that more active circulation of the working fluid is important for enhancing the heat transport capacity, and the working fluid is particularly easy to condense and can smoothly enter the condensate flow path. The present invention was completed by taking inspiration from the structure and embodying it. Hereinafter, the present invention will be described. Here, for the sake of clarity, the reference numerals of the drawings are also described, but the present invention is not limited to this embodiment.

One aspect of the present invention has a first sheet (10) and a second sheet (20) laminated and joined to the first sheet, and is sealed between the first sheet and the second sheet. A space (2) is formed, and the working fluid is sealed in the space (1). In the closed space, the working fluid is condensed by superimposing the first sheet and the second sheet. A plurality of condensed liquid flow paths (3) through which the resulting liquid flows and a steam flow path (4) through which vapor vaporized working fluid flows are formed, and a part of the condensed liquid flow path is formed in the steam flow path. It is a vapor chamber.

The condensed liquid flow path (3) includes liquid flow path grooves (14a, 15a) which are a plurality of parallel grooves, and some of the liquid flow path grooves among the plurality of liquid flow path grooves are formed with the bottom of the groove. May be configured such that a portion on the opposite side is open and the opening is arranged so as to form a part of the steam flow path (4).

The liquid flow path grooves other than some of the liquid flow path grooves (14a, 15a) may be configured so that the openings are closed.

The plurality of liquid flow path grooves (14a, 15a) may be configured to communicate with the adjacent liquid flow path grooves by the openings (14c, 15c).

The plurality of condensate flow paths (3) include an annular condensate flow path extending along the outer periphery of the space (2) and a condensate flow path arranged inside the ring of the annular condensate flow path. It may be configured to be included.

The condensate flow path (3) is formed by superimposing the ridges (15, 15') provided on the first sheet and the ridges (25, 25') provided on the second sheet. A liquid flow path groove is formed in at least one of the ridges of the first sheet and the ridges of the second sheet, and one of the ridges of the first sheet and the ridges of the second sheet is longer than the other. It may be configured to be formed.

Of the ridges (15') of the first sheet and the ridges (25) of the second sheet, the ridges provided with the liquid flow path grooves may be configured to be long.

According to the vapor chamber of the present invention, since the condensed liquid easily enters the condensed liquid flow path, smooth reflux of the working fluid is promoted, and the heat transport capacity can be enhanced.

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. 2A is a perspective view of the first sheet 10, and FIG. 2B is a plan view of the first sheet 10. FIG. 3 is a cut surface of the first sheet 10. 4 (a) and 4 (b) are other cut surfaces of the first sheet 10. FIG. 5 is an enlarged view of a part of the outer peripheral liquid flow path portion 14 in a plan view. FIG. 6 is an enlarged view of a part of the outer peripheral liquid flow path portion 14 of another example in a plan view. FIG. 7 is an example in which the cross-sectional shape of the liquid flow path groove 14a is a semi-elliptical shape. FIG. 8A is a cut surface focusing on the inner liquid flow path portion 15, and FIG. 8B is an enlarged view of a part of the inner liquid flow path portion 15 in a plan view. FIG. 9 is an example in which the cross-sectional shape of the steam flow path groove 16 is semi-circular. 10 (a) is a perspective view of the second sheet 20, and FIG. 10 (b) is a plan view of the second sheet 20. 11 (a) and 11 (b) are cut surfaces of the second sheet 20. FIG. 12 is a cut surface of the vapor chamber 1. FIG. 13 is an enlarged view of a part of FIG. 12. 14 (a) and 14 (b) are views in which a part of FIG. 13 is further enlarged. FIG. 15 is another cut surface of the vapor chamber 1. FIG. 16 is a diagram illustrating a flow of working fluid. FIG. 17A is a plan view of the second sheet 20'of the vapor chamber 51, and FIG. 17B is a plan view of the first sheet 10 of the vapor chamber 51. FIG. 18A is a part of the cut surface of the vapor chamber 51, and FIG. 18B is the other part of the cut surface of the vapor chamber 51. 19 (a) is a plan view of the second sheet 20 of the vapor chamber 61, and FIG. 19 (b) is a plan view of the first sheet 10'of the vapor chamber 61. FIG. 20 is a part of the cut surface of the vapor chamber 61. 21 (a) is a plan view of the second sheet 20 ”of the vapor chamber 71, and FIG. 21 (b) is a plan view of the first sheet 10 of the vapor chamber 71. FIG. 22 is a part of the cut surface of the vapor chamber 71.

Hereinafter, the present invention will be described based on the embodiments shown in the drawings. However, the present invention is not limited to these forms. In the drawings shown below, the size and ratio of the members may be changed or exaggerated for the sake of clarity. In addition, for the sake of readability, illustrations of parts that are not necessary for explanation and reference numerals that are repeated may be omitted.

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

The vapor chamber 1 has a first sheet 10 and a second sheet 20 as can be seen from FIGS. 1 (a) and 1 (b). Then, as will be described later, the first sheet 10 and the second sheet 20 are overlapped and joined (diffusion joining, brazing, etc.) between the first sheet 10 and the second sheet 20. A closed space 2 is formed in the closed space 2 (see, for example, FIG. 12), and the working fluid is sealed in the closed space 2.

In this embodiment, the first sheet 10 is a sheet-like member as a whole. FIG. 2A shows a perspective view of the first sheet 10 as seen from the inner surface 10a side, and FIG. 2B shows a plan view of the first sheet 10 as seen from the inner surface 10a side. Further, FIG. 3 shows a cut surface of the first sheet 10 when cut in III-III in FIG. 2 (b).
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 connects the inner surface 10a and the outer surface 10b to form a thickness, and the working fluid returns to the inner surface 10a side. A pattern is formed for the flow path. As will be described later, the closed space 2 is formed by superimposing 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.

Such a first sheet 10 includes a main body 11 and an injection unit 12. The main body 11 has a sheet shape forming a portion where the working fluid returns, and in this embodiment, it is a rectangle having an arc (so-called R) formed at a corner in a plan view.
The injection portion 12 is a portion for injecting a working fluid into a closed space 2 (see, for example, FIG. 12) formed by the first sheet 10 and the second sheet 20, and in this embodiment, one side of the main body 11 is a rectangular shape in a plan view. It is a sheet-like rectangular shape in a plan view protruding from. In this embodiment, the injection portion 12 of the first sheet 10 has a flat surface on both the inner surface 10a side and the outer surface 10b side.

The thickness of such a first sheet 10 is not particularly limited, but is preferably 0.1 mm or more and 1.0 mm or less. This makes it possible to increase the number of situations in which it can be applied as a thin vapor chamber.
Further, the material constituting the first sheet 10 is not particularly limited, but a metal having high thermal conductivity is preferable. Examples thereof include copper and copper alloys.

A structure for refluxing the working fluid is formed on the inner surface 10a side of the main body 11. Specifically, the inner surface 10a side of the main body 11 is provided with an outer peripheral joint portion 13, an outer peripheral liquid flow path portion 14, an inner liquid flow path portion 15, a steam flow path groove 16, and a steam flow path communication groove 17. It is composed of.

The outer peripheral joint portion 13 is a flat surface formed along the outer periphery of the main body 11 on the inner surface 10a side of the main body 11. The outer peripheral joint portion 13 overlaps with the outer peripheral joint portion 23 of the second sheet 20 and is joined (diffusion joining, brazing, etc.) to form a closed space 2 between the first sheet 10 and the second sheet 20. The working fluid is sealed here.
The width of the outer peripheral joint portion 13 shown by A in FIGS. 2 (b) and 3 can be appropriately set as needed, but is preferably 0.8 mm or more and 3 mm or less. If this width is smaller than 0.8 mm, there is a risk that the joining area will be insufficient when the position shift occurs when the first sheet and the second sheet are joined. Further, if this width is larger than 3 mm, the internal volume of the closed space becomes small, and there is a possibility that the vapor flow path and the condensed liquid flow path cannot be sufficiently secured.

Further, in the outer peripheral joint portion 13, holes 13a penetrating in the thickness direction (z direction) are provided at the four corners of the main body 11. This hole functions as a positioning means when superimposing on the second sheet 20.

The outer peripheral liquid flow path portion 14 functions as a liquid flow path portion, and is a portion constituting a part of the condensed liquid flow path 3 through which the working fluid is condensed and liquefied. 4 (a) shows the portion of FIG. 3 indicated by the arrow IVa, and FIG. 4 (b) shows the cut surface of the portion cut by IVb-IVb in FIG. 2 (b). In each figure, the cross-sectional shape of the outer peripheral liquid flow path portion 14 is shown. Further, FIG. 5 shows an enlarged view of the outer peripheral liquid flow path portion 14 seen from the direction indicated by the arrow V in FIG. 4A in a plan view.

As can be seen from these figures, the outer peripheral liquid flow path portion 14 is formed along the inside of the outer peripheral joint portion 13 of the inner surface 10a of the main body 11 and is provided so as to form an annular shape along the outer periphery of the closed space 2. There is. Further, in the outer peripheral liquid flow path portion 14, a liquid flow path groove 14a which is a plurality of grooves extending in parallel with the outer peripheral direction of the main body 11 is formed, and the plurality of liquid flow path grooves 14a are formed by the liquid flow path groove 14a. They are arranged at predetermined intervals in a direction different from the extending direction. Therefore, as can be seen from FIGS. 4A and 4B, in the outer peripheral liquid flow path portion 14, the convex portion 14b between the liquid flow path groove 14a which is a concave portion and the liquid flow path groove 14a in the cross section thereof is formed. It is formed by repeating unevenness.
Here, since the liquid flow path groove 14 is a groove, an opening is provided in the bottom portion and a portion on the opposite side facing the bottom portion in the cross-sectional shape thereof.

Further, by providing the plurality of liquid flow path grooves 14a in this way, the depth and width of each liquid flow path groove 14a can be reduced, and the flow path cross-sectional area of the condensed liquid flow path 3 (see FIG. 14). Can be made smaller to take advantage of greater capillary force. On the other hand, by making the number of liquid flow path grooves 14a a plurality, the total flow path cross-sectional area of the condensed liquid flow path 3 is ensured to have an appropriate size, and the condensed liquid having a required flow rate can flow.

Further, in the outer peripheral liquid flow path portion 14, as can be seen from FIG. 5, adjacent liquid flow path grooves 14a communicate with each other by the liquid communication opening 14c at predetermined intervals. This promotes equalization of the amount of condensed liquid among the plurality of liquid flow path grooves 14a, allows the condensed liquid to flow efficiently, and enables smooth circulation of the working fluid.
In this embodiment, as shown in FIG. 5, the liquid communication opening so as to face the same position in the width direction (the direction orthogonal to the direction in which the liquid flow path groove 14a extends) across the groove of one liquid flow path groove 14a. The portion 14c is arranged. However, the present invention is not limited to this, and for example, as shown in FIG. 6, it differs in the width direction (the direction orthogonal to the direction in which the liquid flow path groove 14a extends) across the groove of one liquid flow path groove 14a. The liquid communication opening 14c may be arranged at the position. That is, the liquid communication openings 14c are arranged in a so-called staggered arrangement.

It is preferable that the outer peripheral liquid flow path portion 14 having the above configuration further has the following configuration.
Although the width of the outer peripheral liquid flow path portion 14 shown by B in FIGS. 2 (b), 3 and 4 (a) and 4 (b) can be appropriately set from the size of the entire vapor chamber and the like. , 0.3 mm or more and 2 mm or less is preferable. If this width is smaller than 0.3 mm, the amount of liquid refluxing to the outside may not be sufficient. Further, if this width exceeds 2 mm, there is a possibility that sufficient space for the inner liquid flow path and steam flow path cannot be obtained.
The width B is preferably larger than the width S (see FIG. 11) of the outer peripheral liquid flow path portion 24 of the second sheet. As a result, as will be described later, in at least a part of the outer peripheral liquid flow path portion 14, the opening of the liquid flow path groove 14a is arranged so as to form a part of the vapor flow path 4, from which the condensed liquid enters. Since it becomes easy, the condensed liquid can be recirculated more smoothly.

Regarding the liquid flow path groove 14a, the groove width shown by C in FIGS. 5 and 4A is preferably 20 μm or more and 200 μm or less. Further, the depth of the groove shown by D in FIGS. 4 (a) and 4 (b) is preferably 5 μm or more and 200 μm or less. As a result, the capillary force of the liquid flow path required for reflux can be sufficiently exerted.
From the viewpoint of exerting the capillary force of the flow path more strongly, the aspect ratio (aspect ratio) in the flow path cross section represented by C / D is preferably larger than 1.0 or smaller than 1.0. Among them, from the viewpoint of production, C> D is preferable, and the aspect ratio is preferably larger than 1.3.

In this embodiment, the cross-sectional shape of the liquid flow path groove 14a is rectangular, but the cross-sectional shape is not limited to this, and is not limited to a square, a quadrangle such as a trapezoid, a triangle, a semicircle, a semicircular shape, a semicircular bottom, and a semi-elliptical bottom. And so on. FIG. 7 shows an example in which the liquid flow path groove has a semi-elliptical shape. Due to this shape, it is possible to make a liquid flow path groove by etching.
Among these, a quadrangular shape is preferable because the surface tension tends to work easily due to the presence of the corners due to the inside corners, and the liquid tends to flow smoothly due to the capillary force.

Further, it is preferable that the pitch of the adjacent liquid flow path portions 14a in the plurality of liquid flow path grooves 14a is 40 μm or more and 600 μm or less. As a result, it is possible to increase the density of the condensed liquid flow path and prevent the flow path from being deformed and crushed at the time of joining or assembling.

With respect to the liquid communication opening 14c, the size of the opening along the direction in which the liquid flow path groove 14a shown in FIG. 5 E extends is preferably 20 μm or more and 180 μm or less.
Further, it is preferable that the pitch of the adjacent liquid communication openings 14c in the direction in which the liquid flow path groove 14a shown by F in FIG. 5 extends is 300 μm or more and 2700 μm or less.

Returning to FIGS. 2 and 3, the inner liquid flow path portion 15 will be described. The inner liquid flow path portion 15 also functions as a liquid flow path portion, and is a portion constituting a part of the condensed liquid flow path 3 through which the working fluid is condensed and liquefied. FIG. 8A shows the portion shown by VIIIa in FIG. This figure also shows the cross-sectional shape of the inner liquid flow path portion 15. Further, FIG. 8 (b) shows an enlarged view of the inner liquid flow path portion 15 seen from the direction indicated by the arrow VIIIb in FIG. 8 (a) in a plan view.

As can be seen from these figures, the inner liquid flow path portion 15 is formed inside the ring of the outer peripheral liquid flow path portion 14 which is an annular shape in the inner surface 10a of the main body 11. As can be seen from FIGS. 2 (a) and 2 (b), the inner liquid flow path portion 15 of the present embodiment is a rectangular protrusion in a plan view of the main body 11 extending in a direction parallel to the long side (x direction). , A plurality of (three in this embodiment) inner liquid flow path portions 15 are arranged at predetermined intervals in a direction parallel to the short side (y direction).
In each inner liquid flow path portion 15, a liquid flow path groove 15a which is a groove parallel to the direction in which the inner liquid flow path portion 15 extends is formed, and a plurality of liquid flow path grooves 15a are formed by the liquid flow path groove 15a. They are arranged at predetermined intervals in a direction different from the extending direction. Therefore, as can be seen from FIGS. 3 and 8 (a), in the inner liquid flow path portion 15, the convex portion 15b between the liquid flow path groove 15a which is a concave portion and the liquid flow path groove 15a in the cross section repeats unevenness. Is formed.
Here, since the liquid flow path groove 15a is a groove, an opening is provided in the bottom portion and a portion on the opposite side facing the bottom portion in the cross-sectional shape thereof.

By providing the plurality of liquid flow path grooves 15a in this way, the depth and width of each liquid flow path groove 15a can be reduced, and the flow path cross-sectional area of the condensed liquid flow path 3 (see FIG. 14) can be reduced. And a large capillary force can be utilized. On the other hand, by making the number of liquid flow path grooves 15a a plurality, the total flow path cross-sectional area of the condensed liquid flow path 3 is secured to have an appropriate size, and the condensed liquid having a required flow rate can flow.

Further, as can be seen from FIG. 8B, the adjacent liquid flow path grooves 15a communicate with each other by the liquid communication openings 15c at predetermined intervals. As a result, the equalization of the amount of the condensed liquid is promoted among the plurality of liquid flow path grooves 15a, and the condensed liquid can be efficiently flowed, so that the working fluid can be smoothly returned.
As for the communication opening 15c, similarly to the communication opening 14c, the communication openings may be arranged in a so-called staggered arrangement according to the example shown in FIG.

It is preferable that the inner liquid flow path portion 15 having the above configuration further has the following configuration.
The width of the inner liquid flow path portion 15 shown by G in FIGS. 2B, 3 and 8 is preferably 100 μm or more and 200 μm or less. The width G is preferably larger than the width T of the inner liquid flow path portion 25 of the second sheet 20 (see FIG. 11A). As a result, as will be described later, in at least a part of the inner liquid flow path portion 15, the opening of the liquid flow path groove 15a can be arranged so as to form a part of the steam flow path 4, and condensation is performed from here. Since the liquid easily enters, the condensed liquid can be recirculated more smoothly.
Further, the pitch of the plurality of inner liquid flow path portions 15 is preferably 200 μm or more and 4000 μm or less. As a result, the flow path resistance of the steam flow path can be sufficiently lowered, and the movement of the steam and the reflux of the condensed liquid can be performed in a well-balanced manner.

Regarding the liquid flow path groove 15a, the groove width shown by H in FIGS. 8 (a) and 8 (b) is preferably 20 μm or more and 200 μm or less. Further, the depth of the groove shown by J in FIG. 8A is preferably 5 μm or more and 200 μm or less. As a result, the capillary force of the condensate flow path required for reflux can be sufficiently exerted.
From the viewpoint of exerting the capillary force of the flow path more strongly, the aspect ratio (aspect ratio) in the flow path cross section represented by H / J is preferably larger than 1.0 or smaller than 1.0. Among them, from the viewpoint of production, H> J is preferable, and the aspect ratio is preferably larger than 1.3.

Further, in the present embodiment, the cross-sectional shape of the liquid flow path groove 15a is rectangular, but the cross-sectional shape is not limited to this, but is not limited to this, and is not limited to a square, a quadrangle such as a trapezoid, a triangle, a semicircle, a semicircular shape, a semicircular bottom, and a semi-elliptical bottom. And so on. It can also be made into a semi-elliptical shape according to the example of FIG. Due to this shape, it is possible to make a liquid flow path groove by etching.
Of these, a quadrangular shape is preferable because surface tension tends to work easily due to the presence of corners due to the inside corner, and the liquid tends to flow smoothly due to capillary force.

Further, it is preferable that the pitch of the adjacent liquid flow path grooves 15a in the plurality of liquid flow path grooves 15a is 40 μm or more and 600 μm or less. While increasing the density of the liquid flow path, it is possible to prevent the flow path from being crushed due to deformation during joining or assembly.

Regarding the liquid communication opening 15c, the size of the opening along the direction in which the liquid flow path groove 15a shown by K in FIG. 8B extends is preferably 20 μm or more and 180 μm or less.
Further, it is preferable that the pitch of the adjacent liquid communication openings 15c in the direction in which the liquid flow path groove 15a extends, which is shown by L in FIG. 8B, is 300 μm or more and 2700 μm or less.

Next, the steam flow path groove 16 will be described. The steam flow path groove 16 is a portion through which the vaporized steam by evaporating the working fluid passes, and constitutes a part of the steam flow path 4. FIG. 2B shows the shape of the steam flow path groove 16 in a plan view, and FIG. 3 shows the cross-sectional shape of the steam flow path groove 16.

As can be seen from these figures, the vapor flow path groove 16 is composed of a groove formed inside the ring of the annular outer peripheral liquid flow path portion 14 in the inner surface 10a of the main body 11. Specifically, the steam flow path groove 16 of the present embodiment is formed between the adjacent inner liquid flow path portions 15 and between the outer peripheral liquid flow path portion 14 and the inner liquid flow path portion 15, and is a plan view of the main body 11. It is a rectangular groove extending in a direction parallel to the long side (x direction). A plurality of (four in this embodiment) steam flow path grooves 16 are arranged in a direction parallel to the short side (y direction). Therefore, as can be seen from FIG. 3, in the first sheet 10, in the y direction, unevenness with the outer peripheral liquid flow path portion 14 and the inner liquid flow path portion 15 as ridges and the vapor flow path groove 16 as dents is repeated. It has a shape.
Here, since the steam flow path groove 16 is a groove, an opening is provided in the bottom portion and a portion on the opposite side facing the bottom portion in the cross-sectional shape thereof.

It is preferable that the steam flow path groove 16 having such a configuration further has the following configuration.
The width of the vapor flow path groove 16 shown by M in FIGS. 2 (b) and 3 is formed to be at least larger than the width C and the width H of the liquid flow path grooves 14a and 15a described above, and is 100 μm or more and 2000 μm or less. Is preferable. Further, the pitch of the steam flow path groove 16 is usually determined by the pitch of the inner liquid flow path portion 15.
On the other hand, the depth of the vapor flow path groove 16 shown by N in FIG. 3 is formed to be at least larger than the depth D and the depth J of the liquid flow path grooves 14a and 15a described above, and is 10 μm or more and 300 μm or less. preferable.
In this way, by making the flow path cross-sectional area of the steam flow path groove larger than that of the liquid flow path groove, it is possible to smoothly recirculate steam having a volume larger than that of the condensed liquid due to the nature of the working fluid.

In the present embodiment, the cross-sectional shape of the steam flow path groove 16 is rectangular, but the cross-sectional shape is not limited to this, and may be a quadrangle such as a square or a trapezoid, a triangle, a semicircle, a semi-elliptical shape, a circular bottom, a judgment circular shape, or the like. FIG. 9 shows an example in which the steam flow path groove 16 is semicircular. Due to this shape, it is possible to make a vapor flow path groove by etching.
Since the working fluid can be smoothly refluxed in the steam flow path by reducing the flow resistance of the steam, the shape of the cross section of the flow path can be determined from this viewpoint.

In this embodiment, an example in which one vapor flow path groove 16 is formed between adjacent inner liquid flow path portions 15 has been described, but the present invention is not limited to this, and two or more vapor flow path grooves 16 are formed between adjacent inner liquid flow path portions. The steam flow path grooves may be arranged side by side.

The steam flow path communication groove 17 is a groove that communicates a plurality of steam flow path grooves 16. As a result, the vapors of the plurality of steam flow path grooves 16 can be equalized, the vapors can be carried over a wider range, and many liquid flow path grooves 14a and 15a (condensate flow path 3) can be efficiently used. Therefore, it becomes possible to make the return of the working fluid smoother.

As can be seen from FIGS. 2 (a) and 2 (b), the steam flow path communication groove 17 of the present embodiment has both ends in the direction in which the inner liquid flow path portion 15 extends and both ends in the direction in which the steam flow path groove 16 extends. It is formed between the portion and the outer peripheral liquid flow path portion 14. FIG. 4B shows a cross section orthogonal to the communication direction of the steam flow path communication groove 17. Since the boundary between the steam flow path communication groove 17 and the steam flow path 16 does not necessarily form a boundary depending on the shape, the boundary is shown in FIGS. 2 (a) and 2 (b) for the sake of clarity. It is represented by a dotted line.

The steam flow path communication groove 17 may be formed so as to communicate the adjacent steam flow path grooves 16, and the shape thereof is not particularly limited, but for example, the following configuration can be provided. ..
The width of the steam flow path communication groove 17 shown by P in FIGS. 2 (b) and 4 (b) is preferably 100 μm or more and 1000 μm or less.
Further, the depth of the steam flow path communication groove 17 shown by Q in FIG. 4B is preferably 10 μm or more and 300 μm or less, and among them, it is the same as the depth N of the steam flow path groove 16. preferable. This facilitates manufacturing.

In this embodiment, the cross-sectional shape of the steam flow path communication groove 17 is rectangular, but the cross-sectional shape is not limited to this, but is not limited to a square, a quadrangle such as a trapezoid, a triangle, a semicircle, a semicircular shape, a semicircular bottom, a semi-elliptical bottom, etc. It may be. It can be made semi-circular according to the example of FIG. Due to this shape, it is possible to create a steam flow path communication groove by etching.
Since the steam flow path communication groove can make the working fluid flow smoothly by reducing the flow resistance of the steam, the shape of the flow path cross section can be determined from such a viewpoint.

Next, the second sheet 20 will be described. In this embodiment, the second sheet 20 is also a sheet-like member as a whole. FIG. 10A shows a perspective view of the second sheet 20 as seen from the inner surface 20a side, and FIG. 10B shows a plan view of the second sheet 20 as seen from the inner surface 20a side. Further, FIG. 11A shows the cut surface of the second sheet 20 when cut by XIa-XIa in FIG. 10B. Further, FIG. 11 (b) shows the cut surface of the second sheet 20 when cut by XIb-XIb in FIG. 10 (b).
The second sheet 20 includes an inner surface 20a, an outer surface 20b opposite to the inner surface 20a, and a side surface 20c connecting the inner surface 20a and the outer surface 20b to form a thickness, and a pattern in which the working fluid returns to the inner surface 20a side. Is formed. As will be described later, a closed space is formed by superimposing the inner surface 20a of the second sheet 20 and the inner surface 10a of the first sheet 10 so as to face each other.

Such a second sheet 20 includes a main body 21 and an injection unit 22. The main body 21 is a sheet-like portion forming a portion where the working fluid returns, and in this embodiment, it is a rectangle having an arc (so-called R) formed at a corner in a plan view.
The injection unit 22 is a portion for injecting the working fluid into the closed space 2 (see FIG. 12) formed by the first sheet 10 and the second sheet 20, and in this embodiment, one side of the main body 21 which is a rectangular shape in a plan view. It is a sheet-like rectangular shape in a plan view protruding from. 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 communicates from the side surface 20c of the second sheet 20 to the inside of the main body 21 (a portion that should be the closed space 2). ing.
The thickness of the second sheet 20 and the constituent materials can be considered in the same manner as the first sheet 10.

A structure for refluxing the working fluid is formed on the inner surface 20a side of the main body 21. Specifically, the inner surface 10a side of the main body 21 is provided with an outer peripheral joint portion 23, an outer peripheral liquid flow path portion 24, an inner liquid flow path portion 25, a steam flow path groove 26, and a steam flow path communication groove 27. ing.

The outer peripheral joint portion 23 is a flat surface formed along the outer periphery of the main body 21 on the inner surface 20a side of the main body 21. The outer peripheral joint portion 23 overlaps with the outer peripheral joint portion 13 of the first sheet 10 and is joined (diffusion joining, brazing, etc.) to form a closed space 2 between the first sheet 10 and the second sheet 20. Then, the working fluid is sealed here.
It is preferable that the width of the outer peripheral joint portion 23 shown in FIGS. 10 (b), 11 (a), and 11 (b) is the same as the width A of the outer peripheral joint portion 13 of the main body 11 described above.

Further, in the outer peripheral joint portion 23, holes 23a penetrating in the thickness direction (z direction) are provided at the four corners of the main body 21. The hole 23a functions as a positioning means when superimposing on the first sheet 10.

The outer peripheral liquid flow path portion 24 is a liquid flow path portion, and is a portion constituting a part of the condensed liquid flow path 3 through which the working fluid is condensed and liquefied.

The outer peripheral liquid flow path portion 24 is formed along the inside of the outer peripheral joint portion 23 in the inner surface 20a 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, the outer peripheral liquid flow path portion 24 of the second sheet 20 is a flat surface and is flush with the outer peripheral joint portion 23 as can be seen from FIGS. 11 (a) and 11 (b). As a result, the opening of at least a part of the liquid flow path grooves 14a of the plurality of liquid flow path grooves 14a of the first sheet 10 is closed to form the condensed liquid flow path 3. A detailed aspect regarding the combination of the first sheet 10 and the second sheet 20 will be described later.
As described above, in the second sheet 20, since the outer peripheral joint portion 23 and the outer peripheral liquid flow path portion 24 are flush flat surfaces, there is no structurally distinguishing boundary line between them. However, for the sake of clarity, the boundary between the two is represented by a dotted line in FIG. 10 (b).

The outer peripheral liquid flow path portion 24 preferably has the following configuration.
The width of the outer peripheral liquid flow path portion 24 shown by S in FIGS. 10 (b), 11 (a), and 11 (b) is smaller than the width B of the outer peripheral liquid flow path portion 14 of the first sheet 10. Is preferable. As a result, as will be described later, in at least a part of the outer peripheral liquid flow path portion 14, the opening of the liquid flow path groove 14a is opened without being closed by the outer peripheral liquid flow path portion 24, and the condensed liquid easily enters from here. Therefore, the condensate can be recirculated more smoothly.
From this point of view, the size of the width S is B / 2 ≦ S ≦ B ₁ in relation to the width B of the outer peripheral liquid flow path portion 14 of the first sheet 10 shown in FIG. 4 (a). Is preferable. Here, B ₁ is located at a position that is half the width of the liquid flow path groove 14a on the steam flow path groove 16 side among the liquid flow path grooves 14a arranged in the outer peripheral liquid flow path portion 14, and the outer peripheral liquid flow path. It means the distance between the outer peripheral joint portion 13 side end portion of the portion 14 and the outer peripheral joint portion 13. If the width S is smaller than B / 2, the number of liquid flow path grooves 14a that can close the opening is reduced, so that the capillary force in the condensed liquid flow path 3 may be insufficient. Further, when the width S is larger than B ₁ , the opening of the liquid flow path groove 14a exposed to the steam flow path 4 is reduced, and there is a possibility that the inflow of the condensed liquid into the liquid flow path groove 14a is insufficient.

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

As can be seen from FIGS. 10 (a), 10 (b), 11 (a), and 11 (b), the inner liquid flow path portion 25 is the outer peripheral liquid flow path portion 24 of the inner surface 20a of the main body 21. It is formed more inward. The inner liquid flow path portion 25 of the present embodiment is a rectangular shape in a plan view of the main body 21 and is a ridge extending in a direction parallel to the long side (x direction), and a plurality of (three in this embodiment) inner liquid flow path portions 25. Are arranged at predetermined intervals in a direction parallel to the same short side (y direction).
In this embodiment, each inner liquid flow path portion 25 has a flat surface formed on the inner surface 20a side of the inner liquid flow path portion 25. As a result, the opening of at least a part of the liquid flow path grooves 15a of the plurality of liquid flow path grooves 15a of the first sheet 10 is closed to form the condensed liquid flow path 3.

It is preferable that the width of the inner liquid flow path portion 25 shown by T in FIGS. 10 (b) and 11 (a) is smaller than the width G of the inner liquid flow path portion 15 of the first sheet 10. As a result, as will be described later, in at least a part of the inner liquid flow path portion 15, the opening of the liquid flow path groove 15a is not closed by the inner liquid flow path portion 25, and the condensed liquid easily enters from here. The condensed liquid can be smoothly refluxed.
From this point of view, the size of the width T may be G ₂ ≤ T ≤ G ₁ in relation to the width G of the inner liquid flow path portion 15 of the first sheet 10 shown in FIG. 8 (a). preferable.
Here, as shown in FIG. 8A, G ₁ is a position that is half the width of the first liquid flow path groove 15a from the steam flow path groove 16 side among the plurality of liquid flow path grooves 15a. The distance between them.
Further, as shown in FIG. 8A, G2 is the end of the _second liquid flow path groove 15a from the steam flow path groove 16 side among the plurality of liquid flow path grooves 15a on the steam flow path groove 16 side. The distance between departments.
If the width T is smaller than G ₂ , the number of liquid flow path grooves 15a that can close the opening is reduced, so that the capillary force in the condensed liquid flow path 3 may be insufficient. Further, when the width T is larger than G ₁ , the opening of the liquid flow path groove 15a exposed to the steam flow path 4 is reduced, and there is a possibility that the inflow of the condensed liquid into the liquid flow path groove 15a is insufficient.

Next, the steam flow path groove 26 will be described. The steam flow path groove 26 is a portion through which the vaporized steam by evaporating the working fluid passes, and constitutes a part of the steam flow path 4. FIG. 10B shows the shape of the steam flow path groove 26 in a plan view, and FIG. 11A shows the cross-sectional shape of the steam flow path groove 26.

As can be seen from these figures, the vapor flow path groove 26 is composed of a groove formed inside the ring of the outer peripheral liquid flow path portion 24, which is an annular shape, in the inner surface 20a of the main body 21. Specifically, the steam flow path groove 26 of the present embodiment is formed between the adjacent inner liquid flow path portions 25 and between the outer peripheral liquid flow path portion 24 and the inner liquid flow path portion 25, and is a plan view of the main body 21. It is a rectangular groove extending in a direction parallel to the long side (x direction). A plurality of (four in this embodiment) steam flow path grooves 26 are arranged in a direction parallel to the short side (y direction). Therefore, as can be seen from FIG. 11A, the second sheet 20 is formed with ridges having the outer peripheral liquid flow path portion 24 and the inner liquid flow path portion 25 convex in the y direction, and the steam flow path groove 26 is formed. A concave groove is formed, and the shape is such that these irregularities are repeated.
Here, since the steam flow path groove 26 is a groove, an opening is provided in the bottom portion and a portion on the opposite side facing the bottom portion in the cross-sectional shape thereof.

It is preferable that the steam flow path groove 26 is arranged at a position where it overlaps with the steam flow path groove 16 of the first sheet 10 in the thickness direction when combined with the first sheet 10. As a result, the steam flow path 4 can be formed by the steam flow path groove 16 and the steam flow path groove 26.

It is preferable that the width of the steam flow path groove 26 shown by U in FIGS. 10 (b) and 11 (a) is larger than the width M of the steam flow path groove 16 of the first sheet 10. As a result, as will be described later, in at least a part of the inner liquid flow path portion 15 of the first sheet 10, the opening of the liquid flow path groove 15a is exposed to the steam flow path 4, so that the condensed liquid can easily enter. The condensate can be recirculated more smoothly.
On the other hand, the depth of the steam flow path groove 26 shown by V in FIG. 11A is preferably 10 μm or more and 300 μm or less.

In the present embodiment, the cross-sectional shape of the steam flow path groove 26 is rectangular, but it may be a square, a quadrangle such as a trapezoid, a triangle, a semicircle, a semicircular shape, a semicircular bottom, a semi-elliptical bottom, or the like. It can be made semi-circular according to the example of FIG. Due to this shape, it is possible to make a vapor flow path groove by etching.
Since the working fluid can be smoothly circulated in the steam flow path by reducing the flow resistance of the steam, the shape of the cross section of the flow path can be determined from this viewpoint.

In this embodiment, an example in which one vapor flow path groove 26 is formed between adjacent inner liquid flow path portions 25 has been described, but the present invention is not limited to this, and two or more vapor flow path grooves 26 or more are formed between adjacent inner liquid flow path portions. The steam flow path grooves may be arranged side by side.

The steam flow path communication groove 27 is a groove that communicates a plurality of steam flow path grooves 26, and constitutes a part of the steam flow path 4. As a result, the vapors of the plurality of steam flow paths 4 can be equalized, the steam can be carried over a wider range, and many condensate flow paths 3 can be efficiently used. It becomes possible to make the reflux smoother.

As can be seen from FIGS. 10 (b) and 11 (b), the steam flow path communication groove 27 of the present embodiment has both ends in the direction in which the inner liquid flow path portion 25 extends and both ends in the direction in which the steam flow path groove 26 extends. It is formed between the portion and the outer peripheral liquid flow path portion 24. Further, FIG. 11B shows a cross section orthogonal to the communication direction of the steam flow path communication groove 27.

The width of the steam flow path communication groove 27 shown by W in FIGS. 10 (b) and 11 (b) is preferably larger than the width P of the steam flow path communication groove 17 of the first sheet 10, and is 50 μm or more and 200 μm. It is more preferable that the width P is larger than the width P in the following range. As a result, as will be described later, in at least a part of the outer peripheral liquid flow path portion 14 of the first sheet 10, the opening of the liquid flow path groove 14a is arranged so as to form a part of the steam flow path 4. The condensed liquid can easily enter, and the condensed liquid can be recirculated more smoothly.
On the other hand, the depth of the steam flow path communication groove 27 shown by X in FIG. 11B is preferably 10 μm or more and 300 μm or less.

In this embodiment, the cross-sectional shape of the steam flow path communication groove 27 is rectangular, but the cross-sectional shape is not limited to this, but is limited to squares, trapezoids and other quadrangles, triangles, semicircles, semi-elliptical shapes, semi-circular bottoms, semi-elliptical bottoms and the like. There may be. It can be made semi-circular according to the example of FIG. Due to this shape, it is possible to create a steam flow path communication groove by etching.
Since the steam flow path can be smoothly recirculated by reducing the flow resistance of the steam, the shape of the cross section of the flow path can be determined from such a viewpoint.

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 explanation, the arrangement, size, shape, etc. of each configuration of the first sheet 10 and the second sheet 20 are further understood.
FIG. 12 shows a cut surface obtained by cutting the vapor chamber 1 in the thickness direction along the y direction shown by XII-XII in FIG. 1 (a). This figure is a combination of the figure shown in FIG. 3 on the first sheet 10 and the figure shown in FIG. 11 (a) on the second sheet 20 to show the cut surface of the vapor chamber 1 at this site. be.
FIG. 13 is an enlarged view of the portion shown by XIII in FIG. 12, and FIG. 14 (a) further enlarges the portion of FIG. 13 in which the inner liquid flow path portion 15 and the inner liquid flow path portion 25 overlap. FIG. 14 (b) shows a further enlarged view of the portion of FIG. 13 where the outer peripheral liquid flow path portion 14 and the outer peripheral liquid flow path portion 24 overlap.
FIG. 15 shows a cut surface cut in the thickness direction of the vapor chamber 1 along the x direction shown by XV-XV in FIG. 1 (a). In this figure, the figure shown in FIG. 4 (b) of the first sheet 10 and the figure shown in FIG. 11 (b) of the second sheet 20 are combined to show the cut surface of the vapor chamber 1 at this site. It was done.

As can be seen from FIGS. 1 (a), 1 (b), and FIGS. 12 to 15, the first sheet 10 and the second sheet 20 are arranged and joined so as to be overlapped with each other 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, and the main body 11 of the first sheet 10 and the main body 21 of the second sheet overlap each other, and the first sheet 10 The injection portion 12 and the injection portion 21 of the second sheet 20 overlap each other. In the present embodiment, the relative positional relationship between the first sheet 10 and the second sheet 20 is configured to be appropriate by aligning the holes 13a of the first sheet 10 and the holes 23a of the second sheet 20. ing.

With such a laminated body of the first sheet 10 and the second sheet 20, each configuration provided in the main body 11 and the main body 21 is arranged so as to appear in FIGS. 12 to 15. Specifically, it is as follows.

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

The outer peripheral liquid flow path portion 14 of the first sheet 10 and the outer peripheral liquid flow path portion 24 of the second sheet 20 are arranged so as to overlap each other. As a result, the liquid flow path 3a through which the working fluid is condensed and liquefied is formed by the liquid flow path groove 14a of the outer peripheral liquid flow path portion 14 and the outer peripheral liquid flow path portion 24.
Here, as can be seen from FIGS. 12 to 15, in this embodiment, the width B of the outer peripheral liquid flow path portion 14 of the first sheet 10 is larger than the width S of the outer peripheral liquid flow path portion 24 of the second sheet 20. Is also formed large. As a result, the outer peripheral liquid flow path portion 24 of the second sheet 20 does not overlap with the liquid flow path groove 14a on the steam flow path 4 side among the plurality of liquid flow path grooves 14a provided in the outer peripheral liquid flow path portion 14. Therefore, the opening is not closed. Therefore, in this portion, an opening facing the second sheet 20 is formed as shown by α in FIGS. 13 to 15, and the opening forms a part of the steam flow path 4, and the steam flow. It communicates with road 4.
By arranging a part of the condensed liquid flow path in the steam flow path in this way, the condensed liquid easily flows into the liquid flow path groove 14a which is the condensed liquid flow path, and the return of the working fluid becomes smoother. Become.

On the other hand, of the liquid flow path groove 14a, the groove whose opening is closed by the outer peripheral liquid flow path portion 24 has walls on all four sides in the cross section, so that the capillary force works strongly and smooth flow of the liquid is performed. ..

The inner liquid flow path portion 15 which is a ridge of the first sheet 10 and the inner liquid flow path portion 25 which is a ridge of the second sheet 20 are arranged so as to overlap each other. As a result, the liquid flow path 3 a through which the condensed liquid flows is formed by the liquid flow path groove 15a and the inner liquid flow path portion 25 of the inner liquid flow path portion 15.
Here, as can be seen from FIGS. 12 to 15, in this embodiment, the width G of the inner liquid flow path portion 15 of the first sheet 10 is larger than the width T of the inner liquid flow path portion 25 of the second sheet 20. Is also formed large. As a result, the inner liquid flow path portion 25 of the second sheet 20 does not overlap with the liquid flow path groove 15a on the steam flow path 4 side among the plurality of liquid flow path grooves 15a provided in the inner liquid flow path portion 15. Therefore, the opening is not closed. Therefore, in this portion, an opening facing the second sheet 20 is formed as shown by β in FIGS. 13 to 15, and the opening forms a part of the steam flow path 4, and the steam flow. It communicates with road 4.
By arranging at least a part of the condensed liquid flow path in the steam flow path in this way, the condensed liquid easily flows into the liquid flow path groove 15a which is the condensed liquid flow path, and the return of the working fluid becomes smoother. become.

On the other hand, of the liquid flow path grooves 15a, the groove whose opening is closed by the inner liquid flow path portion 25 has walls on all four sides in the cross section, so that the capillary force works strongly and smooth flow of the liquid is performed. ..

The opening of the steam flow path groove 16 of the first sheet 10 and the opening of the steam flow path groove 26 of the second sheet 20 are overlapped so as to face each other to form a flow path, which becomes the steam flow path 4 through which steam flows.
Here, as can be seen from FIGS. 12 to 14, in this embodiment, the width U of the steam flow path groove 26 of the second sheet 20 is larger than the width M of the steam flow path groove 16 of the first sheet 10. It is formed. As a result, at least a part of the condensed liquid flow path is arranged in the steam flow path as described above, and the condensed liquid flows into the liquid flow path groove 15a from the opening of the liquid flow path groove 15a which is the condensed liquid flow path. The return of the working fluid becomes smoother.

As can be seen from FIG. 15, 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 are overlapped to form a flow path, and this forms a flow path. It becomes the steam flow path 4.
Here, in the present embodiment, the width W of the steam flow path communication groove 27 of the second sheet 20 is formed larger than the width P of the steam flow path communication groove 17 of the first sheet 10. As a result, as described above, at least a part of the condensed liquid flow path is arranged in the steam flow path, and the liquid flow path grooves 14a, 15a are opened through the openings of the liquid flow path grooves 14a, 15a in which the condensed liquid is the condensed liquid flow path. It flows in and the working fluid recirculates more smoothly.
As shown in FIG. 15, in the steam flow path 4 with the steam flow path communication portions 17 and 27, the liquid flow path groove 15a of the inner liquid flow path portion 15 at the longitudinal end portion of the inner liquid flow path portions 15 and 25. The opening of the liquid flow path portion 15a is exposed to the steam flow path 4, and the opening of the liquid flow path portion 15a appears at this portion so as to face the second sheet 20 as shown by γ in FIG. 15, and communicates with the steam flow path 4. There is. This also causes at least a part of the condensed liquid flow path to be arranged in the steam flow path, so that the condensed liquid easily flows into the liquid flow path groove 15a which is the condensed liquid flow path 3, and the working fluid returns. It will be smoother.

On the other hand, as shown in FIG. 1, the injection portions 12 and 22 are overlapped so that the inner surfaces 10a and 20a face each other, and the opening on the side opposite to the bottom of the injection groove 22a of the second sheet 20 is the first sheet. An injection flow path 5 is formed which is closed from the inner surface 10a of the injection portion 12 of 10 and communicates with the outside and the closed space 2 (condensate flow path 3 and steam flow path 4) between the main bodies 11 and 21.
However, since the injection flow path 5 is closed after the working fluid is injected into the closed space 2 from the injection flow path 5, the outside and the closed space 2 communicate with each other in the final form of the vapor chamber 1. not.

The working fluid is sealed in the closed space 2 of the vapor chamber 1. The type of working fluid is not particularly limited, but working fluids used in ordinary vapor chambers such as pure water, ethanol, methanol, and acetone can be used.

The vapor chamber as described above can be manufactured, for example, as follows.
Liquid flow path grooves 14a and 15a, vapor flow path grooves 16 and 26, and vapor flow path communication grooves 17 and 27 are formed by half etching on the metal sheets having the outer peripheral shapes of the first sheet 10 and the second sheet 20. do.
Next, the inner surfaces 10a and 20a of the first sheet 10 and the second sheet 20 are overlapped so as to face each other, positioned using the holes 13a and 23a as the positioning means, and temporarily fixed. The method of temporary fixing is not particularly limited, and examples thereof include resistance welding, ultrasonic welding, and adhesion with an adhesive.
Then, after temporary fixing, diffusion bonding is performed to permanently bond the first sheet 10 and the second sheet 20. In addition, you may join by brazing instead of diffusion joining.

After joining, vacuuming is performed from the formed injection flow path 5 to reduce the pressure in the closed space 2. After that, the working fluid is injected into the depressurized closed space 2 from the injection flow path 5, and the working fluid is put into the closed space 2. Then, the injection flow path 5 is closed by using melting by a laser or caulking the injection portions 12 and 22. As a result, the working fluid is stably held inside the closed space 2.

Next, the operation of the vapor chamber 1 will be described.
The vapor chamber 1 is installed in a housing of a portable terminal or the like, and is attached to an object to be cooled such as a CPU. The object to be cooled 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. The position of the outer surface 10a and 10b to which the object to be cooled is attached is not particularly limited, and is appropriately set depending on the arrangement of other members in the portable terminal or the like. In this embodiment, as shown by the dotted line in FIG. 1A, the cooling object 30 which is a heat source to be cooled is arranged at the center of the outer surface 10a of the first sheet 10 in the xy direction. Therefore, in FIG. 1A, the cooling object 30 is a blind spot and cannot be seen, so it is represented by a dotted line.
FIG. 16 shows a diagram illustrating the flow of the working fluid. For the sake of ease of explanation, the second sheet 20 is omitted in this figure, and the inner surface 10a of the first sheet 10 is displayed so as to be visible.

When the object to be cooled 30 generates heat, the heat is transferred through the first sheet 10 by heat conduction, and the condensate existing at a position close to the object to be cooled 30 in the enclosed space 2 receives heat. The condensate that receives this heat absorbs the heat, evaporates, and vaporizes. As a result, the object to be cooled 30 is cooled.

The vaporized working fluid becomes steam and flows in the steam flow path 4 as shown by the straight line arrow in FIG. 16 and moves. Since this flow is generated in the direction away from the cooling object 30, the steam moves in the direction away from the cooling object 30.
The steam in the steam flow path 4 separates from the cooling object 30 which is a heat source, moves to the outer peripheral portion of the vapor chamber 1 having a relatively low temperature, and during the movement, heats the first sheet 10 and the second sheet 20 in sequence. It is cooled while being robbed. The first sheet 10 and the second sheet 20 that have taken heat from the steam transfer heat to the housing of the portable terminal that is in contact with the outer surfaces 10b and 20b, and finally the heat is released to the outside air.

The working fluid that has been deprived of heat while moving through the steam flow path 4 condenses and liquefies. This condensed liquid adheres to the wall surface of the steam flow path 4. On the other hand, since steam is continuously flowing in the steam flow path 4, the condensed liquid moves to the condensed liquid flow path 3 so as to be pushed by the steam as shown by the arrow _Z2 in FIGS. 13 and 15. .. Since the condensed liquid flow path 3 of the present embodiment includes the liquid communication openings 14c and 15c as shown in FIGS. 5 and 8 (b), the condensed liquid passes through the liquid communication openings 14c and 15c. It is distributed to a plurality of condensate flow paths 3.
Further, in the vapor chamber 1 of the present embodiment, since a part of the condensed liquid flow path ₃ is provided in the steam flow path 4, the condensed liquid is in the thickness direction as shown by the arrow Z3 in FIGS. 13 and 15. It moves to the condensate flow path 3 so as to be pushed in by steam. Therefore, the condensed liquid easily enters the condensed liquid flow path 3, and the working fluid can be smoothly returned.

The condensed liquid that has entered the condensed liquid flow path 3 approaches the cooling object 30 that is a heat source as shown by the dotted straight line arrow in FIG. 16 due to the capillary phenomenon caused by the condensed liquid flow path 3 and the pressing from the steam. Move like.
In particular, for some of the condensed liquid flow paths 3 that are not arranged in the steam flow path 4, the openings of the liquid flow path grooves 14a and 15a are blocked by the second sheet 20, so that all four sides of the condensed liquid flow path 3 are walls in the cross section. It becomes possible to increase the capillary force. This enables smoother movement of the condensed liquid.
Then, it is vaporized again by the heat from the cooling object 30 which is a heat source, and the above is repeated.

As described above, according to the vapor chamber 1, the inflow of the condensed liquid into the condensed liquid flow path is smoothly performed, so that the return of the working fluid is good and the heat transport amount can be increased.

Hereinafter, other forms of the vapor chamber will be described. In each figure showing other forms, the same reference numerals are given to those that can be configured with the same idea as the configuration described in the first embodiment, and the description thereof will be omitted.

17 and 18 show diagrams illustrating the vapor chamber 51 according to the second embodiment. FIG. 17A shows a view of the second sheet 20'viewed from the inner surface side, and FIG. 17B shows a view of the first sheet 10 seen from the inner surface side. Further, FIG. 18 (a) is a cut surface of the vapor chamber 51 at the site shown by XVIIIa-XVIIIa in FIGS. 17 (a) and 17 (b). 18 (b) is a cut surface of the vapor chamber 51 at the site shown by XVIIIb-XVIIIb in FIGS. 17 (a) and 17 (b).

In the vapor chamber 51 of the present embodiment, the first sheet 10 is the same as the vapor chamber 1.
Further, in the second sheet 20', a part (two in this embodiment) of the inner liquid flow path portion 25'is formed longer than the inner liquid flow path portion of the first sheet. Then, the end portion reaches the outer peripheral liquid flow path portion 24.
According to this, as can be seen by comparing FIG. 18 (b) with FIG. 18 (a), a part of the vapor flow path is narrowed by the inner liquid flow path portion 25', and the condensed liquid flow is formed in this portion. There will be no part where the path will be placed in the steam flow path.
However, according to this, since there is no steam flow path communication groove in this portion, the strength of the second sheet 20'can be increased, and the strength of the vapor chamber as a whole can also be increased. In particular, the vapor chamber is easily deformed because it is evacuated or joined in the manufacturing process. On the other hand, in the vapor chamber 51, deformation can be suppressed by forming a structure like the inner liquid flow path portion 25'at least in a part thereof.

19 and 20 show diagrams illustrating the vapor chamber 61 according to the third embodiment. FIG. 19 (a) shows a view of the second sheet 20 as viewed from the inner surface side, and FIG. 19 (b) shows a view of the first sheet 10'as viewed from the inner surface. 20 is a cut surface of the vapor chamber 61 at the portion shown by XX-XX in FIGS. 19 (a) and 19 (b).

In the vapor chamber 61 of the present embodiment, the second sheet 20 is the same as the vapor chamber 1.
Further, in the first sheet 10', the inner liquid flow path portion 15'is formed longer than the inner liquid flow path portion 25 of the second sheet 20. Then, the vapor flow path communication groove is not formed, and the end portion reaches the outer peripheral liquid flow path portion 14.
According to this, as can be seen from FIG. 20, the vapor flow path is narrowed with respect to the inner liquid flow path portion 15', but the size of the condensed liquid flow path (liquid flow path groove) is arranged in the steam flow path. Can be increased. Therefore, the condensate is more likely to enter the condensate flow path at the site, and the smooth reflux of the working fluid is improved.
Further, since there is no steam flow path communication groove in this portion, the strength of the first sheet 10'can be increased, and the strength of the vapor chamber as a whole can be increased. In particular, the vapor chamber is easily deformed because it is evacuated and joined in the manufacturing process. On the other hand, in the vapor chamber 61, deformation can be suppressed by having a structure like the inner liquid flow path portion 15'.

21 and 22 show diagrams illustrating the vapor chamber 71 according to the fourth embodiment. 21 (a) shows a view of the second sheet 20 ”viewed from the inner surface side, FIG. 21 (b) shows a view of the first sheet 10 seen from the inner surface side, and FIG. 22 shows FIG. 21 (? a), the cut surface of the vapor chamber 71 at the site shown by XXII-XXII in FIG. 21 (b).

In the vapor chamber 71 of this embodiment, the first sheet 10 is the same as the vapor chamber 1.
Further, in the second sheet 20 ", the inner liquid flow path portion 25 of the second sheet 20" is formed longer than the inner liquid flow path portion 15 of the first sheet 10, and the vapor flow path communication groove 27 "is formed in the portion. Is arranged so as to be closer to the outer peripheral liquid flow path portion 24 in a narrower width than the steam flow path communication groove 27 of the second sheet 20.
According to this, as can be seen by comparing FIG. 22 with FIG. 15, in the steam flow path communication groove, the steam flow path becomes narrower at this portion, and the condensed liquid flow of the inner liquid flow path portion 15 at this portion. The path is not placed in the steam flow path. However, the outer peripheral liquid flow path portion 14 can take a form arranged in the steam flow path 4.
According to this, since the steam flow path communication groove is formed narrowly, the strength of the second sheet 20 "can be increased, and the strength of the vapor chamber as a whole can be increased. Especially in the vapor chamber, the manufacturing process thereof. Since it is evacuated or joined, it is easily deformed. On the other hand, the vapor chamber 71 can suppress the deformation.
On the other hand, since the outer peripheral liquid flow path portion 14 can take the form formed in the vapor flow path 4, it is possible to facilitate the reflux of the condensed liquid as described above.

1 Vapor chamber 2 Sealed space 3 Condensate flow path 4 Steam flow path 10 First sheet 10a Inner surface 10b Outer surface 10c Side surface 11 Main body 12 Injection part 13 Outer peripheral joint 14 Outer peripheral liquid flow path 14a Liquid flow path groove 14c Liquid communication opening 15 Inner liquid flow path 15a Liquid flow path groove 15c Liquid communication opening 16 Steam flow path groove 17 Steam flow path communication groove 20 Second sheet 20a Inner surface 20b Outer surface 20c Side surface 21 Main body 22 Injection part 23 Outer peripheral joint part 24 Outer liquid flow path part 25 Inner liquid flow path 26 Steam flow path groove 27 Steam flow path communication groove

Claims (7)

It has a first sheet and a second sheet that is overlapped and joined to the first sheet, and a closed space is formed between the first sheet and the second sheet, and the space operates in the space. A vapor chamber filled with fluid,
In the space, a plurality of condensate flow paths through which the liquid in which the working fluid is condensed flows by superimposing the first sheet and the second sheet, and a steam flow path through which the vapor vaporized by the working fluid flows. , Is formed,
A part of the condensate flow path is formed in the steam flow path, and the condensate flow path is formed.
The first sheet is provided with ridges and dents repeatedly on the side overlapping the second sheet.
The second sheet is provided with ridges and dents repeatedly on the side overlapping the first sheet.
A plurality of grooves are formed in at least one of the ridges of the first sheet and the ridges of the second sheet.
By superimposing the ridges on the first sheet and the ridges on the second sheet, the plurality of grooves are made into the condensed liquid flow path.
One of the ridges of the first sheet and the ridges of the second sheet is formed longer than the other.
Vapor chamber. It has a first sheet and a second sheet that is overlapped and joined to the first sheet, and a closed space is formed between the first sheet and the second sheet, and the space operates in the space. A vapor chamber filled with fluid,
The first sheet is provided with ridges and dents repeatedly on the side overlapping the second sheet.
The second sheet is provided with ridges and dents repeatedly on the side overlapping the first sheet.
A plurality of grooves are formed in at least one of the ridges of the first sheet and the ridges of the second sheet.
By superimposing the ridges on the first sheet and the ridges on the second sheet, the plurality of grooves are made into a plurality of condensate flow paths through which the condensate of the working fluid flows.
By superimposing the recess on the first sheet and the recess on the second sheet, the working fluid is made into a steam flow path through which vaporized vapor flows.
A part of the condensed liquid flow path is formed in the steam flow path.
Vapor chamber. The condensed liquid flow path includes a liquid flow path groove which is a plurality of parallel grooves.
The liquid flow path groove, which is a part of the plurality of liquid flow path grooves, has an opening at a portion opposite to the bottom of the groove, and the opening forms a part of the steam flow path. , The vapor chamber according to claim 1 or 2. The vapor chamber according to claim 3, wherein the liquid flow path grooves other than the partial liquid flow path grooves among the plurality of liquid flow path grooves have the openings closed. The vapor chamber according to claim 3 or 4, wherein the plurality of liquid flow path grooves communicate with the adjacent liquid flow path groove by an opening. The plurality of condensed liquid flow paths include an annular condensed liquid flow path extending along the outer periphery of the space and a condensed liquid flow path arranged inside the ring of the annular condensed liquid flow path. Item 6. The vapor chamber according to any one of Items 1 to 5. When the plurality of grooves are provided in any one of the ridges of the first sheet and the ridges of the second sheet, the ridges provided with the plurality of grooves are formed by the plurality of grooves. The vapor chamber according to claim 1, which is formed longer than a ridge that is not provided .

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