JP7099094B2 - Vapor chamber and electronic equipment - Google Patents

Description

The present invention relates to a vapor chamber in which a working fluid enclosed in a closed space transfers heat while self-excited and vibrating with a phase change.

Electronic components such as CPUs (Central Processing Units) are used in electronic devices represented by personal computers and portable terminals such as mobile phones and tablet terminals. Since the amount of heat generated from such electronic components tends to increase due to the improvement of information processing capability, a technique for cooling the information processing capacity is important.
Heat pipes are well known as a means for cooling. In this method, the working fluid enclosed in the pipe diffuses the heat in the heat source by transporting it to another part by utilizing the phase change, and cools the heat source.

On the other hand, in recent years, the thinning of these electronic devices has been remarkable, and a cooling means thinner than the conventional heat pipe has been required. On the other hand, a vapor chamber has been proposed. The vapor chamber, sometimes called a sheet type heat pipe, is a device that develops the concept of heat transfer by a 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 heat in the heat source is transported and diffused by utilizing the phase change of the working fluid to cool the heat source.

As such a heat pipe or vapor chamber, depending on the driving force of movement of the working fluid, a capillary force type as in Patent Document 1, a self-excited vibration type as in Patent Document 2, and a composite type of both as in Patent Document 3 are available. Proposed.

Japanese Unexamined Patent Publication No. 2009-07650 International Publication No. WO2016 / 035436 Japanese Patent Application Laid-Open No. 2003-302180

In the heat pipe and vapor chamber, one of the problems that the heat transport ability cannot be exhibited is the dry out in the evaporation part. This is because the working fluid undergoes a phase change from liquid to steam due to heat, and the liquid is not properly supplied to the part where the heat source should be cooled, so phase change cannot occur and the heat source cannot be cooled. It is to be in a state.
As described above, the thinning of electronic devices has been remarkable in recent years, and the heat pipes and vapor chambers are also required to be thinned and downsized, so that dryout is likely to occur. And even with the above-mentioned conventional heat pipes and vapor chambers, this dryout could not be sufficiently avoided.

In addition, electronic devices equipped with heat pipes and vapor chambers are expected to be used in various environments, including sub-zero environments. And in a vapor chamber that uses a working fluid, the working fluid may freeze in a sub-zero environment. When the working fluid freezes, the volume increases, and as a result, the frozen working fluid pushes the two flat plates that make up the vapor chamber in the direction to separate them and applies force, which causes the problem of breaking the wall connecting the two flat plates. be. Such fracture is rarely caused by one freezing of the working fluid, but repeated freezing and melting of the working fluid causes accumulation of plastic deformation, which eventually results in fracture due to wall fracture. The breakage causes leakage of the working fluid, which may cause a short circuit in the surrounding electronic components and damage the electronic device. In order to prevent such destruction, for example, a space serving as a buffer for volume expansion may be provided in the space in which the working fluid is enclosed. However, such a space is not preferable from the viewpoint of thinning and high performance (improvement of heat transport capacity) of the vapor chamber, but rather may hinder the high performance.

Therefore, in view of the above problems, it is an object of the present invention to provide a vapor chamber capable of obtaining a high heat transport capacity even if the thickness is reduced and suppressing fracture. Also provided is an electronic device equipped with this vapor chamber.

One aspect of the present invention is a vapor chamber in which a closed space is formed between a plurality of sheets and a working fluid is sealed in the closed space, and the working fluid is in a state of a condensate in the closed space. It is equipped with a condensate flow path, which is a flow path that moves in, and a steam flow path, which has a larger flow path cross-sectional area than the condensate flow path and in which the working fluid self-excited and vibrates in the state of steam and condensate. The condensate flow path is formed by arranging a plurality of linear condensate flow paths between the two vapor flow paths, and the plurality of vapor flow paths are in communication with each other, and the vapor flow path and the condensate flow path are arranged. It is a vapor chamber in which the structure in the region is configured to be symmetrical with a line parallel to the condensate flow path arranged in a straight line as an axis.

A plurality of steam channels may be formed so as to communicate with each other.

The structure in the region where the vapor flow path and the condensate flow path are arranged may be further configured to be symmetrical with respect to the line orthogonal to the condensate flow path arranged in a straight line.

Further, an annular condensate flow path may be provided along the edge of the enclosed space.

The thickness of the vapor chamber can be 0.4 mm or less.

Another aspect of the present invention comprises a housing, an electronic component disposed inside the housing, and the vapor chamber arranged in direct contact with the electronic component or in contact with the electronic component via another member. , An electronic device. In that case, the electronic component may be arranged at a position overlapping the axis by a line parallel to the condensate flow path arranged in a straight line of the vapor chamber when the vapor chamber is viewed in a plan view.

According to the present invention, in the steam flow path, the working fluid moves by self-excited vibration to efficiently transfer and diffuse heat, and the condensed liquid flow path provided separately from the steam flow path allows the working fluid to move and diffuse. Since the condensate can be efficiently moved and refluxed by the capillary force, it is possible to suppress the occurrence of dryout.
In addition, since the vapor flow path and the condensate flow path are arranged symmetrically, the balance of self-excited vibration is maintained and the vibration is stable when the vapor chamber is operated, so that high heat transport capacity can be stably exhibited. .. On the other hand, when the vapor chamber is not activated, the condensed liquid is dispersed over the entire vapor chamber and prevented from concentrating in one place, so that the vapor chamber is destroyed even if the working fluid freezes and expands. Can be prevented.
Therefore, even if the working fluid is used in an environment where the working fluid freezes, all of the thinning, heat transport capacity, and durability are satisfied.

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. 6 (a) to 6 (c) are views showing walls and liquid communication openings of other forms. FIG. 7 is an enlarged view of a part of the outer peripheral liquid flow path portion 14 of another example in a plan view. 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. 9 (a) is a perspective view of the second sheet 20, and FIG. 9 (b) is a plan view of the second sheet 20. FIG. 10 is a cut surface of the second sheet 20. FIG. 11 is another cut surface 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. FIG. 14 is a cross-sectional view taken along the line XIV-XIV of FIG. 1 (a). FIG. 15 is a diagram illustrating the structure of the closed space 2 of the vapor chamber 1 and showing symmetry. FIG. 16 is a perspective view illustrating the electronic device 40. FIG. 17 is a diagram illustrating the operation of the vapor chamber 1. FIG. 18A is a perspective view of the second sheet 120, and FIG. 18B is a diagram illustrating the structure of the enclosed space of the vapor chamber 101. 19 (a) is a perspective view of the second sheet 120', and FIG. 19 (b) is a diagram illustrating the structure of the enclosed space of the vapor chamber 101'. FIG. 20 (a) is a diagram illustrating the structure of the enclosed space of the vapor chamber 201, and FIG. 20 (b) is a part of the cut surface of the vapor chamber 201. FIG. 21 is a diagram for explaining the structure of the closed space 302 of the vapor chamber 301, and is a diagram showing that the steam flow path communicates with another steam flow path at both ends. FIG. 22 is an external perspective view of the vapor chamber 401. FIG. 23 is an exploded perspective view of the vapor chamber 401. FIG. 24A is a view of the third sheet 430 viewed from one side, and FIG. 24B is a view of the third sheet 430 viewed from the other side. FIG. 25 is a cut surface of the third sheet 430. FIG. 26 is another cut surface of the third sheet 430. FIG. 27 is a cut surface of the vapor chamber 401. FIG. 28 is an enlarged view of a part of FIG. 27. FIG. 29 is another cut surface of the vapor chamber 401.

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. For convenience, arrows (x, y, z) indicating directions orthogonal to each other are also shown in these figures and each of the figures shown below. Here, the in-plane direction of the xy is the direction along the plate surface of the vapor chamber 1 which is a flat plate, 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 the cut surface of the first sheet 10 when cut in III-III of 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 forming a thickness across the inner surface 10a and the outer surface 10b, and a flow in which the working fluid moves toward the inner surface 10a. A pattern for the road is formed. 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 moves, and in this embodiment, it is a rectangle having an arc (so-called R) at an angle 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. In particular, by using copper and a copper alloy, it becomes easy to manufacture a vapor chamber by etching and diffusion bonding as described later while improving the heat transport capacity.

A structure for moving 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 joining 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 surface formed on the inner surface 10a side of the main body 11 along the outer circumference of the main body 11. By overlapping the outer peripheral joint portion 13 with the outer peripheral joint portion 23 of the second sheet 20 and joining (diffusion joining, brazing, etc.), a closed space 2 is formed 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 A10 in FIGS. 2 (b) and 3 can be appropriately set as needed, but is preferably 0.8 mm or more and 3.0 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 3.0 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 (see, for example, FIG. 13), which is a flow path through which the working fluid is condensed and liquefied. be. FIG. 4 (a) shows the portion of FIG. 3 indicated by the arrow IVa, and FIG. 4 (b) shows the cut surface 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, liquid flow path grooves 14a, which are a plurality of grooves extending in parallel to the outer peripheral direction of the main body 11, are formed, and the plurality of liquid flow path grooves 14a are formed by the liquid flow path grooves 14a. They are arranged at intervals in a direction different from the extending direction. Therefore, as can be seen from FIGS. 4 (a) and 4 (b), in the outer peripheral liquid flow path portion 14, the wall which is a convex portion between the liquid flow path groove 14a which is a concave portion and the liquid flow path groove 14a in the cross section thereof. 14b and 14b are formed by repeating unevenness.
Here, since the liquid flow path groove 14a is a groove, it has a bottom portion and an opening formed on the opposite side facing the bottom portion in its cross-sectional shape.

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 of the condensed liquid flow path 3 (see, for example, FIG. 13) is interrupted. A large capillary force can be utilized by reducing the area. On the other hand, by having a plurality of liquid flow path grooves 14a, the total internal volume of the condensed liquid flow path 3 is secured to 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, the adjacent liquid flow path grooves 14a communicate with each other by the liquid communication openings 14c provided at intervals in the wall 14b. As a result, equalization of the amount of condensed liquid is promoted among the plurality of liquid flow path grooves 14a, and the condensed liquid can be efficiently flowed. Further, the liquid communication opening 14c provided in the wall 14b adjacent to the vapor flow path groove 16 forming the vapor flow path 4 communicates the vapor flow path 4 and the condensed liquid flow path 3. Therefore, by configuring the liquid communication opening 14c, the condensate generated in the steam flow path 4 can be smoothly moved to the condensate flow path 3, and the steam generated in the condensate flow path 3 can be smoothly vaporized. It can also be moved to the flow path 4, which also makes it possible to promote a smooth flow of the working fluid without interfering with the self-excited vibration of the working fluid.

6 (a) to 6 (c) show one condensate flow path 14a, two walls 14b sandwiching the condensate flow path 14a, and one liquid communication opening provided in each wall 14b from the same viewpoint as in FIG. The figure which showed the part 14c is shown. In each of these, the shape of the wall 14b is different from the example of FIG. 5 from the viewpoint (plan view).
That is, in the wall 14b shown in FIG. 5, the width (C ₂ ) is the same as that of other parts and is constant even at the end portion where the liquid communication opening 14c is formed. On the other hand, in the wall 14b having the shapes shown in FIGS. 6A to 6C, the width thereof is larger than the maximum width ( _C2 ) of the wall 14b at the end where the liquid communication opening 14c is formed. Is also formed to be small. More specifically, in the example of FIG. 6 (a), the corners are arcuate at the end and the width of the end is reduced due to the formation of R at the corner, and in FIG. 6 (b), the end is An example in which the width of the end portion is reduced due to the semicircular shape, and FIG. 6 (c) is an example in which the end portion is tapered so as to be sharpened.

As shown in FIGS. 6A to 6C, the width of the wall 14b at the end where the liquid communication opening 14c is formed is smaller than the maximum width ( _C2 ) of the wall 14b. By being formed in, the working fluid can easily move through the liquid communication opening 14c, and the working fluid can easily move to the adjacent condensate flow path 3.

In this embodiment, as shown in FIG. 5, the liquid communication opening 14c is arranged so as to face the same position in the direction in which the liquid flow path groove 14a extends across the groove of one liquid flow path groove 14a. However, the present invention is not limited to this, and for example, as shown in FIG. 7, the liquid communication openings 14c are located at different positions in the direction in which the liquid flow path groove 14a extends across the groove of one liquid flow path groove 14a. It may be arranged. That is, in this case, the liquid communication opening 14c is arranged at an offset.
By providing the liquid communication opening 14c at such an offset, the liquid communication opening 14c does not appear on both sides at the same time when viewed from the working fluid traveling in the condensed liquid flow path 3, and the liquid communication opening 14c does not appear at the same time. There is always a wall 14b on at least one side of the wall even if it appears. Therefore, the capillary force can be continuously obtained. From this point of view, by forming the liquid communication opening 14c at an offset, the capillary force acting on the working fluid can be maintained high, so that smoother reflux is possible.
Further, even when the liquid communication openings 14c are offset and arranged in this way, the end shape of the wall 14b can be configured according to the examples of FIGS. 6 (a) to 6 (c).

It is preferable that the outer peripheral liquid flow path portion 14 having the above configuration further has the following configuration.
The width of the outer peripheral liquid flow path portion 14 shown by B ₁₀ 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. However, it is preferably 0.3 mm or more and 2 mm or less. If this width is smaller than 0.3 mm, the amount of liquid flowing outside may not be sufficient. Further, if this width exceeds 2 mm, there is a possibility that sufficient space for the inner condensate flow path and steam flow path cannot be obtained.

Regarding the liquid flow path groove 14a, the groove width shown by C1 in FIGS. 4 (a), 5 and 6 (a) to 6 (c) is preferably ₁₀ μm or more and 300 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 condensate flow path required for the liquid to flow can be sufficiently exerted. Here, the groove depth D is preferably smaller than the remaining sheet thickness obtained by subtracting the groove depth D from the thickness of the first sheet 10. This makes it possible to more reliably prevent the sheet from being torn when the working fluid is frozen.
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 ₁ / D is preferably larger than 1.0 or smaller than 1.0. .. Among them, from the viewpoint of production, C ₁ > D is preferable, and the aspect ratio is preferably larger than 1.3.

Further, with respect to the wall 14b, the width shown by _C2 in FIGS. 4 (a), 5 and 6 (a) to 6 (c) is preferably 20 μm or more and 300 μm or less. If this width is smaller than 20 μm, it is likely to break due to repeated freezing and melting of the working fluid, and if this width is larger than 300 μm, the width of the liquid communication opening 14c becomes too large, and the width of the liquid communication opening 14c becomes too large. Smooth communication of the working fluid may be hindered.

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 is extended 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 _C4 in FIG. 5 extends is 300 μm or more and 2700 μm or less.

In this embodiment, the cross-sectional shape of the liquid flow path groove 14a is a semi-elliptical shape, but the cross-sectional shape is not limited to this, and is not limited to this. And so on.

Further, it is preferable that the liquid flow path groove 14a is continuously formed along the edge in the closed space. That is, it is preferable that the liquid flow path groove 14a extends in an annular shape over one circumference without being cut off by other components. As a result, the factors that hinder the movement of the condensed liquid are reduced, so that the condensed liquid can be moved smoothly.

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 and extends in a direction parallel to the long side (x direction). The plurality of (three in this embodiment) inner liquid flow path portions 15 are arranged at intervals in the direction parallel to the short side (y direction), and are arranged between the steam flow path grooves 16. There is.
In each inner liquid flow path portion 15, a liquid flow path groove 15a which is a linear 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 form the liquid flow path. The grooves 15a 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 wall 15b which is a convex portion between the liquid flow path groove 15a which is a concave portion and the liquid flow path groove 15a in the cross section is uneven. Is formed repeatedly.
Here, since the liquid flow path groove 15a is a groove, it has a bottom portion and an opening formed on the opposite side facing the bottom portion in its cross-sectional shape.

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. 13) 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 internal volume of the condensed liquid flow path 3 is secured to an appropriate size, and the condensed liquid having a required flow rate can flow.

Further, also in the inner liquid flow path portion 15, as can be seen from FIG. 8B, the adjacent liquid flow path grooves 15a are formed on the wall 15b in the same manner as in FIG. 5, following the example of the outer peripheral liquid flow path portion 14. The liquid communication openings 15c are provided at intervals to communicate with each other. As a result, equalization of the amount of condensed liquid is promoted among the plurality of liquid flow path grooves 15a, and the condensed liquid can be efficiently flowed. Further, the liquid communication opening 15c provided in the wall 15b adjacent to the vapor flow path groove 16 forming the vapor flow path 4 communicates the vapor flow path 4 and the condensed liquid flow path 3. Therefore, as will be described later, by configuring the liquid communication opening 15c, the condensate generated in the vapor flow path 4 can be smoothly moved to the condensate flow path 3, and the condensate is generated in the condensate flow path 3. The steam can be smoothly moved to the steam flow path 4, which also makes it possible to promote the smooth flow of the working fluid without hindering the self-excited vibration of the working fluid.

The width of the inner liquid flow path portion 15 is the largest of the wall 15b at the end where the liquid communication opening 15c is formed with respect to the wall 15b according to the example of FIGS. 6 (a) to 6 (c). It may be formed so as to be smaller than significantly.
This facilitates the movement of the working fluid through the liquid communication opening 15c.

Further, with respect to the inner liquid flow path portion 15, the liquid communication opening 15c is provided at different positions in the direction in which the liquid flow path groove 15a extends across the groove of one liquid flow path groove 15a, following the example of FIG. It may be arranged.
By providing the liquid communication opening 15c at such an offset, the liquid communication opening 15c does not appear on both sides at the same time when viewed from the working fluid traveling in the condensed liquid flow path 3, and the liquid communication opening 15c does not appear at the same time. However, there is always a wall 15b on at least one side surface. Therefore, the capillary force can be continuously obtained. From this point of view, by forming the liquid communication opening 15c at an offset, the capillary force acting on the working fluid can be maintained high, so that the working fluid can move more smoothly.
Further, even when the liquid communication openings 15c are offset and arranged in this way, the end shape of the wall 15b can be configured according to the examples of FIGS. 6A to 6C.

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 E10 in FIGS. 2B, 3 and 8 is preferably 100 μm or more and 2000 μm or less. 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 reduced, and the self-excited vibration 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.

Regarding the liquid flow path groove 15a, the groove width shown by F1 in FIGS. 8 ( _a ) and 8 (b) is preferably 10 μm or more and 300 μm or less.
Further, the depth of the groove shown by G 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 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 torn when the working fluid is frozen.
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 F ₁ / G is preferably larger than 1.0 or smaller than 1.0. .. Among them, from the viewpoint of production, F ₁ > G is preferable, and the aspect ratio is preferably larger than 1.3.

Further, with respect to the wall 15b, the width shown by F2 in FIGS. ₈ (a) and 8 (b) is preferably 20 μm or more and 300 μm or less. If this width is smaller than 20 μm, it is likely to break due to repeated freezing and melting of the working fluid, and if this width is larger than 300 μm, the width of the liquid communication opening 14c becomes too large, and smooth communication between the condensed liquid flow paths 3 is performed. May be hindered.

With respect to the liquid communication opening 15c, the size of the opening along the direction in which the liquid flow path groove 15a shown in FIG. 8B ₃ 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 shown in FIG. 8B is extended is 300 μm or more and 2700 μm or less.

Further, in the present embodiment, the cross-sectional shape of the liquid flow path groove 15a is a semi-elliptical shape, but the cross-sectional shape is not limited to this, but is limited to a quadrangle 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.

Next, the steam flow path groove 16 will be described. The vapor flow path groove 16 is a portion where the vapor-like and condensed liquid working fluids self-excited and vibrate, and constitutes a part of the vapor 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 linear groove 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. 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, it has a bottom portion and an opening formed on the opposite side facing the bottom portion in its cross-sectional shape.

The steam flow path groove 16 is configured so that when the steam flow path 4 is formed in combination with the steam flow path groove 26 of the second sheet 20, self-excited vibration of the working fluid occurs in the steam flow path 4. Just do it. Therefore, it is preferable that the steam flow path groove 16 further has the following configuration.
The width of the vapor flow path groove 16 shown by _H10 in FIGS. 2 (b) and 3 is formed to be at least larger than the width C ₁ of the liquid flow path groove 14a and the width F ₁ of the liquid flow path groove 15a described above. It is preferably 100 μm or more and 2000 μm or less.
On the other hand, the depth of the vapor flow path groove 16 shown by I ₁₀ in FIG. 3 is formed to be at least larger than the depth D of the liquid flow path groove 14a and the depth G of the liquid flow path groove 15a described above, and is 10 μm or more and 300 μm. The following is preferable.
As a result, stable self-excited vibration of the working fluid is obtained when the vapor flow path is formed, and the flow path cross-sectional area of the vapor flow path groove is made larger than that of the liquid flow path groove, whereby the properties of the working fluid are obtained. In addition, steam, which has a larger volume than the condensate, can be smoothly moved.

Here, when the steam flow path 4 is formed by combining the steam flow path groove 16 with the second sheet 20 as described later, the width of the steam flow path 4 is high (the size in the thickness direction). It is preferable that the shape is larger than that of the flat shape. Therefore, the aspect ratio indicated by H ₁₀ / I ₁₀ is preferably 4.0 or more, more preferably 8.0 or more.

In this embodiment, the cross-sectional shape of the steam flow path groove 16 is a semi-elliptical shape, but the cross-sectional shape is not limited to this, but is limited to a quadrangle such as a square, a rectangle, a trapezoid, a triangle, a semi-circle, a semi-circular bottom, and a semi-elliptical bottom. You may.

The steam flow path communication groove 17 communicates a plurality of steam flow path grooves 16 and is combined with the steam flow path communication groove 27 of the second sheet 20 to form a plurality of steam flow paths 4 by the steam flow path groove 16 at the end thereof. It is a groove that forms a flow path that communicates with. This makes it possible to balance the self-excited vibration of the working fluid generated in the steam flow path 4 in the direction in which the inner liquid flow path portion 15 extends.
Further, as a result, the working fluid in the steam flow path 4 can be equalized, or steam can be carried in a wider range, and the efficiency of the condensed liquid flow path 3 by many liquid flow path grooves 14a and the liquid flow path groove 15a can be achieved. It will also be available well.

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 able to communicate with the adjacent steam flow path grooves 16, and its shape is not particularly limited, but may include, for example, the following configuration.
The width of the steam flow path communication groove ₁₇ shown by J10 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 K ₁₀ in FIG. 4 (b) is preferably 10 μm or more and 300 μm or less, and is the same as the depth I ₁₀ of the steam flow path groove 16. Is preferable. This facilitates manufacturing.

In this embodiment, the cross-sectional shape of the steam flow path communication groove 17 is semi-elliptical, but the cross-sectional shape is not limited to this, but is limited to squares, rectangles, trapezoids and other quadrangles, triangles, semi-circles, bottoms are semi-circular, bottoms are semi-elliptical, etc. It may be.

Further, as will be described later, when the vapor chamber 1 is considered in the closed space 2 surrounded by the joined portions, that is, the region provided with the condensate flow path 3 and the vapor flow path 4 is considered. The provided shape is a symmetric shape with an axis parallel to the direction in which the condensate flow path 3 formed by the inner liquid flow path portion 15 and the inner liquid flow path portion 25 extends as an axis of symmetry.
Therefore, for this purpose, also for the first sheet 10, the outer peripheral liquid flow path portion 14 and the shape provided inside the outer peripheral liquid flow path portion 14 have an axis symmetrical to the axis parallel to the direction in which the liquid flow path groove 15a extends (IIb in FIG. 2B). -IIb) is considered to be symmetric.

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. 9A shows a perspective view of the second sheet 20 as seen from the inner surface 20a side, and FIG. 9B shows a plan view of the second sheet 20 as seen from the inner surface 20a side. Further, FIG. 10 shows a cut surface of the second sheet 20 when cut by XX in FIG. 9 (b). Further, FIG. 11 shows a cut surface of the second sheet 20 when cut by XI-XI in FIG. 9 (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 that passes between the inner surface 20a and the outer surface 20b to form a thickness, and a pattern in which the working fluid moves toward the inner surface 20a. Is formed. As will be described later, the closed space 2 is formed by overlapping and joining 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 moves, and in this embodiment, it is a rectangle having an arc (so-called R) at an angle 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 moving the working fluid is formed on the inner surface 20a side of the main body 21. Specifically, the inner surface 20a side of the main body 21 is provided with an outer peripheral joining 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 surface formed on the inner surface 20a side of the main body 21 along the outer periphery 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 by A ₂₀ in FIGS. 9 (b), 10 and 11 is the same as the width A ₁₀ of the outer peripheral joint portion 13 of the main body 11.

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 functions as a liquid flow path portion, and is a portion constituting a part of the condensed liquid flow path 3 (see, for example, FIG. 13), which is a flow path through which the working fluid is condensed and liquefied. be.

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 circumference of the closed space 2. In the present embodiment, as can be seen from FIGS. 10 and 11, the outer peripheral liquid flow path portion 24 of the second sheet 20 is a flat surface and flush with the outer peripheral joint portion 23 before being joined to the first sheet 10. 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 with each other, there is no structural boundary line for distinguishing between the two. However, for the sake of clarity, the boundary between the two is represented by a dotted line in FIGS. 9 (a) and 9 (b).

The outer peripheral liquid flow path portion 24 preferably has the following configuration.
The width B ₂₀ of the outer peripheral liquid flow path portion 24 shown in FIGS. 9 (b), 10 and 11 is not particularly limited and is the same as the width B ₁₀ of the outer peripheral liquid flow path portion 14 of the first sheet 10. It may or may not be different. In this embodiment, the width B ₁₀ and the width B ₂₀ are the same.
When the width B ₂₀ is made smaller than the width B ₁₀ , the opening of the liquid flow path groove 14a is opened without being closed by the outer peripheral liquid flow path portion 24 in at least a part of the outer peripheral liquid flow path portion 14, and is condensed from here. Since the liquid easily enters and the steam easily exits, the working fluid can move more smoothly.

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. 9 (a), 9 (b), 10 and 11, the inner liquid flow path portion 25 is an annular ring of the outer liquid flow path portion 24 of the inner surface 20a of the main body 21. It is formed inside. 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 linear ridge extending in a direction parallel to the long side (x direction), and a plurality of (three in this embodiment) inner liquid flow flows. The road portions 25 are arranged between the steam flow path grooves 26 at predetermined intervals in a direction parallel to the short side (y direction).
In the present embodiment, each inner liquid flow path portion 25 is formed so that the surface on the inner surface 20a side thereof becomes a flat surface before joining with the first sheet 10. 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.
When the groove for forming the condensate flow path 3 is not formed in the inner liquid flow path portion 25 as in the present embodiment, the thickness of the second sheet 20 is the liquid flow path groove of the first sheet 10. It is preferably at least a depth G of 15a (see FIG. 8A). This makes it possible to prevent breakage (tear) on the second sheet side in the vapor chamber.

The width E ₂₀ of the inner liquid flow path portion 25 shown in FIGS. 9 (b) and 10 is not particularly limited, and may be the same as the width E ₁₀ of the inner liquid flow path portion 15 of the first sheet 10. , May be different. In this embodiment, the width E ₁₀ and the width E ₂₀ are the same.
If the width E ₂₀ and the width E ₁₀ are different, the influence of the positional deviation at the time of joining can be reduced. When the width E ₂₀ is made smaller than the width E ₁₀ , the opening of the liquid flow path groove 15a is opened without being closed by the inner liquid flow path portion 25 in at least a part of the inner liquid flow path portion 15. Since the condensed liquid easily enters from here and the generated vapor easily exits, the working fluid can be moved more smoothly.

Next, the steam flow path groove 26 will be described. The vapor flow path groove 26 is a portion where the vapor-like and condensed liquid working fluids self-excited and vibrate, and constitutes a part of the vapor flow path 4. FIG. 9B shows the shape of the steam flow path groove 26 in a plan view, and FIG. 10 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 linear 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. 10, in the second sheet 20, in the y direction, ridges are formed in which the outer peripheral liquid flow path portion 24 and the inner liquid flow path portion 25 are convex, and the vapor flow path groove 26 is concave. A dent is formed and has a shape in which these irregularities are repeated.
Here, since the steam flow path groove 26 is a groove, it has a bottom portion and an opening formed on the opposite side facing the bottom portion in its cross-sectional shape.

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.
The width of the steam flow path groove 26 shown by H ₂₀ in FIGS. 9 (b) and 10 is not particularly limited, and may be the same as the width H ₁₀ of the steam flow path groove 16 of the first sheet 10. It may be different. In this embodiment, the width H ₁₀ and the width H ₂₀ are the same.
When the width H ₂₀ and the width H ₁₀ are different, the influence of the positional deviation at the time of joining can be reduced. When the width H ₂₀ is made larger than the width H ₁₀ , the opening of the liquid flow path groove 15a is opened without being closed by the inner liquid flow path portion 25 in at least a part of the inner liquid flow path portion 15. Since the condensate easily enters from here and steam easily exits, the working fluid can move more smoothly.
On the other hand, the depth of the steam flow path groove 26 shown by I ₂₀ in FIG. 10 is preferably 10 μm or more and 300 μm or less.

Here, when the steam flow path 4 is formed by combining the steam flow path groove 26 with the first sheet 10 as described later, the width of the steam flow path 4 is high (the size in the thickness direction). It is preferable that the shape is larger than that of the flat shape. Therefore, the aspect ratio indicated by H ₂₀ / I ₂₀ is preferably 4.0 or more, more preferably 8.0 or more.

In the present embodiment, the cross-sectional shape of the steam flow path groove 26 is a semi-elliptical shape, but it may be a quadrangle such as a square, a rectangle, or a trapezoid, a triangle, a semi-circular shape, a semi-circular bottom, and a semi-elliptical bottom.

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 with the ends of a plurality of steam flow paths 4 by the steam flow path groove 26. .. This makes it possible to balance the self-excited vibration of the working fluid generated in the steam flow path 4 in the direction in which the inner liquid flow path portion 25 extends. In addition, the working fluid of the steam flow path 4 can be equalized, the steam can be carried over a wider range, and many condensate flow paths 3 can be efficiently used, so that the working fluid can be moved. It becomes possible to make it smoother.

As can be seen from FIGS. 9 (b) and 11 in the steam flow path communication groove 27 of the present embodiment, both ends in the direction in which the inner liquid flow path portion 25 extends, both ends in the direction in which the steam flow path groove 26 extends, and both ends in the direction in which the steam flow path groove 26 extends. It is formed between the outer peripheral liquid flow path portion 24 and the outer peripheral liquid flow path portion 24. Further, FIG. 11 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 J ₂₀ in FIGS. 9 (b) and 11 is not particularly limited, and is the same as the width J ₁₀ of the steam flow path communication groove 17 of the first sheet 10. It may be different from the width _J10 . When the width J ₂₀ is made larger than the width J ₁₀ , the opening of the liquid flow path groove 14a forms a part of the steam flow path 4 in at least a part of the outer peripheral liquid flow path portion 14 of the first sheet 10. Since the condensate is arranged in such a manner, the condensed liquid can easily enter and the generated vapor can be easily discharged, so that the working fluid can be moved more smoothly.

The size of the width J ₂₀ is preferably in the range of 100 μm or more and 1000 μm or less, and the depth of the steam flow path communication groove 27 shown by K ₂₀ in FIG. 11 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 semi-elliptical, but the cross-sectional shape is not limited to this, but is limited to squares, rectangles, trapezoids and other quadrangles, triangles, semi-circles, bottoms are semi-circular, and bottoms are semi-elliptical. There may be.

Further, as will be described later, when the vapor chamber 1 is considered in the closed space 2 surrounded by the joined portions, that is, the region provided with the condensate flow path 3 and the vapor flow path 4 is considered. The provided shape is a symmetric shape with an axis parallel to the direction in which the condensate flow path 3 formed by the inner liquid flow path portion 15 and the inner liquid flow path portion 25 extends as an axis of symmetry.
Therefore, for this purpose, the second sheet 20 also has an axis of symmetry about the outer peripheral liquid flow path portion 24 and the inside thereof so that the shape provided is parallel to the direction in which the inner liquid flow path portion 25 extends (FIG. 9 (b)). IXb-IXb) is symmetric.

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. 10 on the second sheet 20 to show the cut surface of the vapor chamber 1 at this site.
FIG. 13 shows an enlarged view of the portion shown by XIII in FIG.
FIG. 14 shows a cut surface cut in the thickness direction of the vapor chamber 1 along the x direction shown by XIV-XIV in FIG. 1 (a). This figure is a combination of the figure shown in FIG. 4 (b) of the first sheet 10 and the figure shown in FIG. 11 of the second sheet 20 to show the cut surface of the vapor chamber 1 at this site. Is.

As can be seen from FIGS. 1 (a), 1 (b), and FIGS. 12 to 14, 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 22 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 14. 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 vapor chamber 1 of the present embodiment is particularly effective when it is thin. From this point of view, the thickness of the vapor chamber 1 shown by _L0 in FIGS. 1 and 12 is 1 mm or less, more preferably 0.4 mm or less, still more preferably 0.2 mm or less. By setting the diameter 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, groove formation) for forming a space for arranging the vapor chamber. Will increase. According to this embodiment, the working fluid can be smoothly moved even in such a thin vapor chamber.

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 groove 14a of the outer peripheral liquid flow path portion 14 and the outer peripheral liquid flow path portion 24 form a condensed liquid flow path 3 through which the condensed liquid in a state in which the working fluid is condensed and liquefied flows.
Similarly, 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, it is preferable that the cross-sectional shape of the condensate flow path 3 becomes flat as the vapor chamber 1 becomes thinner. As a result, the capillary force can be increased, and the condensate can be moved more smoothly, so that the heat transport capacity can be maintained at a high level. More specifically, it is preferable that the ratio represented by the width / height of the condensed liquid flow path 3 is larger than 1.0 and 4.0 or less.
At this time, the width of the condensed liquid flow path 3 conforms to the width F ₁ of the liquid flow path groove 15a in this embodiment, but is preferably 10 μm or more and 300 μm or less. If the width is smaller than 10 μm, the flow path resistance may increase and the transport capacity may decrease. On the other hand, if the width is larger than 300 μm, the capillary force becomes small and the transport capacity may decrease.
Further, the height of the condensed liquid flow path 3 conforms to the depth G of the liquid flow path groove 15a in this embodiment, but is preferably 5 μm or more and 200 μm or less. As a result, the capillary force of the condensate flow path required for movement can be sufficiently exerted. It is preferable that this height is 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. .. This makes it possible to further prevent breakage (breakage) of the vapor chamber due to the condensate flow path 3.

In this embodiment, since the liquid flow path groove 14a and the liquid flow path groove 15a are provided only on the first sheet 10, the height of the condensed liquid flow path is the depth of the liquid flow path groove 14a and the liquid flow path groove 15a. However, the present invention is not limited to this, and the second sheet 20 may also be provided with a liquid flow path groove. In this case, the liquid flow path groove of the first sheet and the liquid flow path groove of the second sheet overlap to form a condensed liquid flow path, and the condensed liquid conforms to the total depth of both liquid flow path grooves. It is the height of the flow path.

Further, as described above, the liquid communication opening 14c and the liquid communication opening 15c are formed with respect to the condensed liquid flow path 3. As a result, the plurality of condensed liquid flow paths 3 communicate with each other, the condensed liquid is equalized, and the condensed liquid is efficiently moved. Further, with respect to the liquid communication opening 14c and the liquid communication opening 15c adjacent to the steam flow path 4 and communicating the steam flow path 4 and the condensate flow path 3, the condensate generated in the steam flow path 4 is smoothly condensed. It can be moved to the liquid flow path 3 and the vapor generated in the condensate flow path 3 can be smoothly moved to the steam flow path 4, so that the working fluid can be moved quickly.

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

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 overlap each other to form a flow path, which causes the working fluid to self-excited and vibrate. Will be.
Here, it is preferable that the steam flow path 4 has a flat cross-sectional shape as the vapor chamber 1 becomes thinner. As a result, it is possible to secure the surface area in the flow path even if the thickness is reduced, and it is possible to maintain the heat transport capacity at a high level. More specifically, in the width WB and height H _B of the steam flow path 4 shown in FIG. 13, the ratio represented by _WB / _{H B is} preferably 2.0 or more. From the viewpoint of ensuring a higher heat transport capacity, the ratio is more preferably 4.0 or more.

As can be seen from FIG. 14, the steam flow path is formed by overlapping 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 so as to face each other. A plurality of steam flow paths 4 formed by the groove 16 and the steam flow path groove 26 communicate with each other at their ends to provide a flow path for balancing the self-excited vibration of the working fluid.

With the condensate flow path 3 and the steam flow path 4 as described above, the vapor chamber 1 has a shape in which a plurality of linear condensate flow paths 3 are arranged between the two steam flow paths 4. .. As a result, the condensed liquid flow path 3 in which the condensed liquid should mainly flow and the steam flow path 4 in which the steam mainly self-oscillates are separated and arranged alternately, and the smooth movement of the working fluid is assisted. ..

Due to the steam flow path 4 and the condensate flow path 3 in the closed space 2, the working fluid vibrates due to self-excited vibration in the steam flow path 4, and heat is efficiently transferred and diffused in the steam flow path 4. On the other hand, since the condensed liquid moves efficiently by the capillary force due to the condensed liquid flow path 3 provided separately from the steam flow path 4, it is possible to suppress the occurrence of dryout.

As shown in FIG. 1, the injection portion 12 and the injection portion 22 are overlapped so that the inner surfaces 10a and the inner surfaces 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. An injection flow path 5 is formed which is closed from the inner surface 10a of the injection portion 12 of the sheet 10 and communicates with the outside and the closed space 2 (condensate flow path 3 and steam flow path 4) between the main body 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. do not have.

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.

It is preferable that the vapor chamber 1 as described above further has the following configuration. FIG. 15 shows a diagram for explanation. FIG. 15 is a diagram showing the inside of the vapor chamber 1 as a perspective view, and the enclosed space 2 (that is, in the region where the vapor flow path and the condensate flow path are formed) is shown by a solid line.
The shape of the vapor chamber 1 is the inner liquid when considering the inside of the closed space 2 surrounded by the joined portions, that is, the inside of the region surrounded by the condensate flow path 3 and the vapor flow path 4. The axis parallel to the extending direction of the condensed liquid flow path 3 formed by the flow path portion 15 and the inner liquid flow path portion 25 is a symmetrical axis (XV-XV in FIG. 15).

As a result, the balance of self-excited vibration is maintained when the vapor chamber is operated, and vibration is stably generated, so that high heat transfer capacity can be exhibited with high reliability. On the other hand, when the vapor chamber is not activated, the condensed liquid is dispersed throughout the vapor chamber and prevented from concentrating in one place, so that the vapor chamber is destroyed even if the working fluid freezes and expands. Can be prevented.
Therefore, even if the working fluid is used in an environment where the working fluid freezes, all of the thinning, heat transport capacity, and durability are satisfied.

The vapor chamber as described above can be manufactured, for example, as follows.
The liquid flow path groove 14a, the liquid flow path groove 15a, the steam flow path groove 16, the steam flow path groove 26, and the steam flow path communication groove 17 with respect to the metal sheets having the outer peripheral shapes of the first sheet 10 and the second sheet 20. , The steam flow path communication groove 27 is formed by half etching. Here, half-etching is to remove the material by etching halfway in the thickness direction without penetrating through the thickness direction by etching to form grooves and dents.

Next, the inner surfaces 10a and the inner surfaces 20a of the first sheet 10 and the second sheet 20 are overlapped so as to face each other, and positioning is performed using the holes 13a and 23a as the positioning means, and temporary fixing is performed. 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, a vacuum is drawn 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 or caulking the injection unit 12 and the injection unit 22 by melting with a laser. As a result, the working fluid is stably held inside the closed space 2.

Next, the operation when the vapor chamber 1 is operated will be described. FIG. 16 schematically shows a state in which the vapor chamber 1 is arranged inside the portable terminal 40, which is a form of an electronic device. Here, since the vapor chamber 1 is arranged inside the housing 41 of the portable terminal 40, it is represented by a dotted line. Such a portable terminal 40 is configured to include a housing 41 containing various electronic components and a display unit 42 exposed so that an image can be seen to the outside through an opening of the housing 41. An electronic component 30 to be cooled by the vapor chamber 1 as one of these electronic components is arranged in the 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 which is an object to be cooled such as a CPU. 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.
Here, the vapor chamber 1 is an electronic component 30 so as to overlap one of the outer surface 10b and the outer surface 20b on XV-XV, which is the axis of symmetry shown in FIG. 15, when the vapor chamber 1 is viewed in a plan view. It is preferable to be attached so as to be arranged. More preferably, at this time, the electronic component 30 is also arranged so that the XV-XV are on the axis of symmetry (see FIG. 17). As a result, the steam flow path 4 becomes symmetrical with respect to the position of the heat source, the balance of self-excited vibration is maintained when the vapor chamber is operated, and the vibration is stabilized, so that high heat transport capacity can be exhibited.

FIG. 17 shows a diagram illustrating the behavior 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 electronic component 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 electronic component 30 in the sealed space 2 receives heat. The condensate that receives this heat absorbs the heat, evaporates, and vaporizes. This cools the electronic component 30.

The vaporized working fluid becomes steam, causes self-excited vibration in the steam flow path 4, and moves so as to vibrate in the steam flow path 4 as shown by the straight line arrow in FIG. 17. More specifically, the working fluid moves so as to vibrate in the steam flow path 4 formed by the inner liquid flow path portion 15, the steam flow path groove 16 parallel to the direction in which the inner flow path portion 25 extends, and the steam flow path groove 26. do. At the time of the movement, the first sheet 10 and the second sheet 20 are sequentially cooled while being deprived of heat. The first sheet 10 and the second sheet 20 that have taken heat from the steam transfer heat to the outer surface 10b, the housing of the portable terminal device in contact with the outer surface 20b, and the like, and finally the heat is released to the outside air. Then, the working fluid that has been deprived of heat while moving through the steam flow path 4 condenses and liquefies. Therefore, the condensed liquid is also present in the steam flow path 4, and the self-excited vibration is performed in the steam flow path 4 in a state where the vapor and the condensed liquid are alternately present.

A part of the condensed liquid generated in the steam flow path 4 moves to the condensed liquid flow path 3 from the liquid communication opening or the like. Since the condensed liquid flow path 3 of the present embodiment includes the liquid communication opening 14c and the liquid communication opening 15c, the condensed liquid passes through the liquid communication opening 14c and the liquid communication opening 15c to a plurality of condensed liquid flow paths. It is distributed to 3.

The condensate that has entered the condensate flow path 3 moves toward the electronic component 30 that is a heat source as shown by the dotted straight line arrow in FIG. 17 due to the capillary force of the condensate flow path. Then, it is vaporized again by the heat from the electronic component 30 which is a heat source, and the above is repeated.

As described above, according to the vapor chamber 1, the movement of the working fluid becomes smooth and good due to the self-excited vibration in the steam flow path and the high capillary force in the condensate flow path, and the heat transport amount is increased. Can be done. At this time, since each flow path has a structure symmetric with respect to XV-XV, which is the axis of symmetry, the balance of self-excited vibration is maintained when the vapor chamber is operated, and the self-excited vibration is stabilized, so that high heat is generated. The transportation capacity can be demonstrated more reliably.

FIG. 18 shows a diagram illustrating the vapor chamber 101 of the second embodiment. FIG. 18A shows a view of the second sheet 120 as viewed from the inner surface 20a side. FIG. 18B is a perspective view of the inside of the vapor chamber 101 in which the first sheet 10 and the second sheet 120 are combined, as in FIG. 15, and the enclosed space 102 (that is, the steam flow path and the condensate flow) is shown. It is the figure which showed the area (the region where a road was formed) by a solid line.

In the vapor chamber 101, a groove 122a is formed in the outer peripheral liquid flow path portion 24 of the second sheet 120 at a position just opposite to the portion where the injection groove 22a is provided. The groove 122a has the same shape as the portion where the injection groove 22a intersects the outer peripheral liquid flow path portion 24.

As a result, the vapor chamber 101 is considered to be in the closed space 102 surrounded by the joined portions, that is, in the range of the region provided with the condensate flow path 3 and the steam flow path 4, as in the case of the vapor chamber 1. When the shape is provided, the axis of symmetry is the axis parallel to the direction in which the condensate flow path 3 formed by the inner liquid flow path portion 15 and the inner liquid flow path portion 25 extends (XV in FIG. 18B). -XV) is considered to be a symmetrical shape.
In addition to this, the vapor chamber 101 is provided when considering the inside of the closed space 102 surrounded by the joined portion, that is, the range of the region provided with the condensate flow path 3 and the steam flow path 4. The shape to be formed is symmetric with the axis orthogonal to the direction in which the inner liquid flow path portion 15 and the condensed liquid flow path 3 formed by the inner liquid flow path portion 25 extend as the axis of symmetry (XVIII-XVIII in FIG. 18B). It is also shaped.

As a result, in addition to the effect described in the vapor chamber 1, the symmetry in the structure of the flow path provided in the closed space 102 of the vapor chamber 101 is further enhanced, and the dispersibility of the condensate when the vapor chamber is not operated is improved. Since it is raised and prevented from concentrating in one place, the vapor chamber is more reliably prevented from being destroyed even if the working fluid freezes and expands.
Therefore, even if the working fluid is used in an environment where the working fluid freezes, all of the thinning, heat transport capacity, and durability are satisfied.

FIG. 19 shows a diagram illustrating a modified example 101'of the vapor chamber 101 of the second embodiment. FIG. 19A shows a view of the second sheet 120'as viewed from the inner surface 20a side. FIG. 19 (b) is a perspective view of the inside of the vapor chamber 101'in which the first sheet 110 and the second sheet 120' are combined, as in the case of FIG. 18 (b), and the enclosed space 102'(that is, steam) is shown. The area where the flow path and the condensate flow path are formed) is shown by a solid line.

In the vapor chamber 101', the injection part 12 of the first sheet 110 and the injection part 22 of the second sheet 120' forming the injection flow path 5 are provided at two places. Specifically, such an injection unit 12 and an injection unit 22 are provided so as to be at exactly opposite positions (in this embodiment, on both end sides in the x direction).

As a result, in the vapor chamber 101', as in the vapor chamber 101, the structure in the enclosed space becomes symmetric with respect to the axes of symmetry XV-XV and XVIII-XVIII, so that the symmetry is enhanced and the vapor chamber 101 is enhanced. It has the same effect as. However, in this example, after the working fluid is sealed in the closed space 2, both injection flow paths 5 need to be closed.

FIG. 20 shows a diagram for explaining the vapor chamber 201 of the third embodiment. FIG. 20 (a) shows through the inside of the vapor chamber 201 in which the first sheet 210 and the second sheet 220 are combined, and the enclosed space 202 (that is, the vapor flow path and the condensate flow path are formed). The area) is shown by a solid line. FIG. 20 (b) is an enlarged view showing a part of the cut surface by XXb-XXb shown in FIG. 20 (a).

In the vapor chamber 201, a pillar protrusion 218 is arranged at the bottom of the steam flow path groove 16 of the first sheet 210, and a pillar protrusion 228 is arranged at the bottom of the steam flow path groove 26 of the second sheet 220. A plurality of pillar protrusions 218 and 228 are arranged at intervals in the direction in which the steam flow path grooves 16 and 26 extend, and in this embodiment, the plan view shape (shape from the viewpoint of FIG. 20A) is elliptical. Is.
When the first sheet 210 and the second sheet 220 having such pillar protrusions 218 and 228 are overlapped and joined to form a vapor chamber 201, the pillar protrusion 218 and the pillar protrusion 218 can be seen from FIG. 20 (b). The pillar protrusions 228 are also joined to form one pillar. As a result, this pillar functions as a pillar that supports the steam flow path 4 in the height direction, and it is possible to prevent the vapor chamber from being destroyed or deformed during manufacturing, use, freezing, and the like.

In this embodiment, the plan view shape of the pillar protrusions 218 and 228 is an elliptical shape, but the shape is not limited to this, and other shapes such as a circle, a triangle, a quadrangle, another polygon, and a wing shape may be used. You can also. Such a shape can be designed from the viewpoint of low flow path resistance and ease of fabrication.
Further, in this embodiment, the sizes of the upper and lower pillar protrusions are the same, but they may be different. When the sizes are different, it is possible to reduce the influence of the positional deviation at the time of joining.
Further, in the present embodiment, a plurality of pillar protrusions are arranged at intervals with respect to one steam flow path groove, but a single continuous pillar protrusion may be used.

FIG. 21 is a diagram illustrating the vapor chamber 301 of the fourth embodiment. FIG. 21 shows through the inside of the vapor chamber 301 in which the first sheet 310 and the second sheet 320 are combined, and shows the enclosed space 302 (that is, the region where the vapor flow path and the condensate flow path are formed). It is a figure shown by a solid line.

In the vapor chamber 301 of the present embodiment, the inner liquid flow path portion 15'and the inner liquid flow path portion 25' provided in the center are longitudinally longer than the other inner liquid flow path portions 15 and the inner liquid flow path portion 25. It extends and its both ends reach the outer peripheral liquid flow path portion 14 and the outer peripheral liquid flow path portion 24. As a result, as can be seen from FIG. 21, in the vapor chamber 301, two flow paths 4 _L1 in which both ends are communicated with each other are formed in the steam flow path 4. Even in such a form, the working fluid can self-excited and vibrate in the steam flow path 4 to increase the heat transport capacity.

22 to 29 are views for explaining the vapor chamber 401 of the fifth embodiment. FIG. 22 is an external perspective view of the vapor chamber 401, and FIG. 23 is an exploded perspective view of the vapor chamber 401.

As can be seen from FIGS. 22 and 23, the vapor chamber 401 has a first sheet 410, a second sheet 420, and a third sheet 430. Then, the first sheet 410, the second sheet 420, and the third sheet 430 are overlapped and joined (diffusion joining, brazing, etc.) between the first sheet 410 and the second sheet 420. A closed space 402 surrounded by the first sheet 410, the second sheet 420, and the third sheet 430 is formed (see FIG. 27), and the working fluid is sealed in the closed space 402.

In this embodiment, the first sheet 410 is a sheet-like member as a whole. The first sheet 410 is composed of flat surfaces on both the front and back surfaces, and has an inner surface 410a, an outer surface 410b opposite to the inner surface 410a, and a side surface 410c forming a thickness across the inner surface 410a and the outer surface 410b. Be prepared.

Further, the first sheet 410 includes a main body 411 and an injection unit 412. The main body 411 is a sheet-like portion forming a closed space in which the working fluid moves, and in this embodiment, it is a rectangle having an arc (so-called R) at an angle in a plan view.
The injection portion 412 is a portion for injecting the working fluid into the closed space formed by the first sheet 410, the second sheet 420, and the third sheet 430, and in this embodiment, one side which is a rectangular shape in a plan view of the main body 411. It is a sheet of a rectangular shape in a plan view protruding from. In this embodiment, the injection portion 412 of the first sheet 410 has a flat surface on both the inner surface 410a side and the outer surface 410b side.

The material constituting the first sheet 410 is not particularly limited, but may be a single material, and may be a composite material in which a plurality of different materials are laminated (a rolled bonding material called a "clad material"). Or, it may be a material laminated by plating).
When it is a single material, it is preferably a metal having high thermal conductivity. Examples thereof include copper and copper alloys. In particular, by using copper and a copper alloy, it becomes easy to manufacture a vapor chamber by etching and diffusion bonding while improving the heat transport capacity.
Further, in the case of a composite material, for example, a material having a high thermal conductivity on the inner surface 410a side and not reacting with a working fluid, and a material having a high strength on the outer surface 410b side can be applied. Examples thereof include a composite material in which the inner surface side is copper and the outer surface side is stainless steel, or a composite material in which the inner surface side is copper and the outer surface side is a copper alloy. According to this, it is possible to secure the strength such as deformation and breakage while maintaining high thermal performance.

In this embodiment, the second sheet 420 is a sheet-like member as a whole. The second sheet 420 is composed of flat surfaces on both the front and back surfaces, and has an inner surface 420a, an outer surface 420b opposite to the inner surface 420a, and a side surface 420c forming a thickness across the inner surface 420a and the outer surface 420b. Be prepared. The second sheet 420 also has a main body 421 and an injection unit 422.
The second sheet 420 can be considered in the same manner as the first sheet 410. However, the first sheet 410 and the second sheet 420 do not necessarily have to be the same material and have the same form, and may be configured differently.

In the present embodiment, the third sheet 430 is a sheet sandwiched and stacked between the first sheet 410 and the second sheet 420, and a structure for moving the working fluid is formed in the main body 431. FIG. 24 shows a plan view of the third sheet 430. FIG. 24A is a view of the surface overlapped with the second sheet 420, and FIG. 24B is a view of the surface overlapped with the first sheet 410. In addition, FIG. 25 shows a cut surface along the line shown by XXV-XXV in FIG. 24 (a), and FIG. 26 shows a cut surface along the line shown by XXVI-XXVI in FIG. 24 (a). ..

The third sheet 430 includes a main body 431 and an injection unit 432. The main body 431 is a sheet-like portion that forms a closed space in which the working fluid moves, and in this embodiment, it is a rectangle having an arc (so-called R) at an angle in a plan view.
The injection portion 432 is a portion for injecting the working fluid into the closed space formed by the first sheet 410, the second sheet 420, and the third sheet 430, and in this embodiment, one side of the main body 431 is a rectangular shape in a plan view. It is a sheet of a rectangular shape in a plan view protruding from. The injection portion 432 is formed with an injection groove 432a on the surface side overlapping with the first sheet 410. The injection groove 432a can be considered in the same manner as the above-mentioned injection groove 22a.

The main body 431 is provided with an outer peripheral joint portion 433, an outer peripheral liquid flow path portion 434, an inner liquid flow path portion 435, a steam flow path slit 436, and a steam flow path communication groove 437.

The outer peripheral joint portion 433 is a portion formed along the outer circumference of the main body 431. Then, one surface of the outer peripheral joint portion 433 overlaps the surface of the first sheet 410 and is joined (diffusion bonding, brazing, etc.), and the other surface overlaps the surface of the second sheet 420 and is joined (diffusion bonding, brazing, etc.). (Attached, etc.). As a result, a closed space 402 surrounded by the first sheet 410, the second sheet 420, and the third sheet 430 is formed, and the working fluid is sealed therein.
The outer peripheral joint portion 433 can be considered in the same manner as the outer peripheral joint portion 13 described above.

Further, of the outer peripheral joint portions 433 of the main body 431, holes 433a penetrating in the thickness direction (z direction) are provided at the four corners of the main body 431. The hole 433a functions as a positioning means when the first sheet 410 and the second sheet 420 are overlapped with each other.

The outer peripheral liquid flow path portion 434 functions as a liquid flow path portion, and is a portion constituting a part of the condensed liquid flow path 3 which is a flow path through which the working fluid is condensed and liquefied. The outer peripheral liquid flow path portion 434 is formed along the inside of the outer peripheral joint portion 433 of the main body 431, and is provided so as to form an annular shape along the outer periphery of the closed space 402. A liquid flow path groove 434a is formed on the surface of the outer peripheral liquid flow path portion 434 on the side facing the second sheet 420.
The outer peripheral liquid flow path portion 434 and the liquid flow path groove 434a provided therein can be considered in the same manner as the above-mentioned outer peripheral liquid flow path portion 14 and the liquid flow path groove 14a.

The inner liquid flow path portion 435 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. The inner liquid flow path portion 435 is formed inside the ring of the outer peripheral liquid flow path portion 434, which is an annular shape, in the main body 431. The inner liquid flow path portion 435 of the present embodiment is a rectangular portion of the main body 431 in a plan view and is a rod-shaped portion extending in a straight line in a direction parallel to the long side (x direction), and a plurality of (three in this embodiment) inner liquid flows. The road portions 435 are arranged at intervals in the direction parallel to the short side (y direction), and are arranged between the steam flow path slits 436.

A liquid flow path groove 435a, which is a linear groove parallel to the direction in which the inner liquid flow path portion 435 extends, is formed on the surface of the inner liquid flow path portion 435 on the side facing the second sheet 420. .. The inner liquid flow path portion 435 and the liquid flow path groove 435a can be considered in the same manner as the above-mentioned inner liquid flow path portion 15 and the liquid flow path groove 15a.

The vapor flow path slit 436 is a portion where the vapor-like and condensed liquid working fluids self-excited and vibrate, and is a slit constituting the vapor flow path 4. The steam flow path slit 436 is composed of a linear slit formed inside the ring of the outer peripheral liquid flow path portion 434, which is an annular shape, in the main body 431. Specifically, the steam flow path slit 436 of the present embodiment is formed between the adjacent inner liquid flow path portions 435 and between the outer peripheral liquid flow path portion 434 and the inner liquid flow path portion 435, and is a plan view of the main body 431. It is a rectangular slit extending in the direction parallel to the long side (x direction). Therefore, the steam flow path slit 436 penetrates the third sheet 430 in the thickness direction (z direction).
A plurality of (four in this embodiment) steam flow path slits 436 are arranged in a direction parallel to the short side (y direction). Therefore, as can be seen from FIG. 25, the third sheet 430 has a shape in which the outer peripheral liquid flow path portion 434, the inner liquid flow path portion 435, and the steam flow path slit 436 are alternately repeated in the y direction.

Such a steam flow path slit 436 can be considered in the same manner as the embodiment of the steam flow path 4 formed by combining the steam flow path groove 16 and the steam flow path groove 26 described above.

In this embodiment, the cross-sectional shape of the steam flow path slit 436 is a shape formed so that parts of elliptical arcs overlap each other, and the center in the thickness direction protrudes, but the shape is not limited to this, but is limited to squares, rectangles, and so on. Other forms such as a rectangle such as a trapezoid, a triangle, and a semicircle may be used.

The steam flow path communication groove 437 is a groove that forms a flow path for communicating a plurality of steam flow path slits 436. This makes it possible to balance the self-excited vibration of the working fluid generated in the steam flow path in the direction in which the inner liquid flow path portion 435 extends.
In addition, this makes it possible to equalize the working fluid in the steam flow path, transport the steam to a wider range, and efficiently utilize the condensed liquid flow path provided by many liquid flow path grooves 434a and 435a. I also do it.

Further, in the present embodiment, a plurality of inner liquid flow path portions 435 are connected by a steam flow path communication groove 437, and this is connected to the outer peripheral liquid flow path portion 434. As a result, the third sheet 430 is integrated. However, the means for integrating the third sheet 430 in this way is not limited to this, and other means may be used. For example, it may be arranged so as to cross the vapor flow path slit 436, and a piece for connecting the inner liquid flow path portion 435 and connecting the inner liquid flow path portion 434 to the outer peripheral liquid flow path portion 434 may be separately provided.

The steam flow path communication groove 437 of this embodiment is formed between both ends in the direction in which the inner liquid flow path portion 435 extends, both ends in the direction in which the steam flow path slit 436 extends, and the outer peripheral liquid flow path portion 434. There is. The steam flow path communication groove 437 may be able to communicate with the adjacent steam flow path slits 436, and its shape is not particularly limited, but the above-mentioned steam flow path communication groove 17 and the steam flow path communication groove 27 are not particularly limited. It can be considered in the same manner as the flow path formed by overlapping and.
In this embodiment, a hole 437a is provided in a part of the steam flow path communication groove 437 so as not to block the injection groove 432a.

The characteristic of the symmetry of the shape formed in the closed space 402 of the vapor chamber 401 by the configuration provided in the third sheet 430 described above can be considered in the same manner as the above-described aspect of each vapor chamber.

Such a third sheet 430 can be manufactured by etching individually for each side surface, simultaneous etching from both sides, press working, cutting processing, or the like.

27 to 29 show a diagram illustrating a structure when the first sheet 410, the second sheet 420, and the third sheet 430 are combined to form a vapor chamber 401. 27 shows a cut surface along the line shown by XXVII-XXVII in FIG. 22, and FIG. 28 shows an enlarged view of a part of FIG. 27. Further, FIG. 29 shows a cut surface along the line shown by XXIX-XXIX in FIG. 22.

As can be seen from FIGS. 22 and 27 to 29, the first sheet 410, the second sheet 420, and the third sheet 430 are arranged and joined so as to be overlapped with each other to form a vapor chamber 401. .. At this time, the inner surface 410a of the first sheet 410 and one surface of the third sheet 430 (the surface on the side where the liquid flow path groove 434a and the liquid flow path groove 435a are not arranged) are arranged so as to face each other, and the second sheet is arranged. The inner surface 420a of 420 and the other surface of the third sheet 430 (the surface on the side where the liquid flow path groove 434a and the liquid flow path groove 435a are arranged) are overlapped so as to face each other. Similarly, the injection portions 412, 422, and 432 of each sheet are also stacked.

As a result, a closed space 402 surrounded by the first sheet 410, the second sheet 420, and the third sheet 430 is formed between the first sheet 410 and the second sheet 420. A condensate flow path 3 and a vapor flow path 4 are formed here. The same concept as the vapor chamber described above can be applied to the morphology of the condensed liquid flow path 3 and the steam flow path 4 in the enclosed space 402.

1, 101, 201, 301, 401 Vapor chamber 2, 102, 202, 302, 402 Sealed space 3 Condensate flow path 4 Steam flow path 10, 110, 210, 310, 410 First sheet 10a Inner surface 10b Outer surface 10c Side surface 11 , Main body 12 Injection part 13 Outer peripheral joint part 14 Outer peripheral liquid flow path part 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, 120, 220, 320, 420 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 part 26 Steam flow path groove 27 Steam flow path Communication groove 430 Third sheet 436 Steam flow path slit

Claims (7)

A vapor chamber in which a closed space is formed between a plurality of sheets and a working fluid is sealed in the closed space.
In the closed space, a condensate flow path, which is a flow path through which the working fluid moves in a condensed state, and a flow path cross-sectional area larger than that of the condensate flow path, and the working fluid is in a vapor and condensate state. It is equipped with a steam flow path that self-excited and vibrates.
The condensate flow path is formed by arranging a plurality of linear condensate flow paths between the two vapor flow paths.
The plurality of steam channels are in communication with each other.
The structure in the region where the vapor flow path and the condensate flow path are arranged is configured to be symmetrical with respect to a line parallel to the condensate flow path arranged in a straight line. Vapor chamber. The vapor chamber according to claim 1, wherein the plurality of steam channels are all in communication with each other. The structure in the region where the vapor flow path and the condensate flow path are arranged is configured to be symmetrical with respect to a line orthogonal to the condensate flow path arranged in a straight line. The vapor chamber according to claim 1 or 2. The vapor chamber according to any one of claims 1 to 3, wherein an annular condensate flow path is provided along the edge of the enclosed space. The vapor chamber according to any one of claims 1 to 4, which has a thickness of 0.4 mm or less. With the housing
Electronic components placed inside the housing and
An electronic device comprising the vapor chamber according to any one of claims 1 to 5, which is arranged in direct contact with or in contact with the electronic component via another member. The sixth aspect of claim 6, wherein the electronic component is arranged at a position overlapping the axis by a line parallel to the linearly arranged condensate flow path of the vapor chamber when the vapor chamber is viewed in a plan view. Electronic equipment.

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