JP2023015091A - Vapor chamber, electronic apparatus, sheet for vapor chamber, and manufacturing method of vapor chamber sheet and vapor chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vapor chamber having high heat transport capacity and high productivity, and an electronic apparatus including the vapor chamber, a sheet for the vapor chamber, and a manufacturing method of the sheet for vapor chamber and the vapor chamber.

SOLUTION: In a vapor chamber, a plurality of first flow channels and second flow channels disposed between the plurality of adjacent first flow channels are provided in a sealed space, and when an average flow channel cross-sectional area of the adjacent two first flow channels is Ag, and an average flow channel cross-sectional area of the plurality of second flow channels disposed between the adjacent first flow channels is Al, Al is 0.5 times or less of Ag at least partially, and the first flow channel has a step on a position where the second flow channel is disposed in a thickness direction, of its inner surface.

SELECTED DRAWING: Figure 21

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present disclosure relates to a vapor chamber that transports heat by circulating a working fluid enclosed in a closed space with a phase change.

The amount of heat generated from electronic components such as CPUs (Central Processing Units) installed in personal computers and mobile terminals such as mobile phones and tablet terminals tends to increase due to improvements in information processing capacity, and cooling technology is important. be. Heat pipes are well known as means for such cooling. This is to cool the heat source by transporting the heat from the heat source to other parts and diffusing it with the working fluid enclosed in the pipe.

On the other hand, in recent years, portable terminals and the like have become particularly thin, and a thinner cooling means than the conventional heat pipe has become necessary. In response to this, for example, a vapor chamber as described in Patent Document 1 has been proposed.

A vapor chamber is a device that applies the concept of heat transport using a heat pipe to a flat plate member. That is, in the vapor chamber, a working fluid is enclosed between flat plates that are arranged facing each other and joined together, and the working fluid circulates with a phase change, thereby transporting and diffusing the heat in the heat source. Cool the heat source.

More specifically, there is a form in which a vapor channel and a condensate channel are provided between opposing flat plates of the vapor chamber, and the working fluid is sealed therein. When the vapor chamber is placed near the heat source, the working fluid receives heat from the heat source and evaporates in the vicinity of the heat source, becomes gas (vapor), and moves through the vapor channel. This allows the heat from the heat source to be smoothly transported away from the heat source, thereby cooling the heat source.
The gaseous working fluid that has transported the heat from the heat source moves to a position away from the heat source, where it is cooled and condensed by the heat being absorbed by the surroundings, and undergoes a phase change to a liquid state. The phase-changed liquid working fluid passes through the condensate flow path, returns to the position of the heat source, receives heat from the heat source, and evaporates to change to a gaseous state.
The heat generated from the heat source is transported to a position away from the heat source by the circulation as described above, and the heat source is cooled.

Japanese Unexamined Patent Application Publication No. 2007-212028

An object of the present disclosure is to provide a vapor chamber that has high heat-transporting capability and excellent productivity. Also provided are an electronic device including the vapor chamber, a vapor chamber sheet, and a method for manufacturing the vapor chamber sheet and the vapor chamber.

One aspect of the present disclosure is a vapor chamber having a closed space in which a working fluid is enclosed, wherein the closed space includes a plurality of first flow paths, a plurality of first flow paths, and adjacent first flow paths. a second channel provided between the channels, wherein the average channel cross-sectional area of two adjacent first channels is _Ag , and a plurality of channels arranged between the adjacent first channels When the average cross-sectional area of the second flow channel is A _l , A _l is 0.5 times or less than A _g in at least a part of the first flow channel. The vapor chamber has a step at the position where the second flow path is arranged in the thickness direction of the vapor chamber.

According to the aspect of the present disclosure, it is possible to provide a vapor chamber with enhanced heat transport capability.

FIG. 1 is a perspective view of a vapor chamber. FIG. 2 is an exploded perspective view of the vapor chamber. FIG. 3 is a perspective view of the first seat. FIG. 4 is a plan view of the first sheet. FIG. 5 is a cut surface of the first sheet. FIG. 6 is another cut surface of the first sheet 10. FIG. FIG. 7 is another cut surface of the first sheet 10. FIG. FIG. 8 is a partially enlarged view of the outer peripheral liquid flow path in plan view. FIG. 9 is a plan view of another example of the outer peripheral liquid flow path portion, and is a partially enlarged view. FIG. 10 is a plan view of another example of the outer peripheral liquid flow path portion, showing a partially enlarged view. FIG. 11 is a plan view of another example of the outer peripheral liquid flow path portion, showing a partially enlarged view. FIG. 12 is a plan view of another example of the outer peripheral liquid flow path portion, showing a partially enlarged view. FIG. 13 shows an example in which the cross-sectional shape of the liquid flow channel is semi-elliptical. FIG. 14 is a cross-sectional view focusing on the inner liquid flow path portion. FIG. 15 is a partially enlarged view of the inner liquid flow path section in plan view. FIG. 16 shows an example in which the cross-sectional shape of the steam channel groove is semicircular. FIG. 17 is a perspective view of the second seat. FIG. 18 is a plan view of the second sheet. FIG. 19 is a cut surface of the second sheet. FIG. 20 is a cut surface of the second sheet. FIG. 21 is a cross section of the vapor chamber. 22 is an enlarged view of a part of FIG. 21. FIG. FIG. 23 is a further enlarged view of part of FIG. FIG. 24 is a further enlarged view of part of FIG. FIG. 25 is another cross section of the vapor chamber 1. FIG. FIG. 26 is a diagram schematically showing a portable terminal (electronic device) 40. As shown in FIG. FIG. 27 is a diagram for explaining the flow of working fluid. FIG. 28 is a diagram illustrating the configuration of another example of the vapor chamber. FIG. 29 is a diagram illustrating another example of the vapor chamber. FIG. 30 is a diagram illustrating the configuration of another example of the vapor chamber. FIG. 31 is a diagram illustrating the configuration of another example of the vapor chamber. FIG. 32 is a diagram illustrating the configuration of another example of the vapor chamber. FIG. 33 is a diagram for explaining the configuration of another example of the vapor chamber.

Hereinafter, the present disclosure will be described based on the forms shown in the drawings. In the drawings shown below, the sizes and ratios of members may be changed or exaggerated for clarity. In addition, for the sake of visibility, parts that are not required for explanation and repetitive symbols may be omitted.

FIG. 1 shows an external perspective view of a vapor chamber 1 according to one embodiment, and FIG. 2 shows an exploded perspective view of the vapor chamber 1. As shown in FIG. Directional arrows (x, y, z) are also shown in these figures and each figure shown below for convenience as needed. Here, the in-plane xy direction is the plate surface direction of the flat vapor chamber 1, and the z direction is the thickness direction.

The vapor chamber 1 of this embodiment has a first sheet 10 and a second sheet 20 as can be seen from FIGS. As will be described later, the first sheet 10 and the second sheet 20 are overlapped and bonded (diffusion bonding, brazing, etc.), so that there is a gap between the first sheet 10 and the second sheet 20. A closed space 2 is formed in (for example, see FIG. 21), and the working fluid is enclosed in this closed space 2 .

In this embodiment, the first sheet 10 is a sheet-like member as a whole. 3 is a perspective view of the first sheet 10 viewed from the inner surface 10a side, and FIG. 4 is a plan view of the first sheet 10 viewed from the inner surface 10a side. 5 shows a cut surface of the first sheet 10 when cut along VV in FIG.
The first sheet 10 has an inner surface 10a, an outer surface 10b opposite to the inner surface 10a, and a side surface 10c connecting the inner surface 10a and the outer surface 10b to form a thickness, and the working fluid flows back to the inner surface 10a side. A pattern for the flow path is formed. As will be described later, the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20 are overlapped so as to face each other to form a hollow portion, in which a working fluid is enclosed to form a sealed space. 2.

Such a first sheet 10 comprises a main body 11 and an injection part 12 . The main body 11 has a sheet-like shape that forms a portion through which the working fluid circulates, and in this embodiment is rectangular with arcs (so-called R) formed at the corners in a plan view.
However, the main body 11 of the first sheet 10 is not only rectangular like this embodiment, but also circular, elliptical,
It may be triangular, other polygonal shapes, and shapes with bends, such as L-shapes, T-shapes, crank shapes, and the like. Moreover, it is also possible to adopt a shape in which at least two of these are combined.

The injection part 12 is a part that injects a working fluid into a hollow part formed by the first sheet 10 and the second sheet 20 to form a closed space 2 (see, for example, FIG. 21). It is in the shape of a square sheet in plan view, protruding from one side of the rectangle in view. 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.

Although the thickness of the first sheet 10 is not particularly limited, it is preferably 1.0 mm or less, may be 0.75 mm or less, or may be 0.5 mm or less. On the other hand, the thickness is preferably 0.02 mm or more, may be 0.05 mm or more, or may be 0.1 mm or more. The thickness range may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the thickness range may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
As a result, it is possible to increase the number of situations in which the thin vapor chamber can be applied.

Moreover, although the material constituting the first sheet 10 is not particularly limited, it is preferably a metal with high thermal conductivity. This includes, for example, copper and copper alloys.
However, it does not necessarily have to be a metal material, and ceramics such as AlN, Si ₃ N ₄ or Al ₂ O ₃ and resins such as polyimide and epoxy are also possible.
In addition, one sheet in which two or more kinds of materials are laminated may be used, and the materials may differ depending on the part.

A structure is formed on the inner surface 10a side of the main body 11 to allow the working fluid to flow back. Specifically, on the inner surface 10a side of the main body 11, an outer peripheral joint portion 13, an outer peripheral liquid channel portion 14, an inner liquid channel portion 15, a steam channel groove 16, and a steam channel communication groove 17 are provided. ing.

The outer peripheral joint portion 13 is a surface formed along the outer periphery of the main body 11 on the inner surface 10 a side of the main body 11 . A hollow portion is formed between the first sheet 10 and the second sheet 20 by joining (diffusion bonding, brazing, etc.) the outer peripheral joint portion 13 to overlap the outer peripheral joint portion 23 of the second sheet 20 . , and a closed space 2 is formed by enclosing a working fluid therein.
The width of the outer peripheral joint portion 13 indicated by A in FIGS. 4 and 5 (the width in the direction orthogonal to the direction in which the outer peripheral joint portion 13 extends and the width at the joint surface with the second sheet 20) is appropriately adjusted as necessary. Although it can be set, the width A is preferably 3 mm or less, may be 2.5 mm or less, or may be 2.0 mm or less. If the width A is larger than 3 mm, the internal volume of the closed space becomes small, and there is a possibility that the steam flow path and the condensate flow path cannot be secured sufficiently. On the other hand, the width A is preferably 0.2 mm or more, may be 0.6 mm or more, or may be 0.8 mm or more. If the width A is less than 0.2 mm, there is a risk that the bonding area will be insufficient when the first sheet and the second sheet are misaligned during bonding. The range of width A may be determined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of the width A may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.

Further, holes 13a are provided in the four corners of the main body 11 in the outer peripheral joint portion 13 so as to penetrate in the thickness direction (z direction). This hole 13a functions as positioning means when the second sheet 20 is superimposed.

The peripheral liquid flow path portion 14 functions as a liquid flow path portion and is a portion that constitutes a part of the condensed liquid flow path 3, which is a second flow path through which the working fluid condenses and liquefies. FIG. 6 shows the portion indicated by the arrow VI in FIG. 5, and FIG. 7 shows the cut surface of the site cut at VII-VII in FIG. The cross-sectional shape of the outer peripheral liquid flow path portion 14 appears in each figure. 8 shows an enlarged plan view of the outer peripheral liquid flow path portion 14 as seen from the direction indicated by the arrow VIII in FIG.

As can be seen from these drawings, the outer peripheral liquid flow path portion 14 is formed along the inner side of the outer peripheral joint portion 13 of the inner surface 10 a of the main body 11 and provided along the outer periphery of the closed space 2 . Further, in the outer peripheral liquid channel portion 14, liquid channel grooves 14a, which are a plurality of grooves extending along the outer peripheral direction of the main body 11, are formed. They are arranged at predetermined intervals in a direction different from the extending direction. Therefore, as can be seen from FIGS. 6 and 7, in the cross section of the outer peripheral liquid flow path portion 14, on the inner surface 10a side, the liquid flow path groove 14a, which is a concave portion, and the convex portion 14b between the liquid flow path grooves 14a are uneven. is repeating.
Here, since the liquid channel groove 14a is a groove, in its cross-sectional shape, it has a bottom portion on the side of the outer surface 10b and an opening on the side of the inner surface 10a opposite to the bottom portion.

In addition, by providing a plurality of liquid flow grooves 14a in this way, the depth and width of each liquid flow groove 14a can be reduced, and the condensate liquid flow path 3 (see FIG. 23), which is the second flow path, can be reduced. ) can be reduced to utilize a large capillary force. On the other hand, by providing a plurality of liquid flow grooves 14a, the total flow path cross-sectional area of the condensate flow path 3 as a whole can be ensured to have a suitable size, and the required flow rate of the condensate can be flowed.

Further, in the outer peripheral liquid flow path portion 14, as can be seen from FIG. 8, the adjacent liquid flow path grooves 14a are communicated with each other by the communication openings 14c at predetermined intervals. This promotes equalization of the amount of condensed liquid among the plurality of liquid passage grooves 14a, allows the condensed liquid to flow efficiently, and enables smoother return of the working fluid.
In this embodiment, as shown in FIG. 8, the communication openings 14c are arranged so as to face each other at the same position in the extending direction of the liquid flow channel 14a across the groove of one liquid flow channel 14a. However, the present invention is not limited to this. For example, as shown in FIG. 9, the communication openings 14c are arranged at different positions in the direction in which the liquid flow channel 14a extends across the groove of one liquid flow channel 14a. may be That is, the protrusions 14b and the communication openings 14c may be alternately arranged along the direction orthogonal to the direction in which the liquid channel grooves 14a extend.

In addition, for example, it is possible to adopt a form as shown in FIGS. 10 to 12. FIG. 10 to 12 show one condensate flow path 14a, two protrusions 14b sandwiching this, and one communication opening 14c provided in each protrusion 14b from the same viewpoint as in FIG. Illustrated. In both cases, the shape of the wall 14b is different from the example in FIG. 8 from the viewpoint (planar view).
That is, in the convex portion 14b shown in FIG. 8, the width of the end portion where the communicating opening portion 14c is formed is the same as that of the other portion and is constant. 10 to 12, the width at the end where the communication opening 14c is formed is smaller than the maximum width of the projection 14b. . More specifically, in the example of FIG. 10, the corners are arc-shaped at the end and the width of the end is reduced by forming an R at the corner. In FIG. 11, the end is semicircular. FIG. 12 shows an example in which the width of the end portion is reduced as a result, and the end portion is tapered to a sharp point.

As shown in FIGS. 10 to 12, the width of the end portion of the projection 14b where the communication opening 14c is formed is smaller than the maximum width of the projection 14b. It becomes easier for the working fluid to move through the openings 14c, and the movement of the working fluid to the adjacent condensate flow path 3 becomes easier.

It is preferable that the outer peripheral liquid flow path portion 14 of the present embodiment having the above configuration further has the following configuration.
The width of the outer peripheral liquid channel portion 14 indicated by B in FIGS. 4 to 7 (the width in the direction in which the liquid channel portions 14a are arranged and the width at the joint surface with the second sheet 20) is the entire vapor chamber. Although the width B can be appropriately set depending on the size and the like, the width B is preferably 3.0 mm or less, may be 1.5 mm or less, or may be 1.0 mm or less. If the width B exceeds 3.0 mm, there is a possibility that a sufficient space for the inner condensate flow path and steam flow path cannot be secured. On the other hand, the width B is preferably 0.1 mm or more, may be 0.2 mm or more, or may be 0.4 mm or more. If the width B is less than 0.1 mm, there is a possibility that a sufficient amount of condensate may not be obtained to circulate outside. The range of the width B may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of the width B may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
The width B is preferably different from the width S (see FIG. 19) of the outer peripheral liquid flow path portion 24 of the second sheet. That is, when the first sheet 10 and the second sheet 20 are combined, the vapor flow path 4, which is the first flow path, has a condensing flow path, which is the second flow path, in the thickness direction of the vapor chamber. A step is provided at the position where the liquid flow path is arranged.
As a result, even if the first sheet 10 and the second sheet 20 are joined together, even if there is a slight misalignment, the joining accuracy can be moderated. Therefore, accuracy control can be relaxed during production, and productivity, such as yield improvement, can be enhanced.
Further, when the width B is made larger than the width S as in the present embodiment, the opening of the liquid flow channel groove 14a in at least a part of the outer peripheral liquid flow channel portion 14 is the same as the vapor flow channel 4, as will be described later. The condensate can easily enter from here, so that the condensate can be circulated more smoothly.

Regarding the liquid flow channel 14a, the groove width indicated by C in FIGS. 6 and 8 (the size in the direction in which the liquid flow channel 14a is arranged, the width at the opening surface of the groove) is 1000 μm or less. Preferably, it may be 500 μm or less, or 200 μm or less. On the other hand, the width C is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. The range of width C may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of the width C may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
Moreover, the depth of the groove indicated by D in FIGS. 6 and 7 is preferably 200 μm or less, may be 150 μm or less, or may be 100 μm or less. On the other hand, the depth D is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. The range of depth D may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of depth D may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
By configuring as described above, the capillary force of the condensate flow path required for reflux can be exerted more strongly.

From the viewpoint of exerting the capillary force of the condensate flow channel more strongly, the aspect ratio (horizontal-to-horizontal ratio) of the cross section of the flow channel, which is the value obtained by dividing the width C by the depth D, is preferably greater than 1.0. This ratio may be 1.5 or more, or 2.0 or more. Alternatively, the aspect ratio may be less than 1.0. This ratio may be 0.75 or less, or may be 0.5 or less.
Among them, from the viewpoint of manufacturing, C is preferably larger than D, and from such a viewpoint, the aspect ratio is preferably larger than 1.3.

In this embodiment, the cross-sectional shape of the liquid flow channel 14a is rectangular, but is not limited to this, and may be a square such as a square, a trapezoid, a triangle, a semicircle, a bottom of a semicircle, a semiellipse, or a shape selected from these. The shape may be a combination of a plurality of FIG. 13 shows an example in which the liquid flow channel 14a is semielliptical. With this shape, etching can be used to fabricate liquid flow channels.
Among these, the rectangular shape is preferable because surface tension tends to work due to the presence of corners formed by internal corners, and the liquid tends to flow smoothly due to capillary force.

Also, the pitch between adjacent liquid flow grooves 14a in a plurality of liquid flow grooves 14a is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. On the other hand, the pitch is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. This pitch range may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the pitch range may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
As a result, it is possible to increase the density of the condensate flow path and prevent the flow path from collapsing due to deformation during bonding or assembly.

Regarding the communication opening 14c, the size of the opening along the extending direction of the liquid flow channel 14a indicated by E in FIG. may On the other hand, the size E is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. The range of magnitude E may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of magnitude E may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.

In addition, the pitch between the adjacent communication openings 14c in the direction in which the liquid channel grooves 14a extend, which is indicated by F in FIG. . On the other hand, this pitch is preferably 60 μm or more, may be 110 μm or more, or may be 140 μm or more. This pitch range may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the pitch range may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.

Returning to FIGS. 3 to 5, the inner liquid flow path section 15 will be described. The inner liquid flow path portion 15 also functions as a liquid flow path portion, and constitutes a part of the condensed liquid flow path 3 as a second flow path through which the working fluid condenses and liquefies. FIG. 14 shows the portion indicated by VI in FIG. This figure also shows the cross-sectional shape of the inner liquid flow path portion 15 . 15 shows an enlarged plan view of the inner liquid flow path portion 15 viewed from the direction indicated by the arrow XII in FIG.

As can be seen from these figures, the inner liquid flow path portion 15 is formed inside the annular ring of the outer peripheral liquid flow path portion 14 on the inner surface 10a of the main body 11 . As can be seen from FIGS. 3 and 4, the inner liquid flow path portion 15 of the present embodiment is a rectangular wall extending in the direction (x direction) parallel to the long side of the main body 11 in plan view. ) are arranged at predetermined intervals in a direction (y-direction) parallel to the short side.
Each inner liquid channel portion 15 is provided with a liquid channel groove 15a which is a groove parallel to the direction in which the inner liquid channel portion 15 extends. They are arranged at predetermined intervals in a direction different from the extending direction. Therefore, as can be seen from FIGS. 5 and 14, in the cross section of the inner liquid flow path portion 15, the liquid flow path groove 15a, which is a concave portion, and the convex portion 15b between the liquid flow path grooves 15a are uneven on the inner surface 10a side. is repeated.
Here, since the liquid channel groove 15a is a groove, its cross-sectional shape has a bottom portion on the side of the outer surface 10b and an opening on the side of the inner surface 10a on the opposite side facing the bottom portion.

By providing a plurality of liquid flow channels 15a in this manner, the depth and width of each liquid flow channel 15a can be reduced, and the condensate flow channel 3 (see FIG. 23) as the second flow channel can be formed. A large capillary force can be utilized by reducing the channel cross-sectional area. On the other hand, by providing a plurality of liquid flow grooves 15a, the total flow path cross-sectional area of the condensate flow path 3 as a whole can be ensured to have a suitable size, and the necessary flow rate of the condensate can be flowed.

Further, as can be seen from FIG. 15, the adjacent liquid flow channels 15a are communicated with each other by the communication openings 15c at predetermined intervals. This promotes equalization of the amount of condensed liquid among the plurality of liquid passage grooves 15a and allows the condensed liquid to flow efficiently, thereby enabling smooth circulation of the working fluid.
Similarly to the communication opening 14c, the communication opening 15c also follows the example shown in FIG. may be alternately arranged.
Further, the shape of the communication opening 15c and the wall 15b may be similar to those of FIGS. 10 to 12. FIG.

It is preferable that the inner liquid flow path portion 15 of the present embodiment having the above configuration further has the following configuration.
4, 5, and 14 (the size in the direction in which the inner liquid channel portion 15 and the steam channel grooves 16 are arranged, and The width at the bonding surface) is preferably 3000 μm or less, may be 1500 μm or less, or may be 1000 μm or less. On the other hand, the width G is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. The range of width G may be determined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of the width G may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
The width G is preferably different from the width T (see FIG. 19) of the inner liquid flow path portion 25 of the second sheet. As a result, even if the first sheet 10 and the second sheet 20 are joined together, even if there is a slight misalignment, the joining accuracy can be moderated. Therefore, accuracy control can be relaxed during production, and productivity, such as yield improvement, can be enhanced.
Further, in this embodiment, the width G is made larger than the width T, and according to this, as will be described later, at least a part of the inner liquid flow path portion 15 has an opening of the liquid flow path groove 15a which is the vapor flow path. 4 can be contained and arranged so as to form a part of the condensate, and the condensate can easily enter from here, so that the condensate can be recirculated more smoothly.

Also, the pitch of the plurality of inner liquid flow path portions 15 is preferably 4000 μm or less, may be 3000 μm or less, or may be 2000 μm or less. On the other hand, this pitch is preferably 200 μm or more, may be 400 μm or more, or may be 800 μm or more. This pitch range may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the pitch range may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
As a result, the flow path resistance of the steam flow path can be lowered, and the movement of the steam and the reflux of the condensate can be performed in a well-balanced manner.

Regarding the liquid flow channel 15a, the groove width indicated by H in FIGS. 14 and 15 (the size in the direction in which the liquid flow channel 15a is arranged, the width at the opening surface of the groove) is 1000 μm or less. Preferably, it may be 500 μm or less, or 200 μm or less. On the other hand, the width H is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. The range of width H may be determined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of the width H may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
The depth of the groove indicated by J in FIG. 14 is preferably 200 μm or less, and may be 150 μm or less, or may be 100 μm or less. On the other hand, the depth J is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. The range of depth J may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of depth J may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
As a result, the capillary force of the condensate flow path required for reflux can be strongly exerted.

From the viewpoint of exerting the capillary force of the flow channel more strongly, the aspect ratio (vertical-to-horizontal ratio) of the cross section of the flow channel, which is the value obtained by dividing the width H by the depth J, is preferably greater than 1.0. It may be 1.5 or more, or 2.0 or more. Alternatively, it may be less than 1.0, 0.75 or less, or 0.5 or less.
Among them, the width H is preferably larger than the depth J from the viewpoint of manufacturing, and the aspect ratio is preferably larger than 1.3 from this viewpoint.

In addition, although the cross-sectional shape of the liquid flow channel 15a is rectangular in this embodiment, it is not limited to this, and may be a square such as a square, a trapezoid, a triangle, a semi-circle, a semi-circular bottom, a semi-elliptical bottom, or a combination thereof. It may also be in the shape of The cross-sectional shape of the liquid flow channel 15a can also be made semielliptical following the example of FIG. With this shape, etching can be used to fabricate liquid flow channels.
Among them, the rectangular shape is preferable because surface tension tends to work due to the presence of corners formed by internal corners, and capillary force tends to facilitate the circulation of the liquid.

Also, the pitch between adjacent liquid flow grooves 15a in a plurality of liquid flow grooves 15a is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. On the other hand, this pitch is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. This pitch range may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the pitch range may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
As a result, it is possible to increase the density of the condensate flow path and prevent the flow path from collapsing due to deformation during bonding or assembly.

Regarding the communication opening 15c, the size of the communication opening along the direction in which the liquid flow channel 15a extends, which is indicated by K in FIG. There may be. On the other hand, the size K is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. The range of magnitude K may be determined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of magnitude K may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
Also, the pitch between the adjacent communication openings 15c in the direction in which the liquid flow channel 15a extends, indicated by L in FIG. good too. On the other hand, this pitch is preferably 60 μm or more, may be 110 μm or more, or may be 140 μm or more. This pitch range may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, this pitch range may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.

The liquid flow grooves 14a and the liquid flow grooves 15a of the present embodiment described above are arranged in parallel with each other at regular intervals. The pitch may vary, and the grooves do not have to be parallel.

Next, the steam channel groove 16 will be described. The vapor channel groove 16 is a portion through which the vapor obtained by evaporating the working fluid passes, and constitutes a part of the vapor channel 4 which is the first channel. FIG. 4 shows the shape of the steam flow channel groove 16 in plan view, and FIG. 5 shows the cross-sectional shape of the steam flow channel groove 16 .
As can be seen from these figures, the steam channel groove 16 is formed by a groove formed inside the annular ring of the outer peripheral liquid channel portion 14 in the inner surface 10 a of the main body 11 . Specifically, the steam flow channel grooves 16 of this embodiment are formed between the adjacent inner liquid flow channel portions 15 and between the outer peripheral liquid flow channel portion 14 and the inner liquid flow channel portion 15, and are It is a rectangular groove extending in a direction (x direction) parallel to the long side. A plurality of (four in this embodiment) steam flow channels 16 are arranged in a direction (y direction) parallel to the same short side. Therefore, as can be seen from FIG. 5, the first sheet 10 repeats unevenness in the y direction, in which the walls, which are the outer peripheral liquid flow path portion 14 and the inner liquid flow path portion 15, are convex, and the vapor flow channel grooves 16 are concave. It has a well-defined shape.
Here, since the steam channel groove 16 is a groove, in its cross-sectional shape, it has an opening on the bottom on the side of the outer surface 10b and on the side of the inner surface 10a on the opposite side facing the bottom.

The steam flow channel groove 16 having such a configuration preferably further has the following configuration.
The width of the steam channel groove 16 indicated by M in FIGS. The widths C and H of the liquid flow channel 14a and the liquid flow channel 15a are formed larger than the widths C and H, and are preferably 2000 μm or less, may be 1500 μm or less, or may be 1000 μm or less. On the other hand, the width M is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. The range of width M may be determined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of the width M may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
The pitch of the vapor channel grooves 16 is usually determined by the pitch of the inner liquid channel portion 15 .

On the other hand, the depth of the steam channel groove 16 indicated by N in FIG. 5 is at least greater than the depth D and the depth J of the liquid channel groove 14a and the liquid channel groove 15a, and is 300 μm or less. is preferably 200 μm or less, or 100 μm or less. On the other hand, the depth N is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of depth N may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of depth N may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
By making the cross-sectional area of the steam flow channel larger than that of the liquid flow channel in this way, it is possible to smoothly circulate the steam whose volume is larger than that of the condensate due to the nature of the working fluid.

In this embodiment, the cross-sectional shape of the steam flow channel groove 16 is rectangular, but is not limited to this, and is not limited to rectangular, triangular, semi-circular, semi-circular or semi-elliptical bottoms, or any combination thereof. It may also be in the shape of FIG. 16 shows an example in which the steam channel groove 16 is semicircular. This shape allows etching to be used to create vapor flow channels.
By reducing the flow resistance of steam in the steam flow path, the working fluid can be smoothly circulated, so the cross-sectional shape of the flow path can be determined from this point of view.

In this embodiment, an example in which one vapor flow channel groove 16 is formed between adjacent inner liquid flow channel portions 15 has been described. A configuration in which the steam channel grooves are arranged side by side may also be used.
Moreover, as long as the second sheet 20 is formed with the steam flow channel, the first sheet 10 may not be partially or wholly formed with the steam flow channel.

The steam flow channel communication groove 17 is a groove that allows the plurality of steam flow channel grooves 16 to communicate with each other. As a result, the vapor in the plurality of vapor passage grooves 16 is equalized, the vapor is conveyed over a wider range, and many liquid passage grooves 14a and 15a can be efficiently used. Reflux can be made smoother.

As can be seen from FIGS. 3 and 4, the steam channel communication groove 17 of the present embodiment is located between both ends in the extending direction of the inner liquid channel portion 15 and the steam channel groove 16 and the outer peripheral liquid channel portion 14. is formed in 7 shows a cross section perpendicular to the communicating direction of the steam channel communicating groove 17. As shown in FIG. In FIGS. 2 to 4, the boundary between the steam channel groove 16 and the steam channel communication groove 17 is indicated by a dotted line for easy viewing. However, this line is not based on the shape but is an imaginary line provided for ease of viewing.

The steam channel communication groove 17 may be formed so as to communicate with the adjacent steam channel grooves 16, and its shape is not particularly limited, but it may have the following configuration, for example. .
The width of the steam passage communication groove 17 indicated by P in FIGS. 4 and 7 (the width in the direction orthogonal to the communication direction and the width of the opening of the groove) is preferably 1000 μm or less, and preferably 750 μm or less. It may be 500 μm or less. On the other hand, the width P is preferably 100 μm or more, may be 150 μm or more, or may be 200 μm or more. The range of width P may be determined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of the width P may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
Moreover, the depth of the steam flow channel communication groove 17 indicated by Q in FIG. 7 is preferably 300 μm or less, and may be 225 μm or less, or may be 150 μm or less. On the other hand, the depth Q is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of depth Q may be determined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of depth Q may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values. Among them, it is preferable that the depth is the same as the depth N of the steam channel groove 16 . This facilitates manufacturing.

In this embodiment, the cross-sectional shape of the steam flow channel communication groove 17 is rectangular, but is not limited to this, and is not limited to rectangular, triangular, semicircular, bottom semicircular, semielliptical, or any of these. A plurality of combinations may be used. It can be semi-circular, following the example of FIG. With this shape, it is possible to fabricate a vapor passage communication groove using etching.
Since the steam flow channel communication groove can cause smooth circulation of the working fluid by reducing the flow resistance of the steam, the shape of the cross section of the flow channel can also be determined from this point of view.

Next, the second seat 20 will be explained. In this embodiment, the second sheet 20 is also a sheet-like member as a whole. 17 is a perspective view of the second sheet 20 viewed from the inner surface 20a side, and FIG. 18 is a plan view of the second sheet 20 viewed from the inner surface 20a side. 19 shows a cut surface of the second sheet 20 when cut along XVI-XVI in FIG. 18. As shown in FIG. FIG. 20 shows a cut surface of the second sheet 20 cut along XVII-XVII in FIG.
The second sheet 20 has an inner surface 20a, an outer surface 20b opposite to the inner surface 20a, and a side surface 20c connecting the inner surface 20a and the outer surface 20b to form a thickness. is formed. As will be described later, the inner surface 20a of the second sheet 20 and the inner surface 10a of the first sheet 10 are overlapped so as to face each other to form a hollow portion, and a working fluid is sealed therein to seal the hollow portion. becomes space 2.

The second seat 20 has a main body 21 and an injection part 22 . The main body 21 is a sheet-like portion that forms a portion through which the working fluid circulates, and in this embodiment is rectangular with arcs (so-called R) formed at the corners in a plan view.
However, the second sheet 20 is not only rectangular as in this embodiment, but also circular, elliptical, triangular, other polygonal, and shapes having bent portions, such as L-shaped, T-shaped, crank-shaped, and the like. may be Moreover, it is also possible to adopt a shape in which at least two of these are combined.

The injection part 22 is a part that injects and seals the working fluid into the hollow part formed by the first sheet 10 and the second sheet 20 to form the sealed space 2 (see FIG. 21). 21 is a rectangular sheet in plan view and protrudes from one side of the plan view rectangle. In this embodiment, an injection groove 22a is formed on the inner surface 20a side of the injection portion 22 of the second sheet 20, and the side surface 20c of the second sheet 20 communicates with the inside of the main body 21 (the portion to be the hollow portion). ing.
The thickness and constituent material of the second sheet 20 can be considered in the same manner as the first sheet 10 . However, the first sheet 10 and the second sheet 20 do not necessarily have the same thickness and material.

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

The outer peripheral joint portion 23 is a surface formed along the outer periphery of the main body 21 on the inner surface 20 a side of the main body 21 . This outer peripheral joint portion 23 overlaps the outer peripheral joint portion 13 of the first sheet 10 and is joined (diffusion bonding or brazing) to form a hollow portion between the first sheet 10 and the second sheet 20, A working fluid is enclosed therein to form a closed space 2 .
The width of the outer peripheral joint portion 23 indicated by R in FIGS. It is preferably the same as the width A of the outer peripheral joint portion 13 . However, they do not necessarily have to be the same, and may be larger or smaller.

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

The outer peripheral liquid channel portion 24 is a liquid channel portion, and is a portion that constitutes a part of the condensed liquid channel 3, which is the second channel through which the working fluid condenses and liquefies.

The outer peripheral liquid flow path portion 24 is formed along the inner side of the outer peripheral joint portion 23 on the inner surface 20 a of the main body 21 and along the outer periphery of the sealed space 2 . In this embodiment, the outer peripheral liquid channel portion 24 of the second sheet 20 is flush with the outer peripheral joint portion 23 as can be seen from FIGS. 19 and 20 . As a result, the openings of at least some of the liquid flow channels 14a of the plurality of liquid flow channels 14a of the first sheet 10 are closed to form the condensate flow channels 3, which are the second flow channels. A detailed aspect of the combination of the first sheet 10 and the second sheet 20 will be described later.
Since the outer peripheral joint portion 23 and the outer peripheral liquid flow path portion 24 are flush with each other in the second sheet 20 as described above, there is no boundary line that distinguishes them structurally. However, for the sake of clarity, the boundary between the two is represented by a dotted line in FIG.

It is preferable that the outer peripheral liquid flow path section 24 has the following configuration.
The width of the outer peripheral liquid flow path portion 24 indicated by S in FIGS. 18 to 20 (the width in the direction orthogonal to the direction in which the outer peripheral liquid flow path portion 24 extends and the width at the joint surface with the first sheet 10) is It is preferably different from the width B of the outer peripheral channel portion 14 of the first sheet 10 . That is, when the first sheet 10 and the second sheet 20 are combined, the vapor flow path 4, which is the first flow path, has a condensing flow path, which is the second flow path, in the thickness direction of the vapor chamber. A step is provided at the position where the liquid flow path is arranged.
As a result, even if the first sheet 10 and the second sheet 20 are slightly misaligned when they are joined together, the outer peripheral liquid flow path portion 14 and the outer peripheral liquid flow path portion 24 can be superimposed more easily. Therefore, accuracy control can be relaxed during production, and productivity, such as yield improvement, can be enhanced.
In addition, in the present embodiment, by making the width S smaller than the width B, as will be described later, the liquid flow channel grooves 14 a are part of the vapor flow channel 4 in at least a part of the outer peripheral liquid flow channel portion 14 . At this portion, the opening of the liquid channel groove 14a is not closed by the outer peripheral liquid channel portion 24, but is opened, and the condensate easily enters from here, so that the condensate can be returned more smoothly. can be done.
From this point of view, the size of the width S is preferably half or more of the width B of the peripheral liquid flow path portion 14 of the first sheet 10 shown in FIG. If the width S is smaller than half the width B, the number of the liquid channel grooves 14a that can close the openings is reduced, so there is a risk that the capillary force in the condensate channel 3 will be insufficient. On the other hand, the width S is preferably _B1 or less. Here, _B1 is a position that is half the width of the liquid flow channel 14a closest to the steam flow channel 16 among the liquid flow channels 14a arranged in the outer peripheral liquid flow channel 14, and It means the distance between the end portion of the portion 14 on the side of the outer peripheral joint portion 13 . From the viewpoint of this embodiment, if the width S is larger than _B1 , the opening of the liquid flow channel 14a exposed to the steam flow channel 4 is reduced, and the condensate flows into the liquid flow channel 14a less. There is fear.

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 that constitutes the condensate flow path 3 that is the second flow path.
As can be seen from FIGS. 17 to 20, the inner liquid flow path portion 25 is formed inside the ring of the outer peripheral liquid flow path portion 24 in the inner surface 20a of the main body 21. As shown in FIG. The inner liquid flow path part 25 of this embodiment is a wall extending in a direction (x direction) parallel to the long side of the main body 21 which is rectangular in plan view. They are arranged at predetermined intervals in a direction (y direction) parallel to the same short side.
In this embodiment, each inner liquid flow path portion 25 has a flat surface on the inner surface 20 a side before being joined to the first sheet 10 . As a result, the condensate flow path 3 is formed by closing the openings of at least some of the plurality of liquid flow grooves 15 a of the first sheet 10 .

The width of the inner liquid flow path portion 25 indicated by T in FIGS. width) is preferably different from the width G of the inner liquid flow path portion 15 of the first sheet 10 . According to this, when the first sheet 10 and the second sheet 20 are combined, the vapor channel 4 which is the first channel has the second channel in the thickness direction of the vapor chamber among the inner surfaces thereof. , there is a step at the position where the condensate flow path is arranged.
As a result, even if the first sheet 10 and the second sheet 20 are slightly misaligned when they are joined together, the inner liquid flow path section 15 and the inner liquid flow path section 25 can be easily overlapped. Therefore, accuracy control can be relaxed during production, and productivity, such as yield improvement, can be enhanced.
Further, in the present embodiment, the width T is made smaller than the width G, so that the liquid flow channel groove 15a is included in a part of the steam flow channel 4 in at least a part of the inner liquid flow channel portion 15, as will be described later. In other words, since the opening of the liquid channel groove 15a is not closed by the inner liquid channel portion 25 at this portion and the condensate easily enters from this portion, the condensate can be returned more smoothly.
From this point of view, in the present embodiment, the size of the width T is preferably G2 or _more in relation to the width G of the inner liquid flow path portion 15 of the first sheet 10 shown in FIG. As shown in _FIG . 14, G2 is the distance between the vapor flow groove 16 side ends of the second liquid flow groove 15a from the vapor flow groove 16 side among the plurality of liquid flow grooves 15a. is. If the width T is smaller _than G2, the number of the liquid flow channel grooves 15a that can close the opening is reduced, so that the capillary force in the condensate flow channel 3 may be insufficient.
On the other hand, from the viewpoint of this embodiment, the width T is preferably G1 or _less . As shown in FIG. 14, G1 is the distance between positions that are half the width of the _first liquid flow channel 15a from the vapor flow channel 16 side among the plurality of liquid flow channels 15a. . From the viewpoint of this embodiment, if the width T is larger _than G1, the opening of the liquid flow channel groove 15a exposed to the steam flow channel 4 is reduced, and there is a possibility that the condensate will flow into the liquid flow channel groove 15a less. be.

In this embodiment, each inner liquid flow path portion 25 is formed with a flat surface before joining, but liquid flow path grooves may be formed in the same manner as in the first sheet. In that case, the liquid flow channels may be located at the same position in a plan view, or they may be shifted from each other.

Next, the steam channel groove 26 will be explained. The steam flow channel groove 26 is a portion through which the vapor obtained by evaporating the working fluid passes, and constitutes a part of the steam flow channel 4 which is the first flow channel. FIG. 18 shows the shape of the steam flow channel groove 26 in plan view, and FIG. 19 shows the cross-sectional shape of the steam flow channel groove 26 .
As can be seen from these figures, the steam channel groove 26 is formed by a groove formed inside the annular ring of the outer peripheral liquid channel portion 24 in the inner surface 20 a of the main body 21 . Specifically, the steam flow channel grooves 26 of this embodiment are formed between the adjacent inner liquid flow channel portions 25 and between the outer peripheral liquid flow channel portion 24 and the inner liquid flow channel portion 25, and are It is a rectangular groove extending in a direction (x direction) parallel to the long side. A plurality of (four in this embodiment) steam flow channels 26 are arranged in a direction (y-direction) parallel to the same short side. Therefore, as can be seen from FIG. 19 , the second sheet 20 is formed in the y direction by the protrusions formed by the walls, which are the outer peripheral liquid flow path section 24 and the inner liquid flow path section 25 , and the recesses formed by the grooves, which are the vapor flow path grooves 26 . , and has a shape in which these irregularities are repeated.
Here, since the steam channel groove 26 is a groove, its cross-sectional shape has a bottom portion on the side of the outer surface 20b and an opening on the side of the inner surface 20a on the opposite side facing the bottom portion. .

The steam flow channel grooves 26 are preferably arranged at positions overlapping the steam flow channel grooves 16 of the first sheet 10 in the thickness direction when combined with the first sheet 10 . Thus, the steam channel groove 16 and the steam channel groove 26 can form the steam channel 4 which is the second channel.

The width of the steam channel groove 26 indicated by U in FIGS. It is preferably different from the width M of the steam channel grooves 16 of the sheet 10 . As a result, even if the first sheet 10 and the second sheet 20 are slightly misaligned when they are joined together, the inner liquid flow path portion 15 and the inner liquid flow path portion 25 can be easily overlapped. Therefore, accuracy control can be relaxed during production, and productivity, such as yield improvement, can be enhanced.
Among them, in the present embodiment, the width U is larger than the width M, so that at least a part of the inner liquid flow path portion 15 of the first sheet 10 has the liquid flow path grooves 15a that correspond to the vapor flow paths, as will be described later. 4, and the opening of the liquid channel groove 15a is exposed to the steam channel 4 at this portion, so that the condensate can easily enter, and the condensate can be circulated more smoothly.
On the other hand, the depth of the steam channel groove 26 indicated by V in FIG. 19 is preferably 300 μm or less, and may be 225 μm or less, or may be 150 μm or less. On the other hand, the depth V is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of depth V may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of depth V may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
Also, the depth of the steam channel groove 16 of the first sheet 10 and the steam channel groove 26 of the second sheet 20 may be the same, and may be larger or smaller.

In this embodiment, the cross-sectional shape of the steam flow channel groove 26 is rectangular, but it may be a square such as a square, a trapezoid, a triangle, a semi-circle, a semi-circular bottom, a semi-elliptical bottom, or a combination of some of these. may It can be made semi-circular following the example of FIG. This shape allows etching to be used to create vapor flow channels.
Since the steam flow path can smoothly circulate the working fluid by reducing the flow resistance of the steam, the shape of the cross section of the flow path can also be determined from this point of view.

In this embodiment, an example in which one vapor flow channel groove 26 is formed between adjacent inner liquid flow channel portions 25 has been described. A configuration in which the steam channel grooves are arranged side by side may also be used.
Further, as long as the first sheet 10 is formed with the steam channel grooves, the second sheet 20 may be partially or wholly not formed with the steam channel grooves.

The steam flow channel communication groove 27 is a groove that allows the plurality of steam flow channel grooves 26 to communicate with each other. As a result, the steam in the plurality of steam flow paths 4 can be equalized, and the steam can be transported over a wider range so that many condensate flow paths 3 can be efficiently used. It is possible to make the reflux of the more smooth.

As can be seen from FIGS. 18 and 20, the steam channel communication groove 27 of this embodiment is located between both ends in the extending direction of the inner liquid channel portion 25 and the steam channel groove 26 and the outer peripheral liquid channel portion 24. is formed in Further, FIG. 20 shows a cross section orthogonal to the communicating direction of the steam channel communicating groove 27 .

The width of the steam channel communication groove 27 indicated by W in FIGS. is preferably different from the width P of . Furthermore, the width W is made larger than the width P in this embodiment. More preferably, the degree of increase is greater than the width P within a range of 50 μm or more and 200 μm or less. Thereby, as will be described later in this embodiment, in at least a part of the outer peripheral liquid channel portion 14 of the first sheet 10, the openings of the liquid channel grooves 14a are arranged so as to form part of the vapor channel 4. As a result, the condensed liquid can easily enter, and the condensed liquid can be circulated more smoothly.

On the other hand, the depth of the steam channel communication groove 27 indicated by X in FIG. 20 is preferably 300 μm or less, and may be 225 μm or less, or may be 150 μm or less. On the other hand, the depth X is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of depth X may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, the range of depth X may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.
Also, the depth of the steam flow path communication groove 17 of the first sheet 10 and the steam flow path communication groove 27 of the second sheet 20 may be the same, and may be larger or smaller.

In this embodiment, the cross-sectional shape of the steam flow channel communication groove 27 is rectangular, but is not limited to this, and may be square, trapezoidal or other quadrangular, triangular, semi-circular, bottom semi-circular, semi-elliptical, or any of these. It may be a combined shape. It can be semi-circular, following the example of FIG. With this shape, it is possible to fabricate a vapor passage communication groove using etching.
Since the flow resistance of the steam in the steam channel can be reduced to allow smooth circulation of the steam, the cross-sectional shape of the channel can be determined from this point of view.

Next, the structure when the first sheet 10 and the second sheet 20 are combined to form the vapor chamber 1 will be described. With this explanation, the arrangement, size, shape, etc. of each configuration of the first sheet 10 and the second sheet 20 are further understood.
FIG. 21 shows a cross section obtained by cutting the vapor chamber 1 in the thickness direction along the y direction indicated by XVIII-XVIII in FIG. 5 of the first sheet 10 and FIG. 19 of the second sheet 20 are combined to show the cut surface of the vapor chamber 1 at this portion.
22 is an enlarged view of the portion indicated by XIX in FIG. 21, and FIG. 23 is a further enlarged view of the portion where the inner liquid channel portion 15 and the inner liquid channel portion 25 overlap in FIG. 24 shows a further enlarged view of the overlapping portion of the outer peripheral liquid channel portion 14 and the outer peripheral liquid channel portion 24 in FIG.
FIG. 25 shows a cross section cut in the thickness direction of the vapor chamber 1 along the x direction indicated by XXII-XXII in FIG. 7 of the first sheet 10 and FIG. 20 of the second sheet 20 are combined to show the cut surface of the vapor chamber 1 at this portion.

As can be seen from FIGS. 1, 2, and 21 to 25, the vapor chamber 1 is formed by arranging the first sheet 10 and the second sheet 20 so as to overlap and joining them. At this time, the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20 are arranged to face each other. The injection part 12 and the injection part 22 of the second sheet 20 overlap each other. In this 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 with the holes 23a of the second sheet 20. ing.

By such a laminate of the first sheet 10 and the second sheet 20, the main body 11 and each configuration provided in the main body 21 are arranged as shown in FIGS. 21 to 25. FIG. Specifically, it is as follows.

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

The peripheral liquid channel portion 14 of the first sheet 10 and the peripheral liquid channel portion 24 of the second sheet 20 are arranged so as to overlap each other. As a result, the condensate flow path 3, which is the second flow path through which the condensate in which the working fluid is condensed and liquefied by the liquid flow groove 14a of the outer peripheral liquid flow path portion 14 and the outer peripheral liquid flow path portion 24, is formed. be done. Since the condensate flow path 3 is formed separately from the steam flow path 4 which is the first flow path, it is possible to smoothly circulate the working fluid.

Here, as can be seen from FIGS. 21 to 25, in this embodiment, the width B of the outer peripheral liquid channel portion 14 of the first sheet 10 is greater than the width S of the outer peripheral liquid channel portion 24 of the second sheet 20. is also greatly formed. Therefore, the vapor channel 4, which is the first channel, has a step on the inner surface thereof at the position where the condensate channel, which is the second channel, is arranged in the thickness direction of the vapor chamber.
As a result, even if the first sheet 10 and the second sheet 20 are joined together, even if there is a slight misalignment, the joining accuracy can be moderated. Therefore, accuracy control can be relaxed during production, and productivity, such as yield improvement, can be enhanced.

Further, in this embodiment, among the plurality of liquid flow channel grooves 14 a provided in the outer peripheral liquid flow channel portion 14 , the liquid flow channel groove 14 a on the vapor flow channel 4 side is the outer peripheral liquid flow channel portion 24 of the second sheet 20 . do not overlap, the opening is not blocked. 22 to 25, an opening facing the second sheet 20 is formed at this portion, and the opening is included in a part of the steam flow path 4, so that the steam flows. Communicates with Road 4.
By disposing at least part of the condensate flow path in the vapor flow path in this way, the condensate can easily flow into the liquid flow path groove 14a, which is the condensate flow path 3, and the return of the working fluid can be improved. become smoother.
On the other hand, in the groove of the liquid channel groove 14a, the opening of which is closed by the outer peripheral liquid channel portion 24, the four sides of the cross section form walls, so the capillary force acts strongly, and the liquid flows smoothly. .

The inner liquid channel portion 15, which is the wall of the first sheet 10, and the inner liquid channel portion 25, which is the wall of the second sheet 20, are arranged so as to overlap each other. As a result, the condensate, which is the second flow path through which the condensate in which the working fluid is condensed and liquefied in the hollow portion by the liquid flow groove 15 a of the inner liquid flow path portion 15 and the inner liquid flow path portion 25 flows. A flow path 3 is formed.
Since the condensate flow path 3 is formed separately from the steam flow path 4, the working fluid can be smoothly circulated.
Furthermore, since the inner liquid flow path portion 15 and the inner liquid flow path portion 25 overlap each other, they function as support columns inside the closed space 2, so that defects such as collapse during manufacturing can be suppressed.

21 to 25, in this embodiment, the width G of the inner liquid flow path portion 15 of the first sheet 10 is larger than the width T of the inner liquid flow path portion 25 of the second sheet 20. formed large. Therefore, the vapor channel 4, which is the first channel, has a step on the inner surface thereof at the position where the condensate channel, which is the second channel, is arranged in the thickness direction of the vapor chamber.
As a result, even if the first sheet 10 and the second sheet 20 are joined together, even if there is a slight misalignment, the joining accuracy can be moderated. Therefore, accuracy control can be relaxed during production, and productivity, such as yield improvement, can be enhanced.
Furthermore, within this relaxed allowable range, the steam flow path 4 having the width of the narrower one of the steam flow path groove 16 and the steam flow path groove 26 (in this embodiment, the steam flow path groove 16) is secured. be able to. Therefore, from the viewpoint of the flow path resistance of the steam flow path 4, it is possible to widen the range in which the resistance can be kept constant, suppress the variation in the heat transport capacity of each product, and achieve the desired performance. can be stably supplied.

Further, in this embodiment, among the plurality of liquid flow channel grooves 15 a provided in the inner liquid flow channel portion 15 , the liquid flow channel groove 15 a on the vapor flow channel 4 side is the inner liquid flow channel portion 25 of the second sheet 20 . do not overlap, the opening is not blocked. 22 to 25, an opening facing the second sheet 20 is formed at the stepped portion of the steam channel 4 as shown by β in FIGS. , and communicates with the steam flow path 4 .
By disposing at least part of the condensate flow path in the vapor flow path in this way, the condensate can easily flow into the liquid flow path groove 15a, which is the condensate flow path, and the return of the working fluid can be made smoother. become.

On the other hand, in the groove of the liquid flow channel 15a, the opening of which is closed by the inner liquid flow channel portion 25, the four sides of the cross section form walls, so that the capillary force acts strongly and the liquid flows smoothly. .

From the viewpoint of exerting the capillary force of the channel more strongly in the condensed liquid channel 3 of each of the above examples, the aspect ratio (length and width) of the channel cross section represented by the value obtained by dividing the channel width by the channel height ratio) is preferably greater than 1.0. This ratio may be 1.5 or more, or 2.0 or more. Alternatively, the aspect ratio may be less than 1.0. This ratio may be 0.75 or less, or may be 0.5 or less.
Among these, from the viewpoint of manufacturing, the channel width is preferably larger than the channel height, and from this viewpoint, the aspect ratio is preferably larger than 1.3.

The opening of the steam channel groove 16 of the first sheet 10 and the opening of the steam channel groove 26 of the second sheet 20 are overlapped so as to face each other to form a channel, and this is the first channel through which the steam flows. Road 4.
The flow channel cross-sectional area of the condensate flow channel 3, which is the second flow channel, is made smaller than the flow channel cross-sectional area of the vapor flow channel 4, which is the first flow channel. More specifically, _Ag , and a plurality of condensate flow paths 3 arranged between two adjacent steam flow paths 4 (in this embodiment, formed by one inner liquid flow path portion 15 and one inner liquid flow path groove 25 When the average channel cross-sectional area of the plurality of condensate channels 3) is _A1 , the condensate channel 3 and the steam channel 4 have a relationship in which _A1 is 0.5 times or less _Ag . and preferably 0.25 times or less. This makes it easier for the working fluid to selectively pass through the first channel and the second channel depending on its phase mode (gas phase, liquid phase).
This relationship may be satisfied in at least a portion of the entire vapor chamber, and more preferably in the entire vapor chamber.

As can be seen from FIG. 25 , overlapping channels are formed so that the opening of the steam channel communication groove 17 of the first sheet 10 and the opening of the steam channel communication groove 27 of the second sheet 20 face each other.

On the other hand, as shown in FIGS. 1 and 2, the injection parts 12 and 22 are also overlapped so that the inner surface 10a and the inner surface 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 formed. An injection channel 5 is formed which is closed from the inner surface 10a of the injection portion 12 of the first sheet 10 and communicates the outside with the main body 11 and the hollow portion between the main bodies 21 (the condensate flow channel 3 and the vapor flow channel 4). ing.
However, after the working fluid is injected from the injection channel 5 into the hollow portion and sealed to form the sealed space 2, the injection channel 5 is closed, so the vapor chamber 1 in the final form is connected to the outside. It does not communicate with the closed space 2 .

In this embodiment, an example in which the injection part 12, the injection part 22, and the injection flow path 5 resulting therefrom are provided at one end of a pair of ends in the longitudinal direction of the vapor chamber 1 is shown. It is not limited to this, and may be arranged at any other end, or may be arranged in plurality. When a plurality of them are arranged, for example, they may be arranged at each of a pair of ends in the longitudinal direction of the vapor chamber 1, or may be arranged at one end of the other pair of ends.

A closed space 2 of the vapor chamber 1 is filled with working fluid. Although the type of working fluid is not particularly limited, working fluids used in ordinary vapor chambers, such as pure water, ethanol, methanol, acetone, and mixtures thereof, can be used.

The vapor chamber as described above can be manufactured, for example, as follows. Although the first sheet 10 will be described here, the second sheet 20 can also be manufactured in a similar manner.

First, a metal sheet having the outer peripheral shape of the first sheet 10 and having flat front and back surfaces is prepared.
Subsequently, this metal sheet is half-etched to form the steam channel grooves 16 forming part of the enclosed space 2 . More specifically, a resist film is laminated on the surface of the metal sheet to be half-etched, and a portion of the resist film is removed in the pattern of the vapor channel grooves by photolithography. Then, the portion from which the resist film has been removed is half-etched to form the vapor channel groove 16 . As a result, an inner liquid flow channel portion, an outer peripheral liquid flow channel portion, and an outer peripheral joint portion, which are not provided with liquid flow channel grooves, are formed in the portions where the vapor flow channel grooves are not formed.
The term "half-etching" as used herein means etching halfway in the thickness direction of the metal sheet without penetrating the metal sheet.

Next, the metal sheet is further half-etched to form a liquid flow channel 14a and a liquid flow channel 15a that constitute a part of the hollow portion that will become the closed space 2. As shown in FIG. In this case, a resist film is laminated on the surface of the metal sheet on which the vapor channel grooves 16 are formed, and a part of the resist film is removed in the pattern of the liquid channel grooves by a photolithographic technique. By half-etching the portion from which the resist film has been removed, the liquid flow channel grooves 14a and the liquid flow channel portions 15a are formed in the inner liquid flow channel portion and the outer peripheral liquid flow channel portion.

Next, the inner surfaces 10a and 20a of the first sheet 10 and the second sheet 20 produced as described above are stacked so as to face each other, positioned using the holes 13a and 23a as positioning means, and temporarily fixed. Temporary fixing methods are not particularly limited, but resistance welding, ultrasonic welding, bonding with an adhesive, and the like can be mentioned.
After temporary fixing, diffusion bonding is performed to permanently bond the first sheet 10 and the second sheet 20 together. Brazing may be used instead of diffusion bonding. Here, the term "permanently joined" is not limited to a strict meaning. It means that the second sheet 20 is joined to the extent that the inner surface 20a of the second sheet 20 can be joined.
In this embodiment, since the inner liquid flow path portion 15 and the inner liquid flow path portion 25 have the relationship as described above, the positioning accuracy can be moderately set, and productivity can be improved.

After joining, the formed injection channel 5 is evacuated to reduce the pressure in the hollow portion. After that, the working fluid is injected from the injection channel 5 into the decompressed hollow portion, and the working fluid is introduced into the hollow portion. Then, the sealed space 2 is formed by closing the injection channel 5 by melting the injection part 12 and the injection part 22 by laser or caulking. The working fluid is thereby retained inside the closed space 2 .

In the vapor chamber of this embodiment, the overlapping of the inner liquid flow path portion 15 and the inner liquid flow path portion 25 functions as a support, so that the closed space can be prevented from collapsing during bonding and depressurization.

Although manufacturing the vapor chamber by etching has been described above, the manufacturing method is not limited to this, and the vapor chamber can also be manufactured by pressing, cutting, laser processing, and processing using a 3D printer.
For example, when a vapor chamber is manufactured by a 3D printer, it is not necessary to manufacture the vapor chamber by bonding a plurality of sheets, and it is possible to create a vapor chamber without a bonded portion.

Next, the action of the vapor chamber 1 will be described. FIG. 26 schematically shows a state in which the vapor chamber 1 is arranged inside a portable terminal 40, which is one form of electronic equipment. Since the vapor chamber 1 is arranged inside the housing 41 of the portable terminal 40 here, it is represented by a dotted line. Such a portable terminal 40 includes a housing 41 containing various electronic components and a display unit 42 exposed through an opening of the housing 41 so that an image can be seen to the outside. As one of these electronic components, an electronic component 30 to be cooled by the vapor chamber 1 is arranged in the housing 41 .

The vapor chamber 1 is installed in a housing such as a form-type terminal, and is attached to an electronic component 30, such as a CPU, which is an object to be cooled. The electronic component 30 is attached directly to the outer surface 10b or the outer surface 20b of the vapor chamber 1, or via another member such as an adhesive, a sheet, or a tape having high thermal conductivity. At which position of the outer surface 10b or the outer surface 20b the object to be cooled is attached is not particularly limited, and is appropriately set according to the arrangement of other members in the mobile terminal or the like. In this embodiment, the electronic component 30, which is the heat source to be cooled, is arranged in the center of the main body 11 in the xy direction on the outer surface 10b of the first sheet 10, as indicated by the dotted line in FIG. Therefore, in FIG. 1, the electronic component 30 is indicated by a dotted line because it is a blind spot and cannot be seen.
FIG. 27 shows a diagram for explaining the flow of the working fluid. For ease of explanation, the second sheet 20 is omitted in this figure, and the inner surface 10a of the first sheet 10 is shown.

When the electronic component 30 generates heat, the heat is transferred through the first sheet 10 by heat conduction, and the condensate present in the closed space 2 near the electronic component 30 receives heat. The condensate that has received this heat absorbs the heat and evaporates. Electronic component 30 is thereby cooled.

The vaporized working fluid turns into vapor and moves through the vapor channel 4, which is the first channel, as indicated by solid line arrows in FIG. Since this flow occurs away from the electronic component 30 , the vapor moves away from the electronic component 30 .
The vapor in the vapor passage 4 leaves the electronic component 30 which is the heat source, moves to the outer peripheral portion of the vapor chamber 1 where the temperature is relatively low, and sequentially transfers heat to the first sheet 10 and the second sheet 20 during the movement. It is cooled while being taken away. The first sheet 10 and the second sheet 20 that have taken heat from the steam transfer heat to the housing 41 of the portable terminal 40 that is in contact with the outer surface 10b and the outer surface 20b, and the heat is finally released to the outside air.

The working fluid that has lost heat while moving through the steam flow path 4 condenses and liquefies. This condensate adheres to the walls of the steam flow path 4 . On the other hand, since the steam is continuously flowing through the steam passage 4, the condensate is pushed by the steam as indicated by the arrow Z2 in FIGS. Move to Road 3. As shown in FIGS. 8 and 15, the condensate flow path 3 of this embodiment has a communication opening 14c and a communication opening 15c. distributed through a plurality of condensate channels 3 .
In this embodiment, since the condensate flow path 3 and the vapor flow path 4 are configured separately, the working fluid smoothly flows back.

Furthermore, in the vapor chamber 1 of the present embodiment, a part of the condensate flow path 3 is provided in the vapor flow path 4 at the step portion provided in the vapor flow path 4, so that the condensate flows in FIGS. It moves into the condensate flow path ₃ so as to be pushed by the steam also from the thickness direction as indicated by the arrow Z3 at 25 . Therefore, the condensate can easily enter the condensate flow path 3, and the working fluid can be smoothly circulated.

The condensate that has entered the condensate flow path 3 moves toward the electronic component 30, which is the heat source, as indicated by the dotted straight arrow in FIG. Moving.
In particular, in a part of the condensate flow channel 3 that is not arranged in the steam flow channel 4, the openings of the liquid flow channel grooves 14a and 15a are blocked by the second sheet 20. Its four sides become walls, and the capillary force can be enhanced. This allows the condensate to move more smoothly.
Then, it is vaporized again by the heat from the electronic component 30 which is the heat source, and the above process is repeated.

As described above, according to the vapor chamber 1, the condensate flows smoothly into the condensate flow path 3, which is the second flow path. be able to. In addition, since the vapor flow path is structured such that condensate is less likely to accumulate, the heat transport capacity can be enhanced from this point of view as well.

In the above-described embodiment, in the steps provided in the steam channel 4, the liquid channel grooves are included in a part of the steam channel without closing the openings of some of the liquid channel channels. However, without being limited to this, the condensate flow path may be provided such that the openings of all the liquid flow grooves are closed and the cross section of the flow path is surrounded on all four sides by walls. A specific shape is shown in FIG.
In this example, as in the above embodiment, the outer peripheral liquid channel portion 14 of the first sheet 10 is wider than the outer peripheral liquid channel portion 24 of the second sheet 20, and the inner liquid channel portion 15 of the first sheet 10 is Since the width is wider than the inner liquid channel portion 25 of the second sheet 20, the vapor channel 4, which is the first channel, has the condensate liquid, which is the second channel, in the thickness direction of the vapor chamber. There is a step at the position where the flow path is arranged.
However, in this embodiment, the openings on the inner surface 10a side of all the liquid flow channel grooves 14a are blocked by the outer peripheral liquid flow channel portion 24 or the inner liquid flow channel portion 25. FIG.
In such a configuration, the condensate is likely to move to the stepped portion provided in the steam flow path 4 as indicated by Z4 in FIG. through to the condensate channel 3, which is the second channel. Therefore, even in this configuration, the condensate moves smoothly from the vapor channel to the condensate channel, and stable heat transport capability can be exhibited.

In each of the above-described forms, the width of the outer peripheral liquid channel portion 14 and the inner liquid channel portion 15 of the first sheet 10 is
An example in which the width is larger than the width of the liquid flow path portion 24 and the inner liquid flow path portion 25 of the second sheet 20 has been described. The configuration is not limited to this, and the relationship may be reversed. FIG. 29 shows a diagram for explanation.

In the vapor chamber 1 of this embodiment, the relationship between the width of the outer peripheral liquid flow path portion 14 of the first sheet 10 and the width of the outer peripheral liquid flow path portion 24 of the second sheet 20 is the above-described vapor chamber 1. is the opposite. Similarly, the relationship between the width of the inner liquid flow path portion 15 of the first sheet 10 and the width of the inner liquid flow path portion 25 of the second sheet 20 is opposite to that of the vapor chamber 1 having the above-described configuration. .

That is, the width of the outer peripheral liquid channel portion 14 of the first sheet 10 is smaller than the width of the outer peripheral liquid channel portion 24 of the second sheet 20, and the width of the inner liquid channel portion 15 of the first sheet 10 is smaller than the width of the outer peripheral liquid channel portion 24 of the second sheet 20. is smaller than the width of the inner liquid flow path portion 25 of the second sheet 20 . Therefore, when the first sheet 10 and the second sheet 20 are combined, the vapor flow path 4, which is the first flow path, has a condensate flow path, which is the second flow path, in the thickness direction of the vapor chamber. A step is provided at the position where the liquid flow path is arranged.
As a result, the steam flow path and the condensate flow path are separated, and the working fluid can be circulated more smoothly. In addition, the positioning accuracy can be moderately set when the first sheet 10 and the second sheet 20 are joined, and productivity can be improved. Since the inner liquid flow path portion 15 and the inner liquid flow path portion 25 overlap and function as a support, it is possible to suppress the collapse of the closed space during bonding and depressurization.
In addition, as indicated by Z5 in FIG. 29, the condensed liquid is likely to move to the stepped portion provided in the steam flow path 4, and this condensed liquid passes through the communicating openings 14c and 15c from here to the second Since the condensate moves to the condensate flow path 3, which is a flow path, the condensate moves smoothly from the vapor flow path to the condensate flow path even in this form, and stable heat transport performance can be exhibited.

Although the above embodiment is an example in which the liquid flow channel is provided only in the first sheet, the liquid flow channel may be provided in the second sheet as well. 30 and 31 show diagrams for explanation. In both FIGS. 30 and 31, the second sheet 20 is provided with the liquid channel grooves 24a and the liquid channel grooves 25a. The liquid flow channel 24a and the liquid flow channel 25a overlap with the liquid flow channel 14a and the liquid flow channel 15a of the first sheet 10 to form the condensate liquid flow channel 3 as the second flow channel.
The example of FIG. 30 is an example in which the liquid flow channel 14a and the liquid flow channel 24, and the liquid flow channel 15a and the liquid flow channel 25 are arranged at the same position in the width direction (y direction). is.
The example of FIG. 31 is an example in which the liquid flow channel 14a and the liquid flow channel 24, and the liquid flow channel 15a and the liquid flow channel 25 are arranged so as to be shifted at different positions in the width direction (y direction). is.
Since the capillary force in the condensate flow path can be exerted in any arrangement, the above-described effects can be obtained.
30 and 31, the groove width, depth, and cross-sectional shape of the liquid flow grooves 14a and 24, and the groove width, depth, and cross-sectional shape of the liquid flow grooves 15a and 25 are the same. However, at least one of them may be different.

Up to this point, the vapor chamber 1 has been described as an example composed of two sheets, the first sheet 10 and the second sheet. However, it is not limited to this, and a vapor chamber with three or more sheets as shown in FIGS. 32 and 33 may be used. FIG. 32 is an example of a vapor chamber consisting of three sheets, and FIG. 33 is an example of a vapor chamber consisting of four sheets.

The vapor chamber 1 shown in FIG. 32 is a laminate of a first sheet 10, a second sheet 20 and a third sheet (intermediate sheet) 50. As shown in FIG.
The third sheet 50 is arranged so as to be sandwiched between the first sheet 10 and the second sheet 20, the inner surface 10a of the first sheet 10 contacts one surface 50a of the third sheet 50, and the second sheet 20 The inner surface 20a of the third sheet 50 is in contact with the other surface 50b of the third sheet 50 and joined to each other. The mode of bonding is as described above.

Here, the first sheet 10 has a flat inner surface 10a, a liquid flow path portion 14a, and a liquid flow path portion 24a. The liquid channel portion 15 and the inner liquid channel portion 25 are not provided.
Similarly, the second sheet 20 has both an inner surface 20a and an outer surface 20b that are flat.
At this time, the thickness of the first sheet 10 and the second sheet 20 is preferably 1.0 mm or less, may be 0.5 mm or less, or may be 0.1 mm or less. On the other hand, the thickness is preferably 0.005 mm or more, may be 0.015 mm or more, or may be 0.030 mm or more. The thickness range may be defined by a combination of any one of the plurality of upper limit candidate values and one of the plurality of lower limit candidate values. Also, this thickness range may be determined by combining any two of a plurality of upper limit candidate values or by combining any two of a plurality of lower limit candidate values.

The third sheet 50 is provided with walls 51 and steam channels 52 .
The wall 51 is a wall arranged so as to bridge the first sheet 10 and the second sheet 20, and the outer peripheral liquid flow path portion 15 of the first sheet 10 and the outer peripheral liquid flow path portion 24 of the second sheet 20 described above. and the position where the inner liquid flow path portion 25 of the first sheet 10 and the inner liquid flow path portion 25 of the second sheet 20 are superimposed.
The steam flow channel groove 52 is a groove that penetrates the third sheet 50 in the thickness direction, and is located at a position where the steam flow channel groove 16 of the first sheet 10 and the steam flow channel groove 26 of the second sheet 20 are overlapped. placed in the same position as

Then, as can be seen from FIG. 32, the liquid flow path part 14a and the liquid flow path part 15a of the first sheet 10 are arranged so as to be covered with the surface 50a of the wall 51 of the third sheet 50, which is the second flow path. A condensate flow path 3 is formed. At this time, the width of the wall 51 and the width of the portion where the liquid flow paths 14a and 15a are arranged are configured to satisfy the relationship described above.
On the other hand, the flow path surrounded by the wall 51, the first sheet 10 and the second sheet 20 adjacent to each other becomes the steam flow path 4, which is the first flow path.

The vapor chamber 1 shown in FIG. 33 consists of four sheets and has a first sheet 10, a second sheet 20, a third sheet 60 and a fourth sheet . The first sheet 10, the third sheet 60, the fourth sheet 70, and the second sheet 20 are laminated in this order and joined. The mode of bonding is as described above.

The vapor chamber 1 shown in FIG. 33 is of a form in which the sheet is divided into four so as to have the same form as the vapor chamber 1 shown in FIG. That is, in this embodiment, the third sheet 60 has the outer peripheral liquid channel portion 14, the inner liquid channel portion 15, and the vapor channel groove 16, and the first sheet 10 does not have these. Similarly, the fourth sheet 70 has the outer liquid channel portion 24, the inner liquid channel portion 25, and the vapor channel groove 26, and the second sheet 20 does not have them.
Such a form can also be used as the vapor chamber of the present disclosure.

The above examples of the respective forms of the present disclosure are not limited as they are, and can be embodied by modifying the constituent elements without departing from the gist thereof. Further, various forms can be made by appropriately combining the plurality of constituent elements disclosed in the above forms and modifications. Some components may be deleted from all the components shown in each form and modification.

Reference Signs List 1 vapor chamber 2 closed space 3 condensate flow path 4 vapor flow path 10 first sheet 10a inner surface 10b outer surface 10c side surface 11 main body 12 injection section 13 outer peripheral joint 14 outer peripheral liquid flow path 14a liquid flow groove 14c communication opening 15 Inner liquid channel part 15a Liquid channel groove 15c Communication opening 16 Steam channel groove 17 Steam channel communication groove 20 Second sheet 20a Inner surface 20b Outer surface 20c Side surface 21 Main body 22 Injection part 23 Outer peripheral joint part 24 Outer peripheral liquid channel part 25 inner liquid flow path part 26 vapor flow path groove 27 vapor flow path communication groove 30 electronic component 40 portable terminal (electronic device)
41 housing

Claims (1)

A vapor chamber having a closed space in which a working fluid is enclosed,
In the closed space,
Having a plurality of first flow paths and a second flow path provided between the adjacent first flow paths,
_Let Ag be the average cross-sectional area of the two adjacent first channels, and A be the average cross-sectional area of the plurality of second channels arranged between the adjacent first channels. ₁ is at least _{partly 0.5 times or less than A g ,} and
The vapor chamber, wherein the first flow path has a step at a position where the second flow path is arranged in the thickness direction of the vapor chamber on the inner surface thereof.

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