Sheet with multi-layout of intermediate for vapor chamber, roll around which sheet with multi-layout of intermediate for vapor chamber is wound, intermediate for vapor chamber, and method for manufacturing vapor chamber

Abstract

To provide an intermediate in which an oxide film is less likely to be generated at an inner surface of a flow channel through which a working fluid flows, and to provide a sheet with multi-layout of an intermediate, a roll around which an intermediate is wound, and a method for manufacturing a vapor chamber.SOLUTION: An intermediate 352 for a vapor chamber is provided with a hollow part to work as a flow channel for a working fluid inside the intermediate. The hollow part is not injected with any working fluid. The hollow part is blocked from the outside.SELECTED DRAWING: Figure 77

Description

[Technical field]

[0001] The present disclosure relates to a vapor chamber that transports heat by circulating a working fluid sealed in a sealed space while undergoing a phase change. [Background technology]

[0002] The amount of heat generated by electronic components such as CPUs (Central Processing Units) in personal computers and mobile devices such as mobile phones and tablet computers tends to increase due to improvements in information processing capabilities, making cooling technology important. Heat pipes are a well-known means of cooling. These use a working fluid sealed inside the pipe to transport and diffuse heat from a heat source to other parts, thereby cooling the heat source.

[0003] On the other hand, in recent years, there has been a remarkable trend towards thinner devices, particularly in portable terminals, and a need has arisen for thinner cooling means than conventional heat pipes. In response to this, vapor chambers have been proposed, for example, as described in Patent Documents 1 to 3.

[0004] A vapor chamber is a device that applies the concept of heat transport by a heat pipe to a flat plate-shaped component. In other words, in a vapor chamber, a working fluid is sealed between opposing flat plates, and heat is transported by the working fluid circulating while undergoing a phase change, transporting and diffusing heat in a heat source to cool the heat source.

[0005] More specifically, a flow path through which the working fluid flows is provided between the opposing flat plates of the vapor chamber, and the working fluid is sealed in this path. When the vapor chamber is placed near the heat source, the working fluid receives heat from the heat source and evaporates, becoming a gas (vapor) and moving through the flow path. This allows the heat from the heat source to be smoothly transported to a position away from the heat source, resulting in the heat source being cooled. The working fluid in a gaseous state that transported the heat from the heat source moves to a position away from the heat source, where it is cooled and condensed as heat is absorbed by the surroundings, and changes phase to a liquid state. The working fluid in a liquid state that has changed phase passes through another flow path, returns to the position of the heat source, receives heat from the heat source again, and evaporates and changes to a gaseous state. By circulating as described above, the heat generated from the heat source is transported to a location away from the heat source, and the heat source is cooled. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5788069 [Patent Document 2] JP 2016-205693 A [Patent Document 3] Patent No. 6057952 Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure provides an intermediate body that is less likely to produce an oxide film on the inner surface of a flow path through which a working fluid flows, a sheet with the intermediate body attached on multiple sides, a roll around the intermediate body, and a method for manufacturing a vapor chamber. [Means for solving the problem]

[0008] The present application discloses an intermediate for a vapor chamber, the intermediate having a hollow portion therein to serve as a flow path for a working fluid, no working fluid being injected into the hollow portion, and the hollow portion being isolated from the outside.

[0009] Also disclosed is a sheet having the above intermediate body laminated thereon, and a roll having the sheet wound thereon.

[0010] Also disclosed is a method for manufacturing a vapor chamber from an intermediate, the intermediate having a hollow portion therein to serve as a flow path for the working fluid, no working fluid being injected into the hollow portion and the hollow portion being blocked off from the outside, the method including the steps of: manufacturing a sheet with multiple intermediates attached; removing individual intermediates from the sheet to manufacture intermediates; forming an injection port for injecting the working fluid into the hollow portion; an injection step of injecting the working fluid from the injection port; and a sealing step of closing the injection port when the working fluid has been injected. Effect of the Invention

[0011] According to the present disclosure, an intermediate body can be obtained in which an oxide film is unlikely to form on the inner surface of a flow passage through which a working fluid flows. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of the vapor chamber 1. [Diagram 2] FIG. 2 is an exploded perspective view of the vapor chamber 1. FIG. [Diagram 3] FIG. 3 is a perspective view of the first sheet 10. As shown in FIG. [Figure 4] FIG. 4 is a plan view of the first sheet 10. As shown in FIG. [Diagram 5] FIG. 5 is a cross section of the first sheet 10. [Figure 6] FIG. 6 is another cross-section of the first sheet 10. [Figure 7] FIG. 7 is another cross-section of the first sheet 10. [Figure 8] FIG. 8 is a partially enlarged plan view of the outer peripheral liquid flow path section 14. As shown in FIG. [Figure 9] FIG. 9 is a partially enlarged plan view of the outer peripheral liquid flow path section 14 according to another embodiment. [Figure 10]FIG. 10 is a partially enlarged plan view of the outer peripheral liquid flow path portion 14 according to another embodiment. [Figure 11] FIG. 11 is a partially enlarged plan view of the outer peripheral liquid flow path section 14 according to another embodiment. [Figure 12] FIG. 12 is a partially enlarged plan view of another example of the outer peripheral liquid flow path section 14. In FIG. [Figure 13] FIG. 13 is a cross section focusing on the inner liquid flow path portion 15. [Figure 14] FIG. 14 is a partially enlarged plan view of the inner liquid flow path section 15. As shown in FIG. [Figure 15] FIG. 15 is a perspective view of the second sheet 20. As shown in FIG. [Figure 16] FIG. 16 is a plan view of the second sheet 20. As shown in FIG. [Figure 17] FIG. 17 is a cross section of the second sheet 20. [Figure 18] FIG. 18 is a cross section of the second sheet 20. [Figure 19] FIG. 19 is a cross-section of the vapor chamber 1. [Figure 20] FIG. 20 is an enlarged view of a portion of FIG. [Figure 21] FIG. 21 is another cross-sectional view of the vapor chamber 1. [Figure 22A] FIG. 22A is a diagram illustrating the manufacture of the vapor chamber 1. [Figure 22B] FIG. 22B is a diagram illustrating the manufacture of the vapor chamber 1. [Figure 22C] FIG. 22C is a diagram illustrating the manufacture of the vapor chamber 1. [Figure 22D] FIG. 22D is a diagram illustrating the manufacture of the vapor chamber 1. [Figure 23] FIG. 23 is a diagram illustrating an electronic device 40. As shown in FIG. [Figure 24] FIG. 24 is a diagram illustrating the flow of the working fluid. [Diagram 25] FIG. 25 is a diagram illustrating a vapor chamber according to a modified example. [Figure 26] FIG. 26 is a diagram illustrating a vapor chamber according to a modified example. [Figure 27] FIG. 27 is a perspective view of the vapor chamber 101. [Figure 28] FIG. 28 is an exploded perspective view of the vapor chamber 101. [Figure 29] FIG. 29 is a perspective view of the first sheet 110. As shown in FIG. [Diagram 30] FIG. 30 is a plan view of the first sheet 110. [Diagram 31] FIG. 31 is a cross section of the first sheet 110. [Diagram 32] FIG. 32 is another cross-section of the first sheet 110. [Diagram 33] FIG. 33 is another cross-section of the first sheet 110. [Diagram 34] FIG. 34 is a partially enlarged plan view of the outer circumferential liquid flow path section 114. As shown in FIG. [Diagram 35] FIG. 35 is a cross section focusing on the inner liquid flow path portion 115. [Diagram 36] FIG. 36 is a partially enlarged plan view of the inner liquid flow path section 115. As shown in FIG. [Figure 37] FIG. 37 is a diagram for explaining an example of the shape of the curved portion 118c. [Figure 38] FIG. 38 is a diagram for explaining an example of the shape of the curved portion 118c. [Figure 39] FIG. 39 is a diagram for explaining an example of the shape of the curved portion 118c. [Diagram 40] FIG. 40 is a diagram for explaining an example of the shape of the curved portion 118c. [Diagram 41] FIG. 41 is a perspective view of the second sheet 120. As shown in FIG. [Diagram 42] FIG. 42 is a plan view of the second sheet 120. [Diagram 43] FIG. 43 is a cross section of the second sheet 120. [Diagram 44] FIG. 44 is another cross-section of the second sheet 120. [Diagram 45] FIG. 45 is a cross-section of the vapor chamber 101. [Diagram 46] FIG. 46 is an enlarged view of a portion of FIG. [Figure 47] FIG. 47 is another cross-sectional view of the vapor chamber 101. [Figure 48] FIG. 48 is a diagram for explaining an example of the configuration of the condensate flow path. [Figure 49] FIG. 49 is a diagram for explaining examples of the configuration of the condensate flow path. [Figure 50] FIG. 50 is a diagram for explaining an example of the configuration of the condensate flow path. [Figure 51] FIG. 51 is a diagram for explaining the condensate flow path 103 and the steam flow path 104. [Figure 52] FIG. 52 is a diagram for explaining the operation of the vapor chamber 101. [Diagram 53] FIG. 53 is a perspective view of the exterior of the vapor chamber 201. [Figure 54] FIG. 54 is an exploded perspective view of the vapor chamber 201. [Figure 55] FIG. 55 is a view of the third sheet 230 as seen from one side. [Figure 56] FIG. 56 is a view of the third sheet 230 as seen from the other surface side. [Figure 57] FIG. 57 is a cross section of the third sheet 230. [Figure 58] FIG. 58 is another cross-section of the third sheet 230. [Figure 59] FIG. 59 is a cross section of the vapor chamber 201. [Figure 60] FIG. 60 is an enlarged view of a portion of FIG. [Figure 61] FIG. 61 is another cross-section of the vapor chamber 201. [Figure 62] FIG. 62 is a diagram showing the flow of the manufacturing method S301 of the vapor chamber. [Figure 63] FIG. 63 is a diagram showing the flow of step S310. [Figure 64] FIG. 64 is a perspective view of the multi-imposed first sheet 301. FIG. [Figure 65] FIG. 65 is a perspective view showing one of the shapes 310 formed on the multi-imposed first sheet 301. As shown in FIG. [Figure 66]FIG. 66 is a plan view showing one of the shapes 310 formed on the multi-imposed first sheet 301. As shown in FIG. [Figure 67] FIG. 67 is a cross-sectional view showing one of the shapes 310 formed on the multi-imposed first sheet 301. As shown in FIG. [Figure 68] FIG. 68 is an enlarged view of a portion of FIG. [Figure 69] FIG. 69 is another cross-sectional view showing one of the shapes 310 formed on the multiple-imposed first sheet 301. As shown in FIG. [Figure 70] FIG. 70 is a partially enlarged plan view of the outer circumferential liquid flow path section 314. As shown in FIG. [Figure 71] FIG. 71 is a cross section focusing on one inner liquid flow path portion 315. [Figure 72] FIG. 72 is a partially enlarged plan view of the inner liquid flow path section 315. As shown in FIG. [Figure 73] FIG. 73 is a diagram for explaining bonding. [Figure 74] FIG. 74 is a diagram illustrating a sheet 350 on which an intermediate body is multi-faced, and a roll 351 on which the sheet on which an intermediate body is multi-faced is wound. [Figure 75] FIG. 75 is a partial cross-section of a sheet 350 to which an intermediate body is multi-faceted. [Figure 76] FIG. 76 is a perspective view of the intermediate body 352. FIG. [Figure 77] FIG. 77 is a plan view of the intermediate body 352. [Figure 78] FIG. 78 is a diagram illustrating the formation of the injection port 319. [Figure 79] FIG. 79 is a diagram illustrating the formation of the injection port 319. As shown in FIG. [Figure 80] FIG. 80 is a diagram for explaining the formation of another injection port 319. In FIG. [Figure 81] FIG. 81 is a diagram for explaining the formation of another injection port 319. In FIG. [Figure 82] FIG. 82 is a perspective view of the vapor chamber 353. [Figure 83] FIG. 83 is a plan view of the vapor chamber 353. [Figure 84] FIG. 84 is a cross-sectional view of the vapor chamber 353. [Figure 85] FIG. 85 is a diagram illustrating a vapor chamber 353 according to another embodiment. [Figure 86] FIG. 86 is a diagram illustrating a vapor chamber 353 according to another embodiment. [Figure 87] FIG. 87 is a diagram illustrating a vapor chamber 353 according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described below based on the embodiments shown in the drawings. In the drawings shown below, the size and ratio of components may be changed or exaggerated for ease of understanding. In addition, for ease of viewing, illustration of parts not necessary for explanation and repeated reference numerals may be omitted.

[0014] [First form] Fig. 1 shows an external perspective view of the vapor chamber 1 according to the first embodiment, and Fig. 2 shows an exploded perspective view of the vapor chamber 1. In these figures and each of the following figures, arrows (x, y, z) indicating directions are also shown for convenience as necessary. The xy in-plane direction is the plate surface direction of the flat vapor chamber 1, and the z direction is the thickness direction.

[0015] 1 and 2, the vapor chamber 1 has a first sheet 10 and a second sheet 20. As will be described later, the first sheet 10 and the second sheet 20 are stacked and joined (by diffusion bonding, brazing, etc.) to form a hollow space between the first sheet 10 and the second sheet 20, and a working fluid is sealed in the hollow space to form a sealed space 2 (see, for example, FIG. 19).

[0016] In this embodiment, the first sheet 10 is a sheet-like member as a whole. Fig. 3 shows a perspective view of the first sheet 10 seen from the inner surface 10a side, and Fig. 4 shows a plan view of the first sheet 10 seen from the inner surface 10a side. Fig. 5 shows a cross section of the first sheet 10 taken along the line I1-I1 in Fig. 4. 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 a pattern for a flow path for returning the working fluid is formed on the inner surface 10a side. As 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, and the working fluid is sealed in this to form the sealed space 2.

[0017] 5, in this embodiment, the first sheet 10 is configured to have an inner layer 10d made of a material that forms the inner surface 10a, and an outer layer 10e made of a material that forms the outer surface 10b. That is, the first sheet 10 is configured by laminating a plurality of layers, one of which forms the inner surface 10a and the other layers form the outer surface 10b. In this embodiment, the side surface 10c is formed by an end surface of the inner layer 10d and an end surface of the outer layer 10e.

[0018] Here, the inner surface 10a side of the first sheet 10 is provided with a pattern for the movement of the working fluid as described above, and the inner layer 10d constitutes the surface of this pattern that comes into direct contact with the working fluid. For this reason, the inner layer 10d is preferably made of a material that is chemically stable with respect to the working fluid and has high thermal conductivity. More specifically, for example, copper and copper alloys can be used. In particular, by using copper and copper alloys, it is possible to improve the heat transport capacity while suppressing reactions with the working fluid (particularly water), and further, it becomes easier to fabricate a vapor chamber as described later.

[0019] The outer layer 10e is laminated on the inner surface 10a side of the inner layer 10d, and forms the outer surface 10b. The outer layer 10e has a pattern formed on the inner surface 10a of the first sheet 10 on the side in contact with the inner layer 10d. However, as described above, the patterned portion of the outer layer 10e forms a flow path, but is covered by the inner layer 10d and is prevented from coming into direct contact with the working fluid. That is, the outer layer 10e has grooves that serve as flow paths (condensate flow paths and steam flow paths) for the working fluid, and the inner layer 10d is laminated inside the grooves.

[0020] On the other hand, in this embodiment, the surface of the outer layer 10e that will become the outer surface 10b is a flat surface or a slightly uneven surface, taking into consideration contact with parts placed in the vapor chamber 1. Therefore, in this embodiment, the outer layer 10e is configured so that the distance (ie, thickness) between the surface of the outer layer 10e that is in contact with the inner layer 10d on the inner surface 10a side and the outer surface 10b varies depending on the position in the x direction and the position in the y direction. This allows the vapor chamber to maintain its strength even if it is thinned while still forming a flow path.

[0021] Therefore, it is preferable that the outer layer 10e is made of a material having a higher strength than the inner layer 10d. Specifically, it is preferable that the 0.2% yield strength or upper yield point of the outer layer 10e is greater than the 0.2% yield strength or upper yield point of the inner layer 10d. There are no particular limitations as long as this is satisfied, but in order to achieve higher strength, it is preferable that the 0.2% yield strength or upper yield point of the outer layer 10e is 100 MPa or more, and more preferably 200 MPa or more. This allows the vapor chamber to have the desired flow path, and even when made thin, it is possible to prevent deformation or damage to the vapor chamber due to forces such as external impacts, expansion due to solidification of the working fluid through low-temperature freezing, and vapor pressure during operation. Furthermore, since the outer layer 10e can improve the strength of the vapor chamber in this manner, the strength constraints on the pattern of the flow path through which the working fluid moves, formed on the inner surface 10a, can be relaxed, making it possible to design with a focus on improving thermal performance, which can be said to be advantageous from the standpoint of thermal performance as well.

[0022] The material constituting the outer layer 10e is not particularly limited, but from the viewpoint of heat diffusion, it is preferable that the thermal conductivity is high, and preferably 10 W / m·K or more. From this viewpoint, examples of the material constituting the outer layer 10e include iron-based materials such as stainless steel, invar, and kovar, titanium alloys, and nickel alloys. Composite materials containing these metals and fine particles such as diamond, alumina, and silicon carbide may also be used.

[0023] The thickness of the inner layer 10d is not particularly limited in consideration of the specifications, but is preferably 5 μm to 20 μm. If the inner layer 10d is thinner than 5 μm, the possibility that the material of the outer layer 10e and the working fluid may affect each other increases. On the other hand, if the inner layer 10d is thicker than 20 μm, there is a high possibility that difficulties will arise from the viewpoint of manufacturing, that it will be difficult to meet the required thickness specifications including in-plane variations, and that the surface will become rough.

[0024] On the other hand, the thickness of the outer layer 10e is not particularly limited since it depends on the specifications, but it is preferable that the thickness is 0.02 mm or more and 0.5 mm or less at any part. If the outer layer 10e has a part thinner than 0.02 mm, the effect of suppressing deformation may be reduced, and if the outer layer 10e has a part thicker than 0.5 mm, the heat transfer from the vapor chamber to the outside may be hindered or it may be difficult to meet the thickness specifications.

[0025] The thickness of the first sheet 10 is the sum of the inner layer 10d and the outer layer 10e, but the specific thickness is not particularly limited. However, it is preferably 1.0 mm or less, and may be 0.75 mm or less, or may be 0.5 mm or less. On the other hand, this thickness is preferably 0.02 mm or more, and may be 0.05 mm or more, or may be 0.1 mm or more. This thickness range may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. In addition, this thickness range may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. This increases the number of situations in which it can be used as a thin vapor chamber. Even when the vapor chamber is thinned while having the desired flow path, it is possible to suppress deformation or damage to the vapor chamber due to external impacts, expansion caused by solidification of the working fluid by low-temperature freezing, and forces caused by vapor pressure during operation.

[0026] Such a first sheet 10 includes a main body 11 and an injection part 12. The main body 11 is in the form of a sheet that forms a part where the working fluid returns, and in this embodiment, is a rectangle with arc-shaped (so-called R) corners in a plan view. As described above, the inner surface 10a of the main body 11 and the injection part 12 is composed of the inner layer 10d, and the outer surface 10b is composed of the outer layer 10e.

[0027] The injection section 12 is a section where the working fluid is injected into the hollow section formed by the first sheet 10 and the second sheet 20. In this embodiment, it is a sheet-like shape that is quadrangular in plan view and protrudes from one side of the main body 11 that is rectangular in plan view. In this embodiment, both the inner surface 10a side and the outer surface 10b side of the injection section 12 of the first sheet 10 are flat surfaces.

[0028] A structure for the working fluid to circulate is formed on the inner surface 10a side of the main body 11. The main body 11 may be rectangular as in this embodiment, or may be circular, elliptical, triangular, or other polygonal, or may have a shape having a bent portion, such as an L-shape, a T-shape, or a crank shape. It may also be a shape that combines at least two of these shapes. The main body 11 is provided with an outer periphery joining portion 13, an outer periphery liquid flow passage portion 14, an inner liquid flow passage portion 15, a steam flow passage groove 16, and a steam flow passage communication groove 17 on the inner surface 10a side.

[0029] The outer periphery bonding portion 13 is a surface formed on the inner surface 10a side of the main body 11 along the outer periphery of the main body 11. This outer periphery bonding portion 13 is overlapped and bonded (by diffusion bonding, brazing, etc.) to the outer periphery bonding portion 23 of the second sheet 20, thereby forming a hollow portion between the first sheet 10 and the second sheet 20, and a working fluid is sealed in this hollow portion to form the sealed space 2. The width of the outer peripheral joint 13 indicated by W1 in FIG. 4 and FIG. 5 (the size in the direction perpendicular to the direction in which the outer peripheral joint 13 extends, and the width at the joint surface with the second sheet 20) can be set appropriately as necessary, but this width W1 is preferably 3.0 mm or less, may be 2.5 mm or less, or may be 2.0 mm or less. If the width W1 is larger than 3 mm, the internal volume of the sealed space may be small, and there is a risk that the steam flow path and the condensate flow path may not be sufficiently secured. On the other hand, the width W1 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 W1 is smaller than 0.2 mm, there is a risk that the joint area may be insufficient when a positional deviation occurs during the joining of the first sheet and the second sheet. The range of the width W1 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. In addition, the range of the width W1 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values.

[0030] In addition, holes 13a penetrating in the thickness direction (z direction) are provided at the four corners of the outer periphery joint portion 13 of the main body 11. These holes 13a function as positioning means when the second sheet 20 is superimposed.

[0031] The peripheral liquid flow path section 14 functions as a liquid flow path section and constitutes a part of the condensed liquid flow path 3, which is the second flow path through which the working fluid passes when condensed and liquefied. Fig. 6 shows the part indicated by the arrow I2 in Fig. 5, and Fig. 7 shows a cross section of the part cut along I3-I3 in Fig. 4. Both figures show the cross-sectional shape of the peripheral liquid flow path section 14. Fig. 8 shows an enlarged plan view of the peripheral liquid flow path section 14 as seen from the direction indicated by the arrow I4 in Fig. 6.

[0032] As can be seen from these figures, the peripheral liquid flow path section 14 is formed along the inside of the peripheral joint section 13 on the inner surface 10a of the main body 11, and is provided along the outer periphery of the sealed space 2. The peripheral liquid flow path section 14 is also formed with liquid flow path grooves 14a, which are multiple grooves extending parallel to the outer periphery direction of the main body 11, and the multiple liquid flow path grooves 14a are arranged at predetermined intervals in a direction different from the direction in which the liquid flow path grooves 14a extend. Therefore, as can be seen from Figures 6 and 7, the peripheral liquid flow path section 14 has liquid flow path grooves 14a, which are recesses, and protrusions 14b between the liquid flow path grooves 14a, which are repeated on the inner surface 10a side in the cross section. The liquid flow passage groove 14a is a groove formed by laminating the inner layer 10d on the inside of a groove formed in the outer layer 10e.

[0033] By providing a plurality of liquid flow path grooves 14a in this manner, the depth and width of each liquid flow path groove 14a can be reduced, and the flow path cross-sectional area of ​​the condensate flow path 3 (see FIG. 20, etc.), which is the second flow path, can be reduced, making it possible to utilize a large capillary force. On the other hand, by providing a plurality of liquid flow path grooves 14a, the total flow path cross-sectional area of ​​the condensate flow path 3 as a whole can be ensured to be an appropriate size, and the condensate can flow at a required flow rate.

[0034] Here, since the liquid flow path groove 14a is a groove, its cross-sectional shape has a bottom provided on the outer surface 10b side, and an opening provided on the inner surface 10a side opposite to the bottom. In this embodiment, the liquid flow path groove 14a has a semi-elliptical cross section. However, the cross-sectional shape is not limited to a semi-elliptical shape, and may be a circle, a rectangle, a square, a trapezoid, or another polygon, or a combination of any two or more of these.

[0035] 8, in the peripheral liquid flow path portion 14, adjacent liquid flow path grooves 14a communicate with each other through communication openings 14c at a predetermined interval. This promotes equalization of the amount of condensed liquid between the multiple liquid flow path grooves 14a, allowing the condensed liquid to flow efficiently and enabling smooth return of the working fluid. In this embodiment, the communication openings 14c are arranged so as to face each other at the same position in the extension direction of one liquid flow channel 14a, sandwiching the groove, as shown in Fig. 8. However, this is not limited to this, and the communication openings 14c may be arranged at different positions in the extension direction of one liquid flow channel 14a, sandwiching the groove, as shown in Fig. 9, for example. In other words, the protrusions 14b and the communication openings 14c may be arranged alternately in a direction perpendicular to the extension direction of the liquid flow channel.

[0036] Other configurations, for example, as shown in Figures 10 to 12, are also possible. Figures 10 to 12 show one condensate flow path 14a, two convex portions 14b sandwiching it, and one communication opening 14c provided in each convex portion 14b, from the same viewpoint as Figure 8. In all of these, the shapes of the convex portion 14b and the communication opening 14c from that viewpoint (plan view) are different from those in the example of Figure 8. That is, in the protrusion 14b shown in Fig. 8, the width at the end where the communication opening 14c is formed is the same as that at other portions and is constant. In contrast, in the protrusion 14b shaped as shown in Figs. 10 to 12, the width at the end where the communication opening 14c is formed is formed to be smaller than the maximum width of the protrusion 14b. More specifically, in the example of Fig. 10, the corner at the end is made arc-shaped and R is formed at the corner, so that the width of the end is reduced, in Fig. 11, the end is made semicircular, so that the width of the end is reduced, and in Fig. 12, the end is tapered to be pointed.

[0037] As shown in Figures 10 to 12, the width of the end of the convex portion 14b where the communicating opening 14c is formed is formed to be smaller than the maximum width of the convex portion 14b, which makes it easier for the working fluid to move through the communicating opening 14c and facilitates the movement of the working fluid to the adjacent condensate flow path 3.

[0038] The peripheral liquid flow path section 14 having the above-mentioned configuration preferably further has the following configuration. The width of the outer peripheral liquid flow passage portion 14 indicated by W2 in FIG. 4 to FIG. 7 (the size in the direction in which the liquid flow passage grooves 14a are arranged, and the width at the joint surface with the second sheet 20) can be appropriately set based on the size of the entire vapor chamber, etc., but the width W2 is preferably 3.0 mm or less, and may be 1.5 mm or less, or may be 1.0 mm or less. If the width W2 exceeds 3.0 mm, there is a risk that the space for the inner liquid flow passage and the vapor flow passage will not be sufficient. On the other hand, the width W2 is preferably 0.1 mm or more, and may be 0.2 mm or more, or may be 0.4 mm or more. If the width W2 is smaller than 0.1 mm, there is a risk that the amount of liquid circulating outside will not be sufficient. The range of the width W2 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. The range of the width W2 may also be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. The width W2 may be the same as the width W9 (see FIG. 17) of the outer peripheral liquid flow path portion 24 of the second sheet 20, or may be larger or smaller.

[0039] Regarding the liquid flow path grooves 14a, the groove width (the size in the direction in which the liquid flow path grooves 14a are arranged, the width at the opening surface of the groove) indicated by W3 in FIG. 6 and FIG. 8 is preferably 1000 μm or less, and may be 500 μm or less, or may be 200 μm or less. On the other hand, the width W3 is preferably 20 μm or more, and may be 45 μm or more, or may be 60 μm or more. The range of the width W3 may be determined by a combination of any one of the multiple upper limit candidate values ​​and any one of the multiple lower limit candidate values. The range of the width W3 may also be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. Moreover, the depth of the groove indicated by D1 in FIG. 6 and FIG. 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 D1 is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. The range of the depth D1 may be determined by a combination of any one of the above-mentioned multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Moreover, the range of the depth D1 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. With the above-mentioned configuration, the capillary force of the condensate flow passage, which is necessary for reflux, can be more strongly exerted.

[0040] From the viewpoint of exerting a stronger capillary force in the condensate flow path, the aspect ratio (length-to-length ratio) of the flow path cross section, which is expressed by dividing the width W3 by the depth D1, is preferably greater than 1.0. This ratio may be 1.5 or more, or may be 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, it is preferable that W3 is larger than D1, and from this viewpoint, it is preferable that the aspect ratio is larger than 1.3.

[0041] Furthermore, the pitch between adjacent liquid flow path grooves 14a in the plurality of liquid flow path grooves 14a is preferably 1100 μm or less, and 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, and may be 55 μm or more, or may be 70 μm or more. This pitch range may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. Furthermore, the pitch range may be determined by a combination of any two of the plurality of upper limit candidate values, or a combination of any two of the plurality of lower limit candidate values. This makes it possible to increase the density of the condensate flow passages while suppressing the condensate flow passages from being crushed due to deformation during joining or assembly.

[0042] Regarding the communication opening 14c, the size of the opening along the direction in which the liquid flow path groove 14a extends, indicated by L1 in FIG. 8, is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. On the other hand, the size L1 is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. The range of the size L1 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, the range of the size L1 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values.

[0043] 8, the pitch between adjacent communication openings 14c in the direction in which the liquid flow path groove 14a extends is preferably 2700 μm or less, may be 1800 μm or less, or may be 900 μm or less. On the other hand, this pitch L2 is preferably 60 μm or more, may be 110 μm or more, or may be 140 μm or more. The range of this pitch L2 may be determined by a combination of any one of the multiple upper limit candidate values ​​and any one of the multiple lower limit candidate values. Also, the range of the pitch L2 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values.

[0044] Returning to Figs. 1 to 5, the inner liquid flow path section 15 will be described. The inner liquid flow path section 15 also functions as a liquid flow path section, and is a portion that constitutes a part of the condensed liquid flow path 3, which is the second flow path through which the working fluid passes when condensed and liquefied. Fig. 13 shows the part indicated by I4 in Fig. 5. This figure also shows the cross-sectional shape of the inner liquid flow path section 15. Fig. 14 shows an enlarged plan view of the inner liquid flow path section 15 as seen from the direction indicated by arrow I5 in Fig. 13.

[0045] As can be seen from these figures, the inner liquid flow path section 15 is a wall formed on the inner surface 10a of the main body 11, inside the annular ring of the outer peripheral liquid flow path section 14. As can be seen from Figures 3 and 4, the inner liquid flow path section 15 in this embodiment is a wall that is rectangular in plan view of the main body 11 and extends in a direction parallel to the long side (x direction), and multiple (three in this embodiment) inner liquid flow path sections 15 are arranged at predetermined intervals in a direction parallel to the short side (y direction). Each inner liquid flow passage section 15 is formed with liquid flow passage grooves 15a that are parallel to the direction in which the inner liquid flow passage section 15 extends, and multiple liquid flow passage grooves 15a are arranged at predetermined intervals in a direction different from the direction in which the liquid flow passage grooves 15a extend. Therefore, as can be seen from Figures 5 and 13, in the inner liquid flow passage section 15, the liquid flow passage grooves 15a that are recesses and the protrusions 15b between the liquid flow passage grooves 15a are formed in a repeated manner on the inner surface 10a side in the cross section. Note that the liquid flow passage grooves 15a are formed by laminating the inner layer 10d on the inside of a groove formed in the outer layer 10e.

[0046] By providing a plurality of liquid flow path grooves 15a in this manner, the depth and width of each liquid flow path groove 15a can be reduced, and the flow path cross-sectional area of ​​the condensate flow path 3 (see FIG. 20, etc.) serving as the second flow path can be reduced, making it possible to utilize a large capillary force. On the other hand, by providing a plurality of liquid flow path grooves 15a, the total flow path cross-sectional area of ​​the condensate flow path 3 as a whole can be ensured to be of an appropriate size, and the condensate can flow at a required flow rate.

[0047] Here, since the liquid flow path groove 15a is a groove, its cross-sectional shape has a bottom provided on the outer surface 10b side, and an opening provided on the inner surface 10a side at the opposite side facing the bottom. In this embodiment, the liquid flow path groove 15a has a semi-elliptical cross section, but the cross-sectional shape is not limited to a semi-elliptical shape and may be a circle, a rectangle, a square, a trapezoid, or another polygon, or a combination of any two or more of these.

[0048] 14, adjacent liquid flow grooves 15a are connected to each other through communication openings 15c at a predetermined interval. This promotes equalization of the amount of condensed liquid between the multiple liquid flow grooves 15a, allowing the condensed liquid to flow efficiently, enabling smooth return of the working fluid. As with the communicating opening 14c, the communicating opening 15c may have the protrusions 15b and the communicating openings 15c arranged alternately in a direction perpendicular to the direction in which the liquid flow path groove 15a extends, following the example shown in Fig. 9. Also, the communicating openings 15c and the protrusions 15b may have shapes following the examples in Figs. 10 to 12.

[0049] The inside liquid flow path section 15 having the above-mentioned configuration preferably further has the following configuration. The width of the inner liquid flow path section 15 (the size in the direction in which the inner liquid flow path section 15 and the steam flow path grooves 16 are arranged, and the width at the joint surface with the second sheet 20) indicated by W4 in Figs. 4, 5, and 13 is preferably 3000 µm or less, and may be 1500 µm or less, or may be 1000 µm or less. On the other hand, this width W4 is preferably 100 µm or more, and may be 200 µm or more, or may be 400 µm or more. The range of this width W4 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. In addition, the range of the width G may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. The width W4 is the width W 10 (see FIG. 17), or may be larger or smaller. In this embodiment, they are considered to be the same.

[0050] Moreover, the pitch of the multiple inner liquid flow path sections 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 determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Moreover, the pitch range may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. This reduces the flow resistance of the steam flow path, and allows a good balance between the movement of steam and the return of condensate.

[0051] Regarding the liquid flow path grooves 15a, the groove width (the size in the direction in which the liquid flow path grooves 15a are arranged, and the width at the opening surface of the groove) indicated by W5 in FIG. 13 and FIG. 14 is preferably 1000 μm or less, and may be 500 μm or less, or may be 200 μm or less. On the other hand, this width W5 is preferably 20 μm or more, and may be 45 μm or more, or may be 60 μm or more. The range of this width W5 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, the range of the width W5 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. Moreover, the depth of the groove indicated by D2 in FIG. 13 is preferably 200 μm or less, may be 150 μm or less, or may be 100 μm or less. On the other hand, this depth D2 is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. The range of this depth D2 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Moreover, the range of the depth D2 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. This makes it possible to exert a strong capillary force in the condensate flow passage, which is necessary for reflux.

[0052] From the viewpoint of exerting a stronger capillary force in the flow channel, the aspect ratio (horizontal to vertical ratio) in the flow channel cross section, which is expressed by the value obtained by dividing the width W5 by the depth D2, is preferably greater than 1.0. It may be 1.5 or more, or 2.0 or more, or it may be less than 1.0, 0.75 or less, or 0.5 or less. Among these, from the viewpoint of manufacturing, it is preferable that width W5 is larger than depth D2, and from this viewpoint, it is preferable that the aspect ratio is larger than 1.3.

[0053] In addition, the pitch between adjacent liquid flow path grooves 15a in the plurality of liquid flow path grooves 15a is preferably 1100 μm or less, and 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, and may be 55 μm or more, or may be 70 μm or more. This pitch range may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. In addition, the pitch range may be determined by a combination of any two of the plurality of upper limit candidate values, or a combination of any two of the plurality of lower limit candidate values. This makes it possible to increase the density of the condensate flow passages while suppressing deformation and collapse of the flow passages during bonding or assembly.

[0054] Furthermore, the size of the communication opening 15c along the direction in which the liquid flow path groove 15a extends, indicated by L3 in FIG. 14, is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. On the other hand, this size L3 is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. The range of this size L3 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, the range of size L3 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. In addition, the pitch between adjacent communication openings 15c in the direction in which the liquid flow path groove 15a extends, indicated by L4 in FIG. 14, is preferably 2700 μm or less, may be 1800 μm or less, or may be 900 μm or less. On the other hand, this pitch L4 is preferably 60 μm or more, may be 110 μm or more, or may be 140 μm or more. The range of this pitch L4 may be determined by a combination of any one of the multiple upper limit candidate values ​​and any one of the multiple lower limit candidate values. In addition, the range of this pitch L4 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values.

[0055] In the above-described embodiment, the liquid flow path grooves 14a and liquid flow path grooves 15a are arranged parallel to each other and spaced apart at equal intervals, but this is not limited to this, and as long as capillary action can be achieved, the pitch between the grooves may vary, and the grooves do not have to be parallel to each other.

[0056] Next, the steam flow passage groove 16 will be described. The steam flow passage groove 16 is a portion through which the vaporized steam generated when the working fluid evaporates passes, and constitutes a part of the steam flow passage 4 (see FIG. 19, etc.), which is the first flow passage. The shape of the steam flow passage groove 16 in a plan view is shown in FIG. 4, and the cross-sectional shape of the steam flow passage groove 16 is shown in FIG. 5.

[0057] As can be seen from these figures, the steam flow path groove 16 is formed as a groove formed on the inner surface 10a of the main body 11, inside the ring of the outer peripheral liquid flow path section 14. More specifically, the steam flow path groove 16 in this embodiment is formed between adjacent inner liquid flow path sections 15 and between the outer peripheral liquid flow path section 14 and the inner liquid flow path section 15, and is a groove extending in a direction parallel to the long side (x direction) of a rectangle in a plan view of the main body 11. A plurality of steam flow path grooves 16 (four in this embodiment) are arranged in a direction parallel to the short side (y direction). Therefore, as can be seen from FIG. 5, the first sheet 10 has a shape in which the walls of the outer peripheral liquid flow path section 14 and the inner liquid flow path section 15 are convex and the steam flow path grooves 16 are concave in the y direction, with the concaves and convexes being repeated. Here, since the steam flow passage groove 16 is a groove, in its cross-sectional shape, it has a bottom portion on the outer surface 10b side, and an opening on the inner surface 10a side opposite to the bottom portion. The steam flow passage groove 16 is a groove formed by laminating an inner layer 10d on the inside of a groove formed in the outer layer 10e.

[0058] The steam flow passage groove 16 having such a configuration preferably further has the following configuration. The width of the steam flow path groove 16 indicated by W6 in Figures 4 and 5 (the size in the direction in which the inner liquid flow path section 15 and the steam flow path groove 16 are arranged, and the width at the opening surface of the groove) is formed to be at least larger than the width W3 of the liquid flow path groove 14a and the width W5 of the liquid flow path groove 15a described above, and is preferably 2000 μm or less, may be 1500 μm or less, or may be 1000 μm or less. On the other hand, this width W6 is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. The range of this width W6 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, the range of width W6 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. It may be determined by any two combinations of candidate values. The pitch of the steam flow passage grooves 16 is usually determined by the pitch of the inner liquid flow passage portions 15 . On the other hand, the depth of the vapor flow path groove 16 shown by D3 in FIG. 5 is formed to be greater than at least the depth D1 of the liquid flow path groove 14a and the depth D2 of the liquid flow path groove 15a, and is preferably 300 μm or less, may be 200 μm or less, or may be 100 μm or less. On the other hand, this depth D3 is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of this depth D3 may be determined by a combination of any one of the above-mentioned multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, the range of the depth D3 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. In this way, by making the flow path cross-sectional area of ​​the steam flow path groove larger than the flow path cross-sectional area of ​​the liquid flow path groove, it is possible to smoothly circulate steam, which has a larger volume than condensed liquid due to the nature of the working fluid.

[0059] In this embodiment, the cross-sectional shape of the steam flow passage groove 16 is semi-elliptical, but it may be rectangular, square, trapezoid or other quadrangular, triangular, semicircular, semicircular at the bottom, semi-elliptical at the bottom, or a combination of any two or more of these. The steam flow passage can reduce the flow resistance of the steam to allow smooth return of the working fluid, so the shape of the flow passage cross section can be determined from this viewpoint.

[0060] In this embodiment, an example has been described in which one steam flow path groove 16 is formed between adjacent inner liquid flow path sections 15, but this is not limited to this, and the embodiment may also be one in which two or more steam flow path grooves are arranged side by side between adjacent inner liquid flow path sections. Also, so long as the second sheet 20 has steam flow passage grooves, the first sheet 10 may have no steam flow passage grooves in part or in its entirety.

[0061] The steam flow passage communication grooves 17 are grooves that communicate the multiple steam flow passage grooves 16. This allows the steam in the multiple steam flow passage grooves 16 to be equalized, and the steam to be transported over a wider area, allowing many condensate flow passages 3 to be used efficiently, making it possible to more smoothly return the working fluid.

[0062] As can be seen from Figures 3 and 4, the steam flow path communication groove 17 in this embodiment is formed between both ends in the direction in which the inner liquid flow path section 15 and the steam flow path groove 16 extend, and the outer circumferential liquid flow path section 14. Figure 7 shows a cross section taken along the line indicated by I3-I3 in Figure 4, which is perpendicular to the communication direction of the steam flow path communication groove 17. 2 to 4, for ease of understanding, a dotted line is added to a portion that should be a boundary between the steam flow passage groove 16 and the steam flow passage communication groove 17. However, this line is not necessarily a line that appears according to the shape, but is an imaginary line added for ease of understanding.

[0063] The steam flow passage communication groove 17 is only required to be formed so as to communicate the adjacent steam flow passage grooves 16, and the shape thereof is not particularly limited. For example, the steam flow passage communication groove 17 may have the following configuration. The width of the steam flow passage communication groove 17 (the size in the direction perpendicular to the communication direction, the width at the opening surface of the groove) indicated by W7 in FIG. 4 and FIG. 7 is preferably 1000 μm or less, may be 750 μm or less, or may be 500 μm or less. On the other hand, this width W7 is preferably 100 μm or more, may be 150 μm or more, or may be 200 μm or more. The range of this width W7 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, the range of the width W7 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. 7, the depth of the steam flow passage communication groove 17 is preferably 300 μm or less, may be 225 μm or less, or may be 150 μm or less. On the other hand, the depth D4 is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of the depth D4 may be determined by a combination of any one of the multiple upper limit candidate values ​​and any one of the multiple lower limit candidate values. The range of the depth D4 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values.

[0064] In this embodiment, the cross-sectional shape of the steam flow path connecting groove 17 is semi-elliptical, but is not limited to this, and may be rectangular, square, trapezoid or other quadrangular, triangular, semicircular, with a semicircular bottom, with a semi-elliptical bottom, or a combination of any two or more of these. The steam flow passage communication grooves can reduce the flow resistance of the steam, thereby enabling the working fluid to return smoothly, and therefore the shape of the flow passage cross section can also be determined from this viewpoint. The steam flow passage communication groove 17 is also a groove formed in the outer layer 10e and the inner layer 10d laminated on the inside of the groove.

[0065] In this embodiment, the outer surface 10b of the main body 11 is configured to be a flat surface. This can improve adhesion to a member that should be in close contact with the outer surface 10b (for example, an electronic component to be cooled, or a housing of an electronic device to which heat should be transferred, etc.). However, the shape of the outer surface 10b is not limited to this, and may have irregularities depending on the purpose. Here, the outer surface 10b does not have a shape corresponding to the inner surface 10a, but has a shape that allows the outer surface 10b to contribute to the intended heat transfer, etc. As described above, the outer surface 10b is formed by the outer layer 10e. Therefore, the thickness of the outer layer 10e varies depending on the position in the x direction and the position in the y direction. Such inner surface 10a, outer surface 10b, and the inner layer 10d and outer layer 10e that constitute them make it possible to form a desired flow path in the vapor chamber while making it thin, and to suppress deformation or damage to the vapor chamber due to forces such as external impact, expansion due to solidification of the working fluid by low-temperature freezing, and vapor pressure during operation.

[0066] Next, the second sheet 20 will be described. In this embodiment, the second sheet 20 is also a sheet-like member as a whole. Fig. 15 shows a perspective view of the second sheet 20 seen from the inner surface 20a side, and Fig. 16 shows a plan view of the second sheet 20 seen from the inner surface 20a side. Fig. 17 shows a cut surface of the second sheet 20 when cut along I6-I6 in Fig. 16. Fig. 18 shows a cut surface of the second sheet 20 when cut along I7-I7 in Fig. 16. 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, and a pattern is formed for the working fluid to return to the inner surface 20a side. As 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 the sealed space 2 is formed by sealing the working fluid therein.

[0067] 16 and 17, in this embodiment, the second sheet 20 is configured to have an inner layer 20d made of a material that forms the inner surface 20a, and an outer layer 20e made of a material that forms the outer surface 20b. That is, the second sheet 20 is configured by laminating a plurality of layers, one of which forms the inner surface 20a and the other layers form the outer surface 20b. In this embodiment, the side surface 20c is formed by an end surface of the inner layer 20d and an end surface of the outer layer 20e.

[0068] Here, the inner surface 20a side of the second sheet 20 is provided with a pattern for the working fluid to move, and the inner layer 20d constitutes the surface of this pattern that comes into direct contact with the working fluid. For this reason, the inner layer 20d is preferably made of a material that is chemically stable with respect to the working fluid and has high thermal conductivity. For this reason, for example, copper and copper alloys can be used. In particular, by using copper and copper alloys, it is possible to improve the heat transport capacity while suppressing reactions with the working fluid (particularly water), and further to facilitate the fabrication of a vapor chamber by etching and diffusion bonding as described below.

[0069] The outer layer 20e is laminated on the inner surface 20a side of the inner layer 20d, and forms the outer surface 20b. The outer layer 20e has a pattern formed on the inner surface 20a of the second sheet 20 on the side in contact with the inner layer 20d. However, as described above, the patterned portion of the outer layer 20e forms a flow path, but is covered by the inner layer 20d and is prevented from coming into direct contact with the working fluid. That is, the outer layer 20e has a groove that serves as the flow path, and the inner layer 20d is laminated inside the groove.

[0070] On the other hand, in this embodiment, the surface of the outer layer 20e that will become the outer surface 20b is made flat or slightly uneven, taking into consideration contact with parts disposed in the vapor chamber 1. Therefore, in this embodiment, the outer layer 20e is configured so that the distance (ie, thickness) between the surface of the outer layer 20e that is in contact with the inner layer 20d on the inner surface 20a side and the outer surface 20b varies depending on the position in the x direction and the position in the y direction. As a result, even if the vapor chamber is thinned while forming a flow path, it can have the strength required as a vapor chamber.

[0071] Therefore, it is preferable that the outer layer 20e is made of a material having a higher strength than the inner layer 20d. Specifically, it is preferable that the 0.2% yield strength or upper yield point of the outer layer 20e is greater than the 0.2% yield strength or upper yield point of the inner layer 20d. There are no particular limitations as long as this is satisfied, but in order to achieve higher strength, the 0.2% yield strength or upper yield point of the outer layer 20e is preferably 100 MPa or more, and more preferably 200 MPa or more. This makes it possible to reduce deformation or damage to the vapor chamber due to forces such as external impacts, expansion due to solidification of the working fluid caused by low-temperature freezing, and vapor pressure during operation, even when the desired flow path is formed in the vapor chamber and made thin. Furthermore, since the outer layer 20e can improve the strength of the vapor chamber in this manner, the strength constraints on the pattern of the flow path through which the working fluid moves, formed on the inner surface 20a, can be relaxed, making it possible to design with a focus on improving thermal performance, which can be said to be advantageous from the standpoint of thermal performance as well.

[0072] The material constituting the outer layer 20e is not particularly limited, but from the viewpoint of heat diffusion, it is preferable that the thermal conductivity is high, and preferably 10 W / m·K or more. From this viewpoint, examples of the material constituting the outer layer 20e include iron-based materials such as stainless steel, invar, and kovar, titanium alloys, and nickel alloys. Also, composite materials containing fine particles of diamond, alumina, silicon carbide, etc. in these metals may be used.

[0073] The thickness of the inner layer 20d is not particularly limited in consideration of the specifications, but is preferably 5 μm or more and 20 μm or less. If the inner layer 20d is thinner than 5 μm, the possibility that the material of the outer layer 20e and the working fluid will affect each other increases. On the other hand, if the inner layer 20d is thicker than 20 μm, there is a high possibility that difficulties will arise from the viewpoint of manufacturing, that it will be difficult to meet the required thickness specifications including in-plane variations, and that the surface will become rough.

[0074] On the other hand, the thickness of the outer layer 20e is not particularly limited since it depends on the specifications, but it is preferable that the thickness is 0.02 mm or more and 0.5 mm or less at any part. If the outer layer 20e has a part thinner than 0.02 mm, the effect of suppressing deformation may be reduced, and if the outer layer 20e has a part thicker than 0.5 mm, the heat transfer from the vapor chamber to the outside may be hindered or it may be difficult to meet the thickness specifications.

[0075] The thickness of the second sheet 20 is the sum of the inner layer 20d and the outer layer 20e, but the specific thickness is not particularly limited. However, it is preferably 1.0 mm or less, and may be 0.75 mm or less, or 0.5 mm or less. On the other hand, this thickness is preferably 0.02 mm or more, and may be 0.05 mm or more, or may be 0.1 mm or more. This thickness range may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, this thickness range may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. This increases the number of situations in which it can be used as a thin vapor chamber. Even when the vapor chamber is thinned while having the desired flow path, it is possible to suppress deformation or damage to the vapor chamber due to external impacts, expansion caused by solidification of the working fluid by low-temperature freezing, and forces caused by vapor pressure during operation. Furthermore, the first sheet 10 and the second sheet 20 may have the same thickness or different thicknesses.

[0076] Such a second sheet 20 includes a main body 21 and an injection portion 22. The main body 21 is a sheet-like portion that forms a portion where the working fluid circulates, and in this embodiment, is a rectangle with arcs (so-called R) formed at the corners in a plan view. However, the main body 21 of the second sheet 20 may be a rectangle as in this embodiment, a circle, an ellipse, a triangle, or another polygon, or a shape having a bent portion, such as an L-shape, a T-shape, a crank shape, etc. Also, it may be a shape that combines at least two of these shapes.

[0077] The injection section 22 is a section where the working fluid is injected into the hollow section formed by the first sheet 10 and the second sheet 20 to form the sealed space 2 (see FIG. 19), and in this embodiment, is a sheet-like shape that is quadrangular in plan view and protrudes from one side of the main body 21 that is rectangular in plan view. In this embodiment, an injection groove 22a is formed on the inner surface 20a side of the injection section 22 of the second sheet 20, and the side surface 20c of the second sheet 20 communicates with the outside and inside of the main body 21 (the hollow section, the section that will become the sealed space 2).

[0078] A structure for the working fluid to circulate is formed on the inner surface 20a side of the main body 21. Specifically, the inner surface 20a side of the main body 21 is provided with an outer periphery joining portion 23, an outer periphery liquid flow path portion 24, an inner liquid flow path portion 25, a steam flow path groove 26, and a steam flow path connecting groove 27.

[0079] The outer peripheral joining portion 23 is a surface formed on the inner surface 20a side of the main body 21 along the outer periphery of the main body 21. This outer peripheral joining portion 23 overlaps and is joined (by diffusion bonding, brazing, etc.) to the outer peripheral joining portion 13 of the first sheet 10, thereby forming a hollow portion between the first sheet 10 and the second sheet 20, and a working fluid is sealed in this hollow portion to form the sealed space 2. 16 to 18, the width of the peripheral joint 23 (the size in the direction perpendicular to the direction in which the peripheral joint 23 extends, and the width at the joint surface with the first sheet 10) is preferably the same as the width W1 of the peripheral joint 13 of the main body 11 described above. However, it is not limited to this and may be larger or smaller.

[0080] In addition, holes 23a penetrating in the thickness direction (z direction) are provided in the four corners of the outer periphery joint portion 23 of the main body 21. These holes 23a function as positioning means when overlapping with the first sheet 10.

[0081] The outer circumferential liquid flow path section 24 is a liquid flow path section, and is a portion that constitutes a part of the condensed liquid flow path 3, which is the second flow path through which the working fluid passes when it is condensed and liquefied.

[0082] The peripheral liquid flow path portion 24 is formed along the inside of the peripheral joint portion 23 on the inner surface 20a of the main body 21. In this embodiment, the peripheral liquid flow path portion 24 of the second sheet 20 is a flat surface and is flush with the peripheral joint portion 23 before being joined to the first sheet 10, as can be seen from Figures 17 and 18. This closes the openings of the multiple liquid flow path grooves 14a of the first sheet 10 described above, forming the condensate flow path 3, which is the second flow path. Detailed aspects of the combination of the first sheet 10 and the second sheet 20 will be described later. In this way, in the second sheet 20 of this embodiment, the outer peripheral bonding portion 23 and the outer peripheral liquid flow path portion 24 are flush with each other, so there is no structural boundary line that distinguishes the two. However, for ease of understanding, the boundary between the two is shown by a dotted line in Figures 15 and 16.

[0083] The outer circumferential liquid flow path section 24 preferably has the following configuration. The width of the peripheral liquid flow path section 24 shown by W9 in Figures 16 to 18 (the size in a direction perpendicular to the direction in which the peripheral liquid flow path section 24 extends, and the width at the joint surface with the first sheet 10) may be the same as the width W2 of the peripheral liquid flow path section 14 of the first sheet 10, or it may be larger or smaller.

[0084] Next, a description will be given of the inner liquid flow path section 25. The inner liquid flow path section 25 is also a liquid flow path section, and is one of the parts that constitute the condensed liquid flow path 3, which is the second flow path.

[0085] 15 to 18, the inner liquid flow path section 25 is formed on the inner surface 20a of the main body 21 inside the annular ring of the outer peripheral liquid flow path section 24. The inner liquid flow path section 25 in this embodiment is a wall that is rectangular in plan view of the main body 21 and extends in a direction parallel to the long side (x direction), and a plurality of inner liquid flow path sections 25 (three in this embodiment) are arranged at predetermined intervals in a direction parallel to the short side (y direction). In this embodiment, the surface of each inner liquid flow path portion 25 on the inner surface 20a side is formed as a flat surface before being joined to the first sheet 10. This closes the openings of the plurality of liquid flow path grooves 15a of the first sheet 10 described above, thereby forming the condensate liquid flow paths 3.

[0086] Figures 16 and 17 show the W 10 The width of the inner liquid flow path section 25 indicated by (the size in the direction in which the inner liquid flow path section 25 and the steam flow path grooves 26 are arranged, and the width at the joint surface with the first sheet 10) may be the same as the width W4 of the inner liquid flow path section 15 of the first sheet 10, or may be larger or smaller. In this embodiment, they are the same.

[0087] In this embodiment, each inner liquid flow path portion 25 is formed with a flat surface before bonding, but liquid flow path grooves may be formed in the same manner as in the first sheet. In that case, the liquid flow path grooves may be in the same position as each other in a plan view, or may be shifted from each other.

[0088] Next, the steam flow path groove 26 will be described. The steam flow path groove 26 is a portion through which the vaporized steam generated when the working fluid evaporates passes, and constitutes a part of the steam flow path 4, which is the first flow path. Fig. 16 shows the shape of the steam flow path groove 26 in a plan view, and Fig. 17 shows the cross-sectional shape of the steam flow path groove 26.

[0089] As can be seen from these figures, the steam flow path groove 26 is formed as a groove on the inner surface 20a of the main body 21, inside the ring of the outer peripheral liquid flow path section 24. More specifically, the steam flow path groove 26 in this embodiment is formed between adjacent inner liquid flow path sections 25 and between the outer peripheral liquid flow path section 24 and the inner liquid flow path section 25, and is a groove extending in a direction parallel to the long side (x direction) of a rectangle in a plan view of the main body 21. A plurality of steam flow path grooves 26 (four in this embodiment) are arranged in a direction parallel to the short side (y direction). Therefore, as can be seen from FIG. 17, the second sheet 20 has a shape in which projections due to the walls of the outer peripheral liquid flow path section 24 and the inner liquid flow path section 25 and depressions due to the grooves of the steam flow path groove 26 are repeated in the y direction. Here, since the steam flow passage groove 26 is a groove, its cross-sectional shape has a bottom portion on the outer surface 20b side, and an opening on the inner surface 20a side at a portion on the opposite side facing the bottom portion. The steam flow passage groove 26 is a groove formed in the outer layer 20e, and the inner layer 20d is laminated on the inner side of the groove.

[0090] The steam flow path groove 26 is preferably disposed at a position where, when combined with the first sheet 10, it overlaps in the thickness direction with the steam flow path groove 16 of the first sheet 10. In this way, the steam flow path groove 16 and the steam flow path groove 26 can form the steam flow path 4, which is the first flow path.

[0091] Figures 16 and 17 show the W 11 The width of the steam flow path groove 26 (the size in the direction in which the inner liquid flow path section 25 and the steam flow path groove 26 are arranged, and the width at the opening surface of the groove) shown in (a) may be the same as the width W6 of the steam flow path groove 16 of the first sheet 10, or it may be larger or smaller. Moreover, the depth of the steam flow passage groove 26 indicated by D5 in FIG. 17 is preferably 300 μm or less, may be 225 μm or less, or may be 150 μm or less. On the other hand, this depth D5 is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of this depth D5 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Moreover, the range of the depth D5 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. Furthermore, the depth of the steam flow passage grooves 16 in the first sheet 10 and the depth of the steam flow passage grooves 26 in the second sheet 20 may be the same, or may be greater or smaller.

[0092] In this embodiment, the cross-sectional shape of the steam flow passage groove 26 is semi-elliptical, but it may be rectangular, square, trapezoid or other quadrangular, triangular, semicircular, semicircular at the bottom, semi-elliptical at the bottom, or a combination of several of these. The steam flow passage can smoothly return the working fluid by reducing the flow resistance of the steam, so the shape of the flow passage cross section can also be determined from this viewpoint.

[0093] In this embodiment, an example has been described in which one steam flow path groove 26 is formed between adjacent inner liquid flow path sections 25, but this is not limited to this, and the embodiment may also be one in which two or more steam flow path grooves are arranged side by side between adjacent inner liquid flow path sections. Furthermore, so long as the first sheet 10 has steam flow passage grooves, the second sheet 20 may have no steam flow passage grooves in part or in its entirety.

[0094] The steam flow passage communication groove 27 is a groove that communicates the multiple steam flow passage grooves 26. This makes it possible to equalize the steam in the multiple steam flow passages 4, transport the steam over a wider range, and efficiently utilize many condensate flow passages 3, thereby making it possible to more smoothly return the working fluid.

[0095] 15, 16 and 18, the steam flow path communication groove 27 in this embodiment is formed between the end in the direction in which the inner liquid flow path section 25 and the steam flow path groove 26 extend, and the outer circumferential liquid flow path section 24. Also, Fig. 18 shows a cross section perpendicular to the communication direction of the steam flow path communication groove 27.

[0096] Figures 16 and 18 show the W 12 The width of the steam flow passage communication groove 27 indicated by D6 (the size in the direction perpendicular to the communication direction, the width at the opening surface of the groove) may be the same as the width W7 of the steam flow passage communication groove 17 of the first sheet 10, or may be larger or smaller. The depth of the steam flow passage communication groove 27 indicated by D6 in FIG. 18 is preferably 300 μm or less, may be 225 μm or less, or may be 150 μm or less. On the other hand, this depth D6 is preferably 10 μm or more, may be 25 μm or more, or may be 50 μm or more. The range of this depth D6 may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. The range of the depth D6 may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. Furthermore, the depth of the steam flow passage communicating grooves 17 of the first sheet 10 and the depth of the steam flow passage communicating grooves 27 of the second sheet 20 may be the same, or may be greater or smaller.

[0097] In this embodiment, the cross-sectional shape of the steam flow passage communication groove 27 is a semi-ellipse, but it is not limited thereto and may be a rectangle, a square, a quadrangle such as a trapezoid, a triangle, a semicircle, a shape with a semicircle at the bottom, a shape with a semi-ellipse at the bottom, or a combination of these shapes. Since the steam flow passage can allow smooth return by reducing the flow resistance of the steam, the shape of the flow passage cross section can also be determined from this viewpoint. The steam flow passage communicating groove 27 is also a groove formed in the outer layer 20e and the inner layer 20d laminated on the inside of this groove.

[0098] In this embodiment, the outer surface 20b of the main body 21 is configured to be a flat surface. This can improve adhesion to a member that should be in close contact with the outer surface 20b (for example, an electronic component to be cooled, or a housing of an electronic device to which heat should be transferred, etc.). However, the shape of the outer surface 20b is not limited to this, and may have irregularities depending on the purpose. Here, the outer surface 20b does not have a shape corresponding to the inner surface 20a, but has a shape that allows the outer surface 20b to contribute to the intended heat transfer, etc. The outer surface 20b is formed by the outer layer 20e as described above. Therefore, the thickness of the outer layer 20e varies depending on the position in the x direction and the position in the y direction. Such inner surface 20a, outer surface 20b, and the inner layer 20d and outer layer 20e that constitute them make it possible to form a desired flow path in the vapor chamber while making it thin, and to suppress deformation or damage to the vapor chamber due to forces such as external impact, expansion due to solidification of the working fluid by low-temperature freezing, and vapor pressure during operation.

[0099] Next, a description will be given of the structure when the first sheet 10 and the second sheet 20 are combined to form the vapor chamber 1. This description will provide a further understanding of the arrangement, size, shape, etc. of each component of the first sheet 10 and the second sheet 20. Fig. 19 shows a cross section of the vapor chamber 1 cut in the thickness direction along the y direction indicated by I8-I8 in Fig. 1. This figure is a combination of the diagram of the first sheet 10 shown in Fig. 5 and the diagram of the second sheet 20 shown in Fig. 17, showing the cross section of the vapor chamber 1 at this portion. Figure 20 shows an enlarged view of the part indicated by I9 in Figure 19, and Figure 21 shows the part indicated by I 10 -I 10 18 shows a cross section of the vapor chamber 1 cut in the thickness direction along the x direction indicated by the arrows 11 and 11. This figure shows the cross section of the vapor chamber 1 at this portion by combining the diagram of the first sheet 10 shown in FIG. 7 and the diagram of the second sheet 20 shown in FIG. 18.

[0100] 1, 2, and 19 to 21, the first sheet 10 and the second sheet 20 are arranged so as to overlap and are joined to form the vapor chamber 1. At this time, the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20 are arranged so as to face each other, the main body 11 of the first sheet 10 and the main body 21 of the second sheet 20 overlap, and the injection section 12 of the first sheet 10 and the injection section 22 of the second sheet 20 overlap. In other words, the inner layer 10d of the first sheet 10 and the outer layer 20e of the second sheet 20 overlap. 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 position of the hole 13a of the first sheet 10 with the position of the hole 23a of the second sheet 20.

[0101] By using such a laminate of the first sheet 10 and the second sheet 20, the components provided in the main body 11 and the main body 21 are arranged as shown in Figures 19 to 21. Specifically, they are as follows.

[0102] The first sheet 10 and the second sheet 20 are disposed so that their outer peripheral joining portions 13 and 23 overlap each other, and are joined together by a joining means such as diffusion bonding or brazing. As a result, a hollow space is formed between the first sheet 10 and the second sheet 20, and a working fluid is sealed in the hollow space to form the sealed space 2.

[0103] The outer circumferential liquid flow path section 14 of the first sheet 10 and the outer circumferential liquid flow path section 24 of the second sheet 20 are arranged so as to overlap with each other. As a result, the liquid flow path grooves 14a of the outer circumferential liquid flow path section 14 and the outer circumferential liquid flow path section 24 form a condensed liquid flow path 3, which is a second flow path in the hollow section through which condensed liquid, which is the working fluid that has been condensed and liquefied, flows. Similarly, the inner liquid flow path section 15 of the first sheet 10 and the inner liquid flow path section 25 of the second sheet 20 are arranged to overlap each other. As a result, the liquid flow path grooves 15a of the inner liquid flow path section 15 and the inner liquid flow path section 25 form a condensate flow path 3, which is a second flow path through which the condensate flows, in the hollow section. By forming a thin flow path surrounded by walls on all four sides in cross section, the condensate is moved by strong capillary force, enabling smooth circulation. In other words, when considering a flow path through which the condensate is assumed to flow, the condensate flow path 3 can obtain a high capillary force compared to a so-called groove flow path in which one side of the flow path is continuously open. Moreover, since the condensate flow passage 3 is formed separately from the steam flow passage 4 which is the first flow passage, it is possible to ensure smooth circulation of the working fluid. Furthermore, since the adjacent condensate flow paths 3 communicate with each other through the communication openings 14c and 15c, the condensate is made uniform and the circulation of the working fluid is made smoother.

[0104] In order to enhance the capillary force of the condensate flow path 3, the aspect ratio of the cross section of the flow path, which is expressed by dividing the flow path width by the flow path height, is preferably greater than 1.0. This ratio may be 1.5 or more, or may be 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, it is preferable that the channel width is larger than the channel height, and from this viewpoint, the aspect ratio is preferably larger than 1.3.

[0105] On the other hand, as can be seen from Figures 19 and 20, the opening of the steam flow path groove 16 in the first sheet 10 and the opening of the steam flow path groove 26 in the second sheet 20 overlap facing each other to form a flow path, which becomes the steam flow path 4, which is the first flow path through which steam flows. The flow passage cross-sectional area of ​​the condensate flow passage 3, which is the second flow passage, is smaller than the flow passage cross-sectional area of ​​the steam flow passage 4, which is the first flow passage. More specifically, the average flow passage cross-sectional area of ​​two adjacent steam flow passages 4 (flow passages formed by one steam flow passage groove 16 and one steam flow passage groove 26 in this embodiment) is set to A g The average cross-sectional area of ​​the plurality of condensate flow paths 3 (the plurality of condensate flow paths 3 formed by one inner liquid flow path portion 15 and one inner liquid flow path groove 25 in this embodiment) arranged between the two adjacent steam flow paths 4 is defined as Al Then, the condensate flow path 3 and the steam flow path 4 are A l A g The relationship is 0.5 times or less, and preferably 0.25 times or less, so that the working fluid can easily selectively pass through the first flow path and the second flow path depending on its phase (gas phase, liquid phase). This relationship needs to be satisfied in at least a portion of the entire vapor chamber, and it is more preferable that this relationship be satisfied in the entire vapor chamber.

[0106] As can be seen from FIG. 21, the opening of the steam flow passage communication groove 17 of the first sheet 10 and the opening of the steam flow passage communication groove 27 of the second sheet 20 overlap to face each other, thereby forming a flow passage.

[0107] On the other hand, as shown in Figures 1 and 2, the inner surfaces 10a, 20a of the injection parts 12 and 22 overlap each other so that they face each other, and the opening opposite the bottom of the injection groove 22a of the second sheet 20 is blocked by the inner surface 10a of the injection part 12 of the first sheet 10, forming an injection flow path 5 that connects the outside to the hollow portion between the main body 11 and the main body 21 (the condensate flow path 3 and the steam flow path 4). However, after the working fluid is injected into the hollow portion from the injection passage 5, the injection passage 5 is closed to form a sealed space 2, so that in the final form of the vapor chamber 1, the hollow portion is not connected to the outside. In this embodiment, the injection part 12 and the injection part 22 are provided at one end of a pair of ends in the longitudinal direction of the vapor chamber 1, but the present invention is not limited to this and may be provided at any other end, or may be provided in a plurality of parts. When a plurality of parts are provided, they may be provided at each of a pair of ends in the longitudinal direction of the vapor chamber 1, or may be provided at one end of the other pair of ends.

[0108] A working fluid is sealed in the sealed space 2 of the vapor chamber 1. The type of working fluid is not particularly limited, but working fluids used in ordinary vapor chambers, such as pure water, ethanol, methanol, acetone, and mixtures thereof, can be used.

[0109] As described above, in the vapor chamber 1, the condensate flow path 3 and the steam flow path 4 are composed of outer layer 10e, outer layer 20e, inner layer 10d, and inner layer 20d, and the inner surfaces of the condensate flow path 3 and the steam flow path 4 are composed of inner layer 10d and inner layer 20d.

[0110] On the other hand, in this embodiment, the outside of the vapor chamber 1 is formed by the outer layer 10e and the outer layer 20e, and its shape is not determined by the condensate flow path 3 and the vapor flow path 4 on the inside (in this embodiment, it is flat).

[0111] In this embodiment, the outer layer 10e and the outer layer 20e have a higher strength than the inner layer 10d and the inner layer 20d, and can suppress deformation or damage of the vapor chamber even if the vapor chamber is thinned while having the condensate flow path 3 and the vapor flow path 4. That is, deformation or damage of the vapor chamber can be suppressed even when a force is applied due to an external impact, expansion due to solidification of the working fluid by low-temperature freezing, and steam pressure during operation.

[0112] On the other hand, the inner layer 10d and the inner layer 20d can be made of a material that is chemically stable against the working fluid and has high thermal conductivity, so that the thermal resistance can be kept small. At the same time, the outer layer 10e and the outer layer 20e can improve the strength of the vapor chamber, so that the pattern formed in the inner layer 10d and the inner layer 20d through which the working fluid moves can be designed with an emphasis on thermal performance rather than strength improvement, which is also advantageous from the viewpoint of thermal performance.

[0113] The vapor chamber 1 of this embodiment is particularly effective when it is thin. From this viewpoint, the thickness of the vapor chamber 1 is 1 mm or less, more preferably 0.4 mm or less, and even more preferably 0.2 mm or less. By making the thickness 0.4 mm or less, in electronic devices in which the vapor chamber 1 is installed, the vapor chamber can often be installed inside the electronic device without processing (e.g., forming a groove, etc.) to form a space in which the vapor chamber is to be installed. And according to this embodiment, even such a thin vapor chamber has high strength and is resistant to deformation while maintaining thermal performance.

[0114] The vapor chamber as described above can be manufactured, for example, by the following steps. An explanatory diagram is shown in Fig. 22A to Fig. 22D. First, as shown in FIG. 22A, a sheet 10e' that will become the outer layer 10e of the first sheet 10 is prepared. Next, as shown in Fig. 22B, grooves to become liquid flow path grooves 14a, liquid flow path grooves 15a, steam flow path grooves 16, and steam flow path connecting grooves 17 are formed in this sheet 10e' by half etching. Half etching refers to etching only partway through the sheet without penetrating the sheet in the thickness direction.

[0115] Next, as shown in Fig. 22C, the surface of the sheet 10e' that has been half-etched is sputtered or plated with a material that will become the inner layer 10d to form the inner layer 10d. At this time, an intermediate layer may be formed by sputtering or plating in order to improve adhesion, before sputtering or plating with the material for the inner layer 10d. If the intermediate layer is formed by sputtering, examples of the intermediate layer include titanium, nickel, and nickel chrome, and if the intermediate layer is formed by plating, it is called strike plating.

[0116] The first sheet 10 can be produced by including the above steps. This makes it possible to minimize the amount of material removed by processing even when using a laminated material, and therefore to reduce material loss. In addition, since there is no need to etch materials in which different metals are layered, it is possible to suppress corrosion due to the battery effect during processing and deterioration of processing accuracy due to differences in etching rate. In addition, materials made by rolling multiple types of metals into a laminate tend to warp more when they are made thinner, but by manufacturing them as described above, this warping can be kept small, which is expected to improve yields in joining and transportation.

[0117] The second sheet 20 is also produced by the above steps, and after obtaining the first sheet 10 and the second sheet 20, the inner surface 10a (inner layer 10d) of the first sheet 10 and the inner surface 20a (inner layer 20d) of the second sheet 20 are stacked so as to face each other as shown in Fig. 22D, and are positioned and temporarily fixed using the holes 13a and 23a as positioning means. The method of temporary fixing is not particularly limited, but examples include resistance welding, ultrasonic welding, and adhesion using an adhesive. After the temporary fixing, diffusion bonding is performed to permanently bond the first sheet 10 and the second sheet 20. Here, the term "permanently bonded" is not limited to a strict meaning, but means that the bond between the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20 can be maintained to such an extent that the airtightness of the sealed space 2 can be maintained when the vapor chamber 1 is in operation.

[0118] In the above embodiment, the inner layer 10d and the inner layer 20d are formed by sputtering or plating, and then the first sheet 10 and the second sheet 20 are joined by diffusion bonding. However, the present invention is not limited to this. For example, the inner layer 10d and the inner layer 20d may be made of a brazing material, which is a brazing material, on the premise that the first sheet 10 and the second sheet 20 are joined by brazing. This makes it possible to simultaneously form and join the inner layer 10d and the inner layer 20d.

[0119] After the first sheet 10 and the second sheet 20 are joined together as described above, a vacuum is drawn through the formed injection flow path 5 to reduce the pressure in the hollow portion. Thereafter, the working fluid is injected through the injection flow path 5 (see FIG. 1) into the reduced pressure hollow portion, and the working fluid is placed in the hollow portion. Then, the injection flow path 5 is closed by utilizing laser melting or crimping for the injection portions 12 and 22 to form an enclosed space. This allows the working fluid to be stably held inside the enclosed space 2.

[0120] In the vapor chamber of this embodiment, the overlap between the internal liquid flow path portion 15 and the inner liquid flow path portion 25 functions as a support, which can prevent the sealed space from collapsing when joining and reducing pressure. In addition, the strength is increased by the outer layer 10e and the outer layer 20e, which can also prevent the collapse from occurring.

[0121] Although the above describes the manufacture of the vapor chamber by etching, the manufacturing method is not limited to this, and the vapor chamber can also be manufactured by pressing, cutting, laser processing, and processing with a 3D printer. For example, when manufacturing a vapor chamber using a 3D printer, it is not necessary to create the vapor chamber by joining multiple sheets, and it is possible to create a vapor chamber with no joints.

[0122] Next, the operation of the vapor chamber 1 will be described. Fig. 23 shows a schematic diagram of the vapor chamber 1 disposed inside a portable terminal 40, which is one form of electronic device. Here, the vapor chamber 1 is shown by a dotted line because it is disposed inside a housing 41 of the portable terminal 40. Such a portable terminal 40 is configured with a housing 41 that contains various electronic components and a display unit 42 that is exposed so that images can be seen to the outside through an opening of the housing 41. And, as one of these electronic components, an electronic component 30 to be cooled by the vapor chamber 1 is disposed inside the housing 41.

[0123] The vapor chamber 1 is installed in the housing of a portable terminal or the like, and is attached to an electronic component 30, which is an object to be cooled, such as a CPU. The electronic component is attached directly to the outer surface 10b or outer surface 20b of the vapor chamber 1, or via a highly thermally conductive adhesive, sheet, tape, or the like. There is no particular limitation on the position of the outer surface 10b or outer surface 20b at which the electronic component is attached, and it is appropriately set depending on the relationship with the arrangement of other components in the portable terminal or the like. In this embodiment, as shown by the dotted line in FIG. 1, the electronic component 30, which is a heat source to be cooled, is placed on the outer surface 10b of the first sheet 10, at the center of the main body 11 in the xy direction. Therefore, in FIG. 1, the electronic component 30 is in a blind spot and cannot be seen, so it is represented by a dotted line. In the vapor chamber 1 of this embodiment, the outer surface 10b and the outer surface 20b are formed by the outer layer 10e and the outer layer 20e, and the shape is not made to conform to the shape of the flow path on the inner surface side. Therefore, the shape of the outer surface 10b and the outer surface 20b can be formed from the viewpoint of increasing the adhesion to the electronic components and the housing with which they come into contact, and from this viewpoint, the thermal performance can be improved.

[0124] A diagram for explaining the flow of the working fluid is shown in Fig. 24. 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.

[0125] When the electronic components 30 generate heat, the heat is transferred by thermal conduction within the first sheet 10, and the condensate present in the sealed space 2 near the electronic components 30 receives the heat. The condensate absorbs the heat and evaporates, thereby cooling the electronic components 30.

[0126] The evaporated working fluid turns into steam and moves within the steam flow path 4 as shown by the solid straight arrow in Fig. 24. Since this flow occurs in a direction away from the electronic component 30, the steam moves in a direction away from the electronic component 30. The steam in the steam flow path 4 moves away from the electronic component 30, which is the heat source, to the outer periphery of the vapor chamber 1, which is at a relatively low temperature, and is cooled as it moves while heat is absorbed by the first sheet 10 and the second sheet 20. The first sheet 10 and the second sheet 20, which have absorbed heat from the steam, transfer the heat to the housing 41 of the electronic device 40 in contact with their outer surfaces 10b and 20b, and the heat is finally released into the outside air.

[0127] The working fluid that has lost heat while moving through the steam flow passage 4 is condensed and liquefied. This condensed liquid adheres to the wall surface of the steam flow passage 4. On the other hand, since steam is continuously flowing through the steam flow passage 4, the condensed liquid adheres to the wall surface of the steam flow passage 4 as shown by the arrows I in Figs. 20 and 21. 11 As shown in FIG. 8 and FIG. 14, the condensate moves to the condensate flow passage 3 as if being pushed by the steam. Since the condensate flow passage 3 in this embodiment is provided with the communication openings 14c and 15c, the condensate passes through the communication openings 14c and 15c and is distributed to the multiple condensate flow passages 3.

[0128] 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. 24 due to the capillary force of the condensate flow path and the pressure from the steam. At this time, the openings of the liquid flow channel 3, the liquid flow channel grooves 14a and 15a, are blocked by the second sheet 20, so that the four sides of the cross section become walls, enhancing the capillary force, thereby enabling the smooth movement of the condensate. Then, the heat from the electronic component 30, which is the heat source, causes the vaporization again, and the above process is repeated.

[0129] The vapor chamber 1 described above is an example that is made up of two sheets, the first sheet 10 and the second sheet 20. However, this is not limited to this, and the vapor chamber may be made up of three sheets as shown in Fig. 25, or four sheets as shown in Fig. 26.

[0130] 25 is a laminate of a first sheet 10, a second sheet 20, and an intermediate third sheet 50. The third sheet 50 is disposed so as to be sandwiched between the first sheet 10 and the second sheet 20, which are joined to each other.

[0131] In this example, both the inner surface 10a and the outer surface 10b of the first sheet 10 are flat. Similarly, both the inner surface 20a and the outer surface 20b of the second sheet 20 are flat. The inner surfaces 10a and 20a are respectively composed of inner layers 10d and 20d, and the outer surfaces 10b and 20b are respectively composed of outer layers 10e and 20e. In this case, 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. This thickness range may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, this thickness range may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values.

[0132] On the other hand, the third sheet 50 is provided with a vapor flow passage groove 51, a wall 52, a liquid flow passage groove 53, and a protrusion 54. The steam flow path groove 51 is a groove that penetrates the third sheet 50 in the thickness direction, and is a groove similar to the steam flow path groove 16 and the steam flow path groove 26 described above that are overlapped to form the steam flow path 4, which is the first flow path, and has a shape corresponding thereto. The wall 52 is a wall provided between adjacent steam flow path grooves 51, and has a form corresponding to the wall in which the above-mentioned outer circumferential liquid flow path section 14 and outer circumferential liquid flow path section 24, and the inner liquid flow path section 15 and inner liquid flow path section 25 are overlapped. The liquid flow path groove 53 is a groove disposed on the surface of the wall 52 facing the first sheet 10, and has a shape corresponding to the above-mentioned liquid flow path groove 14a and liquid flow path groove 15a. The liquid flow path groove 53 forms a condensate flow path 3, which is a second flow path. The convex portion 54 is a convex portion disposed between adjacent liquid flow path grooves 53, and is disposed in a form corresponding to the above-mentioned convex portion 14b and convex portion 15b.

[0133] The third sheet 50 has grooves that serve as the condensate flow paths 3 and the steam flow paths 4, and the inner layer 50d is laminated inside the grooves. Since the third sheet 50 does not form an outer surface, the portion on which the inner layer 50d is laminated is the base layer 50f, which is a layer that serves as a base for laminating the inner layer 50d. Therefore, the wall 52 has the inner layer 50d laminated on the outer periphery of the base layer 50f. The material constituting the base layer 50f can be considered to be the same as that of the outer layer 10e.

[0134] The vapor chamber having the above-mentioned structure also has the same effect as that described above.

[0135] 26 is a laminate of a first sheet 10, a second sheet 20, and two intermediate sheets, a third sheet 60 and a fourth sheet 70. These sheets are laminated and joined in the order of the first sheet 10, the third sheet 60, the fourth sheet 70, and the second sheet 20.

[0136] In this embodiment, the first sheet 10 and the second sheet 20 have flat inner surfaces 10a, 20a and flat outer surfaces 10b, 20b. The inner surfaces 10a, 20a are formed of inner layers 10d, 20d, respectively, and the outer surfaces 10b, 20b are formed of outer layers 10e, 20e, respectively. In this case, 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 determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. The thickness range may also be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. In this embodiment, for ease of viewing, hatching of inner layers is omitted.

[0137] The third sheet 60 is provided with a liquid flow passage groove 14a, a liquid flow passage groove 15a, and a vapor flow passage groove 16. In this embodiment, the liquid flow path groove 14a, the liquid flow path groove 15a, and the steam flow path groove 16 are grooves that penetrate the third sheet 60 in the thickness direction, but apart from that, they can be of the same form as the liquid flow path groove 14a, the liquid flow path groove 15a, and the steam flow path groove 16 described above. The third sheet 60 has grooves formed therein that serve as the condensate flow paths 3 and the steam flow paths 4, and an inner layer 60d is laminated inside the grooves. Since the third sheet 60 does not form an outer surface, the portion on which the inner layer 60d is laminated serves as a base layer 60f that serves as a base for laminating the inner layer 60d. The material constituting the base layer 60f can be considered to be the same as that of the outer layer 10e.

[0138] The fourth sheet 70 is provided with steam flow grooves 26 . The steam flow passage groove 26 in this embodiment is a groove penetrating the fourth sheet 70 in the thickness direction, but apart from that, it can have the same form as the steam flow passage groove 26 described above. The fourth sheet 70 has a groove formed therein to serve as the steam flow path 4, and an inner layer 70d is laminated inside the groove. Since the fourth sheet 70 does not form an outer surface, the portion on which the inner layer 70d is laminated serves as a base layer 70f that serves as a base for laminating the inner layer 60d. The material constituting the base layer 70f can be considered to be the same as that of the outer layer 10e.

[0139] By stacking such sheets, a condensate flow path 3, which is a second flow path surrounded by the first sheet 10, the condensate flow path 14a, and the fourth sheet 70, and a condensate flow path 3, which is a second flow path surrounded by the first sheet 10, the condensate flow path 15a, and the fourth sheet 70 are formed. Similarly, the steam flow passage groove 16 and the steam flow passage groove 26 overlap each other and are disposed between the first sheet 10 and the second sheet 20 to form the steam flow passage 4, which is the first flow passage. The vapor chamber having the above-mentioned structure also has the same effect as that described above.

[0140] [Second Form] FIG. 27 is an external perspective view of the vapor chamber 101 according to the second embodiment, and FIG. 28 is an exploded perspective view of the vapor chamber 101. As shown in FIG. 27 and 28, the vapor chamber 101 of this embodiment has a first sheet 110 and a second sheet 120. As will be described later, the first sheet 110 and the second sheet 120 are stacked and joined (by diffusion bonding, brazing, or the like) to form a hollow space between the first sheet 110 and the second sheet 120, and the working fluid is sealed in this hollow space to form the sealed space 102 (see, for example, FIG. 45).

[0141] In this embodiment, the first sheet 110 is a sheet-like member as a whole, and is L-shaped in a plan view. Fig. 29 shows a perspective view of the first sheet 110 as seen from the inner surface 110a side, and Fig. 30 shows a plan view of the first sheet 110 as seen from the inner surface 110a side. Fig. 31 shows the I in Fig. 30. 101 -I 101 1 shows a cut surface of the first sheet 110 when cut at . The first sheet 110 has an inner surface 110a, an outer surface 110b opposite to the inner surface 110a, and a side surface 110c that spans the inner surface 110a and the outer surface 110b to form a thickness, and a pattern for a flow path through which the working fluid moves is formed on the inner surface 110a side. As described below, the inner surface 110a of the first sheet 110 and the inner surface 120a of the second sheet 120 are overlapped so as to face each other to form a hollow portion, and the working fluid is sealed in this to form the sealed space 102.

[0142] The thickness of the first sheet 110 is not particularly limited, but can be considered to be the same as that of the first sheet 10 described above.

[0143] The first sheet 110 includes a main body 111 and an injection portion 112. The main body 111 is in the form of a sheet that forms a portion through which the working fluid moves, and in this embodiment, is L-shaped having a curved portion in a plan view. Injection portion 112 is a portion where working fluid is injected into the hollow portion formed by first sheet 110 and second sheet 120, and in this embodiment, is a sheet-like shape that is rectangular in plan view and protrudes from the L-shaped main body 111 in plan view. In this embodiment, injection portion 112 of first sheet 110 has flat surfaces on both the inner surface 110a side and the outer surface 110b side.

[0144] A structure for moving the working fluid is formed on the inner surface 110a side of the main body 111. Specifically, the structure includes an outer periphery joining portion 113, an outer periphery liquid flow path portion 114, an inner liquid flow path portion 115, a steam flow path groove 116, and a steam flow path connecting groove 117 on the inner surface 110a side of the main body 111.

[0145] The outer periphery bonding portion 113 is a surface formed on the inner surface 110a side of the main body 111 along the outer periphery of the main body 111. This outer periphery bonding portion 113 overlaps and is bonded (diffusion bonding, brazing, etc.) to the outer periphery bonding portion 123 of the second sheet 120 to form a hollow portion between the first sheet 110 and the second sheet 120, and a working fluid is sealed in this hollow portion to form the sealed space 102. The width of the outer periphery bonding portion 113 can be appropriately set as needed, but can be considered to be the same as the width W1 described for the first sheet 10 at its narrowest portion.

[0146] The outer circumferential liquid flow path portion 114 functions as a liquid flow path portion, and is a portion that constitutes a part of the condensed liquid flow path 103 (see, for example, FIG. 46), which is a flow path through which the working fluid passes when it is condensed and liquefied. 102 The part shown in Fig. 33 is I 103 -I 103 In each of the drawings, the cross-sectional shape of the outer peripheral liquid flow path portion 114 is shown. 105 1 shows an enlarged plan view of the outer circumferential liquid flow path section 114 as viewed from the direction indicated by the arrow.

[0147] As can be seen from these figures, the peripheral liquid flow path section 114 is formed along the inside of the peripheral joint section 113 on the inner surface 110a of the main body 111, and is provided in a ring shape along the outer periphery of the sealed space 102. The peripheral liquid flow path section 114 is also formed with liquid flow path grooves 114a that are multiple grooves extending parallel to the direction in which the peripheral liquid flow path section 114 extends, and the multiple liquid flow path grooves 114a are arranged at intervals in a direction different from the direction in which the liquid flow path grooves 114a extend. Therefore, as can be seen from Figures 32 and 33, in the cross section of the peripheral liquid flow path section 114, the liquid flow path grooves 114a that are recesses and the walls 114b that are protrusions between the liquid flow path grooves 114a are formed in a repeated uneven shape. Here, since the liquid flow path groove 114a is a groove, its cross-sectional shape has a bottom and an opening on the opposite side facing the bottom.

[0148] By providing a plurality of liquid flow path grooves 114a in this manner, the depth and width of each liquid flow path groove 114a can be reduced, and the flow path cross-sectional area of ​​the condensate flow path 103 (see FIG. 46, for example) can be reduced, making it possible to utilize a large capillary force. On the other hand, by providing a plurality of liquid flow path grooves 114a, the total internal volume of the condensate flow path 103 as a whole can be ensured to be an appropriate size, and the condensate can flow at a required flow rate.

[0149] Furthermore, in the outer peripheral liquid flow passage portion 114, as can be seen from FIG. 23, adjacent liquid flow passage grooves 114a are communicated with each other through communication openings 114c provided at intervals in the wall 114b. This promotes equalization of the amount of condensed liquid among the plurality of liquid flow passage grooves 114a, and allows the condensed liquid to flow efficiently. In addition, the communication openings 114c provided in the wall 114b adjacent to the steam flow passage groove 116 forming the steam flow passage 104 communicate the steam flow passage 104 with the condensed liquid flow passage 103. Therefore, by providing the communication openings 114c, the condensed liquid generated in the steam flow passage 104 can be smoothly moved to the condensed liquid flow passage 103, and the steam generated in the condensed liquid flow passage 103 can also be smoothly moved to the steam flow passage 104, which also promotes smooth movement of the working fluid.

[0150] In this embodiment, as shown in Fig. 34, the communication openings 114c are arranged so as to face each other at the same position in the extension direction of one liquid flow path groove 114a, sandwiching the groove. However, this is not limited to this, and the communication openings 114c may be arranged following the example described using Fig. 9.

[0151] The width of the outer circumferential liquid flow path portion 114 can be considered to be the same as the width W2 described for the first sheet 10. The liquid flow path groove 114a can be considered to have the same groove width as the width W3 described for the first sheet 10, and the same groove depth as the depth D1 described for the first sheet 10. However, it is preferable that the depth of the liquid flow path groove 114a is smaller than the remaining sheet thickness obtained by subtracting the depth of the groove from the thickness of the first sheet 110. This makes it possible to more reliably prevent the sheet from breaking when the working fluid freezes. Regarding the wall 114b, W 101 The width indicated by is preferably 20 μm or more and 300 μm or less. If the width is less than 20 μm, the working fluid is easily broken due to repeated freezing and melting, and if the width is more than 300 μm, the width of the communication opening 114c becomes too large, which may hinder smooth communication of the working fluid with the adjacent condensate flow passage 103.

[0152] Regarding the communicating opening 114c, the size of the communicating opening 114c along the extension direction of the liquid flow path groove 114a can be considered to be the size L1 described for the first sheet 10, and the pitch between adjacent communicating openings 114c in the extension direction of the liquid flow path groove 114a can be considered to be the same as the pitch L2 described for the first sheet 10.

[0153] In this embodiment, the cross-sectional shape of the liquid flow path groove 114a is semi-elliptical, but is not limited to this and may be a square, rectangle, trapezoid or other quadrangle, triangle, semicircle, a semicircle with a bottom, a semi-ellipse with a bottom, or the like.

[0154] Moreover, it is preferable that the liquid flow passage groove 114a is formed continuously along the edge of the sealed space. In other words, it is preferable that the liquid flow passage groove 114a extends in an annular shape over the entire circumference without being interrupted by other components. This reduces factors that hinder the movement of the condensed liquid, allowing the condensed liquid to move smoothly.

[0155] In this embodiment, the peripheral liquid flow path section 114 is provided, but it is not essential that the peripheral liquid flow path section 114 is provided, and the peripheral liquid flow path section 114 may not be provided in consideration of the shape of the vapor chamber, the relationship with the device to which the vapor chamber is applied, the usage environment, etc. In this embodiment, the peripheral part of the sealed space can be configured as a vapor flow path to transport heat by vapor to the peripheral part of the vapor chamber, which may result in higher heat uniformity.

[0156] Returning to Fig. 29 to Fig. 31, the inner liquid flow path section 115 will be described. The inner liquid flow path section 115 also functions as a liquid flow path section, and is a part that constitutes a part of the condensed liquid flow path 103 through which the working fluid passes when it is condensed and liquefied. 105 The cross-sectional shape of the inner liquid flow path portion 115 is also shown in FIG. 36. Also, FIG. 36 shows the portion indicated by the arrow I in FIG. 106 1 shows an enlarged plan view of the inner liquid flow path section 115 as viewed from the direction indicated by the arrow.

[0157] As can be seen from these figures, the inner liquid flow path section 115 is formed inside the ring of the annular outer peripheral liquid flow path section 114 (or the outer peripheral joint section 113) on the inner surface 110a of the main body 111. As can be seen from Figures 29 and 30, the inner liquid flow path section 115 in this embodiment is a convex ridge extending with a curved section, and is arranged at intervals in a direction different from the extension direction of the multiple (five in this embodiment) inner liquid flow path sections 115, and is disposed between the steam flow path grooves 116. In each inner liquid flow path section 115, liquid flow path grooves 115a that are grooves parallel to the direction in which the inner liquid flow path section 115 extends are formed, and a plurality of liquid flow path grooves 115a are arranged at predetermined intervals in a direction different from the direction in which the liquid flow path grooves 115a extend. Therefore, as can be seen from Figures 31 and 36, in the cross section of the inner liquid flow path section 115, the liquid flow path grooves 115a that are recesses and the walls 115b that are protrusions between the liquid flow path grooves 115a are formed in a repeated pattern of recesses and projections. Here, since the liquid flow path groove 115a is a groove, its cross-sectional shape has a bottom and an opening on the opposite side facing the bottom.

[0158] By providing a plurality of liquid flow path grooves 115a in this way, the depth and width of each liquid flow path groove 115a can be reduced, and the flow path cross-sectional area of ​​the condensate flow path 103 (see FIG. 46, for example) can be reduced, making it possible to utilize a large capillary force. On the other hand, by providing a plurality of liquid flow path grooves 115a, the total internal volume of the condensate flow path 103 as a whole can be ensured to be an appropriate size, and the condensate can flow at a required flow rate.

[0159] Furthermore, in the inner liquid flow passage section 115, as can be seen from FIG. 36, the adjacent liquid flow passage grooves 115a are connected to each other by the communication openings 115c provided at intervals in the wall 115b in the same manner as in FIG. 34 following the example of the outer circumferential liquid flow passage section 114. This promotes equalization of the amount of condensed liquid among the plurality of liquid flow passage grooves 115a, and allows the condensed liquid to flow efficiently. In addition, the communication openings 115c provided in the wall 115b adjacent to the steam flow passage groove 116 forming the steam flow passage 104 communicate the steam flow passage 104 and the condensed liquid flow passage 103. Therefore, by configuring the communication openings 115c as described later, the condensed liquid generated in the steam flow passage 104 can be smoothly moved to the condensed liquid flow passage 103, and the steam generated in the condensed liquid flow passage can be smoothly moved to the steam flow passage 104, which also promotes the smooth movement of the working fluid.

[0160] Similarly, in the inner liquid flow path section 115, similar to the example in FIG. 9, the communication openings 115c may be disposed at different positions in the extension direction of one liquid flow path groove 115a, sandwiching the groove.

[0161] The width of the inner liquid flow path section 115 having the above-mentioned configuration can be considered to be the same as the width W4 described for the first sheet 10.

[0162] The liquid flow path groove 115a can be considered to have the same groove width as W5 and the same groove depth as D2 described for the first sheet 10. The groove depth is preferably smaller than the remaining sheet thickness obtained by subtracting the groove depth from the thickness of the first sheet 110. This makes it possible to more reliably prevent the sheet from breaking when the working fluid freezes.

[0163] Regarding the wall 115b, W is shown in FIG. 102 It is preferable that the width indicated by is 20 μm or more and 300 μm or less. If the width is smaller than 20 μm, the openings 115c are easily broken due to repeated freezing and melting of the working fluid, and if the width is larger than 300 μm, the width of the communication openings 115c becomes too large, which may hinder smooth communication between the condensate flow paths 103.

[0164] Regarding the communicating opening 115c, the size of the communicating opening 115c along the extension direction of the liquid flow path groove 115a can be considered to be the same as L3 described for the first sheet 10, and the pitch between adjacent communicating openings 115c in the extension direction of the liquid flow path groove 115a can be considered to be the same as L4 described for the first sheet 10.

[0165] In addition, in this embodiment, the cross-sectional shape of the liquid flow path groove 115a is semi-elliptical, but is not limited to this, and may be quadrangular such as square, rectangle, or trapezoid, triangular, semicircular, or having a semicircular bottom or a semi-elliptical bottom.

[0166] Next, the steam flow path groove 116 will be described. The steam flow path groove 116 is a portion through which the working fluid in a vapor state and a condensed liquid state moves, and constitutes a part of the steam flow path 104. Fig. 30 shows the shape of the steam flow path groove 116 in a plan view, and Fig. 31 shows the cross-sectional shape of the steam flow path groove 116.

[0167] As can be seen from these figures, the steam flow path groove 116 is formed as a groove formed on the inner surface 110a of the main body 111 inside the ring of the annular outer peripheral liquid flow path section 114. More specifically, the steam flow path groove 116 in this embodiment is formed between adjacent inner liquid flow path sections 115 and between the outer peripheral liquid flow path section 114 and the inner liquid flow path section 115, and is a groove that extends with curved portions. A plurality of steam flow path grooves 116 (six in this embodiment) are arranged in a direction different from the extending direction. Therefore, as can be seen from FIG. 31, the first sheet 110 has a shape in which projections and recesses are repeated, with the inner liquid flow path section 115 as protruding stripes and the steam flow path grooves 116 as recessed stripes. Here, since the steam flow passage groove 116 is a groove, its cross-sectional shape has a bottom and an opening located on the opposite side facing the bottom.

[0168] The vapor flow passage grooves 116 may be configured such that when the vapor flow passages 104 are formed in combination with the vapor flow passage grooves 126 of the second sheet 120, the working fluid moves through the vapor flow passages 104. The width of the vapor flow passage groove 116 is formed to be at least larger than the widths of the liquid flow passage grooves 114a and 115a described above, and can be considered to be the same as the width W6 described for the first sheet 10. On the other hand, the depth of the vapor flow passage groove 116 is formed to be at least greater than the depths of the liquid flow passage grooves 114a and 115a described above, and can be considered to be the same as the depth D3 described for the first sheet 10. As a result, when the steam flow path is formed, stable movement of the working fluid is achieved, and by making the flow path cross-sectional area of ​​the steam flow path groove larger than that of the liquid flow path groove, steam, which has a larger volume than condensed liquid due to the nature of the working fluid, can be moved smoothly.

[0169] Here, the steam flow channel groove 116 is preferably configured so that when combined with the second sheet 120 to form the steam flow channel 104 as described later, the steam flow channel 104 has a flat shape in which the width is greater than the height (size in the thickness direction). Therefore, the aspect ratio, which is the value obtained by dividing the height by the width, is preferably 4.0 or more, and more preferably 8.0 or more.

[0170] In this embodiment, the cross-sectional shape of the steam flow channel groove 116 is semi-elliptical, but is not limited to this and may be a square, rectangle, trapezoid or other quadrangle, triangle, semicircle, a circle with a bottom, a semi-ellipse with a bottom, or the like.

[0171] The steam flow passage communication groove 117 is a groove that connects the multiple steam flow passage grooves 116 and forms a flow passage that connects the multiple steam flow passages 104 formed by the steam flow passage grooves 116 at their ends in combination with the steam flow passage communication groove 127 of the second sheet 120. This allows smooth movement of the working fluid generated in the steam flow passage 104 in the direction in which the inner liquid flow passage section 115 extends. The steam flow passage communicating groove 117 can be considered to be similar to the steam flow passage communicating groove 17 described in the first sheet 10 .

[0172] In this embodiment, the first sheet 110 has a curved portion 118c which is a portion where the extension direction of the liquid flow path groove 114a (outer peripheral liquid flow path section 114), the liquid flow path groove 115a (inner liquid flow path section 115), and the vapor flow path groove 116 changes. That is, the first sheet 110 is provided with a straight portion 118a where the liquid flow path groove 114a (outer peripheral liquid flow path section 114), the liquid flow path groove 115a (inner liquid flow path section 115), and the steam flow path groove 116 extend linearly in the x direction, a straight portion 118b where the liquid flow path groove 114a (outer peripheral liquid flow path section 114), the liquid flow path groove 115a (inner liquid flow path section 115), and the steam flow path groove 116 extend linearly in the y direction, and a curved portion 118c that connects the liquid flow path groove 114a (outer peripheral liquid flow path section 114), the liquid flow path groove 115a (inner liquid flow path section 115), and the steam flow path groove 116 in the straight portion 118a and the straight portion 118b. Therefore, one end of the curved portion 118c is connected to one straight portion 118a and the other end is connected to the other straight portion 118b, and the liquid flow path groove 114a (outer peripheral liquid flow path portion 114), the liquid flow path groove 115a (inner liquid flow path portion 115), and the steam flow path groove 116 are curved so that the flow changes direction from the x direction to the y direction and from the y direction to the x direction. Here, the boundary between the straight portion and the curved portion may be defined as the point where the flow direction starts to change in each groove.

[0173] In this embodiment, in the curved portion 118c, the width of the plurality of steam flow path grooves 116 is configured to be larger on the inside where the radius of curvature is smaller and smaller on the outside where the radius of curvature is larger. This improves the balance of flow resistance in the curved portion, making the movement of the working fluid smoother and improving the heat transport capacity. The specific form for this purpose is not particularly limited, but examples include the forms shown in Figs. 37, 38, 39, and 40.

[0174] 37 to 40 are explanatory views focusing on one steam flow path groove 116. The meanings of the symbols in these figures are as follows. The steam flow groove 116 is formed on the inner wall of the curved portion 118c. in is the radius of curvature r inand its center is a circular arc of O1. The steam flow groove 116 is formed on the outer wall of the curved portion 118c. out is the radius of curvature r out and as will be explained later, the center of the arc is O1, O2, O3 or O4 depending on the shape. The narrowest steam flow groove 116 among the multiple steam flow grooves 116 belonging to the curved portion 118c has a width α, while the widths of the other steam flow grooves 116 are increased to β (α<β). That is, in this embodiment, the steam flow groove 116 located on the outermost side among the multiple steam flow paths 116 belonging to the curved portion 118c has a width α. The curve shown by the dotted line is a virtual line when the width of the steam flow passage groove 116 is α, and the radius of curvature in this case is r c and its center is a circular arc of O1. The radius of the curvature can be determined by considering a circle passing through three points in total: two points where the direction of the walls (inner wall, outer wall) in the curved portion starts to change, and one point in the middle of these two points. When the curvature is considered to be a part of a circle or an ellipse, as shown in Figs. 37 to 40, the circle is the "inside" of the curved portion, the center side of the ellipse (i.e., the O1, O2, O3, and O4 side) is the "inside" of the curved portion, and the opposite side of the circle and the center side of the ellipse is the "outside" of the curve. The shape of the curve is not limited to a shape like a part of a perfect circle, and may be a shape like a part of an ellipse, or a shape in which some of the multiple steam flow grooves arranged in the curved portion are straight lines. The shapes of the curved portions below can be considered in the same way.

[0175] In the example of FIG. 37, the outer wall w of the steam flow channel 116 at the curved portion 118c is out Radius of curvature r out is the radius of curvature r c is greater than (r out >r c ), and the center is O1. In this embodiment, the steam flow grooves 116 belonging to the curved portion 118c have a larger r out As a result, the groove width β of the steam flow passage groove 116 disposed on the inner side becomes larger.

[0176] In the example of FIG. 38, the outer wall w of the steam flow channel 116 at the curved portion 118c is out Radius of curvature r out is the radius of curvature r c Same as (r out =r c ), but its center is at O2, which is shifted toward the steam flow groove 116 side from O1. In this embodiment, in the steam flow groove 116 belonging to the curved portion 118c, the outer wall w out The center (O2) of the steam flow groove 116 may be made closer to the steam flow groove 116. This allows the groove width β to be larger for the steam flow groove 116 disposed closer to the inside.

[0177] In the example of FIG. 39, the outer wall w of the steam flow channel 116 at the curved portion 118c is out Radius of curvature r out is the radius of curvature r in and radius of curvature r c Smaller than (r out <r in <r c ), and its center is at O3 which is shifted from O1 toward the steam flow passage groove 116 side. In this embodiment, in the steam flow passage groove 116 belonging to the curved portion 118c, out The width β of the steam flow passage groove 116 disposed closer to the inside may be increased by both the size of O3 and the position of O3.

[0178] In the example of FIG. 40, the outer wall w of the steam flow channel 116 at the curved portion 118c is out Radius of curvature r out and the inner wall w in Radius of curvature r in and the r out The center O4 of in In this embodiment, the width β of the steam flow groove 116 belonging to the curved portion 118c may be set to be larger for the steam flow groove 116 located closer to the inside due to the position of O4.

[0179] In the examples of Figures 37 and 38, the outer wall wout In the embodiment, the straight line portion and the arc portion are connected by a single bent portion. However, the present invention is not limited to this, and the single bent portion may be configured to be multiple small bent portions or a curved portion, so that the direction of the portion changes gradually and smoothly.

[0180] There is no particular restriction on the degree to which the width of the inner steam flow groove is wider, but it is preferable that the width is about 3% to 20% wider than the adjacent groove arranged on the outside. This ratio does not need to be constant or regular among multiple grooves, and can be set appropriately.

[0181] The width of the steam flow path groove 116 in the curved portion 118c relative to the width of the steam flow path groove 116 in the straight portion 118b is not particularly limited, but the width may be made larger in a range of 10% to 100% compared to the straight portion 118a and the straight portion 118b. By setting the width in this range, it is possible to improve the balance between the flow resistance of the straight portion 118b and the flow resistance of the curved portion 118c.

[0182] In addition, although the above describes the configuration focusing on the width of the steam flow path groove, instead of or in addition to this, the depth of the steam flow path groove 116 in the curved portion 118c may be changed. That is, among the multiple steam flow path grooves 116 belonging to the curved portion 118c, the steam flow path groove 116 arranged on the outside may be the shallowest, and the steam flow path groove 116 arranged on the inside may be deeper. In a configuration in which the depth direction (z direction) is changed, the expansion in the planar direction (xy direction) is suppressed, so that it is possible to secure many areas for arranging the condensate flow path and improve the heat transport capacity, or to widen the outer periphery joint and improve the reliability of the pressure resistance.

[0183] That is, by configuring the widths of the steam flow passage grooves 116 in the curved portion 118c to be different for each groove as described above, the width of the steam flow passage arranged on the inside can be made larger than the width of the steam flow passage arranged on the outside in the curved portion when the first sheet 110 and the second sheet 120 are combined. This allows the flow passage cross-sectional area of ​​the steam flow passage arranged on the inside to be larger than the flow passage cross-sectional area of ​​the steam flow passage arranged on the outside in the curved portion. On the other hand, by configuring the depth of the steam flow channel grooves 116 in the curved portion 118c to be different for each groove, the height of the steam flow channel arranged on the inside can be made larger than the height of the steam flow channel arranged on the outside in the curved portion when the first sheet 110 and the second sheet 120 are combined. This allows the flow channel cross-sectional area of ​​the steam flow channel arranged on the inside to be larger than the flow channel cross-sectional area of ​​the steam flow channel arranged on the outside in the curved portion.

[0184] In addition, in the curved portion 118c, the communication openings 114c and 115c (see FIG. 34 and FIG. 36) provided in the walls 114b and 115b separating the liquid flow passage grooves 114a and 115a from the vapor flow passage groove 116 can be configured to have a pitch different from that of the other portions (the straight portion 118a and the straight portion 118b). In this case, the pitch of the communication openings in the curved portion may be larger or smaller than the pitch of the curved portions in the straight portion. The form to be adopted can be determined by comprehensively judging the form that can reduce the flow resistance, taking into consideration the effects of the overall shape of the vapor chamber, the position of the heat source, and the like. Alternatively, the curved portion 118c does not need to have the communication openings 114c and 115c provided in the walls 114b and 115b separating the liquid flow passage grooves 114a and 115a from the vapor flow passage groove 116.

[0185] In a configuration in which the pitch of the communication openings in the curved portion is made larger than the pitch of the communication openings in the straight portion, the working fluid flowing through the steam flow passage groove 116 (steam flow passage 104) can be prevented from entering the communication openings 114c and 115c at the curved portion 118c. At the curved portion 118c, a force acts on the working fluid moving through the steam flow passage groove 116 (steam flow passage 104) in the direction of flow such that the working fluid tries to flow directly into the communication openings 114c and 115c, so that the steam tends to enter the condensate flow passage 103 and the flow resistance tends to increase due to the unevenness of the communication openings 114c and 115c. In response to this, by increasing the pitch of the communicating openings 114c and 115c that contact the steam flow path groove 116 at the curved portion 118c, or by eliminating the communicating openings 114c and 115c that contact the steam flow path groove 116, it is possible to suppress such an increase in flow resistance, further reducing the difference in flow resistance for each steam flow path groove 116 (steam flow path 104), improving the balance of the movement of the working fluid, and increasing the heat transport capacity.

[0186] On the other hand, in a configuration in which the pitch of the communication openings in the curved portion is smaller than that of the straight portion, the steam flowing through the steam flow passage groove (steam flow passage) has more opportunities to strongly hit the wall surface in the curved portion, and therefore tends to condense easily. In this case, by making the pitch of the communication openings in the curved portion smaller than that of the straight portion, the number of communication openings can be increased, and the condensate can be smoothly introduced into the liquid flow passage groove (condensate flow passage), making it possible to prevent the steam flow passage from being blocked by the condensate. This can suppress an increase in flow resistance, further reduce the difference in flow resistance between the steam flow passage grooves (steam flow passages), improve the balance of the movement of the working fluid, and may increase the heat transport capacity.

[0187] Alternatively, instead of the pitch, the length of the wall between adjacent communication openings in the curved portion (the length in the direction along the flow path) may be greater or smaller than the length of the wall in the straight portion. In this case, the length of the walls in the curved portion does not need to be constant and may be different for each wall. In this case, the relationship between the length of the walls in the curved portion and the length of the walls in the straight portion is determined by the relationship between the average lengths of the walls in the respective portions.

[0188] Next, the second sheet 120 will be described. In this embodiment, the second sheet 120 is also a sheet-like member as a whole, and is curved in an L-shape in a plan view. Fig. 41 shows a perspective view of the second sheet 120 as seen from the inner surface 120a side, and Fig. 42 shows a plan view of the second sheet 120 as seen from the inner surface 120a side. Fig. 43 shows the I in Fig. 42. 107 -I 107 FIG. 44 shows a cut surface of the second sheet 120 when cut at I in FIG. 108 -I 108 1 shows a cut surface of the second sheet 120 when cut at . The second sheet 120 has an inner surface 120a, an outer surface 120b opposite to the inner surface 120a, and a side surface 120c that spans the inner surface 120a and the outer surface 120b to form a thickness, and a pattern is formed through which the working fluid moves on the inner surface 120a side. As described later, the inner surface 120a of the second sheet 120 and the inner surface 110a of the first sheet 110 are overlapped and joined so as to face each other to form a hollow portion, in which the working fluid is sealed to form the sealed space 102.

[0189] The thickness of the second sheet 120 is not particularly limited, but can be considered to be similar to that of the second sheet 20 described above.

[0190] The second sheet 120 includes a main body 121 and an injection portion 122. The main body 121 is in the form of a sheet that forms a portion through which the working fluid moves, and in this embodiment, is L-shaped having a curved portion in a plan view. Injection section 122 is a section where working fluid is injected into the hollow section formed by first sheet 110 and second sheet 120, and in this embodiment, is a sheet-like shape that is rectangular in plan view and protrudes from the L-shaped section of main body 121 in plan view. In this embodiment, injection section 122 of second sheet 120 has injection groove 122a formed on inner surface 120a side, and communicates from side surface 120c of second sheet 120 to the inside of main body 121 (the section that is to become the hollow section, sealed space 102).

[0191] A structure for moving the working fluid is formed on the inner surface 120a side of the main body 121. Specifically, the inner surface 120a side of the main body 121 is provided with an outer periphery joining portion 123, an outer periphery liquid flow path portion 124, an inner liquid flow path portion 125, a steam flow path groove 126, and a steam flow path connecting groove 127.

[0192] The outer periphery bonding portion 123 is a surface formed on the inner surface 120a side of the main body 121 along the outer periphery of the main body 121. This outer periphery bonding portion 123 overlaps and is bonded (by diffusion bonding, brazing, or the like) to the outer periphery bonding portion 113 of the first sheet 110, thereby forming a hollow portion between the first sheet 110 and the second sheet 120, and a working fluid is sealed in this hollow portion to form the sealed space 102. The width of the peripheral joint portion 123 is preferably the same as the width of the peripheral joint portion 113 of the main body 111 of the first sheet 110 described above.

[0193] The outer circumferential liquid flow path section 124 functions as a liquid flow path section, and is a portion that constitutes a part of the condensed liquid flow path 103 (see FIG. 46, for example), which is a flow path through which the working fluid passes when it is condensed and liquefied.

[0194] The peripheral liquid flow path section 124 is formed along the inside of the peripheral joint section 123 on the inner surface 120a of the main body 121, and is formed to form a ring shape along the outer periphery of the sealed space 102. In this embodiment, the peripheral liquid flow path section 124 of the second sheet 120 is a flat surface and is flush with the peripheral joint section 123 before being joined to the first sheet 110, as can be seen from Figures 43 and 44. This closes the openings of at least some of the liquid flow path grooves 114a of the first sheet 110 described above, thereby forming the condensate flow path 103. A detailed embodiment of the combination of the first sheet 110 and the second sheet 120 will be described later. In this way, since the outer peripheral bonding portion 123 and the outer peripheral liquid flow path portion 124 are flush with each other in the second sheet 120, there is no structural boundary line that distinguishes the two. However, for ease of understanding, the boundary between the two is indicated by a dotted line in Figures 41 and 42.

[0195] The width of the outer circumferential liquid flow path section 124 is not particularly limited, and may be the same as the width of the outer circumferential liquid flow path section 114 of the first sheet 110 or may be different. When the width of the peripheral liquid flow path section 124 is made smaller than the width of the peripheral liquid flow path section 113, in at least a part of the peripheral liquid flow path section 114, the opening of the liquid flow path groove 114a is not closed by the peripheral liquid flow path section 124 but is open, making it easier for condensed liquid to enter and steam to exit, thereby enabling smoother movement of the working fluid.

[0196] In this embodiment, the peripheral liquid flow path portion 124 of the second sheet 120 is configured to have a flat surface, but is not limited thereto, and liquid flow path grooves may be provided similarly to the peripheral liquid flow path portion 114. In this case, the liquid flow path grooves of the first sheet and the liquid flow path grooves of the second sheet are overlapped to form the condensate liquid flow path 103.

[0197] As explained in the first sheet in this embodiment, the peripheral liquid flow path portion 124 does not necessarily have to be provided, and the peripheral liquid flow path portion 124 may not be provided.

[0198] Next, a description will be given of the inner liquid flow path section 125. The inner liquid flow path section 125 is also a liquid flow path section, and is one of the parts that configure the condensed liquid flow path 103.

[0199] 41 to 44, the inner liquid flow path section 125 is formed on the inner surface 120a of the main body 121, inside the annular ring of the outer circumferential liquid flow path section 124. The inner liquid flow path section 125 in this embodiment is a convex ridge extending with a curved portion, and is arranged at intervals in a direction different from the direction in which the multiple (five in this embodiment) inner liquid flow path sections 125 extend, and is disposed between the steam flow path grooves 126. In this embodiment, each inner liquid flow path portion 125 is formed so that its surface on the inner surface 120a side is flat before being joined to the first sheet 110. As a result, the openings of at least some of the liquid flow path grooves 115a of the first sheet 110 described above are closed to form the condensed liquid flow paths 103. When no grooves for forming the condensate flow paths 103 are formed in the inner liquid flow path section 125 as in this embodiment, the thickness of the second sheet 120 is preferably equal to or greater than the thickness of the first sheet 110 minus the depth of the liquid flow path grooves 115a. This makes it possible to prevent breakage (tear) on the second sheet side in the vapor chamber.

[0200] In this embodiment, the inner liquid flow path section 125 of the second sheet 120 is configured to have a flat surface, but is not limited to this, and liquid flow path grooves may be provided similarly to the inner peripheral liquid flow path section 115. In this case, the liquid flow path grooves of the first sheet and the liquid flow path grooves of the second sheet are overlapped to form the condensed liquid flow paths 103.

[0201] The width of the inner liquid flow path section 125 is not particularly limited, and may be the same as or different from the width of the inner liquid flow path section 115 of the first sheet 110. In this embodiment, the width of the inner liquid flow path section 125 and the width of the inner liquid flow path section 115 are the same. The influence of misalignment during joining can be reduced by making the width of the inner liquid flow path section 125 different from the width of the inner liquid flow path section 115. When the width of the inner liquid flow path section 125 is made smaller than the width of the inner liquid flow path section 115, the openings of the liquid flow path grooves 115a in at least a part of the inner liquid flow path section 115 are not closed by the inner liquid flow path section 125 but are open, allowing condensed liquid to easily enter and generated steam to easily exit, thereby allowing the working fluid to move more smoothly.

[0202] Next, the steam flow path groove 126 will be described. The steam flow path groove 126 is a portion through which the working fluid in a vapor state and a condensed liquid state moves, and constitutes a part of the steam flow path 104. Fig. 42 shows the shape of the steam flow path groove 126 in a plan view, and Fig. 43 shows the cross-sectional shape of the steam flow path groove 126.

[0203] As can be seen from these figures, the steam flow path groove 126 is formed as a groove having a curved portion formed on the inner surface 120a of the main body 121 inside the ring of the annular outer peripheral liquid flow path section 124. More specifically, the steam flow path groove 126 in this embodiment is a groove formed between adjacent inner liquid flow path sections 125 and between the outer peripheral liquid flow path section 124 and the inner liquid flow path section 125. A plurality of steam flow path grooves 126 (six in this embodiment) are arranged in a direction different from the direction in which the steam flow path grooves 126 extend. Therefore, as can be seen from FIG. 43, the second sheet 120 has a shape in which a convex rib is formed with the inner liquid flow path section 125 as a convex, and a concave rib is formed with the steam flow path groove 126 as a concave, and these concaves and convexes are repeated. Here, since the steam flow passage groove 126 is a groove, its cross-sectional shape has a bottom and an opening located on the opposite side facing the bottom.

[0204] The steam flow path groove 126 is preferably disposed at a position where, when combined with the first sheet 110, it overlaps with the steam flow path groove 116 of the first sheet 110 in the thickness direction. In this way, the steam flow path groove 116 and the steam flow path groove 126 can form the steam flow path 104. The width of the steam flow passage groove 126 is not particularly limited, and may be the same as or different from the width of the steam flow passage groove 116 of the first sheet 110. In this embodiment, the width of the steam flow passage groove 116 and the width of the steam flow passage groove are the same. The influence of misalignment during joining can be reduced by making the width of the steam flow path groove 126 different from the width of the steam flow path groove 116. When the width of the steam flow path groove 126 is made larger than the width of the steam flow path groove 116, the opening of the liquid flow path groove 115a in at least a part of the inner liquid flow path section 115 is not closed by the inner liquid flow path section 125 but is open, allowing condensed liquid to easily enter and steam to easily exit, thereby enabling smoother movement of the working fluid. On the other hand, the depth of the steam flow passage groove 126 can be considered to be similar to that of the steam flow passage groove 26 of the second sheet 20 described above.

[0205] Here, the steam flow channel groove 126 is preferably configured so that when combined with the first sheet 110 to form the steam flow channel 104 as described later, the steam flow channel 104 has a flat shape in which the width is greater than the height (size in the thickness direction). Therefore, the aspect ratio, which is the value obtained by dividing the depth of the steam flow channel groove 126 by the width of the steam flow channel groove 126, is preferably 4.0 or more, and more preferably 8.0 or more.

[0206] In this embodiment, the cross-sectional shape of the steam flow channel groove 126 is semi-elliptical, but it may be quadrangular such as square, rectangle, or trapezoid, triangular, semicircular, or with a semicircular bottom or semi-elliptical bottom.

[0207] The steam flow passage communication groove 127 is a groove that, in combination with the steam flow passage communication groove 117 of the first sheet 110, forms a flow passage that communicates the ends of the multiple steam flow passages 104 formed by the steam flow passage groove 126. The steam flow passage communication groove 127 can be considered to be similar to the steam flow passage communication groove 27 of the second sheet 20 described above.

[0208] In this embodiment, the second sheet 120 has curved portions 128c which are portions where the extension directions of the outer circumferential liquid flow path portion 124, the inner liquid flow path portion 125, and the steam flow path groove 126 change. That is, as can be seen from Fig. 42, the second sheet 120 has straight portions 128a where the outer circumferential liquid flow path portion 124, the inner liquid flow path portion 125, and the steam flow path groove 126 extend linearly in the x direction, straight portions 128b where the outer circumferential liquid flow path portion 124, the inner liquid flow path portion 125, and the steam flow path groove 126 extend linearly in the y direction, and curved portions 128c which connect the outer circumferential liquid flow path portion 124, the inner liquid flow path portion 125, and the steam flow path groove 126 at the straight portions 128a and 128b. Therefore, one end of the curved portion 128c is connected to one straight portion 128a and the other end is connected to the other straight portion 128b, and the outer peripheral liquid flow path portion 124, the inner liquid flow path portion 125, and the steam flow path groove 126 are curved so that the flow changes direction from the x direction to the y direction and from the y direction to the x direction.

[0209] In the curved portion 128c of this embodiment, the configuration of the outer circumferential liquid flow path portion 124, the inner liquid flow path portion 125, and the steam flow path groove 126 can be considered to be similar to that of the curved portion 118c of the first sheet 110 described above.

[0210] Next, a description will be given of the structure when the first sheet 110 and the second sheet 120 are combined to form the vapor chamber 101. This description will provide a better understanding of the arrangement, size, shape, and the like of each component of the first sheet 110 and the second sheet 120. In Figure 45, I 109 -I 109 43 shows a cross section of vapor chamber 101 cut in the thickness direction along the y direction indicated by the arrows 44. This figure shows the cross section of vapor chamber 101 at this portion by combining the diagram of first sheet 110 shown in FIG. 31 and the diagram of second sheet 120 shown in FIG. 43. Figure 46 shows the I in Figure 45. 110 The figure shows an enlarged view of the area indicated by . In Figure 47, I 111 -I 11133 shows a cross section of vapor chamber 101 cut in the thickness direction along the x direction indicated by the arrows 34. This figure shows the cross section of vapor chamber 101 at this portion by combining the diagram of first sheet 110 shown in FIG. 33 and the diagram of second sheet 120 shown in FIG. 44.

[0211] 27, 28, and 45 to 47, the first sheet 110 and the second sheet 120 are arranged so as to overlap and are joined to form the vapor chamber 101. At this time, the inner surface 110a of the first sheet 110 and the inner surface 120a of the second sheet 120 are arranged so as to face each other, the main body 111 of the first sheet 110 and the main body 121 of the second sheet 120 overlap, and the injection portion 112 of the first sheet 110 and the injection portion 122 of the second sheet 120 overlap.

[0212] By laminating the first sheet 110 and the second sheet 120, the components provided in the main body 111 and the main body 121 are arranged as shown in Figures 45 to 47. Specifically, they are as follows.

[0213] The vapor chamber 101 of this embodiment is particularly effective when it is thin. 100 The thickness of vapor chamber 101 shown in is 1 mm or less, more preferably 0.4 mm or less, and even more preferably 0.2 mm or less. By making it 0.4 mm or less, in electronic devices in which vapor chamber 101 is installed, it is often possible to install the vapor chamber inside the electronic device without processing (e.g., forming a groove, etc.) to form a space in which the vapor chamber is to be installed. And according to this embodiment, even such a thin vapor chamber has high strength and is resistant to deformation while maintaining thermal performance.

[0214] On the other hand, the outer peripheral joining portion 113 of the first sheet 110 and the outer peripheral joining portion 123 of the second sheet 120 are arranged so as to overlap each other, and are joined together by a joining means such as diffusion bonding or brazing, and a working fluid is sealed in. As a result, an enclosed space 102 is formed between the first sheet 110 and the second sheet 120.

[0215] Additionally, the outer circumferential liquid flow path section 114 of the first sheet 110 and the outer circumferential liquid flow path section 124 of the second sheet 120 are arranged to overlap with each other. As a result, the liquid flow path grooves 114a of the outer circumferential liquid flow path section 114 and the outer circumferential liquid flow path section 124 form a condensed liquid flow path 103 through which the condensed liquid, which is the working fluid that has been condensed and liquefied, flows. Similarly, the inner liquid flow path section 115 which is a convex rib of the first sheet 110 and the inner liquid flow path section 125 which is a convex rib of the second sheet 120 are arranged to overlap each other. As a result, the liquid flow path grooves 115a of the inner liquid flow path section 115 and the inner liquid flow path section 125 form condensate liquid flow paths 103 through which the condensate flows.

[0216] Here, it is preferable that the cross-sectional shape of the condensate flow path 103 is flattened in accordance with the thinning of the vapor chamber 101. This can increase the capillary force and facilitate smooth movement of the condensate, so that the heat transport capacity can be maintained at a high level. More specifically, it is preferable that the aspect ratio of the condensate flow path 103, which is expressed by dividing the width by the height, is greater than 1.0 and equal to or less than 4.0. In this embodiment, the width of the condensate flow path 103 is equivalent to the width of the liquid flow path groove 115a, but is preferably 10 μm to 300 μm. If the width is less than 10 μm, the flow path resistance increases and the transport capacity may decrease. On the other hand, if the width is more than 300 μm, the capillary force decreases and the transport capacity may decrease. In addition, the height of the condensate flow path 103 is preferably 5 μm or more and 200 μm or less, which corresponds to the depth of the liquid flow path groove 115a in this embodiment. This allows the capillary force of the condensate flow path required for movement to be fully exerted. Note that this height is preferably less than the thickness (wall thickness) of the first sheet 110 and the second sheet 120 on one side and the other side in the thickness direction (z direction) across the condensate flow path 103. This further prevents the vapor chamber from breaking (rupturing) due to the condensate flow path 103.

[0217] The cross-sectional shape of the condensate flow path 103 is semi-elliptical due to the cross-sectional shapes of the liquid flow path grooves 114a and 115a, but is not limited thereto and may be a square, a rectangle, a trapezoid or other quadrangle, a triangle, a semicircle, a semicircle with a bottom, a semi-ellipse with a bottom, or a combination of these, etc. Also, it may be a crescent shape.

[0218] In this embodiment, liquid flow path grooves 114a and 115a are provided only in first sheet 110, so the height of the condensate flow path is based on the depth of liquid flow path grooves 114a and 115a, but this is not limiting and liquid flow path grooves may also be provided in second sheet 120. In this case, the liquid flow path grooves of the first sheet and the second sheet overlap each other to form a condensate flow path, and the height of the condensate flow path corresponds to the sum of the depths of both liquid flow path grooves.

[0219] In this way, when the first sheet and the second sheet are provided with liquid flow passage grooves and then overlapped to form a condensate flow passage, the condensate flow passage can be configured as shown in Figs. 48 to 50. The example of FIG. 48 is an example in which the liquid flow passage grooves of the first sheet and the second sheet have the same width and are disposed at the same positions. 49 is an example in which the width of the liquid flow path groove in the second sheet is made larger than that of the first sheet, and the positions of the grooves match. In this example, a protrusion is formed in the condensate flow path as shown by P, which improves the capillary force and increases the force that moves the condensate (the force that supplies the condensate). In the example of Fig. 51, the liquid flow channel grooves of the first sheet and the second sheet are the same width, but are arranged at offset positions. In this example as well, a protrusion is formed in the condensate flow channel as indicated by P, which improves the capillary force and increases the force with which the condensate moves (the force with which the condensate is supplied).

[0220] As described above, the condensate flow passage 103 is formed with the communication opening 114c and the communication opening 115c. This allows the multiple condensate flow passages 103 to communicate with each other, and the condensate is uniformly distributed, allowing efficient movement of the condensate. The communication openings 114c and 115c are adjacent to the steam flow passage 104 and communicate the steam flow passage 104 and the condensate flow passage 103, allowing the condensate generated in the steam flow passage 104 to move smoothly to the condensate flow passage 103, and the steam generated in the condensate flow passage 103 to move smoothly to the steam flow passage 104, allowing the working fluid to move quickly.

[0221] Moreover, the condensate flow path 103 formed by the peripheral liquid flow path section 114 and the peripheral liquid flow path section 124 is preferably formed in a continuous ring shape along the edge of the sealed space 102. That is, the condensate flow path 103 formed by the peripheral liquid flow path section 114 and the peripheral liquid flow path section 124 is preferably formed in a ring shape and extends around the circumference without being interrupted by other components. This can reduce factors that impede the movement of the condensate, allowing the condensate to move smoothly.

[0222] In this embodiment, as explained above, the condensate flow path is formed by providing a condensate flow path groove in the sheet, but instead, a means for generating capillary force may be separately disposed here to form the condensate flow path. For this purpose, for example, a so-called wick such as a mesh material, nonwoven fabric, stranded wire, or sintered metal powder may be disposed.

[0223] The opening of the steam flow passage groove 116 in the first sheet 110 and the opening of the steam flow passage groove 126 in the second sheet 120 overlap so as to face each other, forming a flow passage, which becomes the steam flow passage 104. Here, it is preferable that the cross-sectional shape of the vapor flow path 104 is flattened in accordance with the thinning of the vapor chamber 101. This makes it possible to secure the surface area within the flow path even when the vapor chamber 101 is thinned, and makes it possible to maintain a high level of heat transport capacity. More specifically, it is preferable that the aspect ratio, which is expressed by the value obtained by dividing the width of the vapor flow path 104 by the height of the vapor flow path 104, is 2.0 or more. From the viewpoint of securing an even higher heat transport capacity, it is even more preferable that the ratio is 4.0 or more.

[0224] As can be seen from Figure 47, the opening of steam flow path communication groove 117 of first sheet 110 and the opening of steam flow path communication groove 127 of second sheet 120 overlap to face each other, forming a flow path, which connects the ends of multiple steam flow paths 104 formed by steam flow path groove 116 and steam flow path groove 126, providing a flow path for balancing the movement of working fluid.

[0225] As described above, in the sealed space 102 of the vapor chamber 101, the condensate flow path 103 and the steam flow path 104 are formed by the shapes of the first sheet 110 and the second sheet 120. Fig. 51 shows a diagram focusing on the condensate flow path 103 and the steam flow path formed in the sealed space 102. As can be seen from Figures 46, 51, etc., the vapor chamber 101 has a shape in which a plurality of condensate flow paths 103 are arranged between two vapor flow paths 104. This results in a configuration in which the condensate flow path 103, through which the condensate should mainly flow, and the steam flow path 104, through which the steam and condensate move, are separated and alternately arranged, which helps smooth movement of the working fluid.

[0226] The working fluid in the form of vapor and condensate moves through the vapor flow path 104 and the condensate flow path 103, and heat is efficiently transferred and diffused. Meanwhile, the condensate moves efficiently through the condensate flow path 103, which is provided separately from the vapor flow path 104, by capillary force, and therefore it is possible to suppress the occurrence of dryout.

[0227] Moreover, in the vapor chamber 101, two straight sections 106 in which the condensate flow path 103 and the vapor flow path 104 extend in different directions are connected by a curved section 107. By forming such a flow path, even if the vapor chamber is placed in an electronic device and there are restrictions on its placement, and it is not possible to form a flow path that is only linear, the provision of curved section 107 makes it possible to efficiently transfer heat generated from the heat source to a remote position.

[0228] This curved portion 107 is formed by curved portion 118c of first sheet 110 and curved portion 128c of second sheet 120. Therefore, one end of curved portion 107 is connected to one straight portion 106, and the other end is connected to the other straight portion 106, and condensate flow path 103 and steam flow path 104 are curved so that the flow direction changes from the x direction to the y direction and from the y direction to the x direction.

[0229] In this embodiment, the cross-sectional area of ​​the steam flow passage 104 belonging to the curved portion 107 is configured so that the cross-sectional area of ​​the steam flow passage 104 arranged on the inside is larger than the cross-sectional area of ​​the steam flow passage 104 arranged on the outside. This can improve the balance of the flow resistance in the curved portion, making the movement of the working fluid smoother and improving the heat transport capacity. Specifically, the cross-sectional area of ​​the steam flow passage can be adjusted by adjusting at least one of the width and height of the flow passage. Here, the "cross-sectional area of ​​a flow channel" refers to the cross-sectional area of ​​the flow channel in a plane perpendicular to the direction in which the flow channel extends.

[0230] The means, degree, and concept of increasing the flow path cross-sectional area (width in this embodiment) of the steam flow path 104 in the curved portion 107 are similar to those explained for the curved portion 118c of the first sheet 110 described above.

[0231] In addition, in the curved portion 107, the communication openings 114c and 115c (see Figs. 34 and 36) provided in the walls 114b and 115b separating the condensate flow path 103 and the steam flow path 104 can be configured to have a pitch different from that of the straight portion 106. The pitch of the communication openings in the curved portion may be larger or smaller than the pitch of the curved portions in the straight portion. The type of the curved portion 107 can be determined by comprehensively determining the type that can reduce the flow resistance, taking into account the effects of the overall shape of the vapor chamber, the position of the heat source, and the like. Alternatively, the curved portion 107 does not need to have the communication openings 114c and 115c in the walls 114b and 115b separating the condensate flow path 103 and the steam flow path 104. In a configuration in which the pitch of the communication openings in the curved portion is larger than the pitch of the communication openings in the straight portion, the working fluid flowing through the steam flow path 104 can be prevented from entering the communication openings 114c and 115c at the curved portion 107. In the curved portion 107, the working fluid moving through the steam flow path 104 is forced to flow directly into the communication openings 114c and 115c in the direction of its flow, so that the steam tends to enter the condensate flow path 103 and the flow resistance tends to increase due to the unevenness of the communication openings 114c and 115c. In response to this, by increasing the pitch of the communication openings 114c and 115c that contact the steam flow path 104 at the curved portion 107 or by eliminating the communication openings 114c and 115c that contact the steam flow path 104, it is possible to prevent such an increase in flow resistance, further reducing the difference in flow resistance for each steam flow path 104, improving the balance of the movement of the working fluid, and increasing the heat transport capacity. On the other hand, when the pitch of the communication openings in the curved section is smaller than that of the straight section, the steam flowing through the steam flow groove (steam flow path) has more opportunities to strongly hit the wall surface in the curved section, which tends to make it easier to condense. In this case, by making the pitch of the communication openings in the curved section smaller than that of the straight section, the number of communication openings can be increased, and the condensate can be smoothly introduced into the liquid flow groove (condensate flow path), making it possible to prevent the steam flow path from being blocked by the condensate. This can prevent an increase in flow resistance, further reduce the difference in flow resistance between the steam flow grooves (steam flow paths), improve the balance of the movement of the working fluid, and may increase the heat transport capacity.

[0232] Alternatively, instead of the pitch, the length of the wall between adjacent communication openings in the curved portion (the length in the direction along the flow path) may be greater or smaller than the length of the wall in the straight portion. In this case, the length of the walls in the curved portion does not need to be constant and may be different for each wall. In this case, the relationship between the length of the walls in the curved portion and the length of the walls in the straight portion is determined by the relationship between the average lengths of the walls in the respective portions.

[0233] On the other hand, as shown in Figures 27 and 28, the inner surfaces 110a, 120a of the injection parts 112 and 122 overlap each other so that they face each other, and the opening opposite the bottom of the injection groove 122a of the second sheet 120 is blocked by the inner surface 110a of the injection part 112 of the first sheet 110, and an injection flow path 105 is formed that connects the outside to the hollow portion between the main body 111 and the main body 121 (the condensate flow path 103 and the steam flow path 104). However, after the working fluid is injected from the injection passage 105 into the sealed space 102, the injection passage 105 is closed, so that in the final form of the vapor chamber 101, the sealed space 102 does not communicate with the outside.

[0234] A working fluid is sealed in the sealed space 102 of the vapor chamber 101. The type of working fluid is not particularly limited, but working fluids used in ordinary vapor chambers, such as pure water, ethanol, methanol, and acetone, can be used.

[0235] The vapor chamber 101 as described above can be fabricated in the same manner as the vapor chamber 1 described above.

[0236] Next, a description will be given of the operation of the vapor chamber 101. The manner in which the vapor chamber 101 is attached to an electronic device can be considered to be similar to the manner described with reference to FIG.

[0237] Fig. 52 is a diagram for explaining the behavior of the working fluid. For ease of explanation, this diagram is taken from the same perspective as Fig. 51, and focuses on the condensate flow path 103 and the steam flow path 104 formed in the sealed space 102. When the electronic component 30 generates heat, the heat is transferred by thermal conduction within the first sheet 110, and the condensate present in the sealed space 102 near the electronic component 30 receives the heat. The condensate absorbs the heat and evaporates, thereby cooling the electronic component 30.

[0238] The vaporized working fluid becomes vapor and moves through vapor flow path 104. The vaporized working fluid may move in a vibrating manner within vapor flow path 104 as shown by the solid straight arrow in Fig. 52, or may move in one direction away from electronic component 30, which is a heat source, without vibrating, although this is not shown. At this time, the steam flow path 104 includes a curved portion of the curved portion 107, but because the curved portion 107 has the above-mentioned configuration, the flow resistance is well balanced even in the curved portion 107, so the working fluid moves smoothly through the steam flow path 104. This makes it possible to exhibit high heat transport capacity. During this movement of the working fluid, the working fluid is cooled as heat is absorbed by first sheet 110 and second sheet 120. First sheet 110 and second sheet 120 absorb heat from the vapor and transfer the heat to the housing of the portable terminal device in contact with their outer surfaces 110b and 120b, and the heat is finally released to the outside air. Then, the working fluid absorbs heat while moving through vapor flow path 104 and is condensed and liquefied.

[0239] A portion of the condensate generated in the steam flow passage 104 moves from the communicating openings to the condensate flow passages 103. Since the condensate flow passages 103 in this embodiment are provided with the communicating openings 114c and 115c, the condensate is distributed to the multiple condensate flow passages 103 through the communicating openings 114c and 115c.

[0240] The condensate that has entered the condensate flow path 103 moves toward the heat source, electronic component 30, due to the capillary force of the condensate flow path, as indicated by the dotted straight arrow in Fig. 52. Then, it is vaporized again by the heat from the heat source, electronic component 30, and the above process is repeated.

[0241] As described above, according to the vapor chamber 101, the movement of the working fluid in the vapor flow path and the strong capillary force in the condensate flow path make the movement of the working fluid smooth and excellent, thereby improving the heat transport capacity. Furthermore, by forming a flow path in the vapor chamber 101 having a curved portion 107, even when the vapor chamber is placed in an electronic device and there are restrictions on its placement, making it impossible to form a flow path that is only in a straight line, the heat generated from the heat source can be efficiently transferred to a remote location. Furthermore, since the curved portion 107 is configured to reduce the difference in flow resistance among the multiple steam flow paths 104 as described above, the working fluid can be moved in a balanced manner, and the heat transport capacity can be increased.

[0242] 53 to 61 are diagrams for explaining a vapor chamber 201 according to a modified example. Fig. 53 is an external perspective view of the vapor chamber 201, and Fig. 54 is an exploded perspective view of the vapor chamber 201.

[0243] 53 and 54, the vapor chamber 201 has a first sheet 210, a second sheet 220, and a third sheet 230. The first sheet 210, the second sheet 220, and the third sheet 230 are stacked and joined (diffusion bonding, brazing, etc.) to form a hollow space surrounded by the first sheet 210, the second sheet 220, and the third sheet 230 between the first sheet 210 and the second sheet 220. The working fluid is sealed in this hollow space to form the sealed space 202.

[0244] In this embodiment, the first sheet 210 is a sheet-like member as a whole. The first sheet 210 is composed of flat surfaces on both sides, and has an inner surface 210a, an outer surface 210b opposite to the inner surface 210a, and a side surface 210c that spans the inner surface 210a and the outer surface 210b to form a thickness.

[0245] The first sheet 210 includes a main body 211 and an injection part 212. The main body 211 is a sheet-like part that forms an enclosed space through which the working fluid moves, and in this embodiment, is a rectangle with arcuate corners (so-called R) in plan view. Injection portion 212 is a portion where working fluid is injected into the sealed space formed by first sheet 210, second sheet 220, and third sheet 230, and in this embodiment, is a sheet-like shape that is rectangular in plan view and protrudes from the L-shaped body 211 in plan view. In this embodiment, injection portion 212 of first sheet 210 has flat surfaces on both the inner surface 210a side and the outer surface 210b side.

[0246] In this embodiment, the second sheet 220 is a sheet-like member as a whole. The second sheet 220 is composed of flat surfaces on both sides, and includes an inner surface 220a, an outer surface 220b opposite to the inner surface 220a, and a side surface 220c that spans the inner surface 220a and the outer surface 220b to form a thickness.

[0247] The second sheet 220 also has a body 221 and an injection portion 222 .

[0248] In this embodiment, the third sheet 230 is a sheet sandwiched and superimposed between the inner surface 210a of the first sheet 210 and the inner surface 220a of the second sheet 220, and a structure for moving the working fluid is formed in the main body 231. Figs. 55 and 56 show a plan view of the third sheet 230. Fig. 55 shows the surface superimposed on the second sheet 220, and Fig. 56 shows the surface superimposed on the first sheet 210. Fig. 57 shows the I in Fig. 55. 201 -I 201 In Fig. 58, the cut surface is shown along the line indicated by I in Fig. 55. 202 -I 202 The cross sections along the lines indicated by are shown.

[0249] The third sheet 230 includes a main body 231 and an injection portion 232. The main body 231 is a sheet-like portion that forms a sealed space in which the working fluid moves, and in this embodiment, is L-shaped with a curved portion in a plan view. Injection portion 232 is a portion where working fluid is injected into the sealed space formed by first sheet 210, second sheet 220, and third sheet 230, and in this embodiment, is a sheet-like shape that is rectangular in plan view and protrudes from main body 231 that is L-shaped in plan view. Injection portion 232 has injection groove 232a formed on the surface side that overlaps first sheet 210. Injection groove 232a can be considered to be similar to injection groove 122a described above.

[0250] The main body 231 includes an outer periphery joining portion 233 , an outer periphery liquid flow path portion 234 , an inner liquid flow path portion 235 , a steam flow path slit 236 , and a steam flow path connecting groove 237 .

[0251] The outer periphery bonding portion 233 is a portion formed along the outer periphery of the main body 231. One surface of the outer periphery bonding portion 233 is overlapped and bonded (diffusion bonding, brazing, etc.) to the surface of the first sheet 210, and the other surface is overlapped and bonded (diffusion bonding, brazing, etc.) to the surface of the second sheet 220. As a result, a hollow portion surrounded by the first sheet 210, the second sheet 220, and the third sheet 230 is formed, and a working fluid is sealed in this hollow portion to form an enclosed space. The peripheral joint 233 can be considered similar to the peripheral joint 113 described above.

[0252] The peripheral liquid flow path section 234 functions as a liquid flow path section and is a part that constitutes a part of the condensed liquid flow path 103, which is a flow path through which the working fluid passes when condensed and liquefied. The peripheral liquid flow path section 234 is formed along the inside of the peripheral joint section 233 of the main body 231, and is provided so as to be annular along the outer periphery of the sealed space 202. A liquid flow path groove 234a is formed on the surface of the peripheral liquid flow path section 234 that faces the second sheet 220. In this embodiment, the liquid flow path groove 234a is provided only on the surface that faces the second sheet 220, but in addition to this, a liquid flow path groove may also be provided on the surface that faces the first sheet 210. The outer circumferential liquid flow passage portion 234 and the liquid flow passage grooves 234a provided therein can be considered to be similar to the outer circumferential liquid flow passage portion 114 and the liquid flow passage grooves 114a described above.

[0253] The inner liquid flow path section 235 also functions as a liquid flow path section, and is a portion that constitutes a part of the condensed liquid flow path 103 through which the working fluid passes when condensed and liquefied. The inner liquid flow path section 235 is formed to extend with a curved portion inside the ring of the annular outer peripheral liquid flow path section 234 of the main body 231. A plurality of (five in this embodiment) inner liquid flow path sections 235 are arranged in a direction different from the extending direction, and are disposed between the steam flow path slits 236.

[0254] A liquid flow path groove 235a, which is a groove parallel to the extension direction of the inner liquid flow path section 235, is formed on the surface of the inner liquid flow path section 235 facing the second sheet 220. The inner liquid flow path section 235 and the liquid flow path groove 235a can be considered to be similar to the above-mentioned inner liquid flow path section 115 and the liquid flow path groove 115a. In this embodiment, the liquid flow path grooves 235 a are provided only on the surface facing the second sheet 220 , but in addition to this, liquid flow path grooves may also be provided on the surface facing the first sheet 210 .

[0255] The steam flow passage slit 236 is a portion where the working fluid in the vapor state and the condensed liquid state moves, and is a slit that constitutes the steam flow passage 104. The steam flow passage slit 236 is constituted by a slit having a curved portion that is formed inside the ring of the annular outer peripheral liquid flow passage section 234 in the main body 231. More specifically, the steam flow passage slit 236 in this embodiment is a slit that is formed between adjacent inner liquid flow passage sections 235 and between the outer peripheral liquid flow passage section 234 and the inner liquid flow passage section 235. Therefore, the steam flow passage slit 236 penetrates the third sheet 230 in the thickness direction (z direction). A plurality of (six in this embodiment) steam flow passage slits 236 are arranged in a direction different from the extending direction. Therefore, as can be seen from Fig. 60, the third sheet 230 has a shape in which the outer peripheral liquid flow passage portion 234, the inner liquid flow passage portion 235, and the steam flow passage slits 236 are alternately repeated.

[0256] Such a steam flow passage slit 236 can be considered to be similar to the aspect of the steam flow passage 104 formed by combining the steam flow passage groove 116 and the steam flow passage groove 126 described above.

[0257] In this embodiment, the cross-sectional shape of the steam flow path slit 236 is formed by overlapping parts of an ellipse, with the center in the thickness direction protruding, but is not limited to this and may be other shapes such as a square, rectangle, trapezoid or other quadrilateral, a triangle, a semicircle, a crescent, or a combination of these.

[0258] The steam flow passage communication groove 237 is a groove that forms a flow passage that communicates the multiple steam flow passage slits 236. This makes it possible to balance the movement of the working fluid that occurs in the steam flow passage in the direction in which the inner liquid flow passage section 235 extends. This also makes it possible to equalize the working fluid in the steam flow path, transport the steam over a wider area, and efficiently utilize the condensate flow paths defined by the many liquid flow path grooves 234a and 235a.

[0259] The steam flow path communication groove 237 in this embodiment is formed between both ends in the direction in which the inner liquid flow path section 235 extends and both ends in the direction in which the steam flow path slits 236 extend, and the outer circumferential liquid flow path section 234. The steam flow path communication groove 237 only needs to be able to communicate between adjacent steam flow path slits 236, and the shape thereof is not particularly limited, but it can be considered to be similar to a flow path formed by overlapping the above-mentioned steam flow path communication groove 117 and steam flow path communication groove 127.

[0260] The third sheet 230 also has a straight portion 238a, a straight portion 238b, and a curved portion 238c so that the condensate flow path 103 and the vapor flow path 104 have straight portions and curved portions in the sealed space of the vapor chamber 201. The concepts of these straight portions and curved portions are the same as those explained so far.

[0261] Such a third sheet 230 can be produced by etching each side separately, etching both sides simultaneously, pressing, cutting, or the like.

[0262] 59 to 61 are diagrams for explaining the structure when the first sheet 210, the second sheet 220, and the third sheet 230 are combined to form the vapor chamber 201. 203 -I 203 Fig. 60 shows an enlarged view of a part of Fig. 59. Fig. 61 shows the cross section along the line indicated by I in Fig. 53. 204 -I 204 The cross section along the line indicated by is shown.

[0263] As can be seen from Fig. 53 and Fig. 59 to Fig. 61, the first sheet 210, the second sheet 220, and the third sheet 230 are arranged so as to be overlapped and joined to form the vapor chamber 201. At this time, the inner surface 210a of the first sheet 210 and one surface of the third sheet 230 (the surface on the side on which the liquid flow path grooves 234a and 235a are not arranged) are arranged to face each other, and the inner surface 220a of the second sheet 220 and the other surface of the third sheet 230 (the surface on which the liquid flow path grooves 234a and 235a are arranged) are arranged to face each other. In the same manner, the injection section 212, the injection section 222, and the injection section 232 of each sheet are also overlapped.

[0264] As a result, a sealed space surrounded by the first sheet 210, the second sheet 220, and the third sheet 230 is formed between the first sheet 210 and the second sheet 220. A condensate flow path 103 and a steam flow path 104 are formed in this sealed space. Regarding the configuration of the condensate flow path 103 and the steam flow path 104 in this sealed space, the same concept as that of the condensate flow path 103 and the steam flow path 104 of the vapor chamber 101 described above can be applied.

[0265] In the above embodiment, the vapor chamber has been described as having a curved portion at the intersection when two straight portions intersect at 90 degrees to form an L-shape. However, the form of the curve is not limited to this, and the above-described curved portion can be applied to other forms. For example, the curved portion can be applied to each of the intersections when two straight portions extend in a direction intersecting a T-shape, when two straight portions extend in a direction intersecting a cross, when two straight portions intersect at an acute angle (an angle smaller than 90 degrees) to form a V-shape, and when two straight portions intersect at an obtuse angle (an angle larger than 90 degrees) to form a V-shape.

[0266] [Third Form] In the third form, since we will explain an intermediate body that is obtained during the production of the vapor chamber, which is the final product, a sheet on which this intermediate body is multi-sided, and a roll on which this sheet is wound, for convenience, we will show the production method and explain along with it, while explaining the structure of the obtained intermediate body, sheet on which the intermediate body is multi-sided, and roll on which the intermediate body is multi-sided.

[0267] << Vapor chamber manufacturing method S1 >> Fig. 62 shows a flow of a manufacturing method S301 of a vapor chamber according to one embodiment (hereinafter, may be referred to as "manufacturing method S301"). As can be seen from Fig. 62, the manufacturing method S301 includes the steps of manufacturing a multi-faceted intermediate sheet / multi-faceted intermediate roll S310, manufacturing an intermediate S320, forming an injection port S330, injecting liquid S340, and sealing S350. For convenience, in the following, a "sheet having an intermediate body for a vapor chamber attached on multiple sides" may be referred to as a "multi-sided intermediate sheet," and a "roll around which a sheet having an intermediate body for a vapor chamber attached on multiple sides" may be referred to as a "multi-sided intermediate roll." Each step will be described in detail below.

[0268] <Material> Prior to the manufacturing method S301, materials are prepared. In this embodiment, the vapor chamber is manufactured by bonding two sheets, so two material sheets are prepared. As described below, in this embodiment, the vapor chamber is not produced from two material sheets one by one, but rather, two long, strip-shaped material sheets are overlapped to produce a multi-faceted intermediate sheet or a multi-faceted intermediate roll in which multiple intermediates are arranged, and then the intermediates are individually punched out to produce the vapor chamber, a so-called "multi-face" process is carried out. Therefore, the material sheets prepared in this embodiment are two long, strip-shaped sheets, and are usually provided as rolls in which the strip-shaped sheets are wound. However, the present disclosure can also be applied to the manufacturing methods of intermediate bodies produced on a sheet-by-sheet basis, except for the processes specific to multi-faceting, and vapor chambers produced on a sheet-by-sheet basis.

[0269] The material constituting the material sheet is not particularly limited, but metal can be used. Among them, metals with high thermal conductivity are preferable. Examples of such metals include copper, copper alloys, and aluminum. However, the material does not necessarily have to be a metal, and ceramics such as AlN, Si3N4, or Al2O3, or resins such as polyimide and epoxy are also possible. In addition, a single sheet made of two or more laminated materials (so-called clad material or the first sheet 10 and second sheet 20 described in the vapor chamber 1) may be used, or different materials may be used depending on the location.

[0270] The thickness of the material sheets can be considered to be similar to that of the first sheet 10, the second sheet 20 of the vapor chamber 1, the first sheet 110, the second sheet 120 of the vapor chamber 101, and so on.

[0271] <Manufacturing of multi-layered intermediate sheets and multi-layered intermediate rolls S310> In the manufacturing step S310 of a multi-component intermediate sheet / multi-component intermediate roll (hereinafter sometimes referred to as "step S310"), a multi-component intermediate sheet and / or a multi-component intermediate roll are manufactured from the above-mentioned materials. Figure 63 shows the flow of step S310. As can be seen from Figure 63, step S310 includes the steps of processing S311 and joining S312.

[0272] (Processing S311) Processing S311 is a process of forming a shape for the flow path of the vapor chamber. In this embodiment, the shape is formed in one of the two material sheets, the multi-faceted first sheet 301, and the other material sheet, the multi-faceted second sheet 302, is used without processing for the flow path. FIG. 64 shows a diagram explaining the multi-faceted first sheet 301 to which a shape 310 has been given after processing. As can be seen from this figure, a plurality of shapes 310 for the flow path of the vapor chamber are arranged in the multi-faceted first sheet 301, forming the sheet 301 with the shapes 310 attached in a multi-faceted manner, and this sheet 301 is wound into a roll.

[0273] The method of forming the shape 310 is not particularly limited, and examples thereof include etching, cutting, and pressing. Among these, forming the shape by etching is more efficient and suitable for mass production than other methods. In this case, so-called half etching can be applied, in which etching is performed halfway through the material sheet without penetrating it in the thickness direction.

[0274] Here, the specific form of the shape 310 is not particularly limited, but for example, the following forms can be used. Figs. 65 to 67 are diagrams for explaining one example form. Fig. 65 is an external perspective view focusing on one of the multi-faceted shapes 310 in Fig. 64. Fig. 66 shows a view of Fig. 65 as seen from the z direction (plan view). Fig. 67 shows the I in Fig. 66. 301 -I 301 The cross-sectional view is shown when cut at .

[0275] The shape to be given is a groove that becomes a flow path for the working fluid to return, and a groove that becomes a flow path for injecting the working fluid into the groove. Specifically, in this embodiment, the outer circumferential liquid flow path section 314, the inner liquid flow path section 315, the steam flow path groove 316, the steam flow path connecting groove 317, and the injection groove 318 are provided.

[0276] The outer circumferential liquid flow path portion 314 functions as a liquid flow path portion, and is a portion that constitutes a condensed liquid flow path 354 (see FIG. 84, etc.), which is a second flow path through which the working fluid passes when it is condensed and liquefied. 302 The part shown in Figure 69 is I 303 -I 303 In each of the drawings, the cross-sectional shape of the outer peripheral liquid flow path portion 314 is shown. 304 1 shows an enlarged view of a part of the outer circumferential liquid flow path section 314 as viewed from the direction indicated by (z direction, plan view).

[0277] As can be seen from these figures, the outer peripheral liquid flow passage section 314 is a portion configured in an annular shape. The outer peripheral liquid flow passage section 314 is provided with liquid flow passage grooves 314a that are grooves extending along the annular direction, and the liquid flow passage grooves 314a are arranged at a predetermined interval in a direction different from the direction in which the liquid flow passage grooves 314a extend. Therefore, as can be seen from Figures 68 and 69, the outer peripheral liquid flow passage section 314 has liquid flow passage grooves 314a that are recesses in the cross section, and protrusions 314b between the liquid flow passage grooves 314a, which are repeated in a concave and convex manner. In this embodiment, in the outer peripheral liquid flow passage section 314, as can be seen from Figure 70, adjacent liquid flow passage grooves 314a communicate with each other at a predetermined interval through communication openings 314c.

[0278] The shape of the peripheral liquid flow path portion 314 can be considered to be similar to the peripheral liquid flow path portion of each of the above-mentioned shapes of the vapor chamber.

[0279] The inner liquid flow path portion 315 also functions as a liquid flow path portion, and is a portion that constitutes a condensed liquid flow path 354, which is a second flow path through which the working fluid flows when it is condensed and liquefied. 305 The cross-sectional shape of the inner liquid flow path portion 315 is also shown in FIG. 72. Also, FIG. 72 shows the portion indicated by the arrow I in FIG. 306 13 shows an enlarged view of a part of the inner liquid flow path section 315 as viewed from the direction indicated by (as viewed from the z direction, in plan view).

[0280] As can be seen from these figures, the inner liquid flow path section 315 is formed inside the annular ring of the outer peripheral liquid flow path section 314. As can be seen from Figures 65 and 66, the inner liquid flow path section 315 in this embodiment is a wall extending in the x direction, and multiple (three in this embodiment) inner liquid flow paths are arranged at predetermined intervals in the direction perpendicular to the extending direction (y direction). Each inner liquid flow path section 315 is formed with liquid flow path grooves 315a which are parallel to the direction in which the inner liquid flow path section 315 extends, and the liquid flow path grooves 315a are arranged at predetermined intervals in a direction different from the direction in which the liquid flow path grooves 315a extend. Therefore, as can be seen from Figures 67 and 71, in the cross section of the inner liquid flow path section 315, the liquid flow path grooves 315a which are recesses and the convex stripes of the convex portions 315b between the liquid flow path grooves 315a are formed in a repeated concave-convex pattern. As can be seen from Figure 72, adjacent liquid flow path grooves 315a communicate with each other via communication openings 315c at predetermined intervals.

[0281] The shape of such an inner liquid flow path portion 315 can be considered to be similar to the inner liquid flow path portions of the vapor chambers of the above-mentioned respective shapes.

[0282] The vapor flow passage groove 316 is a portion through which vaporized vapor generated when the working fluid evaporates passes, and constitutes a part of the vapor flow passage 355 (see FIG. 84, etc.), which is the first flow passage. FIG. 66 shows the shape of the vapor flow passage groove 316 as viewed from the z direction, and FIG. 67 shows the cross-sectional shape of the vapor flow passage groove 316.

[0283] As can be seen from these figures, the steam flow path groove 316 is formed as a groove formed inside the annular ring of the outer circumferential liquid flow path section 314. More specifically, the steam flow path groove 316 in this embodiment is formed between adjacent inner liquid flow path sections 315 and between the outer circumferential liquid flow path section 314 and the inner liquid flow path section 315, and is a groove extending in the extension direction of the inner liquid flow path section 315 (x direction). A plurality of (four in this embodiment) steam flow path grooves 316 are arranged in a direction perpendicular to the extension direction (y direction). Therefore, as can be seen from FIG. 67, in the y direction, the shape has a repeated unevenness with the outer circumferential liquid flow path section 314 and the inner liquid flow path section 315 as convex stripes and the steam flow path groove 316 as concave stripes.

[0284] The shape of the vapor flow passage groove 316 can be considered to be similar to the vapor flow passage groove of each of the above-mentioned shapes of the vapor chamber.

[0285] The steam flow passage communication groove 317 is a groove that communicates the multiple steam flow passage grooves 316. This makes it possible to equalize the steam in the multiple steam flow passages 355, transport the steam over a wider range, and efficiently utilize many condensate flow passages 354, thereby making it possible to more smoothly return the working fluid. The shape of the vapor passage communication groove 317 can be considered to be similar to the vapor passage communication groove of each of the vapor chambers described above.

[0286] The injection groove 318 is a groove for injecting the working fluid into the steam flow path groove 316. As can be seen from Figures 65 and 66, in this embodiment, the injection groove 318 is a groove that is connected to the steam flow path connecting groove 317 so as to cross the outer circumferential liquid flow path portion 314.

[0287] (Joint S312) In the joining S312 shown in Figure 63, the multi-faceted first sheet 301 and the multi-faceted second sheet 302 prepared in the processing S311 as described above are overlapped and joined to produce a multi-faceted intermediate sheet 350 and a multi-faceted intermediate roll 351 formed by rolling up the same. The bonding method is not particularly limited, and specific examples include diffusion bonding, brazing, irradiation, etc. Here, bonding by irradiation will be described as an example. A diagram for explanation is shown in Figure 73. In this embodiment, all of these bonding methods are performed in a vacuum chamber 360 connected to a vacuum pump (not shown).

[0288] A multi-imposition first sheet 301 and a multi-imposition second sheet 302 are each unwound from a roll.

[0289] Next, the surface of the unwound multi-faceted first sheet 301 on which the above-mentioned shape 310 is formed is irradiated with at least one of an atomic beam, an ion beam, and plasma from an irradiation device 361. Here, the atomic beam that is irradiated refers to a group of neutral atoms traveling in a fixed direction as a thin bundle of rays, an ion beam refers to ions accelerated by an electric field, and plasma refers to a state in which the molecules that make up a gas are ionized and separated into positive ions and electrons. As a result, the oxide film on the surface of the multiple-imposition first sheet 301 that has been irradiated is removed.

[0290] Similarly, the surface of the unwound multi-imposed second sheet 302 that is to be superimposed on the multi-imposed first sheet 301 is irradiated with at least one of an atomic beam, an ion beam, and plasma from an irradiation device 362 . As a result, the oxide film on the surface of the multi-faceted second sheet 302 that has been irradiated is removed.

[0291] The surfaces of multi-imposed first sheet 301 and multi-imposed second sheet 302 irradiated as described above are overlapped and pressed by pressure roll 363. As a result, multi-imposed first sheet 301 and multi-imposed second sheet 302 are joined to form multi-imposed intermediate sheet 350. This multi-imposed intermediate sheet 350 is then wound up to form multi-imposed intermediate roll 351.

[0292] In this way, by irradiating the joining surfaces of the sheets to be joined as described above and then joining them, the oxide film is removed and there is no need to perform joining at high temperatures, so that deterioration of the material can be suppressed. In particular, as the vapor chamber becomes thinner, such deterioration of the material is likely to cause problems such as poor sealing of the working fluid, so the occurrence of such problems can be suppressed. In addition to removing the oxide film on the bonding surface, the oxide film on the inside of liquid flow path groove 314a, liquid flow path groove 315a, vapor flow path groove 316, and vapor flow path connecting groove 317 can also be removed, thereby increasing the wettability of the inner surfaces and improving the heat transport performance of the vapor chamber.

[0293] The oxide film removal effect and the resulting improvement in heat transport performance can also be observed in diffusion bonding and brazing.

[0294] Fig. 74 shows the external appearance of a multi-imposed intermediate sheet 350 and a multi-imposed intermediate roll 351. In Fig. 74, a shape 310 is disposed between a multi-imposed first sheet 301 and a multi-imposed second sheet 302, and is not visible from the outside and is represented by a dotted line. 75 shows a cross section of a portion of one of the multi-faceted shapes 310 of the multi-faceted intermediate sheet 350. This cross section is viewed from the same perspective as in FIG.

[0295] As can be seen from these figures, in the multi-faceted intermediate sheet 350 and the multi-faceted intermediate roll 351, the openings of the liquid flow path groove 314a, the liquid flow path groove 315a, the steam flow path groove 316, and the steam flow path connecting groove 317 are closed by the multi-faceted second sheet 302, forming a hollow portion. In this embodiment, the hollow portion is configured so that the oxygen concentration is 1% or less, preferably 0.1% or less, and more preferably 500 ppm or less. This hollow portion is isolated from the outside and does not communicate with the outside of multi-imposed intermediate sheet 350 and multi-imposed intermediate roll 351, so this oxygen concentration is maintained. According to this, even when the multi-faceted intermediate sheet 350 or the multi-faceted intermediate roll 351 is stored, transported, or otherwise not immediately processed into a vapor chamber, the inside of the hollow portion can be maintained in a state of low oxygen concentration, thereby suppressing the formation of an oxide film on the inner surface of the hollow portion. Therefore, even if a vapor chamber is subsequently produced using this multi-faceted intermediate sheet 350, there will be little oxide film on the inner surface of the flow paths (condensate flow path 354, steam flow path 355), making it possible to provide a vapor chamber with good heat transport performance.

[0296] One way to achieve this is to create a vacuum inside the hollow section. Here, the "vacuum state" does not necessarily mean a complete vacuum, but may be, for example, a pressure of 134 Pa or less (1 Torr or less).

[0297] The method for creating a vacuum state inside the hollow portion is not particularly limited, but for example, as described above, it is possible to perform the bonding in a vacuum atmosphere when bonding the multi-sided first sheet 301 and the multi-sided second sheet 302. Bonding in a vacuum atmosphere is possible not only by the above-mentioned bonding by irradiation, but also by diffusion bonding or brazing.

[0298] In addition, in this embodiment, the hollow portions of the multi-imposed intermediate sheet 350 and the multi-imposed intermediate roll 351 are in a vacuum state, but as long as the oxygen concentration can be suppressed to suppress the generation of an oxide film on the inner surface of the hollow portions, the hollow portions may be configured to contain an inert gas such as nitrogen or argon instead of a vacuum state. This also makes it possible to suppress the oxygen concentration in the hollow portions and suppress the generation of an oxide film. In this case, too, by performing the joining using a joining method that allows joining in an inert gas atmosphere, it is possible to contain the inert gas in the hollow portion.

[0299] The hollow portion may contain moisture.

[0300] Even if the hollow portion contains air and the oxygen concentration is greater than 1%, the hollow portion is isolated from the outside as described above and there is no air exchange, so the generation of an oxide film is suppressed compared to when the hollow portion is connected to the outside. Therefore, even if a configuration in which air is contained in the hollow portion is adopted, the above effect can be obtained, although to a lesser extent.

[0301] <Production of intermediates S320> 62, in manufacturing intermediate body S320, intermediate body 352 is manufactured from multi-faceted intermediate body sheet 350 and multi-faceted intermediate body roll 351. Specifically, intermediate body 352 is obtained by taking out individual intermediate bodies 352 from multi-faceted intermediate body sheet 350 on which objects to become intermediate bodies 352 are multi-faceted, using a known method such as punching. Fig. 76 is an external perspective view of intermediate body 352, and Fig. 77 is a view of intermediate body 352 as seen from the z direction (plan view). In Fig. 77, the shape of a hollow portion formed inside intermediate body 352 is shown by a dotted line.

[0302] 76 and 77, the hollow portion is also isolated from the outside in intermediate body 352. This prevents the formation of an oxide film on the inner surface of the hollow portion even in the state of intermediate body 352. Therefore, in this embodiment, intermediate body 352 may be stored and transported.

[0303] Figure 77 shows the W 301 The width of the joint shown in can be set appropriately as needed, but this width W 301 The width W is preferably 3.0 mm or less, may be 2.5 mm or less, or may be 2.0 mm or less. 301 If the width W is larger than 3.0 mm, the internal volume of the space for the flow path of the working fluid becomes small, and there is a risk that the steam flow path and the condensate flow path cannot be sufficiently secured. 301 The width W is preferably 0.2 mm or more, may be 0.6 mm or more, or may be 0.8 mm or more. 301 If the width W is less than 0.2 mm, there is a risk that the joining area will be insufficient if a positional shift occurs during joining of the first sheet and the second sheet. 301 The range of width W 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. 301 The range may be determined by any two combinations of multiple upper limit candidate values, or any two combinations of multiple lower limit candidate values.

[0304] <Formation of injection port S330> In forming an injection port S330 shown in Fig. 62, an opening for injecting a working fluid into the hollow portion is formed. Therefore, in this embodiment, an opening that communicates with injection groove 318 from the outside is formed in intermediate body 352. Figs. 78 and 79 show one example of the shape of injection port 319, and Figs. 80 and 81 show another example of the shape of injection port 319.

[0305] In the example shown in FIGS. 78 and 79, an injection port 319 is formed by drilling a hole in the z direction (thickness direction) in the intermediate body 352, and the injection groove 318 communicates with the outside. In contrast to this, in the example shown in Figures 80 and 81, an injection port 319 is formed by removing the end face of the intermediate body 352, and the injection groove 318 communicates with the outside.

[0306] In this embodiment, an injection port is opened in intermediate 352, but in other cases where multi-faceted intermediate sheet 350 and multi-faceted intermediate roll 351 are stored and transported, and a vapor chamber is created immediately after intermediate 352 is removed, injection port 319 may be formed in multi-faceted intermediate sheet 350 at a stage before it is made into intermediate 352. In this case, therefore, the injection port 319 is formed before or at the same time as the intermediate body 352 is removed.

[0307] <Injection S340> 62, injecting S340, the working fluid is injected into the hollow portion using the formed injection port 319. The injection method is not particularly limited, and a known method can be applied.

[0308] The type of working fluid is not particularly limited, but working fluids used in ordinary vapor chambers, such as pure water, ethanol, methanol, acetone, and mixtures thereof, can be used.

[0309] <Sealing S350> In sealing S350, with the working fluid being filled, the filling groove 318 is closed. The method for closing is not particularly limited, but examples thereof include crimping and welding.

[0310] [Vapor chamber] The vapor chamber 353 manufactured as described above has the following structure. Fig. 82 to Fig. 84 are diagrams for explanation. Fig. 82 is a perspective view of the vapor chamber 353, Fig. 83 is a view of the vapor chamber 353 from the z direction, and Fig. 84 is a perspective view of the vapor chamber 353 from the z direction.307 -I 307 83 is a cross-sectional view taken along the line indicated by the arrow A. In FIG. 83, the inner structure is shown by dotted lines.

[0311] The inside of the vapor chamber 353 is made into a sealed space by sealing the working fluid in the hollow portion of the intermediate body 352 . Specifically, this sealed space is provided with a condensate flow path 354 which is a second flow path through which condensate, which is the working fluid condensed and liquefied, flows via liquid flow path grooves 314a and 315a, and a steam flow path 355 which is a first flow path through which steam, which is the working fluid condensed and vaporized, flows via steam flow path grooves 316. Furthermore, this sealed space is provided with a flow path that communicates with the steam flow path 355 via steam flow path communication grooves 317. In this way, the condensate flow path 354, which is the second flow path, is formed separately from the steam flow path 355, which is the first flow path, and therefore the working fluid can circulate smoothly. In addition, by forming the condensate flow path 354 as a thin flow path surrounded by walls on all four sides in cross section, the condensate is moved by strong capillary force, enabling smooth circulation.

[0312] Here, the flow path cross-sectional area of ​​the condensate flow path 354, which is the second flow path, is smaller than the flow path cross-sectional area of ​​the steam flow path 355, which is the first flow path. More specifically, the average flow path cross-sectional area of ​​two adjacent steam flow paths 355 (in this embodiment, the steam flow path 355 formed by one steam flow path groove 316) is defined as A g The average flow path cross-sectional area of ​​the plurality of condensate flow paths 354 (the plurality of condensate flow paths 354 formed by one inner liquid flow path section 315 in this embodiment) arranged between two adjacent steam flow paths 355 is defined as A l Then, the condensate flow path 354 and the steam flow path 355 are A l A g The relationship is 0.5 times or less, and preferably 0.25 times or less, so that the working fluid can easily selectively pass through the first flow path and the second flow path depending on its phase (gas phase, liquid phase). This relationship needs to be satisfied in at least a portion of the entire vapor chamber, and it is more preferable that this relationship be satisfied in the entire vapor chamber.

[0313] This vapor chamber 353 can be attached to an electronic device and function in the same manner as the other types of vapor chambers described above. In this embodiment, as described above, during the manufacturing process, the multi-faceted intermediate sheet 350, the multi-faceted intermediate roll 351, and the intermediate 352 are maintained in a state in which an oxide film is unlikely to form on the inner surfaces of the hollow portions (condensate flow path 354, steam flow path 355). This results in good wettability of the inner surfaces of the condensate flow path 354 and the steam flow path 355, thereby improving the smooth flow and heat transfer of the working fluid. In particular, in a configuration such as the present embodiment in which high heat transport capacity is obtained by thinning the vapor chamber while increasing the inner surface area of ​​the flow path and thereby increasing the heat transfer area, the effect of the oxide film becomes relatively large, so by adopting the configuration disclosed herein, the effect of exerting heat transport capacity is remarkable.

[0314] In this embodiment, an example is shown in which liquid flow path grooves 314a, liquid flow path grooves 315a, and steam flow path grooves 316 are provided only in the multi-faceted first sheet 301, but as shown in Figure 85, steam flow path grooves 326 may also be provided in the multi-faceted second sheet 302, and as shown in Figure 86, liquid flow path grooves 324a, liquid flow path grooves 325a, and steam flow path grooves 326 may also be provided in the multi-faceted second sheet 302. In this example, the multi-imposed intermediate sheet, multi-imposed intermediate roll, intermediate, and vapor chamber of the present disclosure can also be used.

[0315] Furthermore, it is not limited to being made up of two multi-faceted sheets, but may also be a multi-faceted intermediate sheet made up of three multi-faceted sheets as shown in Figure 87, a multi-faceted intermediate roll, an intermediate produced from this, and a vapor chamber.

[0316] The multi-imposed intermediate sheet shown in FIG. 87 is a laminate of a multi-imposed first sheet 301, a multi-imposed second sheet 302, and a multi-imposed intermediate sheet 303 (a multi-imposed third sheet 303). A multi-imposed intermediate sheet 303 is disposed so as to be sandwiched between a multi-imposed first sheet 301 and a multi-imposed second sheet 302, and these are joined together in the same manner as in the above-mentioned example.

[0317] In this example, both surfaces of a multi-imposition first sheet 301 and a multi-imposition second sheet 302 are flat. At this time, the thickness of the multi-imposition first sheet 301 and the multi-imposition second sheet 302 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, this thickness is preferably 0.005 mm or more, may be 0.015 mm or more, or may be 0.030 mm or more. This thickness range may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Also, this thickness range may be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values.

[0318] The multiple-implant intermediate sheet 303 is provided with a steam flow passage groove 336, an outer peripheral liquid flow passage portion 334, an inner liquid flow passage portion 335, a liquid flow passage groove 334a, and a liquid flow passage portion 335a. The steam flow path groove 336 is a groove that penetrates the multi-sided intermediate sheet 303 in the thickness direction, and is a groove similar to the groove that constitutes the steam flow path 355, which is the first flow path, by the steam flow path groove 316 described above, and is arranged in a form corresponding to the groove. The outer circumferential liquid flow path portion 334 and liquid flow path groove 334a can be considered to be the same as the outer circumferential liquid flow path portion 314 and liquid flow path groove 314a described above, and the outer circumferential liquid flow path portion 335 and liquid flow path groove 335a can be considered to be the same as the outer circumferential liquid flow path portion 315 and liquid flow path groove 315a described above.

[0319] The above-mentioned examples of the embodiments of the present disclosure are not limited to the above, and the components can be modified without departing from the spirit of the present disclosure. In addition, various embodiments can be realized by appropriately combining the multiple components disclosed in the above-mentioned embodiments. Some components may be deleted from all the components shown in each embodiment. [Explanation of symbols]

[0320] 1, 101 Vapor chamber 2, 102 Closed space 3, 103 Condensate flow path 4, 104 Steam flow path 10, 110 First sheet 10a Inner surface 10b External surface 10c side 10d Inner layer 10e outer layer 11, 111 Main unit 12, 112 Injection part 13, 113 Peripheral joint 14, 114 Peripheral liquid flow path section 14a, 114a Liquid flow groove 14c, 114c communication opening 15, 115 Inner liquid flow path section 15a, 115a Liquid flow groove 15c, 115c communication opening 16, 116 Steam flow groove 17, 117 Steam flow passage connecting groove 20, 120 Second sheet 20a Inner surface 20b External surface 20c side 20d inner layer 20e outer layer 21, 121 Main unit 22, 122 Injection part 23, 123 Peripheral joint 24, 124 Peripheral liquid flow path section 25, 125 Inner liquid flow path section 26, 126 Steam flow groove 27, 127 Steam flow passage connecting groove 30 Electronic Components 40 Electronic devices (mobile terminals) 41 Case 50, 230 3rd seat 236 Steam flow passage slit 301 Multi-layer first sheet 302 Multi-face second sheet 350 Multi-layer intermediate sheet 351 Multi-face intermediate roll 352 Intermediates 353 Vapor Chamber

Claims

1. An intermediate for a vapor chamber, comprising: a hollow portion to serve as a flow path for a working fluid is provided inside the intermediate body, No working fluid is injected into the hollow portion, The hollow portion is sealed off from the outside. Intermediate.

2. The intermediate body according to claim 1 , wherein the hollow portion does not have an inlet for injecting the working fluid.

3. 2. The intermediate according to claim 1, wherein the oxygen concentration in the hollow portion is 1% or less.

4. 2. The intermediate according to claim 1, wherein the pressure inside the hollow portion is 134 Pa or less.

5. 2. The intermediate according to claim 1, wherein an inert gas is contained within the hollow portion.

6. The intermediate according to claim 1 , wherein moisture is contained within the hollow portion.

7. A sheet comprising the intermediate product according to any one of claims 1 to 6 laminated on multiple surfaces.

8. A roll of the sheet of claim 7.

9. 1. A method for producing a vapor chamber from an intermediate, comprising the steps of: The intermediate body has a hollow portion therein to serve as a flow path for the working fluid, a step of producing a sheet having the intermediate body laminated thereon in a multi-faceted manner while the working fluid is not injected into the hollow portion and the hollow portion is isolated from the outside; removing the individual intermediate bodies from the sheet to produce the intermediate bodies; forming an inlet for injecting the working fluid into the hollow portion; an injecting step of injecting the working fluid through the inlet; and a sealing step of closing the inlet with the working fluid injected. A method for manufacturing a vapor chamber.

10. The step of producing a sheet having the intermediate body laminated in a multi-faceted state includes: forming a shape for a vapor chamber flow path in a plurality of sheets of material; A joining step of joining together the plurality of material sheets prepared in the processing step, The method for manufacturing a vapor chamber according to claim 9 , further comprising removing an oxide film on the joining surface of the material sheet before the joining step.

11. The method for manufacturing a vapor chamber according to claim 9 , wherein the step of forming the injection port is performed after the step of manufacturing the intermediate body.

12. The method for manufacturing a vapor chamber according to claim 9 , wherein the step of forming the injection port is performed after the step of manufacturing a sheet having the intermediate body laminated in multiple layers and before the step of manufacturing the intermediate body.

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