A sheet with multiple layers of intermediates for a vapor chamber attached, a roll on which the sheet with multiple layers of intermediates for a vapor chamber is wound, an intermediate for a vapor chamber, and a method for manufacturing a vapor chamber.

Abstract

The present invention provides an intermediate that is less prone to the formation of an oxide film on the inner surface of a fluid channel through which a working fluid flows, a sheet with multiple surfaces of the intermediate, a roll wound with the intermediate, and a method for manufacturing a vapor chamber. [Solution] An intermediate body 352 for a vapor chamber, wherein the intermediate body has a hollow section inside which the working fluid is to flow through, the working fluid is not injected into the hollow section, and the hollow section is isolated from the outside.

Description

Technical Field

[0001] The present disclosure relates to a vapor chamber that performs heat transport by refluxing a working fluid enclosed in a sealed space while undergoing a phase change.

Background Art

[0002] The amount of heat generated from electronic components such as a CPU (Central Processing Unit) provided in personal computers and portable terminals such as mobile phones and tablet terminals tends to increase due to the improvement of information processing capabilities, and cooling technology is important. As such a means for cooling, a heat pipe is well known. This diffuses the heat at the heat source by transporting the heat at the heat source to other parts by a working fluid enclosed in the pipe, and cools the heat source.

[0003] On the other hand, in recent years, particularly in portable terminals such as mobile phones, thinning has been remarkable, and a cooling means thinner than a conventional heat pipe has been required. In response, for example, vapor chambers as described in Patent Documents 1 to Patent Documents 3 have been proposed.

[0004] A vapor chamber is a device that expands the concept of heat transport by a heat pipe to a flat member. That is, in the vapor chamber, a working fluid is enclosed between opposing flat plates, and this working fluid performs heat transport while undergoing a phase change, transports and diffuses the heat at the heat source, and cools the heat source.

[0005] More specifically, a flow path for the working fluid is provided between opposing plates in the vapor chamber, and the working fluid is sealed within this flow path. When the vapor chamber is placed near a heat source, the working fluid absorbs heat from the heat source and evaporates near the heat source, becoming a gas (vapor) and moving through the flow path. This smoothly transports the heat from the heat source to a location away from it, resulting in the cooling of the heat source. The gaseous working fluid, having transported heat from the heat source, moves to a location away from the heat source, where it cools and condenses as it absorbs heat from its surroundings, undergoing a phase change to a liquid state. The liquid working fluid, having undergone the phase change, travels through other flow paths, returns to the heat source, absorbs heat from it again, evaporates, and changes back to a gaseous state. Through this circulation, the heat generated from the heat source is transported to a location away from the heat source, thereby cooling the heat source. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 5788069 [Patent Document 2] Japanese Patent Publication No. 2016-205693 [Patent Document 3] Patent No. 6057952 [Overview of the project] [Problems that the invention aims to solve]

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

[0008] The present invention discloses an intermediate for a vapor chamber, wherein the intermediate has a hollow portion inside which a working fluid is to be a passage for the working fluid, the working fluid is not injected into the hollow portion, and the hollow portion is isolated from the outside. [Effects of the Invention]

[0009] According to this disclosure, an intermediate can be obtained in which an oxide film is less likely to form on the inner surface of the flow path through which the working fluid flows. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of the vapor chamber 1. [Figure 2] Figure 2 is an exploded perspective view of the vapor chamber 1. [Figure 3] Figure 3 is a perspective view of the first sheet 10. [Figure 4] Figure 4 is a plan view of the first sheet 10. [Figure 5] Figure 5 shows a cross-section of the first sheet 10. [Figure 6] Figure 6 shows another cross-section of the first sheet 10. [Figure 7] Figure 7 shows another cross-section of the first sheet 10. [Figure 8] Figure 8 is a plan view of the outer peripheral fluid flow channel 14, with a portion of it enlarged. [Figure 9] Figure 9 is a plan view of a portion of the outer peripheral fluid flow channel 14 of another example, with some parts enlarged. [Figure 10] Figure 10 is a plan view of the outer peripheral fluid flow channel 14 of another example, with a portion of it enlarged. [Figure 11] Figure 11 is a plan view of the outer peripheral fluid flow channel 14 of another example, with a portion of it enlarged. [Figure 12] Figure 12 is a plan view of a portion of the outer peripheral fluid flow channel 14 of another example, with some parts enlarged. [Figure 13] Figure 13 is a cross-sectional view focusing on the inner liquid flow channel 15. [Figure 14] Figure 14 is a plan view of the inner liquid flow channel section 15, with a portion of it enlarged. [Figure 15] Figure 15 is a perspective view of the second sheet 20. [Figure 16] Figure 16 is a plan view of the second sheet 20. [Figure 17] Figure 17 shows a cross-section of the second sheet 20. [Figure 18] Figure 18 shows a cross-section of the second sheet 20. [Figure 19] Figure 19 shows a cross-section of vapor chamber 1. [Figure 20] Figure 20 is an enlarged view of a portion of Figure 19. [Figure 21] Figure 21 shows another cross-section of the vapor chamber 1. [Figure 22A] Figure 22A is a diagram illustrating the manufacturing process of the vapor chamber 1. [Figure 22B] Figure 22B is a diagram illustrating the manufacturing process of the vapor chamber 1. [Figure 22C] Figure 22C is a diagram illustrating the manufacturing process of the vapor chamber 1. [Figure 22D] Figure 22D is a diagram illustrating the manufacturing process of the vapor chamber 1. [Figure 23] Figure 23 is a diagram illustrating the electronic device 40. [Figure 24] Figure 24 is a diagram illustrating the flow of the working fluid. [Figure 25] Figure 25 illustrates a modified vapor chamber. [Figure 26] Figure 26 illustrates a modified vapor chamber. [Figure 27] Figure 27 is a perspective view of the vapor chamber 101. [Figure 28] Figure 28 is an exploded perspective view of the vapor chamber 101. [Figure 29] Figure 29 is a perspective view of the first sheet 110. [Figure 30] Figure 30 is a plan view of the first sheet 110. [Figure 31] Figure 31 shows a cross-section of the first sheet 110. [Figure 32] Figure 32 shows another cross-section of the first sheet 110. [Figure 33] Figure 33 shows another cross-section of the first sheet 110. [Figure 34] Figure 34 is a plan view of the outer peripheral fluid flow channel 114, with a portion of it enlarged. [Figure 35] Figure 35 is a cross-sectional view focusing on the inner liquid flow channel 115. [Figure 36] Figure 36 is a plan view of the inner liquid flow channel section 115, with a portion of it enlarged. [Figure 37] Figure 37 illustrates an example of the shape of the curved portion 118c. [Figure 38] Figure 38 illustrates an example of the shape of the curved portion 118c. [Figure 39] Figure 39 illustrates an example of the shape of the curved portion 118c. [Figure 40] Figure 40 illustrates an example of the shape of the curved portion 118c. [Figure 41] Figure 41 is a perspective view of the second sheet 120. [Figure 42] Figure 42 is a plan view of the second sheet 120. [Figure 43] Figure 43 shows a cross-section of the second sheet 120. [Figure 44] Figure 44 shows another cross-section of the second sheet 120. [Figure 45] Figure 45 shows a cross-section of the vapor chamber 101. [Figure 46] Figure 46 is an enlarged view of a portion of Figure 45. [Figure 47] Figure 47 shows another cross-section of the vapor chamber 101. [Figure 48] Figure 48 illustrates an example of the condensate flow path configuration. [Figure 49] Figure 49 illustrates an example of the condensate flow path configuration. [Figure 50] Figure 50 illustrates an example of the condensate flow path configuration. [Figure 51] Figure 51 illustrates the condensate flow path 103 and the vapor flow path 104. [Figure 52] Figure 52 is a diagram illustrating the operation of the vapor chamber 101. [Figure 53] Figure 53 is an external perspective view of the vapor chamber 201. [Figure 54]Figure 54 is an exploded perspective view of the vapor chamber 201. [Figure 55] Figure 55 is a view of the third sheet 230 from one side. [Figure 56] Figure 56 is a view of the third sheet 230 from the other side. [Figure 57] Figure 57 shows a cross-section of the third sheet 230. [Figure 58] Figure 58 shows another cross-section of the third sheet 230. [Figure 59] Figure 59 shows a cross-section of the vapor chamber 201. [Figure 60] Figure 60 is an enlarged view of a portion of Figure 59. [Figure 61] Figure 61 shows another cross-section of the vapor chamber 201. [Figure 62] Figure 62 is a diagram showing the flow of the vapor chamber manufacturing method S301. [Figure 63] Figure 63 is a diagram showing the flow of process S310. [Figure 64] Figure 64 is a perspective view of the first sheet 301 with multiple panels. [Figure 65] Figure 65 is a perspective view showing one of the shapes 310 formed on the multi-faceted first sheet 301. [Figure 66] Figure 66 is a plan view showing one of the shapes 310 formed on the multi-faceted first sheet 301. [Figure 67] Figure 67 is a cross-sectional view showing one of the shapes 310 formed on the multi-faceted first sheet 301. [Figure 68] Figure 68 is an enlarged view of a portion of Figure 67. [Figure 69] Figure 69 is another cross-sectional view showing one of the shapes 310 formed on the multi-panel first sheet 301. [Figure 70] Figure 70 is a plan view of the outer peripheral fluid flow channel section 314, with a portion of it enlarged. [Figure 71] Figure 71 is a cross-sectional view focusing on one of the inner liquid flow channels 315. [Figure 72]Figure 72 is a plan view of the inner liquid flow channel 315, with a portion of it enlarged. [Figure 73] Figure 73 is a diagram illustrating the joining process. [Figure 74] Figure 74 illustrates a sheet 350 with multiple intermediates attached, and a roll 351 on which the sheet with multiple intermediates attached is wound. [Figure 75] Figure 75 shows a portion of the cross-section of sheet 350 with multiple intermediates attached. [Figure 76] Figure 76 is a perspective view of intermediate 352. [Figure 77] Figure 77 is a plan view of the intermediate body 352. [Figure 78] Figure 78 illustrates the formation of the injection port 319. [Figure 79] Figure 79 illustrates the formation of the injection port 319. [Figure 80] Figure 80 illustrates the formation of other injection ports 319. [Figure 81] Figure 81 illustrates the formation of other injection ports 319. [Figure 82] Figure 82 is a perspective view of the vapor chamber 353. [Figure 83] Figure 83 is a plan view of the vapor chamber 353. [Figure 84] Figure 84 is a cross-sectional view of the vapor chamber 353. [Figure 85] Figure 85 illustrates a vapor chamber 353 in another configuration. [Figure 86] Figure 86 illustrates a vapor chamber 353 in another configuration. [Figure 87] Figure 87 illustrates a vapor chamber 353 in another configuration. [Modes for carrying out the invention]

[0011] The following description of this disclosure is based on the embodiments shown in the drawings. For clarity, the sizes and proportions of components in the following drawings may be altered or exaggerated. Furthermore, for ease of viewing, unnecessary parts and repetitive reference numerals may be omitted.

[0012] [First form] Figure 1 shows an external perspective view of the vapor chamber 1 according to the first embodiment, and Figure 2 shows an exploded perspective view of the vapor chamber 1. For convenience, arrows (x, y, z) indicating direction are also shown in these figures and in the figures shown below as needed. The xy direction is the direction of the plate surface of the flat vapor chamber 1, and the z direction is the thickness direction.

[0013] As can be seen in Figures 1 and 2, the vapor chamber 1 has a first sheet 10 and a second sheet 20. As will be explained later, the first sheet 10 and the second sheet 20 are overlapped and joined (diffusion bonding, brazing, etc.), creating a hollow space between the first sheet 10 and the second sheet 20. The working fluid is sealed in this space, creating a sealed space 2 (see, for example, Figure 19).

[0014] In this embodiment, the first sheet 10 is a sheet-like component as a whole. Figure 3 shows a perspective view of the first sheet 10 as seen from the inner surface 10a side, and Figure 4 shows a plan view of the first sheet 10 as seen from the inner surface 10a side. Figure 5 shows the cross-section of the first sheet 10 when cut along I1-I1 as shown in Figure 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 that connects the inner surface 10a and the outer surface 10b to form a thickness, and a pattern for a flow channel for the working fluid to recirculate is formed on the inner surface 10a side. As will be described later, the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20 are overlapped so as to face each other to form a hollow space, into which the working fluid is sealed to form a sealed space 2.

[0015] As can be seen from Figure 5, in this embodiment, the first sheet 10 is composed of 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 made up of multiple layers stacked together, with one of the layers forming the inner surface 10a and the other layers forming the outer surface 10b. In this embodiment, the side surface 10c is formed by the end face of the inner layer 10d and the end face of the outer layer 10e.

[0016] Here, as described above, a pattern for the movement of the working fluid is provided on the inner surface 10a side of the first sheet 10, and the inner layer 10d constitutes the surface of this pattern that the working fluid directly contacts. For this reason, it is preferable that the inner layer 10d be 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 the reaction with the working fluid (especially water), and furthermore, as will be described later, it becomes easier to manufacture the vapor chamber.

[0017] The outer layer 10e is formed by laminating the inner layer 10d on the inner surface 10a side and forming the outer surface 10b. The outer layer 10e, on the side in contact with the inner layer 10d, is provided with a pattern formed on the inner surface 10a of the first sheet 10. However, as described above, although this patterned portion of the outer layer 10e forms a flow path, it is covered by the inner layer 10d so that the working fluid does not come into direct contact with it. In other words, grooves are formed in the outer layer 10e that serve as flow paths for the working fluid (condensate flow path and vapor flow path), and the inner layer 10d is laminated inside these grooves.

[0018] On the other hand, in this embodiment, the outer surface 10b of the outer layer 10e is a flat surface or a slightly uneven surface, etc., which is designed to take into consideration contact with the components placed in the vapor chamber 1. Therefore, in this embodiment, the outer layer 10e is configured such that the distance (i.e., thickness) between the surface that contacts the inner layer 10d on the inner surface 10a side and the outer surface 10b differs 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 when thinned while forming a flow path.

[0019] Therefore, it is preferable that the outer layer 10e is made of a material with higher strength than the inner layer 10d. Specifically, it is preferable that the 0.2% proof stress or upper yield point of the outer layer 10e is greater than that of the inner layer 10d. As long as this condition is met, there are no particular limitations, but for higher strength, it is preferable that the 0.2% proof stress or upper yield point of the outer layer 10e be 100 MPa or more, and more preferably 200 MPa or more. This allows for the formation of desired flow paths in the vapor chamber, while also suppressing deformation and damage to the vapor chamber against external impacts, expansion due to solidification of the working fluid due to low-temperature freezing, and forces such as vapor pressure during operation, even when the chamber is made thinner. Furthermore, because the outer layer 10e improves the strength of the vapor chamber in this way, the constraints on strength regarding the flow path pattern formed on the inner surface 10a side for the working fluid can be relaxed, and a design that focuses on improving thermal performance becomes possible, thus offering advantages from the standpoint of thermal performance as well.

[0020] The material constituting the outer layer 10e is not particularly limited, but from the viewpoint of heat diffusion, a high thermal conductivity is preferable, and it is preferable that it is 10 W / m·K or higher. From this viewpoint, examples of materials constituting the outer layer 10e include iron-based materials such as stainless steel, invar, and Kovar, titanium alloys, and nickel alloys. Furthermore, composite materials containing fine particles of diamond, alumina, silicon carbide, etc., in addition to these metals may be used.

[0021] The thickness of the inner layer 10d is not particularly limited, taking the specifications into consideration, but it is preferably between 5 μm and 20 μm. If the inner layer 10d is thinner than 5 μm, the likelihood of mutual influence between the outer layer 10e material and the working fluid increases. On the other hand, if the inner layer 10d is thicker than 20 μm, difficulties may arise from a manufacturing standpoint, making it difficult to meet the required thickness specifications, including in-plane variation, and increasing the likelihood of a rough surface.

[0022] On the other hand, the thickness of the outer layer 10e is not particularly limited as it depends on the specifications, but it is preferable that it be between 0.02 mm and 0.5 mm in all parts. If there are parts of the outer layer 10e that are thinner than 0.02 mm, the effect of suppressing deformation may be reduced, and if there are parts that are thicker than 0.5 mm, heat transfer from the vapor chamber to the outside may be hindered, or it may become difficult to meet the thickness specifications.

[0023] 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, 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, may be 0.05 mm or more, or 0.1 mm or more. This thickness range may be determined by any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, this thickness range may be determined by any two combinations of the above-mentioned upper limit candidate values, or any two combinations of the above-mentioned lower limit candidate values. This expands the range of applications for thin vapor chambers. Furthermore, even when the desired flow path is formed in the vapor chamber while making it thin, deformation and damage to the vapor chamber can be suppressed against external impacts, expansion due to solidification of the working fluid due to low-temperature freezing, and forces such as vapor pressure during operation.

[0024] Such a first sheet 10 comprises a main body 11 and an injection section 12. The main body 11 is a sheet that forms the portion through which the working fluid recirculates, and in this embodiment, it is a rectangle with arc-shaped corners (so-called R) in a plan view. As described above, the inner surface 10a of the main body 11 and the injection section 12 consists of an inner layer 10d, and the outer surface 10b consists of an outer layer 10e.

[0025] The injection section 12 is the part into which 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 rectangular sheet in plan view that protrudes from one side of the main body 11, which is rectangular in plan view. In this embodiment, both the inner surface 10a and the outer surface 10b of the injection section 12 of the first sheet 10 are flat surfaces.

[0026] A structure for the recirculation of the working fluid is formed on the inner surface 10a side of the main body 11. The main body 11 is rectangular as in this embodiment, but may also be circular, elliptical, triangular, other polygons, or have a bent portion, such as an L-shape, T-shape, or crank shape. It can also be a combination of at least two of these shapes. The main body 11 is configured with an outer peripheral joint portion 13, an outer peripheral liquid flow path portion 14, an inner liquid flow path portion 15, a steam flow path groove 16, and a steam flow path communication groove 17 on its inner surface 10a side.

[0027] The outer peripheral joint portion 13 is a surface formed on the inner surface 10a side of the main body 11, along the outer circumference of the main body 11. When this outer peripheral joint portion 13 overlaps with the outer peripheral joint portion 23 of the second sheet 20 and is joined (diffusion bonding, brazing, etc.), a hollow portion is formed between the first sheet 10 and the second sheet 20, and a working fluid is sealed in this space to form a sealed space 2. The width of the outer peripheral joint 13, indicated by W1 in Figures 4 and 5 (the width at the joint surface with the second sheet 20, measured in the direction perpendicular to the direction in which the outer peripheral joint 13 extends), can be set as appropriate as needed. However, this width W1 is preferably 3.0 mm or less, may be 2.5 mm or less, or 2.0 mm or less. If the width W1 is greater than 3 mm, the internal volume of the sealed space will decrease, and there is a risk that sufficient steam flow paths and condensate flow paths will not be secured. On the other hand, the width W1 is preferably 0.2 mm or more, may be 0.6 mm or more, or 0.8 mm or more. If the width W1 is less than 0.2 mm, there is a risk that the joint area will be insufficient when misalignment 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 above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of the width W1 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values.

[0028] Furthermore, holes 13a that penetrate in the thickness direction (z direction) are provided at the four corners of the main body 11 within the outer peripheral joint portion 13. These holes 13a function as positioning means when overlapping with the second sheet 20.

[0029] The outer peripheral fluid channel section 14 functions as a fluid channel and constitutes a part of the condensed fluid channel 3, which is the second channel through which the working fluid passes when it condenses and liquefies. Figure 6 shows the portion indicated by arrow I2 in Figure 5, and Figure 7 shows the cross-section of the portion cut by I3-I3 in Figure 4. Both figures show the cross-sectional shape of the outer peripheral fluid channel section 14. Figure 8 shows an enlarged plan view of the outer peripheral fluid channel section 14 as seen from the direction indicated by arrow I4 in Figure 6.

[0030] As can be seen from these figures, the outer peripheral fluid channel section 14 is formed along the inner surface 10a of the main body 11, along the inside of the outer peripheral joint section 13, and is provided along the outer circumference of the sealed space 2. In addition, the outer peripheral fluid channel section 14 has multiple fluid channel grooves 14a that extend parallel to the outer peripheral direction of the main body 11, and the multiple fluid channel grooves 14a are arranged at predetermined intervals in a direction different from the direction in which the fluid channel grooves 14a extend. Therefore, as can be seen from Figures 6 and 7, in the cross-section of the outer peripheral fluid channel section 14, on the inner surface 10a side, the recessed fluid channel grooves 14a and the convex portions 14b between the fluid channel grooves 14a are formed in an uneven pattern. Furthermore, this liquid flow channel groove 14a is a groove formed by stacking the inner layer 10d inside a groove formed in the outer layer 10e.

[0031] By providing multiple liquid flow channel grooves 14a in this manner, the depth and width of each individual liquid flow channel groove 14a can be reduced, thereby reducing the cross-sectional area of ​​the second flow channel, the condensate flow channel 3 (see Figure 20, etc.), and enabling the use of large capillary forces. On the other hand, by having multiple liquid flow channel grooves 14a, the total cross-sectional area of ​​the condensate flow channel 3 can be increased to a suitable size, allowing the required flow rate of condensate to be transmitted.

[0032] Since the liquid flow channel groove 14a is a groove, its cross-sectional shape includes a bottom portion on the outer surface 10b side and an opening on the inner surface 10a side opposite to the bottom portion. In this embodiment, the liquid flow channel groove 14a has a semi-elliptical cross-section. However, the cross-sectional shape is not limited to a semi-elliptical shape; it may be a circle, a rectangle, a square, a trapezoid or other quadrilateral, other polygons, or a combination of any or more of these shapes.

[0033] Furthermore, in this embodiment, as can be seen in Figure 8, adjacent liquid flow channels 14a in the outer peripheral liquid flow channel section 14 are connected by communication openings 14c at predetermined intervals. This promotes the equalization of the amount of condensed liquid among the multiple liquid flow channels 14a, allowing the condensed liquid to flow efficiently and enabling smooth recirculation of the working fluid. In this embodiment, as shown in Figure 8, the communication openings 14c are arranged opposite each other at the same position in the direction in which the liquid flow channel groove 14a extends, flanking the groove. However, this is not the only option, and for example, as shown in Figure 9, the communication openings 14c may be arranged at different positions in the direction in which the liquid flow channel groove 14a extends, flanking the groove. That is, the protrusions 14b and communication openings 14c may be arranged alternately along a direction perpendicular to the direction in which the liquid flow channel groove extends.

[0034] Other configurations are also possible, such as those shown in Figures 10 to 12. Figures 10 to 12 show, from the same viewpoint as Figure 8, a single condensate flow path 14a, two protrusions 14b flanking it, and a single communication opening 14c provided in each protrusion 14b. In all of these configurations, the shape of the protrusions 14b and the communication opening 14c from this viewpoint (plan view) differs from the example in Figure 8. In other words, in the convex portion 14b shown in Figure 8, the width is the same and constant as the other parts even at the end where the communication opening 14c is formed. In contrast, in the convex portion 14b shapes shown in Figures 10 to 12, the width at the end where the communication opening 14c is formed is smaller than the maximum width of the convex portion 14b. More specifically, in the example in Figure 10, the corner at the end is arc-shaped and a radius is formed at the corner, which reduces the width of the end; in Figure 11, the end is semi-circular, which reduces the width of the end; and in Figure 12, the end tapers to a point.

[0035] As shown in Figures 10 to 12, the width of the communication opening 14c at the end of the protrusion 14b is formed to be smaller than the maximum width of the protrusion 14b, which facilitates the movement of the working fluid through the communication opening 14c and facilitates the movement of the working fluid to the adjacent condensate flow path 3.

[0036] The outer peripheral fluid flow channel section 14 having the above configuration is preferably further configured as follows. The width of the outer peripheral liquid flow channel section 14, indicated by W2 in Figures 4 to 7 (the width at the joint surface with the second sheet 20, measured in the direction in which the liquid flow channel grooves 14a are arranged), can be appropriately set based on the overall size of the vapor chamber, etc. However, the width W2 is preferably 3.0 mm or less, may be 1.5 mm or less, or 1.0 mm or less. If the width W2 exceeds 3.0 mm, there is a risk that sufficient space will not be available for the inner liquid flow channel and vapor flow channel. On the other hand, the width W2 is preferably 0.1 mm or more, may be 0.2 mm or more, or 0.4 mm or more. If the width W2 is less than 0.1 mm, there is a risk that a sufficient amount of liquid will not be recirculated on the outside. The range of the width W2 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of the width W2 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. The width W2 may be the same as the width W9 of the outer peripheral liquid flow channel 24 of the second sheet 20 (see Figure 17), or it may be larger or smaller. In this embodiment, they are the same.

[0037] Regarding the liquid flow channel groove 14a, the groove width (size in the direction in which the liquid flow channel grooves 14a are arranged, width at the opening surface of the groove), indicated by W3 in Figures 6 and 8, is preferably 1000 μm or less, 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, 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 above-mentioned upper limit candidate values ​​and one of the multiple lower limit candidate values. Furthermore, the range of the width W3 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 groove depth indicated by D1 in Figures 6 and 7 is preferably 200 μm or less, but may be 150 μm or less, or 100 μm or less. On the other hand, the depth D1 is preferably 5 μm or more, but may be 10 μm or more, or 20 μm or more. The range of depth D1 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of depth D1 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. By configuring it as described above, the capillary force of the condensate flow path necessary for reflux can be exerted more strongly.

[0038] From the viewpoint of exerting stronger capillary action in the condensate flow path, the aspect ratio (length-to-width ratio) of the flow path cross-section, which is expressed as the width W3 divided by the depth D1, is preferably greater than 1.0. This ratio may be 1.5 or greater, or 2.0 or greater. Alternatively, the aspect ratio may be less than 1.0. This ratio may be 0.75 or less, or 0.5 or less. From a manufacturing standpoint, it is preferable that W3 be greater than D1, and from this standpoint, it is preferable that the aspect ratio be greater than 1.3.

[0039] Furthermore, the pitch between adjacent liquid flow channels 14a in the multiple liquid flow channels 14a is preferably 1100 μm or less, may be 550 μm or less, or 220 μm or less. On the other hand, the pitch is preferably 30 μm or more, may be 55 μm or more, or 70 μm or more. This pitch range may be determined by a combination of any one of the above multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Alternatively, 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 allows for an increase in the density of the condensate flow path while suppressing deformation and collapse of the condensate flow path during joining or assembly.

[0040] Regarding the communication opening 14c, the size of the opening along the direction in which the liquid flow channel groove 14a, indicated by L1 in Figure 8, extends is preferably 1100 μm or less, but may be 550 μm or less, or 220 μm or less. On the other hand, the size L1 is preferably 30 μm or more, but may be 55 μm or more, or 70 μm or more. The range of size L1 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, the range of size L1 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values.

[0041] Furthermore, the pitch of adjacent communication openings 14c in the direction in which the liquid flow channel groove 14a, indicated by L2 in Figure 8, extends is preferably 2700 μm or less, but may be 1800 μm or less, or 900 μm or less. On the other hand, this pitch L2 is preferably 60 μm or more, but may be 110 μm or more, or 140 μm or more. The range of this pitch L2 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of pitch L2 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values.

[0042] Let's return to Figures 1-5 and explain the inner liquid flow channel 15. The inner liquid flow channel 15 also functions as a liquid flow channel and is part of the condensed liquid flow channel 3, which is the second flow channel through which the working fluid passes when it condenses and liquefies. Figure 13 shows the part indicated by I4 in Figure 5. The cross-sectional shape of the inner liquid flow channel 15 is also shown in this figure. Figure 14 shows an enlarged plan view of the inner liquid flow channel 15 as seen from the direction indicated by arrow I5 in Figure 13.

[0043] As can be seen from these figures, the inner liquid flow channel section 15 is a wall formed on the inner surface 10a of the main body 11, inside the ring-shaped outer liquid flow channel section 14. In this embodiment, the inner liquid flow channel section 15 is a wall that extends in the direction parallel to the long side (x direction) of the rectangular main body 11 in plan view, and multiple (three in this embodiment) inner liquid flow channel sections 15 are arranged at predetermined intervals in the direction parallel to the short side (y direction). Each inner liquid channel section 15 has a liquid channel groove 15a formed parallel to the direction in which the inner liquid channel section 15 extends, and multiple liquid channel grooves 15a are arranged at predetermined intervals in a direction different from the direction in which the liquid channel grooves 15a extend. Therefore, as can be seen from Figures 5 and 13, in the cross-section of the inner liquid channel section 15, the inner surface 10a side has a repeating pattern of recessed liquid channel grooves 15a and protrusions 15b between the liquid channel grooves 15a. Note that this liquid channel groove 15a is a groove formed by laminating the inner layer 10d inside a groove formed in the outer layer 10e.

[0044] By providing multiple liquid flow channel grooves 15a in this manner, the depth and width of each individual liquid flow channel groove 15a can be reduced, thereby reducing the cross-sectional area of ​​the condensate flow channel 3 (see Figure 20, etc.) as the second flow channel and enabling the use of large capillary forces. On the other hand, by having multiple liquid flow channel grooves 15a, the total cross-sectional area of ​​the condensate flow channel 3 can be increased to a suitable size, allowing the required flow rate of condensate to be transmitted.

[0045] Since the liquid flow channel groove 15a is a groove, its cross-sectional shape includes a bottom portion on the outer surface 10b side and an opening on the inner surface 10a side at the opposite end opposite the bottom portion. In this embodiment, the liquid flow channel groove 15a has a semi-elliptical cross-section. However, the cross-sectional shape is not limited to a semi-elliptical shape; it may be a circle, a rectangle, a square, a trapezoid or other quadrilateral, other polygons, or a combination of any several of these shapes.

[0046] Furthermore, as can be seen in Figure 14, adjacent liquid flow channel grooves 15a are connected by communication openings 15c at predetermined intervals. This promotes the equalization of the condensate volume among multiple liquid flow channel grooves 15a, allowing the condensate to flow efficiently and thus enabling smooth recirculation of the working fluid. Similar to the communication opening 14c, the convex portion 15b and the communication opening 15c may be alternately arranged along a direction perpendicular to the direction in which the liquid flow channel groove 15a extends, following the example shown in Figure 9. Alternatively, the shapes of the communication opening 15c and the convex portion 15b may be as shown in the examples in Figures 10 to 12.

[0047] The inner liquid flow channel section 15 having the above configuration is preferably further equipped with the following configuration. The width of the inner liquid flow channel section 15, indicated by W4 in Figures 4, 5, and 13 (the width at the joint surface with the second sheet 20, measured in the direction in which the inner liquid flow channel section 15 and the steam flow channel groove 16 are aligned), is preferably 3000 μm or less, may be 1500 μm or less, or 1000 μm or less. On the other hand, this width W4 is preferably 100 μm or more, may be 200 μm or more, or 400 μm or more. The range of this width W4 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, the range of width G may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. The width W4 is the width W of the inner liquid flow channel section 25 of the second sheet. 10 It may be the same as (see Figure 17), or it may be larger or smaller. In this embodiment, they are considered to be the same.

[0048] Furthermore, the pitch of the multiple inner liquid flow channels 15 is preferably 4000 μm or less, but may be 3000 μm or less, or 2000 μm or less. On the other hand, this pitch is preferably 200 μm or more, but may be 400 μm or more, or 800 μm or more. This pitch range may be determined by a combination of any one of the above multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Alternatively, 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 channel, allowing for a good balance between steam movement and condensate reflux.

[0049] Regarding the liquid flow channel groove 15a, the groove width (size in the direction in which the liquid flow channel grooves 15a are arranged, and the width at the opening surface of the groove), indicated by W5 in Figures 13 and 14, is preferably 1000 μm or less, may be 500 μm or less, or 200 μm or less. On the other hand, this width W5 is preferably 20 μm or more, may be 45 μm or more, or 60 μm or more. The range of this width W5 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, the range of width W5 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. Furthermore, the groove depth indicated by D2 in Figure 13 is preferably 200 μm or less, but may be 150 μm or less, or 100 μm or less. On the other hand, this depth D2 is preferably 5 μm or more, but may be 10 μm or more, or 20 μm or more. The range of this depth D2 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of depth D2 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. This allows the capillary action of the condensate flow path, which is necessary for reflux, to be strongly exerted.

[0050] From the viewpoint of maximizing the capillary action of the flow path, the aspect ratio (length-to-width ratio) of the flow path cross-section, which is expressed as the width W5 divided by the depth D2, is preferably greater than 1.0. It may be 1.5 or greater, or 2.0 or greater. Alternatively, it may be less than 1.0, or 0.75 or less, or 0.5 or less. From a manufacturing standpoint, it is preferable that the width W5 is greater than the depth D2, and from this standpoint, it is preferable that the aspect ratio is greater than 1.3.

[0051] Furthermore, the pitch between adjacent liquid flow channels 15a in the multiple liquid flow channels 15a is preferably 1100 μm or less, may be 550 μm or less, or 220 μm or less. On the other hand, this pitch is preferably 30 μm or more, may be 55 μm or more, or 70 μm or more. This pitch range may be determined by a combination of any one of the above multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Alternatively, 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 allows for an increase in the density of the condensate flow path while suppressing deformation and collapse of the flow path during joining or assembly.

[0052] Furthermore, with respect to the communication opening 15c, the size of the opening along the direction in which the liquid flow channel groove 15a, indicated by L3 in Figure 14, extends is preferably 1100 μm or less, but may also be 550 μm or less, or 220 μm or less. On the other hand, this size L3 is preferably 30 μm or more, but may also be 55 μm or more, or 70 μm or more. The range of this size L3 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of size L3 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. Furthermore, the pitch of adjacent communication openings 15c in the direction in which the liquid flow channel groove 15a extends, as indicated by L4 in Figure 14, is preferably 2700 μm or less, but may be 1800 μm or less, or 900 μm or less. On the other hand, this pitch L4 is preferably 60 μm or more, but may be 110 μm or more, or 140 μm or more. The range of this pitch L4 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of this pitch L4 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values.

[0053] In the above-described embodiment, the liquid flow channels 14a and 15a are spaced equally apart and arranged parallel to each other, but this is not the only way to do so. The pitch between the channels may vary as long as capillary action can be achieved, and the channels do not have to be parallel to each other.

[0054] Next, the steam channel groove 16 will be described. The steam channel groove 16 is the part through which the vaporized steam from the evaporation of the working fluid passes, and it constitutes a part of the first channel, the steam channel 4 (see Figure 19, etc.). Figure 4 shows the shape of the steam channel groove 16 in plan view, and Figure 5 shows the cross-sectional shape of the steam channel groove 16.

[0055] As can be seen from these figures, the steam channel groove 16 is composed of a groove formed on the inner surface 10a of the main body 11, inside the ring that is an annular part of the outer peripheral liquid channel section 14. More specifically, the steam channel groove 16 in this embodiment is formed between adjacent inner liquid channel sections 15, and between the outer peripheral liquid channel section 14 and the inner liquid channel section 15, and is a groove that extends in the direction parallel to the long side (x direction) of the rectangle in plan view of the main body 11. Multiple (four in this embodiment) steam channel grooves 16 are arranged in the direction parallel to the short side (y direction). Therefore, as can be seen from Figure 5, the first sheet 10 has a shape in the y direction in which the walls of the outer peripheral liquid channel section 14 and the inner liquid channel section 15 are convex, and the steam channel groove 16 are concave, with repeated concave and concave shapes. Since the steam flow channel groove 16 is a groove, its cross-sectional shape has a bottom that faces the outer surface 10b, and an opening on the opposite side of the bottom that faces the inner surface 10a. Furthermore, this steam flow channel groove 16 is a groove formed in the outer layer 10e, with the inner layer 10d laminated inside it.

[0056] A steam channel groove 16 having such a configuration is preferably further provided with the following configuration. The width of the steam channel groove 16, indicated by W6 in Figures 4 and 5 (the width at the opening surface of the groove, measured in the direction in which the inner liquid channel section 15 and the steam channel groove 16 are aligned), is formed to be at least larger than the width W3 of the liquid channel groove 14a and the width W5 of the liquid channel groove 15a, and is preferably 2000 μm or less, but may be 1500 μm or less, or 1000 μm or less. On the other hand, this width W6 is preferably 100 μm or more, may be 200 μm or more, or 400 μm or more. The range of this width W6 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, the range of width W6 may be determined by any two combinations of the above-mentioned upper limit candidate values, or by the above-mentioned lower limit It may also be determined by any two combinations of candidate values. The pitch of the steam channel groove 16 is usually determined by the pitch of the inner liquid channel section 15. On the other hand, the depth of the steam channel groove 16, indicated by D3 in Figure 5, is formed to be at least greater than the depth D1 of the liquid channel groove 14a and the depth D2 of the liquid channel groove 15a, and is preferably 300 μm or less, but may be 200 μm or less, or 100 μm or less. On the other hand, this depth D3 is preferably 10 μm or more, may be 25 μm or more, or 50 μm or more. The range of this depth D3 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, the range of depth D3 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. In this way, by making the cross-sectional area of ​​the steam channel groove larger than that of the liquid channel groove, steam, which has a larger volume than the condensate due to the properties of the working fluid, can be smoothly recirculated.

[0057] In this embodiment, the cross-sectional shape of the steam channel groove 16 is semi-elliptical, but it is not limited to this and may be rectangular, square, trapezoidal or other quadrilateral, triangular, semicircular, with a semicircular base, with a semi-elliptical base, or a combination of any of these shapes. The steam channel can reduce the flow resistance of the steam, thereby enabling smooth recirculation of the working fluid, so the shape of the channel cross-section can also be determined from this perspective.

[0058] In this embodiment, an example has been described in which one steam channel groove 16 is formed between adjacent inner liquid channel sections 15. However, the embodiment is not limited to this, and two or more steam channel grooves may be arranged side by side between adjacent inner liquid channel sections. Furthermore, if steam channel grooves are formed in the second sheet 20, the first sheet 10 may be configured in such a way that steam channel grooves are not formed in part or all of it.

[0059] The steam flow channel connecting groove 17 is a groove that connects multiple steam flow channel grooves 16. This allows for the equalization of steam within the multiple steam flow channel grooves 16, and enables the steam to be transported over a wider area, allowing for the efficient use of many condensate flow channels 3, thereby making the recirculation of the working fluid smoother.

[0060] As can be seen in Figures 3 and 4, the steam flow channel connecting groove 17 in this embodiment is formed between the inner liquid flow channel section 15, the ends in the direction in which the steam flow channel groove 16 extends, and the outer liquid flow channel section 14. Figure 7 also shows a cross-section perpendicular to the communication direction of the steam flow channel connecting groove 17, along the line indicated by I3-I3 in Figure 4. In Figures 2 to 4, dotted lines have been added to the areas that should represent the boundary between the steam flow channel groove 16 and the steam flow channel connecting groove 17 for clarity. However, these lines are not necessarily lines that appear due to the actual shape, but are hypothetical lines added for clarity.

[0061] The steam flow channel connecting groove 17 only needs to be formed to connect adjacent steam flow channel grooves 16, and its shape is not particularly limited, but it can have the following configuration, for example. The width of the steam flow channel communication groove 17, indicated by W7 in Figures 4 and 7 (measured in the direction perpendicular to the communication direction, and the width at the opening surface of the groove), is preferably 1000 μm or less, may be 750 μm or less, or 500 μm or less. On the other hand, this width W7 is preferably 100 μm or more, may be 150 μm or more, or 200 μm or more. The range of this width W7 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, the range of the width W7 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. Furthermore, the depth of the steam flow channel communication groove 17, indicated by D4 in Figure 7, is preferably 300 μm or less, but may be 225 μm or less, or 150 μm or less. On the other hand, this depth D4 is preferably 10 μm or more, but may be 25 μm or more, or 50 μm or more. The range of this depth D4 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of depth D4 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values.

[0062] In this embodiment, the cross-sectional shape of the steam flow channel connecting groove 17 is semi-elliptical, but it is not limited to this, and may be rectangular, square, trapezoidal or other quadrilateral, triangular, semicircular, with a semicircular base, with a semi-elliptical base, or any combination of any of these. Since the steam flow channel connecting groove can reduce the flow resistance of steam, thereby enabling smooth recirculation of the working fluid, the shape of the channel cross-section can also be determined from this perspective. This steam flow channel connecting groove 17 is also a groove consisting of a groove provided in the outer layer 10e and an inner layer 10d laminated inside this groove.

[0063] In this embodiment, the outer surface 10b of the main body 11 is configured to be a flat surface. This improves adhesion to members that should be in close contact with the outer surface 10b (for example, electronic components to be cooled, or the housing of electronic equipment to which heat should be transferred). 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 rather a shape that allows the outer surface 10b to contribute to the intended heat transfer, etc. Furthermore, as described above, this outer surface 10b is formed by the outer layer 10e. Consequently, the thickness of the outer layer 10e differs depending on the position in the x direction and the y direction. With such an inner surface 10a, an outer surface 10b, and the inner layer 10d and outer layer 10e constituting them, even when the vapor chamber is made thinner while forming the desired flow path, deformation and damage to the vapor chamber can be suppressed against external impacts, expansion due to solidification of the working fluid due to low-temperature freezing, and forces such as vapor pressure during operation.

[0064] Next, the second sheet 20 will be described. In this embodiment, the second sheet 20 is also a sheet-like component as a whole. Figure 15 shows a perspective view of the second sheet 20 as seen from the inner surface 20a side, and Figure 16 shows a plan view of the second sheet 20 as seen from the inner surface 20a side. Figure 17 shows the cross-section of the second sheet 20 when cut along I6-I6 as in Figure 16. Figure 18 shows the cross-section of the second sheet 20 when cut along I7-I7 as in Figure 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 that connects the inner surface 20a and the outer surface 20b to form a thickness, and a pattern is formed on the inner surface 20a side for the working fluid to recirculate. As will be described later, a hollow space is formed when the inner surface 20a of the second sheet 20 and the inner surface 10a of the first sheet 10 are superimposed so that they face each other, and a sealed space 2 is formed by sealing the working fluid in this space.

[0065] As can be seen from Figures 16 and 17, in this embodiment, the second sheet 20 is composed of 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 made up of multiple layers stacked together, with one of the layers forming the inner surface 20a and the other layers forming the outer surface 20b. In this embodiment, the side surface 20c is formed by the end face of the inner layer 20d and the end face of the outer layer 20e.

[0066] Here, the inner surface 20a of the second sheet 20 is provided with a pattern for the movement of the working fluid, and the inner layer 20d constitutes the surface of this pattern that the working fluid directly contacts. Therefore, it is preferable that the inner layer 20d be made of a material that is chemically stable with respect to the working fluid and has high thermal conductivity. 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 the reaction with the working fluid (especially water), and furthermore, it becomes easier to fabricate a vapor chamber by etching and diffusion bonding as described later.

[0067] The outer layer 20e is formed by laminating the inner layer 20d on the inner surface 20a side and also forming the outer surface 20b. The outer layer 20e, on the side in contact with the inner layer 20d, is provided with a pattern formed on the inner surface 20a of the second sheet 20. However, as described above, although this patterned portion of the outer layer 20e forms a flow path, it is covered by the inner layer 20d so that the working fluid does not come into direct contact with it. In other words, the outer layer 20e has grooves that serve as flow paths, and the inner layer 20d is laminated inside these grooves.

[0068] On the other hand, in this embodiment, the outer surface 20b of the outer layer 20e is designed to be a flat surface or a slightly uneven surface, taking into consideration contact with the components placed in the vapor chamber 1. Therefore, in this embodiment, the outer layer 20e is configured such that the distance (i.e., thickness) between the surface that contacts the inner layer 20d on the inner surface 20a side and the outer surface 20b differs depending on the position in the x direction and the position in the y direction. This allows a vapor chamber that is thin while still forming a flow path to possess the necessary strength to function as a vapor chamber.

[0069] Therefore, it is preferable that the outer layer 20e is made of a material with higher strength than the inner layer 20d. Specifically, it is preferable that the 0.2% proof stress or upper yield point of the outer layer 20e is greater than that of the inner layer 20d. As long as this condition is met, there are no particular limitations, but for higher strength, the 0.2% proof stress 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 suppress deformation and damage to the vapor chamber against external impacts, expansion due to solidification of the working fluid due to low-temperature freezing, and forces such as vapor pressure during operation, even when the desired flow path is formed in the vapor chamber while making it thinner. Furthermore, because the outer layer 20e improves the strength of the vapor chamber in this way, the constraints on strength regarding the flow path pattern formed on the inner surface 20a side for the working fluid can be relaxed, and a design that focuses on improving thermal performance becomes possible, thus offering advantages from a thermal performance standpoint as well.

[0070] The material constituting the outer layer 20e is not particularly limited, but from the viewpoint of heat diffusion, a high thermal conductivity is preferable, preferably 10 W / m·K or higher. From this viewpoint, examples of materials constituting the outer layer 20e include iron-based materials such as stainless steel, invar, and Kovar, titanium alloys, and nickel alloys. Furthermore, composite materials containing fine particles of diamond, alumina, silicon carbide, etc., in addition to these metals may be used.

[0071] The thickness of the inner layer 20d is not particularly limited, taking into consideration the specifications, but it is preferably between 5 μm and 20 μm. If the inner layer 20d is thinner than 5 μm, the likelihood of mutual influence between the outer layer 20e material and the working fluid increases. On the other hand, if the inner layer 20d is thicker than 20 μm, difficulties may arise from a manufacturing standpoint, it may become difficult to meet the required thickness specifications, including in-plane variation, and the surface may become rougher.

[0072] On the other hand, the thickness of the outer layer 20e is not particularly limited as it depends on the specifications, but it is preferable that it be between 0.02 mm and 0.5 mm in all parts. If there are parts of the outer layer 20e that are thinner than 0.02 mm, the effect of suppressing deformation may be reduced, and if there are parts that are thicker than 0.5 mm, heat transfer from the vapor chamber to the outside may be hindered or it may become difficult to meet the thickness specifications.

[0073] 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, 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, may be 0.05 mm or more, or 0.1 mm or more. This thickness range may be determined by any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, this thickness range may be determined by any two combinations of the above-mentioned upper limit candidate values, or any two combinations of the above-mentioned lower limit candidate values. This expands the range of applications for thin vapor chambers. Furthermore, even when the desired flow path is formed in the vapor chamber while making it thin, deformation and damage to the vapor chamber can be suppressed against external impacts, expansion due to solidification of the working fluid due to low-temperature freezing, and forces such as vapor pressure during operation. Furthermore, the thickness of the first sheet 10 and the second sheet 20 may be the same or different.

[0074] Such a second sheet 20 comprises a main body 21 and an injection section 22. The main body 21 is a sheet-like portion that forms the area through which the working fluid recirculates, and in this embodiment, it is a rectangle with circular arcs (so-called R) formed at its corners in a plan view. However, the main body 21 of the second sheet 20 may be rectangular as in this embodiment, or it may be circular, elliptical, triangular, or other polygonal, or it may have a bent portion, such as an L-shape, T-shape, or crank shape. It may also be a combination of at least two of these shapes.

[0075] The injection section 22 is the part into which working fluid is injected into the hollow section formed by the first sheet 10 and the second sheet 20 to create a sealed space 2 (see Figure 19). In this embodiment, it is a rectangular sheet in plan view that protrudes from one side of the main body 21, which 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 outside and inside (hollow section, the part that will become the sealed space 2) of the main body 21 are in communication from the side surface 20c of the second sheet 20.

[0076] A structure for the recirculation of the working fluid is formed on the inner surface 20a side of the main body 21. Specifically, the inner surface 20a side of the main body 21 is provided with an outer peripheral joint 23, an outer peripheral liquid flow channel 24, an inner liquid flow channel 25, a steam flow channel groove 26, and a steam flow channel connecting groove 27.

[0077] The outer peripheral joint portion 23 is a surface formed on the inner surface 20a side of the main body 21, along the outer circumference of the main body 21. When this outer peripheral joint portion 23 overlaps with the outer peripheral joint portion 13 of the first sheet 10 and is joined (diffusion bonding, brazing, etc.), a hollow portion is formed between the first sheet 10 and the second sheet 20, and the working fluid is sealed in there to form a sealed space 2. The width of the outer periphery joint 23, indicated by W8 in Figures 16 to 18 (the width at the joint surface with the first sheet 10, measured in the direction perpendicular to the direction in which the outer periphery joint 23 extends), is preferably the same as the width W1 of the outer periphery joint 13 of the main body 11 described above. However, it is not limited to this; it may be larger or smaller.

[0078] Furthermore, holes 23a that penetrate in the thickness direction (z direction) are provided at the four corners of the main body 21 within the outer peripheral joint portion 23. These holes 23a function as positioning means when overlapping with the first sheet 10.

[0079] The outer peripheral fluid channel section 24 is a fluid channel section and is a part of the condensed fluid channel 3, which is a second channel through which the working fluid passes when it condenses and liquefies.

[0080] The outer peripheral liquid channel portion 24 is formed along the inner side of the outer peripheral joint portion 23 on the inner surface 20a of the main body 21. In this embodiment, as can be seen from Figures 17 and 18, the outer peripheral liquid channel portion 24 of the second sheet 20 is a flat surface and flush with the outer peripheral joint portion 23 before joining with the first sheet 10. This closes the openings of the multiple liquid channel grooves 14a of the first sheet 10 described above, forming the condensed liquid channel 3, which is the second channel. A detailed description of the combination of the first sheet 10 and the second sheet 20 will be explained later. In this embodiment, the second sheet 20 has a flush outer periphery joint 23 and an outer periphery liquid flow channel 24, so structurally there is no boundary line to distinguish the two. However, for clarity, the boundary between the two is shown by a dotted line in Figures 15 and 16.

[0081] The outer peripheral fluid flow channel 24 preferably has the following configuration. The width of the outer peripheral liquid flow channel portion 24, indicated by W9 in Figures 16 to 18 (the width at the joint surface with the first sheet 10, measured in the direction perpendicular to the direction in which the outer peripheral liquid flow channel portion 24 extends), may be the same as the width W2 of the outer peripheral liquid flow channel portion 14 of the first sheet 10, or it may be larger or smaller.

[0082] Next, the inner liquid flow channel section 25 will be described. The inner liquid flow channel section 25 is also a liquid flow channel section and is one of the parts that make up the condensed liquid flow channel 3, which is the second flow channel.

[0083] As can be seen from Figures 15 to 18, the inner liquid flow channel section 25 is formed on the inner surface 20a of the main body 21, inside the ring that is annular to the outer liquid flow channel section 24. In this embodiment, the inner liquid flow channel section 25 is a wall that extends in the direction parallel to the long side (x direction) of the rectangular main body 21 in plan view, and multiple (three in this embodiment) inner liquid flow channel sections 25 are arranged at predetermined intervals in the direction parallel to the short side (y direction). In this embodiment, the inner surface 20a of each inner liquid channel portion 25 is formed as a flat surface before joining with the first sheet 10. This closes the openings of the multiple liquid channel grooves 15a of the first sheet 10, thereby forming the condensed liquid channel 3.

[0084] Figures 16 and 17 show W 10 The width of the inner liquid flow channel 25 (the width at the joint surface with the first sheet 10, in the direction in which the inner liquid flow channel 25 and the steam flow channel groove 26 are arranged) shown above may be the same as the width W4 of the inner liquid flow channel 15 of the first sheet 10, or it may be larger or smaller. In this embodiment, it is set to be the same.

[0085] In this embodiment, each inner liquid channel section 25 is formed by a flat surface before joining, but liquid channel grooves may be formed in the same way as in the first sheet. In that case, the liquid channel grooves may be in the same position in a plan view, or they may be offset from each other.

[0086] Next, the steam channel groove 26 will be described. The steam channel groove 26 is the part through which the vaporized steam from the evaporation of the working fluid passes, and it constitutes a part of the first channel, the steam channel 4. Figure 16 shows the shape of the steam channel groove 26 in plan view, and Figure 17 shows the cross-sectional shape of the steam channel groove 26.

[0087] As can be seen from these figures, the steam flow channel groove 26 is composed of grooves formed on the inner surface 20a of the main body 21, inside the ring of the outer peripheral liquid flow channel 24. More specifically, the steam flow channel groove 26 in this embodiment is formed between adjacent inner liquid flow channel sections 25, and between the outer peripheral liquid flow channel section 24 and the inner liquid flow channel section 25, and extends in the direction parallel to the long side (x direction) of the rectangle in plan view of the main body 21. Multiple (four in this embodiment) steam flow channel grooves 26 are arranged in the direction parallel to the short side (y direction). Therefore, as can be seen from Figure 17, the second sheet 20 has a shape in the y direction in which convexity is created by the walls of the outer peripheral liquid flow channel section 24 and the inner liquid flow channel section 25, and concaveness is created by the grooves of the steam flow channel groove 26. Since the steam flow channel groove 26 is a groove, its cross-sectional shape includes a bottom portion on the outer surface 20b side and an opening on the opposite side, facing the bottom, which is on the inner surface 20a side. Furthermore, this steam flow channel groove 26 is a groove formed in the outer layer 20e, and the inner layer 20d is laminated inside this groove.

[0088] It is preferable that the steam channel groove 26 is positioned so as to overlap in the thickness direction with the steam channel groove 16 of the first sheet 10 when combined with the first sheet 10. This allows the steam channel groove 16 and the steam channel groove 26 to form the first channel, which is the steam channel 4.

[0089] Figures 16 and 17 show W 11 The width of the steam flow channel groove 26 shown (the width at the opening surface of the groove, in the direction in which the inner liquid flow channel section 25 and the steam flow channel groove 26 are arranged) may be the same as the width W6 of the steam flow channel groove 16 of the first sheet 10, or it may be larger or smaller. Furthermore, the depth of the steam flow channel groove 26, indicated by D5 in Figure 17, is preferably 300 μm or less, but may be 225 μm or less, or 150 μm or less. On the other hand, this depth D5 is preferably 10 μm or more, but may be 25 μm or more, or 50 μm or more. The range of this depth D5 may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Alternatively, the range of depth D5 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. Furthermore, the depths of the steam channel grooves 16 of the first sheet 10 and the steam channel grooves 26 of the second sheet 20 may be the same, or they may be larger or smaller.

[0090] In this embodiment, the cross-sectional shape of the steam channel groove 26 is semi-elliptical, but it may also be rectangular, square, trapezoidal, triangular, semicircular, with a semicircular bottom, with a semi-elliptical bottom, or a combination of several of these shapes. Since the steam channel can smoothly recirculate the working fluid by reducing the steam flow resistance, the shape of the channel cross-section can also be determined from this viewpoint.

[0091] In this embodiment, an example has been described in which one steam channel groove 26 is formed between adjacent inner liquid channel sections 25. However, the embodiment is not limited to this, and two or more steam channel grooves may be arranged side by side between adjacent inner liquid channel sections. Furthermore, if steam channel grooves are formed in the first sheet 10, the second sheet 20 may be configured in such a way that steam channel grooves are not formed in part or all of it.

[0092] The steam channel connecting groove 27 is a groove that connects multiple steam channel grooves 26. This allows for the equalization of steam within the multiple steam channel grooves 4, and enables the steam to be carried over a wider area, allowing for the efficient use of many condensate channel grooves 3, thereby making the recirculation of the working fluid smoother.

[0093] As can be seen in Figures 15, 16, and 18, the steam flow channel connecting groove 27 in this embodiment is formed between the inner liquid flow channel section 25 and the end of the steam flow channel groove 26 in the direction in which it extends, and the outer liquid flow channel section 24. Figure 18 also shows a cross-section of the steam flow channel connecting groove 27 perpendicular to the communication direction.

[0094] Figures 16 and 18 show W 12 The width of the steam flow channel connecting groove 27 shown (size in the direction perpendicular to the communication direction, width at the opening surface of the groove) may be the same as the width W7 of the steam flow channel connecting groove 17 of the first sheet 10, or it may be larger or smaller. Also, the depth of the steam flow channel connecting groove 27 shown as D6 in Figure 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 above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Also, the range of depth D6 may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values. Furthermore, the depth of the steam channel connecting groove 17 of the first sheet 10 and the steam channel connecting groove 27 of the second sheet 20 may be the same, or they may be larger or smaller.

[0095] In this embodiment, the cross-sectional shape of the steam flow channel connecting groove 27 is semi-elliptical, but it is not limited to this and may be rectangular, square, trapezoidal or other quadrilateral, triangular, semicircular, with a semicircular base, with a semi-elliptical base, or a combination of several of these shapes. Since a steam flow channel can enable smooth recirculation by reducing the flow resistance of the steam, the shape of the flow channel cross-section can also be determined from this viewpoint. Furthermore, the steam flow channel connecting groove 27 is also a groove consisting of a groove provided in the outer layer 20e and an inner layer 20d laminated inside this groove.

[0096] In this embodiment, the outer surface 20b of the main body 21 is configured to be a flat surface. This improves adhesion to members that should be in close contact with the outer surface 20b (for example, electronic components to be cooled, or the housing of electronic equipment to which heat should be transferred). 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 rather a shape that allows the outer surface 20b to contribute to the intended heat transfer, etc. Furthermore, as described above, this outer surface 20b is formed by the outer layer 20e. Consequently, the thickness of the outer layer 20e differs depending on the x-direction position and the y-direction position. With such an inner surface 20a, an outer surface 20b, and the inner layer 20d and outer layer 20e constituting them, even when the vapor chamber is made thinner while forming the desired flow path, deformation and damage to the vapor chamber can be suppressed against forces such as external impacts, expansion due to solidification of the working fluid due to low-temperature freezing, and vapor pressure during operation.

[0097] Next, the structure of the vapor chamber 1 when the first sheet 10 and the second sheet 20 are combined will be described. This description will further explain the arrangement, size, shape, etc., of each component of the first sheet 10 and the second sheet 20. Figure 19 shows a cross-section of the vapor chamber 1 cut in the thickness direction along the y-direction indicated by I8-I8 in Figure 1. This figure combines the diagram shown in Figure 5 on the first sheet 10 and the diagram shown in Figure 17 on the second sheet 20 to represent the cross-section of the vapor chamber 1 in this area. Figure 20 shows a magnified view of the area indicated by I9 in Figure 19, and Figure 21 shows the area indicated by I in Figure 1. 10 -I 10 This figure shows a cross-section of the vapor chamber 1 cut along the thickness direction, in the x-direction indicated by the arrow. This figure combines the figure shown in Figure 7 on the first sheet 10 and the figure shown in Figure 18 on the second sheet 20 to represent the cross-section of the vapor chamber 1 in this area.

[0098] As can be seen from Figures 1, 2, and 19-21, the first sheet 10 and the second sheet 20 are arranged to overlap and joined together 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 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 part 12 of the first sheet 10 and the injection part 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 hole 13a of the first sheet 10 with the hole 23a of the second sheet 20.

[0099] The laminate of the first sheet 10 and the second sheet 20 arranges the components of the main body 11 and the main body 21 as shown in Figures 19 to 21. Specifically, it is as follows.

[0100] The outer periphery joint portion 13 of the first sheet 10 and the outer periphery joint portion 23 of the second sheet 20 are arranged to overlap, and the two are joined by 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 this space to form a sealed space 2.

[0101] The outer peripheral liquid flow channel portion 14 of the first sheet 10 and the outer peripheral liquid flow channel portion 24 of the second sheet 20 are arranged to overlap. As a result, the liquid flow channel groove 14a of the outer peripheral liquid flow channel portion 14 and the outer peripheral liquid flow channel portion 24 form a second flow channel, the condensed liquid flow channel 3, through which the condensed liquid, which is the working fluid in a condensed and liquefied state, flows within the hollow portion. Similarly, the inner liquid channel portion 15 of the first sheet 10 and the inner liquid channel portion 25 of the second sheet 20 are arranged to overlap. As a result, the liquid channel groove 15a of the inner liquid channel portion 15 and the inner liquid channel portion 25 form a condensate channel 3, which is a second channel through which the condensate flows within the hollow portion. By forming a narrow channel enclosed on all four sides by walls in this cross-section, the condensate is moved by strong capillary force, enabling smooth circulation. In other words, when considering a channel designed for the flow of condensate, the condensate channel 3 described above can obtain a higher capillary force compared to a channel with a groove where one side of the channel is continuously open. Furthermore, since the condensate flow path 3 is formed separately from the first flow path, the vapor flow path 4, the circulation of the working fluid can be made smoother. Furthermore, adjacent condensate flow paths 3 are connected to each other by communication openings 14c and 15c, thus ensuring the homogenization of the condensate and facilitating smooth circulation of the working fluid.

[0102] For the condensate flow path 3, from the viewpoint of exerting stronger capillary action in the flow path, the aspect ratio (length-to-width ratio) of the flow path cross-section, which is expressed as the flow path width divided by the flow path height, is preferably greater than 1.0. This ratio may be 1.5 or greater, or 2.0 or greater. Alternatively, the aspect ratio may be less than 1.0. This ratio may be 0.75 or less, or 0.5 or less. From a manufacturing standpoint, it is preferable that the channel width is greater than the channel height, and from this standpoint, it is preferable that the aspect ratio is greater than 1.3.

[0103] On the other hand, as can be seen from Figures 19 and 20, the opening of the steam channel groove 16 of the first sheet 10 and the opening of the steam channel groove 26 of the second sheet 20 overlap to face each other and form a channel, which becomes the steam channel 4, the first channel through which steam flows. The cross-sectional area of ​​the condensate flow path 3, which is the second flow path described above, is made smaller than the cross-sectional area of ​​the steam flow path 4, which is the first flow path. More specifically, the average cross-sectional area of ​​two adjacent steam flow paths 4 (flow paths formed by one steam flow path groove 16 and one steam flow path groove 26 in this embodiment) is set to A g The average cross-sectional area of ​​the multiple condensate flow channels 3 (in this embodiment, multiple condensate flow channels 3 formed by one inner liquid flow channel section 15 and one inner liquid flow channel groove 25) located between these two adjacent steam flow channels 4 is Al When this is the case, the condensate flow path 3 and the vapor flow path 4 are such that A l is A g is in a relationship of 0.5 times or less of A, preferably 0.25 times or less. Thereby, the working fluid can be selectively made to easily pass through the first flow path and the second flow path depending on its phase state (gas phase, liquid phase). This relationship may be satisfied in at least a part of the entire vapor chamber, and it is more preferable to satisfy this in the entire vapor chamber.

[0104] As can be seen from FIG. 21, an overlapping flow path is formed such that the opening of the vapor flow path communication groove 17 of the first sheet 10 and the opening of the vapor flow path communication groove 27 of the second sheet 20 face each other.

[0105] On the other hand, also as shown in FIGS. 1 and 2 for the injection parts 12 and 22, their inner surfaces 10a and 20a overlap so as to face each other, and the opening on the opposite side to 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, and an injection flow path 5 that communicates the outside with the hollow part (condensate flow path 3 and vapor flow path 4) between the main bodies 11 and 21 is formed. However, after injecting the working fluid from the injection flow path 5 into the hollow part, since the injection flow path 5 is closed and becomes a sealed space 2, in the vapor chamber 1 in the final form, the outside and the hollow part do not communicate with each other. In this embodiment, an example is shown in which the injection parts 12 and 22 are provided at one end of a pair of ends in the longitudinal direction of the vapor chamber 1, but it is not limited to this, and they may be arranged at any other end, or a plurality of them may be arranged. When a plurality are arranged, for example, they may be arranged at each of a pair of ends in the longitudinal direction of the vapor chamber 1, or may be arranged at one end of the other pair of ends.

[0106] The working fluid is enclosed in the sealed space 2 of the vapor chamber 1. The type of the working fluid is not particularly limited, and working fluids used in ordinary vapor chambers such as pure water, ethanol, methanol, acetone, and mixtures thereof can be used.

[0107] As described above, in the vapor chamber 1, the condensate flow path 3 and the vapor flow path 4 are composed of an outer layer 10e, an outer layer 20e, an inner layer 10d, and an inner layer 20d, and the inner surfaces of the condensate flow path 3 and the vapor flow path 4 are made of the inner layer 10d and the inner layer 20d.

[0108] On the other hand, in this embodiment, the outside of the vapor chamber 1 is formed by outer layers 10e and 20e, and its shape is independent of the inner condensate flow path 3 and vapor flow path 4 (it is flat in this embodiment).

[0109] In this embodiment, the outer layers 10e and 20e have higher strength than the inner layers 10d and 20d, and even if the vapor chamber is made thinner while still having the condensate flow path 3 and the vapor flow path 4, deformation and damage to the vapor chamber can be suppressed. In other words, deformation and damage to the vapor chamber can be suppressed even when subjected to external impacts, expansion due to solidification of the working fluid due to low-temperature freezing, and forces such as vapor pressure during operation.

[0110] On the other hand, the inner layers 10d and 20d can be constructed from materials that have chemical stability with respect to the working fluid and high thermal conductivity, thus keeping thermal resistance low. At the same time, the outer layers 10e and 20e can improve the strength of the vapor chamber, so the pattern formed in the inner layers 10d and 20d where the working fluid moves can be designed with a focus on thermal performance rather than strength improvement, which is advantageous from the standpoint of thermal performance.

[0111] 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 it 0.4 mm or less, the vapor chamber 1 can often be installed inside the electronic device without processing (e.g., forming grooves) to create space for the vapor chamber in the electronic device. Furthermore, according to this embodiment, even such a thin vapor chamber can maintain thermal performance while having high strength and resistance to deformation.

[0112] A vapor chamber like the one described above can be manufactured by, for example, the following process. Figures 22A to 22D illustrate this process. First, prepare sheet 10e' which will become the outer layer 10e of the first sheet 10, as shown in Figure 22A. Next, grooves that will become liquid channel grooves 14a and 15a, steam channel grooves 16 and 17, and steam channel connecting grooves 17 are formed in this sheet 10e' by half-etching, as shown in Figure 22B. Half-etching is the process of etching only partway through the thickness direction without penetrating all the way through.

[0113] Next, as shown in Figure 22C, the inner layer 10d is formed on the half-etched side of the sheet 10e' by sputtering or plating with the material that will become the inner layer 10d. At this time, before sputtering or plating with the material for the inner layer 10d, an intermediate layer may be formed by sputtering or plating to improve adhesion. Examples of intermediate layer formation by sputtering include titanium, nickel, and nickel-chromium intermediate layers, while intermediate layer formation by plating is a so-called strike plating process.

[0114] By including the above steps, the first sheet 10 can be manufactured. This allows for minimizing material removal during processing, even with laminated materials, thereby reducing material loss. Furthermore, since there is no need to etch materials made of layered different metals, corrosion due to the battery effect during processing and a decrease in processing accuracy due to differences in etching rates can be suppressed. Furthermore, while materials formed by rolling and laminating multiple types of metals tend to warp significantly when thinned, this warping can be minimized by manufacturing them as described above, thus improving yield during joining and transportation.

[0115] The second sheet 20 is also manufactured using the above process. After obtaining the first sheet 10 and the second sheet 20, the inner surfaces 10a (inner layer 10d) of the first sheet 10 and the inner surface 20a (inner layer 20d) of the second sheet 20 are placed facing each other, as shown in Figure 22D. The sheets are then positioned using holes 13a and 23a as positioning means, and temporarily fixed in place. The method of temporary fixing is not particularly limited, but examples include resistance welding, ultrasonic welding, and adhesive bonding. Then, after temporary fixing, diffusion bonding is performed to permanently join the first sheet 10 and the second sheet 20. Here, "permanently joined" is not bound by 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 is maintained to the extent that the airtightness of the sealed space 2 can be maintained when the vapor chamber 1 is in operation.

[0116] In the above embodiment, the inner layers 10d and 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 invention is not limited to this, and for example, assuming that the first sheet 10 and the second sheet 20 are joined by brazing, the inner layers 10d and 20d may be made of brazing material. This makes it possible to form and join the inner layers 10d and 20d simultaneously.

[0117] After joining the first sheet 10 and the second sheet 20 as described above, a vacuum is drawn from the formed injection channel 5 to reduce the pressure in the hollow section. Then, working fluid is injected into the reduced-pressure hollow section from the injection channel 5 (see Figure 1) to fill the hollow section with working fluid. The injection channel 5 is then closed by using laser melting or crimping on the injection sections 12 and 22 to create a sealed space. This ensures that the working fluid is stably held inside the sealed space 2.

[0118] In this embodiment of the vapor chamber, the overlap between the internal liquid flow channel 15 and the inner liquid flow channel 25 functions as a support, thereby suppressing the collapse of the sealed space during joining and depressurization. Furthermore, the strength is increased by the outer layers 10e and 20e, which also suppresses the occurrence of such collapse.

[0119] The above describes the manufacturing of vapor chambers by etching, but the manufacturing method is not limited to this. Vapor chambers can also be manufactured by press working, cutting, laser processing, and 3D printing. For example, when manufacturing a vapor chamber using a 3D printer, it is not necessary to join multiple sheets together to create the vapor chamber, making it possible to create a vapor chamber without any joints.

[0120] Next, the operation of the vapor chamber 1 will be explained. Figure 23 schematically shows a portable terminal 40, which is a form of electronic device, with the vapor chamber 1 positioned inside. Here, the vapor chamber 1 is positioned inside the housing 41 of the portable terminal 40 and is therefore represented by a dotted line. Such a portable terminal 40 is composed of a housing 41 that encloses various electronic components and a display unit 42 that is exposed to the outside so that the image can be seen through an opening in the housing 41. Among these electronic components, an electronic component 30 that should be cooled by the vapor chamber 1 is positioned inside the housing 41.

[0121] The vapor chamber 1 is installed inside the casing of a portable terminal or the like, and is attached to an electronic component 30, such as a CPU, that needs to be cooled. 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, etc. The position on the outer surface 10b or outer surface 20b where the electronic component is attached is not particularly limited and is set appropriately in relation to the arrangement of other components in the portable terminal or the like. In this embodiment, as shown by the dotted line in Figure 1, the electronic component 30, which is the heat source to be cooled, is placed in the center of the x and y directions of the main body 11 on the outer surface 10b of the first sheet 10. Therefore, in Figure 1, the electronic component 30 is in a blind spot and is not visible, so it is represented by a dotted line. In this embodiment of the vapor chamber 1, the outer surfaces 10b and 20b are formed from outer layers 10e and 20e, and their shapes are not aligned with the shape of the flow path on the inner side. Therefore, the shapes of the outer surfaces 10b and 20b can be formed from the viewpoint of improving adhesion to the electronic components and housings that they should come into contact with, and in this respect, thermal performance can be improved.

[0122] Figure 24 shows a diagram illustrating the flow of the working fluid. For ease of explanation, the second sheet 20 is omitted in this diagram, and the inner surface 10a of the first sheet 10 is shown.

[0123] When the electronic component 30 generates heat, that heat is transferred through the first sheet 10 by thermal conduction, and the condensate located near the electronic component 30 in the sealed space 2 receives the heat. The condensate that receives this heat absorbs the heat, evaporates, and vaporizes. This cools the electronic component 30.

[0124] The vaporized working fluid becomes steam and moves through the steam channel 4 as shown by the solid straight arrow in Figure 24. Since this flow occurs in a direction away from the electronic component 30, the steam moves away from the electronic component 30. The steam in the steam channel 4 moves away from the heat source, the electronic component 30, and to the outer periphery of the vapor chamber 1, where the temperature is relatively lower. During this movement, the steam is cooled as heat is sequentially absorbed by the first sheet 10 and the second sheet 20. The first sheet 10 and the second sheet 20, having absorbed heat from the steam, transfer that heat to the housing 41 of the electronic device 40, etc., which are in contact with their outer surfaces 10b and 20b, and finally the heat is released into the outside air.

[0125] As the working fluid moves through the steam channel 4, it loses heat and condenses into a liquid. This condensate adheres to the wall surface of the steam channel 4. Meanwhile, since steam is continuously flowing through the steam channel 4, the condensate is directed towards the wall surface indicated by arrow I in Figures 20 and 21. 11 As shown, the condensate moves into the condensate channel 3 as if being pushed in by the steam. In this embodiment, the condensate channel 3 is equipped with communication openings 14c and 15c, as shown in Figures 8 and 14, so the condensate is distributed to multiple condensate channels 3 through these communication openings 14c and 15c.

[0126] The condensate that enters the condensate channel 3 moves towards the heat source, the electronic component 30, due to the capillary force in the condensate channel and the pressure from the vapor, as shown by the dotted straight arrow in Figure 24. In this case, the condensate channel 3 has its openings in the liquid channel grooves 14a and 15a blocked by the second sheet 20, so in cross-section, it has walls on all four sides, which increases the capillary force. This allows for smooth movement of the condensate. Then, the heat from the electronic component 30, which is the heat source, causes it to vaporize again, and the above process is repeated.

[0127] The vapor chamber 1 described so far is an example consisting of two sheets, a first sheet 10 and a second sheet 20. However, it is not limited to this, and a vapor chamber consisting of three sheets, as shown in Figure 25, or four sheets, as shown in Figure 26, is also possible.

[0128] The vapor chamber shown in Figure 25 is a laminate of a first sheet 10, a second sheet 20, and an intermediate sheet, a third sheet 50. The third sheet 50 is positioned between the first sheet 10 and the second sheet 20, and they are joined together.

[0129] 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 composed of inner layers 10d and 20d, respectively, and the outer surfaces 10b and 20b are composed of outer layers 10e and 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 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 0.030 mm or more. This thickness range may be determined by any one of the above-mentioned candidate upper limit values ​​and one of the multiple candidate lower limit values. Alternatively, this thickness range may be determined by any two combinations of the multiple candidate upper limit values, or any two combinations of the multiple candidate lower limit values.

[0130] On the other hand, the third sheet 50 is provided with a steam channel groove 51, a wall 52, a liquid channel groove 53, and a protrusion 54. The steam channel groove 51 is a groove that penetrates the third sheet 50 in the thickness direction, and is a groove similar to the one that forms the first channel, the steam channel 4, by overlapping the steam channel groove 16 and the steam channel groove 26 described above, and has a corresponding shape. The wall 52 is a wall provided between adjacent steam flow channel grooves 51, and has a form corresponding to a wall formed by overlapping the outer peripheral liquid flow channel section 14 and outer peripheral liquid flow channel section 24, and the inner liquid flow channel section 15 and inner liquid flow channel section 25 described above. The liquid flow channel groove 53 is a groove located on the wall 52 facing the first sheet 10, and has a shape corresponding to the liquid flow channel grooves 14a and 15a described above. The liquid flow channel groove 53 forms the condensed liquid flow channel 3, which is the second flow channel. The protrusion 54 is a protrusion positioned between adjacent liquid flow channel grooves 53, and is positioned in a form corresponding to the protrusions 14b and 15b described above.

[0131] Furthermore, grooves are formed in the third sheet 50 to serve as condensate flow channels 3 and vapor flow channels 4, and the inner layer 50d is laminated inside these grooves. Also, since the third sheet 50 does not form an outer surface, the area where the inner layer 50d is laminated is the base layer 50f, which is the foundation layer for laminating the inner layer 50d. Therefore, the wall 52 is configured such that the inner layer 50d is laminated around the outer periphery of the base layer 50f. The material constituting the base layer 50f can be considered in the same way as the outer layer 10e described above.

[0132] A vapor chamber with the above configuration will have the same effect as described above.

[0133] The vapor chamber shown in Figure 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 together in the order of first sheet 10, third sheet 60, fourth sheet 70, and second sheet 20, starting from the first sheet 10 side.

[0134] In this embodiment, the inner surfaces 10a and 20a and outer surfaces 10b and 20b of the first sheet 10 and the second sheet 20 are all flat. The inner surfaces 10a and 20a are composed of inner layers 10d and 20d, respectively, and the outer surfaces 10b and 20b are composed of outer layers 10e and 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 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 0.030 mm or more. This range of thickness may be determined by any one of the above-mentioned candidate upper limit values ​​and one of the above-mentioned candidate lower limit values. Alternatively, this range of thickness may be determined by any two combinations of the above-mentioned candidate upper limit values, or any two combinations of the above-mentioned candidate lower limit values. For clarity, the hatching of the inner layers is omitted in this representation.

[0135] The third sheet 60 is provided with a liquid flow channel groove 14a, a liquid flow channel groove 15a, and a steam flow channel groove 16. In this embodiment, the liquid flow channel groove 14a, liquid flow channel groove 15a, and steam flow channel groove 16 are grooves that penetrate the third sheet 60 in the thickness direction, but otherwise they can be in the same form as the liquid flow channel groove 14a, liquid flow channel groove 15a, and steam flow channel groove 16 described above. The third sheet 60 has grooves formed therein that serve as condensate flow channels 3 and vapor flow channels 4, and the inner layer 60d is laminated inside these grooves. Furthermore, since the third sheet 60 does not form an outer surface, the area where the inner layer 60d is laminated is considered to be the base layer 60f, which serves as the foundation for laminating the inner layer 60d. The material constituting the base layer 60f can be considered in the same way as the outer layer 10e described above.

[0136] The fourth sheet 70 is equipped with a steam flow channel groove 26. In this embodiment, the steam flow channel groove 26 is a groove that penetrates the fourth sheet 70 in the thickness direction, but otherwise, it can have the same form as the steam flow channel groove 26 described above. Furthermore, a groove is formed in the fourth sheet 70, which serves as a steam channel 4, and the inner layer 70d is laminated inside this groove. Also, since the fourth sheet 70 does not form an outer surface, the area where the inner layer 70d is laminated is considered to be the base layer 70f, which serves as the foundation for laminating the inner layer 60d. The material constituting the base layer 70f can be considered in the same way as the outer layer 10e described above.

[0137] When these sheets are stacked, a second condensate flow path 3 is formed, surrounded by the first sheet 10, the condensate flow path 14a, and the fourth sheet 70, and another second condensate flow path 3 is formed, surrounded by the first sheet 10, the condensate flow path 15a, and the fourth sheet 70. Similarly, when steam channel groove 16 and steam channel groove 26 overlap and are positioned between the first sheet 10 and the second sheet 20, they form the first channel, which is steam channel 4. A vapor chamber with the above configuration will have the same effect as described above.

[0138] [Second form] Figure 27 shows an external perspective view of the vapor chamber 101 according to the second embodiment, and Figure 28 shows an exploded perspective view of the vapor chamber 101. As can be seen in Figures 27 and 28, the vapor chamber 101 in this embodiment has a first sheet 110 and a second sheet 120. As will be explained later, the first sheet 110 and the second sheet 120 are overlapped and joined (diffusion bonding, brazing, etc.), forming a hollow space between the first sheet 110 and the second sheet 120. The working fluid is sealed in this hollow space to form a sealed space 102 (see, for example, Figure 45).

[0139] In this embodiment, the first sheet 110 is a sheet-like member as a whole, and is L-shaped in plan view. Figure 29 shows a perspective view of the first sheet 110 as seen from the inner surface 110a side, and Figure 30 shows a plan view of the first sheet 110 as seen from the inner surface 110a side. Also, Figure 31 shows the I in Figure 30. 101 -I 101 The cross-section of the first sheet 110 after cutting is shown. 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 for the working fluid is formed on the inner surface 110a side. As will be described later, the inner surface 110a of the first sheet 110 and the inner surface 120a of the second sheet 120 are overlapped so that they face each other, forming a hollow space, into which the working fluid is sealed to form a sealed space 102.

[0140] The thickness of the first sheet 110 is not particularly limited, but can be considered in the same way as the first sheet 10 described above.

[0141] The first sheet 110 comprises a main body 111 and an injection section 112. The main body 111 is sheet-shaped and forms the portion through which the working fluid moves. In this embodiment, it is L-shaped with a curved portion in plan view. The injection section 112 is the part into which the working fluid is injected into the hollow section formed by the first sheet 110 and the second sheet 120, and in this embodiment, it is a rectangular sheet in plan view that protrudes from the L-shape of the main body 111 in plan view. In this embodiment, both the inner surface 110a and the outer surface 110b of the injection section 112 of the first sheet 110 are flat surfaces.

[0142] A structure for the movement of the working fluid is formed on the inner surface 110a side of the main body 111. Specifically, this structure includes an outer peripheral joint 113, an outer peripheral fluid flow channel 114, an inner fluid flow channel 115, a steam flow channel groove 116, and a steam flow channel communication groove 117 on the inner surface 110a side of the main body 111.

[0143] The outer peripheral joint portion 113 is a surface formed on the inner surface 110a side of the main body 111, along the outer circumference of the main body 111. When this outer peripheral joint portion 113 overlaps with the outer peripheral joint portion 123 of the second sheet 120 and is joined (diffusion bonding, brazing, etc.), a hollow portion is formed between the first sheet 110 and the second sheet 120, and the working fluid is sealed in there to form a sealed space 102. The width of the outer peripheral joint portion 113 can be set as appropriate as needed, but at its narrowest point, it can be considered in the same way as the width W1 described for the first sheet 10.

[0144] The outer peripheral fluid channel section 114 functions as a fluid channel section and is part of the condensed fluid channel section 103 (see, for example, Figure 46), which is the channel through which the working fluid passes when it condenses and liquefies. Figure 32 shows arrow I in Figure 31. 102 The part shown in Figure 33 is shown in Figure 30 as I 103 -I 103 The cross-section is shown. The cross-sectional shape of the outer peripheral fluid flow channel 114 is shown in all figures. Also, in Figure 34, arrow I is shown in Figure 32. 105 This shows an enlarged plan view of the outer peripheral fluid flow channel 114 as seen from the direction indicated.

[0145] As can be seen from these figures, the outer peripheral fluid channel section 114 is formed along the inner surface 110a of the main body 111, along the inside of the outer peripheral joint section 113, and is provided in an annular shape along the outer circumference of the sealed space 102. In addition, the outer peripheral fluid channel section 114 has multiple fluid channel grooves 114a that extend parallel to the direction in which the outer peripheral fluid channel section 114 extends, and the multiple fluid channel grooves 114a are spaced apart in a direction different from the direction in which the fluid channel grooves 114a extend. Therefore, as can be seen from Figures 32 and 33, in the cross-section of the outer peripheral fluid channel section 114, the recessed fluid channel grooves 114a and the protruding walls 114b between the fluid channel grooves 114a are formed in an uneven manner. Since the liquid flow channel groove 114a is a groove, its cross-sectional shape includes a bottom and an opening located on the opposite side of the bottom.

[0146] By providing multiple liquid flow channel grooves 114a in this manner, the depth and width of each individual liquid flow channel groove 114a can be reduced, thereby reducing the cross-sectional area of ​​the condensate flow channel 103 (see, for example, Figure 46) and enabling the use of large capillary forces. On the other hand, by having multiple liquid flow channel grooves 114a, the total internal volume of the condensate flow channel 103 can be ensured to be of an appropriate size, allowing the required flow rate of condensate to be transmitted.

[0147] Furthermore, in the outer peripheral liquid flow channel section 114, as can be seen in Figure 23, adjacent liquid flow channel grooves 114a are connected by communication openings 114c provided at intervals in the wall 114b. This promotes the equalization of the amount of condensate among multiple liquid flow channel grooves 114a, allowing the condensate to flow efficiently. In addition, the communication openings 114c provided in the wall 114b adjacent to the steam flow channel groove 116 that forms the steam flow channel 104 connect the steam flow channel 104 and the condensate flow channel 103. Therefore, by providing the communication openings 114c, the condensate generated in the steam flow channel 104 can be smoothly moved to the condensate flow channel 103, and the steam generated in the condensate flow channel 103 can be smoothly moved to the steam flow channel 104, thereby promoting the smooth movement of the working fluid.

[0148] In this embodiment, as shown in Figure 34, a communication opening 114c is positioned opposite to a single liquid flow channel groove 114a at the same position in the direction in which the liquid flow channel groove 114a extends, with the groove in between. However, the embodiment is not limited to this, and the communication opening 114c may be positioned following the example described using Figure 9.

[0149] Furthermore, the width of the outer peripheral fluid flow channel 114 can be considered in the same way as the width W2 described in the first sheet 10. Regarding the liquid flow channel groove 114a, its width can be considered the same as the width W3 described for the first sheet 10, and its depth the same as the depth D1 described for the first sheet 10. However, it is preferable that the depth of the liquid flow channel 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 tearing when the working fluid freezes. Furthermore, regarding wall 114b, Figures 32 and 34 show W 101 The width indicated is preferably between 20 μm and 300 μm. If this width is less than 20 μm, it becomes prone to rupture due to repeated freezing and thawing of the working fluid, and if this width is greater than 300 μm, the width of the communication opening 114c becomes too large, which may hinder the smooth communication of the working fluid with the adjacent condensate flow path 103.

[0150] Regarding the communication opening 114c, the size of the communication opening 114c along the direction in which the liquid flow channel groove 114a extends can be considered in the same way as the size L1 described in the first sheet 10, and the pitch of adjacent communication openings 114c in the direction in which the liquid flow channel groove 114a extends can be considered in the same way as the pitch L2 described in the first sheet 10.

[0151] In this embodiment, the cross-sectional shape of the liquid flow channel groove 114a is semi-elliptical, but it is not limited to this, and may be square, rectangular, trapezoidal, triangular, semicircular, with a semicircular base, with a semi-elliptical base, etc.

[0152] Furthermore, it is preferable that the liquid flow channel groove 114a is formed continuously along the edge of the sealed space. That is, it is preferable that the liquid flow channel groove 114a extends in an annular shape around the entire circumference without being interrupted by other components. This reduces factors that hinder the movement of the condensate, allowing the condensate to move smoothly.

[0153] In this embodiment, an outer peripheral liquid flow channel 114 is provided, but the outer peripheral liquid flow channel 114 is not necessarily required. Depending on the shape of the vapor chamber, its relationship to the equipment to which it is applied, and the operating environment, an embodiment without the outer peripheral liquid flow channel 114 may be provided. In this embodiment, the outer periphery of the sealed space can be used as a vapor flow channel, and heat can be transported to the outer periphery of the vapor chamber by vapor, which may allow for greater heat uniformity.

[0154] Returning to Figures 29 to 31, the inner liquid flow channel section 115 will be explained. The inner liquid flow channel section 115 also functions as a liquid flow channel section and is a part of the condensed liquid flow channel 103 through which the working fluid passes when it condenses and liquefies. Figure 35 shows part of Figure 31 I 105 The part indicated by is shown. This figure also shows the cross-sectional shape of the inner liquid flow channel 115. Also, Figure 36 shows the part indicated by arrow I in Figure 35. 106 An enlarged plan view of the inner liquid flow channel section 115, as seen from the direction indicated, is shown.

[0155] As can be seen from these figures, the inner liquid flow channel section 115 is formed on the inner surface 110a of the main body 111, inside the ring of the annular outer liquid flow channel section 114 (or outer joint section 113). As can be seen from Figures 29 and 30, the inner liquid flow channel section 115 in this embodiment is a convex ridge that extends with a curved portion, and multiple (five in this embodiment) inner liquid flow channel sections 115 are arranged with intervals in a direction different from the direction in which they extend, and are positioned between the steam flow channel grooves 116. Each inner liquid flow channel section 115 has a liquid flow channel groove 115a formed in it, which is a groove parallel to the direction in which the inner liquid flow channel section 115 extends. Multiple liquid flow channel grooves 115a are arranged at predetermined intervals in a direction different from the direction in which the liquid flow channel grooves 115a extend. Therefore, as can be seen from Figures 31 and 36, in the cross-section of the inner liquid flow channel section 115, the recessed liquid flow channel grooves 115a and the convex parts between the liquid flow channel grooves 115a, which are walls 115b, are formed in an uneven manner. Since the liquid flow channel groove 115a is a groove, its cross-sectional shape includes a bottom and an opening located on the opposite side of the bottom.

[0156] By providing multiple liquid flow channel grooves 115a in this manner, the depth and width of each individual liquid flow channel groove 115a can be reduced, thereby reducing the cross-sectional area of ​​the condensate flow channel 103 (see, for example, Figure 46) and enabling the use of large capillary forces. On the other hand, by having multiple liquid flow channel grooves 115a, the total internal volume of the condensate flow channel 103 can be ensured to be of an appropriate size, allowing the required flow rate of condensate to be transmitted.

[0157] Furthermore, in the inner liquid flow channel section 115, as can be seen in Figure 36, following the example of the outer liquid flow channel section 114, adjacent liquid flow channel grooves 115a are connected by communication openings 115c provided at intervals in the wall 115b, similar to Figure 34. This promotes the equalization of the amount of condensate among multiple liquid flow channel grooves 115a, allowing the condensate to flow efficiently. In addition, the communication opening 115c provided in the wall 115b adjacent to the steam flow channel groove 116 that forms the steam flow channel 104 connects the steam flow channel 104 and the condensate flow channel 103. Therefore, as will be explained later, by configuring the communication opening 115c, the condensate generated in the steam flow channel 104 can be smoothly moved to the condensate flow channel 103, and the steam generated in the condensate flow channel can be smoothly moved to the steam flow channel 104, thereby promoting the smooth movement of the working fluid.

[0158] In the inner liquid flow channel section 115, following the example in Figure 9, communication openings 115c may be arranged at different positions in the direction in which the liquid flow channel groove 115a extends, flanking the groove.

[0159] The width of the inner liquid flow channel section 115, which has the above configuration, can be considered in the same way as the width W4 described in the first sheet 10.

[0160] Regarding the fluid flow channel groove 115a, its groove width can be considered in the same way as W5 and groove depth as D2 described for the first sheet 10. It is preferable that the groove depth be smaller than the remaining sheet thickness obtained by subtracting the groove depth from the thickness of the first sheet 110. This more reliably prevents the sheet from tearing when the working fluid freezes.

[0161] Also, regarding wall 115b, Figures 35 and 36 show W 102 The width indicated is preferably between 20 μm and 300 μm. If this width is less than 20 μm, it becomes prone to rupture due to repeated freezing and thawing of the working fluid, and if this width is greater than 300 μm, the width of the communication opening 115c becomes too large, which may hinder smooth communication between the condensate flow paths 103.

[0162] Regarding the communication opening 115c, the size of the communication opening 115c along the direction in which the liquid flow path groove 115a extends can be considered in the same way as L3 described for the first sheet 10, and the pitch of adjacent communication openings 115c in the direction in which the liquid flow path groove 115a extends can be considered in the same way as L4 described for the first sheet 10.

[0163] Also, in this embodiment, the cross-sectional shape of the liquid flow path groove 115a is semi-elliptical, but it is not limited to this, and it may be a quadrilateral such as a square, rectangle, trapezoid, a triangle, a semi-circle, a semi-elliptical bottom, or a semi-elliptical bottom.

[0164] Next, the vapor flow path groove 116 will be described. The vapor flow path groove 116 is a part of the vapor flow path 104 where the working fluid in vapor and condensate states moves. FIGS. 30 show the shape of the vapor flow path groove 116 in plan view, and FIGS. 31 show the cross-sectional shape of the vapor flow path groove 116.

[0165] As can be seen from these figures, the vapor flow path groove 116 is constituted by a groove formed inside the ring of the outer peripheral liquid flow path portion 114 which is annular on the inner surface 110a of the main body 111. Specifically, the vapor flow path groove 116 of this embodiment is a groove formed between adjacent inner liquid flow path portions 115 and between the outer peripheral liquid flow path portion 114 and the inner liquid flow path portion 115, and extends with a curved portion. And a plurality (six in this embodiment) of vapor flow path grooves 116 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 the inner liquid flow path portion 115 is a convex strip and the vapor flow path groove 116 is a concave strip, with the concavities and convexities repeated. Here, since the vapor flow path groove 116 is a groove, in its cross-sectional shape, it has a bottom and an opening existing at a portion on the opposite side facing the bottom.

[0166] The vapor flow path groove 116 may be configured such that when the vapor flow path 104 is formed in combination with the vapor flow path groove 126 of the second sheet 120, the working fluid moves in the vapor flow path 104. The width of the steam channel groove 116 is formed to be at least larger than the widths of the liquid channel grooves 114a and 115a described above, and can be considered in the same way as the width W6 described in the first sheet 10. On the other hand, the depth of the steam channel groove 116 is formed to be at least greater than the depths of the liquid channel grooves 114a and 115a described above, and can be considered in the same way as the depth D3 explained in the first sheet 10. These features ensure stable movement of the working fluid when the steam channel is formed, and by making the cross-sectional area of ​​the steam channel groove larger than that of the liquid channel groove, the steam, which has a larger volume than the condensate due to the properties of the working fluid, can be moved smoothly.

[0167] Here, it is preferable that the steam channel groove 116 is configured such that, when combined with the second sheet 120 to form the steam channel 104, as will be explained later, the width of the steam channel 104 is greater than its height (size in the thickness direction). Therefore, the aspect ratio, which is expressed as the height divided by the width, is preferably 4.0 or more, and more preferably 8.0 or more.

[0168] In this embodiment, the cross-sectional shape of the steam channel groove 116 is semi-elliptical, but it is not limited to this and may be a square, rectangle, trapezoid, triangle, semicircle, with a circular base, with a semi-elliptical base, etc.

[0169] The steam flow channel connecting groove 117 connects multiple steam flow channel grooves 116 and, in combination with the steam flow channel connecting groove 127 of the second sheet 120, forms a channel that connects multiple steam flow channels 104 formed by the steam flow channel grooves 116 at their ends. This allows for smooth movement of the working fluid generated in the steam flow channels 104 in the direction in which the inner liquid flow channel section 115 extends. The steam channel connecting groove 117 can be considered in the same way as the steam channel connecting groove 17 described on the first sheet 10.

[0170] In this embodiment, the first sheet 110 includes a curved portion 118c in the liquid channel groove 114a (outer liquid channel portion 114), the liquid channel groove 115a (inner liquid channel portion 115), and the steam channel groove 116, where the direction in which these channels extend changes. In other words, the first sheet 110 includes a liquid channel groove 114a (outer liquid channel section 114), a liquid channel groove 115a (inner liquid channel section 115), and a straight section 118a in which the steam channel groove 116 extends linearly in the x direction, a straight section 118b in which the liquid channel groove 114a (outer liquid channel section 114), a liquid channel groove 115a (inner liquid channel section 115), and the steam channel groove 116 extend linearly in the y direction, and a curved section 118c connecting the liquid channel groove 114a (outer liquid channel section 114), a liquid channel groove 115a (inner liquid channel section 115), and the steam channel groove 116 in the straight sections 118a and 118b. Accordingly, the curved section 118c has one end connected to one straight section 118a and the other end connected to the other straight section 118b, and the liquid flow channel groove 114a (outer liquid flow channel section 114), the liquid flow channel groove 115a (inner liquid flow channel section 115), and the steam flow channel 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 section and the curved section can be defined as the point in each groove where the direction of flow begins to change. The same reasoning can be applied to subsequent sections.

[0171] In this embodiment, when considering the width of the multiple steam flow channels 116 in the curved section 118c, the width is 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 section, making the movement of the working fluid smoother and increasing the heat transport capacity. The specific form for this is not particularly limited, but examples include the forms shown in Figures 37, 38, 39, and 40.

[0172] Figures 37 to 40 illustrate the process by focusing on a single steam channel groove 116. The symbols used in these figures have the following meanings: • In the curved section 118c, the steam channel groove 116 has an inner wall w in The radius of curvature is r inIts center is in the shape of an arc of O1. • In the curved section 118c, the steam channel groove 116 has an outer wall w out The radius of curvature is r out As will be explained later, depending on the morphology, its center is an arc shape of O1, O2, O3, or O4. • Of the multiple steam channel grooves 116 belonging to the curved section 118c, the width of the narrowest steam channel groove is α, while the widths of the other steam channel grooves 116 are widened to β (α < β). In other words, in this embodiment, the width of the outermost steam channel groove 116 among the multiple steam channels 116 belonging to the curved section 118c is α. The dotted curve represents a hypothetical line when the width of the steam channel groove 116 is α, and the radius of curvature in this case is r c Its center is in the shape of an arc of O1. The radius of the curve can be defined by considering a circle that passes through three points: two points where the orientation of the walls (inner wall, outer wall) begins to change in the curved section, and one point midway between these two points. The radius of this circle is defined as the radius of the curve. When the curve is considered as part of a circle or ellipse, as shown in Figures 37 to 40, the side of the curve that is closer to the center of the circle or ellipse (i.e., the O1, O2, O3, O4 side) is considered the "inside" of the curve, and the side opposite to the center of the circle or ellipse is considered the "outside" of the curve. Furthermore, the shape of the curve is not limited to a shape like a part of a perfect circle; it may also be a shape like a part of an ellipse, or a shape in which some of the multiple steam flow channels arranged in the curved section are straight. The shape of the curved section can be considered similarly below.

[0173] In the example shown in Figure 37, the outer wall w of the steam flow channel groove 116 in the curved section 118c. out Radius r of curvature out The radius of curvature r c Larger than (r out >r c ) and its center is O1. In this example, in the steam flow channel groove 116 belonging to the curved section 118c, the steam flow channel groove 116 located on the inside is r out The goal is to make it larger. This will also make the groove width β as large as the steam flow channel groove 116 located on the inside.

[0174] In the example shown in Figure 38, the outer wall w of the steam flow channel groove 116 in the curved section 118c. out Radius r of curvature out The radius of curvature r c Same as (r out =r c ) However, its center is located at O2, which is shifted towards the steam channel groove 116 side from O1. In this example, in the steam channel groove 116 belonging to the curved section 118c, the outer wall w of the steam channel groove 116 is located on the inside. out The center (O2) should be positioned closer to the steam flow channel groove 116. This will cause the groove width β to become larger as the steam flow channel groove 116 is positioned further inward.

[0175] In the example shown in Figure 39, the outer wall w of the steam flow channel groove 116 in the curved section 118c. out Radius r of curvature out The radius of curvature r in and radius of curvature r c Smaller than (r out <r in <r c ), and its center is located at O3, which is shifted towards the steam channel groove 116 side than O1. In this example, in the steam channel groove 116 belonging to the curved section 118c, r out Depending on both the size and the position of O3, the width β should be made larger for the steam flow channel groove 116 located on the inside.

[0176] In the example shown in Figure 40, the outer wall w of the steam flow channel groove 116 in the curved section 118c. out Radius r of curvature out and the inner wall lol in Radius r of curvature in and are the same, and the r out The center O4 is r in It is located on the side shifted towards the steam channel groove 116 from the center O1. In this example configuration, in the steam channel groove 116 belonging to the curved section 118c, the width β should be made larger for steam channel grooves 116 located further inward, depending on the position of O4.

[0177] Note that in the examples of Figures 37 and 38, the outer wall wout In this configuration, the straight section and the curved section are connected by a single inflection. However, this single inflection may be replaced with a number of small inflections or a curve, creating a connection that allows for a gradual and smooth change in direction.

[0178] While there are no particular limitations on the degree to which the width of the inner steam channel grooves increases, it is preferable that they be about 3% to 20% wider than the adjacent grooves located on the outside. This ratio does not need to be constant or regular across multiple grooves and can be set as appropriate.

[0179] The width of the steam flow channel 116 in the curved section 118c is not particularly limited to the width of the steam flow channel 116 in the straight section 118b, but the width may be increased by 10% to 100% compared to the straight sections 118a and 118b. By setting it within this range, it is possible to balance the flow resistance of the straight section 118b and the flow resistance of the curved section 118c.

[0180] Furthermore, while the above description focused on the width of the steam channel groove, the depth of the steam channel groove 116 in the curved section 118c may be changed instead, or in addition to that. That is, in the multiple steam channel grooves 116 belonging to the curved section 118c, the outermost steam channel groove 116 may be the shallowest, and the innermost steam channel groove 116 may be the deepest. By changing the depth direction (z direction), the expansion in the planar direction (x and y directions) is suppressed, which allows for securing more space for condensate channels and improving heat transport capacity, or allows for a wider outer periphery joint and improves the reliability of pressure resistance.

[0181] That is, by configuring the widths of the vapor flow path grooves 116 in the curved portion 118c to be different for each groove as described above, when the first sheet 110 and the second sheet 120 are combined, the width of the vapor flow path arranged on the inner side in the curved portion can be made larger than the width of the vapor flow path arranged on the outer side. As a result, in the curved portion, the flow path cross-sectional area of the vapor flow path arranged on the inner side can be made larger than the flow path cross-sectional area of the vapor flow path arranged on the outer side. On the other hand, by configuring the depths of the vapor flow path grooves 116 in the curved portion 118c to be different for each groove, when the first sheet 110 and the second sheet 120 are combined, the height of the vapor flow path arranged on the inner side in the curved portion can be made larger than the height of the vapor flow path arranged on the outer side. As a result, in the curved portion, the flow path cross-sectional area of the vapor flow path arranged on the inner side can be made larger than the flow path cross-sectional area of the vapor flow path arranged on the outer side.

[0182] Also, in the curved portion 118c, regarding the communication openings 114c and the communication opening 115c provided in the walls 114b and 115b that partition the liquid flow path grooves 114a and 115a and the vapor flow path groove 116 (see FIGS. 34 and 36), the pitch thereof can be configured to be different from that of other portions (the straight portions 118a, 118b). This may be such that the pitch of the communication openings in the curved portion is larger or smaller than the pitch of the curved portion in the straight portion. Which form to adopt can be comprehensively determined and adopted in consideration of the influence of the overall shape of the vapor chamber, the position of the heat source, etc., so as to reduce the flow resistance. Alternatively, for this curved portion 118c, the communication openings 114c and 115c provided in the walls 114b and 115b that partition the liquid flow path grooves 114a and 115a and the vapor flow path groove 116 may not be provided.

[0183] In a configuration where the pitch of the communication openings in the curved section is larger than the pitch of the communication openings in the straight section, it is possible to suppress the working fluid flowing through the steam channel groove 116 (steam channel 104) from entering the communication openings 114c and 115c in the curved section 118c. In the curved section 118c, the working fluid moving through the steam channel groove 116 (steam channel 104) is subjected to a force that causes it to flow directly into the communication openings 114c and 115c due to its flow direction. As a result, steam tends to enter the condensate channel 103, and the flow resistance tends to increase due to the irregularities of the communication openings 114c and 115c. In contrast, by increasing the pitch of the communication openings 114c and 115c that are in contact with the steam flow channel groove 116 at the curved section 118c, or by eliminating the communication openings 114c and 115c that are in contact with the steam flow channel groove 116, it is possible to suppress such an increase in flow resistance, further reduce the difference in flow resistance between each steam flow channel groove 116 (steam flow channel 104), improve the balance of the movement of the working fluid, and in some cases increase the heat transport capacity.

[0184] On the other hand, in a configuration where the pitch of the communication openings in the curved section is smaller than the pitch of the communication openings in the straight section, the steam flowing through the steam channel groove (steam channel) has more opportunities to hit the wall surface strongly in the curved section, making it more prone to condensation. In this case, by making the pitch of the communication openings in the curved section smaller than the pitch of the communication openings in the straight section, the number of communication openings can be increased, allowing the condensate to be smoothly introduced into the liquid channel groove (condensate channel), and preventing the steam channel from being blocked by the condensate. This can suppress the increase in flow resistance, further reduce the difference in flow resistance between each steam channel groove (steam channel), improve the balance of the movement of the working fluid, and in some cases increase the heat transport capacity.

[0185] Alternatively, instead of the above-mentioned pitch size, the length of the wall between adjacent communication openings in the curved section (the size in the direction along the flow path) may be configured to be larger or smaller than the length of the wall in the straight section. In this case, the length of the wall belonging to the curved section does not need to be constant and may differ from wall to wall. In this case, the relationship between the length of the wall in the curved section and the length of the wall in the straight section shall be determined by the relationship between the average values ​​of the wall lengths belonging to each section.

[0186] Next, the second sheet 120 will be described. In this embodiment, the second sheet 120 is also a sheet-like component as a whole, and is curved in an L-shape when viewed from above. Figure 41 is a perspective view of the second sheet 120 as seen from the inner surface 120a side, and Figure 42 is a plan view of the second sheet 120 as seen from the inner surface 120a side. Also, Figure 43 shows the same as in Figure 42. 107 -I 107 The cross-section of the second sheet 120 when cut is shown. Also, Figure 44 shows the same as in Figure 42. 108 -I 108 The cross-section of the second sheet 120 after cutting is shown. 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 on the inner surface 120a side for the working fluid to move. As will be described later, the inner surface 120a of the second sheet 120 and the inner surface 110a of the first sheet 110 described above are overlapped and joined so that they face each other, creating a hollow space where the working fluid is sealed to form a sealed space 102.

[0187] The thickness of the second sheet 120 is not particularly limited, but it can be considered in the same way as the second sheet 20 mentioned above.

[0188] The second sheet 120 comprises a main body 121 and an injection section 122. The main body 121 is sheet-shaped and forms the portion through which the working fluid moves. In this embodiment, it is L-shaped with a curved portion in plan view. The injection section 122 is the part into which the working fluid is injected into the hollow section formed by the first sheet 110 and the second sheet 120. In this embodiment, it is a rectangular sheet in plan view that protrudes from the L-shape of the main body 121 in plan view. In this embodiment, the injection section 122 of the second sheet 120 has an injection groove 122a formed on the inner surface 120a side, and communicates with the inside of the main body 121 (the hollow section, the part that should become the sealed space 102) from the side surface 120c of the second sheet 120.

[0189] A structure for the movement of 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 peripheral joint 123, an outer peripheral fluid flow channel 124, an inner fluid flow channel 125, a steam flow channel groove 126, and a steam flow channel communication groove 127.

[0190] The outer peripheral joint portion 123 is a surface formed on the inner surface 120a side of the main body 121, along the outer circumference of the main body 121. When this outer peripheral joint portion 123 overlaps with the outer peripheral joint portion 113 of the first sheet 110 and is joined (diffusion bonding, brazing, etc.), a hollow portion is formed between the first sheet 110 and the second sheet 120, and the working fluid is sealed in there to form a sealed space 102. It is preferable that the width of the outer peripheral joint portion 123 is the same as the width of the outer peripheral joint portion 113 of the main body 111 of the first sheet 110 described above.

[0191] The outer peripheral fluid channel section 124 functions as a fluid channel section and is part of the condensed fluid channel section 103 (see, for example, Figure 46), which is the channel through which the working fluid passes when it condenses and liquefies.

[0192] The outer peripheral liquid channel portion 124 is formed along the inner surface 120a of the main body 121, along the inside of the outer peripheral joint portion 123, and is formed to form an annular shape along the outer circumference of the sealed space 102. In this embodiment, as can be seen from Figures 43 and 44, the outer peripheral liquid channel portion 124 of the second sheet 120 is a flat surface and flush with the outer peripheral joint portion 123 before joining with the first sheet 110. This closes the openings of at least some of the liquid channel grooves 114a of the first sheet 110 described above, forming the condensed liquid channel 103. A detailed description of the combination of the first sheet 110 and the second sheet 120 will be explained later. In the second sheet 120, the outer peripheral joint portion 123 and the outer peripheral liquid flow channel portion 124 are flush, so structurally there is no boundary line that distinguishes the two. However, for clarity, the boundary between the two is represented by a dotted line in Figures 41 and 42.

[0193] The width of the outer peripheral liquid flow channel portion 124 is not particularly limited and may be the same as or different from the width of the outer peripheral liquid flow channel portion 114 of the first sheet 110. When the width of the outer peripheral liquid flow channel section 124 is made smaller than the width of the outer peripheral liquid flow channel section 113, at least a portion of the outer peripheral liquid flow channel section 114 will have an opening in the liquid flow channel groove 114a that is not closed by the outer peripheral liquid flow channel section 124. This allows condensed liquid to enter more easily and vapor to escape more easily, thus enabling smoother movement of the working fluid.

[0194] In this embodiment, the outer peripheral liquid flow channel portion 124 of the second sheet 120 is configured to be a flat surface, but it is not limited to this, and liquid flow channel grooves may be provided in the same way as the outer peripheral liquid flow channel portion 114. In this case, the liquid flow channel grooves of the first sheet and the liquid flow channel grooves of the second sheet can be superimposed to form a condensed liquid flow channel 103.

[0195] Furthermore, as explained in the first sheet, the outer peripheral liquid flow channel 124 is not necessarily required in this embodiment, and the embodiment may be configured without the outer peripheral liquid flow channel 124.

[0196] Next, the inner liquid flow channel section 125 will be described. The inner liquid flow channel section 125 is also a liquid flow channel section and is one of the parts that make up the condensed liquid flow channel 103.

[0197] As can be seen in Figures 41 to 44, the inner liquid flow channel section 125 is formed on the inner surface 120a of the main body 121, inside the ring that is annular to the outer liquid flow channel section 124. In this embodiment, the inner liquid flow channel section 125 is a convex ridge that extends with a curved portion, and multiple (five in this embodiment) inner liquid flow channel sections 125 are arranged with spacing in a direction different from the direction in which they extend, and are positioned between the steam flow channel grooves 126. In this embodiment, each inner liquid channel portion 125 is formed such that its inner surface 120a side becomes a flat surface before joining with the first sheet 110. This closes the openings of at least some of the liquid channel grooves 115a of the multiple liquid channel grooves 115a of the first sheet 110, thereby forming a condensed liquid channel 103. In this embodiment, if no groove for forming the condensed liquid channel 103 is formed in the inner liquid channel section 125, it is preferable that the thickness of the second sheet 120 is greater than or equal to the thickness of the first sheet 110 minus the depth of the liquid channel groove 115a. This prevents rupture (breakage) on the second sheet side in the vapor chamber.

[0198] In this embodiment, the inner liquid channel portion 125 of the second sheet 120 is configured to be a flat surface, but it is not limited to this, and liquid channel grooves may be provided in the same way as the inner outer liquid channel portion 115. In this case, the liquid channel grooves of the first sheet and the liquid channel grooves of the second sheet can be superimposed to form a condensed liquid channel 103.

[0199] The width of the inner liquid channel section 125 is not particularly limited and may be the same as or different from the width of the inner liquid channel section 115 of the first sheet 110. In this embodiment, the width of the inner liquid channel section 125 and the width of the inner liquid channel section 115 are the same. If the width of the inner liquid channel section 125 and the width of the inner liquid channel section 115 are different, the effect of misalignment during joining can be reduced. Furthermore, if the width of the inner liquid channel section 125 is made smaller than the width of the inner liquid channel section 115, at least a portion of the inner liquid channel section 115 will have an opening in the liquid channel groove 115a that is not closed by the inner liquid channel section 125, allowing condensed liquid to enter easily and generated vapor to escape easily, thus enabling smoother movement of the working fluid.

[0200] Next, the steam channel groove 126 will be described. The steam channel groove 126 is the part through which the vaporized and condensed liquid working fluids move, and it constitutes a part of the steam channel 104. Figure 42 shows the shape of the steam channel groove 126 in plan view, and Figure 43 shows the cross-sectional shape of the steam channel groove 126.

[0201] As can be seen from these figures, the steam channel groove 126 is composed of a groove with a curved portion formed on the inner surface 120a of the main body 121, inside the ring of the annular outer peripheral liquid channel portion 124. More specifically, the steam channel groove 126 in this embodiment is a groove formed between adjacent inner liquid channel portions 125, and between the outer peripheral liquid channel portion 124 and the inner liquid channel portion 125. Furthermore, multiple (six in this embodiment) steam channel grooves 126 are arranged in directions different from the direction in which the steam channel grooves 126 extend. Accordingly, as can be seen from Figure 43, the second sheet 120 has a shape in which convex ridges are formed with the inner liquid channel portion 125 being convex, and concave ridges are formed with the steam channel groove 126 being concave, with these convex and concave shapes being repeated. Since the steam channel groove 126 is a groove, its cross-sectional shape includes a bottom and an opening located on the opposite side of the bottom.

[0202] It is preferable that the steam channel groove 126 is positioned so as to overlap in the thickness direction with the steam channel groove 116 of the first sheet 110 when combined with the first sheet 110. This allows the steam channel groove 116 and the steam channel groove 126 to form a steam channel 104. The width of the steam channel groove 126 is not particularly limited and may be the same as or different from the width of the steam channel groove 116 of the first sheet 110. In this embodiment, the width of the steam channel groove 116 and the width of the steam channel groove are the same. If the width of the steam channel groove 126 and the width of the steam channel groove 116 are different, the effect of misalignment during joining can be reduced. Furthermore, if the width of the steam channel groove 126 is made larger than the width of the steam channel groove 116, at least a portion of the inner liquid channel section 115 will have an opening in the liquid channel groove 115a that is not closed by the inner liquid channel section 125, allowing condensate to enter and steam to exit more easily, thus enabling smoother movement of the working fluid. On the other hand, the depth of the steam channel groove 126 can be considered in the same way as the steam channel groove 26 of the second sheet 20 described above.

[0203] Here, it is preferable that the steam channel groove 126 is configured such that, when combined with the first sheet 110 to form the steam channel 104, as will be explained later, the width of the steam channel 104 is greater than its height (size in the thickness direction). Therefore, the aspect ratio, which is expressed by dividing the depth of the steam channel groove 126 by the width of the steam channel groove 126, is preferably 4.0 or more, and more preferably 8.0 or more.

[0204] In this embodiment, the cross-sectional shape of the steam channel groove 126 is semi-elliptical, but it may also be a square, rectangle, trapezoid, triangle, semicircle, with a semicircular base, or with a semi-elliptical base.

[0205] The steam channel connecting groove 127 is a groove that, when combined with the steam channel connecting groove 117 of the first sheet 110, forms a channel that connects the ends of the multiple steam channels 104 formed by the steam channel groove 126. The steam channel connecting groove 127 can be considered in the same way as the steam channel connecting groove 27 of the second sheet 20 described above.

[0206] In this embodiment, the second sheet 120 includes a curved portion 128c in the outer peripheral liquid flow channel 124, the inner liquid flow channel 125, and the steam flow channel groove 126, which is a portion where the direction of extension of these changes. That is, as can be seen from Figure 42, the second sheet 120 includes a straight portion 128a in which the outer peripheral liquid flow channel 124, the inner liquid flow channel 125, and the steam flow channel groove 126 extend linearly in the x direction, a straight portion 128b in which the outer peripheral liquid flow channel 124, the inner liquid flow channel 125, and the steam flow channel groove 126 extend linearly in the y direction, and a curved portion 128c that connects the outer peripheral liquid flow channel 124, the inner liquid flow channel 125, and the steam flow channel groove 126 in the straight portions 128a and 128b. Therefore, the curved section 128c has one end connected to one straight section 128a and the other end connected to the other straight section 128b, and the outer peripheral liquid flow channel 124, the inner liquid flow channel 125, and the steam flow channel 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.

[0207] Furthermore, in the curved portion 128c of this embodiment, the configuration of the outer liquid flow channel 124, the inner liquid flow channel 125, and the steam flow channel groove 126 can be considered in the same way as the curved portion 118c of the first sheet 110 described above.

[0208] Next, the structure of the vapor chamber 101 formed by combining the first sheet 110 and the second sheet 120 will be described. This description will further explain the arrangement, size, shape, etc., of each component of the first sheet 110 and the second sheet 120. Figure 45 shows that Figure 27 has I 109 -I 109 This figure shows a cross-section of the vapor chamber 101 cut in the thickness direction along the y-direction indicated by the arrow. This figure is a combination of the figure shown in Figure 31 on the first sheet 110 and the figure shown in Figure 43 on the second sheet 120, representing the cross-section of the vapor chamber 101 in this area. Figure 46 shows I in Figure 45 110 The diagram shows a magnified view of the area indicated by the arrow. Figure 47 shows that Figure 27 has I 111 -I 111This figure shows a cross-section of the vapor chamber 101 cut in the thickness direction along the x-direction indicated by the arrow. This figure combines the figure shown in Figure 33 on the first sheet 110 and the figure shown in Figure 44 on the second sheet 120 to show the cross-section of the vapor chamber 101 in this area.

[0209] As can be seen from Figures 27, 28, and 45 to 47, the first sheet 110 and the second sheet 120 are arranged to overlap and joined together to form a 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 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 part 112 of the first sheet 110 and the injection part 122 of the second sheet 120 overlap.

[0210] The laminate of the first sheet 110 and the second sheet 120 is arranged so that the components of the main body 111 and the main body 121 are shown in Figures 45 to 47. Specifically, it is as follows.

[0211] The vapor chamber 101 of this embodiment is particularly effective when it is thin. From this viewpoint, Figures 27 and 45 show L 100 The thickness of the vapor chamber 101 shown is 1 mm or less, more preferably 0.4 mm or less, and even more preferably 0.2 mm or less. By setting the thickness to 0.4 mm or less, it becomes possible to install the vapor chamber inside the electronic device without having to perform any processing (e.g., groove formation) to create space for the vapor chamber in the electronic device where the vapor chamber 101 is installed. Furthermore, according to this embodiment, even such a thin vapor chamber can maintain thermal performance while having high strength and resistance to deformation.

[0212] On the other hand, the outer peripheral joint portion 113 of the first sheet 110 and the outer peripheral joint portion 123 of the second sheet 120 are arranged to overlap, and the two are joined by joining means such as diffusion bonding or brazing, and a working fluid is sealed inside. As a result, a sealed space 102 is formed between the first sheet 110 and the second sheet 120.

[0213] Furthermore, the outer peripheral liquid flow channel portion 114 of the first sheet 110 and the outer peripheral liquid flow channel portion 124 of the second sheet 120 are arranged to overlap. As a result, the liquid flow channel groove 114a of the outer peripheral liquid flow channel portion 114 and the outer peripheral liquid flow channel portion 124 form a condensate flow channel 103 through which the condensed liquid, which is the working fluid in a condensed and liquefied state, flows. Similarly, the inner liquid channel portion 115, which is a protrusion of the first sheet 110, and the inner liquid channel portion 125, which is a protrusion of the second sheet 120, are arranged to overlap. As a result, the liquid channel groove 115a of the inner liquid channel portion 115 and the inner liquid channel portion 125 form a condensate channel 103 through which the condensate flows.

[0214] Here, it is preferable that the cross-sectional shape of the condensate channel 103 be flattened in proportion to the thinning of the vapor chamber 101. This increases the capillary force and allows for smoother movement of the condensate, thereby maintaining a high level of heat transport capacity. More specifically, it is preferable that the aspect ratio of the condensate channel 103, which is expressed as the width divided by the height, is greater than 1.0 and 4.0 or less. In this embodiment, the width of the condensate flow path 103 is similar to the width of the liquid flow path groove 115a, but is preferably between 10 μm and 300 μm. If the width is less than 10 μm, the flow resistance will increase and the transport capacity may decrease. On the other hand, if the width is greater than 300 μm, the capillary force will decrease and the transport capacity may also decrease. Furthermore, the height of the condensate channel 103 is similar to the depth of the liquid channel groove 115a in this embodiment, but is preferably between 5 μm and 200 μm. This allows the capillary force of the condensate channel necessary for movement to be fully exerted. It is also preferable that this height is less than or equal to the thickness (wall thickness) of the first sheet 110 and the second sheet 120 on one and the other side of the condensate channel 103 in the thickness direction (z direction). This further prevents rupture (breakage) of the vapor chamber caused by the condensate channel 103.

[0215] The cross-sectional shape of the condensate channel 103 is semi-elliptical, determined by the cross-sectional shapes of the liquid channel grooves 114a and 115a. However, it is not limited to this and may be square, rectangular, trapezoidal, triangular, semicircular, with a semicircular base, with a semi-elliptical base, or a combination thereof. It can also be crescent-shaped.

[0216] In this embodiment, since the liquid channel grooves 114a and 115a are provided only in the first sheet 110, the height of the condensed liquid channel is based on the depth of the liquid channel grooves 114a and 115a. However, liquid channel grooves may also be provided in the second sheet 120. In this case, the liquid channel grooves of the first sheet and the second sheet overlap to form a condensed liquid channel, and the height of the condensed liquid channel will be in accordance with the sum of the depths of both liquid channel grooves.

[0217] By providing liquid channel grooves in the first and second sheets and stacking them in this manner, a condensed liquid channel can be constructed as shown in Figures 48 to 50. The example in Figure 48 shows that the liquid flow channel grooves of the first and second sheets are the same width and located in the same position. The example in Figure 49 shows a case where the width of the liquid channel groove in the second sheet is larger than the width of the liquid channel groove in the first sheet, but their positions coincide. In this example, a protrusion is formed in the condensate channel as indicated by P, which improves the capillary force and increases the force that moves the condensate (condensate supply force). The example in Figure 51 shows a case where the liquid channel grooves of the first and second sheets are the same width, but are positioned offset from each other. In this example as well, a protrusion is formed in the condensate channel as indicated by P, which improves the capillary force and increases the force that moves the condensate (condensate supply force).

[0218] Furthermore, as described above, communication openings 114c and 115c are formed in the condensate flow path 103. This allows multiple condensate flow paths 103 to communicate with each other, equalizing the condensate and enabling efficient movement of the condensate. In addition, the communication openings 114c and 115c, which are adjacent to the steam flow path 104 and connect the steam flow path 104 and the condensate flow path 103, allow the condensate generated in the steam flow path 104 to move smoothly to the condensate flow path 103, and the steam generated in the condensate flow path 103 to move smoothly to the steam flow path 104, thereby enabling rapid movement of the working fluid.

[0219] Furthermore, it is preferable that the condensate flow path 103 formed by the outer peripheral liquid flow path section 114 and the outer peripheral liquid flow path section 124 is formed in a continuous annular shape along the edge of the sealed space 102. That is, it is preferable that the condensate flow path 103 formed by the outer peripheral liquid flow path section 114 and the outer peripheral liquid flow path section 124 extends in an annular shape around the entire circumference without being interrupted by other components. This reduces factors that hinder the movement of the condensate, allowing the condensate to move smoothly.

[0220] In this embodiment, as described above, a condensate flow channel is formed by providing a condensate flow channel groove in the sheet, but instead, a means for generating capillary force may be separately placed here to create a condensate flow channel. For this purpose, a so-called wick, such as a mesh material, nonwoven fabric, stranded wire, or sintered metal powder, can be placed.

[0221] The opening of the steam channel groove 116 in the first sheet 110 and the opening of the steam channel groove 126 in the second sheet 120 overlap so as to face each other, forming a channel which becomes the steam channel 104. Here, it is preferable that the cross-sectional shape of the steam channel 104 be flattened in accordance with the thinning of the vapor chamber 101. This makes it possible to secure the surface area within the channel even when the channel is thinned, and to maintain a high level of heat transport capacity. More specifically, it is preferable that the aspect ratio, which is expressed as the width of the steam channel 104 divided by the height of the steam channel 104, is 2.0 or more. From the viewpoint of securing an even higher heat transport capacity, it is even more preferable that this ratio be 4.0 or more.

[0222] As can be seen in Figure 47, the opening of the steam channel communication groove 117 of the first sheet 110 and the opening of the steam channel communication groove 127 of the second sheet 120 overlap to form a channel, connecting the ends of the multiple steam channels 104 formed by the steam channel grooves 116 and 126, thus creating a channel for balanced movement of the working fluid.

[0223] As described above, the condensate flow path 103 and the vapor flow path 104 are formed in the sealed space 102 of the vapor chamber 101 by the shapes of the first sheet 110 and the second sheet 120. Figure 51 shows a diagram focusing on the condensate flow path 103 and the vapor flow path formed in the sealed space 102. As can be seen from Figures 46 and 51, the vapor chamber 101 has a shape in which multiple condensate flow paths 103 are arranged between two steam flow paths 104. This creates a configuration in which the condensate flow paths 103, through which the condensate should flow, and the steam flow paths 104, through which both steam and condensate move, are separated and arranged alternately, which helps to facilitate the smooth movement of the working fluid.

[0224] Through the steam channel 104 and the condensate channel 103, the working fluid, in the form of steam and condensate, moves through the steam channel 104, allowing for efficient heat transfer and diffusion. On the other hand, the condensate moves efficiently through the condensate channel 103, which is provided separately from the steam channel 104, by capillary force, thus suppressing the occurrence of dryout.

[0225] Furthermore, 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 when the vapor chamber is placed in electronic equipment and there are constraints on its placement that prevent the formation of a flow path consisting solely of a straight line, the curved section 107 allows the heat generated from the heat source to be efficiently moved to a position at a distance.

[0226] This curved section 107 is formed by the curved section 118c of the first sheet 110 and the curved section 128c of the second sheet 120. Thus, one end of the curved section 107 is connected to one straight section 106, and the other end is connected to the other straight section 106, and the condensate flow path 103 and the vapor flow path 104 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.

[0227] In this embodiment, the flow path cross-sectional area of ​​the steam flow path 104 belonging to the curved section 107 is configured such that the flow path cross-sectional area of ​​the steam flow path 104 located on the inside is larger than that of the steam flow path 104 located on the outside. This improves the balance of flow resistance in the curved section, making the movement of the working fluid smoother and increasing the heat transport capacity. Specifically, the flow path cross-sectional area of ​​the steam flow path can be adjusted by adjusting the size of at least one of the width and height of the flow path. Here, "channel cross-sectional area" refers to the cross-sectional area of ​​the channel in a plane perpendicular to the direction in which the channel extends.

[0228] Thus, the means, extent, and concept for increasing the cross-sectional area (width in this embodiment) of the steam flow path 104 in the curved section 107 are the same as those described in the curved section 118c of the first sheet 110 above.

[0229] Furthermore, in the curved section 107, the communication openings 114c and 115c (see Figures 34 and 36) provided in the walls 114b and 115b that separate the condensate flow path 103 and the steam flow path 104 can be configured with a different pitch than that of the straight section 106. This means that the pitch of the communication openings in the curved section may be larger or smaller than the pitch of the curved section in the straight section. The choice of configuration can be made by comprehensively considering the influence of the overall shape of the vapor chamber, the position of the heat source, etc., and adopting a configuration that can reduce flow resistance. Alternatively, in this curved section 107, it is not necessary to provide the communication openings 114c and 115c in the walls 114b and 115b that separate the condensate flow path 103 and the steam flow path 104. In a configuration where the pitch of the communication openings in the curved section is larger than that of the communication openings in the straight section, it is possible to suppress the working fluid flowing through the steam passage 104 from entering the communication openings 114c and 115c in the curved section 107. In the curved section 107, the working fluid moving through the steam passage 104 is directly subjected to a force that tries to flow into the communication openings 114c and 115c due to its flow direction, which tends to cause steam to enter the condensate passage 103 and increase the flow resistance due to the irregularities of the communication openings 114c and 115c. In contrast, by increasing the pitch of the communication openings 114c and 115c that are in contact with the steam passage 104 in the curved section 107, or by eliminating the communication openings 114c and 115c that are in contact with the steam passage 104, it is possible to suppress this increase in flow resistance, further reduce the difference in flow resistance between each steam passage 104, improve the balance of the movement of the working fluid, and increase the heat transport capacity. On the other hand, in a configuration where the pitch of the communication openings in the curved section is smaller than the pitch of the communication openings in the straight section, the steam flowing through the steam channel groove (steam channel) has more opportunities to hit the wall surface strongly in the curved section, making it more prone to condensation. In this case, by making the pitch of the communication openings in the curved section smaller than the pitch of the communication openings in the straight section, the number of communication openings can be increased, allowing the condensate to be smoothly introduced into the liquid channel groove (condensate channel), and preventing the steam channel from being blocked by the condensate. This can suppress the increase in flow resistance, further reduce the difference in flow resistance between each steam channel groove (steam channel), improve the balance of the movement of the working fluid, and in some cases increase the heat transport capacity.

[0230] Alternatively, instead of the above-mentioned pitch size, the length of the wall between adjacent communication openings in the curved section (the size in the direction along the flow path) may be configured to be larger or smaller than the length of the wall in the straight section. In this case, the length of the wall belonging to the curved section does not need to be constant and may differ from wall to wall. In this case, the relationship between the length of the wall in the curved section and the length of the wall in the straight section shall be determined by the relationship between the average values ​​of the wall lengths belonging to each section.

[0231] On the other hand, as shown in Figures 27 and 28, the inner surfaces 110a and 120a of the injection sections 112 and 122 overlap facing each other, and the opening on the opposite side of the bottom of the injection groove 122a of the second sheet 120 is closed by the inner surface 110a of the injection section 112 of the first sheet 110, forming an injection channel 105 that connects the outside with the hollow section between the main body 111 and the main body 121 (condensate channel 103 and vapor channel 104). However, after the working fluid is injected into the sealed space 102 from the injection channel 105, the injection channel 105 is closed, so in the final form of the vapor chamber 101, there is no communication between the outside and the sealed space 102.

[0232] The sealed space 102 of the vapor chamber 101 is filled with a working fluid. The type of working fluid is not particularly limited, but any working fluid commonly used in vapor chambers, such as pure water, ethanol, methanol, or acetone, can be used.

[0233] The vapor chamber 101 described above can be manufactured in the same manner as the vapor chamber 1 described above.

[0234] Next, we will explain the operation of the vapor chamber 101 when it is activated. The way in which the vapor chamber 101 is attached to the electronic device can be considered the same as the way in which it is attached as shown in Figure 23.

[0235] Figure 52 shows a diagram illustrating the behavior of the working fluid. For ease of explanation, this diagram is from the same viewpoint as Figure 51, and focuses on the condensate flow path 103 and vapor flow path 104 formed within the sealed space 102. When the electronic component 30 generates heat, that heat is transferred through the first sheet 110 by thermal conduction, and the condensate located near the electronic component 30 in the sealed space 102 receives the heat. The condensate that receives this heat absorbs the heat, evaporates, and vaporizes. This cools the electronic component 30.

[0236] The vaporized working fluid becomes steam and moves through the steam channel 104. The vaporized working fluid may move in an oscillating manner within the steam channel 104, as shown by the solid straight arrows in Figure 52, or, although not shown, it may move in one direction away from the heat source, the electronic component 30, without oscillating. In this case, the steam flow path 104 includes the curved portion of the curved section 107. However, because the curved section 107 has the above-described configuration, the balance of flow resistance is well maintained even in the curved section 107, allowing the working fluid to move smoothly through the steam flow path 104. This enables high heat transport capacity to be achieved. As the working fluid moves, it is cooled by sequentially losing heat to the first sheet 110 and the second sheet 120. The first sheet 110 and the second sheet 120, having absorbed heat from the steam, transfer that heat to their outer surfaces 110b and the casing of the portable terminal device in contact with the outer surface 120b, and finally the heat is released into the outside air. The working fluid, having lost heat while moving through the steam flow path 104, then condenses and liquefies.

[0237] A portion of the condensate generated in the steam channel 104 moves to the condensate channel 103 through a communication opening or the like. In this configuration, the condensate channel 103 is equipped with communication openings 114c and 115c, so the condensate is distributed to multiple condensate channels 103 through these communication openings 114c and 115c.

[0238] The condensate that enters the condensate channel 103 moves towards the heat source, the electronic component 30, due to the capillary force of the condensate channel, as shown by the dotted straight arrow in Figure 52. Then, it vaporizes again due to the heat from the heat source, the electronic component 30, and the above process is repeated.

[0239] As described above, the vapor chamber 101 allows for smooth and efficient movement of the working fluid in the vapor channel and high capillary force in the condensate channel, thereby increasing the heat transport capacity. Furthermore, by forming a flow path with a curved portion 107 in the vapor chamber 101, even when there are constraints on the placement of the vapor chamber when it is installed in an electronic device and it is not possible to form a flow path in a straight line only, the heat generated from the heat source can be efficiently moved to a position at a distance. Furthermore, since the curved section 107 is configured such that the difference in flow resistance between the multiple steam passages 104 is reduced, the working fluid can be moved in a balanced manner, thereby increasing the heat transport capacity.

[0240] Figures 53 to 61 illustrate a modified vapor chamber 201. Figure 53 is an external perspective view of the vapor chamber 201, and Figure 54 is an exploded perspective view of the vapor chamber 201.

[0241] As can be seen in Figures 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 together (diffusion bonding, brazing, etc.), so that a hollow space is formed between the first sheet 210 and the second sheet 220, surrounded by the first sheet 210, the second sheet 220, and the third sheet 230, and the working fluid is sealed in this hollow space to form a sealed space 202.

[0242] 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 includes 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 and forms the thickness.

[0243] The first sheet 210 comprises a main body 211 and an injection section 212. The main body 211 is a sheet-like portion that forms a sealed space through which the working fluid moves, and in this embodiment, it is a rectangle with rounded corners (so-called R) in a plan view. The injection section 212 is the part into which the working fluid is injected into the sealed space formed by the first sheet 210, the second sheet 220, and the third sheet 230. In this embodiment, it is a rectangular sheet in plan view that protrudes from the L-shape of the main body 211 in plan view. In this embodiment, both the inner surface 210a and the outer surface 210b of the injection section 212 of the first sheet 210 are flat surfaces.

[0244] 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 and forms the thickness.

[0245] The second sheet 220 also has a main body 221 and an injection section 222.

[0246] In this embodiment, the third sheet 230 is a sheet that is sandwiched and stacked between the inner surface 210a of the first sheet 210 and the inner surface 220a of the second sheet 220, and a structure for the movement of the working fluid is formed in the main body 231. Figures 55 and 56 show a plan view of the third sheet 230. Figure 55 is a view of the surface that is stacked on the second sheet 220, and Figure 56 is a view of the surface that is stacked on the first sheet 210. Also, Figure 57 shows the same as in Figure 55. 201 -I 201 The cross-section along the line indicated by the arrow, Figure 58 shows the same as in Figure 55. 202 -I 202 The cross-sections along the lines indicated are shown.

[0247] The third sheet 230 comprises a main body 231 and an injection section 232. The main body 231 is a sheet-like portion that forms a sealed space through which the working fluid moves, and in this embodiment, it is L-shaped with a curved portion in plan view. The injection section 232 is the part into which the working fluid is injected into the sealed space formed by the first sheet 210, the second sheet 220, and the third sheet 230. In this embodiment, it is a rectangular sheet in plan view that protrudes from the L-shape of the main body 231 in plan view. An injection groove 232a is formed in the injection section 232 on the side that overlaps with the first sheet 210. The injection groove 232a can be considered in the same way as the injection groove 122a described above.

[0248] The main body 231 is equipped with an outer peripheral joint portion 233, an outer peripheral liquid flow channel portion 234, an inner liquid flow channel portion 235, a steam flow channel slit 236, and a steam flow channel communication groove 237.

[0249] The outer peripheral joint portion 233 is a part formed along the outer circumference of the main body 231. One side of the outer peripheral joint portion 233 overlaps with the surface of the first sheet 210 and is joined (diffusion bonding, brazing, etc.), and the other side overlaps with the surface of the second sheet 220 and is joined (diffusion bonding, brazing, etc.). As a result, a hollow portion surrounded by the first sheet 210, the second sheet 220, and the third sheet 230 is formed, and the working fluid is sealed inside to create a sealed space. The outer periphery joint 233 can be considered in the same way as the outer periphery joint 113 described above.

[0250] The outer peripheral fluid channel section 234 functions as a fluid channel and is part of the condensed fluid channel 103, which is the channel through which the working fluid passes when it condenses and liquefies. The outer peripheral fluid channel section 234 is formed along the inside of the outer peripheral joint section 233 of the main body 231 and is provided in an annular shape along the outer circumference of the sealed space 202. A fluid channel groove 234a is formed on the surface of the outer peripheral fluid channel section 234 that faces the second sheet 220. In this embodiment, the fluid channel groove 234a is provided only on the surface that faces the second sheet 220, but a fluid channel groove may also be provided on the surface that faces the first sheet 210. The outer peripheral fluid flow channel portion 234 and the fluid flow channel groove 234a provided therein can be considered in the same way as the outer peripheral fluid flow channel portion 114 and the fluid flow channel groove 114a described above.

[0251] The inner liquid channel section 235 also functions as a liquid channel section and constitutes a part of the condensed liquid channel 103 through which the working fluid passes when it condenses and liquefies. The inner liquid channel section 235 is formed to extend with a curved portion inside the ring of the annular outer liquid channel section 234 of the main body 231. Multiple (five in this embodiment) inner liquid channel sections 235 are arranged in directions different from the direction of extension and are positioned between the steam channel slits 236.

[0252] On the side of the inner liquid flow channel 235 facing the second sheet 220, a liquid flow channel groove 235a is formed, which is a groove parallel to the direction in which the inner liquid flow channel 235 extends. The inner liquid flow channel 235 and the liquid flow channel groove 235a can be considered in the same way as the inner liquid flow channel 115 and the liquid flow channel groove 115a described above. In this embodiment, the liquid flow channel groove 235a is provided only on the side facing the second sheet 220, but in addition, a liquid flow channel groove may also be provided on the side facing the first sheet 210.

[0253] The steam flow channel slit 236 is a slit that constitutes the steam flow channel 104, and is the part through which the vaporized and condensed liquid working fluid moves. The steam flow channel slit 236 is formed on the inside of the ring of the annular outer peripheral liquid flow channel portion 234 of the main body 231, and consists of a curved slit. More specifically, the steam flow channel slit 236 in this embodiment is a slit formed between adjacent inner liquid flow channel portions 235, and between the outer peripheral liquid flow channel portion 234 and the inner liquid flow channel portion 235. Therefore, the steam flow channel slit 236 penetrates the third sheet 230 in the thickness direction (z direction). Furthermore, multiple (six in this embodiment) steam flow channel slits 236 are arranged in directions different from the direction of extension. Therefore, as can be seen from Figure 60, the third sheet 230 has a shape in which the outer peripheral liquid flow channel section 234 and the inner liquid flow channel section 235 and the steam flow channel slits 236 are alternately repeated.

[0254] Such a steam flow channel slit 236 can be considered in the same manner as the steam flow channel 104 formed by the combination of the steam flow channel groove 116 and the steam flow channel groove 126 described above.

[0255] In this embodiment, the cross-sectional shape of the steam flow channel slit 236 is formed by overlapping parts of the arcs of an ellipse, with the center in the thickness direction protruding. However, it is not limited to this, and may also be a square, rectangle, trapezoid, triangle, semicircle, crescent shape, or a combination thereof.

[0256] The steam flow channel connecting groove 237 is a groove that forms a flow channel connecting multiple steam flow channel slits 236. This allows for balancing the movement of the working fluid in the steam flow channel in the direction in which the inner liquid flow channel section 235 extends. Furthermore, this helps to equalize the working fluid in the steam flow path, transport the steam over a wider area, and efficiently utilize the condensate flow path through the numerous liquid flow path grooves 234a and 235a.

[0257] In this embodiment, the steam flow channel connecting groove 237 is formed between the outer peripheral liquid flow channel section 234 and the outer peripheral liquid flow channel section 234. The steam flow channel connecting groove 237 only needs to be able to connect adjacent steam flow channel slits 236, and its shape is not particularly limited, but it can be considered similarly to a flow channel formed by overlapping the steam flow channel connecting groove 117 and the steam flow channel connecting groove 127 described above.

[0258] The third sheet 230 also comprises straight sections 238a, 238b, and 238c, such that the condensate flow path 103 and the vapor flow path 104 have straight and curved sections within the sealed space of the vapor chamber 201. The concept of these straight and curved sections is the same as that described above.

[0259] Such a third sheet 230 can be manufactured by etching each side individually, etching both sides simultaneously, press working, or cutting.

[0260] Figures 59 to 61 illustrate the structure when the first sheet 210, the second sheet 220, and the third sheet 230 are combined to form the vapor chamber 201. Figure 59 is shown in Figure 53. 203 -I 203 Figure 60 shows a cross-section along the line indicated by the arrow, and is an enlarged view of a part of Figure 59. Also, Figure 61 shows the same cross-section as in Figure 53. 204 -I 204 This shows a cross-section along the line indicated.

[0261] As can be seen from Figure 53 and Figures 59 to 61, the first sheet 210, the second sheet 220, and the third sheet 230 are arranged and joined together to form a 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 which the liquid flow grooves 234a and 235a are not located) 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 grooves 234a and 235a are located) are arranged to face each other. Similarly, the injection sections 212, 222, and 232 of each sheet are also stacked.

[0262] As a result, a sealed space is formed between the first sheet 210 and the second sheet 220, surrounded by the first sheet 210, the second sheet 220, and the third sheet 230. A condensate flow path 103 and a vapor flow path 104 are formed in this space. The same concept as that used for the condensate flow path 103 and vapor flow path 104 of the vapor chamber 101 described above can be applied to the configuration of the condensate flow path 103 and vapor flow path 104 within this sealed space.

[0263] In the above description, a vapor chamber was described having a curved portion at the intersection where two straight sections intersect at a 90-degree angle to form an L-shape. However, the form of the curve is not limited to this, and the above-described form of the curved portion can be applied to other forms as well. For example, the above-described curved portion can be applied to the intersection of two straight sections that intersect in a T-shape, two straight sections that intersect in a cross shape, two straight sections that intersect at an acute angle (an angle smaller than 90 degrees) to form a V-shape, and two straight sections that intersect at an obtuse angle (an angle greater than 90 degrees) to form a V-shape.

[0264] [Third form] In the third embodiment, we will describe the intermediate, which is obtained during the manufacturing process of the final product, the vapor chamber; the sheet on which this intermediate is attached in multiple directions; and the roll on which this sheet is wound. For convenience, we will show the manufacturing method and explain it accordingly, while describing the structure of the obtained intermediate, the sheet on which the intermediate is attached in multiple directions; and the roll on which the intermediate is attached in multiple directions.

[0265] <<Method of manufacturing a vapor chamber S1>> Figure 62 shows the flow of a manufacturing method S301 for one form of vapor chamber (hereinafter sometimes referred to as "manufacturing method S301"). As can be seen from Figure 62, manufacturing method S301 includes the steps of manufacturing a multi-panel intermediate sheet and a multi-panel intermediate roll S310, manufacturing the intermediate S320, forming the inlet S330, injecting the liquid S340, and sealing S350. For convenience, in the following text, "sheets with multiple intermediates for vapor chambers attached" may be referred to as "multi-sided intermediate sheets," and "rolls on which sheets with multiple intermediates for vapor chambers attached are wound" may be referred to as "multi-sided intermediate rolls." The following provides a detailed explanation of each step.

[0266] <Material> Prior to manufacturing method S301, the materials are prepared. In this embodiment, the vapor chamber is manufactured by joining two sheets, so two material sheets are prepared. As explained below, in this embodiment, instead of manufacturing a vapor chamber from two material sheets in a single-sheet manner, a so-called "multi-panel" process is carried out in which two long, strip-shaped material sheets are overlapped to create a multi-panel intermediate sheet and a multi-panel intermediate roll in which multiple intermediates are arranged, and then the intermediates are individually punched out to create the vapor chamber. Therefore, the material sheets prepared in this embodiment are two long, strip-shaped sheets, and are usually provided as a roll on which these strip-shaped sheets are wound. However, this disclosure can also be applied to the manufacturing methods of intermediates and vapor chambers, which are produced on a single-wafer basis, except for processes specific to multi-panel printing.

[0267] The materials that make up the material sheet are not particularly limited, but metals can be used. Among these, metals with high thermal conductivity are preferred. Examples include copper, copper alloys, and aluminum. However, it is not necessarily limited to metallic materials; ceramics such as AlN, Si3N4, or Al2O3, or resins such as polyimide and epoxy are also possible. Furthermore, a single sheet made of two or more materials laminated together (so-called clad material, or the first sheet 10 and second sheet 20 described in vapor chamber 1) may be used, or materials with different properties may be used depending on the part.

[0268] The thickness of the material sheets can be considered in the same way as the first sheet 10 and second sheet 20 of vapor chamber 1, and the first sheet 110 and second sheet 120 of vapor chamber 101, etc.

[0269] <Manufacturing of multi-panel intermediate sheets and multi-panel intermediate rolls S310> The manufacturing process S310 for multi-panel intermediate sheets and / or multi-panel intermediate rolls (hereinafter sometimes referred to as "process S310") involves manufacturing multi-panel intermediate sheets and / or multi-panel intermediate rolls from the materials described above. Figure 63 shows the flow of process S310. As can be seen from Figure 63, process S310 includes the processes of processing S311 and joining S312.

[0270] (Processing S311) Processing S311 is a process of forming the shape for the flow path of the vapor chamber. In this embodiment, the shape is formed on one of the two material sheets, the first multi-panel sheet 301, while the other material sheet, the second multi-panel sheet 302, is used without processing for the flow path. Figure 64 shows a diagram illustrating the first multi-panel sheet 301 after processing, to which the shape 310 has been added. As can be seen from this figure, the first multi-panel sheet 301 has multiple shapes 310 for the flow path of the vapor chamber arranged on it, resulting in a sheet 301 with multiple shapes 310, and this sheet 301 is wound into a roll.

[0271] The method for forming shape 310 is not particularly limited and can include etching, cutting, and press working. Among these, etching is more efficient and suitable for mass production compared to other methods. In this case, so-called half-etching can be applied, where etching is performed only partway through the thickness direction of the material sheet without penetrating all the way through.

[0272] The specific form of shape 310 is not particularly limited here, but for example, it can take the following form. Figures 65 to 67 show diagrams illustrating one example form. Figure 65 is an external perspective view focusing on one of the polyhed shapes 310 in Figure 64. Figure 66 shows Figure 65 viewed from the z direction (plan view). Also, Figure 67 shows the same form as in Figure 66. 301 -I 301 This shows a cross-sectional view of the material after it has been cut.

[0273] The provided shape is a groove that serves as a channel for the recirculation of the working fluid, and a groove that serves as a channel for injecting the working fluid into this groove. Specifically, this embodiment includes an outer fluid channel section 314, an inner fluid channel section 315, a steam channel groove 316, a steam channel connecting groove 317, and an injection groove 318.

[0274] The outer peripheral fluid channel section 314 functions as a fluid channel section and is part of the condensed fluid channel 354 (see Figure 84, etc.), which is the second channel through which the working fluid passes when it condenses and liquefies. Figure 68 shows arrow I in Figure 67. 302 The part shown in Figure 69 is shown in Figure 66 as I 303 -I 303 The cross-section of the part that is cut is shown. The cross-sectional shape of the outer peripheral fluid flow channel 314 is shown in all figures. Also, in Figure 90, arrow I in Figure 7 304 This shows an enlarged view of a portion of the outer peripheral fluid flow channel 314 as seen from the direction indicated (z-direction, plan view).

[0275] As can be seen from these figures, the outer peripheral fluid channel section 314 is an annular section. The outer peripheral fluid channel section 314 is provided with multiple fluid channel grooves 314a that extend along the annular direction, and these multiple fluid channel grooves 314a are arranged at predetermined intervals in a direction different from the direction in which the fluid channel grooves 314a extend. Therefore, as can be seen from Figures 68 and 69, in the cross-section of the outer peripheral fluid channel section 314, the recessed fluid channel grooves 314a and the convex portions 314b between the fluid channel grooves 314a are formed in an irregular pattern. In this embodiment, as can be seen from Figure 70, adjacent fluid channel grooves 314a in the outer peripheral fluid channel section 314 are connected by communication openings 314c at predetermined intervals.

[0276] The configuration of this outer peripheral fluid channel portion 314 can be considered similarly to the outer peripheral fluid channel portion of the vapor chambers of each of the above-described configurations.

[0277] The inner liquid channel section 315 also functions as a liquid channel section and is part of the condensed liquid channel 354, which is the second channel through which the working fluid flows when it condenses and liquefies. Figure 71 shows arrow I in Figure 67. 305 The part indicated by is shown. This figure also shows the cross-sectional shape of the inner liquid flow channel 315. Also, Figure 72 shows the part indicated by arrow I in Figure 71. 306 The diagram shows an enlarged view of a portion of the inner liquid flow channel 315 as seen from the direction indicated (viewed from the z-direction, in a plan view).

[0278] As can be seen from these figures, the inner liquid channel section 315 is formed inside the annular ring of the outer liquid channel section 314. In this embodiment, the inner liquid channel section 315 is a wall extending in the x-direction, and multiple (three in this embodiment) inner liquid channels are arranged at predetermined intervals in a direction perpendicular to the direction of extension (y-direction). Each inner liquid flow channel section 315 has a liquid flow channel groove 315a formed in it, which is a groove parallel to the direction in which the inner liquid flow channel section 315 extends. Multiple liquid flow channel grooves 315a are arranged at predetermined intervals in a direction different from the direction in which the liquid flow channel grooves 315a extend. Therefore, as can be seen from Figures 67 and 71, in the cross-section of the inner liquid flow channel section 315, the recessed liquid flow channel grooves 315a and the convex portions 315b between the liquid flow channel grooves 315a are formed in an alternating pattern of concave and concave. Furthermore, as can be seen from Figure 72, adjacent liquid flow channel grooves 315a are connected by communication openings 315c at predetermined intervals.

[0279] The configuration of this internal liquid flow channel 315 can be considered similarly to the internal liquid flow channel of the vapor chambers of each of the above-described configurations.

[0280] The steam channel groove 316 is the section through which the vaporized steam from the evaporation of the working fluid passes, and it constitutes a part of the first channel, the steam channel 355 (see Figure 84, etc.). Figure 66 shows the shape of the steam channel groove 316 as viewed from the z direction, and Figure 67 shows the cross-sectional shape of the steam channel groove 316.

[0281] As can be seen from these figures, the steam channel groove 316 is composed of a groove formed on the inside of the annular ring of the outer liquid channel section 314. More specifically, the steam channel groove 316 in this embodiment is formed between adjacent inner liquid channel sections 315, and between the outer liquid channel section 314 and the inner liquid channel section 315, and extends in the direction in which the inner liquid channel section 315 extends (x direction). Multiple (four in this embodiment) steam channel grooves 316 are arranged in a direction perpendicular to the direction of extension (y direction). Therefore, as can be seen from Figure 67, in the y direction, the shape has repeating irregularities, with the outer liquid channel section 314 and the inner liquid channel section 315 having convex ridges and the steam channel groove 316 having concave ridges.

[0282] The shape of this steam channel groove 316 can be considered similar to the steam channel grooves of the vapor chambers of each of the above-described forms.

[0283] The steam channel connecting groove 317 is a groove that connects multiple steam channel grooves 316. This allows for the equalization of steam in multiple steam channel grooves 355, and enables the steam to be carried over a wider area, allowing for the efficient use of many condensate channel grooves 354, thereby making the recirculation of the working fluid smoother. The shape of the steam flow channel communication groove 317 can be considered similar to the steam flow channel communication groove of each of the vapor chambers described above.

[0284] The injection groove 318 is a groove that injects the working fluid into the steam flow channel groove 316. As can be seen from Figures 65 and 66, in this embodiment, the injection groove 318 is a groove that crosses the outer peripheral liquid flow channel section 314 and is connected to the steam flow channel communication groove 317.

[0285] (Joint S312) In joining S312 shown in Figure 63, the first multi-panel sheet 301 and the second multi-panel sheet 302 prepared in processing S311 as described above are overlapped and joined to produce a multi-panel intermediate sheet 350 and a multi-panel intermediate roll 351 formed by winding this sheet. The joining method is not particularly limited and can include diffusion bonding, brazing, irradiation, etc. Here, we will explain joining by irradiation as one example. A diagram for explanation is shown in Figure 73. In this embodiment, all of these joining processes are performed in a vacuum chamber 360 connected to a vacuum pump (not shown).

[0286] The first multi-up sheet 301 and the second multi-up sheet 302 are unwound from the roll.

[0287] Next, at least one of an atomic beam, an ion beam, and a plasma is irradiated from the irradiation device 361 onto the side of the unwound multi-faceted first sheet 301 on which the above-described shape 310 is formed. Here, the atomic beam being irradiated refers to a collection of neutral atoms traveling as a thin beam in a specific direction, the ion beam refers to ions accelerated by an electric field, and the plasma refers to a state in which the molecules constituting a gas are ionized and separated into positive ions and electrons that are in motion. This removes the oxide film from the irradiated surface of the first multi-faceted sheet 301.

[0288] Similarly, at least one of an atomic beam, an ion beam, and a plasma is irradiated from the irradiation device 362 onto the side of the unwound poly-faced second sheet 302 that is superimposed on the poly-faced first sheet 301. This removes the oxide film from the irradiated surface of the multi-faceted second sheet 302.

[0289] As described above, the surfaces of the first multi-panel sheet 301 and the second multi-panel sheet 302, which have been irradiated, are overlapped and pressed together by the pressing roll 363. This joins the first multi-panel sheet 301 and the second multi-panel sheet 302 together, forming a multi-panel intermediate sheet 350. This multi-panel intermediate sheet 350 is then wound up to form a multi-panel intermediate roll 351.

[0290] In this way, by irradiating the bonding surfaces of the sheets to be joined as described above before bonding, the oxide film is removed, eliminating the need for bonding at high temperatures, and thus suppressing material degradation. In particular, as the vapor chamber becomes thinner, such material degradation can easily cause problems such as poor sealing of the working fluid, so this method can suppress the occurrence of such problems. Furthermore, in addition to removing the oxide film on the joint surface, the oxide film on the inside of the liquid channel groove 314a, liquid channel groove 315a, steam channel groove 316, and steam channel connecting groove 317 can also be removed, thereby improving the wettability of the inner surface and enhancing the heat transport performance of the vapor chamber.

[0291] Furthermore, this oxide film removal effect, and the resulting improvement in heat transport performance, can also be observed in diffusion bonding and brazing.

[0292] Figure 74 shows the appearance of the multi-panel intermediate sheet 350 and the multi-panel intermediate roll 351. In Figure 74, shape 310 is positioned between the first multi-panel sheet 301 and the second multi-panel sheet 302 and is not visible from the outside, so it is represented by a dotted line. Figure 75 shows a cross-section of the portion of the multi-paneled intermediate sheet 350 that corresponds to one of the multi-paneled shapes 310. This cross-section is viewed from the same perspective as Figure 67.

[0293] As can be seen from these figures, in the multi-panel intermediate sheet 350 and the multi-panel intermediate roll 351, the openings of the liquid flow channel groove 314a, liquid flow channel groove 315a, steam flow channel groove 316, and steam flow channel connecting groove 317 are closed by the multi-panel second sheet 302, forming a hollow section. In this embodiment, the oxygen concentration inside the hollow section is configured to be 1% or less. Preferably, it is 0.1% or less, and more preferably 500 ppm or less. This hollow section is isolated from the outside and does not communicate with the outside of the multi-panel intermediate sheet 350 and the multi-panel intermediate roll 351, thus maintaining this oxygen concentration. According to this, even when the multi-panel intermediate sheet 350 and multi-panel intermediate roll 351 are stored and transported, and not immediately processed into a vapor chamber, the oxygen concentration inside the hollow section can be kept low, thereby suppressing the formation of an oxide film on the inner surface of the hollow section. Therefore, even when a vapor chamber is subsequently manufactured using this multi-panel intermediate sheet 350, there is less oxide film on the inner surface of the flow channels (condensate flow channel 354, vapor flow channel 355), making it possible to produce a vapor chamber with good heat transport performance.

[0294] One way to achieve this is to create a vacuum inside the hollow section. Here, "vacuum" does not necessarily mean a perfect vacuum; for example, it would suffice to set the pressure to 134 Pa or less (1 Torr or less).

[0295] There are no particular limitations on the method for creating a vacuum inside the hollow section, but for example, when joining the multi-panel first sheet 301 and the multi-panel second sheet 302 as described above, it is possible to do so in a vacuum atmosphere. Not only the irradiation joining described above, but also diffusion joining and brazing joining can be done in a vacuum atmosphere.

[0296] Furthermore, although this embodiment describes an example in which the hollow portions of the multi-panel intermediate sheet 350 and the multi-panel intermediate roll 351 are in a vacuum state, it is sufficient to suppress the formation of an oxide film on the inner surface of the hollow portion by suppressing the oxygen concentration. Instead of a vacuum state, the hollow portion may be configured to contain an inert gas such as nitrogen or argon. This also suppresses the oxygen concentration in the hollow portion and suppresses the formation of an oxide film. In this case as well, by performing the joining using a joining method that allows joining in an inert gas atmosphere, it is possible to include the inert gas within the hollow portion.

[0297] Furthermore, moisture may be present within the hollow portion.

[0298] Furthermore, even if the hollow section contains air and the oxygen concentration is greater than 1%, the formation of an oxide film is suppressed compared to when the hollow section is in contact with the outside, because the hollow section is isolated from the outside as described above and there is no exchange of air. Therefore, although to varying degrees, adopting a configuration in which air is contained in the hollow section will produce the above-mentioned effects.

[0299] <Intermediate production S320> In the intermediate manufacturing process S320 shown in Figure 62, an intermediate 352 is manufactured from a multi-panel intermediate sheet 350 and a multi-panel intermediate roll 351. Specifically, the intermediate 352 is extracted from the multi-panel intermediate sheet 350, which has multiple layers of material that will become the intermediate 352 attached to it, using known methods such as punching out individual intermediates 352. Figure 76 shows an external perspective view of the intermediate body 352, and Figure 77 shows a view of the intermediate body 352 from the z direction (plan view). In Figure 77, the shape of the hollow portion formed inside the intermediate body 352 is shown by a dotted line.

[0300] As can be seen from Figures 76 and 77, even in the intermediate 352, the hollow portion is isolated from the outside. This suppresses the formation of an oxide film on the inner surface of the hollow portion even in the intermediate 352 state. Therefore, in this embodiment, the intermediate 352 may be stored and transported.

[0301] Figure 77 shows W 301 The width of the joint shown can be set 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 2.0 mm or less. 301 If the width W becomes larger than 3.0 mm, the internal volume of the space for the fluid passage will decrease, and there is a risk that the steam passage and condensate passage will not be sufficiently secured. 301 The width W is preferably 0.2 mm or more, may be 0.6 mm or more, or 0.8 mm or more. 301 If the width becomes smaller than 0.2 mm, there is a risk that the bonding area will be insufficient when misalignment occurs during the joining of the first and second sheets. 301 The range may be determined by a combination of any one of the above multiple candidate upper limits and one of the multiple candidate lower limits. Also, the width W 301 The range may be determined by any two combinations of multiple candidate upper bounds, or any two combinations of multiple candidate lower bounds.

[0302] <Formation of the inlet S330> In the injection port formation S330 shown in Figure 62, an opening is formed in the hollow portion for injecting the working fluid. Therefore, in this embodiment, an opening is formed in the intermediate body 352 that communicates with the injection groove 318 from the outside. Figures 78 and 79 show the configuration of the injection port 319 according to one example, and Figures 80 and 81 show the configuration of the injection port 319 according to another example.

[0303] In the examples shown in Figures 78 and 79, an injection port 319 is formed by drilling a hole in the intermediate body 352 in the z direction (thickness direction), thereby connecting the injection groove 318 to the outside. In contrast, in the example shown in Figures 80 and 81, the end face of the intermediate body 352 is removed to form the injection port 319, thereby connecting the injection groove 318 to the outside.

[0304] In this embodiment, an inlet is made in the intermediate 352. However, if the intermediate is stored and transported in a multi-panel intermediate sheet 350 or a multi-panel intermediate roll 351, and the vapor chamber is to be made immediately after removing the intermediate 352, an inlet 319 may be formed in the multi-panel intermediate sheet 350 before it becomes the intermediate 352. Therefore, in this case, the inlet 319 will be formed before or simultaneously with the removal of the intermediate 352.

[0305] <Injection S340> In the fluid injection S340 shown in Figure 62, the working fluid is injected into the hollow section using the formed injection port 319. The injection method is not particularly limited, and known methods can be applied.

[0306] The type of working fluid is not particularly limited, but any working fluid commonly used in vapor chambers, such as pure water, ethanol, methanol, acetone, and mixtures thereof, can be used.

[0307] <Sealing S350> In sealing S350, the injection groove 318 is closed while the working fluid is injected. The method of closing is not particularly limited, but examples include crimping and welding.

[0308] [Vapor Chamber] The vapor chamber 353 manufactured as described above has the following configuration. Figures 82 to 84 show diagrams for explanation. Figure 82 is an external perspective view of the vapor chamber 353, Figure 83 is a view of the vapor chamber 353 from the z direction, and Figure 84 is a view of Figure 83 with an I307 -I 307 It is a cross-sectional view along the line shown in FIG. In FIG. 83, the inner structure is represented by a dotted line.

[0309] The inside of the vapor chamber 353 is a sealed space by enclosing a working fluid in the hollow portion of the intermediate body 352. Specifically, this sealed space includes a condensate flow path 354 which is a second flow path through which condensate, in a state where the working fluid is condensed and liquefied, flows along the liquid flow path grooves 314a and 315a, and a vapor flow path 355 which is a first flow path through which vapor, in a state where the working fluid is condensed and vaporized, flows along the vapor flow path groove 316. Further, this sealed space also includes a flow path that connects the vapor flow path 355 through the vapor flow path communication groove 317. Thus, since the condensate flow path 354 which is the second flow path is formed separately from the vapor flow path 355 which is the first flow path, the circulation of the working fluid can be made smooth. Also, by forming the condensate flow path 354 into a narrow flow path surrounded by walls on all four sides in cross-section, the condensate can be moved by a strong capillary force, enabling smooth circulation.

[0310] Here, the flow path cross-sectional area of the condensate flow path 354 which is the second flow path is made smaller than the flow path cross-sectional area of the vapor flow path 355 which is the first flow path. More specifically, taking the average flow path cross-sectional area of two adjacent vapor flow paths 355 (in this embodiment, the vapor flow path 355 formed by one vapor flow path groove 316) as A g and the average flow path cross-sectional area of a plurality of condensate flow paths 354 (in this embodiment, the plurality of condensate flow paths 354 formed by one inner liquid flow path portion 315) arranged between two adjacent vapor flow paths 355 as A l when, the condensate flow path 354 and the vapor flow path 355 are such that A l is 0.5 times or less of A g and preferably 0.25 times or less. Thereby, the working fluid becomes more likely to selectively pass through the first flow path and the second flow path depending on its phase state (gas phase, liquid phase). This relationship only needs to be satisfied in at least a part of the entire vapor chamber, and it is more preferable if this is satisfied throughout the entire vapor chamber.

[0311] Such a vapor chamber 353 can be attached to and operated by an electronic device, just like the other forms of vapor chambers described above. In this embodiment, as described above, during the manufacturing process, a state is maintained in which an oxide film is less likely to form on the inner surface of the hollow parts (condensate flow path 354, steam flow path 355) in the multi-pane intermediate sheet 350, the multi-pane intermediate roll 351, and the intermediate 352. As a result, the wettability of the inner surface of the condensate flow path 354 and the steam flow path 355 is good, which enhances the smooth flow of the working fluid and heat transfer. In particular, in embodiments like the present one, which aim to obtain high heat transport capacity by thinning the vapor chamber while increasing the internal surface area of ​​the flow path to enlarge the heat transfer area, the influence of the oxide film becomes relatively large. Therefore, the effect of exhibiting high heat transport capacity by implementing the method described in this disclosure is remarkable.

[0312] In this embodiment, an example is shown in which liquid flow channel grooves 314a, liquid flow channel grooves 315a, and steam flow channel grooves 316 are provided only on the multi-panel first sheet 301. However, as shown in Figure 85, steam flow channel grooves 326 may also be provided on the multi-panel second sheet 302, and as shown in Figure 86, liquid flow channel grooves 324a, liquid flow channel grooves 325a, and steam flow channel grooves 326 may also be provided on the multi-panel second sheet 302. In this example, the multi-panel intermediate sheet, multi-panel intermediate roll, intermediate, and vapor chamber described herein can also be used.

[0313] Furthermore, the configuration is not limited to two multi-panel sheets, but may also consist of a multi-panel intermediate sheet, a multi-panel intermediate roll, an intermediate manufactured therefrom, and a vapor chamber, as shown in Figure 87, comprising three multi-panel sheets.

[0314] The multi-panel intermediate sheet shown in Figure 87 is a laminate of a first multi-panel sheet 301, a second multi-panel sheet 302, and a multi-panel intermediate sheet 303 (third multi-panel sheet 303). The multi-panel intermediate sheet 303 is positioned between the first multi-panel sheet 301 and the second multi-panel sheet 302, and each is joined together in accordance with the example described above.

[0315] In this example, both sides of the first multi-panel sheet 301 and the second multi-panel sheet 302 are flat. In this case, the thickness of the first multi-panel sheet 301 and the second multi-panel sheet 302 is preferably 1.0 mm or less, may be 0.5 mm or less, or 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 0.030 mm or more. This thickness range may be determined by a combination of any one of the above-mentioned upper limit candidate values ​​and one of the above-mentioned lower limit candidate values. Furthermore, this thickness range may be determined by a combination of any two of the above-mentioned upper limit candidate values, or a combination of any two of the above-mentioned lower limit candidate values.

[0316] The multi-faceted intermediate sheet 303 is equipped with a steam channel groove 336, an outer liquid channel section 334, an inner liquid channel section 335, a liquid channel groove 334a, and a liquid channel section 335a. The steam channel groove 336 is a groove that penetrates the multi-faceted intermediate sheet 303 in the thickness direction, and is similar to the groove that constitutes the first channel, the steam channel 355, with the steam channel groove 316 described above, and is arranged in a corresponding manner. The outer peripheral liquid flow channel section 334 and the liquid flow channel groove 334a can be considered in the same way as the outer peripheral liquid flow channel section 314 and the liquid flow channel groove 314a described above, and the outer peripheral liquid flow channel section 335 and the liquid flow channel groove 335a can be considered in the same way as the outer peripheral liquid flow channel section 315 and the liquid flow channel groove 315a described above.

[0317] The examples of each form described herein are not limited to those described herein, and their components may be modified and materialized without departing from the gist of the disclosure. Furthermore, various forms can be created by appropriately combining the multiple components disclosed in the above forms. Some components may be deleted from all the components shown in each form. [Explanation of Symbols]

[0318] 1.101 Vapor Chamber 2, 102 Closed space 3, 103 Condensate flow path 4, 104 Steam channel 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 channel grooves 17, 117 Steam flow channel connecting groove 20, 120 Second seat 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 channel grooves 27, 127 Steam flow channel connecting groove 30 Electronic Components 40. Electronic devices (portable terminals) 41 cabinets 50, 230 Third Seat 236 Steam flow channel slit 301 Multi-sided first sheet 302 Multi-sided second sheet 350 multi-faceted intermediate sheets 351 Multi-faceted intermediate roll 352 Intermediates 353 Vapor Chamber

Claims

1. A main body sheet for a vapor chamber in which a working fluid is sealed, The first main surface and It comprises a second body surface located on the opposite side from the first body surface, The first main body surface has a plurality of flow channels, A layer having grooves that serve as flow channels, A layer is laminated inside the groove and forms the inner surface of the flow path, The inner surface layer of the aforementioned channel is made of copper or a copper alloy. The 0.2% proof stress or upper yield point of the layer having the groove is greater than the 0.2% proof stress or upper yield point of the layer forming the inner surface of the flow path. Main sheet for vapor chamber.

2. The flow path includes a condensate flow path through which the working fluid moves in a condensate state, The system includes a vapor channel through which the working fluid moves in the form of vapor and condensate, The condensate flow path and the vapor flow path are adjacent in a plan view. The main body sheet for a vapor chamber according to claim 1.

3. The main body sheet for a vapor chamber according to claim 2, wherein the vapor passage extends from the first main body surface of the main body sheet to the second main body surface and penetrates through it.

4. The main body sheet for a vapor chamber according to any one of claims 1 to 3, wherein the grooved layer is not exposed from the inner surface layer of the flow path at least at the location where the grooves are provided.

5. The main body sheet for a vapor chamber according to any one of claims 1 to 4, wherein the grooved layer has a different thickness in the portion having the groove and the portion not having the groove.

6. The main body sheet for a vapor chamber according to any one of claims 1 to 5, wherein the thickness of the layer forming the inner surface of the flow path is 5 μm or more and 20 μm or less.

7. The main body sheet for a vapor chamber according to any one of claims 1 to 6, wherein the material of the grooved layer is an iron-based material such as stainless steel, invar, or Kovar, a titanium alloy, or a nickel alloy.

8. The main body sheet for a vapor chamber according to claim 7, wherein the grooved layer contains fine particles such as diamond, alumina, or silicon carbide.

9. A main sheet according to any one of claims 1 to 8, The system comprises a first sheet laminated on the first main body surface of the main body sheet, Vapor chamber.

10. In a plan view, between adjacent flow channels, a protrusion is provided that projects toward the first sheet. The aforementioned protrusion is in contact with the surface of the first sheet that is on the main sheet side. The vapor chamber according to claim 9.

11. A vapor chamber comprising the vapor chamber described in claim 9 or claim 10, electronic equipment.

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