Vapor chamber

Abstract

To provide a vapor chamber capable of improving a heat transport capability.SOLUTION: A vapor chamber includes: a first face; a second face on the opposite side to the first face; a second flow path disposed on the first face; and a first flow path disposed so as to penetrate from the first face to the second face.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

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

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

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

[0005] More specifically, the vapor chamber contains a vapor flow path and a condensate flow path, and the working fluid is sealed inside. When the vapor chamber is placed next to a heat source, the working fluid near the heat source receives heat from the heat source and evaporates, becoming a gas (vapor) that travels down the vapor flow path. This allows the heat from the heat source to be smoothly transported to a location away from the heat source, resulting in cooling of the heat source. The gaseous working fluid that transports heat from the heat source moves to a position away from the heat source, where it is cooled and condensed as heat is absorbed by the surroundings, changing into a liquid state. The liquid working fluid passes through the condensate flow path, returns to the heat source, and absorbs heat from the heat source again, evaporating and changing into a gaseous state. By circulating the heat generated from the heat source in this manner, it is transported and diffused to a location away from the heat source, thereby cooling the heat source. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-212028 Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure provides a vapor chamber that can enhance heat transport capacity. [Means for solving the problem]

[0008] One aspect of the present disclosure is a sheet for a vapor chamber in which a working fluid is sealed in an enclosed space, the sheet for the vapor chamber having a first surface and a second surface opposite the first surface, the sheet having a second flow path provided on the first surface and a first flow path provided through the first surface to the second surface of the sheet, the second flow path being connected to the first flow path via a wall surface of the first flow path by a plurality of communicating openings, the wall surface having an apex that protrudes most toward the inside of the first flow path, and the wall surface being inclined from the apex toward the first surface in a cross-sectional view. [Effects of the Invention]

[0009] According to the present disclosure, the heat transport capacity of the vapor chamber can be increased. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of the vapor chamber 1. FIG. [Figure 2] FIG. 2 is an exploded perspective view of the vapor chamber 1. FIG. [Figure 3] FIG. 3 is a view of the third sheet 30 as seen from the z direction. [Figure 4] FIG. 4 is a view seen from the opposite side to FIG. [Figure 5] FIG. 5 is a cross-sectional view of the third sheet 30. [Figure 6] FIG. 6 is another cross-sectional view of the third sheet 30. As shown in FIG. [Figure 7] 7(a) and 7(b) are cross-sectional views focusing on the outer peripheral liquid flow path section 34. FIG. [Figure 8] FIG. 8 is an enlarged view of a part of the outer peripheral liquid flow path section 34 as viewed from the z direction. [Figure 9] FIG. 9 is a partially enlarged view of another example of the outer peripheral liquid flow path portion as viewed from the z direction. [Figure 10] FIG. 10 is a diagram illustrating another example of the outer peripheral liquid flow path portion. [Figure 11] FIG. 11 is a diagram illustrating another example of the outer peripheral liquid flow path portion. [Figure 12] FIG. 12 is a diagram illustrating another example of the outer peripheral liquid flow path portion. [Figure 13] 13(a) and 13(b) are cross-sectional views focusing on the inner liquid flow path section 38. FIG. [Figure 14] FIG. 14 is an enlarged view of a part of the inner liquid flow path section 38 as viewed from the z direction. [Figure 15] FIG. 15 is a cross-sectional view of the vapor chamber 1. [Figure 16] FIG. 16 is another cross-sectional view of the vapor chamber 1. [Figure 17] 17(a) and 17(b) are enlarged cross-sectional views of a part of FIG. [Figure 18] 18(a) and 18(b) are enlarged cross-sectional views of a part of FIG. [Figure 19] FIG. 19 is a diagram illustrating an electronic device 50. As shown in FIG. [Figure 20]FIG. 20 is a diagram illustrating the flow of the working fluid. [Figure 21] FIG. 10 is a diagram illustrating an example using four sheets. [Figure 22] FIG. 22 is an exploded perspective view of the vapor chamber 51 according to the second embodiment. [Figure 23] FIG. 23 is a diagram illustrating the sealed space of the vapor chamber 51. [Figure 24] FIG. 24 is a cross-sectional view of the vapor chamber 51. [Figure 25] FIG. 25 is an enlarged view of a part of FIG. [Figure 26] FIG. 26 is a perspective view of the vapor chamber 101. [Figure 27] FIG. 27 is an exploded perspective view of the vapor chamber 101. [Figure 28] FIG. 28 is a view of the third sheet 130 as seen from the z direction. [Figure 29] FIG. 29 is a view seen from the opposite side to FIG. [Figure 30] FIG. 30 is a cross-sectional view of the third sheet 130. [Figure 31] FIG. 31 is another cross-sectional view of the third sheet 130. [Figure 32] FIG. 32 is a cross-sectional view focusing on the outer peripheral liquid flow path section 134. [Figure 33] FIG. 33 is a diagram illustrating the outer peripheral liquid flow path section 134. [Figure 34] FIG. 34 is a cross-sectional view of the area where the pillar 136a is arranged. [Figure 35] FIG. 35 is a cross-sectional view focusing on the inner liquid flow path section 138. [Figure 36] FIG. 36 is a diagram illustrating the inner liquid flow path section 138. [Figure 37] FIG. 37 is a cross-sectional view of the area where the pillar 140a is arranged. [Figure 38] FIG. 38 is a cross-sectional view of the vapor chamber 101. [Figure 39] FIG. 39 is another cross-sectional view of the vapor chamber 101. [Figure 40]FIG. 40 is an enlarged view of a part of FIG. [Figure 41] FIG. 41 is an enlarged cross-sectional view of the area where the pillar 136a is arranged. [Figure 42] FIG. 42 is an enlarged view of a part of FIG. [Figure 43] FIG. 43 is an enlarged cross-sectional view of the area where the pillar 140a is arranged. [Figure 44] FIG. 44 is a diagram illustrating another embodiment. [Figure 45] FIG. 45 is a diagram illustrating another embodiment. [Figure 46] FIG. 46 is a diagram illustrating another embodiment. [Figure 47] FIG. 47 is a diagram illustrating another embodiment. [Figure 48] 48(a) and 48(b) are cross-sectional views focusing on the inner liquid flow path section 238. FIG. [Figure 49] 49(a) and 49(b) are cross-sectional views of the vapor chamber 201, showing the periphery of the inner liquid flow path portion 238. FIG. [Figure 50] FIG. 50 is a diagram illustrating a preferred embodiment in cross section. [Figure 51] 51(a) and 51(b) are diagrams for explaining other types of introduction portions. [Figure 52] 52(a) and 52(b) are diagrams for explaining other types of introduction portions. [Figure 53] 53(a) and 53(b) are diagrams for explaining other types of introduction portions. [Figure 54] 54(a) and 54(b) are diagrams for explaining other types of introduction portions. [Figure 55] 55(a) and 55(b) are diagrams for explaining other types of introduction portions. [Figure 56] 56(a) and 56(b) are diagrams for explaining other types of introduction portions. [Figure 57] 57(a) and 57(b) are diagrams for explaining other types of introduction portions. [Figure 58] FIG. 58 is a cross-sectional view of the vapor chamber 301. [Figure 59] FIG. 59 is a diagram illustrating the manufacturing process of the vapor chamber 301. [Figure 60] FIG. 60 is a diagram illustrating the manufacturing process of the vapor chamber 301. [Figure 61] FIG. 61 is a diagram illustrating the manufacturing process of the vapor chamber 301. [Figure 62] FIG. 62 is a diagram illustrating the manufacturing process of the vapor chamber 301. [Figure 63] FIG. 63 is a diagram illustrating the manufacturing process of the vapor chamber 301. [Figure 64] FIG. 64 is a diagram illustrating the manufacturing process of the vapor chamber 301. [Figure 65] FIG. 65 is a cross-sectional view of the vapor chamber 301'. [Figure 66] FIG. 66 is a cross-sectional view of vapor chamber 301″. [Figure 67] FIG. 67 is a cross-sectional view of the vapor chamber 401. [Figure 68] FIG. 68 is a diagram illustrating the inner liquid flow path portion 538 in the vapor chamber 501. [Figure 69] FIG. 69 is a diagram for explaining the shape of the pair of liquid flow path convex portions shown in FIG. [Figure 70] FIG. 70 is a diagram for explaining the function of the pair of liquid flow path protrusions shown in FIG. [Figure 71] FIG. 71 is a diagram for explaining the actual shape of the liquid flow path convex portion shown in FIG. [Figure 72] FIG. 72 is a diagram illustrating an inner liquid flow path portion 538' in the vapor chamber 501'. [Figure 73] FIG. 73 is a diagram illustrating an inner liquid flow path portion 538″ in a vapor chamber 501″. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure will be described below based on the embodiments shown in the drawings. In the drawings shown below, the size and proportions of components may be changed or exaggerated for clarity. In addition, for clarity, parts not required for explanation and repeated reference numerals may be omitted. Furthermore, terms used in this specification that specify shapes, geometric conditions, physical properties, and their degrees, such as "parallel," "orthogonal," and "identical," as well as lengths, angles, and physical property values, are not limited to their strict meanings but are interpreted to include the range within which similar functions can be expected. Furthermore, in the drawings, for clarity, the shapes of multiple parts that can be expected to have similar functions are depicted in a regular pattern. However, the shapes of these parts may differ from each other as long as the functions can be expected without being limited to strict meanings. Furthermore, in the drawings, boundaries indicating the joining surfaces between components are shown as simple straight lines for convenience. However, these boundaries are not required to be strictly straight lines, and the shape of the boundaries is arbitrary as long as the desired joining performance can be expected.

[0012] 1. Form 1 1.1.Form 1a [Components] Fig. 1 shows an external perspective view of the vapor chamber 1 according to form 1a, and Fig. 2 shows an exploded perspective view of the vapor chamber 1. For convenience, these figures and the figures shown below also show arrows (x, y, z) indicating directions corresponding to a three-dimensional Cartesian coordinate system, as needed. Here, the xy in-plane direction is the plate surface direction of the plate-shaped vapor chamber 1, and the z direction is the thickness direction.

[0013] As can be seen from Figures 1 and 2, the vapor chamber 1 of this embodiment has a first sheet 10, a second sheet 20, and a third sheet 30 (sometimes referred to as "intermediate sheet 30"). As will be explained later, these sheets are stacked and joined (by diffusion bonding, brazing, etc.) to form a vapor chamber sheet in which a hollow space based on the shape of the third sheet 30 is formed between the first sheet 10 and the second sheet 20. A working fluid is then sealed in this hollow space to form a sealed space 2 (see Figure 15, for example), which becomes the vapor chamber 1.

[0014] <First sheet> In this embodiment, the first sheet 10 is a sheet-like member having flat front and back surfaces (one surface and the other surface in the thickness direction, the inner surface 10a and the outer surface 10b). The first sheet 10 is composed of flat front and back surfaces, and has a flat inner surface 10a, a flat outer surface 10b opposite the inner surface 10a, and an end surface 10c that spans the inner surface 10a and the outer surface 10b to form a thickness.

[0015] The first sheet 10 also includes a main body 11 and an injection portion 12 . The main body 11 is a sheet-like portion that forms a hollow portion and an enclosed space, and in this embodiment is a rectangle with arcuate corners (so-called R-shaped) in plan view. However, the main body 11 of the first sheet 10 may have a shape other than the rectangular shape of this embodiment that is required for the vapor chamber. For example, it may have a circular, elliptical, triangular, or other polygonal shape, as well as a shape with a bent portion, such as an L-shape, a T-shape, a crank shape, or a U-shape. It may also have a shape that combines at least two of these shapes.

[0016] The injection portion 12 is a portion where the working fluid is injected into the formed hollow portion, and in this embodiment, is in the form of a rectangular sheet in plan view that protrudes from one side of the main body 11 that is rectangular in plan view.

[0017] The thickness of the first sheet 10 is not particularly limited, but is preferably 1.0 mm or less, and may be 0.75 mm or less, or 0.5 mm or less. On the other hand, the thickness is preferably 0.01 mm or more, and may be 0.05 mm or more, or may be 0.1 mm or more. This thickness range may be determined by combining any one of the multiple upper limit candidate values ​​and any one of the multiple lower limit candidate values. Furthermore, this thickness range may be determined by combining any two of the multiple upper limit candidate values, or any two of the multiple lower limit candidate values. This makes it possible to increase the number of situations in which it can be used as a thin vapor chamber.

[0018] The material constituting the first sheet 10 is not particularly limited, but is preferably a metal with high thermal conductivity. Examples of such materials include copper and copper alloys. However, the material does not necessarily have to be a metal; other materials include ceramics such as AlN, Si3N4, or Al2O3, and resins such as polyimide and epoxy. Furthermore, a sheet may be used in which two or more types of materials are laminated within one sheet, or different materials may be used depending on the location.

[0019] The first sheet 10 may be a single layer or may be formed by laminating a plurality of sheets. For example, a sheet (clad material) in which a plurality of layers with different strengths are laminated may be used.

[0020] <Second sheet> In this embodiment, the second sheet 20 is also a sheet-like member having flat front and back surfaces. The second sheet 20 is composed of flat surfaces on both the front and back sides, and has a flat inner surface 20a, a flat outer surface 20b opposite the inner surface 20a, and an end surface 20c that spans the inner surface 20a and the outer surface 20b to form a thickness. Similarly to the first sheet 10, the second sheet 20 also has a main body 21 and an injection portion 22. Otherwise, the second sheet 20 can be considered to be similar to the first sheet 10. However, the thickness and material of the second sheet 20 do not need to be the same as those of the first sheet 10, and may be configured to be different.

[0021] The second sheet 20 may also be a single layer, or may be formed by laminating a plurality of sheets. For example, a sheet (clad material) in which a plurality of layers with different strengths are laminated may be used.

[0022] <Third sheet> In this embodiment, the third sheet 30 is a sheet that is sandwiched and stacked between the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20, and is provided with a structure for the sealed space 2 through which the working fluid moves. 3 and 4 show plan views (viewed from the z direction) of the third sheet 30. Fig. 3 shows the surface that is superimposed on the first sheet 10, and Fig. 4 shows the surface that is superimposed on the second sheet 20. Also, Fig. 5 shows a cross-sectional view taken along the line C1-C1 in Fig. 3, and Fig. 6 shows a cross-sectional view taken along the line C2-C2 in Fig. 3. In the cross-sectional views, portions related to the cut surface are hatched (with diagonal lines), and portions that are not related to the cut surface but that appear in the cross-sectional view and require display are shown without hatching. The same applies to the following drawings.

[0023] The third sheet 30 may also be a single layer, or may be formed by stacking multiple sheets. When multiple sheets are stacked, the multiple sheets may be stacked and then formed into the following shape, or the multiple sheets may be processed individually and then stacked together to form the following shape.

[0024] In this embodiment, the third sheet 30 has a first surface 30a overlapping the inner surface 10a of the first sheet 10, a second surface 30b overlapping the inner surface 20a of the second sheet 20, and an end surface 30c spanning the first surface 30a and the second surface 30b to form a thickness. Therefore, the first surface 30a appears in Fig. 3 and the second surface 30b appears in Fig. 4.

[0025] The third sheet 30 also includes a main body 31 and an injection portion 32 . The main body 31 is a sheet-like portion that forms the hollow portion of the vapor chamber sheet and the sealed space in the vapor chamber 1, and in this embodiment is a rectangle with arcuate corners (so-called R) in plan view. However, the main body 31 may be rectangular as in this embodiment, or may have any other shape required for a vapor chamber. For example, it may be circular, elliptical, triangular, or other polygonal, or may have a bent portion such as an L-shape, T-shape, crank shape, or U-shape. It may also have a shape that combines at least two of these shapes.

[0026] Injection portion 32 is a portion where working fluid is injected into the formed hollow portion, and in this embodiment, it is in the form of a sheet that is rectangular in plan view and protrudes from one side of main body 31 that is rectangular in plan view. Injection portion 32 is provided with groove 32a on the second surface 30b side, which connects end surface 30c to main body 31.

[0027] The thickness of the third sheet 30 can be set to 0.03 mm or more and 0.8 mm or less. However, it is preferable that the thickness of the third sheet 30 is thicker than that of the first sheet 10 and the second sheet 20. This allows the cross section of the steam flow path 4, which will be described later, to be larger, allowing for smoother movement of the working fluid. The material of the third sheet 30 can be considered to be similar to that of the first sheet 10 and the second sheet 20.

[0028] A structure for circulating the working fluid is formed in the main body 31. Specifically, the main body 31 is configured to include an outer periphery joining portion 33, an outer periphery liquid flow path portion 34, an inner liquid flow path portion 38, a steam flow path groove 42, and a steam flow path connecting groove 44.

[0029] The vapor chamber 1 of this embodiment includes a vapor flow path 4 (see FIG. 15, etc.) which is a first flow path through which vapor of the working fluid passes, and a condensate flow path 3 (see FIG. 18, etc.) which is a second flow path through which condensed liquid obtained by condensing the working fluid passes. The vapor flow path groove 42 of the third sheet 30 forms the vapor flow path 4, and the liquid flow path grooves 35 and 36 (see FIG. 7, etc.) provided in the outer circumferential liquid flow path portion 34 and the liquid flow path grooves 39 and 40 (see FIGS. 13(a), 13(b), etc.) provided in the inner liquid flow path portion 38 form the condensate flow path 3.

[0030] <<Perimeter joint>> The outer peripheral joining portion 33 is a portion provided along the outer periphery of the main body 31, and includes an outer peripheral joining surface 33a provided on the first surface 30a of the main body 31 and an outer peripheral joining surface 33b provided on the second surface 30b. The outer peripheral joining surface 33a overlaps the outer periphery of the inner surface 10a of the first sheet 10, and the outer peripheral joining surface 33b overlaps the outer periphery of the inner surface 20a of the second sheet 20, and they are joined (diffusion bonding, brazing, etc.) to each other, thereby forming a hollow space based on the shape of the third sheet 30 between the first sheet 10 and the second sheet 20, and a working fluid is sealed in this hollow space to form an airtight space.

[0031] The width (size in a direction perpendicular to the direction of extension of the outer peripheral bonding portion 33) of the outer peripheral bonding portion 33 (the outer peripheral bonding surface 33a and the outer peripheral bonding surface 33b), indicated by W1 in FIGS. 3 to 7, can be set appropriately as needed. This width W1 is preferably 3.0 mm or less, and may be 2.5 mm or less, or may be 2.0 mm or less. If the width W1 is greater than 3.0 mm, the internal volume of the sealed space may be reduced, potentially making it difficult to ensure sufficient steam and condensate flow paths. On the other hand, the width W1 is preferably 0.1 mm or more, and may be 0.4 mm or more, or may be 0.8 mm or more. If the width W1 is less than 0.1 mm, there is a risk that the bonding area will be insufficient if misalignment occurs between the sheets during bonding. The range of the width W1 may be determined by combining any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Furthermore, the range of width W1 may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. Here, the width of the outer peripheral bonding surface 33a and the width of the outer peripheral bonding surface 33b are both indicated as W1, but the width of the outer peripheral bonding surface 33a and the width of the outer peripheral bonding surface 33b do not necessarily have to be the same and may be different widths.

[0032] <<Peripheral liquid flow path section>> The outer peripheral liquid flow path section 34 functions as a liquid flow path section and constitutes a part of the condensed liquid flow path 3, which is a second flow path through which the working fluid passes when condensed and liquefied. Figures 7(a) and 7(b) show an enlarged view of the part indicated by arrow C3 in Figure 5. Figure 8 shows an enlarged plan view (viewed from the z direction) of the outer peripheral liquid flow path section 34 as seen from the direction indicated by arrow C4 in Figure 7. That is, Figure 8 shows a part of the outer peripheral liquid flow path section 34 as seen from the first surface 30a. Here, Fig. 7(a) is C in Fig. 8 15 -C 15 7(b) is a cross-sectional view of the C in FIG. 16 -C 16 7(a) is a cross section in which the protrusion 35a is disposed on the introduction portion 37 side, and FIG. 7(b) is a cross section in which the communication opening 35b is disposed on the introduction portion 37 side.

[0033] As can be seen from these figures, the peripheral liquid flow path section 34 is formed along the inside of the peripheral joining section 33 of the main body 31, and is a section provided along the outer periphery of a section that becomes the sealed space 2. Furthermore, liquid flow path grooves 35 (on the first surface 30a side) and liquid flow path grooves 36 (on the second surface 30b side), which are multiple grooves extending along the outer periphery of the main body 31, are formed on each of the first surface 30a and the second surface 30b of the peripheral liquid flow path section 34, and the multiple liquid flow path grooves 35 and 36 are arranged at predetermined intervals in a direction different from the extending direction of the liquid flow path grooves 35 and 36. Therefore, as can be seen from Figures 5 to 7, in the cross section of the peripheral liquid flow path section 34, on the first surface 30a side, the liquid flow path grooves 35 that are recesses and the protrusions 35a that are between the liquid flow path grooves 35 are formed in a repeated uneven pattern. Furthermore, on the second surface 30b side, concave and convex portions 36a, which are concave portions, and convex portions 36a between the liquid flow path grooves 36 are repeatedly formed. That is, in this embodiment, liquid flow path grooves that become the condensate liquid flow paths 3 are provided on both sides (front and back) in the thickness direction (z direction).

[0034] In this way, by providing multiple liquid flow path grooves 35 and liquid flow path grooves 36 on each of the first surface 30a and the second surface 30b, the combined flow path cross-sectional area of ​​the condensate flow path 3 as a whole is ensured to be an appropriate size, allowing the condensate to flow at the required flow rate, and the depth and width of each liquid flow path groove 35 and liquid flow path groove 36 can be reduced, thereby reducing the flow path cross-sectional area of ​​the condensate flow path 3, which is the second flow path (see Figures 17(a), 17(b), etc.), and making use of strong capillary force. The depth and width of one side and the other side (front and back), i.e., the liquid flow path groove 35 and the liquid flow path groove 36, may be different from each other. This allows the flow rate and capillary force to be independently adjusted to suit the final product.

[0035] Here, since the liquid flow path grooves 35 and 36 are grooves, their cross-sectional shapes have bottoms and are open on the opposite side facing the bottoms. As will be described later, when the first sheet 10 or the second sheet 20 is placed on the third sheet 30, this opening is closed, forming the condensate flow path 3. In this embodiment, the liquid flow path grooves 35 and 36 have a semi-elliptical cross section. However, the cross-sectional shape is not limited to a semi-elliptical shape, and may be a circle, a quadrangle such as a rectangle, a square, or a trapezoid, or any other polygon, or a shape that combines two or more of these.

[0036] Furthermore, in this embodiment, in the outer peripheral liquid flow path section 34, adjacent liquid flow path grooves 35 are communicated with each other via communication openings 35b at a predetermined interval, as can be seen from Fig. 8. This promotes equalization of the amount of condensed liquid among the plurality of liquid flow path grooves 35, allowing the condensed liquid to flow efficiently and enabling smooth reflux of the working fluid. Note that Fig. 8 shows the first surface 30a side, so the liquid flow path grooves 35, the convex portions 35a, and the communication openings 35b will be described. However, the same can be said for the liquid flow path grooves 36 and the convex portions 36a provided on the second surface 30b side, which are provided with communication openings 36b (not shown) and can be considered to be the same as the liquid flow path grooves 35, the convex portions 35a, and the communication openings 35b.

[0037] In this embodiment, as shown in Fig. 8, the communicating openings 35b may be arranged at different positions in the extension direction of one liquid flow path groove 35, with the groove sandwiched between the communicating openings 35b. That is, the protrusions 35a and the communicating openings 35b are arranged alternately in a direction perpendicular to the extension direction of the liquid flow path groove. However, this is not limited to this, and for example, as shown in Fig. 9, the communicating openings 35b may be arranged so as to face each other at the same position in the extension direction of the liquid flow path groove 35, with the groove sandwiched between the communicating openings 35b.

[0038] Other configurations are also possible, for example, as shown in Figures 10 to 12. Figures 10 to 12 show, from the same perspective as Figure 8, one liquid flow path groove 35, two convex portions 35a sandwiching it, and one communication opening 35b provided in each convex portion 35a. In all of these, the shape of the convex portion 35a from that perspective (plan view) is different from the example in Figure 8. That is, in the protrusion 35a shown in Fig. 8, the width at the end where the communication opening 35b is formed is constant and the same as that at other portions. In contrast, in the protrusions 35a shaped as shown in Figs. 10 to 12, the width at the end where the communication opening 35b is formed is formed to be smaller than the maximum width of the protrusion 35a. More specifically, Fig. 10 shows an example in which the corners at the end are arc-shaped and rounded, thereby reducing the width of the end, Fig. 11 shows an example in which the end is semicircular, thereby reducing the width, and Fig. 12 shows an example in which the end is tapered to a sharp point.

[0039] As shown in Figures 10 to 12, the width of the end of the convex portion 35a where the communicating opening 35b is formed is formed to be smaller than the maximum width of the convex portion 35a, which makes it easier for the working fluid to move through the communicating opening 35b and facilitates the movement of the working fluid to the adjacent condensate flow path.

[0040] 5, an introduction section 37 is provided in the outer peripheral liquid flow path section 34. The introduction section 37 is a section formed at the boundary surface with the steam flow path groove 42, and is a section that protrudes toward the steam flow path groove 42. In this embodiment, the introduction section 37 has an apex 37a that protrudes most at the center in the thickness direction (z direction), and an introduction surface 37b that is concave in an arc shape toward the outer peripheral liquid flow path section 34 in a cross-sectional view is provided from the apex 37a toward the first surface 30a and the second surface 30b (z direction). The shape of the introduction portion 37 is not limited to this, and the position of the apex 37a may be anywhere in the z direction, and the introduction surface 37b may be a straight line in cross section or a curved line that is not an arc. Furthermore, the apex 37a may be a point in cross section, or may have a length.

[0041] With such an introduction section 37, the shape described above makes it easy for condensate to collect on the introduction surface 37b, which facilitates the movement of working fluid between the condensate flow path 3 and the steam flow path 4 through the introduction section 37, thereby further increasing the heat transport capacity.

[0042] The outer peripheral liquid flow path section 34 having the above-described configuration may further have the following configuration. Note that, for the sake of reference to the drawings, only the first surface 30a side will be described here, but the second surface 30b side (liquid flow path grooves 36, convex portions 36a, and communication openings 36b) can be considered similarly. However, this does not mean that the shape of the first surface 30a side and the shape of the second surface 30b side need to be the same; the shapes of the first surface 30a side and the second surface 30b side may be the same or different.

[0043] The width of the outer peripheral liquid flow path section 34, indicated by W2 in FIGS. 3 to 5 and 7(a) (the size in the direction in which the liquid flow path grooves 35 and 36 are arranged), can be appropriately set based on the overall size of the vapor chamber, etc. The width W2 is preferably 3.0 mm or less, and may be 1.5 mm or less, or may be 1.0 mm or less. If the width W2 exceeds 3.0 mm, there is a risk that there will not be enough space for the inner liquid flow paths and vapor flow paths. On the other hand, the width W2 is preferably 0.05 mm or more, and may be 0.1 mm or more, or may be 0.2 mm or more. If the width W2 is less than 0.05 mm, there is a risk that a sufficient amount of liquid will be circulated to the outside. The range of the width W2 may be determined by combining any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. The range of the width W2 may also be determined by combining any two of the multiple upper limit candidate values ​​or any two of the multiple lower limit candidate values. Here, the width of the outer peripheral liquid flow path portion 34 on the first surface 30a side and the width of the outer peripheral bonding surface 33b side are both indicated as W2, but the width of the outer peripheral bonding surface 33a and the width of the outer peripheral bonding surface 33b do not necessarily have to be the same and may be different widths.

[0044] Regarding the liquid flow path grooves 35, the groove width (the size in the direction in which the liquid flow path grooves 35 are arranged, the width at the opening surface of the groove) indicated by W3 in FIGS. 7(a) and 8 is preferably 1000 μm or less, and may be 500 μm or less, or may be 200 μm or less. On the other hand, the width W3 is preferably 20 μm or more, and may be 45 μm or more, or may be 60 μm or more. The range of the width W3 may be determined by combining any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Furthermore, the range of the width W3 may be determined by combining any two of the multiple upper limit candidate values, or any two of the multiple lower limit candidate values. Furthermore, the depth of the groove indicated by D1 in FIG. 7(a) is preferably 200 μm or less, and may be 150 μm or less, or 100 μm or less. On the other hand, the depth D1 is preferably 5 μm or more, and may be 10 μm or more, or may be 20 μm or more. The range of the depth D1 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. Furthermore, the range of the depth D1 may be determined by combining any two of the plurality of upper limit candidate values, or by combining any two of the plurality of lower limit candidate values. By configuring as above, the capillary force of the condensate flow path necessary for reflux can be exerted more strongly.

[0045] To maximize the capillary force of the condensate flow path, the aspect ratio (length-to-length ratio) of the flow path cross section, which is calculated by dividing the groove width W3 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. Among these, from the viewpoint of manufacturing, it is preferable that W3 is larger than D1, and from this viewpoint, it is preferable that the aspect ratio is larger than 1.3.

[0046] Furthermore, the pitch between adjacent liquid flow path grooves 35 among the plurality of liquid flow path grooves 35 indicated by P1 in FIG. 7(a) is preferably 1100 μm or less, and may be 550 μm or less, or 220 μm or less. On the other hand, the pitch P1 is preferably 30 μm or more, and may be 55 μm or more, or may be 70 μm or more. The range of this pitch P1 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. Furthermore, the range of the pitch P1 may be determined by combining any two of the plurality of upper limit candidate values, or by combining any two of the plurality of lower limit candidate values. This makes it possible to increase the density of the condensate flow path while suppressing the condensate flow path from being crushed due to deformation during joining or assembly.

[0047] The size of the communication opening 35b along the direction in which the liquid flow path groove 35 extends, indicated by L1 in FIG. 8, is preferably 1100 μm or less, and may be 550 μm or less, or 220 μm or less. On the other hand, the size L1 is preferably 30 μm or more, and may be 55 μm or more, or may be 70 μm or more. The range of the size L1 may be determined by combining any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. Furthermore, the range of the size L1 may be determined by combining any two of the plurality of upper limit candidate values, or any two of the plurality of lower limit candidate values.

[0048] Furthermore, the pitch between adjacent communication openings 35b in the direction in which the liquid flow path groove 35 extends, indicated by L2 in FIG. 8, is preferably 2700 μm or less, and may be 1800 μm or less, or may be 900 μm or less. On the other hand, this pitch L2 is preferably 60 μm or more, and may be 110 μm or more, or may be 140 μm or more. The range of this pitch L2 may be determined by combining any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. Furthermore, the range of the pitch L2 may be determined by combining any two of the plurality of upper limit candidate values, or any two of the plurality of lower limit candidate values.

[0049] Regarding the introduction portion 37, the protrusion amount (distance from the end of the convex portion 35a to the apex 37a) indicated by W4 in FIG. 7(a) is preferably 1000 μm or less, and may be 500 μm or less, or may be 300 μm or less. On the other hand, the protrusion amount W4 is preferably 20 μm or more, and may be 45 μm or more, or may be 60 μm or more. The range of the protrusion amount W4 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. Furthermore, the range of the protrusion amount W4 may be determined by combining any two of the plurality of upper limit candidate values, or by combining any two of the plurality of lower limit candidate values.

[0050] <<Inner liquid flow path section>> Returning to Figures 1 to 5, the inner liquid flow path section 38 will now be described. The inner liquid flow path section 38 also functions as a liquid flow path section, and is a part that constitutes part of the condensate flow path 3, which is the second flow path through which the working fluid passes when condensed and liquefied, and the introduction section 41. Figures 13(a) and 13(b) show an enlarged view of the part indicated by arrow C5 in Figure 5. Figures 13(a) and 13(b) also show the cross-sectional shape of the inner liquid flow path section 38. Figure 14 shows an enlarged plan view of the inner liquid flow path section 38 as seen from the direction indicated by arrow C6 in Figure 13. Here, Fig. 13(a) is C in Fig. 14 17 -C 17 13(b) is a cross-sectional view taken along the arrow C in FIG. 14. 18 -C18 13(a) is a cross section where the protrusion 39a is arranged on the introduction portion 41 side, and FIG. 13(b) is a cross section where the communication opening 39b is arranged on the introduction portion 41 side.

[0051] As can be seen from these figures, the inner liquid flow path section 38 is a portion of the main body 31 formed inside the annular ring of the outer peripheral liquid flow path section 34. In this embodiment, the inner liquid flow path section 38 extends in a direction (x direction) parallel to the long side of the rectangle in a plan view of the main body 31 (when viewed from the z direction), and multiple (three in this embodiment) inner liquid flow path sections 38 are arranged at predetermined intervals in a direction (y direction) parallel to the short side.

[0052] A plurality of liquid flow path grooves 39 (on the first surface 30a side) and liquid flow path grooves 40 (on the second surface 30b side) are formed on each of the first surface 30a and second surface 30b of the inner liquid flow path section 38, extending along the direction in which the inner liquid flow path section 38 extends, and the plurality of liquid flow path grooves 39 and 40 are arranged at predetermined intervals in a direction different from the direction in which the liquid flow path grooves 39 and 40 extend. 13 and other figures, in the cross section of the inner liquid flow path section 38, liquid flow path grooves 39, which are recesses, and convex portions 39a between the liquid flow path grooves 39 are formed in a repeated pattern on the first surface 30a side. Furthermore, liquid flow path grooves 40, which are recesses, and convex portions 40a between the liquid flow path grooves 40 are formed in a repeated pattern on the second surface 30b side. That is, in this embodiment, liquid flow path grooves that become the condensate liquid flow paths 3 are provided on both one side and the other side (front and back) in the thickness direction (z direction).

[0053] In this way, by providing multiple liquid flow path grooves 39 and liquid flow path grooves 40 on each of the first surface 30a and the second surface 30b, the combined flow path cross-sectional area of ​​the condensate flow path 3 as a whole is ensured to be an appropriate size, allowing the condensate to flow at the required flow rate, and by reducing the depth and width of each liquid flow path groove 39 and liquid flow path groove 40, the flow path cross-sectional area of ​​the condensate flow path 3 (see Figure 18, etc.), which is the second flow path, can be reduced, making it possible to utilize strong capillary force.

[0054] Here, since the liquid flow path grooves 39 and 40 are grooves, their cross-sectional shapes have bottoms and are open on the opposite side facing the bottoms. As will be described later, when the first sheet 10 and the second sheet 20 are placed on the third sheet 30, these openings are closed to form the condensate flow paths 3. In this embodiment, the liquid flow path grooves 39 and 40 have a semi-elliptical cross section. However, the cross-sectional shape is not limited to a semi-elliptical shape, and may be a circle, a quadrangle such as a rectangle, a square, or a trapezoid, or any other polygon, or a shape that combines two or more of these.

[0055] Furthermore, in this embodiment, in the inner liquid flow path section 38, as can be seen from Fig. 14, adjacent liquid flow path grooves 39 are communicated with each other via communication openings 39b at a predetermined interval. This promotes equalization of the amount of condensed liquid among the plurality of liquid flow path grooves 39, allowing the condensed liquid to flow efficiently and enabling smooth reflux of the working fluid. Note that Fig. 14 shows the first surface 30a side, so the liquid flow path grooves 39, the convex portions 39a, and the communication openings 39b will be described. However, the same can be said for the liquid flow path grooves 40 and the convex portions 40a provided on the second surface 30b side, which are provided with communication openings 40b (not shown) and can be considered to be the same as the liquid flow path grooves 39, the convex portions 39a, and the communication openings 39b. Furthermore, similarly to the above-described communicating opening 35b, the communicating opening 39b may be arranged so that the communicating opening 39b is at the same position along a direction perpendicular to the extending direction of the liquid flow path grooves 39 and 40, following the example shown in Fig. 9. Furthermore, the communicating opening 39b and the convex portion 39a may have shapes following the examples of Figs. 10 to 12.

[0056] In this embodiment, an introduction section 41 is provided in the inner liquid flow path section 38. The introduction section 41 is a section formed at the boundary surface with the steam flow path groove 42, and is a section that protrudes toward the steam flow path groove 42. In this embodiment, the introduction section 41 has an apex 41a that protrudes most at the center in the thickness direction (z direction), and an introduction surface 41b that is concave in an arc shape toward the inner liquid flow path section 38 in a cross-sectional view is provided from the apex 41a toward the first surface 30a and the second surface 30b (z direction). The shape of the introduction portion 41 is not limited to this, and the position of the apex 41a may be anywhere in the z direction, and the introduction surface 41b may be a straight line in cross section or a curved line that is not an arc. Also, the apex 41a may be a point in cross section or may have a length.

[0057] With such an introduction section 41, the shape described above makes it easy for condensate to collect on the introduction surface 41b, which facilitates the movement of working fluid between the condensate flow path 3 and the steam flow path 4 through the introduction section 41, thereby further increasing the heat transport capacity.

[0058] The inner liquid flow path section 38 having the above-described configuration preferably further has the following configuration. The width of the inner liquid flow path section 38 (the largest value in the direction in which the inner liquid flow path section 38 and the vapor flow path grooves 42 are arranged), indicated by W5 in FIGS. 3, 4, 5, and 13(a), is preferably 3000 μm or less, and may be 2000 μm or less, or may be 1500 μm or less. On the other hand, the width W5 is preferably 100 μm or more, and may be 200 μm or more, or may be 400 μm or more. The range of the width W5 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. Furthermore, the range of the width W5 may be determined by combining any two of the plurality of upper limit candidate values, or any two of the plurality of lower limit candidate values.

[0059] Furthermore, the pitch of the multiple inner liquid flow path sections 38, indicated by P2 in Figures 3 and 5, is preferably 5000 µm or less, but may be 3500 µm or less, or may be 3000 µm or less. On the other hand, this pitch P2 is preferably 200 µm or more, but may be 400 µm or more, or may be 800 µm or more. The range of this pitch P2 may be determined by combining any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Furthermore, the range of the pitch P2 may be determined by combining any two of the multiple upper limit candidate values, or by combining any two of the multiple lower limit candidate values. This reduces the flow resistance of the steam flow path, and allows for a good balance between the movement of steam and the return of condensed liquid.

[0060] The inner liquid flow path section 38 having the above configuration may further have the following configuration. Note that, for the sake of reference to the drawings, only the first surface 30a side will be described here, but the second surface 30b side (liquid flow path grooves 40, convex portions 40a, and communication openings 40b) can be considered similarly. However, this does not mean that the shape of the first surface 30a side and the shape of the second surface 30b side need to be the same; the shapes of the first surface 30a side and the second surface 30b side may be the same or different.

[0061] Regarding the liquid flow path grooves 39, the groove width (the size in the direction in which the liquid flow path grooves 39 are arranged, and the width at the groove opening surface) indicated by W6 in FIGS. 13(a) and 14 is preferably 1000 μm or less, and may be 500 μm or less, or may be 200 μm or less. On the other hand, this width W6 is preferably 20 μm or more, and may be 45 μm or more, or may be 60 μm or more. The range of this width W6 may be determined by combining any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Furthermore, the range of width W6 may be determined by combining any two of the multiple upper limit candidate values, or any two of the multiple lower limit candidate values.

[0062] The depth of the liquid flow path groove 39, indicated by D2 in FIG. 13(a), is preferably 200 μm or less, but may be 150 μm or less, or may be 100 μm or less. On the other hand, the depth D2 is preferably 5 μm or more, but may be 10 μm or more, or may be 20 μm or more. The range of the depth D2 may be determined by combining any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. The range of the depth D2 may also be determined by combining any two of the plurality of upper limit candidate values, or any two of the plurality of lower limit candidate values. This allows the capillary force of the condensate flow path, which is necessary for reflux, to be exerted strongly.

[0063] From the viewpoint of exerting a stronger capillary force in the flow channel, the aspect ratio (length-to-length ratio) of the flow channel cross section, which is expressed by dividing the groove width W6 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 may be 0.75 or less, or 0.5 or less. Among these, from the viewpoint of manufacturing, it is preferable that the groove width W6 is larger than the depth D2, and from this viewpoint, it is preferable that the aspect ratio is larger than 1.3.

[0064] Furthermore, the pitch between adjacent liquid flow path grooves 39 in the plurality of liquid flow path grooves 39, indicated by P3 in FIG. 13(a), is preferably 1100 μm or less, and may be 550 μm or less, or 220 μm or less. On the other hand, this pitch P3 is preferably 30 μm or more, and may be 55 μm or more, or may be 70 μm or more. The range of this pitch P3 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. Furthermore, the range of the pitch P3 may be determined by combining any two of the plurality of upper limit candidate values, or by combining any two of the plurality of lower limit candidate values. This makes it possible to increase the density of the condensate flow path while suppressing deformation and collapse of the flow path during joining or assembly.

[0065] Furthermore, the size of the communication opening 39b along the direction in which the liquid flow path groove 39 extends, indicated by L3 in FIG. 14, is preferably 1100 μm or less, and may be 550 μm or less, or 220 μm or less. On the other hand, this size L3 is preferably 30 μm or more, and may be 55 μm or more, or may be 70 μm or more. The range of this size L3 may be determined by combining any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. Furthermore, the range of size L3 may be determined by combining any two of the multiple upper limit candidate values, or any two of the multiple lower limit candidate values.

[0066] Furthermore, the pitch between adjacent communication openings 39b in the direction in which the liquid flow path groove 39 extends, indicated by L4 in FIG. 14, is preferably 2700 μm or less, but may be 1800 μm or less, or may be 900 μm or less. On the other hand, this pitch L4 is preferably 60 μm or more, but may be 110 μm or more, or may be 140 μm or more. The range of this pitch L4 may be determined by combining any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. Furthermore, the range of this pitch L4 may be determined by combining any two of the plurality of upper limit candidate values, or any two of the plurality of lower limit candidate values.

[0067] In the above-described embodiment, the liquid flow path grooves 35 and 36, and the liquid flow path grooves 39 and 40 are arranged parallel to each other at equal intervals, but this is not limited to this, and the pitch between the grooves may vary as long as they can produce capillary action, and the grooves do not have to be parallel to each other.

[0068] Regarding the introduction portion 41, the protrusion amount (distance from the end of the convex portion 39a to the apex 41a) indicated by W7 in FIG. 13(a) is preferably 1000 μm or less, and may be 500 μm or less, or may be 300 μm or less. On the other hand, the protrusion amount W7 is preferably 20 μm or more, and may be 45 μm or more, or may be 60 μm or more. The range of the protrusion amount W7 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. Furthermore, the range of the protrusion amount W7 may be determined by combining any two of the plurality of upper limit candidate values, or by combining any two of the plurality of lower limit candidate values.

[0069] <<Steam flow groove>> Next, the steam flow path groove 42 will be described. The steam flow path groove 42 is a portion through which vaporized steam generated when the working fluid evaporates, and constitutes part of the steam flow path 4 (see FIG. 15, etc.), which is the first flow path. The shape of the steam flow path groove 42 as viewed from above is shown in FIGS. 3 and 4, and the cross-sectional shape of the steam flow path groove 42 is shown in FIG. 5.

[0070] As can be seen from these figures, in this embodiment, the steam flow path grooves 42 are configured as grooves (slits) formed inside the annular ring of the outer peripheral liquid flow path section 34 of the main body 31. More specifically, the steam flow path grooves 42 in this embodiment are formed between adjacent inner liquid flow path sections 38 and between the outer peripheral liquid flow path section 34 and the inner liquid flow path section 38, and are rectangular in plan view of the main body 31, extending in a direction parallel to the long sides (x direction). A plurality of (four in this embodiment) steam flow path grooves 42 are arranged in a direction parallel to the short sides (y direction). The steam flow path grooves 42 in this embodiment are configured to communicate between the first surface 30a and the second surface 30b of the third sheet 30; that is, they are slit-shaped grooves that penetrate the third sheet 30 in the thickness direction, open to the first surface 30a and the second surface 30b, and extend along the sheet surfaces (first surface 30a, second surface 30b) of the third sheet 30. are. Therefore, as can be seen from FIG. 5, the third sheet 30 has a shape in which the outer peripheral liquid flow path portions 34, inner liquid flow path portions 38, and steam flow path grooves 42 are alternately repeated in the y direction.

[0071] The steam flow channel groove 42 having such a configuration can further have the following configuration. The width of the vapor flow channel groove 42, indicated by W8 in FIGS. 3, 4, and 5 (the dimension in the direction in which the inner liquid flow channel section 38 and the vapor flow channel groove 40 are arranged, and the width at the opening surface of the vapor flow channel groove) is greater than at least the width W3 of the liquid flow channel grooves 35 and 37 and the width W6 of the liquid flow channel grooves 39 and 40, and is preferably 2500 μm or less, may be 2000 μm or less, or may be 1500 μm or less. On the other hand, the width W8 is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. The range of the width W8 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. The range of the width W8 may also be determined by combining any two of the plurality of upper limit candidate values ​​or any two of the plurality of lower limit candidate values. The pitch of the vapor flow channel grooves 42 is usually determined by the pitch of the inner liquid flow channel portions 38 . By making the flow path cross-sectional area of ​​the steam flow path groove larger than the flow path cross-sectional area of ​​the liquid flow path groove, it is possible to smoothly return the steam, which has a larger volume than the condensed liquid due to the nature of the working fluid.

[0072] In this embodiment, the cross-sectional shape of the steam flow channel groove 42 is determined based on the introduction portion 37 and introduction portion 41, but if introduction portion 41 is not provided, the cross-sectional shape may be a quadrilateral such as a rectangle, a square, or a trapezoid, a triangle, or a combination of two or more of these. The steam flow channel can reduce the flow resistance of the steam to allow the working fluid to return smoothly, so the shape of the flow channel cross section can also be determined from this perspective.

[0073] In this embodiment, an example has been described in which one steam flow path groove 42 is formed between adjacent inner liquid flow path sections 38, but this is not limited to this, and the embodiment may also be such that two or more steam flow path grooves are arranged side by side between adjacent inner liquid flow path sections.

[0074] <<Steam flow path communication groove>> The steam flow path communication grooves 44 are grooves that communicate with the multiple steam flow path grooves 42. This allows the steam in the multiple steam flow path grooves 42 to be equalized, the steam to be transported over a wider area, and many condensate flow paths 3 to be used efficiently, thereby enabling smoother reflux of the working fluid.

[0075] As can be seen from Figures 3, 4, and 6, the steam flow path communication groove 44 in this embodiment is formed between both ends of the inner liquid flow path section 38 and the steam flow path groove 42 in the direction in which they extend, and the outer circumferential liquid flow path section 34.

[0076] The steam flow path communication groove 44 is formed to communicate with adjacent steam flow path grooves 42. In this embodiment, as can be seen from Fig. 6, the steam flow path communication groove 44 has a groove 44a on the first surface 30a side and a groove 44b on the second surface 30b side, and is provided with a connecting portion 44c between the grooves 44a and 44b. This connecting portion 44c connects the inner liquid flow path portion 38 and the outer peripheral liquid flow path portion 33 and holds the inner liquid flow path portion 38. 3 and 4, in this embodiment, a hole 44d is provided in the connecting portion 44c of the steam flow path communicating groove 44 at a location where the end of groove 32a provided in the injection portion 32 of the third sheet 30 is located, thereby connecting groove 44a to groove 44b. This allows for smoother injection of the working fluid without impeding the injection of the working fluid from groove 32a.

[0077] The steam flow path communication groove 44 is only required to connect the plurality of steam flow path grooves 42, and its shape is not particularly limited, but it may have the following configuration, for example. The width of the steam flow path communication groove 44 (the size in the direction perpendicular to the communication direction, the width at the opening surface of the groove), indicated by W9 in FIGS. 3, 4, and 6, is preferably 2500 μm or less, and may be 2000 μm or less, or 1500 μm or less. On the other hand, the width W9 is preferably 100 μm or more, and may be 200 μm or more, or may be 400 μm or more. The range of the width W9 may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. Furthermore, the range of the width W9 may be determined by combining any two of the plurality of upper limit candidate values, or any two of the plurality of lower limit candidate values.

[0078] In this embodiment, the cross-sectional shape of grooves 44a and 44b of the steam flow path connecting groove 44 is semi-elliptical, but is not limited to this and may be rectangular, square, trapezoid or other quadrilateral, triangular, semicircular, with a semi-circular bottom, with a semi-elliptical bottom, or a combination of any two or more of these. The steam flow passage communication grooves can reduce the flow resistance of the steam, thereby allowing the working fluid to return smoothly, and the shape of the flow passage cross section can also be determined from this perspective.

[0079] <Vapor chamber structure> Next, we will explain the structure of the vapor chamber 1 when the first sheet 10, the second sheet, and the third sheet 30 are combined. This explanation will help to further understand the shape of the vapor chamber 1, as well as the arrangement, size, shape, etc. of each component that the first sheet 10, the second sheet, and the third sheet 30 should have.

[0080] Fig. 15 shows a cross-sectional view of the vapor chamber 1 cut in the thickness direction along the y direction indicated by C7-C7 in Fig. 1. Fig. 16 shows a cross-sectional view of the vapor chamber 1 cut in the thickness direction along the x direction indicated by C8-C8 in Fig. 1. 17(a) shows a cross section corresponding to FIG. 7(a) at the part indicated by C9 in FIG. 15, FIG. 17(b) shows a cross section corresponding to FIG. 7(b), and FIG. 18(a) shows a cross section corresponding to C9 in FIG. 10The cross section corresponding to FIG. 13(a) is shown at the portion indicated by , and the cross section corresponding to FIG. 13(b) is shown in FIG. 18(b). In the cross sections shown in Figures 15, 16, 17(a), and 18(a), the steam flow path 4 and the steam flow path 3 are separated by the convex portions 35a and 39a, but as shown in and explained with reference to Figures 8 and 14, the convex portions 35a and 39a are provided with the communication openings 35b and 39b, respectively. Therefore, in the cross sections shown in Figures 17(b) and 18(b) where the communication openings 35b and 39b contact the steam flow path 4, the steam flow path 4 and the steam flow path 3 are in communication with each other through the communication openings 35b and 39b.

[0081] 1, 2, and 15 to 18, the inner surface 10a of the first sheet 10 is superimposed on the first surface 30a of the third sheet 30, and the inner surface 20a of the second sheet 20 is superimposed on the second surface 30b of the third sheet 30, and they are arranged and joined to form the vapor chamber 1. At this time, the main body 31 of the third sheet 30 and the main body 11 of the first sheet 10 overlap, the main body 31 of the third sheet 30 and the main body 21 of the second sheet 20 overlap, the injection portion 32 of the third sheet 30 overlaps with the injection portion 12 of the first sheet 10, and the injection portion 32 of the third sheet 30 overlaps with the injection portion 22 of the second sheet 20.

[0082] The laminate of the first sheet 10, the second sheet 20, and the third sheet 30 allows the components of the main body 11, the main body 21, and the main body 31 to be arranged as shown in Figures 15, 16, 17(a), 17(b), 18(a), and 18(b). Specifically, this is as follows.

[0083] The third sheet 30 is arranged so that the outer peripheral joining surface 33a provided on the first surface 30a side and the outer peripheral surface of the inner surface 10a of the first sheet 10 overlap, and the third sheet 30 is arranged so that the outer peripheral joining surface 33b provided on the second surface 30b side and the outer peripheral surface of the inner surface 20a of the second sheet 20 overlap, and they are joined by joining means such as diffusion bonding or brazing. As a result, a hollow space based on the shape of the third sheet 30 is formed between the first sheet 10 and the second sheet 20, and a working fluid is sealed in this hollow space to form the sealed space 2.

[0084] The third sheet 30 is arranged so that the inner surface 10a of the first sheet 10 overlaps the first surface 30a of the outer peripheral liquid flow path portion 34 of the third sheet 30. As a result, the opening of the liquid flow path groove 35 is blocked by the first sheet 10, forming part of the hollow portion. This forms the condensate flow path 3, which is a second flow path through which condensed liquid, which is the working fluid sealed in the hollow portion and condensed into a liquefied state, flows. Similarly, the second sheet 20 is arranged so that the inner surface 20a of the second sheet 20 overlaps the second surface 30b of the outer peripheral liquid flow path portion 34 of the third sheet 30. As a result, the opening of the liquid flow path groove 36 is blocked by the second sheet 20, forming part of the hollow portion. This forms the condensate flow path 3, which is a second flow path through which condensed liquid, which is the working fluid sealed in the hollow portion and condensed into a liquefied state, flows.

[0085] The first sheet 10 is also arranged so that the inner surface 10a of the first sheet 10 overlaps the first surface 30a of the inner liquid flow path portion 38 of the third sheet 30. As a result, the opening of the liquid flow path groove 39 is blocked by the first sheet 10, forming part of the hollow portion. This forms the condensate flow path 3, which is a second flow path through which condensed liquid, which is the working fluid sealed in the hollow portion and condensed into a liquefied state, flows. Similarly, the second sheet 20 is arranged so that the inner surface 20a of the second sheet 20 overlaps the second surface 30b of the outer peripheral liquid flow path portion 38 of the third sheet 30. As a result, the opening of the liquid flow path groove 40 is blocked by the second sheet 20, forming part of the hollow portion. This forms the condensate flow path 3, which is a second flow path through which condensed liquid, which is the working fluid sealed in the hollow portion and condensed into a liquefied state, flows.

[0086] In this way, by forming a thin flow path surrounded by walls on all four sides in cross section, the condensate is moved by strong capillary force, enabling smooth circulation. In other words, when considering a flow path through which the condensate is expected to flow, the condensate flow path 3 can obtain a stronger capillary force than a so-called groove flow path in which one side of the flow path is continuously open. Furthermore, since the condensate flow path 3 is formed separately from the steam flow path 4, which is the first flow path, the circulation of the working fluid can be made smooth.

[0087] Furthermore, in this embodiment, a condensate flow path 3 consisting of liquid flow path grooves 35 and 39 and a condensate flow path 3 consisting of liquid flow path grooves 36 and 40 are provided, and a condensate flow path 3 is provided on each of one side and the other side of the thickness direction (z direction) of the vapor chamber 1. This allows the cross-sectional area of ​​one condensate flow path 3 to be small (thinner) while the total cross-sectional area of ​​the condensate flow paths 3 to be large, thereby maintaining a high capillary force and smoothing the flow of condensate. Furthermore, the working fluid in the vapor chamber 1 can be given the opportunity to move not only in the in-plane direction (xy direction) but also in the thickness direction (z direction), which is expected to result in more uniform heat transfer and heat transport.

[0088] The shape of the condensate flow path 3 can be considered based on the shape and dimensions explained for the third sheet 30 above.

[0089] 15, the opening of the steam flow path groove 42 is closed by the first sheet 10 and the second sheet 20 to form a part of a hollow portion, which serves as a flow path for the enclosed working fluid and becomes the steam flow path 4, which is the first flow path through which steam flows. Here, it is preferable that the surfaces of the first sheet 10 and the second sheet 20 that form part of the steam flow path 4 on the steam flow path 4 side are flat. In this embodiment, the surfaces of the first sheet 10 and the second sheet 20 are not processed and have flat plate surfaces, so that the inner wall of the steam flow path 4 is smooth and resistance to steam movement can be reduced.

[0090] The cross-sectional area of ​​the condensate flow path 3, which is the second flow path, is 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 (in this embodiment, a flow path surrounded by one steam flow path groove 42, the first sheet 10, and the second sheet 20) is defined as A g The average cross-sectional area of ​​the plurality of condensate flow paths 3 (the plurality of condensate flow paths 3 surrounded by one inner liquid flow path portion 38, the first sheet 10, and the second sheet 20 in this embodiment) arranged between two adjacent steam flow paths 4 is defined as A l When the condensate flow path 3 and the steam flow path 4 are l A g The relationship is 0.5 times or less, and preferably 0.25 times or less, so that the working fluid can easily pass selectively through the first flow path and the second flow path depending on its phase (gas phase, liquid phase). This relationship needs to be satisfied in at least a portion of the entire vapor chamber, and it is more preferable that this relationship be satisfied in the entire vapor chamber.

[0091] The shape of the steam flow path 4 can be considered based on the shape and dimensions explained for the third sheet 30 above. In this embodiment, since the introduction part 37 and the introduction part 41 are provided, one steam flow path 4 is configured to be in contact with two introduction parts.

[0092] As can be seen from Figure 16, the opening of groove 44a of the steam flow path communication groove 44 of the third sheet 30 is blocked by the first sheet 10, and the opening of groove 44b is blocked by the second sheet 20, thereby forming a hollow portion that communicates with multiple steam flow paths 4 and serves as a flow path for the working fluid.

[0093] As shown in Figures 1 and 2, injection section 12, injection section 22, and injection section 32 overlap on the first surface 30a side of injection section 32, and injection section 22 overlaps on the second surface 30 side of injection section 32, and the opening of injection groove 32a on the second surface 30b side of third sheet 30 is blocked by injection section 22 of second sheet 20, forming an injection flow path 5 that connects the outside with the hollow section (condensate flow path 3 and steam flow path 4). However, after the working fluid is injected into the hollow portion from the injection flow path 5, the injection flow path 5 is closed to form a sealed space 2, so that in the final form of the vapor chamber 1, the hollow portion is not connected to the outside. In this embodiment, the injection part 12, the injection part 22, and the injection part 32 are provided at one end of a pair of ends in the longitudinal direction of the vapor chamber 1, but this is not limited thereto and they may be arranged at any other end, or multiple injection parts may be arranged. When multiple injection parts are arranged, they may be arranged at each of a pair of ends in the longitudinal direction of the vapor chamber 1, or at one end of the other pair of ends.

[0094] A working fluid is sealed in the sealed space 2 of the vapor chamber 1. The type of working fluid is not particularly limited, but working fluids used in ordinary vapor chambers, such as pure water, ethanol, methanol, acetone, and mixtures thereof, can be used.

[0095] [Manufacturing of vapor chambers] The vapor chamber as described above can be fabricated, for example, as follows. Liquid flow path grooves 35, 36, 39, 40, vapor flow path grooves 42, and grooves 44a and 44b are formed by half-etching in a sheet having the outer peripheral shape of third sheet 30. Half-etching means etching partway through the thickness without penetrating the sheet. However, the vapor flow path groove 42 is half-etched from both the first surface 30a side and the second surface 30b side so as to penetrate through in the thickness direction. By performing etching in this manner, the shapes of the introduction portion 37 and the introduction portion 41 can be formed.

[0096] Next, the first sheet 10 is placed on the first surface 30a of the third sheet 30, and the second sheet 20 is placed on the second surface 30b of the third sheet 30, and they are temporarily joined together. The method of temporary joining is not particularly limited, but examples include resistance welding, ultrasonic welding, and adhesion using an adhesive. After temporary joining, the first sheet 10, the second sheet 20, and the third sheet 30 are permanently joined by diffusion bonding to form a vapor chamber sheet. Note that brazing may be used instead of diffusion bonding. Here, "permanently joined" is not limited to a strict meaning, but means that the sheets are joined to a degree that allows the sealed space 2 to maintain its airtightness when the vapor chamber 1 is in operation.

[0097] After joining, a vacuum is drawn from the formed injection channel 5 to reduce the pressure in the hollow portion. Thereafter, the working fluid is injected from the injection channel 5 into the reduced pressure hollow portion, and the working fluid is placed in the hollow portion. Then, the overlapping injection portions 12, 22, and 32 are welded using fusion or crimped to close the injection channel 5 and form an airtight space. This allows the working fluid to be stably held inside the airtight space 2.

[0098] In the vapor chamber of this embodiment, the internal liquid flow path portion 38 functions as a support, so that the collapse of the sealed space can be prevented during joining and decompression.

[0099] Although the above describes the manufacturing of a vapor chamber by etching, the manufacturing method is not limited to this, and the vapor chamber can also be manufactured by press processing, cutting processing, laser processing, and processing using a 3D printer. For example, when manufacturing a vapor chamber using a 3D printer, it is not necessary to create the vapor chamber by joining multiple sheets, and it is possible to create a vapor chamber with no joints.

[0100] [Structure of electronic devices and function of vapor chambers] Next, the operation of vapor chamber 1 will be explained. Figure 19 shows a schematic diagram of vapor chamber 1 disposed inside portable terminal 80, which is one form of electronic device. Here, vapor chamber 1 is shown by a dotted line because it is disposed inside housing 81 of portable terminal 80. Portable terminal 80 is configured with housing 81 that houses various electronic components and display unit 82 that is exposed so that images can be seen to the outside through an opening in housing 81. One of these electronic components is electronic component 53, which should be cooled by vapor chamber 1, and is disposed inside housing 51.

[0101] Vapor chamber 1 is installed within the housing of a portable terminal or the like, and is attached to electronic component 83, such as a CPU, which is the object to be cooled. The electronic component is attached directly to the outer surface of vapor chamber 1, or via a highly thermally conductive adhesive, sheet, tape, or the like. The location of electronic component 83 within the vapor chamber is not particularly limited and is appropriately determined depending on the location of other components in the portable terminal or the like. In this embodiment, as shown by the dotted line in FIG. 1 , electronic component 53 is located on the surface of second sheet 20 opposite the side on which third sheet 30 is located, in the center of main body 21 in the x- and y-directions. Therefore, electronic component 83 is shown by the dotted line in FIG. 1 because it is in a blind spot and cannot be seen. 20 is a diagram illustrating the flow of the working fluid. For ease of explanation, this diagram shows the first surface 30a of the third sheet 30 inside the vapor chamber 1.

[0102] When the electronic components 83 generate heat, the heat is transferred by thermal conduction within the second sheet 20, and is absorbed by the condensate present in the sealed space 2 at a position close to the electronic components 83. The condensate absorbs the heat and evaporates, thereby cooling the electronic components 83.

[0103] The evaporated working fluid becomes vapor and flows through the vapor flow path 4 as shown by the solid arrow in Figure 20. This flow occurs in a direction away from the electronic component 83, so the vapor moves in a direction away from the electronic component 83. The vapor in the vapor flow path 4 moves away from the electronic component 83, which is the heat source, and moves to the outer periphery of the vapor chamber 1, which is at a relatively low temperature, and is cooled as it moves while heat is absorbed by the first sheet 10, the second sheet 20, and the third sheet 30, in that order. The first sheet 10, the second sheet 20, and the third sheet 30 absorb the heat from the vapor and transfer the heat to the housing 81 of the electronic device 80, etc., which are in contact with the vapor chamber, and the heat is finally released into the outside air.

[0104] The working fluid that has lost heat while moving through the steam flow path 4 condenses and becomes liquid. This condensed liquid adheres to the wall surface of the steam flow path 4. On the other hand, since steam is continuously flowing through the steam flow path 4, the condensed liquid adheres to the wall surface of the steam flow path 4. 11 As shown in FIG. 8 and FIG. 14 , the condensate moves to the condensate flow passage 3 as if being pushed by the steam. The condensate flow passage 3 of this embodiment is provided with the communication openings 35b, 36b, 39b, and 40b, as shown in FIG. 8 and FIG. 14 , and therefore the condensate passes through these communication openings and is distributed to the plurality of condensate flow passages 3.

[0105] In this embodiment, the condensate flow path 3 is provided on both sides of the thickness of the vapor chamber 1, which increases the opportunities for movement from the steam flow path 4 to the condensate flow path 3, allowing for smoother movement of the condensate. In this case, if the inlet portion 37 and the inlet portion 41 are provided, there will be areas surrounded by the inlet surface 37b, the inlet surface 41b, the first sheet 10, and the second sheet 20, and the condensate will tend to accumulate there due to the action of capillary force. This will allow the condensate to be introduced into the condensate flow path 3 more smoothly.

[0106] The condensate that has entered the condensate flow path 3 moves toward the electronic component 83, which is the heat source, as indicated by the dotted straight arrow in Figure 20, due to the capillary force of the condensate flow path and the pressure from the steam. Then, the heat from the electronic component 83, which is the heat source, causes the vaporization again, and the above process is repeated.

[0107] As described above, the vapor chamber 1 allows the condensate to flow back smoothly in the condensate flow path due to a strong capillary force, thereby increasing the amount of heat transport. Furthermore, in this embodiment, the condensate flow paths 3 are provided on both sides of the vapor chamber 1 in the thickness direction (z direction). This allows the cross-sectional area of ​​one condensate flow path 3 to be small (thinner) while the total cross-sectional area of ​​the condensate flow paths 3 to be large, thereby maintaining a high capillary force and smoothing the flow of condensate. Furthermore, the working fluid in the vapor chamber 1 can be given the opportunity to move not only in the in-plane direction (xy direction) but also in the thickness direction (z direction), which is expected to result in more uniform heat transfer and heat transport.

[0108] [Number of seats] The vapor chamber 1 described so far has been an example made up of three sheets: the first sheet 10, the second sheet 20, and the third sheet 30. By using three sheets in this way, the overlapping of the sheets is not as complicated as when more sheets are used, making manufacturing easier and allowing the bonding of each sheet to be stronger. Among these, if the surfaces of the first sheet 10 and the second sheet 20 are flat and unprocessed, as in this embodiment, there is no need to worry about alignment when overlapping the sheets to form condensate flow paths and vapor flow paths, making manufacturing easier.

[0109] However, regardless of the number of sheets, it is sufficient that the condensate flow paths are provided on one side and the other side of the vapor chamber in the thickness direction, and the number of sheets may be four or five. In this way, by constructing the vapor chamber with three or more sheets, it is easier to form the introduction surface 41b as shown in Figure 18 compared to when it is constructed with two sheets, making it easier for the working fluid to condense here and allowing the working fluid to move more smoothly. Furthermore, for example, as shown in Figure 21, when the third sheet is divided in the thickness direction to form a vapor chamber using a total of four sheets, a groove can also be formed in the center of the thickness direction of the inner liquid flow path portion 38 to provide a condensate flow path.

[0110] 1.2.Form 1b 22 to 25 are diagrams illustrating a vapor chamber 51 according to embodiment 1b. 22 is an exploded perspective view of the vapor chamber 51, and corresponds to FIG. 2. FIG. 23 is a view showing the sealed space 2 of the vapor chamber 51, and is a view showing the first surface 30a side of the third sheet 52. FIG. 24 is a view showing the sealed space 2 of the vapor chamber 51, and corresponds to FIG. 23. 12 -C 12 FIG. 25 shows a cross-sectional view of the vapor chamber 101 cut at the position indicated by C in FIG. 13 18. This is an enlarged view of the area around the part (inner liquid flow path section 138) indicated by the dotted line and corresponds to FIG.

[0111] The vapor chamber 51 differs from the above-described vapor chamber 1 in that a third sheet 52 is used instead of the third sheet 30, and the third sheet 52 has a thickness-direction communicating hole 54a formed in an inner liquid flow path portion 54 of a main body 53 thereof. The description of the other members and parts is applicable to the vapor chamber 1, so the same reference numerals are used in the drawings and their description will be omitted. Therefore, the following description will focus on the thickness-direction communicating hole 54a formed in the inner liquid flow path portion 54.

[0112] The thickness-wise communicating holes 54a are provided in the inner liquid flow path portion 54 of the third sheet 52, and are holes that communicate from the first surface 30a to the second surface 30b. The thickness-wise communicating holes 54a connect the liquid flow path grooves 39 and 40, and connect the condensate liquid flow paths 3 on the first surface 30a side to the condensate liquid flow paths 3 on the second surface 30b side. This results in arrow C in Figure 25. 14 As shown in Fig. 1, the condensate flow paths 3 arranged separately in the thickness direction communicate with each other without passing through the steam flow paths 4, which further equalizes the distribution of the condensate, allowing the working fluid to flow more smoothly.

[0113] The thickness-direction communicating holes 54a are only required to communicate the condensate liquid flow paths 3 arranged on one side of the thickness direction of one inner liquid flow path section 54 with those arranged on the other side, and the specific form for this purpose is not particularly limited. For example, this can be explained as follows.

[0114] The cross-sectional shape of the thickness-wise communicating hole 54a shown in Figures 22 and 23 is not particularly limited, and can be a circle, an ellipse, a triangle, a rectangle, other polygons, or a geometric shape formed by combining these.

[0115] 24 and 25, the shape of the thickness-direction communicating holes 54a in the direction in which they extend (z direction) is not particularly limited, and the cross-sectional shape may be constant or may vary at each position in the z direction. For example, the cross-sectional area of ​​the portion in contact with the condensate flow path 3 may be larger than that of other portions.

[0116] The number of condensate flow paths 3 connected by one thickness-direction communicating hole 54a is not particularly limited. As in this embodiment, two condensate flow paths 3 on the first surface 30a and two condensate flow paths 3 on the second surface 30b may be configured to communicate with each other, or one or three or more condensate flow paths 3 may be configured to communicate with each other on one surface in the thickness direction.

[0117] The vapor chamber 1 can exhibit its effect if it is provided with just one thickness-wise communicating hole 54a, but it is preferable to provide a plurality of thickness-wise communicating holes 54a for a more pronounced effect.

[0118] There are no particular limitations on the form in which multiple thickness direction communicating holes 54a are provided, and one may be provided in one inner liquid flow path section 54, or multiple thickness direction communicating holes 54a may be provided in one inner liquid flow path section 54. When multiple thickness direction communicating holes 54a are arranged in one inner liquid flow path section 54, they may be arranged in a straight line, or, as shown in Figure 23, adjacent thickness direction communicating holes 54a may be shifted in position in the direction perpendicular to the arranging direction (y direction).

[0119] In this embodiment, the thickness-wise communicating holes 54a are provided only in the inner liquid flow path section 54, but instead, thickness-wise communicating holes may be provided only in the outer peripheral liquid flow path section 34, or thickness-wise communicating holes may be provided in both the inner liquid flow path section 54 and the outer peripheral liquid flow path section 34.

[0120] 2. Form 2 2.1.Form 2a [Components] FIG. 26 shows a perspective view of the exterior of a vapor chamber 101 according to embodiment 2a, and FIG. 27 shows an exploded perspective view of the vapor chamber 101. As can be seen from FIGS. 26 and 27, the vapor chamber 101 of this embodiment has a first sheet 10, a second sheet 20, and a third sheet 130 (sometimes referred to as an "intermediate sheet 130"). As will be described later, these sheets are stacked and joined (by diffusion bonding, brazing, or the like) to form a vapor chamber sheet in which a hollow portion based on the shape of the third sheet 130 is formed between the first sheet 10 and the second sheet 20. A working fluid is then sealed in the hollow portion to form a sealed space 102 (see, for example, FIG. 19 ), which constitutes the vapor chamber 101.

[0121] The first sheet 10 and second sheet 20 provided in this embodiment can be considered to be the same as the first sheet 10 and second sheet 20 described in embodiment 1, so they will be given the same symbols and their explanation will be omitted.

[0122] <Third sheet> In this embodiment, the third sheet 130 is a sheet that is sandwiched and stacked between the inner surface 10a of the first sheet 10 and the inner surface 20a of the second sheet 20, and is provided with a structure for the sealed space 2 through which the working fluid moves. 28 and 29 show plan views (viewed from the z direction) of the third sheet 130. Fig. 28 is a view of the surface that is superimposed on the first sheet 10, and Fig. 29 is a view of the surface that is superimposed on the second sheet 20. Also, Figure 30 shows C in Figure 28. 101 -C 101 31 shows a cross section along the line indicated by C in Fig. 28. 102 -C 102The cross-sectional views along the lines indicated by are shown.

[0123] The third sheet 130 may also be a single layer, or may be formed by stacking multiple sheets. When multiple sheets are stacked, the multiple sheets may be stacked and then formed into the following shape, or the multiple sheets may be processed individually and then stacked together to form the following shape.

[0124] In this embodiment, the third sheet 130 has a first surface 130a that overlaps the inner surface 10a of the first sheet 10, a second surface 130b that overlaps the inner surface 20a of the second sheet 20, and an end surface 130c that spans the first surface 130a and the second surface 130b to form a thickness. Therefore, the first surface 130a appears in Fig. 28 and the second surface 130b appears in Fig. 29.

[0125] The third sheet 130 includes a main body 131 and an injection section 32. The injection section 32 of this embodiment can be considered to be similar to the injection section 32 shown in embodiment 1, and therefore the same reference numerals are used and the description thereof will be omitted. The main body 31 is a sheet-like portion that forms the hollow portion of the vapor chamber sheet and the sealed space in the vapor chamber 1, and in this embodiment is a rectangle with arcuate (so-called R) corners in a plan view. However, the main body 31 may be rectangular as in this embodiment, or may have any other shape required for a vapor chamber. For example, it may be circular, elliptical, triangular, or other polygonal, or may have a bent portion such as an L-shape, a T-shape, a crank-shape, or a U-shape. It may also have a shape that combines at least two of these shapes.

[0126] The thickness and material of the third sheet 130 can be considered to be similar to those of the first sheet 10. However, the thickness and material of the third sheet 130 do not need to be the same as those of the first sheet 10, and may be different.

[0127] A structure for circulating the working fluid is formed in the main body 131. Specifically, the main body 131 is configured to include an outer periphery joining portion 33, an outer periphery liquid flow path portion 134, an inner liquid flow path portion 138, a steam flow path groove 142, and a steam flow path connecting groove 144.

[0128] The vapor chamber 101 of this embodiment includes a vapor flow path 4 (see FIG. 38, etc.) which is a first flow path through which vapor of the working fluid passes, and a condensate flow path 3 (see FIG. 42, etc.) which is a second flow path through which condensate obtained by condensing the working fluid passes. The vapor flow path groove 142 of the third sheet 130 forms the vapor flow path 4, and the liquid flow path groove 35 provided in the outer peripheral liquid flow path portion 134 and the liquid flow path groove 39 provided in the inner liquid flow path portion 138 form the condensate flow path 3.

[0129] <<Perimeter joint>> The outer peripheral joint 33 can be considered to be the same as the outer peripheral joint 33 described in the first embodiment above, and therefore the same reference numerals are used here and the description thereof will be omitted.

[0130] <<Peripheral liquid flow path section>> The outer circumferential liquid flow path portion 134 functions as a liquid flow path portion, and constitutes a part of the condensed liquid flow path 3, which is a second flow path through which the working fluid passes when condensed and liquefied, and also includes a portion that constitutes the heat insulating portion 6. 103 The part indicated by arrow C in Figure 32 is shown enlarged. 105 33 shows an enlarged view of the outer peripheral liquid flow path section 134 as seen from the direction indicated by the arrow Z. That is, Figure 33 shows a part of the outer peripheral liquid flow path section 134 as seen from the second surface 130b.

[0131] As can be seen from these figures, the outer circumferential liquid flow path section 134 is formed along the inside of the outer circumferential joining section 33 of the main body 131 and is provided along the outer periphery of the section that becomes the sealed space 2.

[0132] Liquid flow path grooves 35, which are multiple grooves extending parallel to the outer circumferential direction of the main body 131, are formed on the first surface 130a of the outer circumferential liquid flow path portion 134, and the multiple liquid flow path grooves 35 are arranged at predetermined intervals in a direction different from the direction in which they extend. The liquid flow path grooves 35 can be considered to be similar to the liquid flow path grooves 35 described in the first embodiment above, and therefore the same reference numerals are used here and the description thereof will be omitted.

[0133] As can be seen from FIGS. 29 to 33, in this embodiment, the outer peripheral liquid flow path section 134 is provided with a groove 136 for a heat insulating section on the second surface 30b side. The insulating groove 136 is a groove that extends in the direction in which the outer peripheral liquid flow path portion 134 extends, and is not connected to the steam flow path groove 42 or the liquid flow path groove 35, and is configured so that the working fluid does not flow into the insulating groove 136.

[0134] Here, since the heat insulating groove 136 is a groove, its cross section has a bottom and an opening on the opposite side (second surface 130b) facing the bottom. As will be described later, when the second sheet 20 is placed on the third sheet 30, this opening is closed to form the heat insulating portion 6. In this embodiment, the cross section of the heat insulating groove 136 is semi-elliptical. However, the cross section is not limited to a semi-elliptical shape, and may be a circle, a quadrangle such as a rectangle, a square, or a trapezoid, or any other polygon, or a shape that combines two or more of these.

[0135] Also, in Figure 34, C shown in Figure 33 106 -C 106 34 is a cross-sectional view of the outer peripheral liquid flow path section 134 at a portion where the pillars 136a are provided. On the other hand, the cross section shown in FIG. 32 is a cross-sectional view of the outer peripheral liquid flow path section 134 at a portion of the heat insulating section groove 136 where the pillars 136a are not arranged. As can be seen from these figures, multiple pillars 136a are arranged at intervals inside the groove for heat insulation 136, standing upright from the bottom. These pillars 136a prevent the groove for heat insulation 136 from collapsing when the third sheet 130 is joined to the second sheet 20, and also increase the strength of the vapor chamber 101 itself.

[0136] The planar shape of the pillar (the shape from the viewpoint of Figure 33) is not particularly limited, and in addition to being rectangular as in this embodiment, polygons such as triangles and pentagons, circles, ellipses, or any other shape can be applied.

[0137] Furthermore, the pitch and number of the columns to be arranged are not particularly limited and can be set as appropriate. Therefore, the number of columns may be one or fewer, and each column may be configured long so as to extend along the groove for the heat insulating portion.

[0138] 30, the peripheral liquid flow path section 134 is provided with an introduction section 37. The introduction section 37 can be considered to be the same as the introduction section 37 described in the first embodiment, and therefore the same reference numerals are used and the description thereof will be omitted.

[0139] The peripheral liquid flow path section 134 having the above-described configuration may further have the following configuration.

[0140] 28 to 30 and 32. 102 The width of the outer peripheral liquid flow path section 134 (the size in the direction in which the liquid flow path grooves 35 are arranged) shown by can be appropriately set based on the size of the entire vapor chamber, etc. 102 The width W is preferably 3.0 mm or less, may be 1.5 mm or less, or may be 1.0 mm or less. 102 If the width W exceeds 3.0 mm, there is a risk that there will not be enough space for the internal liquid flow path and vapor flow path. 102 The width W is preferably 0.05 mm or more, may be 0.1 mm or more, or may be 0.2 mm or more. 102 If the width W is less than 0.05 mm, there is a risk that the amount of liquid circulating around the outside will not be sufficient. 102 The range of width W may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 102 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. Here, the width of the outer peripheral liquid flow path section 134 on the first surface 130a side and the width on the second surface 130b side are both W 102 However, the width of the outer peripheral joining surface 33a and the width of the outer peripheral joining surface 33b do not necessarily have to be the same, and may be different widths.

[0141] Regarding the groove 136 for the heat insulating part, W is shown in FIG. 104 The groove width indicated by is preferably 1500 μm or less, may be 1000 μm or less, or may be 700 μm or less. 104 The width W is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. 104 The range of width W may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 104 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. Also, in Figure 32, D 102 The depth of the groove indicated by is preferably 200 μm or less, may be 150 μm or less, or may be 100 μm or less. 102 The depth D is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. 102 The range of depth D may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 102 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values.

[0142] <<Inner liquid flow path section>> 26 to 30, the inner liquid flow path section 138 will be described. The inner liquid flow path section 138 is also a part of the condensate flow path 3, which is the second flow path through which the working fluid passes when condensed and liquefied, a part constituting the heat insulating section 6, and a part constituting the introduction section 41. 10735 also shows the cross-sectional shapes of the inner liquid flow path section 38, the heat insulating groove 140, and the introduction section 41. Also, FIG. 36 shows the area indicated by the arrow C in FIG. 109 1 shows an enlarged plan view of the inner liquid flow path section 138 as seen from the direction indicated by the arrow.

[0143] As can be seen from these figures, the inner liquid flow path section 138 is a portion of the main body 131 formed inside the annular ring of the outer peripheral liquid flow path section 134. In this embodiment, the inner liquid flow path section 138 extends in a direction (x direction) parallel to the long side of the rectangle in a plan view of the main body 131 (when viewed from the z direction), and multiple (three in this embodiment) inner liquid flow path sections 138 are arranged at predetermined intervals in a direction (y direction) parallel to the short side.

[0144] Liquid flow path grooves 39, which are multiple grooves extending along the direction in which the inner liquid flow path section 138 extends, are formed on the first surface 130a of the inner liquid flow path section 138, and the multiple liquid flow path grooves 39 are arranged at predetermined intervals in a direction different from the direction in which the liquid flow path section 138 extends. Here, the liquid flow path grooves 39 can be considered to be the same as the liquid flow path grooves 39 described in the first embodiment, and therefore the same reference numerals are used and the description thereof will be omitted.

[0145] As can be seen from Figures 29, 30, 35 and 36, the inner liquid flow path section 138 is provided with a groove 140 for a heat insulating section in the second surface 130b. The groove 140 for the insulation section is a groove that extends along the direction in which the inner liquid flow path section 138 extends, and is not connected to the steam flow path groove 42 or the liquid flow path groove 39, and is configured so that the working fluid does not flow into the groove 140 for the insulation section.

[0146] Here, since the heat insulating groove 140 is a groove, its cross section has a bottom and an opening on the opposite side (second surface 130b) facing the bottom. As will be described later, this opening is closed by overlapping the second sheet 20 with the third sheet 30, thereby forming the heat insulating portion 6. In this embodiment, the cross section of the heat insulating groove 140 is semi-elliptical. However, the cross section is not limited to a semi-elliptical shape, and may be a circle, a quadrangle such as a rectangle, a square, or a trapezoid, or any other polygon, or a shape that combines two or more of these.

[0147] Also, in Figure 37, C shown in Figure 36 110 -C 110 37 shows a cross-sectional view along the line 37. That is, Fig. 37 is a cross-sectional view of the inner liquid flow path section 138 at a portion where the pillars 140a are provided. On the other hand, the cross-sectional view shown in Fig. 35 is a cross-sectional view of the inner liquid flow path section 138 at a portion of the heat insulation groove 140 where the pillars 140a are not arranged. As can be seen from these figures, multiple pillars 140a standing upright from the bottom are arranged at intervals within the groove for heat insulation 140. These pillars 140a prevent the groove for heat insulation 140 from collapsing when the third sheet 130 is joined to the second sheet 20, and also increase the strength of the vapor chamber 101 itself.

[0148] The planar shape of the pillar (shape from the viewpoint of Figure 36) is not particularly limited, and in addition to being rectangular as in this embodiment, polygons such as triangles and pentagons, circles, ellipses, or any other shape can be applied.

[0149] Furthermore, the pitch and number of the columns to be arranged are not particularly limited and can be set as appropriate. Therefore, the number of columns may be limited to one or fewer, and each column may be configured long enough to extend along the heat insulating groove.

[0150] In this embodiment, an introduction section 41 is provided in the inner liquid flow path section 138. This introduction section 41 can be considered to be the same as the introduction section 41 described in embodiment 1, and therefore the same reference numerals are used and the description thereof will be omitted.

[0151] The inner liquid flow path section 138 having the above-described configuration preferably further has the following configuration. 28 to 30 and 35. 106The width of the inner liquid flow path section 138 (the largest value in the direction in which the inner liquid flow path section 138 and the vapor flow path grooves 42 are arranged) is preferably 3000 μm or less, and may be 2000 μm or less, or may be 1500 μm or less. 106 The width W is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. 106 The range of width W may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 106 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values.

[0152] Also, in Figure 30, P 102 The pitch of the plurality of inner liquid flow path sections 138 indicated by is preferably 5000 μm or less, may be 3500 μm or less, or may be 3000 μm or less. 102 The pitch P is preferably 200 μm or more, may be 400 μm or more, or may be 800 μm or more. 102 The range of pitch P may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 102 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. This reduces the flow resistance of the steam flow path, and allows for a good balance between the movement of steam and the return of condensed liquid.

[0153] The inner liquid flow path section 38 having the above-described configuration may further have the following configuration.

[0154] Regarding the groove 140 for the heat insulating part, W is shown in FIG. 108 The groove width indicated by is preferably 1500 μm or less, may be 1000 μm or less, or may be 700 μm or less. 108The width W is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. 108 The range of width W may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 108 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. Also, in Figure 35, D 104 The depth of the groove indicated by is preferably 200 μm or less, may be 150 μm or less, or may be 100 μm or less. 104 The depth D is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. 104 The range of depth D may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 104 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values.

[0155] <<Steam flow groove>> Next, the steam flow path groove 142 will be described. The steam flow path groove 142 is a portion through which vaporized steam generated when the working fluid evaporates, and constitutes part of the steam flow path 4 (see FIG. 19, etc.), which is the first flow path. The shape of the steam flow path groove 142 in plan view is shown in FIG. 28 and FIG. 29, and the cross-sectional shape of the steam flow path groove 142 is shown in FIG. 30.

[0156] As can be seen from these figures, in this embodiment, the steam flow path grooves 142 are grooves (slits) formed inside the annular ring of the outer peripheral liquid flow path section 134 of the main body 131. More specifically, the steam flow path grooves 142 in this embodiment are formed between adjacent inner liquid flow path sections 138 and between the outer peripheral liquid flow path section 134 and the inner liquid flow path section 138, and are rectangular in plan view of the main body 131, extending in a direction parallel to the long sides (x direction). A plurality of (four in this embodiment) steam flow path grooves 142 are arranged in a direction parallel to the short sides (y direction). The steam flow path grooves 142 in this embodiment are configured to communicate between the first surface 130a and the second surface 130b of the third sheet 130; that is, they are slit-shaped grooves that open to the first surface 130a and the second surface 130b. Therefore, as can be seen from FIG. 30, the third sheet 130 has a shape in which the outer circumferential liquid flow path portions 134, inner liquid flow path portions 138, and steam flow path grooves 142 are alternately repeated in the y direction.

[0157] The steam flow channel groove 142 having such a configuration can be considered to have the same configuration as the steam flow channel groove 42 described in the first embodiment.

[0158] <<Steam flow path communication groove>> The steam flow path communication groove 44 is a groove that connects multiple steam flow path grooves 142, and can be considered to be similar to the steam flow path communication groove 44 described in the above-mentioned embodiment 1, so the same symbol is used and the description is omitted.

[0159] [Vapor chamber structure] Next, we will explain the structure of the vapor chamber 101 when the first sheet 10, the second sheet, and the third sheet 130 are combined together. This explanation will help to further understand the shape of the vapor chamber 101, as well as the arrangement, size, shape, etc. of each component that the first sheet 10, the second sheet, and the third sheet 130 should have.

[0160] Figure 38 shows the C in Figure 26. 111 -C 111 39 shows a cross-sectional view of the vapor chamber 101 cut in the thickness direction along the y direction indicated by C in FIG.112 -C 112 1 shows a cross-sectional view of the vapor chamber 101 cut in the thickness direction along the x direction indicated by . Figure 40 shows C in Figure 38 113 41 shows the portion of the outer peripheral liquid flow path section 134 where the pillars 136a are provided, and FIG. 42 shows the portion of the outer peripheral liquid flow path section 134 where the pillars 136a are provided. 114 43 shows an enlarged view of the portion of the inner liquid flow path section 138 where the pillars 140a are provided. 38 to 43, the steam flow path 4 and the condensate flow path 3 are separated by the convex portions 35a and 39a, but the convex portions 35a and 39a are provided with the communication openings 35b and 39b, respectively. Therefore, the steam flow path 4 and the condensate flow path 3 are in communication with each other through the communication openings 35b and 39b.

[0161] 26, 27, and 38 to 42, the inner surface 10a of the first sheet 10 is superimposed on the first surface 130a of the third sheet 130, and the inner surface 20a of the second sheet 20 is superimposed on the second surface 130b of the third sheet 130, and they are joined together to form the vapor chamber 101. At this time, the main body 131 of the third sheet 130 and the main body 11 of the first sheet 10 overlap, the main body 131 of the third sheet 130 and the main body 21 of the second sheet 20 overlap, the injection portion 32 of the third sheet 130 and the injection portion 12 of the first sheet 10 overlap, and the injection portion 32 of the third sheet 130 and the injection portion 22 of the second sheet 20 overlap.

[0162] The laminate of the first sheet 10, the second sheet 20, and the third sheet 130 allows the components of the main body 11, the main body 21, and the main body 131 to be arranged as shown in Figures 38 to 42. Specifically, the arrangement is as follows.

[0163] The third sheet 130 is arranged so that an outer peripheral joining surface 33a provided on the first surface 130a side thereof overlaps with the outer peripheral surface of the inner surface 10a of the first sheet 10, and the third sheet 30 is arranged so that an outer peripheral joining surface 33b provided on the second surface 30b side thereof overlaps with the outer peripheral surface of the inner surface 20a of the second sheet 20, and they are joined by a joining method such as diffusion bonding or brazing. As a result, a hollow space based on the shape of the third sheet 130 is formed between the first sheet 10 and the second sheet 20, and a working fluid is sealed in this hollow space to form the sealed space 102.

[0164] The third sheet 130 is arranged so that the inner surface 10a of the first sheet 10 overlaps the first surface 130a of the outer peripheral liquid flow path portion 134 of the third sheet 130. As a result, the opening of the liquid flow path groove 35 is blocked by the first sheet 10, forming part of the hollow portion. This forms a condensate flow path 3, which is a second flow path through which condensed liquid, which is the working fluid sealed in the hollow portion and condensed into a liquefied state, flows.

[0165] The second sheet 20 is arranged so that the inner surface 20a of the second sheet 20 overlaps the second surface 30b of the outer peripheral liquid flow path portion 134 of the third sheet 130. As a result, the opening of the heat insulating portion groove 136 is blocked by the second sheet 20, forming the heat insulating portion 6. The heat insulating portion 6 is configured not to communicate with the condensate flow path 3 and the steam flow path 4, and has a lower thermal conductivity than the material adjacent to the heat insulating portion 6. There are no particular limitations on the specific configuration, and the heat insulating portion 6 may be evacuated, filled with air or other gas, or filled with a material having low thermal conductivity.

[0166] The third sheet 130 is also arranged so that the inner surface 10a of the first sheet 10 overlaps the first surface 130a of the inner liquid flow path portion 138 of the third sheet 130. As a result, the opening of the liquid flow path groove 39 is blocked by the first sheet 10 and becomes part of the hollow portion. This forms a condensate flow path 3, which is a second flow path through which condensed liquid, which is the working fluid sealed in the hollow portion and condensed into a liquefied state, flows.

[0167] The second sheet 20 is arranged so that the inner surface 20a of the second sheet 20 overlaps the second surface 130b of the inner liquid flow path portion 138 of the third sheet 130. As a result, the opening of the heat insulating portion groove 140 is blocked by the second sheet 20, forming the heat insulating portion 6. The heat insulating portion 6 is configured not to communicate with the condensate flow path 3 and the steam flow path 4, and this portion has a lower thermal conductivity than the material adjacent to the heat insulating portion 6. There are no particular limitations on the specific configuration, and the heat insulating portion 6 may be evacuated, filled with air or other gas, or filled with a material having low thermal conductivity.

[0168] In this way, by forming a thin flow path surrounded by walls on all four sides in cross section in the condensate flow path 3, the condensate is moved by strong capillary force, enabling smooth circulation. In other words, when considering a flow path through which the condensate is expected to flow, the condensate flow path 3 can obtain a stronger capillary force than a so-called groove flow path in which one side of the flow path is continuously open. Furthermore, since the condensate flow path 3 is formed separately from the steam flow path 4, which is the first flow path, the circulation of the working fluid can be made smooth.

[0169] Meanwhile, a heat insulating section with reduced thermal conductivity is provided on the opposite side of the condensate flow path 3 in the thickness direction (z direction) of the vapor chamber 101. This slows down the transfer of heat to the working fluid, reducing local temperature increases and decreases, thereby improving uniformity. More specifically, it is possible to suppress problems such as dryout due to sudden heating and obstruction of the flow of the working fluid due to clogging of condensate due to unnecessarily rapid condensation, thereby improving heat transport capacity.

[0170] The shapes of the condensate flow path 3 and the heat insulating portion 6 can be considered based on the shape and dimensions explained for the third sheet 130 above.

[0171] Other parts will now be described. As can be seen from Fig. 38, the opening of the steam flow path groove 142 is blocked by the first sheet 10 and the second sheet 20 to form a part of a hollow portion, which forms a flow path for the working fluid and becomes the steam flow path 4, which is the first flow path through which steam flows. The relationship between the flow path cross-sectional area of ​​the condensate flow path 3 and the flow path cross-sectional area of ​​the steam flow path 4 can be considered to be the same as the relationship between the flow path cross-sectional area of ​​the condensate flow path 3 and the flow path cross-sectional area of ​​the steam flow path 4 described in embodiment 1.

[0172] The shape of the steam flow path 4 can be considered based on the shape and dimensions described above for the third sheet 130 . In this embodiment, since the introduction part 37 and the introduction part 41 are provided, the vapor flow path 4 is configured to be in contact with the two introduction parts.

[0173] As can be seen from Figure 39, the opening of groove 44a of the steam flow path communication groove 44 of the third sheet 130 is blocked by the first sheet 10, and the opening of groove 44b is blocked by the second sheet 20, thereby forming a hollow portion that connects multiple steam flow paths 4 and serves as a flow path for the working fluid.

[0174] A working fluid is sealed in the sealed space 102 of the vapor chamber 101. The type of working fluid is not particularly limited, but working fluids used in ordinary vapor chambers, such as pure water, ethanol, methanol, acetone, and mixtures thereof, can be used.

[0175] [Manufacturing of vapor chambers] The vapor chamber as described above can be fabricated, for example, as follows. Liquid flow path groove 35, heat insulating groove 136, liquid flow path groove 39, heat insulating groove 140, steam flow path groove 142, and grooves 44a and 44b are formed by half etching in a sheet having the outer peripheral shape of third sheet 130. However, steam flow path groove 142 is half-etched from both the first surface 130a side and the second surface 130b side so as to penetrate through in the thickness direction. By etching in this manner, the shapes of introduction portion 37 and introduction portion 41 can also be formed.

[0176] Next, the first sheet 10 is placed on the first surface 130a side of the third sheet 130, and the second sheet 20 is placed on the second surface 130b side of the third sheet 130, and they are temporarily joined together. The method of temporary joining is not particularly limited, but examples include resistance welding, ultrasonic welding, and adhesion with an adhesive. After temporary joining, the first sheet 10, the second sheet 20, and the third sheet 130 are permanently joined by diffusion bonding to form a vapor chamber sheet. Note that brazing may be used instead of diffusion bonding. Here, "permanently joined" is not limited to a strict meaning, but means that the sheets are joined to a degree that allows the sealing of the sealed space 102 to be maintained when the vapor chamber 101 is in operation. By performing this joining in a vacuum, the heat insulating section 6 can be evacuated, and by performing it in air or other gas, the heat insulating section 6 can be filled with the corresponding gas. If the heat insulating section groove 136 is provided with pillars 136a and the heat insulating section groove 140 is provided with pillars 140a, it is possible to prevent the heat insulating section 6 from collapsing or expanding during joining, as well as when the hollow section is decompressed and when the working fluid is injected, as described below. Furthermore, if a solid material is to be placed in the heat insulating section 6, the material can be placed in the heat insulating section groove before joining.

[0177] After joining, a vacuum is drawn from the formed injection channel 5 to reduce the pressure in the hollow portion. Thereafter, the working fluid is injected from the injection channel 5 into the reduced pressure hollow portion, and the working fluid is placed in the hollow portion. Then, the overlapping injection portions 12, 22, and 32 are welded using fusion or crimped to close the injection channel 5 and form an airtight space. This allows the working fluid to be stably held inside the airtight space 102.

[0178] In the vapor chamber of this embodiment, the internal liquid flow path portion 138 functions as a support, so that the collapse of the sealed space can be prevented during joining and decompression.

[0179] [Vapor chamber function] Next, we will explain the operation of vapor chamber 101. The arrangement of vapor chamber 101 in the electronic device is as explained in embodiment 1 (FIGS. 1 and 19). In addition, the movement of the working fluid and the diffusion of heat in condensate flow path 3 and vapor flow path 4 can also be considered in the same way as explained in embodiment 1.

[0180] In this embodiment, the heat insulating section 6 is provided on the opposite side of the condensate flow path 3 in the thickness direction (z direction) of the vapor chamber 101, so that heat is transferred to the working fluid more slowly, reducing local temperature increases and decreases, thereby improving uniformity. In other words, it is possible to suppress problems such as dryout due to rapid heating and obstruction of the flow of the working fluid due to clogging of the condensate caused by unnecessarily rapid condensation, thereby improving heat transport capacity. Therefore, the heat insulating portion does not necessarily have to be disposed over the entire vapor chamber, but may be disposed only in areas where local heat transfer is expected, such as areas where a heat source (electronic component) is disposed, or conversely, the end of the vapor chamber that is remote from the heat source.

[0181] Furthermore, if the introduction section 37 and the introduction section 41 are provided, there will be areas surrounded by the introduction surface 37b, the introduction surface 41b, the first sheet 10, and the second sheet 20, and the condensate will be more likely to accumulate there due to the action of capillary force. This will allow the condensate to be introduced into the condensate flow path 3 more smoothly.

[0182] 2.2. Other Forms Figure 44 shows an example in which the grooves 140 for the heat insulating portion are provided in a part of the second surface 130b of the third sheet 130. This figure corresponds to Figure 29. As a result, the heat insulating portion 6 is also limited to the area where the grooves 140 for the heat insulating portion are provided. This allows the heat insulating portion to be provided in accordance with the thermal design, for example, by providing the heat insulating portion 6 in an area close to the object to be cooled and an area where condensation should be suppressed, and not providing the heat insulating portion 6 in an area where rapid condensation is desired.

[0183] 45 to 47 show examples in which a heat insulating portion 6 is also provided in the steam flow path 4. All of these figures correspond to FIG. Fig. 45 shows an example in which a heat insulating section 6 is provided in each of the condensate flow path 3 and the steam flow path 4. Fig. 46 shows an example in which a heat insulating section 6 is provided in communication with the condensate flow path 3 and the steam flow path 4. Fig. 47 shows an example in which a heat insulating section 6 is provided only in the steam flow path 4.

[0184] 3.Form 3 While the introduction section 37 and the introduction section 39 were described in the first and second embodiments, the introduction section will be described in detail in the third embodiment. Therefore, the configuration other than the introduction section can be considered similar to that of the first and second embodiments, and therefore description thereof will be omitted. Furthermore, in the first embodiment, the second surface 30b of the third sheet 30 is provided with liquid flow path grooves 40, and in the second embodiment, the second surface 130b of the third sheet 130 is provided with heat insulating grooves 140. However, since these elements do not necessarily have to be provided on the second surface of the third sheet, an example in which these elements are not provided on the second surface of the third sheet will be described here. However, this does not preclude the liquid flow path grooves 40 and the heat insulating grooves 140 from being provided on the second surface of the third sheet. In the following description, the elements other than the introductory part will use the same symbols as those used in the first embodiment.

[0185] 3.1.Form 3a Figures 48(a) and 48(b) are diagrams illustrating the inner liquid flow path section 238, and correspond to Figures 13(a) and 13(b). Note that although the introduction section 241 will be described here using the inner liquid flow path section 238, the same can be applied to the introduction section provided in the outer liquid flow path section.

[0186] In this embodiment, an introduction section 241 is provided in the inner liquid flow path section 238. The introduction section 241 is a section formed on the boundary surface with the steam flow path groove 42, and is a section that protrudes toward the steam flow path groove 42. Therefore, in this embodiment, an introduction section 241 is arranged on both sides of the inner liquid flow path section 238 in the width direction (y direction). In this embodiment, the introduction portion 241 is formed such that the introduction portion 241 is located at a position T from the first surface 30a (the top of the convex portion 39a of the liquid flow path groove) in the thickness direction (z direction). 203The inlet surface 241b has an apex 241a that protrudes most at this position, and is provided with an arc-shaped inlet surface 241b that is concave toward the inner liquid flow path section 238 in cross section from the apex 241a toward the liquid flow path groove 39. However, the inlet surface 241b does not have to be arc-shaped, and may be a curved shape other than an arc that is concave toward the inner liquid flow path section 238 in cross section. Other examples of the introduction part will be shown later, but all of the introduction parts have a surface (introduction surface) that protrudes toward the steam flow path groove 42 (steam flow path) and has a surface that approaches the liquid flow path groove (condensate flow path) from its most protruding apex.

[0187] Such an introduction section 241 allows condensate to easily collect on the introduction surface 241b, facilitating smooth movement of the working fluid between the condensate flow path 3 and the vapor flow path 4 through the introduction section 241, thereby improving heat transport capacity.

[0188] The surface of the inlet surface 241b is not particularly limited, but may be a rough surface or a surface with minute steps, which can increase the retention of condensate. The surface roughness (ISO 25178) of the introduction surface can be measured, for example, using a laser microscope (model number: VK-X250) manufactured by Keyence Corporation. The arithmetic mean height Sa of this surface roughness is preferably 0.005 μm or more, more preferably 0.03 μm or more. The maximum height Sz is preferably 0.05 μm or more, more preferably 0.3 μm or more.

[0189] It is preferable that the introduction section 241 having the above-described configuration further has the following configuration. Figure 48(a) shows W 205 The width of the inner liquid flow path section 238 (the largest value in the direction in which the inner liquid flow path section 238 and the vapor flow path grooves 42 are arranged) is preferably 3000 μm or less, and may be 2000 μm or less, or may be 1500 μm or less. 205 The width W is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. 205The range of width W may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 205 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values.

[0190] Figure 48(a) shows W 207 The protrusion amount W (the distance from the end of the protrusion 39a to the apex 241a) is preferably 1000 μm or less, and may be 500 μm or less, or may be 300 μm or less. 207 The protrusion amount W is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. 207 The range of the protrusion amount W may be determined by a combination of any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 207 The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. Also, in Figure 48(a), T 203 The distance in the thickness direction from the top 241a of the convex portion 39a to the top 241a of the introduction portion 241, indicated by T 204 When T 203 T 204 The value obtained by dividing by is preferably 0.05 or more, may be 0.15 or more, or may be 0.3 or more. 203 T 204 The value obtained by dividing by 1.0 may be 0.8 or less, or 0.6 or less. 203 T 204 The range of values ​​obtained by dividing by T may be determined by combining any one of the plurality of upper limit candidate values ​​and one of the plurality of lower limit candidate values. 203 T 204 The range of values ​​divided by may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. In this embodiment, the value is 0.5, and the top portion 241a is disposed at the center of the inner liquid flow path portion 238 in the thickness direction.

[0191] Furthermore, as shown in FIG. 48(a), the width of the liquid flow channel groove 39 closest to the introduction portion 241 is set to W 209 The depth of the liquid flow channel groove 39 closest to the introduction portion 241 is D 201 , the protrusion amount of the introduction portion 241 on the surface 30b (the surface on which the liquid flow path groove 39 is not provided) is W 210 When this is the case, it is preferable that the following relationship holds: D 201 ×(W 209 / 2) <T 203 ×W 207 <(T 204 -T 203 )×W 210 This makes it easier for the condensed liquid working fluid to be collected in the condensate flow path 3, and makes it easier for the liquid working fluid to move between the steam flow path 4 and the condensate flow path 3. This also makes it easier for the liquid working fluid to evaporate in the steam flow path 4.

[0192] Next, we will explain the vapor chamber 1 when the first sheet 10, the second sheet, and the third sheet 30 are combined. Figures 49(a) and 49(b) show views corresponding to Figures 18(a) and 18(b). In the cross section shown in Figure 49(a), the steam flow path 4 and the steam flow path 3 are separated by a protrusion 39a, but the protrusion 39a has a communication opening 39b. Therefore, in the cross section shown in Figure 49(b), where the communication opening 39b is adjacent to the steam flow path 4, the steam flow path 4 and the steam flow path 3 are in communication with each other through the communication opening 39b.

[0193] As can be seen from Figures 49(a) and 49(b), the inner surface 10a of the first sheet 10 is superimposed on the first surface 30a side of the third sheet 30, and the inner surface 20a of the second sheet 20 is superimposed on the second surface 30b side of the third sheet 30, and they are joined together to form the vapor chamber 1.

[0194] By providing the introduction part 241, the introduction part 241 is disposed between the condensate flow path 3 and the steam flow path 4 and protrudes toward the steam flow path 4 side. In this embodiment, the introduction portion 241 has a top 241a that protrudes most toward the steam flow path 4 in the thickness direction (z direction), and is provided with an introduction surface 241b that is arc-shaped in cross section from the top 241a toward the side where the condensate flow path 3 is provided. That is, the introduction portion is disposed between the condensate flow path 3 and the steam flow path 4, protrudes toward the steam flow path 4, and has a surface (introduction surface) that includes a surface that approaches the condensate flow path 3 from its most protruding part (top).

[0195] The working fluid condenses as it loses heat while moving through the steam flow path 4 and adheres to the wall surface of the steam flow path 4. On the other hand, since steam flows continuously through the steam flow path 4, the condensed liquid adheres to the wall surface of the steam flow path 4 as shown by arrow C in Figures 49(a) and 49(b). 211 As shown by the arrows, the condensate moves to the condensate flow paths 3 as if being pushed by the steam. The condensate flow paths 3 are provided with communication openings 39b, so that the condensate is distributed to the plurality of condensate flow paths 3 through these communication openings. At this time, since the inlet portion 241 is provided on the inner surface of the steam flow path 4, a region is formed between the inlet surface 241b and the first sheet 10, and the condensate tends to accumulate there due to the action of capillary force. This allows the condensate to be introduced into the condensate flow path 3 more smoothly, and the amount of heat transport can be increased.

[0196] Here, it is preferable that the steam flow path 4, the introduction part 241, and the condensate flow path 3 have the following relationship. An explanatory diagram is shown in Figure 50. Note that some of the reference numerals are omitted in Figure 50 for ease of viewing, but Figure 49(a) can be referenced. In the same cross section as in FIG. 49(a), a rectangle having the distance between the opposing apexes 241a of the steam flow path 4 in the horizontal direction and the size of the steam flow path 4 in the thickness direction in the vertical direction is defined as region A, and its area is defined as A A Let's say. In the same cross section as in FIG. 49(a), the region of the steam flow path 4 surrounded by the inlet surface 241b, the region A, the protrusion 39a, and the first sheet 10 is referred to as region B, and the area of ​​this region is referred to as A. B Let's say. In the same cross section as in Figure 49(a), the area of ​​the condensate flow path 3 closest to area B is area C, and its area is A. C Let's say. These A A , A B , A C It is preferred that: A A >A B >A C This relationship makes it easier to draw condensed working fluid from the steam flow path 4 into the condensate flow path 3, and also prevents the sudden outflow of vaporized liquid from the condensate flow path 3 into the steam flow path 4.

[0197] 3.2. Form 3b to form 3h The following figures explain other embodiments, 3b to 3h, focusing on the shape of the introduction portion. All of these figures correspond to Figures 49(a) and 49(b). These introduction portion shapes can also be applied to the outer peripheral liquid flow path portion. For convenience, in each embodiment, reference numeral 238 denotes the inner liquid flow path portion, reference numeral 241 denotes the introduction portion, reference numeral 241a denotes the top, and reference numeral 241b denotes the introduction surface.

[0198] In the embodiment 3b of Fig. 51(a) and Fig. 51(b), the top portion 241a is disposed at a position closer to the condensate flow path 3 in the thickness direction than the top portion 41a of the embodiment 3a of Fig. 49(a) and Fig. 49(b). 203 T 204 The value obtained by dividing by this is in the range of 0.2 to 0.4. According to this configuration, the space between the introduction surface 141b and the first sheet 10 is small, so that the capillary force is likely to be strong, and the above-mentioned effect becomes more pronounced.

[0199] 52(a) and 52(b), the introduction surface 241b extending from the top portion 241a is linear in cross section. The introduction surface 241b in both the above-described embodiments 3a and 3b is arc-shaped and concave toward the inner liquid flow path section 238, but in embodiment 3c, the introduction surface 241b is linear in cross section. Even in this configuration, the above-mentioned effects can be achieved.

[0200] In form 3d of Figures 53(a) and 53(b), the top 241a is planar, and the introduction surface 241b has a surface that extends parallel to the direction in which the multiple condensate flow paths 3 and steam flow paths 4 are arranged (y direction). Even in this configuration, the above-mentioned effects can be achieved.

[0201] 54(a) and 54(b), the introduction surface 241b extending from the top 241a has an arc-like shape convex toward the steam flow path 4 in cross section. However, it does not have to be an arc-like shape, and may have a curved shape other than an arc-like shape convex toward the steam flow path 4 in cross section. Even in this configuration, the above-described effects can be achieved. In this configuration, it is possible to form a relatively large number of areas where the distance between the introduction surface 241b and the first sheet 10 is narrow as the introduction surface 241b approaches the condensate flow path 3, and it is expected that capillary force will be utilized efficiently.

[0202] In the configuration 3f of Figures 55(a) and 55(b), the apex 241a is provided at a distance up to the surface of the steam flow path 4 opposite to the condensate flow path 3. Even in this configuration, the introduction surface 241b can be formed, and the above-mentioned effect can be achieved. However, from the viewpoint of utilizing a stronger capillary force by narrowing the gap between the introduction surface and the first surface 10a, it is preferable that the top be positioned in the thickness direction on one of the side surfaces of the steam flow path that does not coincide with the inner surface facing in the thickness direction, as in each of the above-described embodiments.

[0203] In embodiment 3g of Figures 56(a) and 56(b), the condensate liquid flow paths 3 are formed on both sides of the inner liquid flow path section 238 in the thickness direction (i.e., in this respect, it is similar to embodiment 1). In this example, the introduction section 241 can form introduction surfaces 241b from its top 241a toward both condensate liquid flow paths 3, respectively, and the above-mentioned effects are exerted on each of the condensate liquid flow paths 3 present on both sides in the thickness direction.

[0204] In the configuration 3h of Figures 57(a) and 57(b), the condensate liquid flow path 3 is formed at the center in the thickness direction of the inner liquid flow path section 238. In this example, the vapor chamber is made up of two sheets. In this case, the first sheet 210 has the configuration of part of the first sheet 10 and third sheet 30 described above, and the second sheet 220 has the configuration of part of the second sheet 20 and third sheet 30 described above, and by combining the two, an enclosed space of the vapor chamber is formed. In this embodiment 3h, the introduction surface 241b extending from the top 241a of the introduction portion 241 has a surface that extends parallel to the direction in which the plurality of condensate flow paths 3 and steam flow paths 4 are arranged (y direction). Even in this configuration, the above-mentioned effects can be achieved.

[0205] In this embodiment, the top 241a and the condensate flow path 3 are at the same position in the thickness direction (position in the z direction), and the above-described embodiments have different positions in the thickness direction (position in the z direction) between the top and the condensate flow path. Either can be applied as needed, but there is a tendency that a larger amount of condensate can be retained and introduced when the positions in the thickness direction (position in the z direction) between the top and the condensate flow path are different.

[0206] 4. Form 4 In a vapor chamber, there is a risk that the working fluid may freeze in a temperature environment lower than the freezing point of the enclosed working fluid. In the case of a working fluid that expands upon freezing, such as pure water, the volume expansion of the working fluid in the vapor flow path may cause deformation of the vapor chamber. In cases where such a problem exists, it is preferable to have a configuration that can suppress deformation and provide more stable performance even when the working fluid freezes and expands. Therefore, in the fourth embodiment, a vapor chamber having a structure for this purpose will be described.

[0207] In form 4, the first sheet 10 and the second sheet 20 are different from those in forms 1 to 3. Therefore, the third sheet can be applied as described in forms 1 to 3 above, and therefore a description thereof will be omitted here. For convenience, an example in which the third sheet 30 of form 1 is applied will be described here, but the present invention is not limited to this. Therefore, the concept of placement in an electronic device, operation of the working fluid, and the resulting heat diffusion is as described above, and a description thereof will be omitted.

[0208] 4.1.Form 4a [form] Figure 58 shows a cross section of the vapor chamber 301 and is a view corresponding to Figure 15. As can be seen from Figure 58, the first sheet 310 has an inner sheet 311 and a reinforcing sheet 312, and the second sheet 320 has an inner sheet 321 and a reinforcing sheet.

[0209] The inner sheet 311 is a sheet disposed in contact with the first surface 30a of the third sheet 30, and constitutes the inner surface 10a. Similarly, the inner sheet 321 is a sheet disposed in contact with the second surface 30b of the third sheet 30, and constitutes the inner surface 20a. The reinforcing sheet 312 is a sheet that is arranged on the opposite side of the inner sheet 311 from the third sheet 30 side and constitutes the outer surface 10b. Similarly, the reinforcing sheet 322 is a sheet that is arranged on the opposite side of the inner sheet 321 from the third sheet 30 side and constitutes the outer surface 10b.

[0210] The inner sheet 311 and the reinforcing sheet 312 may be configured as a clad material. A clad material refers to a laminated material in which multiple types of sheets are bonded together. For example, the inner sheet 311 and the reinforcing sheet 312 may be fabricated as a clad material by plating one sheet onto the other sheet. In this case, an adhesion layer (strike plating layer, seed layer, etc.) (not shown) may be interposed between the two sheets to improve adhesion between them. Furthermore, the two sheets may be diffusion bonded to form a clad material. Similarly, the inner sheet 321 and the reinforcing sheet 322 may be configured as a clad material. A clad material refers to a laminated material in which multiple types of sheets are bonded together. For example, the inner sheet 321 and the reinforcing sheet 322 may be fabricated as a clad material by plating one sheet onto the other sheet. In this case, an adhesion layer (strike plating layer, seed layer, etc.) (not shown) may be interposed between the two sheets to improve adhesion between them. Furthermore, the two sheets may be diffusion bonded to form a clad material.

[0211] The material constituting the inner sheet 311 and the inner sheet 321 is not particularly limited as long as it has good thermal conductivity, but may contain, for example, copper or a copper alloy. In this case, the thermal conductivity of each sheet can be increased. This improves the heat dissipation efficiency of the vapor chamber 301. Furthermore, when pure water is used as the working fluid, corrosion can be prevented. However, other metal materials such as aluminum or titanium, or other metal alloy materials such as stainless steel can also be used as long as they can achieve the desired heat dissipation efficiency and prevent corrosion.

[0212] Reinforcing sheet 312 is made of a material with higher yield strength than inner sheet 311, and reinforcing sheet 322 is made of a material with higher yield strength than inner sheet 321. Here, yield strength is defined as the stress that results in a permanent distortion of 0.2% when unloaded. Although there are no particular limitations on the specific material of reinforcing sheets 312 and 322, it is preferable that the material be a metal material with good thermal conductivity and desired mechanical strength, and examples thereof include materials containing copper alloys, iron alloys, nickel, nickel alloys, titanium, titanium alloys, and aluminum alloys. Examples of iron alloys include stainless steel, invar material (iron alloy containing nickel), and kovar (iron alloy containing cobalt).

[0213] The thickness of the inner sheets 311 and 312 can be, for example, 0.2 μm or more and 100 μm or less. By making this thickness 0.2 μm or more, it is possible to prevent pinholes from being formed in the inner sheets 311 and 312 and to prevent impurities contained in the materials constituting the reinforcing sheets 312 and 322 from precipitating onto the third sheet 30 side through the pinholes. On the other hand, by making the thickness 100 μm or less, it is possible to prevent the thickness of the vapor chamber 301 from becoming too thick. The thickness of the inner sheets is more preferably 0.25 μm or more and 10 μm or less, and even more preferably 0.45 μm or more and 5 μm or less.

[0214] Furthermore, in order to enhance the reinforcing function, the thickness of reinforcing sheets 312 and 322 may be greater than the thickness of inner sheets 311 and 321. However, from the viewpoint of enhancing the reinforcing function, reinforcing sheet 321 is preferably thicker than inner sheet 311, and more specifically, the thickness of the reinforcing sheets is preferably 5 to 30 times, and more preferably 5 to 20 times, the thickness of the inner sheets. The specific thickness of reinforcing sheet 312 and reinforcing sheet 322 is not particularly limited, but is, for example, 3 μm or more and 100 μm or less. By making this thickness 3 μm or more, effective reinforcement can be achieved. On the other hand, by making it 100 μm or less, an increase in the thickness of vapor chamber 301 can be prevented. A thickness of 5 μm or more and 50 μm or less is more preferable, and a thickness of 9 μm or more and 25 μm or less is even more preferable.

[0215] The thickness of the first sheet 310 and the second sheet 320 is 0.1 mm or less, preferably 0.05 mm or less, and more preferably 0.02 mm or less. This makes it possible to manufacture a thin vapor chamber (e.g., 0.4 mm or less) that is less susceptible to freezing expansion. On the other hand, the thickness of the first sheet 310 and the second sheet 320 is, for example, 0.01 mm or more. This makes it possible to suppress deformation of the inner sheet 311 and the inner sheet 321 due to freezing expansion of the working fluid in the vapor flow path 4.

[0216] In addition, in this embodiment, both the first sheet 310 and the second sheet 320 are provided with both an inner sheet and a reinforcing sheet, however, this is not limited to this, and if not necessary, a reinforcing sheet may be provided on only either the first sheet or the second sheet.

[0217] Furthermore, a layer of the same material and thickness as the inner sheet may be laminated on at least one of the reinforcing sheet 312 of the first sheet 310 and the reinforcing sheet 322 of the second sheet 320. This makes it possible to suppress warping in the sheet on which this layer is laminated.

[0218] [Manufacturing method] Next, a method for manufacturing the vapor chamber 301 having such a configuration will be described with reference to FIGS.

[0219] First, as shown in FIG. 59, in a preparation step, a flat metal material sheet M including a first surface Ma and a second surface Mb is prepared.

[0220] 60, as a resist formation step, a resist film 340 is formed on the first surface Ma of the metal material sheet M, and a resist film 341 is formed on the second surface Mb. Before forming the resist films 340 and 341, the first surface Ma and the second surface Mb of the metal material sheet M may be subjected to an acid degreasing treatment as a pretreatment.

[0221] Next, as shown in FIG. 61, in a patterning step, the resist film 340 and the resist film 341 are patterned by photolithography. The resist film 340 is patterned to form openings corresponding to the liquid flow path grooves 39 and communicating openings 39b of the inner liquid flow path 38, and the vapor flow path grooves 42. At this time, the openings corresponding to the liquid flow path grooves 39 and communicating openings 39b can be formed so that they are smaller in width than the liquid flow path grooves 39 and communicating openings 39b. On the other hand, the opening corresponding to the vapor flow path groove 42 can be formed so that it has the same width as the vapor flow path groove 42 on the first surface 30a. On the other hand, the resist film 341 is patterned to form openings corresponding to the liquid flow path grooves 40, the communicating openings 40b, and the vapor flow path grooves 42 of the inner liquid flow path 38. At this time, the openings corresponding to the liquid flow path grooves 40 and the communicating openings 40b can be formed so as to have widths smaller than the liquid flow path grooves 40 and the communicating openings 40b. On the other hand, the opening corresponding to the vapor flow path groove 42 can be formed so as to have the same width as the vapor flow path groove 42 on the second surface 30b.

[0222] 62, in an etching step, the first surface 30a and the second surface 30b of the metal material sheet M are etched. As a result, the portions of the metal material sheet M corresponding to the openings where the resist film 340 and the resist film 341 are formed are etched, and liquid flow path grooves 39, communicating openings 39b, liquid flow path portions 40, communicating openings 40b, and vapor flow path grooves 42 are formed. Note that, as the etching solution, for example, an iron chloride-based etching solution such as a ferric chloride aqueous solution, or a copper chloride-based etching solution such as a copper chloride aqueous solution can be used.

[0223] As described above, if the openings in the resist films 340 and 341 corresponding to the liquid flow path groove 39, the communicating openings 39b, the liquid flow path groove 40, and the communicating openings 40b are formed with widths smaller than the width of the grooves, the amount of etching liquid that enters the openings is reduced, and the etching rate in these portions is decreased. Therefore, the depths of the liquid flow path groove 39, the communicating openings 39b, the liquid flow path groove 40, and the communicating openings 40b can be made shallow. On the other hand, if the openings in the resist films 340 and 341 corresponding to the vapor flow path groove 42 are formed with the same width as the vapor flow path groove 42 on the first surface 30a and the second surface 30b, the amount of etching liquid that enters the openings can be secured, and the etching depth required to form the vapor flow path groove 42 can be secured (as a result, the vapor flow path groove 42 penetrates the thickness direction).

[0224] Furthermore, to form a portion in which the groove does not penetrate in the thickness direction, such as the connecting portion 44c shown in Figure 6 or other means for holding the inner liquid flow path portion 38, the depth of that portion can be reduced by adjusting the width of the resist film, or an opening can be provided in only one of the resist films arranged on both sides of the metal material sheet M.

[0225] After the etching step, as shown in FIG. 63, the resist film 340 and the resist film 341 are removed in a resist removal step.

[0226] In this way, the third sheet 30 can be obtained.

[0227] As a preparation step for the first sheet 310, a reinforcing sheet 312 is attached to the inner sheet 311. As a preparation step for the laminated sheet and the second sheet 320, a sheet is prepared in which a reinforcing sheet 322 is laminated on an inner sheet 321. The method for each preparation step is not particularly limited, but a material manufactured as a clad material can be used. Alternatively, the inner sheets 311, 312 may be formed by plating the reinforcing sheets 311, 322 formed from rolled material. In this case, an adhesion layer may be interposed between the reinforcing sheets 312, 322 and the inner sheets 311, 321 to improve the bonding between them. Examples of adhesion layers include a strike-plated layer and a seed layer. For example, if the reinforcing sheets 312, 322 are formed from stainless steel and the inner sheets 311, 321 are formed from copper, a strike-plated layer containing a material such as nickel or copper may be interposed. Alternatively, a seed layer containing a material such as titanium or molybdenum may be interposed by sputtering. The thickness of the strike-plated layer and the seed layer is, for example, in the range of 10 nm to 1000 nm. Alternatively, the inner sheets 311, 321 may be formed from rolled material, and the reinforcing sheets 312, 322 may be formed by plating. Furthermore, one of the inner sheets 311, 321 and the reinforcing sheets 312, 322 may be formed by plating, and the other may be laminated by further plating.

[0228] After the third sheet 30, the first sheet 310, and the second sheet 320 are prepared, they are temporarily fixed in a stacked state in a temporary fixing step. The method of fixing for temporary fastening is not particularly limited, but can be, for example, resistance welding. In this case, resistance welding can be performed in spots using an electrode rod (not shown). Laser welding can also be performed instead of resistance welding.

[0229] After the temporary joining process, as shown in Figure 64, the first sheet 310, the second sheet 320, and the third sheet 30 are permanently bonded by diffusion bonding in the bonding process. Diffusion bonding is a method in which the first sheet 310 and the third sheet 30, and the third sheet 30 and the second sheet 320 are bonded together, and then pressure is applied in the stacking direction and heat is applied in a controlled atmosphere such as a vacuum or an inert gas, to bond the sheets by utilizing atomic diffusion that occurs at the bonding surfaces. Diffusion bonding heats the materials that make up each sheet to a temperature close to, but lower than, the melting point, preventing the sheets from melting and deforming.

[0230] After the joining process, a sealing process is performed in which the working fluid is sealed into the hollow space through the injection portion. After the working fluid is injected, the injection flow path is sealed. For example, the injection portion may be irradiated with a laser to partially melt the injection portion and seal the injection flow path. This isolates the space in which the working fluid is sealed from the outside. For sealing, the injection portion may be crimped (pressed to cause plastic deformation) or brazed.

[0231] In this manner, the vapor chamber 301 is obtained. In this example, the first and second sheets are plated and then stacked, but this is not limiting; plating may be performed after stacking the sheets. In this case, a plated layer is also formed on the side surfaces.

[0232] [Vapor chamber function] The operational process for cooling the heat source in the vapor chamber 301 is the same as that described above, and therefore will not be described here. On the other hand, electronic devices equipped with vapor chamber 301 may be placed in a temperature environment below the freezing point of the working fluid. In this case, the working fluid freezes, and depending on the type of working fluid, freezing causes it to expand. For example, if the working fluid is pure water, it may freeze and expand in a sub-zero environment. This expansion may apply a force in the direction that expands vapor chamber 301 in the thickness direction in the portion where the working fluid is stored.

[0233] In contrast, in vapor chamber 301, first sheet 310 is provided with reinforcing sheet 312, and second sheet 320 is provided with reinforcing sheet 322. This reinforces first sheet 310 and second sheet 320, preventing deformation even when subjected to the force caused by the freezing and expansion of the working fluid. This prevents a decrease in the flatness of the contact surface with the heat source at the portion receiving heat from the heat source and the contact surface with a component (e.g., a housing) at the portion releasing heat to the outside, thereby preventing the formation of gaps. This prevents the conduction of heat from the heat source to vapor chamber 301 and from vapor chamber 301 to the outside from being impeded.

[0234] Furthermore, if the thickness of the reinforcing sheet 312 is made thicker than the thickness of the inner sheet 311 and the thickness of the reinforcing sheet 322 is made thicker than the thickness of the inner sheet 321, the inner sheets 311 and 321 can be further reinforced by the reinforcing sheets 312 and 322, and deformation of the vapor chamber 301 can be further suppressed.

[0235] 4.2.Form 4b Next, mode 4b will be described. FIG. 65 shows a diagram for explaining vapor chamber 301', and FIG. 66 shows a diagram for explaining vapor chamber 301'', both of which are cross-sectional views corresponding to FIG.

[0236] In the vapor chamber 301' shown in Figure 65, the third sheet 30 is not disposed, and the first sheet 310' and the second sheet 320' are directly laminated together. That is, the vapor chamber 301' is configured by overlapping and joining the inner sheet 311' of the first sheet 310' and the inner sheet 321' of the second sheet 320'. However, in this embodiment, grooves are formed on the overlapping surfaces of the inner sheet 311' and the inner sheet 321', thereby forming the condensate flow paths 3 and the steam flow paths 4. The concept behind the shapes of the condensate flow paths 3 and the steam flow paths 4 is the same as above. Even in this configuration, since the reinforcing sheets 312, 322 are provided, the same effects as those described above can be achieved.

[0237] The vapor chamber 301'' shown in Figure 66 also does not have a third sheet 30, and the first sheet 310'' and the second sheet 320'' are directly laminated together.In other words, the inner sheet 311'' of the first sheet 310'' and the inner sheet 321'' of the second sheet 320'' are overlapped and joined together. In this embodiment, the condensate flow path 3 is not provided between adjacent steam flow paths 4, but rather the condensate flow path 3 and the steam flow path 4 are provided in the same flow path. Therefore, in this embodiment, a capillary structure member 339 is arranged in the same flow path as the flow path that becomes the steam flow path 4. This capillary structure member 339 is configured as a capillary structure (wick) through which the liquefied working fluid flows. The capillary structure member 339 can be configured, for example, from a metal mesh, metal powder, or twisted metal wire. Even in this configuration, since the reinforcing sheets 312, 322 are provided, the same effects as those described above can be achieved.

[0238] 5. Form 5 The vapor chamber 401 of embodiment 5 is an example in which a first sheet 410 and a second sheet 420 are applied instead of the first sheet 310 and the second sheet 320 provided in the vapor chamber 301 described in embodiment 4. Furthermore, this first sheet 410 differs from the first sheet 310 in that a barrier sheet 413 is disposed between the inner sheet 311 and the reinforcing sheet 312 described in the first sheet 310. Furthermore, the second sheet 420 differs from the second sheet 320 in that a barrier sheet 423 is disposed between the inner sheet 321 and the reinforcing sheet 322 described in the first sheet 320. Therefore, the components other than the barrier sheets 413 and 423 can be considered to be the same as the vapor chamber 301 of form 4, and therefore only the barrier sheets 413 and 423 will be described here.

[0239] The barrier material constituting the barrier sheets 413, 423 is not particularly limited as long as it can prevent the metal elements constituting the reinforcing sheets 312, 322 from permeating toward the inner sheets 311, 321. Such a barrier material may include, for example, at least one of tungsten (W), titanium (Ti), tantalum (Ta), and molybdenum (Mo). The barrier material may be composed of only one of tungsten, titanium, tantalum, and molybdenum. In this case, the barrier sheets 413, 423 are formed as a single-phase film. Alternatively, the barrier material may be composed of a combination of any two or more materials selected from tungsten, titanium, tantalum, and molybdenum. In this case, the barrier sheets 413, 423 are formed as an alloy film. An example of such an alloy film is a tungsten-titanium alloy film. The barrier material may also be a combination of the above-mentioned four metal elements and other metal elements. In this case, an example of the alloy film is a nickel-tungsten alloy film.

[0240] The thickness of the barrier sheets 413, 423 is arbitrary as long as it can exhibit its barrier function. The thickness of the barrier sheets 413, 423 is, for example, in the range of 10 nm to 1000 nm. By making the thickness of the barrier sheets 413, 423 10 nm or more, it is possible to effectively prevent the metal elements constituting the reinforcing sheets 312, 322 from penetrating. On the other hand, by making the thickness 1000 nm or less, it is possible to easily manufacture the barrier sheets 413, 423 by a sputtering process and to prevent the vapor chamber 401 from becoming too thick. Furthermore, by making the thickness 1000 nm or less, it is possible to prevent the heat conduction from being hindered. From the viewpoint of more effectively exhibiting the barrier function, it is preferable that the thickness of the barrier sheets be 100 nm or more.

[0241] Here, a method for confirming the components of the barrier sheets 413, 423 will be described. First, the presence or absence of the barrier sheets 413, 423 can be confirmed, for example, by cutting the vapor chamber 401 at an arbitrary position and imaging the cross section obtained with a scanning electron microscope (SEM). The components of the barrier sheets 413, 423 may be confirmed, for example, by scraping off a small portion of the lower surface of the vapor chamber 401, analyzing the scraped-off components with energy dispersive X-ray analysis (EDX), and then scraping off some more material for further component analysis. By repeating the component analysis in this manner, the components of the barrier sheets 413, 423 can be confirmed.

[0242] An adhesion layer may be formed between the barrier sheets 413, 423 and the inner sheets 311, 321 to improve the bonding between them. When an adhesion layer is formed, the adhesion layer is first formed on the surface of the barrier sheets 413, 423, and then the inner sheets 311, 321 are formed on the surface of the adhesion layer. Examples of adhesion layers include a strike-plated layer and a seed layer. For example, if the barrier sheets 413, 423 are formed of a material containing molybdenum and the inner sheets 311, 321 are formed of copper, a seed layer containing copper may be interposed by sputtering using a sputtering target material containing copper. The thickness of the strike-plated layer and the seed layer may be, for example, in the range of 50 nm to 500 nm. Alternatively, the cover sheets 413, 423 may be formed from a rolled material, and the reinforcing sheets 312, 322 may be formed by plating. Furthermore, one of the cover sheets 413, 423 and the reinforcing sheets 312, 322 may be formed by plating, and the other may be laminated by further plating.

[0243] In addition to the same effects as those of the vapor chamber 301 described in the fourth embodiment, such vapor chamber 401 can prevent the metal material forming the reinforcing sheet from diffusing into the inner sheet.

[0244] 6.Form 6 In Form 6, the shape of the liquid flow path groove in the third sheet is different from that of the vapor chambers in Forms 1 to 5 described so far. Since the other parts can be considered to be the same as those in Forms 1 to 5, the explanation here focuses on the inner liquid flow path portion and omits explanation of the other parts. However, a similar shape can also be applied to the outer peripheral liquid flow path portion. For convenience, the parts common to the first to fifth embodiments are given the symbols of the first embodiment, but the second to fifth embodiments can also be applied to the common parts.

[0245] 6.1.Form 6a Fig. 68 is a view of the inner liquid flow path section 538 of the vapor chamber 501 of this embodiment as seen from the z direction, and is a view from the same perspective as Fig. 14. As can be seen from Fig. 68, the inner liquid flow path section 538 has a liquid flow path groove 551 extending in the x direction, and liquid flow path convex sections 552 which are a pair of convex sections adjacent to each other with the liquid flow path groove 551 interposed therebetween. The liquid flow path groove 551 is configured mainly to transport a liquid working fluid.

[0246] The pair of liquid flow path convex portions 552 are composed of a first liquid flow path convex portion 552A arranged on one side (the y direction side in the figure) of liquid flow path groove 551, and a second liquid flow path convex portion 552B arranged on the opposite side (the opposite side to the y direction in the figure) of liquid flow path groove 551. A plurality of first liquid flow path convex portions 552A are arranged in a first direction (the x direction in the figure) to form a first liquid flow path convex portion row 553A, and similarly, a plurality of second liquid flow path convex portions 552B are arranged in the first direction (the x direction in the figure) to form a second liquid flow path convex portion row 553B.

[0247] Furthermore, a first communication groove 554A is formed between each of the first liquid flow path protrusions 552A arranged in the first direction (x direction in the figure), and similarly, a second communication groove 554B is formed between each of the second liquid flow path protrusions 552B arranged in the first direction (x direction in the figure). Each of the first communication grooves 554A and each of the second communication grooves 554B are connected to the liquid flow path groove 551.

[0248] The working fluid loses heat from its vapor state and condenses into liquid on the surface of the vapor flow groove 42 (vapor flow path 4). The working fluid then flows from the surface of the vapor flow groove 42 (vapor flow path 4) into the first connecting groove 554A and the second connecting groove 554B by capillary action, and then further flows into the liquid flow path groove 551 (condensed liquid flow path 3) by capillary action.

[0249] In the example shown in FIG. 68, the plurality of first liquid flow path protrusions 552A constituting the first liquid flow path protrusion row 553A are arranged at a constant pitch P 501 Similarly, the plurality of second liquid flow path protrusions 552B constituting the second liquid flow path protrusion row 553B are also arranged at a constant pitch P 501 are arranged in the first direction (x direction).

[0250] By setting the pitch at a constant value in this manner, the design of first liquid flow path protrusion row 553A and second liquid flow path protrusion row 553B does not need to be complicated. It is also expected that the action of each pair of liquid flow path protrusions 552 will be equalized. For example, it is expected that the ease with which the liquid working fluid will enter liquid flow path groove 551 from each of the plurality of first communication grooves 554A and the plurality of second communication grooves 554B will be equalized. However, the plurality of first liquid flow path convex portions 552A and the plurality of second liquid flow path convex portions 552B do not have to be arranged at a constant pitch.

[0251] In addition, in the example shown in Figure 68, the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B adjacent to each other via the liquid flow path groove 551 are formed symmetrically with respect to the liquid flow path groove 551.

[0252] By making them line-symmetrical in this way, the design of first liquid flow path protrusion row 553A and second liquid flow path protrusion row 553B does not become complicated. It is also expected that the action of each pair of liquid flow path protrusions 552 can be equalized. For example, it is expected that the ease with which the liquid working fluid can enter liquid flow path groove 551 from each of the plurality of first communication grooves 554A and the plurality of second communication grooves 554B can be equalized.

[0253] However, in this embodiment, the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B adjacent to each other via the liquid flow path groove 551 do not have to be formed line-symmetrically with respect to the liquid flow path groove 551.

[0254] The first liquid flow path convex portion 552A extends in a direction oblique to the first direction (the x direction in the figure) while proceeding from one side of the liquid flow path groove 551 (the y direction side in the figure) toward the liquid flow path groove 551, and the second liquid flow path convex portion 552B extends in a direction oblique to the first direction while proceeding from the opposite side of the liquid flow path groove 551 (the opposite side to the y direction in the figure) toward the liquid flow path groove 551. Furthermore, the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B constituting the pair of liquid flow path convex portions 552 on the first direction side is shorter than the distance on the opposite side from the first direction side.

[0255] The configurations and functions of the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B will be described in more detail with reference to FIGS.

[0256] First, the shapes of the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B will be described. Fig. 69 is a diagram illustrating the shape of the pair of liquid flow path convex portions 52 shown in Fig. 68. In the example shown in Fig. 69, the first liquid flow path convex portion 552A has a planar shape of a parallelogram formed by four points P1, Q1, R1, and S1, and the side connecting P1 and Q1 forms an angle θ1 with the first direction (x direction). The angle θ1 can be in the range of greater than 0° and less than 90°, but is preferably 30° or greater and 60° or less.

[0257] As described above, the first liquid flow path convex portion 552A has a configuration in which it extends in a direction oblique to the first direction (x direction) while proceeding from one side (y direction side in the figure) of the liquid flow path groove 551 toward the liquid flow path groove 551. Therefore, the first communication groove 554A (portion surrounded by a dashed line in the figure) formed between the first liquid flow path convex portions 552A arranged in the first direction (x direction) also has a configuration in which it extends in a direction oblique to the first direction while proceeding from one side (y direction side) of the liquid flow path groove 551 toward the liquid flow path groove 551.

[0258] Similarly, the second liquid flow path protrusion 552B has a planar shape of a parallelogram formed by four points P2, Q2, R2, and S2, and the side connecting P2 and Q2 forms an angle θ2 with the first direction (x direction). The angle θ2 can also be in the range of greater than 0° and less than 90°, but is preferably between 30° and 60°.

[0259] As described above, second liquid flow path convex portion 552B has a configuration in which it extends in a direction oblique to the first direction so as to proceed from the opposite side (opposite side to the y direction) from the one side of liquid flow path groove 551 toward liquid flow path groove 551 and in the first direction. Therefore, second communication groove 554B (portion surrounded by dashed line in the figure) formed between second liquid flow path convex portions 552B arranged in the first direction (x direction) also has a configuration in which it extends in a direction oblique to the first direction so as to proceed in the first direction (x direction) from the opposite side (opposite side to the y direction) from the one side of liquid flow path groove 551 toward liquid flow path 551.

[0260] 69, similarly to Fig. 68, a first liquid flow path convex portion 552A and a second liquid flow path convex portion 552B adjacent to each other via a main flow path groove 551 are formed line-symmetrically with respect to the liquid flow path groove 551, respectively. In this case, the above-mentioned angles θ1 and θ2 are equal. Also in this case, the first communication groove 554A and the second communication groove 554B are also line-symmetric with respect to the liquid flow path 551.

[0261] By making them line-symmetrical in this way, the design of first liquid flow path protrusion row 553A and second liquid flow path protrusion row 553B does not become complicated. It is also expected that the action of each pair of liquid flow path protrusions 552 can be equalized. For example, it is expected that the ease with which the liquid working fluid can enter liquid flow path groove 551 from each of the plurality of first communication grooves 554A and the plurality of second communication grooves 554B can be equalized.

[0262] However, in this embodiment, the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B constituting the pair of liquid flow path convex portions 552 do not have to be formed line-symmetrically with respect to the liquid flow path groove 551. When they are not formed line-symmetrically, for example, the following effects can be achieved.

[0263] For example, if vapor of the working fluid flows into or is generated in a region sandwiched between a pair of liquid flow path convex portions 552, it is necessary to prevent the vapor from entering the evaporation portion (a portion close to the heat source). Here, in this embodiment, even if the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B constituting the pair of liquid flow path convex portions 552 are not formed line-symmetrically with respect to the liquid flow path groove 551, even if the vapor of the working fluid attempts to proceed in the first direction (x direction), it is blocked by the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B, reducing the momentum of the vapor proceeding in the first direction (x direction), thereby preventing the vapor from proceeding to the evaporation portion. The functions of the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B will be described in more detail later using FIG. 70.

[0264] Furthermore, in vapor chamber 501 according to this embodiment, the distance on the first direction side between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B constituting a pair of liquid flow path convex portions 552 is shorter than the distance on the opposite side from the first direction side. For example, as shown in Fig. 69, in first liquid flow path convex portion 552A (a parallelogram formed by four points P1, Q1, R1, and S1) and second liquid flow path convex portion 552B (a parallelogram formed by four points P2, Q2, R2, and S2), the distance D1 between the ends on the first direction (x-direction) side (the distance between S1 and S2) is shorter than the distance D2 between the ends on the opposite side from the first direction (x-direction) side (the distance between R1 and R2).

[0265] Next, the operation of the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B having the above-described configuration will be described. Fig. 70 is a diagram for explaining the operation of the pair of liquid flow path convex portions 552 shown in Fig. 69, and is a diagram for mainly explaining the flow of the liquid working fluid and the flow of the vapor working fluid in this configuration. Here, in Fig. 70, the flow of the liquid working fluid is indicated by a thick solid arrow, and the flow of the vapor working fluid is indicated by a thick dashed arrow.

[0266] First, the flow of the liquid working fluid shown in FIG. 70 will be described. As explained using Figure 69, the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B that constitute a pair of liquid flow path convex portions 552 have a configuration in which they extend in a direction inclined with respect to the first direction, and the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B on the first direction side is smaller than the distance on the opposite side from the first direction side.

[0267] Therefore, as shown by the thick solid arrow in Figure 70, the liquid working fluid present in the area sandwiched between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B that make up a pair of liquid flow path convex portions 552 will, by capillary action, move from the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is greater to the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is smaller.

[0268] In other words, in this embodiment, a stronger propulsive force can be applied to the liquid working fluid present in the area sandwiched between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B that constitute a pair of liquid flow path convex portions 552, thereby transporting it in the first direction (x direction).

[0269] In addition, in this embodiment, the depth of the area sandwiched between a pair of liquid flow path convex portions 552 can be configured such that the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is greater is deeper than the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is smaller.

[0270] By adopting such a configuration, a larger amount of liquid working fluid can be stored in this region. As described above, the liquid working fluid present in this region can be transported in the first direction (x direction) (i.e., toward the evaporation section V) with a stronger driving force. Therefore, it is possible to prevent a shortage of liquid working fluid in the evaporation section (region 4 close to the object to be cooled).

[0271] Furthermore, with the above configuration, the depth of the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is smaller is shallower, that is, the flow path cross-sectional area of ​​the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is smaller than that of the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is larger, resulting in stronger capillary action. Therefore, a stronger driving force is applied to the liquid working fluid in liquid flow path groove 551, causing it to be transported in the first direction (x direction) through liquid flow path groove 551 (condensate flow path 3) of inner liquid flow path portion 538.

[0272] In addition, the liquid working fluid that passes through the end where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is shorter will diffuse in the area sandwiched between the next pair of liquid flow path convex portions 552, but due to the pressure of this diffusion and the volume of liquid working fluid present in the area sandwiched between the pair of liquid flow path convex portions 552, it is possible to more effectively prevent the working fluid vapor from entering the liquid flow path groove 551 (condensate liquid flow path 3) from the first communication groove 554A and the second communication groove 554B.

[0273] The above-described configuration can be obtained, for example, by forming the liquid flow path portion 50 by half-etching using an etching liquid. In half-etching using an etching liquid, a larger etched area tends to be etched deeper than a smaller etched area.

[0274] Therefore, for example, the etching pattern used to form inner liquid flow path portion 538 is an etching pattern in which the area of ​​the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is greater (the above-mentioned D2 side) is greater than the area of ​​the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is smaller (the above-mentioned D1 side) with respect to the region sandwiched between a pair of liquid flow path convex portions 552. This allows the depth of the region sandwiched between a pair of liquid flow path convex portions 552 formed by half etching using an etching liquid to be greater on the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is greater (the above-mentioned D2 side) than on the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is smaller (the above-mentioned D1 side).

[0275] Next, the flow of the working fluid, which is steam, will be described. As explained with reference to Fig. 69, first liquid flow path convex portion 552A and second liquid flow path convex portion 552B, and first communication groove 554A and second communication groove 554B have a configuration in which they extend in a direction inclined with respect to the first direction. Therefore, the vapor of the working fluid (indicated by the dashed arrow in the figure) that passes through vapor flow path groove 42 (vapor flow path 4) and diffuses in the direction opposite to the first direction (x direction) is unlikely to enter liquid flow path groove 551 (condensate flow path 3) through first communication groove 554A and second communication groove 554B, which are generally opposite to the diffusion direction.

[0276] That is, as shown in FIG. 68, the evaporation section (the portion close to the cooling target) 4 is located on the upper side (x-direction side) in FIG. 70, and therefore, in FIG. 70, the vapor pressure is high on the upper side (x-direction side) and low on the lower side (opposite the x-direction). Therefore, the vapor of the working fluid is unlikely to diffuse from the lower side (opposite the x-direction), where the pressure is low, to the upper side (x-direction), where the pressure is high. In other words, the vapor of the working fluid is unlikely to flow from the lower side (opposite the x-direction) to the upper side (x-direction) through the first communication groove 554A or the second communication groove 554B.

[0277] Furthermore, as described above, the liquid working fluid that has passed through the end portion on the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is shorter will diffuse in the region sandwiched between the next pair of liquid flow path convex portions 552. Therefore, the pressure of this diffusion and the volume of liquid working fluid present in the region sandwiched between the pair of liquid flow path convex portions 552 can more effectively prevent vapor of the working fluid from entering liquid flow path groove 551 (condensate flow path 3) from first communication groove 554A and second communication groove 554B.

[0278] Therefore, the vapor chamber 501 of this embodiment effectively prevents the working fluid in vapor state from entering the liquid flow path groove 551 (condensate flow path 3) from the first communication groove 554A or the second communication groove 554B, thereby improving the transport function of the liquid working fluid and improving heat transport efficiency.

[0279] Furthermore, the pressure of the steam immediately (at the moment) after the inflow of vapor of the working fluid into the liquid flow path groove 551 (condensate flow path 3) or the sudden boiling of the liquid working fluid (i.e., the generation of vapor) occurs is higher on the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B of the pair of liquid flow path convex portions 552 is shorter, and lower on the other sides (the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is longer, and the side of the first communication groove 554A and the side of the second communication groove 554B).

[0280] Therefore, steam that flows into or is generated in the region sandwiched between the pair of liquid flow path convex portions 552 is more likely to move toward the other side (the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is greater, or the side toward the first communication groove 554A and the second communication groove 554B) than toward the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B of the pair of liquid flow path convex portions 552 is smaller. In other words, steam that flows into or is generated in the region sandwiched between the pair of liquid flow path convex portions 552 is less likely to move in the first direction (x direction) within the liquid flow path groove 551 (condensate liquid flow path 3).

[0281] Therefore, according to the vapor chamber 501 of this embodiment, when the temperature of the evaporation section V is high and evaporation is active, even if steam flows into or is generated within the liquid flow path groove 551 (condensate flow path 3), this flowing in or generated steam can be prevented from traveling in the first direction (x direction) within the liquid flow path groove 551 (condensate flow path 3), thereby improving the transport function of the liquid working fluid and improving heat transport efficiency.

[0282] As described above, steam that flows into or is generated in the area sandwiched between a pair of liquid flow path convex portions 552 is more likely to proceed to other sides (the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B is larger, or the side of the first connecting groove 554A and the side of the second connecting groove 554B) than to proceed to the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B of the pair of liquid flow path convex portions 552 is smaller.

[0283] Here, since the pressure is high on the side where the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B of a pair of liquid flow path convex portions 552 located on the opposite side of the first direction (x direction) of the pair of liquid flow path convex portions 552 into which steam flows or is generated is smaller, it is unlikely that steam will pass through this high pressure area and flow into the pair of liquid flow path convex portions 552 located on the opposite side of the first direction (x direction).

[0284] Therefore, the steam is discharged to the steam flow path groove 42 (steam flow path 4) through the first communication groove 554A and the second communication groove 554B. Here, by designing the widths of the first communication groove 554A and the second communication groove 554B to be larger than the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B of the pair of liquid flow path convex portions 552, the steam discharge effect can be further enhanced.

[0285] Next, the planar shapes (particularly corners) of first liquid flow path convex portion 552A and second liquid flow path convex portion 552B will be described in detail with reference to Figure 71. As will be described later, inner liquid flow path portion 538 is formed by half-etching a metal material sheet using an etching solution. Therefore, the planar shapes of first liquid flow path convex portion 552A and second liquid flow path convex portion 552B that make up a pair of liquid flow path convex portions 552 are not strictly parallelograms, but have rounded corners.

[0286] For example, as shown in Fig. 71, first liquid flow path convex portion 552A is a parallelogram (parallelogram shown by solid lines in Fig. 71) formed by four points P1, Q1, R1, and S1, with sharp corners rounded to have curved portions 555 and 556 shown by dashed lines. However, as long as side 557 in the direction of the line connecting P1 and Q1 and side 558 in the direction of the line connecting S1 and R1 remain, the various effects described above can be achieved in vapor chamber 501 of this embodiment. The same applies to second liquid flow path convex portion 552B.

[0287] 6.2.Form 6b Next, a vapor chamber according to embodiment 6b will be described with reference to FIG. The vapor chamber according to form 6b differs from the vapor chamber according to form 6a in the form of its inner liquid flow path portion, but other configurations can be the same as those of the vapor chamber according to form 6a.

[0288] Fig. 72 is a diagram showing an example of an inner liquid flow path portion 538' of a vapor chamber 501' according to embodiment 6b. More specifically, Fig. 72 is a diagram corresponding to Fig. 69 showing the vapor chamber 501'.

[0289] The liquid flow path portion of the vapor chamber in this embodiment has a plurality of liquid flow path grooves, each extending in a first direction through which a liquid working fluid passes, and a plurality of convex portion rows extending in the first direction with the liquid flow path grooves interposed therebetween, the plurality of liquid flow path grooves including a single reference liquid flow path groove, each of the convex portion rows including a plurality of liquid flow path convex portions arranged in the first direction via a plurality of communication grooves, the plurality of communication grooves including a first communication groove arranged on one side of the reference main groove and a second communication groove arranged on the other side of the reference main groove, the first communication groove extending in a direction inclined with respect to the first direction so as to proceed in the first direction while proceeding toward the reference main groove, and the second communication groove extending in a direction inclined with respect to the first direction so as to proceed in the first direction while proceeding toward the reference liquid flow path groove.

[0290] Furthermore, the first communication grooves are aligned in the direction in which the first communication grooves extend, and the second communication grooves are aligned in the direction in which the second communication grooves extend.

[0291] 72, an inner liquid flow path portion 538′ of a vapor chamber 501′ has three liquid flow path grooves (551′, 551′A, 551′B) including a reference liquid flow path groove 551′. Each liquid flow path groove extends in a first direction (x direction).

[0292] The internal liquid flow path section 538' of the vapor chamber 501' has four convex rows (553'A, 553'B, 553'C, 553'D) extending in the first direction. Of the four convex rows (553'A, 553'B, 553'C, 553'D), the convex row on one side of the reference main flow groove 551 (the Y direction side in the drawing) is the first convex row (553'A, 553'B), and the convex row on the other side of the reference liquid flow path groove 551' (the opposite side to the y direction in the drawing) is the second convex row (553'D, 553'C).

[0293] To put it more simply, in the example shown in Figure 72, the first convex row 553'A, the liquid flow path groove 551'A, the first convex row 553'B, the reference main groove 551', the second convex row 553'D, the liquid flow path groove 551'B, and the second convex row 553'C are arranged in order from the y direction in the figure.

[0294] The first convex portion row 553'A includes a plurality of liquid flow path convex portions 552'A arranged in the first direction (x direction) via a plurality of first communication grooves 554'A. Similarly, the first convex portion row 553'B includes a plurality of liquid flow path convex portions 552'B arranged in the first direction via a plurality of first communication grooves 554'B. Furthermore, the second convex portion row 553'D includes a plurality of liquid flow path convex portions 552'D arranged in the first direction via a plurality of second communication grooves 554'D. Furthermore, the second convex portion row 553'C includes a plurality of liquid flow path convex portions 552'C arranged in the first direction via a plurality of second communication grooves 554'C.

[0295] Each of the first communication grooves 554'A, 554'B extends in a direction inclined relative to the first direction (x direction) while proceeding from one side (y direction side) of the reference liquid flow path groove 551 toward the reference liquid flow path groove 551'.

[0296] 72, the angle (acute angle) formed by the direction in which first connecting grooves 554'A and 554'B extend (the direction indicated by the thick dashed arrow in the figure) and the first direction (x direction) is defined as angle θ3. Angle θ3 can be greater than 0° and less than 90°, but is preferably between 30° and 60°.

[0297] Furthermore, each of the second connections 534'D, 554'C extends in a direction inclined relative to the first direction (x direction) so as to proceed from the other side (opposite side in the y direction) of the reference liquid flow path groove 551' toward the reference liquid flow path groove 551'.

[0298] 72, the angle (acute angle) formed by the direction in which the second communication grooves 554'D and 554'C extend (the direction indicated by the thick dashed arrow in the figure) and the first direction (x direction) is defined as angle θ4. The angle θ4 can be in the range of greater than 0° and less than 90°, but is preferably greater than or equal to 30° and less than or equal to 60°.

[0299] The first communication grooves 554'A and 554'B are aligned in the direction in which the first communication grooves extend, and the second communication grooves 554'D and 554'C are aligned in the direction in which the second communication grooves extend.

[0300] For example, as shown in Figure 72, first connecting grooves 554'A and 554'B are arranged in the direction in which the first connecting groove extends, i.e., in the direction in which it forms an angle θ3 with the first direction (x direction) (the direction indicated by the thick dashed arrow in the figure), and second connecting grooves 554'C and 554'D are arranged in the direction in which the second connecting groove extends, i.e., in the direction in which it forms an angle θ4 with the first direction (x direction) (the direction indicated by the thick dashed arrow in the figure).

[0301] This arrangement avoids the need for a complex design for the multiple first and second communication grooves. It is also expected to equalize the functions of each communication groove. For example, it is expected to equalize the ease with which the liquid working fluid can flow from each of the multiple first communication grooves and the multiple second communication grooves into each liquid flow path groove (condensate flow path).

[0302] Furthermore, as described above, the vapor chamber 501' has a plurality of liquid flow path grooves (551', 551'A, 551B) and a plurality of convex portion rows (553'A, 553'B, 555'C, 553'D) extending in the first direction with these liquid flow path grooves interposed therebetween, so that the concave-convex structure of the inner liquid flow path section 538' of the vapor chamber 501' can be made more complex, thereby increasing the surface area of ​​the inner liquid flow path section 538'. This can further increase the amount of working fluid transported by capillary action, thereby further improving transport efficiency.

[0303] Furthermore, the first communication groove 554'A and the second communication groove 554'C of the vapor chamber 501' have a configuration that extends in a direction inclined with respect to the first direction. Therefore, similar to the vapor chamber 501 of the above-described configuration 6a, it is expected that the vapor working fluid that passes through the vapor flow path 4 and diffuses in the direction opposite to the first direction (x direction) will not easily infiltrate into the liquid flow path groove (condensate flow path) through the first communication groove 554'A and the second communication groove 554'C, which are generally opposite to the diffusion direction.

[0304] 6.3.Form 6c Next, the vapor chamber according to the embodiment 6c will be described with reference to FIG.

[0305] As described above, the first communication groove 554'A and the second communication groove 554'C of the vapor chamber 501' according to form 6b extend in a direction inclined with respect to the first direction. Therefore, similar to the vapor chamber 501 according to form 6a, it is expected that the vapor working fluid diffusing in the direction opposite to the first direction (x direction) through the vapor flow path portion will be less likely to infiltrate the liquid flow path groove through the first communication groove 554'A and the second communication groove 554'C, which are generally opposite to the diffusion direction.

[0306] However, in the vapor chamber 501' described above, unlike the vapor chamber 501 according to Configuration 6a, the distance (D3) between adjacent liquid flow path convex portions is constant (see FIG. 72). That is, in the vapor chamber 501' shown in FIG. 72, the distance between the first liquid flow path convex portion and the second liquid flow path convex portion that constitute a pair of liquid flow path convex portions is not shorter on the first direction side than on the opposite side from the first direction side, as in the vapor chamber 501 according to Configuration 6a.

[0307] More specifically, in the vapor chamber 501 according to form 6a, as shown in FIG. 69, the distance between the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B was such that the distance (D1) on the first direction side (x-direction side) was smaller than the distance (D2) on the opposite side from the first direction side.

[0308] And, because of this configuration, the liquid working fluid that has passed through the end on the side where the distance between first liquid flow path convex portion 552A and second liquid flow path convex portion 552B is shorter will diffuse in the region sandwiched between the next pair of liquid flow path convex portions 552. And, due to the pressure of this diffusion and the volume of liquid working fluid present in the region sandwiched between the pair of liquid flow path convex portions 552, it is expected that the working fluid in vapor form can be more effectively prevented from invading the liquid flow path portion 551 (condensate flow path 3) from the first communication groove 554A and the second communication groove 554B.

[0309] On the other hand, in the vapor chamber 501' according to form 6b, as shown in FIG. 72, the distance (D3) between adjacent liquid flow path convex portions 552'B and 552'D is constant, and the distance on the first direction side (x direction side) and the distance on the opposite side to the first direction side are also the same.

[0310] Therefore, in terms of the effect of the vapor chamber 501 of form 6a, namely, the effect of more effectively preventing the vapor working fluid from invading the reference liquid flow path groove 551' (condensate flow path 3) from the first connecting groove 554'B and the second connecting groove 554'D, the vapor chamber 501 is preferable.

[0311] Furthermore, in the vapor chamber 501' shown in Figure 72, each of the first connecting grooves 554'A, 554'B is aligned in the direction in which the first connecting groove extends, and each of the second connecting grooves 554'D, 554'C is aligned in the direction in which the second connecting groove extends.

[0312] For example, as shown in Figure 72, first connecting grooves 554'A and 554'B are arranged in the direction in which the first connecting groove extends, i.e., in the direction in which it forms an angle θ3 with the first direction (x direction) (the direction indicated by the thick dashed arrow in the figure), and second connecting grooves 554'C and 554'D are arranged in the direction in which the second connecting groove extends, i.e., in the direction in which it forms an angle θ4 with the first direction (x direction) (the direction indicated by the thick dashed arrow in the figure).

[0313] Therefore, the vapor working fluid that infiltrates through first communication groove 554'A, which is located further outward from reference liquid flow path groove 551', may pass through first communication groove 554'B, which is located further inward, and easily infiltrate into reference liquid flow path groove 551' (condensate flow path 3), because there is no liquid flow path convex portion in the direction of extension of this first communication groove. Similarly, the vapor working fluid that infiltrates through second communication groove 554'C, which is located further outward from reference liquid flow path groove 551', may pass through second communication groove 554'D, which is located further inward, and easily infiltrate into reference liquid flow path groove 551' (condensate flow path 3), because there is no liquid flow path convex portion in the direction of extension of this second communication groove.

[0314] Therefore, in the vapor chamber according to form 6c, a liquid flow path convex portion is present in the direction of extension of the communication groove. Note that the vapor chamber according to form 6c differs from the vapor chambers according to forms 6a and 6b in the shape of its inner liquid flow path portion, but the other configurations can be the same as those of the vapor chamber according to form 6a.

[0315] FIG. 73 is a diagram showing an example of an inner liquid flow path section 538" of a vapor chamber 501" according to embodiment 6c. As shown in FIG. 73, the inner liquid flow path section 538" of the vapor chamber 501" has three liquid flow path grooves (551", 551"A, 551"B) including a reference liquid flow path groove 551". Each liquid flow path groove extends in the first direction (x direction).

[0316] Furthermore, the internal liquid flow path section 538" of the vapor chamber 501" has four convex portion rows (553"A, 553"B, 553"C, 553"D) extending in the first direction. Of the four convex portion rows (553"A, 553"B, 553"C, 553"D), the convex portion row on one side (the y-direction side) of the reference liquid flow path groove 551" is the first convex portion row (553"A, 553"B), and the convex portion row on the other side (the opposite side to the y-direction) of the reference liquid flow path groove 551" is the second convex portion row (553"D, 553"C).

[0317] To put it more simply, in the example shown in Figure 73, the following are arranged in order from the y-direction side: first convex portion row 553''A, liquid flow path groove 551''A, first convex portion row 553''B, reference liquid flow path groove 551'', second convex portion row 553''D, liquid flow path groove 551''B, and second convex portion row 553''C.

[0318] The first convex portion row 553"A includes a plurality of liquid flow path convex portions 552"A arranged in a first direction (x direction) via a plurality of first communication grooves 554"A. Similarly, the first convex portion row 553"B includes a plurality of liquid flow path convex portions 552"B arranged in the first direction via a plurality of first communication grooves 554"B. Furthermore, the second convex portion row 553"D includes a plurality of liquid flow path convex portions 552"D arranged in the first direction via a plurality of second communication grooves 554"D. Furthermore, the second convex portion row 553"C includes a plurality of liquid flow path convex portions 552"C arranged in the first direction via a plurality of second communication grooves 554"C.

[0319] Each of the first communication grooves 554"A, 554"B extends in a direction inclined with respect to the first direction (x direction) so as to proceed in the first direction (x direction) while proceeding from one side (y direction side) of the reference liquid flow path groove 551" toward the reference liquid flow path groove 551". In the example shown in Figure 73, the angle (acute angle) formed between the extension direction of the first communication groove 554"A (the direction indicated by the thick dashed arrow in the figure) and the first direction (x direction) is defined as angle θ5. The angle θ5 can be in the range of greater than 0° and less than 90°, but is preferably greater than or equal to 30° and less than 60°.

[0320] Furthermore, each of the second communication grooves 554"D, 554"C extends in a direction inclined with respect to the first direction (x direction) so as to proceed in the first direction (x direction) while proceeding from the other side (the opposite side in the y direction) of the reference liquid flow path groove 551" toward the reference liquid flow path groove 551". In the example shown in Figure 73, the angle (acute angle) formed by the extension direction of the second communication groove 554"C (the direction indicated by the thick dashed arrow in the figure) and the first direction (x direction) is defined as angle θ6. The angle θ6 can be in the range of greater than 0° and less than 90°, but is preferably greater than or equal to 30° and less than 60°.

[0321] Here, in the vapor chamber of this embodiment, in a pair of adjacent first convex rows, the first convex row arranged on the outside of the reference liquid flow path groove is referred to as the outer first convex row, and the first convex row arranged on the inside of the reference liquid flow path groove is referred to as the inner first convex row, and in a pair of adjacent second convex rows, the second convex row arranged on the outside of the reference liquid flow path groove is referred to as the outer second convex row, and the second convex row arranged on the inside of the reference liquid flow path groove is referred to as the inner second convex row, then the liquid flow path convex parts that make up the inner first convex row are arranged in the direction in which the first connecting grooves that pass between the liquid flow path convex parts that make up the outer first convex row extend, and the liquid flow path convex parts that make up the inner second convex row are arranged in the direction in which the second connecting grooves that pass between the liquid flow path convex parts that make up the outer second convex row extend.

[0322] For example, in the vapor chamber 501'' shown in Figure 73, the first convex portion row 553''A is the outer first convex portion row, and the first convex portion row 553''B is the inner first convex portion row. Similarly, the second convex portion row 553''C is the outer second convex portion row, and the second convex portion row 553''D is the inner second convex portion row.

[0323] Furthermore, in the direction in which the first connecting groove 554''A extends, which passes between the liquid flow path convex portions 552''A constituting the first convex portion row 553''A, which is the outer first convex portion row, the liquid flow path convex portions 552''B constituting the first convex portion row 553''B, which is the inner first convex portion row, are arranged (the direction indicated by the thick dashed arrow in the figure).

[0324] Therefore, the flow of the working fluid in the form of steam that has entered through first communication groove 554"A, which is located further outward from reference liquid flow path groove 551", is blocked by liquid flow path protrusion 552"B, which exists in the direction in which this first communication groove extends, making it less likely to enter reference liquid flow path groove 551", which is located further inward. In addition, the flow of steam is dispersed by liquid flow path protrusion 552"B, which reduces the pressure of the steam. Therefore, it becomes even more difficult for the working fluid to enter reference liquid flow path groove 551".

[0325] Similarly, in the direction in which the second connecting groove 554''C extends, which passes between the liquid flow path convex portions 552''C that constitute the second convex portion row 553''C, which is the outer second convex portion row, the liquid flow path convex portion 552''D that constitutes the second convex portion row 553''D, which is the inner second convex portion row, is arranged (the direction indicated by the thick dashed arrow in the figure).

[0326] Therefore, the flow of the working fluid in the form of steam that has entered through the second communication groove 554"C, which is located further outward from the reference liquid flow path groove 551", is blocked by the liquid flow path protrusion 552"D that exists in the direction in which this first communication groove extends, making it less likely to enter the reference liquid flow path groove 551", which is located further inward. In addition, the liquid flow path protrusion 552"D disperses the flow of steam, reducing the pressure of the steam. Therefore, it becomes even more difficult for the working fluid to enter the reference liquid flow path groove 551".

[0327] Therefore, the vapor chamber 501" effectively prevents the vapor working fluid from entering the reference liquid flow path groove 551", improving the transport function of the liquid working fluid and improving heat transport efficiency.

[0328] Furthermore, similar to the vapor chamber 501' shown in Figure 72, the vapor chamber 501'' has multiple liquid flow path grooves (551'', 551''A, 551''B) and multiple rows of convex portions (553''A, 553''B, 553''C, 553''D) extending in the first direction with these liquid flow path grooves interposed therebetween, making it possible to make the uneven structure of the inner liquid flow path section 538'' of the vapor chamber 501'' more complex and to increase the surface area of ​​the inner liquid flow path section 538''.As a result, the amount of working fluid transported by capillary action can be increased, and the transport efficiency can be further improved.

[0329] The above-described embodiments of the present disclosure are not limited to the above embodiments, and the components can be modified and embodied without departing from the spirit of the present disclosure. Furthermore, the components disclosed in the above embodiments can be combined to create various embodiments that produce the desired effects. Some of the components shown in each embodiment may be deleted, or only one or some of the components may be used in order to obtain the required effect. [Explanation of symbols]

[0330] 1, 51 Vapor chamber 2 Closed space 3 Condensate flow path 4 Steam flow path 10 First Sheet 11 Main unit 12 Injection part 20 Second Sheet 21 Main Unit 22 Injection part 30, 52 Third seat 31, 53 Main unit 32 Injection part 33 Peripheral joint 34 Peripheral liquid flow path section (liquid flow path section) 37 Introduction 38, 54 Inner liquid flow path section (liquid flow path section) 41 Introduction 42 Steam flow channel 44 Steam flow path connecting groove 54a Thickness direction through hole 80 Electronic equipment 81 Case 83 Electronic Components 101 Vapor Chamber 130 Third Sheet 131 Main Unit 134 Peripheral liquid flow path section (liquid flow path section) 136 Insulation groove 138 Inner liquid flow path section (liquid flow path section) 140 Groove for insulation 201 Vapor Chamber 230 Third seat 238 Inner liquid flow path section (liquid flow path section) 241 Introduction 301 Vapor Chamber 310 First Sheet 311 Inner seat 312 Reinforcement sheet 320 Second Sheet 321 Inner seat 322 Reinforcement Sheet 401 Vapor Chamber 410 First Sheet 411 Inner seat 413 Barrier Sheet 420 Second Sheet 423 Barrier Sheet 501 Vapor Chamber 538 Inner liquid flow path section 551 Steam flow groove 552 Pair of liquid flow path convex parts 552A First liquid flow path convex part 552B Second liquid flow path convex part 553A First liquid flow path convex part row 553B Second liquid flow path convex portion row 554A First connecting groove 554B Second connecting trench

Claims

[Claim 1] A sheet for a vapor chamber in which a working fluid is sealed in a sealed space, the sheet for the vapor chamber has a first surface and a second surface opposite the first surface; The sheet has a second flow path provided on the first surface and a first flow path provided through the sheet from the first surface to the second surface, the second flow path communicates with the first flow path through a wall surface of the first flow path by a plurality of communication openings; the wall surface has a peak portion that protrudes most toward the inside of the first flow path, The wall surface is inclined from the top portion toward the first surface in a cross-sectional view. Sheet for vapor chamber.

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