Vapor chamber, sheet for vapor chamber, and electronic apparatus

Abstract

To provide a vapor chamber that can increase heat transport capacity.SOLUTION: A vapor chamber includes a sealed space in which a working fluid is encapsulated. The sealed space includes: a first flow passage and a liquid flow passage part adjacent to the first flow passage.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

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

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

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

[0005] More specifically, a vapor flow path and a condensate flow path are provided inside the vapor chamber, and a 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 through 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 the heat source being cooled. 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 its phase to a liquid state. The liquid working fluid that has changed phase passes through the condensate flow path, returns to the position of the heat source, receives heat from the heat source again, and evaporates, changing to a gaseous state. By circulating as described above, the heat generated from the heat source 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] JP 2007-212028 A Summary of the Invention [Problem to be solved by the invention]

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

[0008] One embodiment of the present disclosure is a vapor chamber in which a working fluid is sealed in an enclosed space, the vapor chamber being made of three stacked sheets, of which the central sheet is provided with a first flow path penetrating the sheet in the thickness direction and extending along the sheet surface, and a liquid flow path section adjacent to the first flow path and having a second flow path, the second flow path being provided as a groove on each of one side and the other side in the thickness direction of the liquid flow path section, and the first flow path and the second flow path being connected by a communication opening provided on each of the one side and the other side in the thickness direction of the liquid flow path section. Effect of the Invention

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

[0010] [Figure 1] FIG. 1 is a perspective view of the vapor chamber 1. [Diagram 2] FIG. 2 is an exploded perspective view of the vapor chamber 1. FIG. [Diagram 3] FIG. 3 is a view of the third sheet 30 seen from the z direction. [Figure 4] FIG. 4 is a view seen from the opposite side to FIG. [Diagram 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 circumferential liquid flow path portion 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 for explaining another example of the outer peripheral liquid flow path portion. [Figure 11] FIG. 11 is a diagram for explaining another example of the outer peripheral liquid flow path portion. [Figure 12] FIG. 12 is a diagram for explaining 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 portion 38. FIG. [Figure 14] FIG. 14 is a partially enlarged view 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. 13 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. [Diagram 23] FIG. 23 is a diagram illustrating the sealed space of the vapor chamber 51. As shown in FIG. [Figure 24] FIG. 24 is a cross-sectional view of the vapor chamber 51. [Diagram 25] FIG. 25 is an enlarged view of a portion 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 viewed from the z direction. [Figure 29] FIG. 29 is a view seen from the opposite side to FIG. [Diagram 30] FIG. 30 is a cross-sectional view of the third sheet 130. [Diagram 31] FIG. 31 is another cross-sectional view of the third sheet 130. As shown in FIG. [Diagram 32] FIG. 32 is a cross-sectional view focusing on the outer circumferential liquid flow path portion 134. [Diagram 33] FIG. 33 is a diagram illustrating the peripheral liquid flow path section 134. As shown in FIG. [Diagram 34] FIG. 34 is a cross-sectional view of the area where the pillar 136a is disposed. [Diagram 35] FIG. 35 is a cross-sectional view focusing on the inner liquid flow path portion 138. [Diagram 36] FIG. 36 is a diagram illustrating the inner liquid flow path section 138. As shown in FIG. [Figure 37] FIG. 37 is a cross-sectional view of a portion where the pillar 140a is disposed. [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. [Diagram 40]FIG. 40 is an enlarged view of a portion of FIG. [Diagram 41] FIG. 41 is an enlarged cross-sectional view of the area where the pillar 136a is disposed. [Diagram 42] FIG. 42 is an enlarged view of a portion of FIG. [Diagram 43] FIG. 43 is an enlarged cross-sectional view of a portion where the pillar 140a is disposed. [Diagram 44] FIG. 44 is a diagram for explaining another embodiment. [Diagram 45] FIG. 45 is a diagram for explaining another embodiment. [Figure 46] FIG. 46 is a diagram for explaining another embodiment. [Figure 47] FIG. 47 is a diagram for explaining 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 for explaining 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 for explaining the manufacturing process of the vapor chamber 301. [Figure 60] FIG. 60 is a diagram for explaining the manufacturing process of the vapor chamber 301. [Figure 61] FIG. 61 is a diagram for explaining the manufacturing process of the vapor chamber 301. [Figure 62] FIG. 62 is a diagram for explaining the manufacturing process of the vapor chamber 301. [Figure 63] FIG. 63 is a diagram for explaining the manufacturing process of the vapor chamber 301. [Figure 64] FIG. 64 is a diagram for explaining 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 for explaining the inner liquid flow path portion 538 in the vapor chamber 501. As shown in FIG. [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 for explaining an inner liquid flow path portion 538' in a 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 PREFERRED EMBODIMENTS

[0011] The present disclosure will be described below based on the embodiments shown in the drawings. In the drawings shown below, the size and ratio of the components may be changed or exaggerated for ease of understanding. In addition, for ease of viewing, the illustration of parts that are not necessary for the explanation and repeated reference symbols may be omitted. In addition, terms such as "parallel," "orthogonal," and "same," which specify the shape, geometric conditions, and physical characteristics and their degree, as well as the length, angle, and physical characteristic values ​​used in this specification, are to be interpreted without being bound by strict meanings, but including the range in which similar functions can be expected. Furthermore, in the drawings, the shapes of multiple parts that can be expected to have similar functions are regularly depicted for clarity, but the shapes of the parts may be different from each other within the range in which the functions can be expected without being bound by strict meanings. In addition, in the drawings, the boundary lines indicating the joint surfaces between members are shown as simple straight lines for convenience, but the shape of the boundary line is not limited to being a strict straight line, and is arbitrary within the range in which the desired joint 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 the embodiment 1a, and Fig. 2 shows an exploded perspective view of the vapor chamber 1. For convenience, these figures and each of the figures shown below also show arrows (x, y, z) indicating directions corresponding to a three-dimensional orthogonal coordinate system as necessary. 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 "middle sheet 30"). As will be described later, these sheets are stacked and joined (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, for example, Figure 15), 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 and the other surfaces in the thickness direction, the inner surface 10a and the outer surface 10b). The first sheet 10 is composed of flat surfaces on both sides, 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 has a body 11 and an injection portion 12 . The main body 11 is a sheet-like portion that forms a hollow portion and a sealed space, and in this embodiment, is a rectangle with arcuate corners (so-called R-shaped) in a plan view. However, the main body 11 of the first sheet 10 may have a shape other than the rectangular shape of this embodiment as required for the vapor chamber. For example, it may have a circular shape, an elliptical shape, a triangular shape, or another polygonal shape, as well as a shape having 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 sheet that is quadrangular in plan view and 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, may be 0.75 mm or less, or may be 0.5 mm or less. On the other hand, the thickness is preferably 0.01 mm or more, may be 0.05 mm or more, or may be 0.1 mm or more. The thickness range may be determined by a combination of any one of the multiple upper limit candidate values ​​and any one of the multiple lower limit candidate values. The thickness range may also be determined by a combination of any two of the multiple upper limit candidate values, or a combination of any two of the multiple lower limit candidate values. This makes it possible to increase the number of situations in which the thin vapor chamber can be used.

[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, it does not necessarily have to be a metal material, and examples of such materials include AlN, Si 3 N 4 , or Al 2 O 3 Ceramics such as these and resins such as polyimide and epoxy are also possible. Furthermore, a sheet having two or more types of materials laminated therein may be used, and 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 having 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 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 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 having different strengths are laminated may be used.

[0022] <Third sheet> In this embodiment, the third sheet 30 is a sheet that is sandwiched and overlapped 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 to be superimposed on the first sheet 10, and Fig. 4 shows the surface that is to be superimposed on the second sheet 20. Also, in Fig. 5, C in Fig. 3 is 1 -C 1 6 is a cross-sectional view taken along the line indicated by C in FIG. 2 -C 2 The cross-sectional views taken along the lines indicated by are shown in the figures. In the cross-sectional views, the parts related to the cut surfaces are hatched (with diagonal lines), and the parts not related to the cut surfaces that appear in the cross-sectional views but that need to be shown 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 that spans 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 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 (having a so-called R) in a plan view. However, the main body 31 may be rectangular as in this embodiment, or may be any other shape required for a vapor chamber. For example, it may be circular, elliptical, triangular, or other polygonal, or may be L-shaped, T-shaped, crank-shaped, U-shaped, or other shapes having a bent portion. It may also be a shape that combines at least two of these shapes.

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

[0027] The thickness of the third sheet 30 may be 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 the first sheet 10 and the second sheet 20. This allows the cross section of the steam flow passage 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 joint 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 the vapor of the working fluid passes, and a condensate flow path 3 (see FIG. 18, etc.) which is a second flow path through which the condensate 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 FIG. 13(a), FIG. 13(b), etc.) provided in the inner liquid flow path portion 38 form the condensate flow path 3.

[0030] <<Perimeter joint>> The outer periphery joining portion 33 is a portion provided along the outer periphery of the main body 31, and includes an outer periphery joining surface 33a provided on the first surface 30a and an outer periphery joining surface 33b provided on the second surface 30b of the main body 31. The outer periphery joining surface 33a overlaps the outer periphery of the inner surface 10a of the first sheet 10, and the outer periphery 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 portion 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 portion to form an enclosed space.

[0031] 3 to 7. 1 The width (size in a direction perpendicular to the direction in which the outer peripheral joining portion 33 extends) of the outer peripheral joining portion 33 (the outer peripheral joining surface 33a and the outer peripheral joining surface 33b) shown in can be appropriately set as necessary. 1 The width W is preferably 3.0 mm or less, may be 2.5 mm or less, or may be 2.0 mm or less. 1 If the width W is greater than 3.0 mm, the internal volume of the sealed space will be small, and there is a risk that the steam flow path and the condensate flow path will not be sufficiently secured. 1 The width W is preferably 0.1 mm or more, may be 0.4 mm or more, or may be 0.8 mm or more. 1 If the width W is less than 0.1 mm, there is a risk that the joining area will be insufficient if the sheets are misaligned during joining. 1The 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. 1 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. In this embodiment, the width of the outer peripheral bonding surface 33a and the width of the outer peripheral bonding surface 33b are both W 1 However, 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 circumferential liquid flow path portion 34 functions as a liquid flow path portion and is a portion that constitutes a part of the condensed liquid flow path 3, which is a second flow path through which the working fluid passes when condensed and liquefied. 3 The part indicated by the arrow C in Fig. 7 is shown in Fig. 8 in an enlarged scale. 4 8 is an enlarged plan view (as viewed from the z direction) of the outer peripheral liquid flow path section 34 as viewed from the direction indicated by the arrow A. That is, Fig. 8 shows a part of the outer peripheral liquid flow path section 34 as viewed from the first surface 30a side. Here, Fig. 7(a) is C in Fig. 8 15 -C 15 FIG. 7(b) is a cross-sectional view of 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.

[0033] As can be seen from these figures, the peripheral liquid flow path section 34 is a section formed along the inside of the peripheral joint section 33 of the main body 31 and provided along the outer periphery of the section that becomes the sealed space 2. In addition, liquid flow path grooves 35 (on the first surface 30a side) and liquid flow path grooves 36 (on the second surface 30b side) that are multiple grooves extending along the outer periphery direction 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 liquid flow path grooves 36 are arranged at predetermined intervals in a direction different from the direction in which the liquid flow path grooves 35 and liquid flow path grooves 36 extend. Therefore, as can be seen from Figures 5 to 7, in the cross section of the peripheral liquid flow path section 34, the liquid flow path grooves 35 that are recesses and the convex portions 35a between the liquid flow path grooves 35 are repeatedly formed on the first surface 30a side. Furthermore, on the second surface 30b side, liquid flow path grooves 36 which are recesses and protrusions 36a which are between the liquid flow path grooves 36 are formed in a repeated uneven pattern. That is, in this embodiment, liquid flow path grooves which become the condensed liquid flow paths 3 are provided on both one side and the other side (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, an appropriate size is ensured for the combined overall flow path cross-sectional area of ​​the condensate flow path 3, allowing the required flow rate of condensate to flow, 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 utilizing a large capillary force. The depth and width may be different between one side and the other side (front and back), i.e., between liquid flow channel groove 35 and liquid flow channel groove 36. This allows the flow rate and capillary force to be independently adjusted according to the final product.

[0035] Here, since the liquid flow path grooves 35 and 36 are grooves, they have a bottom in their cross-sectional shape and are open on the opposite side facing the bottom. As will be described later, when the first sheet 10 or the second sheet 20 is superimposed on the third sheet 30, this opening is blocked to form 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 another polygon, or a shape that combines two or more of these.

[0036] Furthermore, in this embodiment, in the outer peripheral liquid flow passage portion 34, as can be seen from Fig. 8, adjacent liquid flow passage grooves 35 communicate with each other at a predetermined interval through communication openings 35b. This promotes equalization of the amount of condensed liquid among the plurality of liquid flow passage grooves 35, enables efficient flow of condensed liquid, and enables smooth return of the working fluid. Note that Fig. 8 shows the first surface 30a side, so the liquid flow passage grooves 35, the convex portion 35a, and the communication openings 35b will be described, but the liquid flow passage grooves 36 and the convex portion 36a provided on the second surface 30b side can be considered in the same way, and are provided with communication openings 36b (not shown), and can be considered in the same way as the liquid flow passage grooves 35, the convex portion 35a, and the communication openings 35b.

[0037] In this embodiment, the communication openings 35b may be arranged at different positions in the extension direction of the liquid flow path groove 35 across one liquid flow path groove 35 as shown in Fig. 8. That is, the protrusions 35a and the communication 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 communication openings 35b may be arranged to face each other at the same position in the extension direction of the liquid flow path groove 35 across one liquid flow path groove 35.

[0038] Other configurations, for example, as shown in Figures 10 to 12, are also possible. Figures 10 to 12 show, from the same viewpoint as Figure 8, one liquid flow path groove 35, two convex portions 35a sandwiching it, and one communication opening portion 35b provided in each convex portion 35a. In all of these cases, the shape of the convex portion 35a from that viewpoint (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 the same as that at other portions and is constant. In contrast, in the protrusion 35a having the shape 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 corner at the end is made arc-shaped and R is formed at the corner, so that the width of the end is smaller, Fig. 11 shows an example in which the end is made semicircular and the width of the end is smaller, and Fig. 12 shows an example in which the end is tapered to be pointed.

[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 portion 37 is provided in the outer peripheral liquid flow path section 34. The introduction portion 37 is a portion formed on the boundary surface with the steam flow path groove 42 and protrudes toward the steam flow path groove 42. In this embodiment, the introduction portion 37 is provided with an apex 37a that protrudes most in the center in the thickness direction (z direction), and an introduction surface 37b that is concave in an arc shape on the outer peripheral liquid flow path section 34 side in cross section is provided from the apex 37a toward the first surface 30a and the second surface 30b side (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. Also, the apex 37a may be a point in cross section, or may have a length.

[0041] With this type of introduction section 37, the above-mentioned shape 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 improving the heat transport capacity.

[0042] The outer peripheral liquid flow path section 34 having the above-mentioned configuration may further have the following configuration. Note that, in order to refer 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 in the same way. 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, and the shapes of the first surface 30a side and the second surface 30b side may be the same or different.

[0043] 3 to 5 and 7(a) show the W 2 The width of the outer peripheral liquid flow passage portion 34 (the size in the direction in which the liquid flow passage grooves 35 and 36 are arranged) shown by W can be appropriately set based on the size of the entire vapor chamber, etc. 2 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. 2 If the width W exceeds 3.0 mm, there is a risk that there will not be enough space for the inner liquid flow path and steam flow path. 2 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. 2 If the width W is less than 0.05 mm, there is a risk that the amount of liquid that flows back to the outside will be insufficient. 2 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. 2 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. In this embodiment, the width of the outer peripheral liquid flow path portion 34 on the first surface 30a side and the width of the outer peripheral liquid flow path portion 34 on the second surface 30b side are both W 2 However, 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] The liquid flow channel 35 is shown in FIG. 3The 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 is preferably 1000 μm or less, may be 500 μm or less, or may be 200 μm or less. 3 The width W is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. 3 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. 3 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 Fig. 7(a), 1 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. 1 The depth D is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. 1 The range of the 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. 1 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. With the above-mentioned configuration, the capillary force of the condensate flow passage, which is necessary for reflux, can be more strongly exerted.

[0045] In order to maximize the capillary force of the condensate flow path, the groove width W 3 to depth D 1 The aspect ratio of the flow channel cross section, expressed as a value obtained by dividing the width by the length, is preferably greater than 1.0. This ratio may be 1.5 or greater, or may be 2.0 or greater. Alternatively, the aspect ratio may be less than 1.0. This ratio may be 0.75 or less, or may be 0.5 or less. Among them, from the viewpoint of manufacturing 3 D 1From this viewpoint, the aspect ratio is preferably greater than 1.3.

[0046] In addition, in Fig. 7(a), 1 The pitch between adjacent liquid flow path grooves 35 among the plurality of liquid flow path grooves 35 indicated by is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. 1 The pitch P is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. 1 The range of pitch P may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. 1 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 makes it possible to increase the density of the condensate flow passages while suppressing the condensate flow passages from being crushed due to deformation during joining or assembly.

[0047] The communication opening 35b is shown in FIG. 1 The size of the opening along the direction in which the liquid flow channel groove 35 extends, indicated by L, is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. 1 The size L is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. 1 The range of the magnitude L may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. 1 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.

[0048] Also, in Figure 8, 2The pitch between adjacent communication openings 35b in the direction in which the liquid flow passage groove 35 extends is preferably 2700 μm or less, may be 1800 μm or less, or may be 900 μm or less. 2 The pitch L is preferably 60 μm or more, may be 110 μm or more, or may be 140 μm or more. 2 The range of pitch L may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. 2 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.

[0049] Regarding the introduction portion 37, W 4 The protrusion amount indicated by (the distance from the end of the protrusion 35a to the apex 37a) is preferably 1000 μm or less, may be 500 μm or less, or may be 300 μm or less. 4 The protrusion amount W is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. 4 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 any one of the plurality of lower limit candidate values. 4 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.

[0050] <<Inner liquid flow path section>> 1 to 5, the inner liquid flow path section 38 will be described. The inner liquid flow path section 38 also functions as a liquid flow path section, and is a part of the condensate flow path 3, which is the second flow path through which the working fluid passes when condensed and liquefied, and a part that constitutes the introduction section 41. 5 13(a) and 13(b) also show the cross-sectional shape of the inner liquid flow path portion 38. Also, FIG. 14 shows the portion indicated by the arrow C in FIG. 61 shows an enlarged plan view of the inner liquid flow path section 38 as viewed from the direction indicated by the arrow. Here, FIG. 13(a) is C in FIG. 17 -C 17 FIG. 13(b) is a cross-sectional view taken along the arrow C in FIG. 18 -C 18 13(a) is a cross section where the protrusion 39a is disposed on the introduction portion 41 side, and Fig. 13(b) is a cross section where the communication opening 39b is disposed 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. The inner liquid flow path section 38 in this embodiment 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 a plurality of inner liquid flow path sections 38 (three in this embodiment) are arranged at predetermined intervals in a direction parallel to the short side (y direction).

[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 the 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 the like, 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 uneven 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 uneven pattern on the second surface 30b side. That is, in this embodiment, liquid flow path grooves which become the condensed 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 of an appropriate size, allowing the required flow rate of condensate to flow, and by reducing the depth and width of each liquid flow path groove 39 and liquid flow path groove 40 and reducing the flow path cross-sectional area of ​​the condensate flow path 3 (see Figure 18, etc.), which is the second flow path, a large capillary force can be utilized.

[0054] Here, since the liquid flow path grooves 39 and 40 are grooves, they have a bottom in their cross-sectional shape and are open on the opposite side facing the bottom. As will be described later, when the first sheet 10 and the second sheet 20 are overlapped on the third sheet 30, the opening is blocked to form the condensate flow path 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 another polygon, or a shape that combines two or more of these.

[0055] Furthermore, in this embodiment, in the inner liquid flow passage portion 38, adjacent liquid flow passage grooves 39 communicate with each other through communication openings 39b at a predetermined interval, as can be seen from Fig. 14. This promotes equalization of the amount of condensed liquid among the plurality of liquid flow passage grooves 39, enables efficient flow of the condensed liquid, and enables smooth return of the working fluid. Note that Fig. 14 shows the first surface 30a side, so the liquid flow passage grooves 39, the convex portion 39a, and the communication openings 39b will be described, but the liquid flow passage grooves 40 and the convex portion 40a provided on the second surface 30b side can be considered in the same way, and a communication opening 40b (not shown) is provided, and can be considered in the same way as the liquid flow passage grooves 39, the convex portion 39a, and the communication openings 39b. As with the above-described communicating opening 35b, the communicating opening 39b may be arranged 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. The communicating opening 39b and the convex portion 39a may have shapes following the examples shown in Figs. 10 to 12.

[0056] In this embodiment, an introduction part 41 is provided in the inner liquid flow path section 38. The introduction part 41 is a part formed on the boundary surface with the steam flow path groove 42 and is a part that protrudes towards the steam flow path groove 42. In this embodiment, the introduction part 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 on the inner liquid flow path section 38 side in cross section is provided from the apex 41a towards the first surface 30a and the second surface 30b side (z direction). The shape of the introduction part 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 above-mentioned shape makes it easy for condensate to collect on the introduction surface 41b, and the movement of the working fluid between the condensate flow path 3 and the steam flow path 4 through the introduction section 41 is smoother, thereby further improving the heat transport capacity.

[0058] The inner liquid flow path section 38 having the above-mentioned configuration preferably further has the following configuration. Figures 3, 4, 5, and 13(a) show the W 5 The width of the inner liquid flow passage section 38 (the size in the direction in which the inner liquid flow passage section 38 and the steam flow passage groove 42 are arranged, and the largest value) indicated by is preferably 3000 μm or less, and may be 2000 μm or less, or may be 1500 μm or less. On the other hand, this width W 5 The width W is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. 5 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. 5 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.

[0059] In addition, Figs. 3 and 5 show 2The pitch of the multiple inner liquid flow path portions 38 indicated by is preferably 5000 μm or less, may be 3500 μm or less, or may be 3000 μm or less. 2 The pitch P is preferably 200 μm or more, may be 400 μm or more, or may be 800 μm or more. 2 The range of pitch P2 may be determined by combining any one of the multiple upper limit candidate values ​​and any one of the multiple lower limit candidate values. Also, the range of 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 a good balance between the movement of steam and the return of condensate.

[0060] The inner liquid flow path section 38 having the above-mentioned configuration may further have the following configuration. Note that, in order to refer 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 in the same way. 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, and the shapes of the first surface 30a side and the second surface 30b side may be the same or different.

[0061] The liquid flow channel 39 is shown in FIG. 6 The groove width (the size in the direction in which the liquid flow path grooves 39 are arranged, the width at the opening surface of the groove) indicated by is preferably 1000 μm or less, may be 500 μm or less, or may be 200 μm or less. 6 The width W is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. 6 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. 6The 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.

[0062] Also, in Fig. 13(a), 2 The depth of the liquid flow passage groove 39 indicated by D is preferably 200 μm or less, and may be 150 μm or less, or may be 100 μm or less. 2 The depth D is preferably 5 μm or more, may be 10 μm or more, or may be 20 μm or more. 2 The range of the 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. 2 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 makes it possible to exert a strong capillary force in the condensate flow passage, which is necessary for reflux.

[0063] In order to maximize the capillary force of the flow channel, the groove width W 6 to depth D 2 The aspect ratio (horizontal to vertical ratio) of the flow channel cross section, expressed as a value obtained by dividing the vertical to horizontal ratio, is preferably greater than 1.0, may be 1.5 or more, or may be 2.0 or more, or may be less than 1.0, 0.75 or less, or 0.5 or less. Among them, from the viewpoint of manufacturing, the groove width W 6 is depth D 2 From this viewpoint, the aspect ratio is preferably greater than 1.3.

[0064] Also, in Fig. 13(a), 3 The pitch between adjacent liquid flow passage grooves 39 among the plurality of liquid flow passage grooves 39 indicated by is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. 3 The pitch P is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. 3The range of pitch P may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. 3 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 makes it possible to increase the density of the condensate flow passages while suppressing deformation and collapse of the flow passages during bonding or assembly.

[0065] Furthermore, with regard to the communication opening 39b, L 3 The size of the opening along the direction in which the liquid flow passage groove 39 extends, indicated by L, is preferably 1100 μm or less, may be 550 μm or less, or may be 220 μm or less. 3 is preferably 30 μm or more, may be 55 μm or more, or may be 70 μm or more. 3 The range of the magnitude L may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. 3 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.

[0066] Also, in Figure 14, 4 The pitch between adjacent communication openings 39b in the direction in which the liquid flow passage groove 39 extends, indicated by L, is preferably 2700 μm or less, and may be 1800 μm or less, or may be 900 μm or less. 4 The pitch L is preferably 60 μm or more, may be 110 μm or more, or may be 140 μm or more. 4 The range of pitch L may be determined by a combination of any one of the plurality of upper limit candidate values ​​and any one of the plurality of lower limit candidate values. 4 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.

[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 capillary action can be achieved, and the grooves do not have to be parallel to each other.

[0068] Regarding the introduction portion 41, W 7 The protrusion amount indicated by (the distance from the end of the protrusion 39a to the apex 41a) is preferably 1000 μm or less, may be 500 μm or less, or may be 300 μm or less. 7 The protrusion amount W is preferably 20 μm or more, may be 45 μm or more, or may be 60 μm or more. 7 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 any one of the plurality of lower limit candidate values. 7 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.

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

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

[0071] The steam flow passage groove 42 having such a configuration can further have the following configuration. Figures 3, 4, and 5 show 8 The width of the steam flow passage groove 42 (the size in the direction in which the inner liquid flow passage portion 38 and the steam flow passage groove 40 are arranged, and the width at the opening surface of the steam flow passage groove) shown in 3 , and the width W of the liquid flow path groove 39 and the liquid flow path groove 40 6 It is preferably formed larger than 2500 μm, but may be 2000 μm or less, or may be 1500 μm or less. 8 The width W is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. 8 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. 8The range may be determined by combining any two of a plurality of upper limit candidate values, or by combining any two of a plurality of lower limit candidate values. The pitch of the steam flow passage grooves 42 is usually determined by the pitch of the inner liquid flow passage portions 38 . By making the flow passage cross-sectional area of ​​the steam flow passage groove larger than the flow passage cross-sectional area of ​​the liquid flow passage 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 passage groove 42 is a shape based on the introduction portion 37 and the introduction portion 41, but when the 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 any two or more of these. Since the steam flow passage can reduce the flow resistance of the steam to allow the working fluid to return smoothly, the shape of the flow passage cross section can also be determined from this viewpoint.

[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 one in which two or more steam flow path grooves are arranged side by side between adjacent inner liquid flow path sections.

[0074] <<Steam flow passage connection groove>> The steam flow passage communication groove 44 is a groove that communicates the multiple steam flow passage grooves 42. This allows the steam in the multiple steam flow passage grooves 42 to be equalized, and the steam to be transported over a wider area, allowing many condensate flow passages 3 to be used efficiently, making it possible to more smoothly return the working fluid.

[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 in the direction in which the steam flow path groove 42 extends, and the outer circumferential liquid flow path section 34.

[0076] The steam flow passage communication groove 44 is formed so as to communicate with adjacent steam flow passage grooves 42. In this embodiment, as can be seen from Fig. 6, the steam flow passage 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 passage portion 38 and the outer circumferential liquid flow passage portion 33, and holds the inner liquid flow passage portion 38. 3 and 4, in this embodiment, a hole 44d is provided in a connecting portion 44c at a portion of the steam flow passage communication groove 44 where an end portion of groove 32a provided in the injection portion 32 of the third sheet 30 is disposed, and groove 44a communicates with 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 passage communication groove 44 is only required to communicate with a plurality of steam flow passage grooves 42, and its shape is not particularly limited. For example, the steam flow passage communication groove 44 may have the following configuration. Figures 3, 4, and 6 show 9 The width of the steam flow passage communication groove 44 (the size in the direction perpendicular to the communication direction, the width at the opening surface of the groove) is preferably 2500 μm or less, may be 2000 μm or less, or may be 1500 μm or less. 9 The width W is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. 9 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. 9 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.

[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, trapezoidal or other quadrangular, triangular, semicircular, with a semicircular bottom, with a semi-elliptical bottom, or a combination of any two or more of these. The steam flow passage communication grooves can reduce the flow resistance of the steam, thereby enabling the working fluid to return smoothly, and therefore the shape of the flow passage cross section can also be determined from this viewpoint.

[0079] <Vapor chamber structure> Next, a description will be given of the structure when the first sheet 10, the second sheet, and the third sheet 30 are combined to form the vapor chamber 1. This description will provide a further understanding of 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] In Figure 15, C in Figure 1 7 -C 7 FIG. 16 shows a cross-sectional view of the vapor chamber 1 cut in the thickness direction along the y direction indicated by C in FIG. 8 -C 8 1 shows a cross-sectional view of the vapor chamber 1 cut in the thickness direction along the x direction indicated by the arrows. In Fig. 17(a), C in Fig. 15 9 7(a) in the part indicated by , FIG. 17(b) shows a cross section corresponding to FIG. 7(b), and FIG. 18(a) shows a cross section corresponding to FIG. 15 (C). 10 13(a) is shown, and FIG. 18(b) is a cross section corresponding to FIG. 13(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 Figures 8 and 14, the convex portions 35a and 39a have the communication openings 35b and 39b, respectively. Therefore, according to the cross sections in which the communication openings 35b and 39b contact the steam flow path 4 as shown in Figures 17(b) and 18(b), the steam flow path 4 and the steam flow path 3 communicate 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, the main body 31 of the third sheet 30 and the main body 21 of the second sheet 20 overlap, the injection portion 12 of the first sheet 10 of the injection portion 32 of the third sheet 30, and the injection portion 32 of the third sheet 30 and the injection portion 22 of the second sheet 20 overlap.

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

[0083] The third sheet 30 is arranged so that an outer peripheral joining surface 33a provided on the first surface 30a side thereof and an outer peripheral surface of the inner surface 10a of the first sheet 10 overlap, and the third sheet 30 is arranged so that an outer peripheral joining surface 33b provided on the second surface 30b side thereof and an outer peripheral surface of the inner surface 20a of the second sheet 20 overlap, and are joined by a joining means such as diffusion joining 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 disposed 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 and becomes part of the hollow portion. This forms a condensate flow path 3, which is a second flow path through which condensate flows, which is a liquefied state of the working fluid sealed in the hollow portion that has been condensed. Similarly, the second sheet 20 is arranged so that the inner surface 20a of the second sheet 20 overlaps with 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 and becomes part of the hollow portion. This forms a condensate flow path 3, which is a second flow path through which the condensate, which is in a liquefied state due to condensation of the working fluid sealed in the hollow portion, flows.

[0085] The third sheet 30 is disposed 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 and becomes part of the hollow portion. This forms a condensate flow path 3, which is a second flow path through which the condensate, 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 with 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 and becomes part of the hollow portion. This forms a condensate flow path 3, which is a second flow path through which condensate flows, which is a liquefied state of the working fluid sealed in the hollow portion that has been condensed.

[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 assumed to flow, the condensate flow path 3 can obtain a high capillary force compared to a so-called groove flow path in which one side of the flow path is continuously open. Moreover, since the condensate flow passage 3 is formed separately from the steam flow passage 4 which is the first flow passage, it is possible to ensure smooth circulation of the working fluid.

[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 and the other sides of the thickness direction (z direction) of the vapor chamber 1. This allows the flow path cross-sectional area of ​​each condensate flow path 3 to be small (thinner) while the total flow path cross-sectional area of ​​the condensate flow paths 3 to be large, thereby making it possible to maintain a high capillary force and smooth 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 directions (xy directions) but also in the thickness direction (z direction), which is expected to result in more uniform heat transfer and 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 passage groove 42 is blocked by the first sheet 10 and the second sheet 20 to form a part of a hollow portion, which becomes a flow passage for the enclosed working fluid and serves as the steam flow passage 4, which is the first flow passage through which steam flows. Here, it is preferable that the surfaces of the first sheet 10 and the second sheet 20 constituting a part of the steam flow path 4 facing the steam flow path 4 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 the resistance when the steam moves can be reduced.

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

[0091] The shape of the steam flow passage 4 can be considered based on the shape and dimensions described above for the third sheet 30 . In this embodiment, since the introduction part 37 and the introduction part 41 are provided, one steam flow passage 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 in 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 connects the 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 the third sheet 30 is blocked by injection section 22 of the second sheet 20, forming an injection flow path 5 that connects the outside with the hollow portion (condensate flow path 3 and steam flow path 4). However, after the working fluid is injected into the hollow portion from the injection passage 5, the injection passage 5 is closed to form a sealed space 2, so that in the final form of the vapor chamber 1, the hollow portion is not connected to the outside. In this embodiment, the injection part 12, 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 the present invention is not limited to this and may be disposed at any other end, or may be disposed in a plurality of parts. When a plurality of parts are disposed, they may be disposed at each of a pair of ends in the longitudinal direction of the vapor chamber 1, or may be disposed 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 chamber] The vapor chamber as described above can be fabricated, for example, as follows. Liquid flow path grooves 35, 36, 39, 40, steam flow path grooves 42, and grooves 44a and 44b are formed by half-etching a sheet having the outer peripheral shape of third sheet 30. Half-etching refers to etching partway through the sheet without penetrating the sheet in the thickness direction. However, the steam flow path groove 42 is half-etched from both the first surface 30a side and the second surface 30b side so as to penetrate 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 laid on the first surface 30a side of the third sheet 30, and the second sheet 20 is laid on the second surface 30b side of the third sheet 30, and they are temporarily fixed together. The method of temporary fixing is not particularly limited, but examples thereof include resistance welding, ultrasonic welding, and adhesion using an adhesive. After the temporary joining, the first sheet 10, the second sheet 20, and the third sheet 30 are permanently joined together 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 2 to be maintained when the vapor chamber 1 is in operation.

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

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

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

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

[0101] The vapor chamber 1 is installed in the housing of a portable terminal or the like, and is attached to an electronic component 83, which is an object to be cooled, such as a CPU. The electronic component is attached directly to the outer surface or outer surface of the vapor chamber 1, or via a highly thermally conductive adhesive, sheet, tape, or the like. There is no particular limitation on the position in the vapor chamber where the electronic component 83 is attached, and it is appropriately set depending on the relationship with the arrangement of other components in the portable terminal or the like. In this embodiment, as shown by the dotted line in FIG. 1, the electronic component 53 is arranged in the center of the main body 21 in the xy direction on the surface of the second sheet 20 opposite to the side where the third sheet 30 is arranged. Therefore, in FIG. 1, the electronic component 83 is shown by a dotted line because it is in a blind spot and cannot be seen. 20 is a diagram for explaining 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 the condensate present in the sealed space 2 at a position close to the electronic components 83 receives the heat. The condensate absorbs the heat and evaporates. This cools the electronic components 83.

[0103] The evaporated working fluid turns into steam and moves within the steam flow path 4 as shown by the solid straight arrow in Fig. 20. Since this flow occurs in the direction away from the electronic component 83, the steam moves in the direction away from the electronic component 83. The steam in the steam flow path 4 moves away from the electronic component 83, which is the heat source, to the outer periphery of the vapor chamber 1, which is at a relatively low temperature, and is cooled as it moves while heat is absorbed by the first sheet 10, 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, which have absorbed heat from the steam, 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 passage 4 condenses and becomes liquid. This condensed liquid adheres to the wall surface of the steam passage 4. On the other hand, since steam is continuously flowing through the steam passage 4, the condensed liquid adheres to the wall surface of the steam passage 4 as shown by the arrow C in FIG. 11 As shown in FIG. 8 and FIG. 14, the condensate moves to the condensate flow passage 3 as if being pushed by the steam. Since the condensate flow passage 3 in this embodiment is provided with the communication openings 35b, 36b, 39b, and 40b, as shown in FIG. 8 and FIG. 14, the condensate passes through these communication openings and is distributed to the multiple condensate flow passages 3.

[0105] In this embodiment, the condensate flow paths 3 are 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. At this time, if the introduction portion 37 and the introduction portion 41 are provided, there will be a region surrounded by the introduction surface 37b, the introduction 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 allows 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 FIG. 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, according to the vapor chamber 1, the condensate flow passage has a high capillary force, which improves the reflux of the condensate, thereby increasing the amount of heat transport. Furthermore, in this embodiment, the condensate flow paths 3 are provided on both one and the other sides of the vapor chamber 1 in the thickness direction (z direction). This allows the flow path cross-sectional area of ​​each condensate flow path 3 to be small (thinner) while the total flow path cross-sectional area of ​​the condensate flow paths 3 to be large, thereby making it possible to maintain a high capillary force and smooth 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 directions (xy directions) but also in the thickness direction (z direction), which is expected to result in more uniform heat transfer and transport.

[0108] [Number of seats] The vapor chamber 1 described above is an example of a vapor chamber made of three sheets, the first sheet 10, the second sheet 20, and the third sheet 30. By making use of three sheets in this way, the overlapping of the sheets is not complicated compared to the case where more sheets are used, making the manufacturing easier and the bonding of each sheet stronger. Among these, if the first sheet 10 and the second sheet 20 have flat surfaces without being processed as in this embodiment, there is no need to worry about alignment for forming the condensate flow path and the vapor flow path when overlapping the sheets, making the manufacturing easier.

[0109] However, regardless of the number of sheets, it is sufficient that the condensate flow passages 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 inlet surface 41b as shown in Figure 18 compared to when it is constructed with two sheets, and the working fluid is more likely to condense here, resulting in smoother movement of the working fluid. Furthermore, for example, as shown in FIG. 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 shows 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. FIG. 18 corresponds to a view showing an enlarged view of the area (inner liquid flow path section 138) indicated by the arrow.

[0111] The vapor chamber 51 differs from the above-described vapor chamber 1 in that a third sheet 52 is applied instead of the third sheet 30, and the third sheet 52 has a thickness-direction communicating hole 54a in the inner liquid flow path portion 54 of the main body 53. The explanation of the other members and parts is applicable to the vapor chamber 1, so the same reference numerals are used in the drawings and the explanation is omitted. Therefore, the explanation will be given here with attention focused on the thickness-direction communicating hole 54a provided in the inner liquid flow path portion 54.

[0112] The thickness-direction communicating hole 54a is provided in the inner liquid flow path portion 54 of the third sheet 52, and is a hole that communicates from the first surface 30a to the second surface 30b. The thickness-direction communicating hole 54a communicates the liquid flow path groove 39 with the liquid flow path groove 40, and thus the condensate liquid flow path 3 on the first surface 30a side communicates with the condensate liquid flow path 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, and the distribution of the condensate can be made more uniform, allowing the working fluid to flow more smoothly.

[0113] The thickness direction communicating hole 54a is only required to communicate the condensate liquid flow passages 3 arranged on one side and the other side in the thickness direction of one inner liquid flow passage portion 54, and the specific form for this is not particularly limited. For example, it 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 that is a combination of these.

[0115] 24 and 25, the shape of the thickness-direction communicating hole 54a in the extending direction (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 communication 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 side in the thickness direction.

[0117] Although the vapor chamber 1 can exhibit its effect if it is provided with just one thickness-direction communicating hole 54a, it is preferable to provide a plurality of thickness-direction communicating holes 54a in order to obtain a more significant effect.

[0118] The form in which multiple thickness direction communicating holes 54a are provided is not particularly limited, 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 Fig. 23, adjacent thickness direction communicating holes 54a may be shifted in position in the direction perpendicular to the arrangement direction (y direction).

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

[0120] 2. Form 2 2.1.Form 2a [Components] FIG. 26 shows an external perspective view of the vapor chamber 101 according to the embodiment 2a, and FIG. 27 shows an exploded perspective view of the vapor chamber 101. As can be seen from FIG. 26 and FIG. 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 "middle sheet 130"). As will be described later, these sheets are stacked and joined (diffusion bonding, brazing, etc.) 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. The hollow portion is filled with a working fluid to form a sealed space 102 (see FIG. 19, for example), which becomes the vapor chamber 101.

[0121] The first sheet 10 and the second sheet 20 provided in this embodiment can be considered to be the same as the first sheet 10 and the second sheet 20 described in embodiment 1, so they will be given the same reference numerals and will not be described here.

[0122] <Third sheet> In this embodiment, the third sheet 130 is a sheet that is sandwiched and overlapped 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, in Fig. 30, C in Fig. 28 is 101 -C 101 FIG. 31 shows a cross-sectional view taken along the line indicated by C in FIG. 102 -C 102 The cross-sectional views taken 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 overlapping the inner surface 10a of the first sheet 10, a second surface 130b overlapping 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] Moreover, the third sheet 130 includes a main body 131 and an injection section 32. Note that 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 here and the description thereof is 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 corners (so-called R) in plan view. However, the main body 31 may be rectangular as in this embodiment, or may be any other shape required for the vapor chamber. For example, it may be circular, elliptical, triangular, or other polygonal, or may be L-shaped, T-shaped, crank-shaped, U-shaped, or other shapes having a bent portion. It may also be 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 configured to be different.

[0127] A structure for the working fluid to circulate is formed in the main body 131. Specifically, the main body 131 is configured to include an outer periphery joint 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 communication groove 144.

[0128] The vapor chamber 101 of this embodiment includes a first flow path, a steam flow path 4 (see FIG. 38, etc.) through which the vapor of the working fluid passes, and a second flow path, a condensate flow path 3 (see FIG. 42, etc.) through which the condensate liquid obtained by condensing the working fluid passes. The steam flow path groove 142 of the third sheet 130 forms the steam flow path 4, and the liquid flow path groove 35 provided in the outer circumferential 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 similar to the outer peripheral joint 33 described in the above-mentioned embodiment 1, so the same reference numerals are used here and the description is omitted.

[0130] <<Peripheral liquid flow path section>> The outer circumferential liquid flow path portion 134 functions as a liquid flow path portion, 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 is provided with a portion which constitutes the heat insulating portion 6. 103 The part indicated by the arrow C in FIG. 32 is shown in enlarged form in FIG. 33. 105 33 is an enlarged view of the outer peripheral liquid flow path section 134 as viewed from the direction indicated by the arrow Z. That is, Fig. 33 shows a part of the outer peripheral liquid flow path section 134 as viewed from the second surface 130b.

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

[0132] A plurality of liquid flow path grooves 35 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 plurality of 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 explained in the above-mentioned embodiment 1, so the same reference numerals are used here and the explanation is omitted.

[0133] As can be seen from FIGS. 29 to 33, in this embodiment, the outer circumferential liquid flow path portion 134 is provided with a groove 136 for a heat insulating portion on the second surface 30b side. The groove for the insulation section 136 is a groove that extends along the direction in which the outer peripheral liquid flow path section 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 groove for the insulation section 136.

[0134] Here, since the groove 136 for the heat insulating portion is a groove, the cross-sectional shape thereof has a bottom and an opening on the opposite side (second surface 130b) facing the bottom. As described later, when the second sheet 20 is superimposed on the third sheet 30, the 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 rectangle, a square, a trapezoid, or other polygon, or a combination of any two or more of these.

[0135] In addition, FIG. 34 shows the C 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 insulation groove 136 where the pillars 136a are not provided. As can be seen from these figures, multiple pillars 136a standing upright from the bottom are arranged at intervals within the groove for heat insulation 136. 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 a rectangle as in this embodiment, a polygon such as a triangle or pentagon, a circle, an ellipse, or any other shape can be applied.

[0137] In addition, the pitch and number of the columns are not particularly limited and can be set appropriately. Therefore, the number of columns may be one or fewer, and one column may be configured to extend long along the groove for the heat insulation portion.

[0138] In this embodiment, as shown in Fig. 30, an introduction section 37 is provided in the outer peripheral liquid flow path section 134. The introduction section 37 can be considered to be similar to 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-mentioned configuration may further have the following configuration.

[0140] 28 to 30 and 32. 102 The width of the outer peripheral liquid flow passage portion 134 (the size in the direction in which the liquid flow passage 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 inner liquid flow path and steam 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 that flows back to the outside will be insufficient. 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. In this embodiment, the width of the outer peripheral liquid flow path section 134 on the first surface 130a side and the width of the outer peripheral liquid flow path section 134 on the second surface 130b side are both W 102 However, 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.

[0141] Regarding the groove for the heat insulating part 136, 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 the 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. 107 FIG 35 also shows the cross-sectional shapes of the inner liquid flow path portion 38, the heat insulating groove 140, and the introduction portion 41. FIG 36 also shows the cross-sectional shapes of the inner liquid flow path portion 38, the heat insulating groove 140, and the introduction portion 41. 109 1 shows an enlarged plan view of the inner liquid flow path section 138 as viewed 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. The inner liquid flow path section 138 in this embodiment extends in a direction (x direction) parallel to the long side of the rectangle in a plan view (when viewed from the z direction) of the main body 131, and a plurality of inner liquid flow path sections 138 (three in this embodiment) are arranged at predetermined intervals in a direction parallel to the short side (y direction).

[0144] A first surface 130a of the inner liquid flow path section 138 is formed with liquid flow path grooves 39 which are multiple grooves extending along the direction in which the inner liquid flow path section 138 extends, and the multiple liquid flow path grooves 39 are arranged at predetermined intervals in a direction different from the extension direction. Here, the liquid flow path grooves 39 can be considered to be similar to the liquid flow path grooves 39 described in the first embodiment, so the same reference numerals are used and the description thereof is 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 for the insulation section 140 is a groove that extends along the extension direction of the inner liquid flow path section 138, 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 for the insulation section 140.

[0146] Here, since the groove 140 for the heat insulating portion is a groove, the cross-sectional shape thereof has a bottom and an opening on the opposite side (second surface 130b) facing the bottom. As described later, the 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 rectangle, a square, a trapezoid, or other polygon, or a combination of any two or more of these.

[0147] In addition, FIG. 37 shows the C 110 -C 11037 is a cross-sectional view taken along the line 37a-37c 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 provided. 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 part 140. These pillars 140a prevent the groove for heat insulation part 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 (the shape from the viewpoint of Figure 36) is not particularly limited, and in addition to a rectangle as in this embodiment, a polygon such as a triangle or pentagon, a circle, an ellipse, or any other shape can be applied.

[0149] In addition, the pitch and number of the columns are not particularly limited and can be set appropriately. Therefore, the number of columns may be limited to one or a small number, and one column may be configured to extend long along the heat insulation 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 similar to the introduction section 41 described in embodiment 1, and therefore the same reference numerals will be used and a description thereof will be omitted.

[0151] The inner liquid flow path section 138 having the above-mentioned configuration preferably further has the following configuration. 28 to 30 and 35. 106 The width of the inner liquid flow passage section 138 (the size in the direction in which the inner liquid flow passage section 138 and the steam flow passage groove 42 are arranged, and the largest value) is preferably 3000 μm or less, and may be 2000 μm or less, or may be 1500 μm or less. On the other hand, this width W 106 The width W is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. 106The 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 multiple inner liquid flow path sections 138 shown in 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 any 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 a good balance between the movement of steam and the return of condensate.

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

[0154] Regarding the groove for the heat insulating part 140, 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. 108 The 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 the 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 the vaporized steam generated when the working fluid evaporates passes, and constitutes a 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 a 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 passage groove 142 is formed as a groove (slit) formed inside the ring of the outer peripheral liquid flow passage section 134 of the main body 131. More specifically, the steam flow passage groove 142 in this embodiment is formed between adjacent inner liquid flow passage sections 138 and between the outer peripheral liquid flow passage section 134 and the inner liquid flow passage section 138, and is a groove that is rectangular in plan view of the main body 131 and extends in a direction parallel to the long side (x direction). A plurality of steam flow passage grooves 142 (four in this embodiment) are arranged in a direction parallel to the short side (y direction). The steam flow passage groove 142 in this embodiment is configured to communicate with the first surface 130a and the second surface 130b of the third sheet 130, that is, it is a slit-shaped groove that opens 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 portion 134, the inner liquid flow path portion 138, and the steam flow path grooves 142 are alternately repeated in the y direction.

[0157] The configuration of the steam flow passage groove 142 having such a configuration can be considered to be similar to the steam flow passage groove 42 described in the first embodiment.

[0158] <<Steam flow passage connection 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, a description will be given of the structure when the first sheet 10, the second sheet, and the third sheet 130 are combined to form the vapor chamber 101. This description will provide a better understanding of the shape of the vapor chamber 101, as well as the arrangement, size, shape, and the like of each component that the first sheet 10, the second sheet, and the third sheet 130 should have.

[0160] In Figure 38, C in Figure 26 111 -C 111 FIG. 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 the arrows. Figure 40 shows C in Figure 38. 113 41 shows a portion of the outer peripheral liquid flow path section 134 where the pillars 136a are provided, and FIG. 42 shows a portion of the outer peripheral liquid flow path section 134 where the pillars 136a are provided. 114 42 and 43 show enlarged views 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 have 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 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, the main body 131 of the third sheet 130 and the main body 21 of the second sheet 20 overlap, the injection portion 12 of the first sheet 10 of the injection portion 32 of the third sheet 130, and the injection portion 32 of the third sheet 130 and the injection portion 22 of the second sheet 20 overlap.

[0162] By stacking the first sheet 10, the second sheet 20 and the third sheet 130, the components of the main body 11, the main body 21 and the main body 131 are arranged as shown in Figures 38 to 42. Specifically, the components are 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 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 an outer peripheral joining surface 33b provided on the second surface 30b side thereof and the outer peripheral surface of the inner surface 20a of the second sheet 20 overlap, and are joined by a joining means such as diffusion joining or brazing. As a result, a hollow portion 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 portion to form a sealed space 102.

[0164] The third sheet 130 is disposed 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 and becomes part of the hollow portion. This forms a condensate flow path 3, which is a second flow path through which the condensate, which is in a liquefied state due to condensation of the working fluid sealed in the hollow portion, flows.

[0165] The second sheet 20 is disposed 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 groove 136 for the insulation portion is blocked by the second sheet 20 to form the insulation portion 6. The insulation portion 6 is configured not to communicate with the condensate flow path 3 and the steam flow path 4, and is configured to have a lower thermal conductivity than the material adjacent to the insulation portion 6. There is no particular limitation to the specific configuration, but the insulation 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 disposed 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 the condensate, which is in a liquefied state due to condensation of the working fluid sealed in the hollow portion, flows.

[0167] The second sheet 20 is disposed 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 groove 140 for the insulation portion is blocked by the second sheet 20 to form the insulation portion 6. The insulation portion 6 is configured not to communicate with the condensate flow path 3 and the steam flow path 4, and is configured to have a lower thermal conductivity than the material adjacent to the insulation portion 6. There is no particular limitation to the specific configuration, and the insulation portion 6 may be evacuated, filled with air or other gas, or filled with a material having low thermal conductivity.

[0168] In this way, in the condensate flow path 3, a thin flow path surrounded by walls on all four sides in cross section is formed, so that the condensate moves by strong capillary force and smooth circulation is possible. That is, when considering a flow path through which the condensate is assumed to flow, the condensate flow path 3 can obtain a high capillary force compared to a flow path based on a so-called groove in which one side of the flow path is continuously open. Moreover, since the condensate flow passage 3 is formed separately from the steam flow passage 4 which is the first flow passage, it is possible to ensure smooth circulation of the working fluid.

[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 allows heat to be transferred more slowly to the working fluid, reducing local temperature increases and decreases, thereby improving uniformity. More specifically, it is possible to suppress problems such as dry-out caused by rapid heating and obstruction of the flow of the working fluid caused by clogging of the 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 passage groove 142 is blocked by the first sheet 10 and the second sheet 20 to form a part of the hollow portion, which forms a flow passage for the working fluid and becomes the steam flow passage 4, which is the first flow passage through which steam flows. The relationship between the flow passage cross-sectional area of ​​the condensate flow passage 3 and the flow passage cross-sectional area of ​​the steam flow passage 4 can be considered to be similar to the relationship between the flow passage cross-sectional area of ​​the condensate flow passage 3 and the flow passage cross-sectional area of ​​the steam flow passage 4 described in the first embodiment.

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

[0173] As can be seen from Figure 39, the opening of groove 44a of the steam flow path communication groove 44 in 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 the 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 chamber] 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 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 temporarily attached to the first surface 130a of the third sheet 130, and the second sheet 20 is temporarily attached to the second surface 130b of the third sheet 130. The method of temporarily attaching is not particularly limited, but examples include resistance welding, ultrasonic welding, and adhesion with an adhesive. After the temporary joining, the first sheet 10, the second sheet 20, and the third sheet 130 are permanently joined together 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 insulation part 6 can be made into a vacuum, and by performing it in air or other gas, the insulation part 6 can be filled with the corresponding gas. If the insulation groove 136 is provided with pillars 136a and the insulation groove 140 is provided with pillars 140a, the insulation part 6 can be prevented from collapsing or expanding during joining, when the hollow part is decompressed as described below, and when the working fluid is injected. If a solid material is to be placed in the insulation part 6, the material can be placed in the insulation groove before joining.

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

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

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

[0180] In this embodiment, since 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, the heat transfer to the working fluid is slowed down, and local temperature increases and decreases are reduced, thereby improving uniformity. In other words, it is possible to suppress the flow of the working fluid being blocked by dry-out due to sudden heating or clogging of the condensate due to faster condensation than necessary, thereby improving the 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 a portion where local heat transfer is expected, such as a portion where a heat source (electronic component) is disposed, or conversely, an end portion of the vapor chamber that is separated from a heat source.

[0181] Furthermore, in the case where the introduction portion 37 and the introduction portion 41 are provided, there are areas surrounded by the introduction surface 37b and the introduction surface 41b and the first sheet 10 and the second sheet 20, 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.

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

[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 the heat insulating section 6 communicates with the condensate flow path 3 and the steam flow path 4. Fig. 47 shows an example in which the heat insulating section 6 is provided only in the steam flow path 4.

[0184] 3.Form 3 In the first and second embodiments, the introduction section 37 and the introduction section 39 have been described, but in the third embodiment, the introduction section will be described in detail. Therefore, the configuration other than the introduction section can be considered to be the same as in the first and second embodiments, and therefore the description will be omitted. In the first embodiment, the second surface 30b of the third sheet 30 is provided with a liquid flow path groove 40, and in the second embodiment, the second surface 130b of the third sheet 130 is provided with a heat insulating groove 140. However, since it is not necessary that these elements are 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 prevent the liquid flow path groove 40 and the heat insulating groove 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 in the first embodiment.

[0185] 3.1.Form 3a Figures 48(a) and 48(b) are diagrams for explaining 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 explained 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 addition, in this embodiment, an introduction portion 241 is provided in the inner liquid flow path section 238. The introduction portion 241 is a portion formed on the boundary surface with the steam flow path groove 42, and is a portion that protrudes toward the steam flow path groove 42. Therefore, in this embodiment, the introduction portions 241 are disposed 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 at a position T from the first surface 30a (the top of the protruding portion 39a of the liquid flow path groove) in the thickness direction (z direction). 203 The introduction surface 241b has an apex 241a that protrudes most from the position of the inner liquid flow path groove 39, and is provided with an arc-shaped introduction surface 241b that is concave toward the inner liquid flow path section 238 in cross-sectional view from the apex 241a toward the liquid flow path groove 39. However, the introduction 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-sectional view. 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] According to such an introduction portion 241, condensate tends to collect on the introduction surface 241b, and the movement of the working fluid between the condensate flow path 3 and the steam flow path 4 through the introduction portion 241 becomes smooth, thereby improving the 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 the condensate. The surface roughness (ISO 25178) of the introduction surface can be measured, for example, by 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-mentioned configuration further has the following configuration. Figure 48(a) shows the W 205 The width of the inner liquid flow passage section 238 (the size in the direction in which the inner liquid flow passage section 238 and the steam flow passage groove 42 are arranged, and the largest value) is preferably 3000 μm or less, and may be 2000 μm or less, or may be 1500 μm or less. On the other hand, this width W 205 The width W is preferably 100 μm or more, may be 200 μm or more, or may be 400 μm or more. 205 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. 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 the W 207 The protrusion amount indicated by (the distance from the end of the protrusion 39a to the apex 241a) is preferably 1000 μm or less, 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 any 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 protrusion 39a to the top 241a of the introduction section 241, indicated by T 204 Then, T 203 T 204 The value obtained by dividing the T by the saturation temperature is preferably 0.05 or more, may be 0.15 or more, or may be 0.3 or more. 203 T 204 The value divided by may be 1.0 or less, may be 0.8 or less, or may be 0.6 or less. 203 T 204 The range of values ​​divided by T may be determined by a combination of any one of the multiple upper limit candidate values ​​and one of the multiple lower limit candidate values. 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 apex 241a is disposed at a position that is the center of the inner liquid flow path section 238 in the thickness direction.

[0191] Furthermore, as shown in FIG. 48(a), the width of the liquid flow channel 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 201The protruding 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 Then, the following relationship is preferably satisfied: 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, a description will be given of the first sheet 10, the second sheet, and the third sheet 30 being combined to form the vapor chamber 1. Figures 49(a) and 49(b) show views corresponding to Figures 18(a) and 18(b). In the cross section shown in Fig. 49(a), the steam flow path 4 and the steam flow path 3 are separated by a convex portion 39a, but the convex portion 39a has a communication opening 39b. Therefore, in the cross section shown in Fig. 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 communicate 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 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 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 moves through the steam passage 4, losing heat, and adheres to the wall surface of the steam passage 4. On the other hand, since steam is continuously flowing through the steam passage 4, the condensed liquid adheres to the wall surface of the steam passage 4, as shown by arrows C in Figures 49(a) and 49(b). 211 As shown by the arrows, the condensate moves to the condensate flow passage 3 as if being pushed by the steam. Since the condensate flow passage 3 has the communication openings 39b, the condensate is distributed to the plurality of condensate flow passages 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 portion is formed between the inlet surface 241b and the first sheet 10, and the condensate tends to accumulate here 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, for ease of viewing, some of the reference symbols are omitted in Figure 50, but Figure 49(a) can be referred to. In the same cross section as in FIG. 49(a), a rectangle is defined as region A, with 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. The area of ​​region A is A A Let us assume that. In the same cross section as in FIG. 49(a), the region of the steam flow passage 4 surrounded by the inlet surface 241b, the region A, the protrusion 39a, and the first sheet 10 is defined as region B, and the area of ​​the region B is defined as region A. B Let us assume that. In the same cross section as in FIG. 49(a), the area of ​​the condensate flow passage 3 closest to area B is area C, and its area is A. C Let us assume that. These A A , A B , A C It is preferred that: A A >AB >A C This relationship makes it easier to draw condensed working fluid from the steam flow path 4 to the condensate flow path 3, and also makes it possible to prevent the sudden outflow of vaporized liquid from the condensate flow path 3 to the steam flow path 4.

[0197] 3.2.Form 3b to 3h The figures shown below are diagrams for explaining other embodiment examples, 3b to 3h, focusing on the shape of the introduction part. All of these figures correspond to Fig. 49(a) and Fig. 49(b). These introduction part shapes can also be applied to the outer circumferential liquid flow path part. For convenience, in all of the embodiment examples, the reference numeral 238 denotes the inner liquid flow path part, the reference numeral 241 denotes the introduction part, the reference numeral 241a denotes the top part, and the reference numeral 241b denotes the introduction surface.

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

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

[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 form, the above-mentioned effects can be obtained.

[0201] 54(a) and 54(b), inlet surface 241b extending from top 241a has a convex arc shape toward steam flow path 4 in cross section. However, it does not have to be an arc shape, and may have a curved shape other than a convex arc shape toward steam flow path 4 in cross section. Even in this configuration, the above-mentioned effects can be obtained. 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 the capillary force can be efficiently utilized.

[0202] 55(a) and 55(b) is an example in which 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 type of configuration, the introduction surface 241b can be formed, and the above-mentioned effect can be achieved. However, from the viewpoint of utilizing stronger capillary force by narrowing the gap between the inlet surface and the first surface 10a, it is preferable that the apex 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-mentioned examples.

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

[0204] In the embodiment 3h in 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 the first sheet 10 and part of the third sheet 30 described above, and the second sheet 220 has the configuration of the second sheet 20 and part of the third sheet 30 described above, and by combining the two, a sealed space of the vapor chamber is formed. In this embodiment 3h, the introduction surface 241b from the top 241a of the introduction portion 241 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 form, the above-mentioned effects can be obtained.

[0205] In addition, this embodiment is an example in which the top 241a and the condensate flow path 3 are at the same position in the thickness direction (position in the z direction), and each of the above-mentioned embodiments has a different position in the thickness direction (position in the z direction) between the top and the condensate flow path. Any of them can be applied as necessary, but there is a tendency that a larger amount of condensate can be retained and introduced when the top and the condensate flow path are at different positions in the thickness direction (position in the z direction).

[0206] 4. Form 4 In the vapor chamber, in a temperature environment lower than the freezing point of the enclosed working fluid, the working fluid may freeze. In the case of a working fluid that expands when frozen, such as pure water, the vapor chamber may be deformed due to the volume expansion of the working fluid in the vapor flow path. In the case of such a problem, it is preferable to have a configuration that can suppress deformation and exhibit more stable performance even if the working fluid freezes and expands. 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 to the aspects 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 thermal diffusion are 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 includes an inner sheet 311 and a reinforcing sheet 312, and the second sheet 320 includes 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 disposed on the side of the inner sheet 311 opposite to the third sheet 30 side and constitutes the outer surface 10b. Similarly, the reinforcing sheet 322 is a sheet disposed on the side of the inner sheet 321 opposite to 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. The clad material refers to a laminated material in which a plurality of types of sheets are bonded to each other. 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 their adhesion. Furthermore, the two sheets may be diffusion bonded to fabricate the clad material. Similarly, the inner sheet 321 and the reinforcing sheet 322 may be configured as a clad material. The clad material refers to a laminated material in which a plurality of types of sheets are bonded to each other. 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 their adhesion. Furthermore, the two sheets may be diffusion bonded to fabricate the 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, and may contain, for example, copper or a copper alloy. In this case, the thermal conductivity of each sheet can be increased. Therefore, the heat dissipation efficiency of the vapor chamber 301 can be increased. In addition, when pure water is used as the working fluid, corrosion can be prevented. Note that other metal materials such as aluminum and titanium, and other metal alloy materials such as stainless steel can also be used as long as the desired heat dissipation efficiency can be obtained and corrosion can be prevented.

[0212] Reinforcing sheet 312 is made of a material having a higher yield strength than inner sheet 311, and reinforcing sheet 322 is made of a material having a higher yield strength than inner sheet 321. The yield strength here is defined as the stress at which the permanent deformation upon unloading is 0.2%. The specific material of the reinforcing sheet 312 and the reinforcing sheet 322 is not particularly limited, but it is preferable that the material is a metal material with good thermal conductivity and has the desired mechanical strength, and examples of the material include materials containing copper alloy, iron alloy, nickel, nickel alloy, titanium, titanium alloy, and aluminum alloy. Examples of the iron alloy include stainless steel, Invar material (iron alloy containing nickel), and Kovar (iron alloy containing cobalt).

[0213] The thickness of the inner sheet 311, 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 sheet 311, 312, and also to prevent impurities contained in the material constituting the reinforcing sheet 312, 322 from precipitating on the third sheet 30 side through the pinholes. On the other hand, by making it 100 μm or less, it is possible to prevent the thickness of the vapor chamber 301 from becoming thick. The thickness of the inner sheet 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 thicknesses of the reinforcing sheets 312 and 322 may be greater than the thicknesses of the inner sheets 311 and 321. However, from the viewpoint of enhancing the reinforcing function, the reinforcing sheet 321 is preferably thicker than the 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 sheet. The specific thickness of the reinforcing sheet 312 and the reinforcing sheet 322 is not particularly limited, but is, for example, 3 μm or more and 100 μm or less. By making the thickness 3 μm or more, effective reinforcement can be achieved. On the other hand, by making the thickness 100 μm or less, the thickness of the vapor chamber 301 can be prevented from increasing. It is more preferably 5 μm or more and 50 μm or less, and even more preferably 9 μm or more and 25 μm or less.

[0215] Furthermore, 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 can suppress the occurrence of warping in the sheet on which the 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 forming 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 acidic 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 groove 39 of the inner liquid flow path 38, the communicating opening 39b, and the vapor flow path groove 42. At this time, the openings corresponding to the liquid flow path groove 39 and the communicating opening 39b can be formed to be smaller in width than the liquid flow path groove 39 and the communicating opening 39b. On the other hand, the opening corresponding to the vapor flow path groove 42 can be formed to have 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 groove 40, the communicating opening 40b, and the vapor flow path groove 42 of the inner liquid flow path 38. At this time, the openings corresponding to the liquid flow path groove 40 and the communicating opening 40b can be formed to be smaller in width than the liquid flow path groove 40 and the communicating opening 40b. On the other hand, the opening corresponding to the vapor flow path groove 42 can be formed 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 the liquid flow path groove 39, the communicating openings 39b, the liquid flow path portion 40, the communicating openings 40b, and the vapor flow path groove 42 are formed. Note that, 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 as the etching solution.

[0223] As described above, when the openings of the resist film 340 and the resist film 341 corresponding to the liquid flow channel 39, the communicating opening 39b, the liquid flow channel 40, and the communicating opening 40b are formed with a width smaller than the width of the groove, the amount of etching liquid entering the openings is reduced, and the etching rate at this portion is reduced. Therefore, the depth of the liquid flow channel 39, the communicating opening 39b, the liquid flow channel 40, and the communicating opening 40b can be made shallow. On the other hand, the openings of the resist film 340 and the resist film 341 corresponding to the vapor flow channel 42 are formed with the same width as the vapor flow channel 42 on the first surface 30a and the second surface 30b, so that the amount of etching liquid entering the openings is ensured, and the etching depth for forming the vapor flow channel 42 can be ensured (as a result, the vapor flow channel 42 penetrates in the thickness direction).

[0224] In addition, in order to form a portion that does not penetrate the groove 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 manner, 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 in which the reinforcing sheet 322 is laminated on the inner sheet 321 is prepared. The method for each preparation step is not particularly limited, but a material manufactured as a clad material can be used. As another method, the inner sheets 311, 312 may be formed by plating the reinforcing sheets 311, 322 formed from a rolled material. In this case, an adhesive layer may be interposed between the reinforcing sheets 312, 322 and the inner sheets 311, 321 to improve the bonding between them. Examples of the adhesive layer include a strike plating layer and a seed layer. For example, when the reinforcing sheets 312, 322 are formed from stainless steel and the inner sheets 311, 321 are formed from copper, a strike plating layer containing a material such as nickel or copper may be interposed, or a seed layer containing a material such as titanium or molybdenum may be interposed by sputtering. The thickness of the strike plating 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 a 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 thereon 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 fixing is not particularly limited, but may be, for example, resistance welding. In this case, resistance welding may be performed in spots using an electrode rod (not shown). Laser welding may be performed instead of resistance welding.

[0229] After the temporary fixing step, as shown in Fig. 64, the first sheet 310, the second sheet 320, and the third sheet 30 are permanently bonded by diffusion bonding as a bonding step. Diffusion bonding is a method in which the first sheet 310 and the third sheet 30 to be bonded are closely attached to each other, and the third sheet 30 and the second sheet 320 are closely attached to each other, and 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 them by utilizing the diffusion of atoms that occurs at the bonding surface. In diffusion bonding, the materials constituting each sheet are heated to a temperature close to the melting point, but the temperature is lower than the melting point, so that it is possible to prevent each sheet from melting and deforming.

[0230] After the joining step, a sealing step is performed in which the working fluid is sealed into the hollow portion 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 sheet and the second sheet are plated and then the sheets are laminated, but this is not limiting, and the sheets may be plated after being laminated. In this way, a plated layer is also formed on the side surfaces.

[0232] [Vapor chamber function] The operation process for cooling the heat source in the vapor chamber 301 is the same as that described above, so a description thereof will be omitted here. On the other hand, an electronic device equipped with vapor chamber 301 may be placed in an environment with a temperature lower than the freezing point of the working fluid. In this case, the working fluid freezes, and depending on the type of working fluid, it may expand due to freezing. For example, if the working fluid is pure water, it may freeze and expand in an environment below the freezing point. Due to this expansion, a force may be applied to the portion where the working fluid is stored, in a direction that expands vapor chamber 301 in the thickness direction.

[0233] In contrast, in the vapor chamber 301, the first sheet 310 is provided with a reinforcing sheet 312, and the second sheet 320 is provided with a reinforcing sheet 322. Since the first sheet 310 and the second sheet 320 are each reinforced, deformation can be suppressed even when subjected to a force due to freezing and expansion of the working fluid. This can suppress a decrease in flatness of the contact surface with the heat source at the portion receiving heat from the heat source and the contact surface with a member (e.g., a housing) at the portion releasing heat to the outside, and suppress the formation of gaps. In this case, it is possible to suppress the inhibition of heat conduction from the heat source to the vapor chamber 301 and heat conduction from the vapor chamber 301 to the outside.

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

[0235] 4.2.Form 4b Next, embodiment 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 are cross-sectional views corresponding to FIG.

[0236] In the vapor chamber 301' shown in Fig. 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 passages 3 and the steam flow passages 4. The concept behind the shapes of the condensate flow passages 3 and the steam flow passages 4 is the same as described above. Even in this embodiment, 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 disposed 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, of a metal mesh, metal powder, twisted metal wire, or the like. Even in this embodiment, 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 the fifth embodiment 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 the fourth embodiment. Furthermore, the 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, since the components other than the barrier sheets 413 and 423 can be considered to be similar to the vapor chamber 301 of embodiment 4, 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 is a material capable of preventing the metal elements constituting the reinforcing sheets 312, 322 from permeating toward the inner sheets 311, 321. Such a barrier material may contain, 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 among 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 an alloy film of tungsten and titanium. The barrier material may also be a combination of the above-mentioned four metal elements and other metal elements. An example of the alloy film in this case is an alloy film of nickel and tungsten.

[0240] The thickness of the barrier sheets 413, 423 is arbitrary as long as it can exert a 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 thickness of the vapor chamber 401 from becoming thick. Furthermore, by making the thickness 1000 nm or less, it is possible to prevent the thermal conduction from being hindered. From the viewpoint of exerting the barrier function more effectively, it is preferable that the thickness of the barrier sheets is 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, from an image obtained by cutting the vapor chamber 401 at an arbitrary position and imaging the cross section obtained by using a SEM (scanning electron microscope). 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 by energy dispersive X-ray analysis (EDX), and then scraping off the components further to analyze them. By repeating the component analysis in this manner, the components of the barrier sheets 413, 423 can be confirmed.

[0242] In addition, 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 the 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 the adhesion layer include a strike plating layer and a seed layer. For example, when 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 a copper material may be interposed by performing a sputtering process using a sputtering target material containing copper. The thickness of the strike plating 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 of a rolled material, and the reinforcing sheets 312, 322 may be formed by a plating process. Furthermore, either one of the cover sheets 413, 423 or 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 suppress the metal material forming the reinforcing sheet from diffusing into the inner sheet.

[0244] 6.Form 6 In the sixth embodiment, the shape of the liquid flow path groove in the third sheet is different from that of the vapor chambers in the first to fifth embodiments described above. As the other parts can be considered to be similar to those in the first to fifth embodiments, the description here focuses on the inner liquid flow path portion and omits a description of the other parts. However, the same 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 portions 552 which are a pair of convex portions adjacent to each other via the liquid flow path groove 551. 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 (y direction side in the figure) of the liquid flow path groove 551, and a second liquid flow path convex portion 552B arranged on the opposite side (opposite the y direction in the figure) from the one side of the liquid flow path groove 551. A plurality of first liquid flow path convex portions 552A are arranged in a first direction (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 (x direction in the figure) to form a second liquid flow path convex portion row 553B.

[0247] A first communication groove 554A is formed between each of the first liquid flow path convex portions 552A arranged in the first direction (x direction in the figure), and a second communication groove 554B is formed between each of the second liquid flow path convex portions 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, which loses heat from its vapor state and condenses into liquid on the surface of the vapor flow groove 42 (vapor flow path 4), 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 flows further into the liquid flow path groove 551 (condensed liquid flow path 3) by capillary action.

[0249] In the example shown in FIG. 68, the first liquid flow path convex portions 552A constituting the first liquid flow path convex portion row 553A are arranged at a constant pitch P 501 Similarly, the 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 the first liquid flow path convex row 553A and the second liquid flow path convex row 553B does not need to be complicated. It is also expected that the action of each pair of liquid flow path convex portions 552 can be equalized. For example, it is expected that the ease with which the liquid working fluid can enter the 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. However, the multiple first liquid flow path convex portions 552A and the multiple 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 linearly symmetrical in this way, the design of the first liquid flow path convex portion row 553A and the second liquid flow path convex portion row 553B does not become complicated. It is also expected that the action of each pair of liquid flow path convex portions 552 can be equalized. For example, it is expected that the ease with which the liquid working fluid can enter the 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 thereto 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 inclined with respect to the first direction so as to proceed from one side (the y direction side in the figure) of the liquid flow path groove 551 toward the liquid flow path groove 551 and proceed in the first direction (the x direction in the figure), and the second liquid flow path convex portion 552B extends in a direction inclined with respect to the first direction so as to proceed from the opposite side (the opposite side to the y direction in the figure) from the one side of the liquid flow path groove 551 toward the liquid flow path groove 551 and proceed in the first direction. 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 smaller than the distance on the opposite side to 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 configuration 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 configuration 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 composed of 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 more than 0° and less than 90°, but is preferably 30° or more 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 inclined with respect to the first direction so as to proceed in 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 (part 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 extends in a direction inclined with respect to the first direction so as to proceed in the first direction (x 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 convex portion 552B has a planar shape of a parallelogram composed of 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 greater than or equal to 30° and less than or equal to 60°.

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

[0260] Here, similarly to Fig. 68, in the example shown in Fig. 69, a first liquid flow path convex portion 552A constituting a pair of liquid flow path convex portions 552 and a second liquid flow path convex portion 552B adjacent thereto via a mainstream groove 551 are formed line-symmetrically with respect to the liquid flow path groove 551. 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 line-symmetrical with respect to the liquid flow path 551.

[0261] By making them linearly symmetrical in this way, the design of the first liquid flow path convex row 553A and the second liquid flow path convex row 553B does not become complicated. It is also expected that the action of each pair of liquid flow path convex portions 552 can be equalized. For example, it is expected that the ease with which the liquid working fluid can enter the 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, 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 do not have to be formed line-symmetrically with respect to liquid flow path groove 551. When they are not formed line-symmetrically, for example, the following effects can be achieved.

[0263] For example, when vapor of the working fluid flows in 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 tries 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 and the momentum of proceeding in the first direction (x direction) is reduced, so that it is possible to prevent the vapor from proceeding to the evaporation portion. The action 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 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 smaller on the first direction side than on the opposite side to the first direction side. For example, as shown in Fig. 69, in first liquid flow path convex portion 552A (parallelogram composed of four points P1, Q1, R1, and S1) and second liquid flow path convex portion 552B (parallelogram composed of four points P2, Q2, R2, and S2), the distance D1 between the ends on the first direction (x direction) side (distance between S1 and S2) is smaller than the distance D2 between the ends on the opposite side to the first direction (x direction) side (distance between R1 and R2).

[0265] Next, the action of the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B having the above-mentioned configuration will be described. Fig. 70 is a diagram for explaining the action 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. The first liquid flow path convex 552A and the second liquid flow path convex 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, as described using Figure 69, and the distance between the first liquid flow path convex 552A and the second liquid flow path convex 552B on the first direction side is smaller than the distance on the opposite side to 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 552A and the second liquid flow path convex 552B that constitute a pair of liquid flow path convexities 552 will, by capillary action, flow from the side where the distance between the first liquid flow path convex 552A and the second liquid flow path convex 552B is greater to the side where the distance between the first liquid flow path convex 552A and the second liquid flow path convex 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 552A and the second liquid flow path convex 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 made deeper on 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 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. This makes it possible to prevent a shortage of liquid working fluid in the evaporation section (section 4 close to the cooling target).

[0271] Moreover, by adopting the above-mentioned configuration, the depth of 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 becomes shallower, that is, the flow path cross-sectional area of ​​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 than that of 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, so that the capillary action works more strongly. Therefore, a stronger propulsive force is applied to the liquid working fluid in the liquid flow path groove 551, and the liquid flow path groove 551 (condensed liquid flow path 3) of the inner liquid flow path portion 538 can be transported in the first direction (x direction).

[0272] In addition, the liquid working fluid that passes through the end where the distance between the first liquid flow path convexity 552A and the second liquid flow path convexity 552B is shorter will diffuse in the area sandwiched between the next pair of liquid flow path convexities 552. However, 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 convexities 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-mentioned configuration can be obtained, for example, by performing half-etching using an etching solution to form the liquid flow path portion 50. In half-etching using an etching solution, a larger etched area has a tendency to be etched deeper than a smaller etched area.

[0274] Therefore, for example, the etching pattern used to form the inner liquid flow path portion 538 is an etching pattern in which the area of ​​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 (the above-mentioned D2 side) than the area of ​​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 (the above-mentioned D1 side) in the region sandwiched between the pair of liquid flow path convex portions 552. This allows the depth of 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 (the above-mentioned D2 side) to be deeper than the depth of 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 (the above-mentioned D1 side) in the depth of the region sandwiched between the pair of liquid flow path convex portions 552 formed by half etching using an etching liquid.

[0275] Next, the flow of the working fluid, which is steam, will be described. The first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B, and the first communication groove 554A and the second communication groove 554B, as described with reference to Fig. 69, 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) diffusing in the direction opposite to the first direction (x direction) through the vapor flow path groove 42 (vapor flow path 4) is unlikely to enter the liquid flow path groove 551 (condensate liquid flow path 3) through the first communication groove 554A and the second communication groove 554B, which are generally opposite to the diffusion direction.

[0276] That is, as shown in Fig. 68, since the evaporation section (part close to the cooling target) 4 is located on the upper side (x-direction side) in Fig. 70, the steam pressure is high on the upper side (x-direction side) and low on the lower side (opposite the x-direction) in Fig. 70. Therefore, the steam 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 steam 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 from the lower side (opposite the x-direction) to the upper side (x-direction).

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

[0278] Therefore, according to the vapor chamber 501 of this embodiment, the working fluid in a vapor state is effectively prevented 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 the heat transport efficiency.

[0279] In addition, the pressure of the steam immediately (momentarily) after the flow of vapor of the working fluid into the liquid flow path groove 551 (condensate liquid flow path 3) or the bumping of the liquid working fluid (i.e., the generation of steam) occurs is higher on the side where the distance between the first liquid flow path convex 552A and the second liquid flow path convex 552B of the pair of liquid flow path convexities 552 is smaller, and lower on the other sides (the side where the distance between the first liquid flow path convex 552A and the second liquid flow path convex 552B is larger, 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 tends to flow to 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 larger, or the first communication groove 554A side and the second communication groove 554B side) rather than 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. In other words, steam that flows into or is generated in the region sandwiched between the pair of liquid flow path convex portions 552 tends to flow less in the first direction (x direction) within the liquid flow path groove 551 (condensed 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 in the liquid flow path groove 551 (condensate flow path 3), the flowing in or generated steam can be prevented from proceeding 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 the 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 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 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 552A and the second liquid flow path convex 552B of a pair of liquid flow path convex 552 located on the opposite side of the first direction (x direction) of the pair of liquid flow path convex 552 into which steam flows or is generated is smaller, it is unlikely that steam will flow through this area of ​​high pressure into the pair of liquid flow path convex 552 located on the opposite side of the first direction (x direction).

[0284] Therefore, the steam is discharged through the first communication groove 554A and the second communication groove 554B to the steam flow path groove 42 (steam flow path 4). 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 above-mentioned steam discharge effect can be further promoted.

[0285] Next, the planar shapes (particularly corners) of the first liquid flow path convex portion 552A and the second liquid flow path convex portion 552B will be described in detail with reference to Fig. 71. As described below, the inner liquid flow path portion 538 is formed by performing half etching on a metal material sheet using an etching solution. Therefore, the planar shapes of 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 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, and has sharp corners rounded to have curved portions 555, 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 above-mentioned various effects of vapor chamber 501 of this embodiment can be achieved. The same applies to second liquid flow path convex portion 552B.

[0287] 6.2.Form 6b Next, the vapor chamber according to embodiment 6b will be described with reference to FIG. The vapor chamber according to embodiment 6b differs from the vapor chamber according to embodiment 6a in the form of its inner liquid flow path portion, but the other configurations can be the same as those of the vapor chamber according to embodiment 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 of 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 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 connecting grooves, the plurality of connecting grooves including a first connecting groove arranged on one side of the reference main stream groove and a second connecting groove arranged on the other side of the reference main stream groove, the first connecting 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 stream groove, and the second connecting 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] Moreover, the first connecting grooves are aligned in the direction in which the first connecting grooves extend, and the second connecting grooves are aligned in the direction in which the second connecting 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 inner 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 (the Y direction side in the figure) of the reference main flow groove 551 is the first convex row (553'A, 553'B), and the convex row on the other side (the opposite side to the y direction in the figure) of the reference liquid flow path groove 551' is the second convex row (553'D, 553'C).

[0293] To put it more simply, in the example shown in Figure 72, a first convex row 553'A, a liquid flow path groove 551'A, a first convex row 553'B, a reference main groove 551', a second convex row 553'D, a liquid flow path groove 551'B, and a 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 connecting 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) between the direction in which the first connecting grooves 554'A, 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. The angle θ3 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°.

[0297] In addition, each of the second connections 534'D, 554'C extends in a direction inclined relative to the first 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'.

[0298] 72, the angle (acute angle) between the direction in which the second connecting grooves 554'D, 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] Moreover, the first connecting grooves 554'A, 554'B are aligned in the direction in which the first connecting grooves extend, and the second connecting grooves 554'D, 554'C are aligned in the direction in which the second connecting grooves extend.

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

[0301] By arranging in this way, the design of the multiple first and second communication grooves can be made simple. It is also expected that the functions of each communication groove can be equalized. For example, it is expected that the ease with which the liquid working fluid can enter each liquid flow path groove (condensate flow path) from each of the multiple first communication grooves and the multiple second communication grooves can be equalized.

[0302] As described above, the vapor chamber 501' has a plurality of liquid flow passage grooves (551', 551'A, 551B) and a plurality of convex rows (553'A, 553'B, 555'C, 553'D) extending in the first direction with these liquid flow passage grooves interposed therebetween, so that the concave-convex structure of the inner liquid flow passage section 538' of the vapor chamber 501' can be made more complex, and the surface area of ​​the inner liquid flow passage section 538' can be made larger. Therefore, the amount of transport of the working fluid by capillary action can be increased, and the transport efficiency can be improved.

[0303] Moreover, 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-mentioned configuration 6a, the working fluid of vapor that diffuses in the direction opposite to the first direction (x direction) through the vapor flow path 4 is expected to have an effect that it is difficult for the working fluid to enter the liquid flow path groove (condensed liquid flow path) through the first communication groove 554'A and the second communication groove 554'C, which are in the direction roughly opposite to the diffusion direction.

[0304] 6.3.Form 6c Next, the vapor chamber according to 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 the embodiment 6b have a configuration that extends in a direction inclined with respect to the first direction. Therefore, similar to the vapor chamber 501 according to the embodiment 6a, it is expected that the vapor working fluid that diffuses in the direction opposite to the first direction (x direction) through the vapor flow path portion is unlikely to enter the liquid flow path groove through the first communication groove 554'A or the second communication groove 554'C that is roughly opposite to the diffusion direction.

[0306] However, in the vapor chamber 501' described above, unlike the vapor chamber 501 according to the embodiment 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 constituting a pair of liquid flow path convex portions is not smaller on the first direction side than on the opposite side to the first direction side, as in the vapor chamber 501 according to the embodiment 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 to the first direction side.

[0308] And, because of this configuration, the liquid working fluid that has passed through the end portion on 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 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 the liquid working fluid present in the region sandwiched between the pair of liquid flow path convex portions 552, it is expected that the effect of more effectively preventing the working fluid in vapor form from entering the liquid flow path portion 551 (condensed liquid flow path 3) from the first communication groove 554A and the second communication groove 554B can be achieved.

[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 constant.

[0310] Therefore, in terms of the effect of the vapor chamber 501 of form 6a, i.e., the effect of more effectively preventing the vapor working fluid from entering 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 FIG. 72, each of the first connecting grooves 554'A, 554'B is aligned in the extension direction of the first connecting groove, and each of the second connecting grooves 554'D, 554'C is aligned in the extension direction of the second connecting groove.

[0312] For example, as shown in FIG. 72, first connecting grooves 554'A and 554'B are arranged in the extension direction of the first connecting groove, i.e., in the direction that 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 extension direction of the second connecting groove, i.e., in the direction that 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 working fluid in the form of steam that has infiltrated from the first communication groove 554'A located on the outer side of the reference liquid flow path groove 551' may easily infiltrate into the reference liquid flow path groove 551' (condensate flow path 3) by passing through the first communication groove 554'B located on the inner side because there is no liquid flow path convex portion in the direction in which this first communication groove extends. Similarly, the working fluid in the form of steam that has infiltrated from the second communication groove 554'C located on the outer side of the reference liquid flow path groove 551' may easily infiltrate into the reference liquid flow path groove 551' (condensate flow path 3) by passing through the second communication groove 554'D located on the inner side because there is no liquid flow path convex portion in the direction in which this second communication groove extends.

[0314] Therefore, in the vapor chamber of form 6c, a liquid flow path convex portion exists in the direction in which the communication groove extends. Note that the vapor chamber of form 6c differs from the vapor chambers of forms 6a and 6b in the form of its inner liquid flow path portion, but the other configurations can be the same as the vapor chamber of 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 inner liquid flow path portion 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 from the y-direction side: a first convex portion row 553''A, a liquid flow path groove 551''A, a first convex portion row 553''B, a reference liquid flow path groove 551'', a second convex portion row 553''D, a liquid flow path groove 551''B, and a 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 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.

[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 FIG. 73, the angle (acute angle) 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 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 FIG. 73, the angle (acute angle) between 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 with respect to the reference liquid flow groove is referred to as the outer first convex row, and the first convex row arranged on the inside with respect to the reference liquid flow 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 with respect to the reference liquid flow groove is referred to as the outer second convex row, and the second convex row arranged on the inside with respect to the reference liquid flow groove is referred to as the inner second convex row, then the liquid flow path convexities that constitute the inner first convex row are arranged in the direction in which the first connecting groove that passes between the liquid flow path convexities that constitute the outer first convex row extends, and the liquid flow path convexities that constitute the inner second convex row are arranged in the direction in which the second connecting groove that passes between the liquid flow path convexities that constitute the outer second convex row extends.

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

[0323] Furthermore, in the direction in which the first connecting groove 554''A extends, passing 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 direction indicated by the thick dashed arrow in the figure), 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.

[0324] Therefore, the working fluid in the form of steam that has infiltrated from first connecting groove 554''A, which is located further outboard of reference liquid flow path groove 551'', has its flow blocked by liquid flow path convex portion 552''B which exists in the direction in which this first connecting groove extends, making it less likely to infiltrate into reference liquid flow path groove 551'', which is located further inboard. In addition, since liquid flow path convex portion 552''B disperses the flow of steam, the pressure of the steam also decreases. Therefore, it becomes even more difficult for the working fluid to infiltrate into reference liquid flow path groove 551''.

[0325] Similarly, in the direction in which the second connecting groove 554''C that 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, extends (the direction indicated by the thick dashed arrow in the figure), 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.

[0326] Therefore, the working fluid in the form of steam that has infiltrated from second connecting groove 554''C, which is located further outboard than reference liquid flow path groove 551'', has its flow blocked by liquid flow path convex portion 552''D which exists in the direction in which this first connecting groove extends, making it less likely to infiltrate into reference liquid flow path groove 551'', which is located further inboard. In addition, since liquid flow path convex portion 552''D disperses the flow of steam, the pressure of the steam also decreases. Therefore, it becomes even more difficult for the working fluid to infiltrate into 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 the heat transport efficiency.

[0328] Also, similar to the vapor chamber 501' shown in FIG. 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 between them, so that the uneven structure of the inner liquid flow path portion 538'' of the vapor chamber 501'' can be made more complex, thereby increasing the surface area of ​​the inner liquid flow path portion 538''. Therefore, the amount of working fluid transported by capillary action can be increased, and the transport efficiency can be improved.

[0329] The above-described embodiments of the present disclosure are not limited to the above, and may be embodied by modifying the components without departing from the spirit of the present disclosure. In addition, the components disclosed in the above-described embodiments may be combined to produce various 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 sheet 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 passage 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 Groove for insulation 138 Inner liquid flow path section (liquid flow path section) 140 Groove for insulation 201 Vapor Chamber 230 Third Sheet 238 Inner liquid flow path section (liquid flow path section) 241 Introduction 301 Vapor Chamber 310 First Sheet 311 Inner sheet 312 Reinforcement sheet 320 Second Sheet 321 Inner sheet 322 Reinforcement sheet 401 Vapor Chamber 410 First Sheet 411 Inner sheet 413 Barrier Sheet 420 Second Sheet 423 Barrier Sheet 501 Vapor Chamber 538 Inner liquid flow path section 551 Steam flow channel 552 A pair of liquid flow path protrusions 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 part row 554A First connecting groove 554B Second connecting groove

Claims

[Claim 1] A vapor chamber in which a working fluid is sealed in a sealed space, It consists of three overlapping sheets, Among the three sheets, the sheet disposed at the center includes a first flow path penetrating the sheet in a thickness direction and extending along a sheet surface, and a liquid flow path portion adjacent to the first flow path and having a second flow path, the second flow path is provided as a groove on each of one surface and the other surface in a thickness direction of the liquid flow path portion, the first flow path and the second flow path are communicated with each other through communication openings provided on one surface and the other surface of the liquid flow path section in a thickness direction, Vapor chamber.

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