Main body sheet for vapor chamber, vapor chamber and electronic device

Abstract

A vapor chamber body sheet according to the present invention comprises a first body surface, a second body surface provided on the reverse side from the first body surface, and a through space that extends from the first body surface to the second body surface. The through space extends in a first direction in a plan view. When viewed in a cross section perpendicular to the first direction, the through space has a first opening positioned on the first body surface and a second opening positioned on the second body surface. The second opening extends from a region that, in a plan view, overlaps the first opening to a position that, in a plan view, overlaps a first groove.

Description

[Technical Field]

[0001] The present invention relates to a main body sheet for a vapor chamber, a vapor chamber, and an electronic device. [Background technology]

[0002] Electronic devices, such as mobile terminals like handheld terminals or tablet terminals, use electronic devices that generate heat. Examples of such electronic devices include central processing units (CPUs), light-emitting diodes (LEDs), and power semiconductors. Such electronic devices are cooled by heat dissipation devices such as heat pipes (see, for example, Patent Documents 1 and 2). In recent years, thinner heat dissipation devices have also been required to make electronic devices thinner. Vapor chambers, which can be thinner than heat pipes, have been developed as heat dissipation devices. Vapor chambers efficiently cool electronic devices by absorbing heat from the electronic device and diffusing it inside the enclosed working fluid.

[0003] More specifically, the working liquid (working fluid) in the vapor chamber receives heat from the electronic device in the portion (evaporator) close to the electronic device. The heated working liquid evaporates and becomes working vapor. The working vapor diffuses away from the evaporator within the vapor flow path formed in the vapor chamber. The diffused working vapor cools and condenses to become working liquid. A liquid flow path with a capillary structure (wick) is provided within the vapor chamber. The working liquid flows through the liquid flow path and is transported toward the evaporator. The working liquid transported to the evaporator then receives heat again in the evaporator and evaporates. In this way, the working fluid circulates within the vapor chamber while repeatedly changing phases, i.e., evaporating and condensing, and dissipates heat from the electronic device. As a result, the heat dissipation efficiency of the vapor chamber is improved. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-82698 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-017702 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a main body sheet for a vapor chamber, a vapor chamber, and an electronic device that can improve cooling efficiency. [Means for solving the problem]

[0006] As a first solution, the present invention provides: A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; a plurality of first grooves provided on the first body surface and communicating with the through-space, the plurality of first grooves extending in a first direction; The through space extends in a first direction in a plan view, a main body sheet for a vapor chamber, wherein, when viewed in a cross section perpendicular to the first direction, the through space has a first opening located in the first main body surface and a second opening located in the second main body surface, and the second opening extends from a region overlapping with the first opening in a plan view to a position overlapping with the first groove in a plan view; to provide.

[0007] Furthermore, in the main body sheet for a vapor chamber according to the first solving means described above, When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first body surface and defining the first opening, and a second spatial recess provided in the second body surface and defining the second opening, the second spatial recess communicating with the first spatial recess, the first spatial recess includes a pair of concavely curved first wall surfaces, the second spatial recess includes a pair of concavely curved second wall surfaces, The first wall surface and the second wall surface corresponding to each other are connected by a wall surface protrusion that protrudes toward the inside of the through space, When viewed in a cross section perpendicular to the first direction, the second spatial recess includes a flat surface that connects the corresponding second wall surface and the corresponding wall surface protrusion. This may be done.

[0008] Furthermore, in the main body sheet for a vapor chamber according to the first solving means described above, When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first body surface and defining the first opening, and a second spatial recess provided in the second body surface and defining the second opening, the second spatial recess communicating with the first spatial recess, the first spatial recess includes a pair of concavely curved first wall surfaces, the second spatial recess includes a pair of concavely curved second wall surfaces, The first wall surface and the second wall surface corresponding to each other are connected by a wall surface protrusion that protrudes toward the inside of the through space, When viewed in a cross section perpendicular to the first direction, the second spatial recess includes a convex surface connecting the second wall surface and the wall surface protrusion corresponding to each other, The convex surface includes a spatial convex portion extending in the first direction and protruding toward the second main body surface. This may be done.

[0009] Furthermore, in the main body sheet for a vapor chamber according to the first solving means described above, The convex surface includes a plurality of the spatial convex portions spaced apart from each other. This may be done.

[0010] Furthermore, in the main body sheet for a vapor chamber according to the first solving means described above, When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first body surface and defining the first opening, and a second spatial recess provided in the second body surface and defining the second opening, the second spatial recess communicating with the first spatial recess, the first spatial recess includes a pair of first wall surfaces that are convexly curved, The second spatial recess includes a pair of concavely curved second wall surfaces. This may be done.

[0011] Furthermore, in the main body sheet for a vapor chamber according to the first solving means described above, When viewed in a cross section perpendicular to the first direction, the second opening extends from a region overlapping with the first opening in a plan view to positions overlapping with the first groove on both sides of the first opening. This may be done.

[0012] Furthermore, in the main body sheet for a vapor chamber according to the first solving means described above, a frame body portion formed in a frame shape in a plan view and extending from the first main body surface to the second main body surface, the frame body portion defining the through space; a land portion provided on an inner side of the frame portion, the land portion extending in the first direction and extending from the first main body surface to the second main body surface; the first opening and the second opening are located between the frame portion and the land portion, the first groove is located on the first body surface of the land portion; When viewed in a cross section perpendicular to the first direction, the second opening extends from a region overlapping with the first opening in a plan view to a position overlapping with the first groove located in the land portion in a plan view, and extends further outward from the frame body portion than the first opening. This may be done.

[0013] Furthermore, the present invention provides, as a second solution, A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; The through space extends in a first direction in a plan view, When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first main body surface and a second spatial recess provided in the second main body surface and communicating with the first spatial recess, the first spatial recess includes a pair of first wall surfaces, the second spatial recess includes a pair of second wall surfaces, one of the first wall surfaces of the first spatial recess and the corresponding second wall surface of the second spatial recess are connected by a first wall surface protrusion, The first wall surface protrusion protrudes toward the inside of the through-space, the first wall surface protrusion is disposed offset from an intermediate position between the first main body surface and the second main body surface in a normal direction of the first main body surface, a main body sheet for a vapor chamber, wherein the first wall surface of the first spatial recess located on the opposite side to the first wall surface protrusion portion and the corresponding second wall surface of the second spatial recess are formed in a continuous concave shape from the first wall surface to the second wall surface; to provide.

[0014] In the main body sheet for a vapor chamber according to the second solution, the through space has a first opening located in the first body surface and defined by the first spatial recess, and a second opening located in the second body surface and defined by the second spatial recess; When viewed in a cross section perpendicular to the first direction, the center of the first opening is shifted from the center of the second opening. This may be done.

[0015] Furthermore, the present invention provides, as a third solution, A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; The through space extends in a first direction in a plan view, When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first main body surface and a second spatial recess provided in the second main body surface and communicating with the first spatial recess, the first spatial recess includes a pair of first wall surfaces, the second spatial recess includes a pair of second wall surfaces, one of the first wall surfaces of the first spatial recess and the corresponding second wall surface of the second spatial recess are connected by a first wall surface protrusion, The first wall surface protrusion protrudes toward the inside of the through-space, the first wall surface protrusion is disposed offset from an intermediate position between the first main body surface and the second main body surface in a normal direction of the first main body surface, the through space has a first opening located in the first body surface and defined by the first spatial recess, and a second opening located in the second body surface and defined by the second spatial recess; a main body sheet for a vapor chamber, wherein a center of the first opening is shifted from a center of the second opening when viewed in a cross section perpendicular to the first direction; to provide.

[0016] Furthermore, in the main body sheet for a vapor chamber according to the third solving means, a frame body portion formed in a frame shape in a plan view; a land portion provided on the inside of the frame body portion, the land portion extending in the first direction and defining the through space between the frame body portion and the land portion; When the width of the land portion is w1, the deviation amount between the center of the first opening and the center of the second opening is 0.05 mm to (0.8×w1) mm. This may be done.

[0017] Furthermore, in the main body sheet for a vapor chamber according to the third solving means, The device further includes a plurality of first grooves provided on the first body surface and communicating with the through-space, the first wall surface protrusion is disposed closer to the first body surface than the intermediate position; This may be done.

[0018] Furthermore, in the main body sheet for a vapor chamber according to the third solving means, the first wall surface of the first spatial recess located on the opposite side to the first wall surface protrusion is connected to the corresponding second wall surface of the second spatial recess by a second wall surface protrusion, The second wall surface protrusion protrudes toward the inside of the through-space, The second wall surface protrusion is disposed offset from an intermediate position between the first main body surface and the second main body surface in the normal direction. This may be done.

[0019] Furthermore, in the main body sheet for a vapor chamber according to the third solving means, the second wall surface protrusion is disposed closer to the first body surface than the intermediate position; This may be done.

[0020] Furthermore, the present invention provides, as a fourth solution, A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; The through space extends in a first direction in a plan view, When viewed in a cross section perpendicular to the first direction, the through-space has a first spatial recess provided in the first body surface, a second spatial recess provided in the second body surface and communicating with the first spatial recess, and a third spatial recess provided in the second body surface, the third spatial recess being located on both sides of the second spatial recess and communicating with the second spatial recess, the second spatial recess includes a pair of second wall surfaces, the third spatial recess includes a third wall surface, Each of the second wall surfaces of the second spatial recesses and the corresponding third wall surface of the third spatial recesses are connected by a third wall surface protrusion, a main body sheet for a vapor chamber, wherein the third wall surface protrusion protrudes toward the second main body surface; to provide.

[0021] In addition, in the main body sheet for a vapor chamber according to the fourth solving means, the first spatial recess includes a pair of first wall surfaces, one of the first wall surfaces of the first spatial recess and the corresponding second wall surface of the second spatial recess are connected by a first wall surface protrusion, The first wall surface protrusion protrudes toward the inside of the through-space, The first wall surface protrusion is disposed offset from an intermediate position between the first main body surface and the second main body surface in a normal direction of the first main body surface. This may be done.

[0022] In addition, in the main body sheet for a vapor chamber according to the fourth solving means, The device further includes a plurality of first grooves provided on the first body surface and communicating with the through-space, the first wall surface protrusion is disposed closer to the first body surface than the intermediate position; This may be done.

[0023] In addition, in the main body sheet for a vapor chamber according to the fourth solving means, the first wall surface of the first spatial recess located on the opposite side to the first wall surface protrusion is connected to the corresponding second wall surface of the second spatial recess by a second wall surface protrusion, The second wall surface protrusion protrudes toward the inside of the through-space, The second wall surface protrusion is disposed offset from an intermediate position between the first main body surface and the second main body surface in the normal direction. This may be done.

[0024] In addition, in the main body sheet for a vapor chamber according to the fourth solving means, the second wall surface protrusion is disposed closer to the first body surface than the intermediate position; This may be done.

[0025] In addition, in the main body sheet for a vapor chamber according to the fourth solving means, The first wall surface of the first spatial recess located on the opposite side to the first wall surface protrusion portion and the corresponding second wall surface of the second spatial recess are formed in a continuous concave shape from the first wall surface to the second wall surface. This may be done.

[0026] In addition, in the main body sheet for a vapor chamber according to the fourth solving means, the through space has a first opening located in the first body surface and defined by the first spatial recess, and a second opening located in the second body surface and defined by the second spatial recess; When viewed in a cross section perpendicular to the first direction, the center of the first opening is shifted from the center of the second opening. This may be done.

[0027] In addition, in the main body sheet for a vapor chamber according to the fourth solving means, a frame body portion formed in a frame shape in a plan view; a land portion provided on the inside of the frame body portion, the land portion extending in the first direction and defining the through space between the frame body portion and the land portion; When the width of the land portion is w1, the deviation amount between the center of the first opening and the center of the second opening is 0.05 mm to (0.8×w1) mm. This may be done.

[0028] Furthermore, the present invention provides, as a fifth solution, A main body sheet for a vapor chamber, a first body surface; a second body surface located opposite the first body surface; a through space penetrating the first body surface and the second body surface; a plurality of first grooves provided on the second body surface and communicating with the through-space; The through space has a curved first wall surface located on the side of the first main body surface and a curved second wall surface located on the side of the second main body surface, The first wall surface and the second wall surface meet at a protrusion formed to protrude into the through-space, the protrusion is located closer to the second body surface than an intermediate position between the first body surface and the second body surface, the first wall has a first wall end on the first body surface side; a vapor chamber main body sheet, the first wall surface end portion being located more inward of the through space than the protrusion portion in a plan view; to provide.

[0029] In addition, in the main body sheet for a vapor chamber according to the fifth solving means, the second wall has a second wall end on the second body surface side; When the distance between the second wall surface end and the protrusion in the width direction of the through space is Lp and the distance between the second wall surface end and the first wall surface end is Ls, the distance Ls is 1.05 times or more and 2 times or less of the distance Lp, This may be done.

[0030] In addition, in the main body sheet for a vapor chamber according to the fifth solving means, The plurality of first grooves are arranged in parallel with each other, A row of convex portions is provided between the adjacent first grooves, Each of the projection rows has a plurality of projections, the second wall has a second wall end on the second body surface side; When the distance between the second wall surface end and the first wall surface end is Ls, the distance Ls is 1.1 times or more and 10 times or less the width of the convex portion. This may be done.

[0031] Furthermore, the present invention provides, as a sixth solution, The first sheet and The second sheet, a vapor chamber including a main body sheet for the vapor chamber according to each of the first to sixth solutions, the main body sheet being interposed between the first sheet and the second sheet; to provide.

[0032] Furthermore, as a seventh solution, the present invention provides: A vapor chamber containing a working fluid, The first sheet and The second sheet, a main body sheet for a vapor chamber interposed between the first sheet and the second sheet, The main body sheet is a first body surface; a second body surface located opposite the first body surface; a through space penetrating the first body surface and the second body surface; a plurality of first grooves provided on the second body surface and communicating with the through-space; The through space has a curved first wall surface located on the side of the first main body surface and a curved second wall surface located on the side of the second main body surface, The first wall surface and the second wall surface meet at a protrusion formed to protrude into the through-space, the protrusion is located closer to the second body surface than an intermediate position between the first body surface and the second body surface, the first wall has a first wall end on the first body surface side; a vapor chamber, the first wall surface end being located more inwardly of the through space than the protrusion in a plan view; to provide.

[0033] In addition, in the vapor chamber according to the seventh solving means, the second wall has a second wall end on the second body surface side; When the distance between the second wall surface end and the protrusion in the width direction of the through space is Lp and the distance between the second wall surface end and the first wall surface end is Ls, the distance Ls is 1.05 times or more and 2 times or less of the distance Lp, This may be done.

[0034] In addition, in the vapor chamber according to the seventh solving means, The plurality of first grooves are arranged in parallel with each other, A row of convex portions is provided between the adjacent first grooves, Each of the projection rows has a plurality of projections, the second wall has a second wall end on the second body surface side; When the distance between the second wall surface end and the first wall surface end is Ls, the distance Ls is 1.1 times or more and 10 times or less the width of the convex portion. This may be done.

[0035] Furthermore, as an eighth solution, the present invention provides: Housing and an electronic device contained within the housing; an electronic device comprising: a vapor chamber according to the sixth or seventh solution in thermal contact with the electronic device; to provide. [Effects of the Invention]

[0036] According to the present invention, the cooling efficiency can be improved. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a schematic perspective view illustrating an electronic device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a top view showing the vapor chamber according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view of the vapor chamber taken along line AA in FIG. [Figure 4] FIG. 4 is a top view of the lower sheet of FIG. [Figure 5] FIG. 5 is a bottom view of the upper sheet of FIG. [Figure 6] FIG. 6 is a top view of the wick sheet of FIG. [Figure 7] FIG. 7 is a bottom view of the wick sheet of FIG. [Figure 8A] FIG. 8A is an enlarged partial cross-sectional view of FIG. 3 showing the second steam passage. [Figure 8B] FIG. 8B is a partially enlarged cross-sectional view showing an example of the upper opening. [Figure 8C] FIG. 8C is a partially enlarged cross-sectional view showing an example of the upper opening. [Figure 8D] FIG. 8D is a partially enlarged cross-sectional view showing an example of the upper opening. [Figure 8E] FIG. 8E is a partially enlarged cross-sectional view showing an example of the upper opening. [Figure 8F] FIG. 8F is a schematic diagram for explaining a flat surface. [Figure 9] FIG. 9 is a partially enlarged top view of the liquid flow path portion shown in FIG. [Figure 10] FIG. 10 is a partially enlarged cross-sectional view of FIG. 3 showing the first steam passage. [Figure 11] FIG. 11 is a partially enlarged cross-sectional view showing a modification of the vapor chamber shown in FIG. 8A. [Figure 12] FIG. 12 is a partially enlarged cross-sectional view showing a modification of the vapor chamber shown in FIG. 8A. [Figure 13] FIG. 13 is a partially enlarged cross-sectional view showing a modification of the vapor chamber shown in FIG. 8A. [Figure 14] FIG. 14 is a partially enlarged cross-sectional view showing a modification of the vapor chamber shown in FIG. 8A. [Figure 15A] 15A is a modified example of the wick sheet shown in FIG. 6, and is a partially enlarged top view of FIG. [Figure 15B] FIG. 15B is a partially enlarged cross-sectional view showing the second steam passage in the second region shown in FIG. 15A. [Figure 16] FIG. 16 is a cross-sectional view showing a vapor chamber according to a second embodiment of the present invention, which corresponds to the cross section taken along line AA in FIG. [Figure 17] FIG. 17 is a partially enlarged cross-sectional view of FIG. [Figure 18] FIG. 18 is a view for explaining a wick sheet preparation step in the method for manufacturing a vapor chamber according to the second embodiment. [Figure 19] FIG. 19 is a view for explaining a resist forming step in the method for manufacturing a vapor chamber according to the second embodiment. [Figure 20] FIG. 20 is a view for explaining a resist patterning step in the method for manufacturing a vapor chamber according to the second embodiment. [Figure 21] FIG. 21 is a view for explaining an etching step in the method for manufacturing a vapor chamber according to the second embodiment. [Figure 22] FIG. 22 is a view for explaining a resist removing step in the method for manufacturing a vapor chamber according to the second embodiment. [Figure 23] FIG. 23 is a diagram for explaining a bonding step in the manufacturing method of the vapor chamber according to the second embodiment. [Figure 24] FIG. 24 is a partially enlarged cross-sectional view showing a modification of the vapor chamber shown in FIG. [Figure 25]FIG. 25 is a partially enlarged cross-sectional view showing another modified example of the vapor chamber shown in FIG. [Figure 26] FIG. 26 is a partially enlarged cross-sectional view showing a vapor chamber in the third embodiment of the present invention. [Figure 27] FIG. 27 is a view for explaining the first resist forming step in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 28] FIG. 28 is a view for explaining the first patterning step of the first resist in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 29] FIG. 29 is a view for explaining the first etching step in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 30] FIG. 30 is a view for explaining the first resist removing step in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 31] FIG. 31 is a view for explaining the second resist forming step in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 32] FIG. 32 is a view for explaining the second patterning step of the second resist in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 33] FIG. 33 is a view for explaining the second etching step in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 34] FIG. 34 is a view for explaining the second resist removal step in the method for manufacturing a vapor chamber according to the third embodiment. [Figure 35] FIG. 35 is a partially enlarged cross-sectional view showing a modification of the vapor chamber shown in FIG. [Figure 36] FIG. 36 is a top view showing a vapor chamber according to the fourth embodiment of the present invention. [Figure 37] 37 is a cross-sectional view of the vapor chamber taken along line BB in FIG. [Figure 38]FIG. 38 is a top view of the lower sheet of FIG. [Figure 39] FIG. 39 is a bottom view of the upper sheet of FIG. [Figure 40] FIG. 40 is a top view of the wick sheet of FIG. [Figure 41] FIG. 41 is a bottom view of the wick sheet of FIG. [Figure 42] FIG. 42 is a partially enlarged cross-sectional view of FIG. [Figure 43] 43 is a partially enlarged top view of the liquid flow path portion shown in FIG. [Figure 44] FIG. 44 is a diagram illustrating a method for manufacturing a vapor chamber according to the fourth embodiment. [Figure 45] FIG. 45 is a diagram illustrating a method for manufacturing a vapor chamber according to the fourth embodiment. [Figure 46] FIG. 46 is a diagram illustrating a method for manufacturing a vapor chamber according to the fourth embodiment. [Figure 47] FIG. 47 is a partially enlarged cross-sectional view showing the flow of the working fluid in the vapor channel portion according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios of the actual objects have been appropriately changed and exaggerated for the sake of convenience in illustration and understanding.

[0039] As used herein, geometric conditions, physical characteristics, terms specifying the degree of a geometric condition or physical characteristic, and numerical values ​​indicating a geometric condition or physical characteristic may be interpreted without being bound by strict meaning. These geometric conditions, physical characteristics, terms, and numerical values ​​may also be interpreted to include the range within which similar functionality can be expected. Examples of terms specifying geometric conditions include "length," "angle," "shape," and "arrangement." Examples of terms specifying geometric conditions include "parallel," "orthogonal," and "identical." Furthermore, for clarity of the drawings, the shapes of multiple parts that can be expected to have similar functionality are depicted in a regular pattern. However, without being bound by strict meaning, the shapes of the parts may differ from each other as long as the functionality can be expected. In the drawings, for convenience, boundary lines indicating the joining surfaces between components are shown as simple straight lines. However, they are not required to be strictly straight lines, and the shape of the boundary line is arbitrary as long as the desired joining performance can be expected.

[0040] (First embodiment) 1 to 15B, a main body sheet for a vapor chamber, a vapor chamber, and an electronic device according to a first embodiment of the present invention will be described. The vapor chamber 1 in this embodiment is housed in a housing H of the electronic device E together with an electronic device D that generates heat, and is a device for cooling the electronic device D. Examples of the electronic device E include mobile devices such as portable terminals and tablet terminals. Examples of the electronic device D include a central processing unit (CPU), a light-emitting diode (LED), and a power semiconductor. The electronic device D may also be referred to as a cooled device.

[0041] Here, an electronic device E equipped with a vapor chamber 1 according to this embodiment will be described first using a tablet terminal as an example. As shown in FIG. 1, the electronic device E includes a housing H, an electronic device D housed in the housing H, and a vapor chamber 1. In the electronic device E shown in FIG. 1, a touch panel display TD is provided on the front surface of the housing H. The vapor chamber 1 is housed in the housing H and is arranged so as to be in thermal contact with the electronic device D. The vapor chamber 1 receives heat generated by the electronic device D when the electronic device E is in use. The heat received by the vapor chamber 1 is released to the outside of the vapor chamber 1 via working fluids 2a and 2b, which will be described later. In this way, the electronic device D is effectively cooled. When the electronic device E is a tablet terminal, the electronic device D may be a central processing unit or the like.

[0042] Next, the vapor chamber 1 according to this embodiment will be described. As shown in FIGS. 2 and 3, the vapor chamber 1 has a sealed space 3 in which working fluids 2a and 2b are sealed. The working fluids 2a and 2b in the sealed space 3 repeatedly undergo phase changes, thereby effectively cooling the electronic device D of the electronic device E described above. Examples of the working fluids 2a and 2b include pure water, ethanol, methanol, acetone, and mixtures thereof. The working fluids 2a and 2b may have freeze-expansion properties. In other words, the working fluids 2a and 2b may be fluids that expand when frozen. Examples of the freeze-expansion working fluids 2a and 2b include pure water and aqueous solutions of pure water to which an additive such as alcohol has been added.

[0043] 2 and 3, the vapor chamber 1 includes a lower sheet 10, an upper sheet 20, a wick sheet 30 for the vapor chamber, a vapor flow path section 50, and a liquid flow path section 60. The wick sheet 30 is interposed between the lower sheet 10 and the upper sheet 20. The wick sheet 30 for the vapor chamber will hereinafter be simply referred to as the wick sheet 30. The vapor chamber 1 according to this embodiment has the lower sheet 10, the wick sheet 30, and the upper sheet 20 stacked in this order.

[0044] The vapor chamber 1 is generally formed in the shape of a thin flat plate. The planar shape of the vapor chamber 1 is arbitrary, but may be a rectangle as shown in FIG. 2. The planar shape of the vapor chamber 1 may be, for example, a rectangle with one side 1 cm and the other 3 cm, or a square with one side 15 cm. The planar dimensions of the vapor chamber 1 are arbitrary. In this embodiment, as an example, an example will be described in which the planar shape of the vapor chamber 1 is a rectangle with the X direction (described later) as the longitudinal direction. In this case, as shown in FIGS. 4 to 7, the lower sheet 10, the upper sheet 20, and the wick sheet 30 may have the same planar shape as the vapor chamber 1. Furthermore, the planar shape of the vapor chamber 1 is not limited to a rectangle, but may be any shape, such as a circle, an ellipse, an L-shape, or a T-shape.

[0045] 2, the vapor chamber 1 has an evaporation region SR where the working fluids 2a and 2b evaporate, and a condensation region CR where the working fluids 2a and 2b condense. The working vapor 2a is a working fluid in a gaseous state, and the working fluid 2b is a working fluid in a liquid state.

[0046] The evaporation region SR is a region that overlaps with the electronic device D in a planar view and is a region where the electronic device D is attached. The evaporation region SR may be located anywhere in the vapor chamber 1. In this embodiment, the evaporation region SR is formed on one side of the vapor chamber 1 in the X direction (the left side in FIG. 2 ). Heat from the electronic device D is transferred to the evaporation region SR, and this heat causes the working fluid 2b to evaporate in the evaporation region SR. The heat from the electronic device D may be transferred not only to the region that overlaps with the electronic device D in a planar view, but also to the surrounding area of ​​the region. Therefore, the evaporation region SR includes the region that overlaps with the electronic device D and the surrounding area in a planar view. Here, the planar view may refer to a state where the vapor chamber 1 is viewed from a direction perpendicular to the surface that receives heat from the electronic device D and the surface that releases the received heat. The heat-receiving surface corresponds to a first lower sheet surface 10a of the lower sheet 10, which will be described later. The heat-releasing surface corresponds to a second upper sheet surface 20b of the upper sheet 20, which will be described later. For example, as shown in FIG. 2, the state in which the vapor chamber 1 is viewed from above or below corresponds to a plan view.

[0047] The condensation region CR is a region that does not overlap with the electronic device D in a plan view, and is a region where the working vapor 2a of the working fluid mainly releases heat and condenses. The condensation region CR may be a region surrounding the evaporation region SR. In the condensation region CR, heat from the working vapor 2a is released to the upper sheet 20, and the working vapor 2a is cooled and condensed in the condensation region CR.

[0048] When the vapor chamber 1 is installed inside a mobile terminal, the up-down relationship may be lost depending on the orientation of the mobile terminal. However, in this embodiment, for convenience, the sheet that receives heat from the electronic device D will be referred to as the lower sheet 10, and the sheet that dissipates the received heat will be referred to as the upper sheet 20. For this reason, the following description will be given assuming that the lower sheet 10 is positioned on the lower side and the upper sheet 20 is positioned on the upper side.

[0049] As shown in FIG. 3, the lower sheet 10 is an example of a first sheet. The lower sheet 10 has a first lower sheet surface 10a provided on the opposite side to the wick sheet 30 and a second lower sheet surface 10b provided on the opposite side to the first lower sheet surface 10a. The second lower sheet surface 10b is located on the wick sheet 30 side. In this embodiment, the second lower sheet surface 10b contacts a first main body surface 30a of the wick sheet 30, which will be described later. As shown in FIG. 4, alignment holes 12 may be provided at the four corners of the lower sheet 10. The above-mentioned electronic device D may be attached to the first lower sheet surface 10a.

[0050] As shown in FIG. 3, the upper sheet 20 is an example of the second sheet. The upper sheet 20 has a first upper sheet surface 20a provided on the wick sheet 30 side and a second upper sheet surface 20b provided on the opposite side to the first upper sheet surface 20a. In this embodiment, the first upper sheet surface 20a contacts a second main body surface 30b of the wick sheet 30, which will be described later. As shown in FIG. 5, alignment holes 22 may be provided at the four corners of the upper sheet 20. A housing member Ha that forms part of the housing H described above may be attached to the second upper sheet surface 20b. The entire second upper sheet surface 20b may be covered with the housing member Ha.

[0051] As shown in Fig. 3, the wick sheet 30 is an example of a main body sheet. The wick sheet 30 has a first main body surface 30a and a second main body surface 30b provided on the opposite side of the first main body surface 30a. The first main body surface 30a is disposed on the side of the lower sheet 10, and the lower sheet 10 is provided on the first main body surface 30a. The second main body surface 30b is disposed on the side of the upper sheet 20, and the upper sheet 20 is provided on the second main body surface 30b.

[0052] The second lower sheet surface 10b of the lower sheet 10 and the first main body surface 30a of the wick sheet 30 may be permanently bonded to each other by diffusion bonding. Similarly, the first upper sheet surface 20a of the upper sheet 20 and the second main body surface 30b of the wick sheet 30 may be permanently bonded to each other by diffusion bonding. The lower sheet 10, the upper sheet 20, and the wick sheet 30 may be bonded by other methods, such as brazing, as long as they are permanently bonded, rather than by diffusion bonding. The term "permanently bonded" is not limited to a strict meaning and may be used to mean that the bond between the lower sheet 10 and the wick sheet 30 can be maintained to an extent that the hermeticity of the sealed space 3 can be maintained during operation of the vapor chamber 1. The term "permanently bonded" may also be used to mean that the bond between the upper sheet 20 and the wick sheet 30 can be maintained to an extent that the bond between them can be maintained.

[0053] As shown in FIGS. 3, 6, and 7, the wick sheet 30 according to this embodiment includes a frame 32 formed in a rectangular frame shape in a plan view and a plurality of land portions 33 provided within the frame 32. The frame 32 and each land portion 33 extend from the first main body surface 30a to the second main body surface 30b. The frame 32 and each land portion 33 are portions of the wick sheet 30 that are not etched in the etching process described below, and the material of the wick sheet 30 remains. In this embodiment, the frame 32 is formed in a rectangular frame shape in a plan view. A steam flow path 50 is defined inside the frame 32. The steam flow path 50 is disposed inside the frame 32 around each land portion 33. The working steam 2a flows around each land portion 33. The steam flow path 50 is defined between the frame 32 and the land portion 33, and also between a pair of adjacent land portions 33.

[0054] In this embodiment, the land portion 33 may extend in an elongated shape with the X direction as the longitudinal direction in a plan view. The planar shape of the land portion 33 may be an elongated rectangular shape. The land portions 33 may be arranged parallel to one another and spaced at equal intervals in the Y direction. The working steam 2a flows around each land portion 33 and is transported toward the condensation region CR. This prevents the flow of the working steam 2a from being obstructed. In this embodiment, the X direction is an example of a first direction and corresponds to the left-right direction in FIG. 6. The Y direction is an example of a second direction and corresponds to the up-down direction in FIG. 6. The X direction is the longitudinal direction of the land portion 33, and the Y direction is a direction perpendicular to the X direction in a plan view. The directions perpendicular to the X direction and the Y direction are respectively referred to as Z directions.

[0055] The width w1 of the land portion 33 (see FIG. 8A) may be, for example, 100 μm to 3000 μm. Here, the width w1 of the land portion 33 is the dimension of the land portion 33 in the Y direction. To explain this in more detail using wall surface protrusions 57 and 58 described below, the width w1 of the land portion 33 means the distance in the Y direction between the tip of the first wall surface protrusion 57 and the tip of the second wall surface protrusion 58 that define the land portion 33.

[0056] The frame body 32 and each land portion 33 are diffusion bonded to the lower sheet 10 and also to the upper sheet 20. This improves the mechanical strength of the vapor chamber 1. Lower wall surfaces 53a, 53b of the lower vapor flow path recess 53 and upper wall surfaces 54a, 54b of the upper vapor flow path recess 54, which will be described later, form the side walls of the land portion 33. The first main body surface 30a and the second main body surface 30b of the wick sheet 30 may be formed flat across the frame body 32 and each land portion 33.

[0057] The vapor flow path portion 50 is an example of a through space. The vapor flow path portion 50 may be provided on the first main body surface 30a of the wick sheet 30. The vapor flow path portion 50 may be a flow path through which the working vapor 2a mainly passes. The working fluid 2b may also pass through the vapor flow path portion 50. In this embodiment, the vapor flow path portion 50 extends from the first main body surface 30a to the second main body surface 30b and penetrates the wick sheet 30. The vapor flow path portion 50 may be covered by the lower sheet 10 on the first main body surface 30a, and may be covered by the upper sheet 20 on the second main body surface 30b.

[0058] As shown in FIGS. 6 and 7 , the steam flow path section 50 in this embodiment has a first steam path 51 and a plurality of second steam paths 52. The first steam path 51 includes a portion extending in the X direction and a portion extending in the Y direction in a plan view, and is formed between the frame body section 32 and the land section 33. The first steam path 51 is formed inside the frame body section 32 and continuously outside the land section 33. The first steam path 51 has a rectangular frame shape in plan view. The second steam path 52 extends in the X direction in a plan view and is formed between adjacent land sections 33. The second steam path 52 has an elongated rectangular shape in plan view. The steam flow path section 50 is partitioned into the first steam path 51 and the plurality of second steam paths 52 by the plurality of lands 33.

[0059] As shown in FIG. 8A , the first steam passage 51 and the second steam passage 52 extend from the first body surface 30a to the second body surface 30b of the wick sheet 30. The first steam passage 51 and the second steam passage 52 each have a lower steam flow path recess 53, an upper steam flow path recess 54, a lower opening 55, and an upper opening 56. The lower steam flow path recess 53 is an example of a first spatial recess and is provided in the first body surface 30a. The upper steam flow path recess 54 is an example of a second spatial recess and is provided in the second body surface 30b. The lower steam flow path recess 53 and the upper steam flow path recess 54 are connected to each other, so that the first steam passage 51 and the second steam passage 52 of the steam flow path section 50 extend from the first body surface 30a to the second body surface 30b. The lower opening 55 is an example of a first opening and is located in the first body surface 30a. The lower opening 55 is defined by a lower steam flow path recess 53 in the first body surface 30a. The upper opening 56 is an example of a second opening and is located in the second body surface 30b. The upper opening 56 is defined by an upper steam flow path recess 54 in the second body surface 30b.

[0060] The lower steam flow path recess 53 is formed in a concave shape on the first main body surface 30a by etching the first main body surface 30a of the wick sheet 30 in an etching step described below. As a result, the lower steam flow path recess 53 has a pair of lower wall surfaces 53a, 53b formed in a curved shape, as shown in FIG. 8A. The lower wall surfaces 53a, 53b are an example of a first wall surface. The lower wall surface 53a is the wall surface on the left side in FIG. 8A, and the lower wall surface 53b is the wall surface on the right side in FIG. 8A. The lower wall surfaces 53a, 53b are formed to extend from the lower opening 55 toward the second main body surface 30b. The lower wall surfaces 53a, 53b may be curved in a concave shape. Each lower wall surface 53a, 53b defines a lower steam flow path recess 53, and may be curved so as to approach the opposing lower wall surface 53a, 53b as it approaches the second main body surface 30b in the cross section shown in Figure 8A. Such lower steam flow path recess 53 constitutes a part of the first steam passage 51 and a part of the second steam passage 52. The lower steam flow path recess 53 may constitute the lower half of the first steam passage 51 and the lower half of the second steam passage 52.

[0061] The width w2 of the lower opening 55 may be, for example, 100 μm to 3000 μm. The width w2 of the lower opening 55 refers to the width dimension of the lower steam channel recess 53 at the first main body surface 30a. The width w2 corresponds to the Y-direction dimension of the portion of the first steam channel 51 extending in the X-direction and also corresponds to the Y-direction dimension of the second steam channel 52. In this embodiment, the Y-direction dimension between the lower wall surface 53a and the lower wall surface 53b of the lower steam channel recess 53 gradually increases from the second main body surface 30b toward the first main body surface 30a and is greatest at the first main body surface 30a. Therefore, the width w2 is the maximum value of the Y-direction dimension between the lower wall surface 53a and the lower wall surface 53b. However, the Y-direction dimension between the lower wall surface 53a and the lower wall surface 53b does not have to be greatest at the first main body surface 30a. For example, the position where the dimension in the Y direction between the lower wall surface 53a and the lower wall surface 53b is maximum may be located closer to the second main body surface 30b than to the first main body surface 30a. The width w2 also corresponds to the dimension in the X direction of the portion of the first steam passage 51 extending in the Y direction.

[0062] The upper steam flow path recess 54 is formed in a concave shape on the second main body surface 30b by etching the second main body surface 30b of the wick sheet 30 in an etching process described below. As a result, the upper steam flow path recess 54 has a pair of upper wall surfaces 54a, 54b formed in a curved shape, as shown in FIG. 8A. The upper wall surfaces 54a, 54b are an example of second wall surfaces. The upper wall surface 54a is the wall surface on the left side in FIG. 8A, and the upper wall surface 54b is the wall surface on the right side in FIG. 8A. The upper wall surfaces 54a, 54b are formed to extend from the upper opening 56 toward the first main body surface 30a. The upper wall surfaces 54a, 54b may be curved in a concave shape. Each upper wall surface 54a, 54b defines an upper steam flow path recess 54, and may curve toward the opposing upper wall surface 54a, 54b as it approaches first body surface 30a in the cross section shown in Figure 8A. Such upper steam flow path recess 54 forms part of first steam passage 51 and part of second steam passage 52. Upper steam flow path recess 54 may form the upper half of first steam passage 51 and the upper half of second steam passage 52.

[0063] The width w3 of the upper opening 56 may be larger than the width w2 of the lower opening 55. The width w3 may be, for example, 160 μm to 5800 μm. The width w3 of the upper opening 56 refers to the width dimension of the upper steam channel recess 54 at the second main body surface 30b. The width w3 corresponds to the Y-direction dimension of the portion of the first steam channel 51 extending in the X-direction and the Y-direction dimension of the second steam channel 52. In this embodiment, the Y-direction dimension between the upper wall surface 54a and the upper wall surface 54b gradually increases from the first main body surface 30a toward the second main body surface 30b and is greatest at the second main body surface 30b. Therefore, the width w3 is the maximum value of the Y-direction dimension between the upper wall surface 54a and the upper wall surface 54b. However, the Y-direction dimension between the upper wall surface 54a and the upper wall surface 54b does not have to be greatest at the second main body surface 30b. For example, the position where the dimension in the Y direction between the upper wall surface 54a and the upper wall surface 54b is maximum may be located closer to the first main body surface 30a than to the second main body surface 30b. The width w3 also corresponds to the dimension in the X direction of the portion of the first steam passage 51 extending in the Y direction.

[0064] 8A , in a plan view, the center 55a of the lower opening 55 may overlap the center 56a of the upper opening 56. Alternatively, the center 55a of the lower opening 55 may be shifted from the center 56a of the upper opening 56.

[0065] The lower opening 55 may be defined by a pair of lower opening side edges 55b extending in the X direction. The lower opening side edges 55b are an example of first opening side edges. The center 55a of the lower opening 55 described above may be the midpoint of the pair of lower opening side edges 55b when viewed in a cross section perpendicular to the X direction. In FIG. 8A , the lower opening side edges 55b are shown as the intersections of the first main body surface 30a and the lower wall surfaces 53a, 53b, and the midpoint of these intersections may be the center 55a of the lower opening 55.

[0066] The upper opening 56 may be defined by a pair of upper opening side edges 56b extending in the X direction. The upper opening side edges 56b are an example of second opening side edges. The center 56a of the upper opening 56 described above may be the midpoint of the pair of upper opening side edges 56b when viewed in a cross section perpendicular to the X direction. In FIG. 8A , the upper opening side edges 56b are shown as the intersections of the second main body surface 30b and the upper wall surfaces 54a, 54b, and the midpoint of these intersections may be the center 56a of the upper opening 56.

[0067] As described above, the width w3 of the upper opening 56 may be larger than the width w2 of the lower opening 55. The upper opening 56 may extend from a region 56c that overlaps with the lower opening 55 in a plan view to a position that overlaps with a main stream groove 61 (described later) in a plan view. This allows the flow path cross-sectional area of ​​the upper steam flow path recess 54 to be larger than that of the lower steam flow path recess 53. Here, as shown in FIG. 8A , an intersection point P1 is defined as a line extending in the Z direction through the second wall surface protrusion 58 and intersects with the second lower seat surface 10b. A region defined by the intersection point P1, the lower opening side edge 55b, the lower wall surface 53b, and the second wall surface protrusion 58 is defined as a lower steam flow path partial region. A point P2 is defined as an intersection point P2 where a line extending in the Z direction through the second wall surface protrusion 58 intersects with the first upper seat surface 20a. The region defined by the intersection point P2, the upper opening side edge 56b, the upper wall surface 54b, and the second wall surface protrusion 58 is defined as the upper vapor flow path region. Because the upper vapor flow path region has a larger flow path cross-sectional area than the lower vapor flow path region, the capillary action in the upper vapor flow path region is smaller than that in the lower vapor flow path region. Therefore, the upper vapor flow path region can reduce the flow resistance of the working vapor 2a in the upper vapor flow path region, facilitating diffusion of the working vapor 2a and improving heat dissipation efficiency. The same is true for the region defined by the lower wall surface 53a and the upper wall surface 54a. Meanwhile, a land portion 33 bonded to the upper sheet 20 is formed between adjacent upper openings 56 in the Y direction. This ensures the mechanical strength of the vapor chamber 1. In this way, the vapor chamber 1 according to this embodiment effectively utilizes limited space, ensures mechanical strength, and improves heat dissipation efficiency.

[0068] A portion of the upper opening 56 may overlap, in plan view, a portion of the main groove 61 adjacent to the steam passages 51, 52. A portion of the upper opening 56 may overlap, in plan view, a plurality of main grooves 61. The number of main grooves 61 that the upper opening 56 overlaps is arbitrary.

[0069] An example of the positional relationship between the upper openings 56 and the main stream grooves 61 will be described with reference to FIGS. 8B to 8E . Here, the main stream groove 61 adjacent to the second steam passage 52 formed by one upper opening 56 will be referred to as a main stream groove 61P, and the other main stream groove 61 adjacent to the main stream groove 61P will be referred to as a main stream groove 61Q. The main stream groove 61Q is located farther from the center 55a of the lower openings 55 than the main stream groove 61P. In other words, the main stream groove 61Q is located farther from the center 56a of the upper openings 56 than the main stream groove 61P. In this embodiment, in a plan view, the center 55a of the lower openings 55 overlaps the center 56a of the upper openings 56. Hereinafter, the positional relationship between the upper openings 56 and the main stream grooves 61 will be described using the center 55a of the lower openings 55.

[0070] The main grooves 61P, 61Q include a first main groove side edge 61a and a second main groove side edge 61b that extend in the X direction. In Figures 8B to 8E, the first main groove side edge 61a and the second main groove side edge 61b are shown as intersections of the first main body surface 30a and a wall surface 62 (described later). The first main groove side edge 61a is located closer to the center 55a of the lower opening 55 than the second main groove side edge 61b, and the second main groove side edge 61b is located farther from the center 55a of the lower opening 55 than the first main groove side edge 61a.

[0071] 8B , the upper opening 56 may extend in the Y direction to a position overlapping with a part of the main groove 61P. In this case, the upper opening side edge 56b may be located closer to the center 55a of the lower opening 55 than the second main groove side edge 61b of the main groove 61P in a plan view.

[0072] 8C , the upper opening 56 may extend in the Y direction to a position overlapping the entire main stream groove 61P adjacent to the second steam passage 52. In this case, the upper opening side edge 56b may be located at a position overlapping the second main stream groove side edge 61b of the main stream groove 61P in plan view, or may be located farther from the center 55a of the lower opening 55 than the second main stream groove side edge 61b of the main stream groove 61P. Alternatively, the upper opening side edge 56b may be located at a position overlapping the first main stream groove side edge 61a of the main stream groove 61Q in plan view.

[0073] 8D , the upper opening 56 may extend in the Y direction to a position overlapping a part of the main groove 61Q. In this case, the upper opening side edge 56b may be located farther from the center 55a of the lower opening 55 than the first main groove side edge 61a of the main groove 61Q in a plan view, or may be located closer to the center 55a of the lower opening 55 than the second main groove side edge 61b of the main groove 61Q.

[0074] 8E, the upper opening 56 may extend in the Y direction to a position overlapping the entire main groove 61Q. In this case, the upper opening side edge 56b may be located at a position overlapping the second main groove side edge 61b of the main groove 61Q in plan view, or may be located farther from the center 55a of the lower opening 55 than the second main groove side edge 61b of the main groove 61Q.

[0075] The above has described an example of the positional relationship between the upper opening 56 and the mainstream groove 61 adjacent to the second steam passage 52 formed by the upper opening 56. The same applies to the positional relationship between the upper opening 56 and the mainstream groove 61 adjacent to the first steam passage 51 formed by the upper opening 56.

[0076] 10 , when viewed in a cross section perpendicular to the X direction, the upper opening 56 of the first steam passage 51 may extend from a region 56c that overlaps with the lower opening 55 in a plan view toward the outside of the frame body 32 beyond the lower opening 55. The lower opening 55 and the upper opening 56 of the first steam passage 51 are located between the frame body 32 and the land portion 33 adjacent to the frame body 32. Here, the upper opening 56 in the portion of the first steam passage 51 extending in the X direction will be described. Similarly, in the portion of the first steam passage 51 extending in the Y direction, the width of the upper opening 56 may be larger than the width of the lower opening 55.

[0077] A more specific explanation will be given. The pair of lower opening edges 55b described above is assumed to be composed of a first lower opening edge 55ba and a second lower opening edge 55bb. The first lower opening edge 55ba defines the boundary between the frame body 32 and the lower opening 55, and the second lower opening edge 55bb defines the boundary between the land portion 33 and the lower opening 55. The pair of upper opening edges 56b described above is assumed to be composed of a first upper opening edge 56ba and a second upper opening edge 56bb. The first upper opening edge 56ba defines the boundary between the frame body 32 and the upper opening 56, and the second upper opening edge 56bb defines the boundary between the land portion 33 and the upper opening 56.

[0078] The first upper opening edge 56ba is located further outward from the first lower opening edge 55ba of the frame portion 32. In the example shown in Fig. 10, the first upper opening edge 56ba is located to the left of the first lower opening edge 55ba.

[0079] When viewed in a cross section perpendicular to the X direction, the upper opening 56 of the first steam passage 51 may extend from a region 56c overlapping with the lower opening 55 in a plan view to a position overlapping with the main flow path groove 61 located in the land portion 33 in a plan view. The second upper opening side edge 56bb is located at a position overlapping with the liquid flow path portion 60 located in the land portion 33. In the example shown in Fig. 10, the second upper opening side edge 56bb is located to the right of the second lower opening side edge 55bb.

[0080] 8A , when viewed in a cross section perpendicular to the X direction, the upper opening 56 of the second steam passage 52 may extend from a region 56c overlapping with the lower opening 55 in a plan view to a position overlapping with the mainstream groove 61 located in the land portion 33 in a plan view. The upper opening 56 of the second steam passage 52 may extend from the region 56c overlapping with the lower opening 55 in a plan view to positions overlapping with the mainstream groove 61 in a plan view on both sides of the lower opening 55.

[0081] More specifically, it is assumed here that the second steam passage 52 is located between the first land portion 33P and the second land portion 33Q that are adjacent to each other. The lower opening 55 and the upper opening 56 are located between the first land portion 33P and the second land portion 33Q.

[0082] When viewed in a cross section perpendicular to the X direction, the upper opening 56 of the second steam passage 52 may extend from a position overlapping the mainstream groove 61 located in the first land portion 33P in a plan view to a position overlapping the mainstream groove 61 located in the second land portion 33Q in a plan view. Each upper opening edge 56b is located at a position overlapping the liquid flow path portion 60 of the corresponding land portion 33P, 33Q. In the example shown in FIG. 8A , the left upper opening edge 56b is located to the left of the left lower opening edge 55b. The right upper opening edge 56b is located to the right of the right lower opening edge 55b.

[0083] 8A, the distance from each wall protrusion 57, 58 to the corresponding upper opening side edge 56b is indicated by w12. w12 may be, for example, 30 μm to 1400 μm. The distance w12 refers to the planar distance between the first wall protrusion 57 and the left upper opening side edge 56b, and also the planar distance between the second wall protrusion 58 and the right upper opening side edge 56b, when viewed in a cross section perpendicular to the X direction. The distance w12 corresponds to the dimension in the Y direction.

[0084] 8A, the width of the land portion 33 on the second main body surface 30b is indicated by w13. w13 may be, for example, 30 μm to 2900 μm. The width w13 refers to the distance from an upper opening side edge 56b that defines one upper opening 56 to an upper opening side edge 56b that defines the other upper opening 56 when viewed in a cross section perpendicular to the X direction. The width w13 corresponds to the dimension in the Y direction.

[0085] 8A , the lower wall surfaces 53a, 53b of the lower steam flow path recess 53 and the corresponding upper wall surfaces 54a, 54b of the upper steam flow path recess 54 are connected by wall surface protrusions 57, 58. More specifically, the lower wall surface 53a of the lower steam flow path recess 53 and the corresponding upper wall surface 54a of the upper steam flow path recess 54 are connected by a first wall surface protrusion 57. The lower wall surface 53b of the lower steam flow path recess 53 and the corresponding upper wall surface 54b of the upper steam flow path recess 54 are connected by a second wall surface protrusion 58. The first wall surface protrusion 57 is the wall surface protrusion on the left side in FIG. 8A , and the second wall surface protrusion 58 is the wall surface protrusion on the right side in FIG. 8A .

[0086] 8A, the first wall surface protrusion 57 may protrude toward the inside of the steam passages 51, 52. The second wall surface protrusion 58 may protrude toward the inside of the steam passages 51, 52. In this embodiment, the pair of wall surface protrusions 57, 58 protrude toward each other in directions along the first main body surface 30a and the second main body surface 30b.

[0087] In this embodiment, the first wall surface protrusion 57 is disposed at an intermediate position MP between the first main body surface 30a and the second main body surface 30b in the Z direction. However, this is not limited to this, and the first wall surface protrusion 57 may be disposed offset from the intermediate position MP. In the example shown in FIG. 8A , the first wall surface protrusion 57 is disposed at the same position as the second wall surface protrusion 58 in the Z direction. However, this is not limited to this, and the first wall surface protrusion 57 may be disposed offset from the second wall surface protrusion 58 in the Z direction.

[0088] Similarly, in this embodiment, the second wall surface protrusion 58 is disposed at an intermediate position MP between the first main body surface 30a and the second main body surface 30b in the Z direction. However, this is not limited to this, and the second wall surface protrusion 58 may be disposed offset from the intermediate position MP. In the example shown in FIG. 8A , the second wall surface protrusion 58 is disposed at the same position as the first wall surface protrusion 57 in the Z direction. However, this is not limited to this, and the second wall surface protrusion 58 may be disposed offset from the first wall surface protrusion 57 in the Z direction.

[0089] A pair of wall surface protrusions 57, 58 defines a through portion 34, and the lower steam flow path recess 53 and the upper steam flow path recess 54 communicate with each other in the through portion 34. In this embodiment, the planar shape of the through portion 34 in the first steam passage 51 is a rectangular frame shape, similar to the first steam passage 51. The planar shape of the through portion 34 in the second steam passage 52 is an elongated rectangular shape, similar to the second steam passage 52. The width w4 of such a through portion 34 (see FIG. 8A ) may be, for example, 200 μm to 500 μm. Here, the width w4 of the through portion 34 corresponds to the gap between the land portions 33 adjacent to each other in the Y direction. More specifically, the width w4 means the distance in the Y direction between the tip of the first wall surface protrusion 57 and the tip of the second wall surface protrusion 58 that define the through portion 34.

[0090] When viewed in a cross section perpendicular to the X direction, the upper steam flow path recess 54 may include two flat surfaces 59a, 59b. Each flat surface 59a, 59b connects the corresponding upper wall surface 54a, 54b to the wall surface protrusions 57, 58. The flat surface 59a is the left surface in FIG. 8A , and the flat surface 59b is the right surface in FIG. 8A . More specifically, the upper wall surface 54a is connected to the first wall surface protrusion 57 via one flat surface 59a, and the flat surface 59a is formed between the upper wall surface 54a and the first wall surface protrusion 57. The upper wall surface 54b is connected to the second wall surface protrusion 58 via the other flat surface 59b, and the flat surface 59b is formed between the upper wall surface 54b and the second wall surface protrusion 58. The flat surfaces 59a, 59b may be aligned with the second body surface 30b when viewed in a cross section perpendicular to the X direction. In this case, the flat surfaces 59a, 59b may be parallel to the second body surface 30b or parallel to the first body surface 30a. However, the flat surfaces 59a, 59b may be inclined with respect to the second body surface 30b. The two flat surfaces 59a, 59b may both be aligned with the second body surface 30b, or both may be inclined with respect to the second body surface 30b. Alternatively, one of the two flat surfaces 59a, 59b may be aligned with the second body surface 30b, and the other may be inclined with respect to the second body surface 30b.

[0091] The flat surfaces 59a, 59b may be formed flat. For example, the flat surfaces 59a, 59b may be formed so that, when viewed in a cross section perpendicular to the X direction, the difference between the flat surfaces 59a, 59b is within a range of less than 3 μm in a direction perpendicular to the flat surfaces 59a, 59b. For example, when viewed in a cross section perpendicular to the X direction, the difference between the flat surfaces 59a, 59b is within a range of less than 3 μm in a direction perpendicular to a reference line connecting the wall surface protrusions 57, 58 and the end points of the upper wall surfaces 54a, 54b.

[0092] 8F, flat surfaces 59a and 59b will be described in more detail. Here, for clarity of explanation, flat surface 59b will be described as a representative. As flat surface 59a is similar to flat surface 59b, detailed explanation thereof will be omitted.

[0093] As shown in FIG. 8F , a reference line corresponding to flat surface 59b is indicated by a line labeled 59c. Reference line 59c may be a straight line connecting second wall surface protrusion 58 and end point 54c of upper wall surface 54b. End point 54c may be a point on upper wall surface 54b that is closest to second wall surface protrusion 58. Flat surface 59b may be formed within range 59f between first boundary line 59d and second boundary line 59e. First boundary line 59d may be a line that is shifted from reference line 59c in a direction toward first main body surface 30a and is parallel to reference line 59c. Second boundary line 59e may be a line that is shifted from reference line 59c in a direction toward second main body surface 30b and is parallel to reference line 59c. Flat surface 59b may be formed within range 59f between first boundary line 59d and second boundary line 59e defined in this manner.

[0094] As shown in Fig. 8F, the reference line 59c may be aligned with the second body surface 30b. In this case, the first boundary line 59d and the second boundary line 59e may also be aligned with the second body surface 30b. However, this is not limited thereto, and the reference line 59c may be inclined with respect to the second body surface 30b. In this case, the first boundary line 59d and the second boundary line 59e may also be inclined with respect to the second body surface 30b.

[0095] As shown in FIG. 8F , the distance between the first boundary line 59d and the reference line 59c and the distance between the second boundary line 59e and the reference line 59c may be equal. In this case, for example, the distance between the first boundary line 59d and the reference line 59c may be less than 1.5 μm. For example, the distance between the second boundary line 59e and the reference line 59c may be less than 1.5 μm. However, the distance between the first boundary line 59d and the reference line 59c and the distance between the second boundary line 59e and the reference line 59c are not limited to being equal. As long as the distance between the first boundary line 59d and the second boundary line 59e is less than 3.0 μm, the distance between the first boundary line 59d and the reference line 59c and the distance between the second boundary line 59e and the reference line 59c may be different. The first boundary line 59d may overlap the reference line 59c, or the second boundary line 59e may overlap the reference line 59c.

[0096] 8A, the depth of the upper steam flow path recess 54 is indicated by h2. h2 may be, for example, 20 μm to 250 μm. The depth h2 refers to the distance from the second main body surface 30b to the flat surfaces 59a, 59b when viewed in a cross section perpendicular to the X direction. The depth h2 corresponds to the dimension in the Z direction.

[0097] The width w3 of the upper opening 56 may be larger than the width w2 of the lower opening 55 over the entire region in the X direction of the land portion 33. This allows the flow path cross-sectional area of ​​the steam passages 51, 52 to be increased over the entire region in the X direction of the land portion 33.

[0098] The steam flow path section 50 including the first steam path 51 and the second steam path 52 configured in this manner constitutes a part of the above-mentioned sealed space 3. As shown in Fig. 3, the steam flow path section 50 according to this embodiment is defined mainly by the lower sheet 10, the upper sheet 20, and the frame portion 32 and land portion 33 of the above-mentioned wick sheet 30. Each of the steam paths 51, 52 has a relatively large flow path cross-sectional area to allow the working steam 2a to pass through.

[0099] Here, in order to clarify the drawing, FIG. 3 shows the first steam passage 51, the second steam passage 52, etc. in an enlarged manner, and the number and arrangement of these steam passages 51, 52, etc. are different from those in FIGS. 2, 6, and 7.

[0100] Although not shown, multiple support portions for supporting the land portion 33 on the frame portion 32 may be provided within the vapor flow path portion 50. Support portions for supporting adjacent land portions 33 may also be provided. These support portions may be provided on both sides of the land portion 33 in the X direction or on both sides of the land portion 33 in the Y direction. The support portions may be formed so as not to interfere with the flow of the working vapor 2a diffusing through the vapor flow path portion 50. For example, the support portions may be disposed on one side of the first main body surface 30a or the second main body surface 30b of the wick sheet 30, with a space forming the vapor flow path formed on the other side. This allows the thickness of the support portions to be thinner than the thickness of the wick sheet 30, preventing the first vapor path 51 and the second vapor path 52 from being separated in the X direction and the Y direction.

[0101] As shown in FIGS. 6 and 7, the wick sheet 30 may have alignment holes 35 at its four corners, similar to the lower sheet 10 and the upper sheet 20. As shown in FIGS.

[0102] As shown in Fig. 2, the vapor chamber 1 may further include an injection part 4 at one edge in the X direction, which injects the working fluid 2b into the sealed space 3. In the embodiment shown in Fig. 2, the injection part 4 is disposed on the evaporation region SR side and protrudes from the edge on the evaporation region SR side to the outside of the vapor chamber 1. Note that the injection part 4 does not have to protrude to the outside of the vapor chamber 1, as shown in Fig. 36 etc., which will be described later.

[0103] More specifically, the injection section 4 may have a lower injection protrusion 11 (see FIG. 4), an upper injection protrusion 21 (see FIG. 5), and a wick sheet injection protrusion 36 (see FIGS. 6 and 7). The lower injection protrusion 11 constitutes the lower sheet 10. The upper injection protrusion 21 constitutes the upper sheet 20. The wick sheet injection protrusion 36 constitutes the wick sheet 30. An injection flow path 37 is formed in the wick sheet injection protrusion 36. The injection flow path 37 may extend from the first main body surface 30a to the second main body surface 30b of the wick sheet 30, or may penetrate the wick sheet injection protrusion 36 of the wick sheet 30 in the Z direction. The injection flow path 37 is also connected to the vapor flow path section 50, and the working fluid 2b is injected into the sealed space 3 through the injection flow path 37. Depending on the arrangement of the liquid flow path section 60, the injection flow path 37 may be connected to the liquid flow path section 60. The upper and lower surfaces of the wick sheet injection protrusion 36 may be formed generally flat, and the upper surface of the lower injection protrusion 11 and the lower surface of the upper injection protrusion 21 may also be formed generally flat. The planar shapes of the injection protrusions 11, 21, and 36 may be the same.

[0104] In this embodiment, the injection portion 4 is provided on one edge of a pair of edges in the X direction of the vapor chamber 1, but this is not limited thereto and the injection portion 4 can be provided at any position. Furthermore, the injection flow path 37 provided in the wick sheet injection protrusion 36 does not have to penetrate the wick sheet injection protrusion 36 as long as it can inject the working fluid 2b. In this case, the injection flow path 37 communicating with the vapor flow path portion 50 can be configured by a recess formed in one of the first main body surface 30a and the second main body surface 30b of the wick sheet 30.

[0105] As shown in FIGS. 3, 8A, and 10, the liquid flow path portion 60 may be provided between the lower sheet 10 and the wick sheet 30. In this embodiment, the liquid flow path portion 60 is provided on the first main body surface 30a of the wick sheet 30. The liquid flow path portion 60 may be a flow path through which the working fluid 2b mainly passes. The working vapor 2a may also pass through the liquid flow path portion 60. The liquid flow path portion 60 constitutes a part of the sealed space 3 and communicates with the vapor flow path portion 50. The liquid flow path portion 60 is configured as a capillary structure (wick) for transporting the working fluid 2b to the evaporation region SR. In this embodiment, the liquid flow path portion 60 is provided on the first main body surface 30a of each land portion 33 of the wick sheet 30. The liquid flow path portion 60 may be formed over the entire first main body surface 30a of each land portion 33. Although not shown in FIG. 3 etc., the liquid flow path portion 60 may be provided on the second main body surface 30b of each land portion 33.

[0106] As shown in FIG. 9 , the liquid flow path section 60 is an example of a groove assembly including a plurality of grooves. More specifically, the liquid flow path section 60 has a plurality of mainstream grooves 61 through which the working fluid 2b passes, and a plurality of communication grooves 65 that communicate with the mainstream grooves 61. The mainstream grooves 61 of the liquid flow path section 60 are an example of first grooves. The communication grooves 65 of the liquid flow path section 60 are an example of second grooves. The mainstream grooves 61 and the communication grooves 65 are grooves through which the working fluid 2b passes. The communication grooves 65 communicate with the mainstream grooves 61.

[0107] As shown in Fig. 9, each mainstream groove 61 is formed to extend in the X direction. The mainstream groove 61 has a smaller flow path cross-sectional area than the first vapor passage 51 or the second vapor passage 52 of the vapor flow path section 50 so that the working fluid 2b flows mainly by capillary action. As a result, the mainstream groove 61 is configured to transport the working fluid 2b condensed from the working vapor 2a to the evaporation region SR. The mainstream grooves 61 may be arranged at equal intervals along the Y direction, which is perpendicular to the X direction.

[0108] The main grooves 61 are formed by etching from the first main body surface 30a of the wick sheet 30 in an etching process described below. As a result, the main grooves 61 have curved wall surfaces 62, as shown in Fig. 8A. These wall surfaces 62 define the main grooves 61 and are curved in a shape that bulges toward the second main body surface 30b.

[0109] 8A and 9, the width w5 (dimension in the Y direction) of the main groove 61 may be, for example, 5 μm to 400 μm. Note that the width w5 of the main groove 61 refers to the dimension at the first main body surface 30a. Also, as shown in FIG. 8A, the depth h1 (dimension in the Z direction) of the main groove 61 may be, for example, 5 μm to 100 μm.

[0110] As shown in FIG. 9 , each communication groove 65 extends in a direction different from the X direction. In this embodiment, each communication groove 65 is formed to extend in the Y direction, perpendicular to the mainstream grooves 61. Some communication grooves 65 are arranged to connect adjacent mainstream grooves 61 to each other. Other communication grooves 65 are arranged to connect the steam flow path section 50 (the first steam passage 51 or the second steam passage 52) to the mainstream groove 61. That is, the communication groove 65 extends from the side edge 33 a of the land portion 33 in the Y direction to the mainstream groove 61 adjacent to the side edge 33 a. In this way, the first steam passage 51 or the second steam passage 52 of the steam flow path section 50 and the mainstream groove 61 are connected to each other.

[0111] The communication groove 65 has a smaller flow path cross-sectional area than the first steam passage 51 or the second steam passage 52 of the steam flow path section 50 so that the working fluid 2b flows mainly by capillary action. The communication grooves 65 may be arranged at equal intervals along the X direction.

[0112] Like the mainstream groove 61, the communication groove 65 is also formed by etching, and has wall surfaces (not shown) that are formed in a curved shape similar to that of the mainstream groove 61. As shown in Fig. 9, the width w6 (dimension in the X direction) of the communication groove 65 may be equal to the width w5 of the mainstream groove 61, or may be greater or smaller than the width w5. The depth of the communication groove 65 may be equal to the depth h1 of the mainstream groove 61, or may be greater or shallower than the depth h1.

[0113] As shown in FIG. 9 , the liquid flow path section 60 has a convex portion row 63 provided on the first main body surface 30a of the wick sheet 30. The convex portion row 63 is provided between adjacent main flow path grooves 61. Each convex portion row 63 includes a plurality of convex portions 64 (an example of a liquid flow path protrusion) arranged in the X direction. The convex portions 64 are provided within the liquid flow path section 60 and abut against the upper sheet 20. Each convex portion 64 is formed in a rectangular shape with the X direction as its longitudinal direction in a plan view. A main flow path groove 61 is interposed between adjacent convex portions 64 in the Y direction, and a communication groove 65 is interposed between adjacent convex portions 64 in the X direction. The communication groove 65 is formed to extend in the Y direction and connects adjacent main flow path grooves 61 in the Y direction. This allows the working fluid 2b to move back and forth between these main flow path grooves 61.

[0114] The protrusions 64 are portions that are not etched in the etching process described below, and remain as the material of the wick sheet 30. In this embodiment, as shown in Fig. 9, the planar shape of the protrusions 64 is the shape at the position of the first main body surface 30a of the wick sheet 30, but is rectangular.

[0115] In this embodiment, the protrusions 64 are arranged in a staggered pattern. More specifically, the protrusions 64 of the protrusion rows 63 adjacent to each other in the Y direction are arranged so as to be shifted from each other in the X direction. This shift amount may be half the arrangement pitch of the protrusions 64 in the X direction. The width w7 (dimension in the Y direction) of the protrusions 64 may be, for example, 5 μm to 500 μm. Note that the width w7 of the protrusions 64 refers to the dimension on the first main body surface 30a. Note that the arrangement of the protrusions 64 is not limited to a staggered pattern, and they may be arranged in parallel. In this case, the protrusions 64 of the protrusion rows 63 adjacent to each other in the Y direction are also aligned in the Y direction.

[0116] The main groove 61 includes an intersection 66 that communicates with the communication groove 65. At the intersection 66, the main groove 61 and the communication groove 65 communicate in a T-shape. This makes it possible to prevent the communication groove 65 on the other side (for example, the lower side in FIG. 9 ) from communicating with the main groove 61 at the intersection 66 where one main groove 61 communicates with the communication groove 65 on one side (for example, the upper side in FIG. 9 ).

[0117] That is, when the communication grooves 65 on both sides of one main groove 61 in the Y direction (both the upper and lower sides in FIG. 9) are positioned at the same position in the X direction, the main groove 61 and the communication groove 65 intersect in a cross shape. In this case, the wall surface 62 (see FIG. 8A) of the main groove 61 is cut out on both sides (the upper and lower sides in FIG. 9) by the communication groove 65 at the same position in the X direction. At this cut-out position, a continuous space is formed in a cross shape, which can reduce the capillary action of the main groove 61.

[0118] In contrast, according to the present embodiment, the communication grooves 65 present on both sides of one mainstream groove 61 in the Y direction (both the upper and lower sides in FIG. 9 ) are arranged at different positions in the X direction. This allows the position of the wall surface 62 of the mainstream groove 61 cut out by the communication groove 65 on one side in the Y direction to differ from the position of the wall surface 62 of the mainstream groove 61 cut out by the communication groove 65 on the other side in the Y direction in the X direction. In this case, the mainstream groove 61 communicates with the communication groove 65 on one side in the Y direction, so the wall surface 62 of the mainstream groove 61 remains on the other side in the Y direction. Therefore, at the position where the wall surface 62 of the mainstream groove 61 is cut out by the communication groove 65, a continuous space is formed in a T-shape, which prevents a decrease in the capillary action of the mainstream groove 61. This prevents a decrease in the propulsion force of the working fluid 2b toward the evaporation region SR at the intersection 66.

[0119] The materials constituting the lower sheet 10, the upper sheet 20, and the wick sheet 30 are not particularly limited as long as they have sufficient thermal conductivity to ensure the heat dissipation efficiency of the vapor chamber 1. For example, the materials for the sheets 10, 20, and 30 include copper or copper alloys, which have good thermal conductivity and corrosion resistance when using pure water as the working fluid. Examples of copper include pure copper and oxygen-free copper (C1020). Examples of copper alloys include copper alloys containing tin, copper alloys containing titanium (C1990, etc.), and Corson copper alloys (C7025, etc.), which are copper alloys containing nickel, silicon, and magnesium. An example of a copper alloy containing tin is phosphor bronze (C5210, etc.).

[0120] 3 may be, for example, 100 μm to 500 μm. By making the thickness t1 of the vapor chamber 1 100 μm or more, the vapor channel section 50 can be appropriately secured, allowing the vapor chamber 1 to function appropriately. On the other hand, by making the thickness t1 500 μm or less, the thickness t1 of the vapor chamber 1 can be prevented from becoming too thick.

[0121] The thickness of the wick sheet 30 may be thicker than the thickness of the lower sheet 10. Similarly, the thickness of the wick sheet 30 may be thicker than the thickness of the upper sheet 20. In this embodiment, an example is shown in which the thickness of the lower sheet 10 and the thickness of the upper sheet 20 are equal, but this is not limited to this, and the thickness of the lower sheet 10 and the thickness of the upper sheet 20 may be different.

[0122] The thickness t2 of the lower sheet 10 may be, for example, 6 μm to 100 μm. By setting the thickness t2 of the lower sheet 10 to 6 μm or more, the mechanical strength and long-term reliability of the lower sheet 10 can be ensured. On the other hand, by setting the thickness t2 of the lower sheet 10 to 100 μm or less, an increase in the thickness t1 of the vapor chamber 1 can be prevented. Similarly, the thickness t3 of the upper sheet 20 may be set to the same as the thickness t2 of the lower sheet 10.

[0123] The thickness t4 of the wick sheet 30 may be, for example, 50 μm to 300 μm. By making the thickness t4 of the wick sheet 30 50 μm or more, the vapor flow path portion 50 is properly secured, allowing the vapor chamber 1 to function properly. On the other hand, by making the thickness t4 300 μm or less, the thickness t1 of the vapor chamber 1 can be prevented from becoming too thick. The thickness t4 of the wick sheet 30 may be the distance between the first main body surface 30a and the second main body surface 30b.

[0124] The vapor chamber 1 according to this embodiment having such a configuration can be manufactured by referring to the manufacturing method described later with reference to Figures 18 to 23. The flat surfaces 59a, 59b of the upper vapor flow path recess 54 can be easily formed by adjusting etching conditions such as the shape of the resist, the flow of the etching solution, or the etching time.

[0125] Next, a method for operating the vapor chamber 1, that is, a method for cooling the electronic device D, will be described.

[0126] The vapor chamber 1 obtained as described above is installed in a housing H of a mobile terminal or the like, and the housing member Ha is attached to the second upper sheet surface 20b of the upper sheet 20. Alternatively, the vapor chamber 1 is attached to the housing member Ha. Furthermore, an electronic device D, such as a CPU, which is a device to be cooled, is attached to the first lower sheet surface 10a of the lower sheet 10. Alternatively, the vapor chamber 1 is attached to the electronic device D. The working fluid 2b in the sealed space 3 adheres to the wall surfaces of the sealed space 3 due to its surface tension. More specifically, the working fluid 2b adheres to the lower wall surfaces 53a, 53b of the lower vapor channel recess 53, the upper wall surfaces 54a, 54b of the upper vapor channel recess 54, the flat surfaces 59a, 59b, the wall surfaces 62 of the main channel groove 61, and the wall surfaces of the connecting groove 65. The working fluid 2b may also adhere to the portion of the second lower sheet surface 10b of the lower sheet 10 exposed to the lower vapor channel recess 53. The working fluid 2 b may also adhere to the portions of the first upper sheet surface 20 a of the upper sheet 20 that are exposed to the upper steam flow path recesses 54 , the main grooves 61 , and the communication grooves 65 .

[0127] In this state, when the electronic device D generates heat, the working liquid 2b present in the evaporation region SR (see FIGS. 6 and 7 ) receives heat from the electronic device D. The received heat is absorbed as latent heat, and the working liquid 2b evaporates (vaporizes), generating working vapor 2a. Most of the generated working vapor 2a diffuses within the first vapor passage 51 and the second vapor passage 52 that constitute the sealed space 3 (see the solid arrows in FIG. 7 ). More specifically, in the portion of the first vapor passage 51 extending in the X direction and the second vapor passage 52 of the vapor flow path section 50, the working vapor 2a diffuses mainly in the X direction. On the other hand, in the portion of the first vapor passage 51 extending in the Y direction, the working vapor 2a diffuses mainly in the Y direction. In this embodiment, the upper opening 56 is larger than the lower opening 55, thereby increasing the flow path cross-sectional areas of the vapor passages 51 and 52. This reduces the flow path resistance of the working vapor 2a, allowing the working vapor 2a to diffuse smoothly.

[0128] Then, the working steam 2a in each steam passage 51, 52 leaves the evaporation region SR, and most of the working steam 2a is transported to the condensation region CR (the right-hand portion in Figures 6 and 7) where the temperature is relatively low. In the condensation region CR, the working steam 2a is cooled by radiating heat mainly to the upper sheet 20. The heat received by the upper sheet 20 from the working steam 2a is transferred to the outside air via the housing member Ha (see Figure 3).

[0129] The working vapor 2a radiates heat to the upper sheet 20 in the condensation region CR, thereby losing the absorbed latent heat and condensing in the evaporation region SR, generating working liquid 2b. The generated working liquid 2b adheres to the wall surfaces 53a, 53b, 54a, and 54b of each vapor flow path recess 53 and 54, the flat surfaces 59a and 59b, the second lower sheet surface 10b of the lower sheet 10, and the first upper sheet surface 20a of the upper sheet 20. Here, the working liquid 2b continues to evaporate in the evaporation region SR. Therefore, the working liquid 2b in the region of the liquid flow path section 60 other than the evaporation region SR (i.e., the condensation region CR) is transported toward the evaporation region SR by the capillary action of each mainstream groove 61 (see the dashed arrows in FIG. 7). As a result, the working fluid 2b adhering to each of the wall surfaces 53a, 53b, 54a, 54b, the flat surfaces 59a, 59b, the second lower sheet surface 10b, and the first upper sheet surface 20a moves to the liquid flow path portion 60, passes through the communication grooves 65, and enters the main grooves 61. In this way, the working fluid 2b is filled into each of the main grooves 61 and each of the communication grooves 65. Therefore, the filled working fluid 2b obtains a driving force toward the evaporation region SR due to the capillary action of each of the main grooves 61, and is smoothly transported toward the evaporation region SR.

[0130] In the liquid flow path section 60, each mainstream groove 61 communicates with the adjacent other mainstream grooves 61 via the corresponding communication grooves 65. This allows the working fluid 2b to flow between adjacent mainstream grooves 61, preventing dryout in the mainstream grooves 61. As a result, capillary action is imparted to the working fluid 2b in each mainstream groove 61, and the working fluid 2b is smoothly transported toward the evaporation region SR.

[0131] Meanwhile, the working liquid 2b adhering to the wall surfaces 53a, 53b, 54a, 54b and flat surfaces 59a, 59b of each vapor flow path recess 53, 54 can also be transported to the evaporation region SR by capillary action of the vapor flow path recess 53, 54. The vapor flow path recess 53, 54 mainly functions as a flow path for the working vapor 2a, but capillary action can also be imparted to the working liquid 2b adhering to the wall surfaces 53a, 53b, 54a, 54b and flat surfaces 59a, 59b.

[0132] The working fluid 2b that has reached the evaporation region SR is again heated by the electronic device D and evaporates. The working vapor 2a that has evaporated from the working fluid 2b passes through the communication groove 65 in the evaporation region SR, moves to the lower vapor flow path recess 53 and the upper vapor flow path recess 54, which have large flow path cross-sectional areas, and diffuses within each of the vapor flow path recesses 53, 54. In this way, the working fluids 2a, 2b circulate within the sealed space 3 while repeatedly changing phases, i.e., evaporating and condensing, and diffuse and release the heat of the electronic device D. As a result, the electronic device D is cooled.

[0133] As described above, according to this embodiment, when viewed in a cross section perpendicular to the X direction, the upper opening 56 located on the second main body surface 30b extends from a region 56c that overlaps the lower opening 55 located on the first main body surface 30a in a plan view to a position that overlaps the main groove 61 in a plan view. This increases the flow path cross-sectional area of ​​the vapor passages 51, 52. This reduces the flow path resistance of the working vapor 2a, allowing the working vapor 2a to diffuse easily. As a result, the heat dissipation efficiency of the vapor chamber 1 can be improved, and the cooling efficiency of the electronic device D can be improved.

[0134] Furthermore, according to this embodiment, when viewed in a cross section perpendicular to the X direction, the upper steam flow path recess 54 includes flat surfaces 59a, 59b that connect the corresponding upper wall surface 54a and wall surface protrusions 57, 58. The flat surfaces 59a, 59b are formed flat. This further reduces the flow path resistance of the working steam 2a, making it easier to diffuse the working steam 2a.

[0135] Furthermore, according to this embodiment, when viewed in a cross section perpendicular to the X direction, the upper opening 56 extends from a region 56c that overlaps the lower opening 55 in a planar view to positions that overlap the main groove 61 on both sides of the lower opening 55 in a planar view. This further increases the flow path cross-sectional area of ​​the vapor passages 51, 52. This reduces the flow path resistance of the working vapor 2a, allowing the working vapor 2a to diffuse easily. As a result, the heat dissipation efficiency of the vapor chamber 1 can be improved, and the cooling efficiency of the electronic device D can be improved.

[0136] In the above-described embodiment, an example has been described in which, when viewed in a cross section perpendicular to the X direction, the upper opening 56 extends from the region 56c overlapping the lower opening 55 in a plan view to positions overlapping the mainstream grooves 61 in a plan view on both sides of the lower opening 55. However, this is not limited to this. For example, as shown in FIG. 11 , the upper opening 56 may extend from the region 56c overlapping the lower opening 55 in a plan view to a position overlapping the mainstream groove 61 in a plan view on one side of the lower opening 55. The upper opening 56 does not have to extend to a position overlapping the mainstream groove 61 in a plan view on the other side of the lower opening 55. Even in this case, the flow path cross-sectional area of ​​the steam passages 51, 52 can be increased. In the example shown in FIG. 11 , the upper opening 56 extends to the left of the lower opening 55. When viewed in a cross section perpendicular to the X direction, the upper steam flow path recess 54 includes one flat surface 59a. The flat surface 59a is disposed on the side where the upper opening 56 extends. The flat surface 59a connects one upper wall surface 54a and the first wall surface protrusion 57. The other upper wall surface 54b and the second wall surface protrusion 58 are connected without an intervening flat surface 59b (see FIG. 8A). The upper opening side edge 56b, which is located on the opposite side from the flat surface 59a, may be positioned so as to overlap the corresponding lower opening side edge 55b in a plan view. In the example shown in FIG. 11, the center 55a of the lower opening 55 and the center 56a of the upper opening 56 may be positioned so as to be offset from each other.

[0137] In the above-described embodiment, the upper steam flow path recess 54 includes flat surfaces 59a and 59b when viewed in a cross section perpendicular to the X direction. However, this is not limiting. For example, as shown in FIG. 12 , the upper steam flow path recess 54 may include convex surfaces 75a and 75b. The convex surfaces 75a and 75b connect the corresponding upper wall surfaces 54a and 54b to the wall surface protrusions 57 and 58. The convex surface 75a is the left surface in FIG. 12 , and the convex surface 75b is the right surface in FIG. 12 . More specifically, the upper wall surface 54a is connected to the first wall surface protrusion 57 via one convex surface 75a, and the upper wall surface 54b is connected to the second wall surface protrusion 58 via the other convex surface 75b. The convex surfaces 75a and 75b each include a spatial protrusion 76. The spatial convex portions 76 extend in the X direction and protrude toward the second main body surface 30b. This allows the working steam 2a to be rectified so that it flows along the spatial convex portions 76. This reduces the flow resistance of the working steam 2a, making it easier to diffuse the working steam 2a. Each of the convex surfaces 75a, 75b may include multiple spatial convex portions 76 spaced apart from one another. A concavely curved surface 77 may be formed between two adjacent spatial convex portions 76. A concavely curved surface 77 may also be formed between the wall surface protrusions 57, 58 and adjacent spatial convex portions 76. In the example shown in FIG. 12, the convex surfaces 75a, 75b include two spatial convex portions 76. In this case, the working steam 2a can be rectified even more.

[0138] 12, the depth of the upper steam flow path recess 54 is indicated by h3. h3 may be, for example, 20 μm to 250 μm. The depth h3 refers to the maximum distance from the second main body surface 30b to the convex surfaces 75a and 75b when viewed in a cross section perpendicular to the X direction. The depth h3 corresponds to the dimension in the Z direction.

[0139] 12, the depth from the second main body surface 30b to the spatial convex portion 76 is indicated by h4. h4 may be, for example, 17 μm to 245 μm. The depth h4 means the distance from the second main body surface 30b to the tip of the spatial convex portion 76 when viewed in a cross section perpendicular to the X direction. The depth h4 corresponds to the dimension in the Z direction.

[0140] 12, the spacing between the spatial convex portions 76 is indicated by w14. w14 may be, for example, 30 μm to 300 μm. The spacing w14 refers to the pitch distance between adjacent spatial convex portions 76 when viewed in a cross section perpendicular to the X direction. The spacing w14 corresponds to the dimension in the Y direction.

[0141] In the above-described embodiment, the upper steam flow path recess 54 includes the flat surfaces 59a and 59b when viewed in a cross section perpendicular to the X direction. However, this is not limited to this. For example, as shown in FIG. 13 , the upper steam flow path recess 54 does not necessarily have to include the flat surfaces 59a and 59b. More specifically, the upper wall surfaces 54a and 54b are connected to the wall surface protrusions 57 and 58 without the intervening flat surfaces 59a and 59b. Even in this case, it is sufficient that the upper opening 56 located on the second main body surface 30b extends from a region 56c that overlaps with the lower opening 55 located on the first main body surface 30a in a plan view to a position that overlaps with the mainstream groove 61 in a plan view. This increases the flow path cross-sectional area of ​​the steam passages 51 and 52 and reduces the flow path resistance of the working steam 2a.

[0142] In the above-described embodiment, the lower wall surfaces 53a, 53b of the lower steam flow path recess 53 are curved concavely. However, this is not limiting. As shown in FIG. 14 , the lower wall surfaces 53a, 53b may be curved convexly. The lower wall surfaces 53a, 53b may be connected to the upper wall surfaces 54a, 54b without interposing wall surface protrusions 57, 58. The lower wall surfaces 53a, 53b may be connected to the upper wall surfaces 54a, 54b without interposing flat surfaces 59a, 59b. By curving the lower wall surfaces 53a, 53b convexly in this manner, the formation of the wall surface protrusions 57, 58 can be avoided. This increases the flow path cross-sectional area of ​​the steam paths 51, 52 and reduces the flow path resistance of the working steam 2a. The lower wall surfaces 53a, 53b and the upper wall surfaces 54a, 54b may be connected with flat surfaces 59a, 59b interposed therebetween.

[0143] In the above-described embodiment, the width w3 of the upper opening 56 is larger than the width w2 of the lower opening 55 over the entire region of the land 33 in the X direction. However, this is not limiting. For example, as shown in FIG. 15A, the region where the width w3 of the upper opening 56 is larger than the width w2 of the lower opening 55 may be a partial region of the land 33 in the X direction.

[0144] 15A, the upper opening 56 includes a first region 56d and a second region 56e. The first region 56d is a region of the upper opening 56 that extends from a region 56c that overlaps with the lower opening 55 in a plan view to a position where the upper opening 56 overlaps with the main groove 61 in a plan view. The second region 56e is a region of the upper opening 56 that does not extend from the region 56c that overlaps with the lower opening 55 in a plan view to a position where the upper opening 56 overlaps with the main groove 61 in a plan view. In the first region 56d, the width w3 is greater than the width w2. In the second region 56e, the width w3 is smaller than the width w3 in the first region 56d, as shown in FIG. 15B, for example. In the second region 56e, the width w3 may be equal to the width w2, and the upper opening 56 may overlap with the lower opening 55 in a plan view. More specifically, the upper opening edge 56b is positioned so as to overlap the corresponding lower opening edge 55b in a plan view, and the upper opening edge 56b is positioned so as to overlap the corresponding lower opening edge 55b in a plan view, thereby increasing the bonding area between the land portion 33 and the upper sheet 20 and improving the mechanical strength of the vapor chamber 1.

[0145] The positions of the first region 56d and the second region 56e in the X direction are arbitrary. For example, the first region 56d may be located in the evaporation region SR, and the second region 56e may be located in the condensation region CR. In this case, the flow path cross-sectional area of ​​the steam passages 51, 52 can be increased in the evaporation region SR, where the pressure of the working steam 2a tends to be high.

[0146] For example, the first region 56d may be located in the condensation region CR, and the second region 56e may be located in the evaporation region SR. In this case, the flow velocity of the working vapor 2a can be reduced in the condensation region CR, and condensation can be promoted.

[0147] For example, the first region 56d may be located in the middle of the vapor chamber 1 in the X direction. The first region 56d may be located in a region of the condensation region CR close to the evaporation region SR. In this case, the flow resistance of the working vapor diffused from the evaporation region SR can be reduced, and the working vapor 2a can be diffused to a position far from the evaporation region SR. This improves the heat dissipation efficiency of the vapor chamber 1.

[0148] (Second embodiment) Next, a main body sheet for a vapor chamber, a vapor chamber, and an electronic device according to a second embodiment of the present invention will be described with reference to FIGS.

[0149] The second embodiment shown in Figures 16 to 25 differs mainly in that the first wall surface protrusion is positioned offset from the midpoint between the first and second main body surfaces in the normal direction of the first main body surface. The other configurations are substantially the same as those of the first embodiment shown in Figures 1 to 15. In Figures 16 to 25, the same parts as those of the first embodiment shown in Figures 1 to 15 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0150] 16 and 17 , when viewed in a cross section perpendicular to the X direction, the center 55a of the lower opening 55 is shifted relative to the center 56a of the upper opening 56. More specifically, in the portion of the first steam passage 51 extending in the X direction, the center 55a of the lower opening 55 is shifted to one side in the Y direction relative to the center 56a of the upper opening 56. Similarly, in the second steam passage 52, the center 55a of the lower opening 55 is shifted to one side in the Y direction relative to the center 56a of the upper opening 56. In this way, in the present embodiment, the cross-sectional shapes of the first steam passage 51 and the second steam passage 52 may be asymmetric in the Y direction.

[0151] 16 and 17 show an example in which the center 55a of the lower opening 55 is shifted to the right relative to the center 56a of the upper opening 56, but it may also be shifted to the left. As shown in FIG. 17, the offset s1 between the center 55a of the lower opening 55 and the center 56a of the upper opening 56 may be, for example, 0.05 mm to (0.8 × w1) mm. By setting the offset s1 to 0.05 mm or more, the effects of the offset between the centers 55a and 56a, described below, can be realized. On the other hand, by setting the offset s1 to (0.8 × w1) mm or less, the width w1 of the land portion 33 can be set to 80% or less. In this case, the mechanical strength of the land portion 33 can be ensured, and deformation of the wick sheet 30 when a load is applied during diffusion bonding, etc., can be suppressed. Note that for clarity of the drawings, FIGS. 2, 6, and 7 show a state in which the center 55a of the lower opening 55 and the center 56a of the upper opening 56 are not shifted.

[0152] The width w1 (see FIG. 17) of the land portion 33 according to the present embodiment may be, for example, 100 μm to 1500 μm. The width w2 of the lower opening 55 according to the present embodiment may be, for example, 100 μm to 5000 μm. The width w3 of the upper opening 56 according to the present embodiment may be, for example, 100 μm to 5000 μm, similar to the width w2 of the lower opening 55 described above. However, the width w3 of the upper opening 56 may be different from the width w2 of the lower opening 55.

[0153] When viewed in a cross section perpendicular to the X direction, each lower opening side edge 55b is arranged to be shifted relative to the corresponding upper opening side edge 56b. Each lower opening side edge 55b is arranged to be shifted to the right relative to the corresponding upper opening side edge 56b.

[0154] Similarly, in the portion of the first steam passage 51 extending in the Y direction, the center 55a of the lower opening 55 may be shifted to one side in the X direction with respect to the center 56a of the upper opening 56. In this case, each lower opening side edge 55b may be shifted to one side with respect to the corresponding upper opening side edge 56b.

[0155] The pair of wall protrusions 57, 58 in this embodiment protrude obliquely toward each other. The first wall protrusion 57 protrudes toward the upper right. The second wall protrusion 58 protrudes toward the lower left.

[0156] In this embodiment, the first wall surface protrusion 57 is positioned offset in the Z direction from the intermediate position MP between the first main body surface 30a and the second main body surface 30b. The Z direction is the thickness direction of the wick sheet 30 and corresponds to the normal direction of the first main body surface 30a. As shown in FIG. 17 , the first wall surface protrusion 57 may be positioned closer to the first main body surface 30a than the intermediate position MP. In this case, the first wall surface protrusion 57 is positioned closer to the first main body surface 30a than the second main body surface 30b. The distance s2 from the first main body surface 30a to the first wall surface protrusion 57 may be, for example, greater than or equal to h1 and less than t4 / 2. h1 is the depth of the main groove 61 as described above. t4 is the thickness of the wick sheet 30 as described above.

[0157] Similarly, in this embodiment, the second wall surface protrusion 58 is positioned offset in the Z direction from the intermediate position MP between the first body surface 30a and the second body surface 30b. As shown in FIG. 17 , the second wall surface protrusion 58 may be positioned closer to the second body surface 30b than the intermediate position MP. In this case, the second wall surface protrusion 58 is positioned closer to the second body surface 30b than the first body surface 30a. The distance s3 from the second body surface 30b to the second wall surface protrusion 58 may be equal to or different from the distance s2 from the first body surface 30a to the first wall surface protrusion 57. The distance s3 may be, for example, greater than or equal to h1 and less than t4 / 2.

[0158] Next, a method for manufacturing the vapor chamber 1 of this embodiment having such a configuration will be described with reference to FIGS.

[0159] First, the wick sheet manufacturing process for manufacturing the wick sheet 30 will be described.

[0160] First, as a material preparation step, a flat metal material sheet M including a lower surface Ma (an example of a first material surface) and an upper surface Mb (an example of a second material surface) is prepared, as shown in Fig. 18. The metal material sheet M may be formed from a rolled material having a desired thickness.

[0161] After the material preparation step, as shown in FIG. 19 , a resist formation step is performed in which a lower resist film 70 is formed on the lower surface Ma of the metal material sheet M, and an upper resist film 71 is formed on the upper surface Mb. Before forming each resist film 70, 71, the lower surface Ma and upper surface Mb of the metal material sheet M may be subjected to an acid degreasing treatment as a pretreatment. Alternatively, each resist film 70, 71 may be formed by applying a liquid resist to the lower surface Ma and upper surface Mb, followed by drying and curing. Alternatively, each resist film 70, 71 may be formed by attaching a dry film resist to the lower surface Ma and upper surface Mb.

[0162] 20 , in a patterning process, the lower resist film 70 and the upper resist film 71 are patterned by photolithography. In this case, a first resist opening 72 corresponding to the lower opening 55 is formed in the lower resist film 70, and a second resist opening 73 corresponding to the main groove 61 and the connecting groove 65 of the liquid flow path section 60 is formed. In addition, a third resist opening 74 corresponding to the upper opening 56 is formed in the upper resist film 71. The center of the first resist opening 72 is shifted to one side in the Y direction with respect to the center of the corresponding third resist opening 74. The Y-direction dimension w2′ of the first resist opening 72 may be equal to or different from the Y-direction dimension w3′ of the third resist opening 74. w2′ corresponds to the width w2 of the lower opening 55 and is a dimension set to form the width w2 of the lower opening 55 by etching. Similarly, w3' is a dimension corresponding to the width w3 of the lower opening 55, and is a dimension set in order to form the width w3 of the upper opening 56 by etching.

[0163] 21 , in an etching step, the lower surface Ma and the upper surface Mb of the metal material sheet M are etched. As a result, portions of the lower surface Ma of the metal material sheet M corresponding to the first resist opening 72 and the second resist opening 73 are etched. As a result, the lower vapor flow path recess 53 of the vapor flow path section 50, as well as the mainstream groove 61 and the connecting groove 65 of the liquid flow path section 60, as shown in FIG. 21 are formed. Furthermore, portions of the upper surface Mb corresponding to the third resist opening 74 are etched, forming the upper vapor flow path recess 54 of the vapor flow path section 50, as shown in FIG. 21 . Note that, as the etching solution, for example, an iron chloride-based etching solution such as a ferric chloride aqueous solution, or a copper chloride-based etching solution such as a copper chloride aqueous solution can be used.

[0164] The etching may be performed simultaneously on the lower surface Ma and the upper surface Mb of the metal material sheet M. However, this is not limited to this, and the etching of the lower surface Ma and the upper surface Mb may be performed in separate steps. Furthermore, the vapor flow path portion 50 and the liquid flow path portion 60 may be formed by etching simultaneously, or may be formed in separate steps.

[0165] In the etching step, the lower surface Ma and the upper surface Mb of the metal material sheet M are etched to obtain a predetermined outer contour shape of the wick sheet 30 as shown in FIGS.

[0166] After the etching step, as shown in FIG. 22, the lower resist film 70 and the upper resist film 71 are removed in a resist removal step.

[0167] In this manner, the wick sheet 30 according to this embodiment is obtained.

[0168] After the manufacturing process of the wick sheet 30, the lower sheet 10, the upper sheet 20, and the wick sheet 30 are joined together in a joining process as shown in Fig. 23. The lower sheet 10 and the upper sheet 20 may be formed from rolled material having a desired thickness.

[0169] More specifically, first, the lower sheet 10, the wick sheet 30, and the upper sheet 20 are laminated in this order. In this case, the first main body surface 30a of the wick sheet 30 is placed on the second lower sheet surface 10b of the lower sheet 10, and the first upper sheet surface 20a of the upper sheet 20 is placed on the second main body surface 30b of the wick sheet 30. At this time, the alignment holes 12 of the lower sheet 10, the alignment holes 35 of the wick sheet 30, and the alignment holes 22 of the upper sheet 20 are used to align the sheets 10, 20, and 30.

[0170] Next, the lower sheet 10, the wick sheet 30, and the upper sheet 20 are temporarily joined together. For example, these sheets 10, 20, and 30 may be temporarily joined together by spot resistance welding, or by laser welding.

[0171] Next, the lower sheet 10, the wick sheet 30, and the upper sheet 20 are permanently bonded together by diffusion bonding. Diffusion bonding is a method of bonding the lower sheet 10 and the wick sheet 30 together, and the wick sheet 30 and the upper sheet 20 together, to bond these sheets 10, 20, and 30. More specifically, the sheets 10, 20, and 30 are pressurized and heated in the stacking direction in a controlled atmosphere, such as a vacuum or an inert gas atmosphere. This utilizes atomic diffusion at the bonding surfaces to bond the sheets 10, 20, and 30. Diffusion bonding heats the materials of the sheets 10, 20, and 30 to a temperature close to, but lower than, their melting points, preventing the sheets 10, 20, and 30 from melting and deforming. More specifically, the first main body surface 30a of the frame portion 32 and the land portions 33 of the wick sheet 30 are diffusion bonded to the second lower sheet surface 10b of the lower sheet 10. Furthermore, the frame portion 32 of the wick sheet 30 and the second main body surface 30b of each land portion 33 are diffusion bonded to the first upper sheet surface 20a of the upper sheet 20. In this manner, the sheets 10, 20, and 30 are diffusion bonded to form a sealed space 3 having a vapor flow path portion 50 and a liquid flow path portion 60 between the lower sheet 10 and the upper sheet 20. In the above-mentioned injection portion 4, the lower injection protrusion 11 of the lower sheet 10 and the wick sheet injection protrusion 36 of the wick sheet 30 are diffusion bonded. The wick sheet injection protrusion 36 is diffusion bonded to the upper injection protrusion 21 of the upper sheet 20. As a result, the injection flow path 37 becomes a closed space.

[0172] After the joining step, the hydraulic fluid 2b is injected into the sealed space 3 from the injection part 4. During injection, the hydraulic fluid 2b passes through an injection flow path 37 and is supplied to the sealed space 3.

[0173] Thereafter, the above-mentioned injection flow path 37 is sealed. For example, the injection part 4 may be partially melted to seal the injection flow path 37. This blocks communication between the sealed space 3 and the outside, sealing the working fluid 2b in the sealed space 3 and preventing the working fluid 2b in the sealed space 3 from leaking to the outside. Note that the injection part 4 may be cut off after sealing.

[0174] In this manner, the vapor chamber 1 according to this embodiment is obtained.

[0175] The operation of the vapor chamber 1 according to this embodiment will be described below.

[0176] The working fluid 2b adhering to the wall surfaces 53a, 53b, 54a, and 54b of each vapor flow path recess 53 and 54 can also be transported to the evaporation region SR by capillary action of the vapor flow path recess 53 and 54. The vapor flow path recess 53 and 54 mainly function as a flow path for the working vapor 2a, but capillary action can also be imparted to the working fluid 2b adhering to the wall surfaces 53a, 53b, 54a, and 54b. When viewed in a cross section perpendicular to the X direction, if the length of the wall surfaces 53a, 53b, 54a, and 54b is short, the capillary action imparted to the working fluid 2b adhering to the wall surfaces 53a, 53b, 54a, and 54b can be enhanced. The wall length refers to the length along the wall surface when viewed in a cross section perpendicular to the X direction.

[0177] 17, in this embodiment, the first wall surface protrusion 57 is disposed closer to the first main body surface 30a in the Z direction than the intermediate position MP between the first main body surface 30a and the second main body surface 30b. In this case, the length of the lower wall surface 53a connected to the first wall surface protrusion 57 is shortened, and the capillary action of the working fluid 2b adhering to the lower wall surface 53a is enhanced.

[0178] On the other hand, when viewed in a cross section perpendicular to the X direction, the length of the upper wall surface 54a connected to the first wall surface protrusion 57 becomes longer. In this case, the effect of retaining the working fluid 2b on the upper wall surface 54a is enhanced, and the amount of working fluid 2b retained on the upper wall surface 54a can be increased. The working fluid 2b retained on the upper wall surface 54a moves over the first wall surface protrusion 57 to the lower wall surface 53a and is transported to the evaporation region SR by the capillary action of the lower wall surface 53a. Therefore, the amount of working fluid 2b transported to the evaporation region SR can be increased by the working fluid 2b retained on the upper wall surface 54a.

[0179] The lower wall surface 53a is connected to the first main body surface 30a, and the first main body surface 30a is provided with the main groove 61 and the communication groove 65 of the liquid flow path portion 60. In this case, the lower wall surface 53a and the liquid flow path portion 60 are close to each other, allowing the working fluid 2b to move between the lower wall surface 53a and the liquid flow path portion 60.

[0180] Similarly, in this embodiment, the second wall surface protrusion 58 is disposed closer to the second main body surface 30b in the Z direction than the intermediate position MP between the first main body surface 30a and the second main body surface 30b. In this case, the length of the upper wall surface 54b connected to the second wall surface protrusion 58 is shortened, and the capillary action imparted to the working fluid 2b adhering to the upper wall surface 54b is enhanced.

[0181] On the other hand, when viewed in a cross section perpendicular to the X direction, the length of the lower wall surface 53b connected to the second wall surface protrusion 58 becomes longer. In this case, the effect of retaining the working fluid 2b on the lower wall surface 53b is enhanced, and the amount of working fluid 2b retained on the lower wall surface 53b can be increased. The working fluid 2b retained on the lower wall surface 53b moves over the second wall surface protrusion 58 to the upper wall surface 54b and is transported to the evaporation region SR by the capillary action of the upper wall surface 54b. Therefore, the amount of working fluid 2b transported to the evaporation region SR can be increased by the working fluid 2b retained on the lower wall surface 53b.

[0182] The lower wall surface 53b is connected to the first main body surface 30a, and the main grooves 61 and the communication grooves 65 of the liquid flow path section 60 are provided on the first main body surface 30a. In this case, the lower wall surface 53b and the liquid flow path section 60 approach each other, and the working fluid 2b held on the lower wall surface 53b can move to the liquid flow path section 60. This also increases the amount of working fluid 2b transported to the evaporation region SR.

[0183] In this way, the working fluid 2b can be transported to the evaporation region SR not only by the liquid flow path section 60 but also by the vapor flow path section 50.

[0184] According to this embodiment, the lower wall surface 53a of the lower steam flow path recess 53 and the upper wall surface 54a of the upper steam flow path recess 54 are connected by the first wall surface protrusion 57. The first wall surface protrusion 57 protrudes toward the inside of the steam flow path section 50 and is positioned offset in the Z direction from the midpoint MP between the first main body surface 30a and the second main body surface 30b. This allows the lengths of the lower wall surface 53a and the upper wall surface 54a to be different when viewed in a cross section perpendicular to the X direction. This enhances the capillary action imparted to the working fluid 2b adhering to the shorter of the lower wall surface 53a and the upper wall surface 54a, and also enhances the retention of the working fluid 2b retained on the longer wall surface. For example, when the lower wall surface 53a is short, the working fluid 2b retained on the upper wall surface 54a can be transported to the evaporation region SR by the capillary action of the lower wall surface 53a. Therefore, the amount of the working fluid 2b transported to the evaporation region SR can be increased, and as a result, the heat dissipation efficiency of the vapor chamber 1 can be improved, and the cooling efficiency of the electronic device D can be improved.

[0185] Furthermore, according to this embodiment, the first main body surface 30a is provided with a liquid flow path portion 60 including a plurality of main grooves 61 and a plurality of communication grooves 65, and the first wall surface protrusion 57 is positioned closer to the first main body surface 30a than the intermediate position MP between the first main body surface 30a and the second main body surface 30b. This allows the first wall surface protrusion 57 to be positioned closer to the liquid flow path portion 60. This enhances the capillary action imparted to the working fluid 2b adhering to the lower wall surface 53a near the liquid flow path portion 60, allowing the working fluid 2b to travel between the lower wall surface 53a and the liquid flow path portion 60. In this case, the working fluid 2b can be collected in the lower wall surface 53a or the liquid flow path portion 60, whichever has the stronger capillary action, thereby increasing the amount of working fluid 2b transported to the evaporation region SR.

[0186] Furthermore, according to this embodiment, the lower wall surface 53b of the lower steam flow path recess 53 and the upper wall surface 54b of the upper steam flow path recess 54 are connected by a second wall surface protrusion 58. The second wall surface protrusion 58 protrudes toward the inside of the steam flow path section 50 and is positioned offset in the Z direction from the midpoint MP between the first main body surface 30a and the second main body surface 30b. This allows the lengths of the lower wall surface 53b and the upper wall surface 54b to be different when viewed in a cross section perpendicular to the X direction. This enhances the capillary action imparted to the working fluid 2b adhering to the shorter of the lower wall surface 53b and the upper wall surface 54b, and also enhances the retention of the working fluid 2b retained on the longer wall surface. For example, when the upper wall surface 54b is short, the working fluid 2b retained on the lower wall surface 53b can be transported to the evaporation region SR by the capillary action of the upper wall surface 54b. Therefore, the amount of the working fluid 2b transported to the evaporation region SR can be increased, and as a result, the heat dissipation efficiency of the vapor chamber 1 can be improved, and the cooling efficiency of the electronic device D can be improved.

[0187] Furthermore, according to this embodiment, the center 55a of the lower opening 55 of the vapor flow path portion 50, located on the first main body surface 30a of the wick sheet 30, is offset from the center 56a of the upper opening 56, located on the second main body surface 30b. This allows the first wall surface protrusion 57 and the second wall surface protrusion 58 to be easily offset from the intermediate position MP between the first main body surface 30a and the second main body surface 30b. This facilitates increasing the amount of working fluid 2b transported to the evaporation region SR. Furthermore, when the center 55a of the lower opening 55 is offset from the center 56a of the upper opening 56, the difference between the width w2 of the lower opening 55 and the width w3 of the upper opening 56 can be reduced. This prevents imbalance between the retention of working fluid 2b by the lower wall surface 53b and the retention of working fluid 2b by the upper wall surface 54a. This prevents the performance of the vapor chamber 1 from being affected by the vapor chamber 1's orientation, improving the reliability of the vapor chamber 1.

[0188] In the above-described embodiment, an example has been described in which the first wall surface protrusion 57 is positioned closer to the first body surface 30a than the intermediate position MP, and the second wall surface protrusion 58 is positioned closer to the second body surface 30b than the intermediate position MP. However, this is not limiting. For example, the first wall surface protrusion 57 may be positioned closer to the second body surface 30b than the intermediate position MP, and the second wall surface protrusion 58 may be positioned closer to the first body surface 30a than the intermediate position MP. In this case, the second wall surface protrusion 58 can be brought closer to the liquid flow path portion 60, allowing the hydraulic fluid 2b to move between the lower wall surface 53b and the liquid flow path portion 60. Alternatively, the second wall surface protrusion 58 may be positioned at the intermediate position MP.

[0189] Alternatively, as shown in FIG. 24, the first wall surface protrusion 57 may be positioned closer to the first main body surface 30a than the intermediate position MP, and the second wall surface protrusion 58 may be positioned closer to the first main body surface 30a than the intermediate position MP.

[0190] For example, in the etching step shown in FIG. 21 , the first resist opening 72 may be formed so as to reduce the etching rate of the lower vapor flow path recess 53, thereby forming the first wall surface protrusion 57 and the second wall surface protrusion 58 shown in FIG. 24 . In FIG. 24 , the distance s4 from the first body surface 30 a to the first wall surface protrusion 57 may be, for example, 20 μm or more. For example, the distance s4 may be less than t4 / 2 and less than h1. The distance s5 from the first body surface 30 a to the second wall surface protrusion 58 may be equal to or different from the distance s4. The distance s5 may be, for example, 20 μm or more. For example, the distance s5 may be less than t4 / 2 and less than h1.

[0191] According to the modification shown in FIG. 24 , the first wall surface protrusion 57 is positioned closer to the first main body surface 30a than the intermediate position MP, and the second wall surface protrusion 58 is positioned closer to the first main body surface 30a than the intermediate position MP. This allows the first wall surface protrusion 57 and the second wall surface protrusion 58 to be closer to the liquid flow path 60. This enhances the capillary action imparted to the working fluid 2b adhering to the lower wall surface 53a and the lower wall surface 53b near the liquid flow path 60. In this case, the working fluid 2b can move between the lower wall surface 53a and the liquid flow path 60, and the working fluid 2b can move between the lower wall surface 53b and the liquid flow path 60. This allows the working fluid 2b to be collected in areas of the lower wall surface 53a, the lower wall surface 53b, and the liquid flow path 60 where the capillary action is strong, thereby increasing the amount of working fluid 2b transported to the evaporation region SR.

[0192] 24, the first wall surface protrusion 57 is positioned closer to the first body surface 30a than the intermediate position MP, and the second wall surface protrusion 58 is positioned closer to the first body surface 30a than the intermediate position MP. This allows the flow path of the working vapor 2a diffusing within the upper vapor flow path recess 54 to approach a large circle. This reduces the flow path resistance of the working vapor 2a, allowing the working vapor 2a to diffuse more easily. This improves the heat dissipation efficiency of the vapor chamber 1 and the cooling efficiency of the electronic device D.

[0193] In the above-described embodiment, the lower wall surface 53b of the lower steam flow path recess 53 and the upper wall surface 54b of the upper steam flow path recess 54 are connected by the second wall surface protrusion 58. However, the present invention is not limited to this. For example, as shown in FIG. 25 , the lower wall surface 53b and the upper wall surface 54b may be formed in a continuous concave shape from the lower wall surface 53b to the upper wall surface 54b. In this case, the lower wall surface 53b and the upper wall surface 54b may be formed to bulge outward from the steam flow path recesses 53, 54. For example, the lower wall surface 53b and the upper wall surface 54b may be formed to bulge outward from the steam flow path recesses 53, 54 with respect to a straight line connecting the right lower opening edge 55b and the right upper opening edge 56b shown in FIG. 25 . The lower wall surface 53b and the upper wall surface 54b may be continuously and smoothly curved.

[0194] For example, in the etching process shown in FIG. 21 , the etching rate of the portion of the lower vapor flow channel recess 53 adjacent to the lower wall surface 53b may be increased relative to the etching rate of the portion of the lower wall surface 53a. For example, the first resist opening 72 may be formed to decrease the etching rate of the portion of the lower vapor flow channel recess 53 adjacent to the lower wall surface 53a. This allows the etching rate of the portion of the lower vapor flow channel recess 53 adjacent to the lower wall surface 53b to be increased compared to the etching rate of the portion of the lower wall surface 53a. Similarly, the third resist opening 74 may be formed to decrease the etching rate of the portion of the upper vapor flow channel recess 54 adjacent to the upper wall surface 54a. This allows the etching rate of the portion of the upper vapor flow channel recess 54 adjacent to the upper wall surface 54b to be increased compared to the etching rate of the portion of the upper wall surface 54a. In this way, the lower wall surface 53b and the upper wall surface 54b are formed so as not to form the second wall surface protrusion 58. As a result, the lower wall surface 53b and the upper wall surface 54b are formed in a continuous concave shape from the lower wall surface 53b to the upper wall surface 54b.

[0195] 25, the lower wall surface 53b and the upper wall surface 54b are formed in a continuous concave shape from the lower wall surface 53b to the upper wall surface 54b. This allows the flow path of the working vapor 2a diffusing within the vapor flow path recesses 53, 54 to approach a large circle. This reduces the flow path resistance of the working vapor 2a, allowing the working vapor 2a to diffuse easily. This improves the heat dissipation efficiency of the vapor chamber 1 and the cooling efficiency of the electronic device D.

[0196] (Third embodiment) Next, a main body sheet for a vapor chamber, a vapor chamber, and an electronic device according to a third embodiment of the present invention will be described with reference to FIGS.

[0197] In the third embodiment shown in Figures 26 to 35, third spatial recesses are provided on the second main body surface, located on both sides of the second spatial recess. A pair of third wall surface protrusions, connecting each wall surface of the second spatial recess to the corresponding third wall surface of the third spatial recess, protrude toward the second main body surface. These are the main differences. The other configurations are substantially the same as those of the second embodiment shown in Figures 16 to 25. In Figures 26 to 35, the same parts as those of the second embodiment shown in Figures 16 to 25 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0198] As shown in FIG. 26 , in the vapor chamber 1 of the present embodiment, the first vapor passage 51 and the second vapor passage 52 of the vapor passage section 50 each have a lower vapor passage recess 53, a first upper vapor passage recess 81, and a second upper vapor passage recess 82. The lower vapor passage recess 53 is an example of a first spatial recess and is provided in the first main body surface 30a. The first upper vapor passage recess 81 is an example of a second spatial recess and is provided in the second main body surface 30b. The second upper vapor passage recess 82 is an example of a third spatial recess and is provided in the second main body surface 30b. The first upper vapor passage recess 81 has a pair of first upper wall surfaces 81a and 81b. The first upper wall surfaces 81a and 81b are an example of second wall surfaces. The first upper wall surface 81a is the wall surface on the left side in FIG. 26 , and the first upper wall surface 81b is the wall surface on the right side in FIG. 26 . The first upper steam flow path recess 81 and the first upper wall surfaces 81a, 81b in this embodiment are substantially the same as the upper steam flow path recess 54 and the upper wall surfaces 54a, 54b shown in Fig. 16 etc. Therefore, detailed description of the first upper steam flow path recess 81 and the first upper wall surfaces 81a, 81b will be omitted.

[0199] 26, when viewed in a cross section perpendicular to the X direction, the second upper steam flow path recesses 82 are located on both sides of the first upper steam flow path recess 81. Each second upper steam flow path recess 82 communicates with the first upper steam flow path recess 81 and forms a continuous opening in the second main body surface 30b.

[0200] The second upper steam flow path recess 82 is formed in a concave shape on the second main body surface 30b by etching the second main body surface 30b of the wick sheet 30 in a second etching step described below. As a result, the second upper steam flow path recess 82 has a curved second upper wall surface 82a, as shown in FIG. 26 . The second upper wall surface 82a is an example of a third wall surface. The second upper wall surface 82a defines the second upper steam flow path recess 82 and constitutes a part of the first steam path 51 and a part of the second steam path 52.

[0201] The upper opening 83 in this embodiment is located in the second main body surface 30b, and is an opening of the first upper steam channel recess 81 and the second upper steam channel recess 82 in the second main body surface 30b. The planar shape of the upper opening 83 in the first steam channel 51 is a rectangular frame, as shown in FIG. 6. The planar shape of the upper opening 83 in the second steam channel 52 is an elongated rectangular shape, as shown in FIG. 6. The upper opening 83 is an opening defined by the first upper steam channel recess 81 and the second upper steam channel recess 82 in the second main body surface 30b.

[0202] The width w8 of the upper opening 83 may be, for example, 200 μm to 6000 μm. Here, the width w8 of the upper opening 83 is the dimension of the upper opening 83 in the Y direction. The width w8 of the upper opening 83 corresponds to the dimension in the Y direction of the portion of the first steam passage 51 extending in the X direction and also corresponds to the dimension in the Y direction of the second steam passage 52. In this embodiment, the dimension in the Y direction between the second upper wall surfaces 82a of the pair of second upper steam flow path recesses 82 that define the steam passages 51, 52 gradually increases from the first main body surface 30a toward the second main body surface 30b and is maximum at the second main body surface 30b. Therefore, the width w8 is the maximum dimension in the Y direction between the pair of second upper wall surfaces 82a. However, the dimension in the Y direction between the pair of second upper wall surfaces 82a does not have to be maximum at the second main body surface 30b. For example, the position where the dimension in the Y direction between the pair of second upper wall surfaces 82a is maximum may be located closer to the first main body surface 30a than to the second main body surface 30b. Note that the width w8 also corresponds to the dimension in the X direction of the portion of the first steam passage 51 extending in the Y direction. Furthermore, the width w8 of the upper opening 83 may be larger than the width w2 of the lower opening 55. In the present embodiment as well, the upper opening 83 may extend from the region 56c that overlaps with the lower opening 55 in a plan view to a position that overlaps with the mainstream groove 61 in a plan view.

[0203] In the present embodiment, the cross-sectional shapes of the first steam passage 51 and the second steam passage 52 may be symmetrical in the Y direction. That is, the center 55a of the lower opening 55 may be located at the same position in the Y direction as the center 83a of the upper opening 83.

[0204] The upper opening 83 is defined by a pair of upper opening side edges 83b (an example of second opening side edges) extending in the X direction. The center 83a of the upper opening 83 described above is the midpoint of the pair of upper opening side edges 83b when viewed in a cross section perpendicular to the X direction. In Fig. 26, the upper opening side edges 83b are shown as the intersection of the second main body surface 30b and the second upper wall surface 82a of the second upper steam flow path recess 82, and the midpoint of these intersections is the center 83a of the upper opening 83.

[0205] Each upper opening edge 83b is offset to one side relative to the corresponding lower opening edge 55b. In Figure 26, the right upper opening edge 83b of the upper opening 83 is offset to the right relative to the right lower opening edge 55b of the lower opening 55, and the left upper opening edge 83b is offset to the left relative to the left lower opening edge 55b. In this way, the width w8 of the upper opening 83 is greater than the width w2 of the lower opening 55.

[0206] In the present embodiment, the first upper wall surfaces 81a, 81b of the first upper steam flow path recess 81 do not extend to the second body surface 30b. The width w9 of the opening when the first upper wall surfaces 81a, 81b are extended to the second body surface 30b along the curved shapes of the first upper wall surfaces 81a, 81b may be equal to the width w3 of the upper opening 56 shown in Fig. 17. That is, in a first patterning step described below, the third resist opening 94 formed in the first upper resist film 91 formed on the second body surface 30b may be equal to the first resist opening 92 formed in the first lower resist film 90 formed on the first body surface 30a.

[0207] 26, each of the first upper wall surfaces 81a, 81b of the first upper steam flow path recess 81 and the corresponding second upper wall surface 82a of the second upper steam flow path recess 82 are connected by a third wall surface protrusion 84. As a result, the first upper wall surfaces 81a, 81b do not extend to the second main body surface 30b, and the first upper steam flow path recess 81 communicates with the second upper steam flow path recess 82 on its side.

[0208] The third wall surface protrusion 84 may protrude toward the second main body surface 30b. The third wall surface protrusion 84 may be formed to jut out toward the upper sheet 20. The third wall surface protrusion 84 is located closer to the first main body surface 30a than the second main body surface 30b, and is spaced apart from the first upper sheet surface 20a of the upper sheet 20.

[0209] The lower wall surfaces 53a, 53b of the lower steam flow path recess 53 and the corresponding first upper wall surfaces 81a, 81b of the first upper steam flow path recess 81 are connected by wall surface protrusions 57, 58. More specifically, the lower wall surface 53a of the lower steam flow path recess 53 and the corresponding first upper wall surface 81a of the first upper steam flow path recess 81 are connected by the first wall surface protrusion 57. The lower wall surface 53b of the lower steam flow path recess 53 and the corresponding first upper wall surface 81b of the first upper steam flow path recess 81 are connected by the second wall surface protrusion 58. The first wall surface protrusion 57 is the wall surface protrusion on the left side in FIG. 26 , and the second wall surface protrusion 58 is the wall surface protrusion on the right side in FIG. 26 .

[0210] 26, the first wall surface protrusion 57 may be disposed at an intermediate position MP between the first body surface 30a and the second body surface 30b. The second wall surface protrusion 58 may be disposed at an intermediate position MP between the first body surface 30a and the second body surface 30b.

[0211] A pair of wall surface protrusions 57, 58 defines a through portion 34, and the lower steam flow path recess 53 and the first upper steam flow path recess 81 communicate with each other in the through portion 34. The width w10 of such a through portion 34 (see FIG. 26) may be, for example, 400 μm to 1600 μm. Here, the width w10 of the through portion 34 corresponds to the gap between adjacent land portions 33 in the Y direction. More specifically, the width w10 means the distance in the Y direction between the tip of the first wall surface protrusion 57 and the tip of the second wall surface protrusion 58 that define the through portion 34.

[0212] Furthermore, the width w11 (see FIG. 26) of the land portion 33 according to this embodiment may be, for example, 100 μm to 1500 μm. Here, the width w11 of the land portion 33 is the maximum dimension of the land portion 33 in the Y direction. More specifically, the width w11 of the land portion 33 means the distance in the Y direction between the tip of the first wall surface protrusion 57 and the tip of the second wall surface protrusion 58 that define the land portion 33.

[0213] Next, a method for manufacturing the vapor chamber 1 of this embodiment configured as described above will be described with reference to Figures 27 to 34. Here, differences from the second embodiment will be mainly described.

[0214] After the material preparation step shown in Fig. 18, as a first resist formation step, a first lower resist film 90 is formed on the lower surface Ma of the metal material sheet M, and a first upper resist film 91 is formed on the upper surface Mb, as shown in Fig. 27. The first resist formation step may be performed in the same manner as the resist formation step shown in Fig. 19.

[0215] 28, in a first patterning step, a first lower resist film 90 and a first upper resist film 91 are patterned by photolithography. In this case, a first resist opening 92 corresponding to the lower opening 55 is formed in the first lower resist film 90, and a second resist opening 93 corresponding to the main groove 61 and the connecting groove 65 of the liquid flow path section 60 is formed. Furthermore, a third resist opening 94 corresponding to the upper opening 83 is formed in the first upper resist film 91. The Y-direction dimension w9' of the third resist opening 94 corresponds to the width w9 shown in FIG. 26 and is a dimension set for forming the width w9 by etching. w9' may be equal to or different from the Y-direction dimension w3' of the first resist opening 92.

[0216] Subsequently, as shown in Fig. 29, in a first etching step, the lower surface Ma and upper surface Mb of the metal material sheet M are etched in the same manner as in the etching step shown in Fig. 21. As a result, the lower vapor flow path recess 53 of the vapor flow path section 50, and the main groove 61 and the connecting groove 65 of the liquid flow path section 60, as shown in Fig. 29, are formed on the lower surface Ma of the metal material sheet M. In addition, the first upper vapor flow path recess 81 of the vapor flow path section 50 is formed on the upper surface Mb.

[0217] After the first etching step, as shown in FIG. 30, the first lower resist film 90 and the first upper resist film 91 are removed in a first resist removal step.

[0218] After the first resist removal step, as shown in FIG. 31 , in a second resist formation step, a second lower resist film 95 is formed on the lower surface Ma of the metal material sheet M, and a second upper resist film 96 is formed on the upper surface Mb. Furthermore, a wall surface resist film 97 is formed on the lower wall surfaces 53a, 53b of the lower steam flow path recess 53 and the first upper wall surfaces 81a, 81b of the first upper steam flow path recess 81. The second lower resist film 95, the second upper resist film 96, and the wall surface resist film 97 may be formed using a liquid resist. In this case, the wall surface resist film 97 can be easily formed on the lower wall surfaces 53a, 53b and the first upper wall surfaces 81a, 81b. Before forming the resist films 95 to 97, the lower surface Ma and upper surface Mb of the metal material sheet M and the wall surfaces 53a, 53b, 81a, 81b may be subjected to an acid degreasing treatment as a pretreatment.

[0219] 32, in a second patterning step, a second upper resist film 96 and a wall surface resist film 97 are patterned by photolithography. In this case, a fourth resist opening 98 corresponding to the second upper steam flow path recess 82 is formed in the second upper resist film 96 and the wall surface resist film 97. The fourth resist opening 98 is formed to extend from the second upper resist film 96 to the wall surface resist film 97. As shown in FIG. 32, the fourth resist opening 98 may be formed so that the opening edge on the opposite side to the first upper steam flow path recess 81 satisfies the dimension w8' in the Y direction. w8' is a dimension corresponding to the width w8 of the upper opening 83 and is a dimension set for forming the width w8 of the upper opening 83 by etching.

[0220] 33, in a second etching step, the upper surface Mb of the metal material sheet M and the first upper wall surfaces 81a, 81b of the first upper steam flow path recess 81 are etched in the same manner as in the etching step shown in Fig. 21. As a result, the second upper steam flow path recess 82 of the steam flow path section 50 is formed on the upper surface Mb and the first upper wall surfaces 81a, 81b of the metal material sheet M.

[0221] After the second etching step, as shown in FIG. 34, the second lower resist film 95 and the second upper resist film 96 are removed in a second resist removal step.

[0222] In this manner, the wick sheet 30 according to this embodiment is obtained.

[0223] As described above, according to the present embodiment, the first upper wall surfaces 81a, 81b of the first upper steam flow path recess 81 and the second upper wall surfaces 82a of the second upper steam flow path recess 82 located on both sides of the first upper steam flow path recess 81 are connected by the third wall surface protrusions 84. The third wall surface protrusions 84 protrude toward the second main body surface 30b. This prevents the second upper sheet surface 20b of the upper sheet 20 from deforming into a concave shape. That is, a portion of the upper sheet 20 overlapping the upper opening 83 may receive atmospheric pressure on the second upper sheet surface 20b and enter the first upper steam flow path recess 81 and the second upper steam flow path recess 82 of the decompressed steam flow path section 50. In this case, this portion of the upper sheet 20 can be prevented from entering deeper than the third wall surface protrusions 84. This prevents the second upper sheet surface 20b of the upper sheet 20 from deforming into a concave shape. In this case, the adhesion between the electronic device D and the lower sheet 10 can be improved, and the thermal resistance between the electronic device D and the vapor chamber 1 can be reduced.

[0224] In the above-described embodiment, the first wall surface protrusion 57 and the second wall surface protrusion 58 are disposed at the intermediate position MP between the first main body surface 30a and the second main body surface 30b in the Z direction. However, the present invention is not limited to this.

[0225] For example, as shown in Fig. 35, the first wall surface protrusion 57 may be positioned offset in the Z direction from the intermediate position MP. In Fig. 35, the first wall surface protrusion 57 is positioned closer to the first main body surface 30a than the intermediate position MP. The distance s2 from the first main body surface 30a to the first wall surface protrusion 57 may be the same as the distance s2 shown in Fig. 17.

[0226] As shown in Fig. 35, the second wall surface protrusion 58 may be positioned offset from the intermediate position MP in the Z direction. In Fig. 35, the second wall surface protrusion 58 is positioned closer to the second main body surface 30b than the intermediate position MP. The distance s3 from the second main body surface 30b to the second wall surface protrusion 58 may be the same as the distance s3 shown in Fig. 17.

[0227] In the modified example shown in Fig. 35, the first wall surface protrusion 57 and the second wall surface protrusion 58 are arranged in the same manner as in the example shown in Fig. 17. In this case, the cross-sectional shapes of the first steam passage 51 and the second steam passage 52 may be asymmetric in the Y direction.

[0228] 35, center 55a of lower opening 55 is shifted to one side in the Y direction with respect to center 83a of upper opening 83. Although an example in which lower opening 55 is shifted to the right with respect to upper opening 83 is shown in FIG. 35, lower opening 55 may be shifted to the left. The amount of shift between center 55a of lower opening 55 and center 83a of upper opening 83 may be equal to shift amount s1 shown in FIG.

[0229] In FIG. 35 , the right upper opening edge 83b of the upper opening 83 is shifted to the right relative to the right lower opening edge 55b of the lower opening 55, and the left upper opening edge 83b is shifted to the left relative to the left lower opening edge 55b. In this manner, the width w8 of the upper opening 83 is greater than the width w2 of the lower opening 55. However, as long as the width w8 of the upper opening 83 is greater than the width w2 of the lower opening 55, the right upper opening edge 83b of the upper opening 83 may be shifted to the left relative to the right lower opening edge 55b of the lower opening 55. Alternatively, in this case, the right upper opening edge 83b of the upper opening 83 may be positioned in the same position as the right lower opening edge 55b.

[0230] (Fourth embodiment) Next, a main body sheet for a vapor chamber, a vapor chamber, and an electronic device according to a fourth embodiment of the present invention will be described with reference to FIGS.

[0231] The fourth embodiment shown in Figures 36 to 47 differs mainly in that the first wall surface end portion located on the first main body surface side is located more inward of the steam flow path portion than the protrusion portion in plan view. The other configurations are substantially the same as those of the first embodiment shown in Figures 1 to 17. In Figures 36 to 47, the same parts as those of the first embodiment shown in Figures 1 to 17 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0232] A vapor chamber 100 according to this embodiment will now be described. As shown in Figures 36 and 37, the vapor chamber 100 has a sealed space 103 in which working fluids 2a and 2b are sealed. The working fluids 2a and 2b in the sealed space 103 repeatedly undergo phase changes, thereby effectively cooling the electronic device D of the electronic device E described above.

[0233] 36 and 37, the vapor chamber 100 includes a lower sheet 110, an upper sheet 120, and a wick sheet 130 for the vapor chamber. The wick sheet 130 for the vapor chamber will be simply referred to as the wick sheet 130 hereinafter. The vapor chamber 100 according to this embodiment has the lower sheet 110, the wick sheet 130, and the upper sheet 120 stacked in this order.

[0234] The vapor chamber 100 is generally formed in the shape of a thin, flat plate. The planar shape of the vapor chamber 100 is arbitrary, but may be a rectangle as shown in FIG. 36 . The planar shape of the vapor chamber 100 may be, for example, a rectangle with one side measuring 50 mm to 200 mm and the other side measuring 150 mm to 60 mm, or a square with one side measuring 70 mm to 300 mm. The planar dimensions of the vapor chamber 100 are arbitrary. In this embodiment, as an example, an example in which the planar shape of the vapor chamber 100 is a rectangle with the X direction (described later) as the longitudinal direction will be described. In this case, as shown in FIGS. 38 to 41 , the lower sheet 110, the upper sheet 120, and the wick sheet 130 may have the same planar shape as the vapor chamber 100. Furthermore, the planar shape of the vapor chamber 100 is not limited to a rectangle, but may be any shape, such as a circle, an ellipse, an L-shape, or a T-shape.

[0235] As shown in FIG. 36, the vapor chamber 100 has an evaporation region SR where the working fluids 2a and 2b evaporate, and a condensation region CR where the working fluids 2a and 2b condense.

[0236] The evaporation region SR is a region that overlaps with the electronic device D in a planar view and is a region where the electronic device D is attached. The evaporation region SR may be located anywhere in the vapor chamber 100. In this embodiment, the evaporation region SR is formed on one side of the vapor chamber 100 in the X direction (the left side in FIG. 36 ). Heat from the electronic device D is transferred to the evaporation region SR, and this heat causes the working fluid 2b to evaporate in the evaporation region SR. The heat from the electronic device D may be transferred not only to the region that overlaps with the electronic device D in a planar view, but also to the periphery of that region. Therefore, the evaporation region SR includes the region that overlaps with the electronic device D and the periphery thereof in a planar view. Here, the planar view may refer to a state in which the vapor chamber 100 is viewed from a direction perpendicular to the surface that receives heat from the electronic device D and the surface that releases the received heat. The heat-receiving surface corresponds to the second upper sheet surface 120b of the upper sheet 120, which will be described later. The surface that releases heat corresponds to a first lower sheet surface 110a (described later) of the lower sheet 110. For example, as shown in Fig. 36, the vapor chamber 100 viewed from above or below corresponds to a plan view.

[0237] The condensation region CR is a region that does not overlap with the electronic device D in a plan view, and is a region where the working vapor 2a mainly releases heat and condenses. The condensation region CR may be a region surrounding the evaporation region SR. In the condensation region CR, heat from the working vapor 2a is released to the lower sheet 110, and the working vapor 2a is cooled and condensed in the condensation region CR.

[0238] When vapor chamber 100 is installed inside a mobile terminal, the up-down relationship may be lost depending on the attitude of the mobile terminal. However, in this embodiment, for convenience, the sheet that receives heat from electronic device D will be referred to as upper sheet 120, and the sheet that dissipates the received heat will be referred to as lower sheet 110. For this reason, the following description will be given assuming that lower sheet 110 is disposed on the lower side and upper sheet 120 is disposed on the upper side.

[0239] As shown in FIG. 37, the lower sheet 110 is an example of a first sheet. The lower sheet 110 has a first lower sheet surface 110a located on the opposite side from the wick sheet 130 and a second lower sheet surface 110b located on the opposite side from the first lower sheet surface 110a. The second lower sheet surface 110b is located on the wick sheet 130 side. The lower sheet 110 may be formed to be generally flat, or may have a uniform thickness overall. A housing member Ha that forms part of the housing of a mobile terminal or the like may be attached to the first lower sheet surface 110a. The first lower sheet surface 110a may be entirely covered with the housing member Ha. As shown in FIG. 38, alignment holes 112 may be provided at the four corners of the lower sheet 110.

[0240] As shown in FIG. 37, the upper sheet 120 is an example of the second sheet. The upper sheet 120 has a first upper sheet surface 120a provided on the wick sheet 130 side and a second upper sheet surface 120b located on the opposite side to the first upper sheet surface 120a. The upper sheet 120 may be formed to be generally flat, or may have a uniform thickness overall. The above-mentioned electronic device D may be attached to this second upper sheet surface 120b. As shown in FIG. 39, alignment holes 122 may be provided at the four corners of the upper sheet 120.

[0241] 37, the wick sheet 130 is an example of a main body sheet. The wick sheet 130 includes a vapor flow path section 150 and a liquid flow path section 160 disposed adjacent to the vapor flow path section 150. The wick sheet 130 also includes a first main body surface 131a and a second main body surface 131b located on the opposite side of the first main body surface 131a. The first main body surface 131a is disposed on the side of the lower sheet 110, and the second main body surface 131b is disposed on the side of the upper sheet 120.

[0242] The second lower sheet surface 110b of the lower sheet 110 and the first main body surface 131a of the wick sheet 130 may be permanently bonded to each other by diffusion bonding. Similarly, the first upper sheet surface 120a of the upper sheet 120 and the second main body surface 131b of the wick sheet 130 may be permanently bonded to each other by diffusion bonding. Note that the lower sheet 110, the upper sheet 120, and the wick sheet 130 may be bonded by other methods, such as brazing, instead of diffusion bonding, as long as they can be permanently bonded.

[0243] As shown in FIGS. 37, 40, and 41, the wick sheet 130 according to this embodiment has a frame portion 132 formed in a rectangular frame shape in a plan view and land portions 133 provided within the frame portion 132. The frame portion 132 and each land portion 133 extend from the first main body surface 131a to the second main body surface 131b. The frame portion 132 and the land portions 133 are portions where the material of the wick sheet 130 remains without being etched in the etching process described below. In this embodiment, the frame portion 132 is formed in a rectangular frame shape in a plan view. A steam flow path portion 150 is defined inside the frame portion 132. The working steam 2a flows inside the frame portion 132 and around the land portions 133.

[0244] In this embodiment, the land portion 133 may extend in an elongated shape with the X direction as the longitudinal direction in a plan view. The planar shape of the land portion 133 may be an elongated rectangular shape. The land portions 133 may be arranged parallel to one another and spaced at equal intervals in the Y direction. The working steam 2a flows around each land portion 133 and is transported toward the condensation region CR. This prevents the flow of the working steam 2a from being obstructed. The width w21 of the land portion 133 (see FIG. 42) may be, for example, 36 μm or more and 4000 μm or less. Here, the width w21 of the land portion 133 is the dimension of the land portion 133 in the Y direction and means the dimension at the widest position of the land portion 133 (for example, the position where the first wall surface end portion 153b described later is present).

[0245] The frame portion 132 and each land portion 133 are diffusion-bonded to the lower sheet 110 and the upper sheet 120. This improves the mechanical strength of the vapor chamber 100. A first wall surface 153a, a second wall surface 154a, and a protrusion 155 of the vapor passage 151 (described later) form the side walls of the land portion 133. A first wall surface 153a, a second wall surface 154a, and a protrusion 155 are formed on both sides of each land portion 133 in the width direction (X direction). The cross-sectional shape of each land portion 133 along the width direction (X direction) (see FIG. 42) may be line-symmetric. The width w26 of the land portion 133 at the position where the protrusion 155 is present may be, for example, 30 μm or more and 3000 μm or less. The first main body surface 131a and the second main body surface 131b of the wick sheet 130 may be formed flat across the frame body portion 132 and each land portion 133. In FIG. 37, the side walls of the frame body portion 132 have substantially the same shape as the side walls of the land portions 133. However, this is not limiting, and the side walls of the frame body portion 132 do not necessarily have substantially the same shape as the side walls of the land portions 133.

[0246] The steam flow path section 50 is an example of a through space. The steam flow path section 150 is a flow path through which the working steam 2a mainly passes. The steam flow path section 150 extends from the first main body surface 131a to the second main body surface 131b and penetrates the wick sheet 130.

[0247] As shown in Figures 40 and 41, the steam flow path section 150 in this embodiment has a plurality of steam passages 151. Each steam passage 151 is formed inside the frame body section 132 and outside the land section 133. That is, the steam passages 151 are formed between the frame body section 132 and the land section 133, and between adjacent land sections 133. The planar shape of each steam passage 151 is an elongated rectangle. The steam flow path section 150 is divided into a plurality of steam passages 151 by the plurality of land sections 133.

[0248] 37, the vapor passages 151 are formed to extend from the first main body surface 131a to the second main body surface 131b of the wick sheet 130. The vapor passages 151 may be formed by etching the first main body surface 131a and the second main body surface 131b of the wick sheet 130, respectively, in an etching step described below.

[0249] As shown in FIG. 42, the steam passage 151 has a curved first wall surface 153a and a curved second wall surface 154a. The first wall surface 153a is located on the side of the first main body surface 131a and is curved in a curved shape that is recessed toward the inside of the land portion 133 in the width direction. The second wall surface 154a is located on the side of the second main body surface 131b and is curved in a curved shape that is recessed toward the inside of the land portion 133 in the width direction. The first wall surface 153a and the second wall surface 154a join at a protrusion 155 formed to protrude toward the inside of the steam passage 151. The protrusion 155 may be formed at an acute or obtuse angle in cross section. A width w27 (see FIG. 42) between a pair of adjacent protrusions 155 across the steam passage 151 may be, for example, 30 μm or more and 3000 μm or less. Here, the width w27 between the pair of protrusions 155 refers to the distance measured in the width direction (Y direction) of the steam passage 151 at the position where the protrusions 155 are present.

[0250] The first wall surface 153a has a first wall surface end 153b located on the first main body surface 131a side. The upper end of the first wall surface 153a is a protrusion 155, which corresponds to the end of the first wall surface 153a on the second main body surface 131b side. The lower end of the first wall surface 153a is a first wall surface end 153b, which corresponds to the end of the first wall surface 153a on the first main body surface 131a side. The first wall surface 153a contacts the lower sheet 110 at the first wall surface end 153b. The first wall surface end 153b may be formed at an acute angle in cross section. In addition, in FIG. 42, the point of the first wall surface 153a that is most recessed inward in the width direction (Y direction) of the land portion 133 in cross section is indicated by reference symbol 153c.

[0251] The second wall surface 154a has a second wall surface end portion 154b located on the second main body surface 131b side. The upper end of the second wall surface 154a is the second wall surface end portion 154b, which corresponds to the end of the second wall surface 154a on the second main body surface 131b side. The lower end of the second wall surface 154a is a protrusion 155, which corresponds to the end of the second wall surface 154a on the first main body surface 131a side. The second wall surface 154a contacts the upper sheet 120 at the second wall surface end portion 154b. The second wall surface end portion 154b may also form the outer edge of a protrusion 164, which will be described later. The second wall surface end portion 154b may be formed at an obtuse angle in a cross-sectional view.

[0252] In this embodiment, the first wall surface end 153b is located closer to the steam channel section 150 than the protrusion 155 in a plan view. That is, in a plan view, the second wall surface end 154b, the point 153c, the protrusion 155, and the first wall surface end 153b are located in this order from the inside to the outside in the width direction (Y direction) of the land portion 133. The outside corresponds to the side of the steam channel section 150. The planar area of ​​the steam channel 151 is maximum at the position where the second wall surface end 154b is located and minimum at the position where the first wall surface end 153b is located. The width w22 of the steam channel 151 (see FIG. 42) may be, for example, 100 μm or more and 5000 μm or less. Here, the width w22 of the steam channel 151 is the width at the narrowest portion of the steam channel 151. In this case, it refers to the distance measured in the width direction (Y direction) at the position where the first wall surface end 153b is located. The width w22 of the steam passage 151 corresponds to the gap between the land portions 133 adjacent to each other in the width direction (Y direction).

[0253] As shown in FIG. 42, the distance between the second wall surface end 154b and the protrusion 155 in the width direction (Y direction) of the steam channel section 150 is defined as Lp, and the distance between the second wall surface end 154b and the first wall surface end 153b is defined as Ls. In this case, the distance Ls may be 1.05 to 2 times the distance Lp, or 1.05 to 1.8 times the distance Lp. Setting the distance Ls to 1.05 times the distance Lp increases the bonding area between the land portion 133 and the lower sheet 110, thereby enhancing the strength of the diffusion bonding near the first wall surface end 153b. Setting the distance Ls to 2 times the distance Lp or less ensures a sufficient width for the steam channel 151, allowing the working steam 2a to flow smoothly through the steam channel 151. The distance Ls may be 6 μm to 500 μm. The distance Lp may be 3 μm to 400 μm.

[0254] Furthermore, the distance Ls between the second wall surface end 154b and the first wall surface end 153b may be 1.1 to 10 times the width w25 of the convex portion 164, which will be described later. By making the distance Ls 1.1 times or more the width w25, the bonding area between the land portion 133 and the lower sheet 110 increases, and the strength of the bond formed by diffusion bonding, brazing, or the like near the first wall surface end 153b can be increased. By making the distance Ls 10 times or less the width w25, the width of the steam passage 151 is ensured, allowing the working steam 2a to flow smoothly through the steam passage 151.

[0255] The protrusions 155 in the thickness direction (Z direction) of the wick sheet 130 are located closer to the second main body surface 131b than the intermediate position Pz between the first main body surface 131a and the second main body surface 131b. When the distance between the protrusions 155 and the second main body surface 131b is t25, the distance t25 may be 5% or more, 10% or more, or 20% or more of the thickness t24 of the wick sheet 130 described below. The distance t25 may be 45% or less, 40% or less, or 30% or less of the thickness t24 of the wick sheet 130.

[0256] The steam flow path section 150 including the steam passages 151 configured in this manner constitutes a part of the above-mentioned sealed space 103. As shown in Fig. 37, the steam flow path section 150 according to this embodiment is defined mainly by the lower sheet 110, the upper sheet 120, and the frame portion 132 and land portion 133 of the above-mentioned wick sheet 130. Each steam passage 151 has a relatively large flow path cross-sectional area so that the working steam 2a can pass through.

[0257] Here, in order to clarify the drawing, FIG. 37 shows the steam passages 151 and the like enlarged, and the number and arrangement of these steam passages 151 and the like differ from those in FIGS. 36, 40, and 41.

[0258] As shown in FIGS. 40 and 41 , support portions 139 that support the land portions 133 on the frame portion 132 are provided within the vapor channel portion 150. The support portions 139 support adjacent land portions 133. The support portions 139 are provided on both sides of the land portions 133 in the longitudinal direction (X direction). The support portions 139 may be formed so as not to interfere with the flow of the working vapor 2a diffusing through the vapor channel portion 150. In this case, the support portions 139 are disposed on the first main body surface 131a side of the wick sheet 130, and a space communicating with the vapor channel portion 150 is formed on the second main body surface 131b side. This allows the thickness of the support portions 139 to be thinner than the thickness of the wick sheet 130, preventing the vapor channel 151 from being divided in the X direction and the Y direction. However, this is not a limitation, and the support portions 139 may be disposed on the second main body surface 131b side. Furthermore, spaces communicating with the steam channel section 150 may be formed on both the surface of the support section 139 on the side of the first main body surface 131a and the surface on the side of the second main body surface 131b.

[0259] As shown in FIGS. 40 and 41, alignment holes 135 may be provided at the four corners of the wick sheet 130.

[0260] 36, the vapor chamber 100 may further include an injection section 104 for injecting the working liquid 2b into the sealed space 103 at one edge in the X direction. In the embodiment shown in FIG. 36, the injection section 104 is disposed on the evaporation region SR side. The injection section 104 has an injection flow path 37 formed in the wick sheet 130. The injection flow path 137 is formed on the second main body surface 131b side of the wick sheet 130 and is recessed from the second main body surface 131b side. After the vapor chamber 100 is completed, the injection flow path 137 is sealed. The injection flow path 137 is also connected to the vapor flow path section 150, and the working liquid 2b is injected into the sealed space 103 through the injection flow path 137. Depending on the arrangement of the liquid flow path section 160, the injection flow path 137 may be connected to the liquid flow path section 160.

[0261] In this embodiment, injection part 104 is provided on one edge of a pair of edges in the X direction of vapor chamber 100, but this is not limitative and injection part 104 can be provided at any position. In addition, injection part 104 may be formed in advance so as to protrude from one edge of vapor chamber 100 in the X direction.

[0262] As shown in FIGS. 37, 40, and 41, the liquid flow path portion 160 is provided on the second main body surface 131b of the wick sheet 130. The liquid flow path portion 160 is configured so that mainly the working liquid 2b passes through it. This liquid flow path portion 160 forms part of the sealed space 103 described above, and is in communication with the vapor flow path portion 150. The liquid flow path portion 160 is configured as a capillary structure (wick) for transporting the working liquid 2b to the evaporation region SR. In this embodiment, the liquid flow path portion 160 is provided on the second main body surface 131b of each land portion 133 of the wick sheet 130. The liquid flow path portion 160 may be formed over the entire second main body surface 131b of each land portion 133.

[0263] As shown in FIG. 43, the liquid flow path section 160 is an example of a groove assembly including a plurality of grooves. The liquid flow path section 160 has a plurality of main grooves 161, through which the working fluid 2b passes, that are arranged in parallel with one another, and a plurality of communication grooves 165 that communicate with the main grooves 161. The main grooves 161 of the liquid flow path section 160 are an example of first grooves. The communication grooves 165 of the liquid flow path section 160 are an example of second grooves. Note that in the example shown in FIG. 43, each land portion 133 includes six main grooves 161, but this is not limited to this. The number of main grooves 161 included in each land portion 133 is arbitrary and may be, for example, 3 to 20.

[0264] As shown in Fig. 43, each main groove 161 is formed to extend along the longitudinal direction (X direction) of the land portion 133. The multiple main grooves 161 are arranged parallel to one another. If the land portion 133 is curved in plan view, each main groove 161 may extend in a curved shape along the curved direction of the land portion 133. In other words, each main groove 161 does not necessarily have to be formed linearly, and does not necessarily have to extend parallel to the X direction.

[0265] The main grooves 161 have a smaller flow path cross-sectional area than the steam passages 151 of the steam flow path section 150 so that the working fluid 2b flows mainly by capillary action. The main grooves 161 are configured to transport the working fluid 2b condensed from the working steam 2a to the evaporation region SR. The main grooves 161 are arranged at intervals from one another in the width direction (Y direction).

[0266] The main grooves 161 are formed by etching from the second main body surface 131b of the wick sheet 130 in an etching process described below. As shown in FIG. 42, the main grooves 161 have curved wall surfaces 162. These wall surfaces 162 define the main grooves 161 and are curved in a shape that bulges toward the first main body surface 131a. In the cross section shown in FIG. 42, the radius of curvature of each wall surface 162 may be smaller than the radius of curvature of the second wall surface 154a of the steam passage 151.

[0267] 43, the width w23 of the main groove 161 may be, for example, not less than 2 μm and not more than 500 μm. The width w23 of the main groove 161 is the length in the direction perpendicular to the longitudinal direction of the land portion 133, which in this case is the dimension in the Y direction. The width w23 of the main groove 161 also refers to the dimension at the second main body surface 131b.

[0268] 42, the depth h21 of the main groove 161 may be, for example, 3 μm or more and 300 μm or less. The depth h21 of the main groove 161 is the distance measured from the second main body surface 131b in a direction perpendicular to the second main body surface 131b, which in this case is the dimension in the Z direction. The depth h21 refers to the depth of the main groove 161 at its deepest point.

[0269] As shown in FIG. 43 , each communication groove 165 extends in a direction different from the X direction. In this embodiment, each communication groove 165 is formed to extend in the Y direction, perpendicular to the main grooves 161. Some communication grooves 165 are arranged to connect adjacent main grooves 161 to each other. Other communication grooves 165 are arranged to connect the steam flow path section 150 (steam passage 151) to the main groove 161 closest to the steam flow path section 150. In other words, the communication groove 165 extends from the end of the land portion 133 in the Y direction to the main groove 161 adjacent to that end. In this way, the steam passage 151 of the steam flow path section 150 and the main groove 161 are connected to each other.

[0270] The communication groove 165 has a flow path cross-sectional area smaller than that of the vapor passage 151 of the vapor flow path portion 150 so that the working fluid 2b flows mainly by capillary action. The communication grooves 165 may be arranged at equal intervals in the longitudinal direction (X direction) of the land portion 133.

[0271] Like the main groove 161, the connection groove 165 is also formed by etching, and has wall surfaces (not shown) that are formed in a curved shape similar to that of the main groove 161. As shown in Fig. 43, the width w24 of the connection groove 165 (the dimension in the X direction) may be 5 µm or more and 300 µm or less. The depth of the connection groove 165 may be 3 µm or more and 300 µm or less.

[0272] The main stream groove 161 includes an intersection 166 that communicates with the communication groove 165. At the intersection 166, the main stream groove 161 and the communication groove 165 communicate in a T-shape. This prevents the communication groove 165 on the other side (e.g., the lower side in FIG. 43 ) from communicating with the main stream groove 161 at the intersection 166, where the main stream groove 161 communicates with the communication groove 165 on one side (e.g., the upper side in FIG. 43 ). This prevents the wall surface 162 of the main stream groove 161 from being cut out on both sides in the Y direction at the intersection 166, leaving one wall surface 162 intact. This allows the working fluid 2b in the main stream groove 161 to have a capillary action at the intersection 166 as well, preventing a decrease in the driving force of the working fluid 2b toward the evaporation region SR at the intersection 166.

[0273] As shown in Fig. 43, liquid convex rows 163 are provided between adjacent main grooves 161 of the liquid flow path section 160. Note that, in the example shown in Fig. 43, each land section 133 includes seven liquid convex rows 163, but this is not limited to this. The number of liquid convex rows 163 included in each land section 133 is arbitrary, and may be, for example, 3 to 20 rows.

[0274] As shown in Figure 43, each liquid convex row 163 is formed to extend along the longitudinal direction (X direction) of the land portion 133. The multiple liquid convex row 163 are arranged parallel to one another. If the land portion 133 is curved in plan view, each liquid convex row 163 may extend in a curved shape along the curvature direction of the land portion 133. In other words, each liquid convex row 163 does not necessarily have to be formed linearly, and does not necessarily have to extend parallel to the X direction. Each liquid convex row 163 is arranged at intervals from one another in the width direction (Y direction).

[0275] Each liquid convex portion row 163 includes a plurality of convex portions 164 (liquid flow path protrusions) arranged in the X direction. The convex portions 164 are provided within the liquid flow path portion 160, and protrude from the main stream grooves 161 and the communication grooves 165 to abut against the upper sheet 120. Each convex portion 164 is formed in a rectangular shape with the X direction as its longitudinal direction in a plan view. A main stream groove 161 is disposed between each of the convex portions 164 adjacent to each other in the Y direction. A communication groove 165 is disposed between each of the convex portions 164 adjacent to each other in the X direction. The communication groove 165 is formed to extend in the Y direction and connects the main stream grooves 161 adjacent to each other in the Y direction. This allows the working fluid 2b to move back and forth between these main stream grooves 161.

[0276] The protrusions 164 are portions that are not removed by etching in the etching process described below, and the material of the wick sheet 130 remains. In this embodiment, as shown in FIG. 43, the planar shape of the protrusions 164 is rectangular. The planar shape of the protrusions 164 corresponds to the shape of the wick sheet 130 at the position of the second main body surface 131b. The width w25 of the protrusions 164 may be, for example, 5 μm or more and 500 μm or less. The width w25 of the protrusions 164 refers to the value at the point where the width of the protrusions 164 is at its maximum.

[0277] The arrangement pitch of the convex portions 164 in the width direction (Y direction) of the convex portions 164 may be, for example, 7 μm or more and 1000 μm or less. Here, the arrangement pitch of the convex portions 164 refers to the distance between the center of a convex portion 164 in the Y direction and the center of an adjacent convex portion 164 in the Y direction, and refers to the distance measured in the Y direction.

[0278] In this embodiment, the convex portions 164 are arranged in a staggered (alternate) pattern. More specifically, the convex portions 164 of the liquid convex portion rows 163 adjacent to each other in the Y direction are arranged so as to be shifted from each other in the X direction. This shift amount may be half the arrangement pitch of the convex portions 164 in the X direction. Note that the arrangement of the convex portions 164 is not limited to a staggered pattern, and they may also be arranged in parallel. In this case, the convex portions 164 of the liquid convex portion rows 163 adjacent to each other in the Y direction are also aligned in the X direction.

[0279] The length L1 of the protrusions 164 may be uniform between the respective protrusions 164. The length L1 of the protrusions 164 is longer than the width w24 of the communication groove 165 (L1>w24). The length L1 of the protrusions 164 corresponds to the dimension of the protrusions 164 in the X direction, and means the maximum dimension in the X direction on the second main body surface 131b.

[0280] The materials constituting the lower sheet 110, the upper sheet 120, and the wick sheet 130 are not particularly limited as long as they have good thermal conductivity. The lower sheet 110, the upper sheet 120, and the wick sheet 130 may contain, for example, copper or a copper alloy. In this case, the thermal conductivity of each sheet 110, 120, and 130 can be increased, thereby improving the heat dissipation efficiency of the vapor chamber 100. Furthermore, when pure water is used as the working fluids 2a and 2b, corrosion can be prevented. However, other metal materials such as aluminum or titanium, or other metal alloy materials such as stainless steel, can also be used for these sheets 110, 120, and 130 as long as they can achieve the desired heat dissipation efficiency and prevent corrosion.

[0281] 37 may be, for example, 100 μm or more and 2000 μm or less. By making the thickness t21 of the vapor chamber 100 100 μm or more, the vapor channel portion 150 is properly secured, allowing the vapor chamber 100 to function properly. On the other hand, by making the thickness t21 2000 μm or less, the thickness t21 of the vapor chamber 100 can be prevented from becoming too thick.

[0282] The thickness t22 of the lower sheet 110 may be, for example, 25 μm or more and 500 μm or less. By setting the thickness t22 of the lower sheet 110 to 25 μm or more, the mechanical strength of the lower sheet 110 can be ensured. On the other hand, by setting the thickness t22 of the lower sheet 110 to 500 μm or less, an increase in the thickness t21 of the vapor chamber 100 can be prevented. Similarly, the thickness t23 of the upper sheet 120 may be set to the same as the thickness t22 of the lower sheet 110. The thickness t23 of the upper sheet 120 and the thickness t22 of the lower sheet 110 may be different.

[0283] The thickness t24 of the wick sheet 130 may be, for example, 50 μm or more and 1000 μm or less. By making the thickness t24 of the wick sheet 130 50 μm or more, the vapor channel portion 150 can be appropriately secured, allowing the wick sheet 130 to function appropriately as a vapor chamber 100. On the other hand, by making the thickness t24 1000 μm or less, the thickness t21 of the vapor chamber 100 can be prevented from becoming too thick.

[0284] Next, a method for manufacturing the vapor chamber 100 of this embodiment configured as described above will be described with reference to Figures 44 to 46. Note that Figures 44 to 46 show the same cross section as the cross section of Figure 37.

[0285] First, the process of manufacturing the wick sheet 130 will be described.

[0286] First, as shown in FIG. 44, in a preparation step, a flat metal material sheet M including a lower surface Ma and an upper surface Mb is prepared.

[0287] After the preparation step, in the etching step, the metal material sheet M is etched from the lower surface Ma and the upper surface Mb, as shown in FIG. 45, to form the vapor flow path portion 150 and the liquid flow path portion 160.

[0288] More specifically, a patterned resist film (not shown) is formed on the lower surface Ma and upper surface Mb of the metal material sheet M by photolithography. Subsequently, the lower surface Ma and upper surface Mb of the metal material sheet M are etched through openings in the patterned resist film. As a result, the lower surface Ma and upper surface Mb of the metal material sheet M are etched in a pattern, forming a vapor flow path portion 150 and a liquid flow path portion 160 as shown in FIG. 45. 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.

[0289] The etching may be performed simultaneously on the lower surface Ma and the upper surface Mb of the metal material sheet M. However, this is not limited to this, and the etching of the lower surface Ma and the upper surface Mb may be performed in separate steps. Furthermore, the vapor flow path portion 150 and the liquid flow path portion 160 may be formed by etching simultaneously, or may be formed in separate steps.

[0290] In the etching step, the lower surface Ma and the upper surface Mb of the metal material sheet M are etched to obtain a predetermined outer contour shape as shown in Figures 40 and 41. That is, the edges of the wick sheet 130 are formed.

[0291] In this manner, the wick sheet 130 according to this embodiment is obtained.

[0292] After the manufacturing process of the wick sheet 130, a joining process is performed in which the lower sheet 110, the upper sheet 120, and the wick sheet 130 are joined together as shown in Fig. 46. The lower sheet 110 and the upper sheet 120 may be formed from rolled material having a desired thickness.

[0293] More specifically, first, the lower sheet 110, the wick sheet 130, and the upper sheet 120 are laminated in this order. In this case, the first main body surface 131a of the wick sheet 130 is placed on the second lower sheet surface 110b of the lower sheet 110, and the first upper sheet surface 120a of the upper sheet 120 is placed on the second main body surface 131b of the wick sheet 130. At this time, the alignment holes 112 of the lower sheet 110, the alignment holes 135 of the wick sheet 130, and the alignment holes 122 of the upper sheet 120 are used to align the sheets 110, 120, and 130.

[0294] Next, the lower sheet 110, the wick sheet 130, and the upper sheet 120 are temporarily joined together. For example, these sheets 110, 120, and 130 may be temporarily joined together by spot resistance welding, or by laser welding.

[0295] Next, the lower sheet 110, the wick sheet 130, and the upper sheet 120 are permanently bonded together by diffusion bonding. More specifically, the frame portion 132 of the wick sheet 130 and the first main body surface 131a of each land portion 133 are diffusion bonded to the second lower sheet surface 110b of the lower sheet 110. Furthermore, the frame portion 132 of the wick sheet 130 and the second main body surface 131b of each land portion 133 are diffusion bonded to the first upper sheet surface 120a of the upper sheet 120. In this manner, the sheets 110, 120, and 130 are diffusion bonded together to form a sealed space 103 having a vapor flow path portion 150 and a liquid flow path portion 160 between the lower sheet 110 and the upper sheet 120.

[0296] After the joining step, the hydraulic fluid 2 b is injected into the sealed space 103 from the injection part 104 .

[0297] Thereafter, the above-mentioned injection flow path 137 is sealed. For example, the injection portion 104 may be partially melted to seal the injection flow path 137. This blocks communication between the sealed space 103 and the outside, seals the working fluid 2b in the sealed space 103, and prevents the working fluid 2b in the sealed space 103 from leaking to the outside.

[0298] In this manner, the vapor chamber 100 according to this embodiment is obtained.

[0299] Next, a method for operating the vapor chamber 100, that is, a method for cooling the electronic device D, will be described.

[0300] The vapor chamber 100 obtained as described above is installed in the housing H of an electronic device E such as a mobile terminal, and an electronic device D, such as a CPU, which is a device to be cooled, is attached to the second upper sheet surface 120b of the upper sheet 120. Alternatively, the vapor chamber 100 is attached to the electronic device D. Due to its surface tension, the working fluid 2b in the sealed space 103 adheres to the wall surfaces of the sealed space 103, i.e., the first wall surface 153a and the second wall surface 154a of the vapor passage 151, the wall surface 162 of the main groove 161 of the liquid flow path section 160, and the wall surface of the communication groove 165. The working fluid 2b may also adhere to a portion of the second lower sheet surface 110b of the lower sheet 110 exposed to the vapor passage 151. The working fluid 2b may also adhere to a portion of the first upper sheet surface 120a of the upper sheet 120 exposed to the vapor passage 151, the main groove 161, and the communication groove 165.

[0301] In this state, when the electronic device D generates heat, the working fluid 2b present in the evaporation region SR (see Figures 40 and 41) receives heat from the electronic device D. The received heat is absorbed as latent heat, and the working fluid 2b evaporates (vaporizes), generating working vapor 2a. Most of the generated working vapor 2a diffuses within the vapor passages 151 that form the sealed space 103 (see the solid arrows in Figure 40). The working vapor 2a in each vapor passage 151 leaves the evaporation region SR, and most of the working vapor 2a is transported to the condensation region CR (the right-hand portion in Figures 40 and 41), which has a relatively low temperature. In the condensation region CR, the working vapor 2a is cooled by radiating heat mainly to the lower sheet 110. The heat received by the lower sheet 110 from the working vapor 2a is transferred to the outside air via the housing member Ha (see Figure 37).

[0302] The working vapor 2a radiates heat to the lower sheet 110 in the condensation region CR, and condenses in the evaporation region SR, losing the absorbed latent heat, to generate working fluid 2b. The generated working fluid 2b adheres to the first wall surface 153a and the second wall surface 154a of each vapor passage 151, the second lower sheet surface 110b of the lower sheet 110, and the first upper sheet surface 120a of the upper sheet 120. Here, the working fluid 2b continues to evaporate in the evaporation region SR. Therefore, the working fluid 2b in the region of the liquid flow path section 160 other than the evaporation region SR (i.e., the condensation region CR) is transported toward the evaporation region SR by the capillary action of each mainstream groove 161 (see the dashed arrows in FIG. 40). As a result, the working fluid 2b adhering to each vapor passage 151, the second lower sheet surface 110b, and the first upper sheet surface 120a moves to the liquid flow path section 160, passes through the communication grooves 165, and enters the mainstream grooves 161. In this way, the working fluid 2b is filled into each of the main grooves 161 and each of the communication grooves 165. Therefore, the filled working fluid 2b obtains a driving force toward the evaporation region SR due to the capillary action of each of the main grooves 161, and is smoothly transported toward the evaporation region SR.

[0303] In the liquid flow path section 160, each mainstream groove 161 communicates with the adjacent other mainstream groove 161 via the corresponding communication groove 165. This allows the working fluid 2b to flow between adjacent mainstream grooves 161, preventing the occurrence of dryout in the mainstream grooves 161. This imparts capillary action to the working fluid 2b in each mainstream groove 161, allowing the working fluid 2b to be smoothly transported toward the evaporation region SR.

[0304] The working fluid 2b that reaches the evaporation region SR receives heat from the electronic device D and evaporates again. The working vapor 2a that has evaporated from the working fluid 2b passes through the communication groove 165 in the evaporation region SR, moves to the vapor passages 151 with large flow path cross-sectional areas, and diffuses within each vapor passage 151. In this way, the working fluids 2a and 2b circulate within the sealed space 103 while repeatedly changing phases, i.e., evaporating and condensing, and transport and release heat from the electronic device D. As a result, the electronic device D is cooled.

[0305] In the evaporation region SR, the working vapor 2a generated from the working fluid 2b moves from the liquid flow path section 160 toward the vapor passage 151. At this time, the working vapor 2a flows from the main groove 161 through the communication groove 165 adjacent to the convex portion 164 on the outer side of each liquid flow path section 160 in the width direction, and flows out into the vapor passage 151.

[0306] In general, the pressure gradient of the working vapor 2a in the thickness direction (Z direction) is large in the portion of the vapor passage 151 on the second body surface 131b side, and the pressure gradient of the working vapor 2a in the thickness direction (Z direction) is small in the portion of the vapor passage 151 on the first body surface 131a side. In this embodiment, as shown in FIG. 47 , the protrusion 155 is located closer to the second body surface 131b than the intermediate position Pz between the first body surface 131a and the second body surface 131b. Therefore, when the vaporized working vapor 2a spreads from the liquid flow path section 160 to the vapor passage 151, the pressure gradient in the vertical direction of the protrusion 155 becomes large near the protrusion 155. The pressure difference between the portion above and below the protrusion 155 can become large. The portion above the protrusion 155 corresponds to the portion on the second wall surface 154a side, and the portion below the protrusion 155 corresponds to the portion on the first wall surface 153a side. Therefore, the air pressure of the working steam 2a in the portion above the protrusion 155 can be made sufficiently greater than the air pressure of the working steam 2a in the portion below the protrusion 155, and the working steam 2a can easily overcome the protrusion 155. This allows the working steam 2a to easily flow from the portion above the protrusion 155 to the portion below the protrusion 155. As a result, the protrusion 155 is less likely to obstruct the passage of the working steam 2a, and the working steam 2a can be smoothly diffused from the protrusion 155 toward the portion below the protrusion 155.

[0307] In this embodiment, the first wall surface end 153b of the first wall surface 153a is located inside the vapor channel portion 150 relative to the protrusion 155 in a plan view. Therefore, the first wall surface 153a is formed to face inward of the vapor channel 151. As a result, the working vapor 2a that has traveled from the upper portion of the protrusion 155 to the lower portion thereof is guided along the first wall surface 153a toward the inside of the vapor channel 151 in the width direction (Y direction). As a result, the working vapor 2a is smoothly diffused inside the vapor channel 151, thereby improving the cooling capacity of the vapor chamber 100. The radius of curvature of the first wall surface 153a may gradually increase toward the first wall surface end 153b. Therefore, as the radius of curvature increases, the obstruction to the flow of the working vapor 2a toward the first main body surface 131a increases. This allows the working vapor 2a to be diffused more smoothly inside the vapor channel 151.

[0308] Meanwhile, in the condensation region CR, the working fluid 2b generated from the working vapor 2a moves from the vapor passage 151 toward the liquid flow path section 160. At this time, the working fluid 2b passes through the communication grooves 165 adjacent to the convex portions 164 on the outer sides of each liquid flow path section 160 in the width direction, and enters the mainstream grooves 161.

[0309] In this embodiment, first wall surface end portion 153b of first wall surface 153a is located inside steam channel portion 150 relative to protrusion 155 in plan view. Therefore, working fluid 2b flowing through steam channel 151 is guided along first wall surface 153a to liquid channel portion 160. As a result, working fluid 2b smoothly enters liquid channel portion 160. Furthermore, because working fluid 2b can easily climb over protrusion 155, protrusion 155 is less likely to obstruct the passage of working fluid 2b, and working fluid 2b can smoothly flow from protrusion 155 into liquid channel portion 160.

[0310] Furthermore, in this embodiment, the protrusion 155 is located closer to the second main body surface 131b than the intermediate position Pz. Therefore, the radius of curvature of the second wall surface 154a can be made smaller than the radius of curvature of the first wall surface 153a. This enhances the capillary action of the second wall surface 154a, allowing the working liquid 2b to smoothly flow into the liquid flow path portion 160. Furthermore, the enhanced capillary action also enhances the retention of the working liquid 2b by the second wall surface 154a. This increases the amount of working liquid 2b transported to the evaporation region SR.

[0311] In addition, in this embodiment, the first wall surface end 153b of the first wall surface 153a is located inside the steam flow path section 150 more than the protrusion portion 155 in a planar view, so that shape defects at the widthwise end of the land portion 133 can be easily confirmed in a planar view.

[0312] Furthermore, in this embodiment, the first wall surface 153a is curved in a curved shape toward the liquid flow path portion 160, so that the volume of the vapor path 151 is increased, and the cooling capacity of the vapor chamber 100 can be improved.

[0313] The present invention is not limited to the above-described embodiments and modifications, and can be embodied by modifying the components within the scope of the gist of the present invention. Furthermore, various inventions can be created by appropriately combining the multiple components disclosed in the above-described embodiments and modifications. Some components may be omitted from all the components shown in the embodiments and modifications.

Claims

1. A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; a plurality of first grooves provided on the first main body surface and communicating with the through-space, the plurality of first grooves extending in a first direction; The through space extends in a first direction in a plan view, A main body sheet for a vapor chamber, wherein when viewed in a cross section perpendicular to the first direction, the through space has a first opening located on the first main body surface and a second opening located on the second main body surface, and the second opening extends from a region overlapping the first opening in a planar view to a position overlapping the first groove in a planar view.

2. When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first body surface and defining the first opening, and a second spatial recess provided in the second body surface and defining the second opening, the second spatial recess communicating with the first spatial recess, the first spatial recess includes a pair of concavely curved first wall surfaces, the second spatial recess includes a pair of concavely curved second wall surfaces, The first wall surface and the second wall surface corresponding to each other are connected by a wall surface protrusion that protrudes toward the inside of the through space, A main body sheet for a vapor chamber as described in claim 1, wherein when viewed in a cross section perpendicular to the first direction, the second spatial recess includes a flat surface formed flatly that connects the corresponding second wall surface and the wall surface protrusion portion.

3. When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first body surface and defining the first opening, and a second spatial recess provided in the second body surface and defining the second opening, the second spatial recess communicating with the first spatial recess, the first spatial recess includes a pair of first wall surfaces that are concavely curved, the second spatial recess includes a pair of concavely curved second wall surfaces, The first wall surface and the second wall surface corresponding to each other are connected by a wall surface protrusion that protrudes toward the inside of the through space, When viewed in a cross section perpendicular to the first direction, the second spatial recess includes a convex surface connecting the second wall surface and the wall surface protrusion corresponding to each other, The main body sheet for a vapor chamber according to claim 1 , wherein the convex surface includes a spatial convex portion that extends in the first direction and protrudes toward the second main body surface.

4. The main body sheet for a vapor chamber according to claim 3 , wherein the convex surface includes a plurality of the spatial convex portions spaced apart from each other.

5. When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first body surface and defining the first opening, and a second spatial recess provided in the second body surface and defining the second opening, the second spatial recess communicating with the first spatial recess, the first spatial recess includes a pair of first wall surfaces that are convexly curved, The main body sheet for a vapor chamber according to claim 1 , wherein the second spatial recess includes a pair of second wall surfaces that are concavely curved.

6. A main body sheet for a vapor chamber described in any one of claims 1 to 5, wherein, when viewed in a cross section perpendicular to the first direction, the second opening extends from a region overlapping the first opening in a planar view to a position overlapping the first groove in a planar view on both sides of the first opening.

7. a frame body portion formed in a frame shape in a plan view and extending from the first main body surface to the second main body surface, the frame body portion defining the through space; a land portion provided on an inner side of the frame portion, the land portion extending in the first direction and extending from the first main body surface to the second main body surface, the first opening and the second opening are located between the frame portion and the land portion, the first groove is located on the first body surface of the land portion; A main body sheet for a vapor chamber described in any one of claims 1 to 6, wherein when viewed in a cross section perpendicular to the first direction, the second opening extends from a region overlapping the first opening in a planar view to a position overlapping the first groove located in the land portion in a planar view, and extends further outward than the first opening toward the outside of the frame portion.

8. A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; The through space extends in a first direction in a plan view, When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first main body surface and a second spatial recess provided in the second main body surface and communicating with the first spatial recess, the first spatial recess includes a pair of first wall surfaces, the second spatial recess includes a pair of second wall surfaces, one of the first wall surfaces of the first spatial recess and the corresponding second wall surface of the second spatial recess are connected by a first wall surface protrusion, The first wall surface protrusion protrudes toward the inside of the through-space, the first wall surface protrusion is disposed offset from an intermediate position between the first main body surface and the second main body surface in a normal direction of the first main body surface, A main body sheet for a vapor chamber, in which the first wall surface located on the opposite side of the first wall surface protrusion of the first spatial recess and the corresponding second wall surface of the second spatial recess are formed in a continuously concave shape from the first wall surface to the second wall surface.

9. the through space has a first opening located in the first body surface and defined by the first spatial recess, and a second opening located in the second body surface and defined by the second spatial recess; The main body sheet for a vapor chamber according to claim 8 , wherein the center of the first opening is offset from the center of the second opening when viewed in a cross section perpendicular to the first direction.

10. A frame body portion formed in a frame shape in a plan view; a land portion provided on the inside of the frame body portion, the land portion extending in the first direction and defining the through-space between the frame body portion and the land portion; A main body sheet for a vapor chamber as described in claim 9, wherein when the width of the land portion is w1, the deviation between the center of the first opening and the center of the second opening is 0.05 mm to (0.8 x w1) mm.

11. The device further comprises a plurality of first grooves provided on the first body surface and communicating with the through space; The main body sheet for a vapor chamber according to any one of claims 8 to 10, wherein the first wall surface protrusion is positioned closer to the first main body surface than the intermediate position.

12. A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; The through space extends in a first direction in a plan view, When viewed in a cross section perpendicular to the first direction, the through space has a first spatial recess provided in the first main body surface and a second spatial recess provided in the second main body surface and communicating with the first spatial recess, the first spatial recess includes a pair of first wall surfaces, the second spatial recess includes a pair of second wall surfaces, one of the first wall surfaces of the first spatial recess and the corresponding second wall surface of the second spatial recess are connected by a first wall surface protrusion, The first wall surface protrusion protrudes toward the inside of the through-space, the first wall surface protrusion is disposed offset from an intermediate position between the first main body surface and the second main body surface in a normal direction of the first main body surface, the through space has a first opening located in the first body surface and defined by the first spatial recess, and a second opening located in the second body surface and defined by the second spatial recess; A main body sheet for a vapor chamber, wherein the center of the first opening is positioned offset from the center of the second opening when viewed in a cross section perpendicular to the first direction.

13. a frame body portion formed in a frame shape in a plan view; a land portion provided on the inside of the frame body portion, the land portion extending in the first direction and defining the through-space between the frame body portion and the land portion; A main body sheet for a vapor chamber as described in claim 12, wherein when the width of the land portion is w1, the deviation between the center of the first opening and the center of the second opening is 0.05 mm to (0.8 x w1) mm.

14. The device further includes a plurality of first grooves provided on the first body surface and communicating with the through-space, The main body sheet for a vapor chamber according to claim 12 or 13, wherein the first wall surface protrusion is positioned closer to the first main body surface than the intermediate position.

15. the first wall surface located on the opposite side of the first wall surface protrusion of the first spatial recess and the corresponding second wall surface of the second spatial recess are connected by a second wall surface protrusion, The second wall surface protrusion protrudes toward the inside of the through-space, The main body sheet for a vapor chamber according to claim 14 , wherein the second wall surface protrusion is positioned offset from an intermediate position between the first main body surface and the second main body surface in the normal direction.

16. The main body sheet for a vapor chamber according to claim 15 , wherein the second wall surface protrusion is positioned closer to the first main body surface than the intermediate position.

17. A main body sheet for a vapor chamber in which a working fluid is sealed, a first body surface; a second body surface provided on the opposite side to the first body surface; a through space extending from the first body surface to the second body surface; The through space extends in a first direction in a plan view, When viewed in a cross section perpendicular to the first direction, the through-space has a first spatial recess provided in the first body surface, a second spatial recess provided in the second body surface and communicating with the first spatial recess, and a third spatial recess provided in the second body surface, the third spatial recess being located on both sides of the second spatial recess and communicating with the second spatial recess, the second spatial recess includes a pair of second wall surfaces, the third spatial recess includes a third wall surface, Each of the second wall surfaces of the second spatial recesses and the corresponding third wall surface of the third spatial recesses are connected by a third wall surface protrusion, A main body sheet for a vapor chamber, wherein the third wall surface protrusion protrudes toward the second main body surface.

18. A main body sheet for a vapor chamber, a first body surface; a second body surface located opposite the first body surface; a through space penetrating the first body surface and the second body surface; a plurality of first grooves provided on the second body surface and communicating with the through-space; The through space has a curved first wall surface located on the first body surface side and a curved second wall surface located on the second body surface side, The first wall surface and the second wall surface meet at a protrusion formed to protrude into the through space, the protrusion is located closer to the second body surface than an intermediate position between the first body surface and the second body surface, the first wall has a first wall end on the first body surface side; A main body sheet for a vapor chamber, wherein the first wall end is located inside the through space relative to the protrusion in a plan view.

19. the second wall has a second wall end on the second body surface side; A main body sheet for a vapor chamber as described in claim 18, wherein when the distance between the second wall surface end and the protrusion portion in the width direction of the through space is Lp and the distance between the second wall surface end and the first wall surface end is Ls, the distance Ls is 1.05 times or more and 2 times or less of the distance Lp.

20. The first grooves are arranged in parallel with one another, A row of convex portions is provided between the adjacent first grooves, Each of the projection rows has a plurality of projections, the second wall has a second wall end on the second body surface side; A main body sheet for a vapor chamber as described in claim 18, wherein when the distance between the second wall end and the first wall end is Ls, the distance Ls is 1.1 times or more and 10 times or less the width of the convex portion.

21. The first sheet, A second seat; A vapor chamber comprising: a main body sheet for a vapor chamber according to any one of claims 1 to 20, interposed between the first sheet and the second sheet.

22. Housing and an electronic device contained within the housing; 22. An electronic device comprising: a vapor chamber according to claim 21 in thermal contact with the electronic device.

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