Vapor chambers, electronic devices and metal sheets for vapor chambers

Abstract

To provide a vapor chamber and a metal sheet for the vapor chamber that enable deaeration from the vapor chamber and injection of a hydraulic fluid into the vapor chamber in a short time in manufacturing the vapor chamber.SOLUTION: A vapor chamber comprises a first metal sheet and a second metal sheet provided on the first metal sheet. A plurality of vapor channel recesses, through which vapor of a hydraulic fluid passes, are formed in at least one of the first metal sheet and the second metal sheet, and a liquid channel part, through which the hydraulic fluid in a liquid state passes, is formed in at least one of the first metal sheet and the second metal sheet. An injection channel recess, from which the liquid hydraulic fluid is injected, is formed in at least one of the first metal sheet and the second metal sheet. A width of the injection channel recess is larger than that of a lower vapor passage of the vapor channel recess.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Devices that generate heat, such as central processing units (CPUs) used in mobile devices such as mobile terminals and tablet terminals, are cooled by heat dissipation members such as heat pipes (see, for example, Patent Document 1). In recent years, in order to make mobile terminals thinner, there has been a demand for thinner heat dissipation members, and vapor chambers that can be made thinner than heat pipes have been developed. A working fluid is sealed inside the vapor chamber, and this working fluid absorbs the heat of the device and releases it to the outside, thereby cooling the device.

[0003] More specifically, the working fluid in the vapor chamber receives heat from the device in a portion (evaporation portion) close to the device and evaporates into vapor, and the vapor then moves to a position away from the evaporation portion, where it is cooled and condenses into liquid. A capillary structure (wick) is provided in the vapor chamber as a liquid flow path, and the liquefied working fluid passes through this liquid flow path and is transported to the evaporation portion, where it receives heat again and evaporates. In this way, the working fluid circulates through the vapor chamber while repeatedly changing phases, i.e., evaporating and condensing, thereby transferring heat from the device and increasing heat dissipation efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-50682 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a flat heat exchanger such as a vapor chamber, an injection path is provided in the metal sheet for injecting the working liquid after degassing. However, if the width of the injection path is narrower than the steam passage or the groove of the wick, as in the sheet-type heat pipe described in Patent Document 1, for example, it takes time to degas the vapor chamber and inject the working liquid into the vapor chamber, which reduces workability.

[0006] The present invention has been made in consideration of these points, and aims to provide a vapor chamber, electronic device, and metal sheet for a vapor chamber that enables degassing the vapor chamber and injecting working fluid into the vapor chamber in a short period of time when manufacturing the vapor chamber. [Means for solving the problem]

[0007] The present invention relates to A vapor chamber containing a hydraulic fluid, A first metal sheet; a second metal sheet laminated to the first metal sheet; At least one of the first metal sheet and the second metal sheet is formed with a vapor flow path recess including a plurality of vapor paths through which the vapor of the working fluid passes; At least one of the first metal sheet and the second metal sheet is formed with a liquid flow path portion through which the liquid working fluid passes, At least one of the first metal sheet and the second metal sheet is formed with an injection flow path recess for injecting the liquid working fluid, a vapor chamber, the width of the injection channel recess being greater than the width of the vapor passage; to provide.

[0008] In the above-mentioned vapor chamber, A plurality of support columns are provided protruding from the injection channel recess. This may be done.

[0009] In addition, in the vapor chamber described above, A crimping region is formed in the injection channel recess, and the crimping region has a plurality of protrusions. This may be done.

[0010] In addition, in the vapor chamber described above, The width of the injection channel recess is 1.5 times or more the width of the steam passage. This may be done.

[0011] In addition, in the vapor chamber described above, The depth of the injection channel recess is greater than the depth of the steam passage. This may be done.

[0012] In addition, in the vapor chamber described above, The liquid flow path portion has a plurality of main grooves extending parallel to each other and a communication groove connecting adjacent main grooves. This may be done.

[0013] In addition, in the vapor chamber described above, a protrusion is formed so as to be surrounded by the main groove and the communication groove, and a plurality of the protrusions are arranged in a staggered pattern in a plan view; This may be done.

[0014] In addition, in the vapor chamber described above, The second metal sheet is provided on the first metal sheet. This may be done.

[0015] In addition, in the vapor chamber described above, Further comprising a third metal sheet interposed between the first metal sheet and the second metal sheet, the vapor flow path recess is formed in one of the first metal sheet and the second metal sheet, and the liquid flow path portion is formed in the other of the first metal sheet and the second metal sheet; The third metal sheet is provided with a communication portion that communicates the steam flow path recess and the liquid flow path portion. This may be done.

[0016] The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of: A vapor chamber containing a hydraulic fluid, A first metal sheet; a second metal sheet laminated to the first metal sheet; a third metal sheet interposed between the first metal sheet and the second metal sheet; The third metal sheet includes a first surface provided on a side of the first metal sheet and a second surface provided on a side of the second metal sheet, At least one of the first surface and the second surface of the third metal sheet is formed with a steam flow path portion including a plurality of steam passages through which the vapor of the working fluid passes, A liquid flow path portion through which the liquid hydraulic fluid passes is formed on at least one of the first surface and the second surface of the third metal sheet, An injection flow path portion for injecting the liquid working fluid is formed on at least one of the first surface and the second surface of the third metal sheet, A vapor chamber, wherein the width of the injection channel portion is greater than the width of the vapor passage. to provide.

[0017] The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of: Housing and a device contained within the housing; and an electronic device comprising: a vapor chamber as described above in thermal contact with the device; to provide.

[0018] The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of: A metal sheet for a vapor chamber for a vapor chamber in which a working fluid is sealed, The first page and A second surface provided on the opposite side to the first surface, a vapor flow passage recess including a plurality of vapor passages through which the vapor of the working fluid passes is formed in the first surface; a metal sheet for a vapor chamber, the metal sheet having a first surface formed with an injection flow path recess for injecting the liquid working fluid, the width of the injection flow path recess being wider than the width of the vapor passage; to provide. Effect of the Invention

[0019] According to the present invention, when manufacturing the vapor chamber, the degassing operation within the vapor chamber and the injection of the working fluid into the vapor chamber can be performed in a short time. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic perspective view illustrating an electronic device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a top view showing the vapor chamber according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view of the vapor chamber shown in FIG. 2 taken along line AA. [Figure 4] FIG. 4 is a top view showing the lower metal sheet of the vapor chamber of FIG. [Diagram 5] FIG. 5 is a bottom view showing the upper metal sheet of the vapor chamber of FIG. [Figure 6] FIG. 6 is an enlarged top view of the lower injection projection of the lower metal sheet of FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line BB of the lower injection protrusion of the lower metal sheet of FIG. [Figure 8] FIG. 8 is an enlarged top view showing the liquid flow path portion of FIG. [Figure 9] FIG. 9 is a cross-sectional view showing the cross section taken along line CC in FIG. 8 with an upper metal sheet added. [Figure 10] FIG. 10 is an enlarged top view showing a modification of the liquid flow path portion of FIG. [Figure 11]11(a) to (c) are diagrams showing a first half of a manufacturing method for a vapor chamber according to the first embodiment of the present invention. [Figure 12] 12(a) to 12(c) are diagrams showing a second half of the manufacturing method for the vapor chamber according to the first embodiment of the present invention. [Figure 13] FIG. 13 is a diagram showing a modified example (modification 1) of the vapor chamber in FIG. [Figure 14] FIG. 14 is a diagram showing another modified example (modified example 2) of the vapor chamber in FIG. [Figure 15] FIG. 15 is a diagram showing another modified example (Modification 3) of the lower injection protrusion of FIG. [Figure 16] FIG. 16 is a diagram showing another modified example (Modification 4) of the lower injection protrusion of FIG. [Figure 17] FIG. 17 is a cross-sectional view showing a vapor chamber in the second embodiment of the present invention. [Figure 18] FIG. 18 is a bottom view of the upper metal sheet of FIG. [Figure 19] FIG. 19 is a top view of the intermediate metal sheet of FIG. [Figure 20] FIG. 20 is a cross-sectional view showing a vapor chamber in the third embodiment of the present invention. [Figure 21] FIG. 21 is a top view of the intermediate metal sheet of FIG. [Figure 22] FIG. 22 is a cross-sectional view showing a vapor chamber in the fourth embodiment of the present invention. [Figure 23] FIG. 23 is a bottom view of the intermediate metal sheet of FIG. [Figure 24] FIG. 24 is a top view of the intermediate metal sheet of FIG. [Diagram 25] FIG. 25 is a cross-sectional view showing a modified example of the vapor chamber of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to this specification, the scale and the aspect ratio are appropriately changed and exaggerated from those of the actual objects for the convenience of illustration and understanding.

[0022] In addition, terms such as "parallel," "orthogonal," and "same," which specify the shape, geometric conditions, and physical characteristics and their degree, as well as the length, angle, and physical characteristic values ​​used in this specification, are to be interpreted without being bound by strict meanings, but including the range in which similar functions can be expected. Furthermore, in the drawings, the shapes of multiple parts that can be expected to have similar functions are regularly depicted for clarity, but the shapes of the parts may be different from each other within the range in which the functions can be expected without being bound by strict meanings. In addition, in the drawings, the boundary lines indicating the joint surfaces between members are shown as simple straight lines for convenience, but the shape of the boundary line is not limited to being a strict straight line, and is arbitrary within the range in which the desired joint performance can be expected.

[0023] (First embodiment) 1 to 16, a vapor chamber, an electronic device, and a metal sheet for a vapor chamber according to a first embodiment of the present invention will be described. The vapor chamber 1 in this embodiment is a device mounted on an electronic device E in order to cool a device D, which is a heat generating body housed in the electronic device E. Examples of the device D include electronic devices (cooled devices) that generate heat, such as central processing units (CPUs), light-emitting diodes (LEDs), and power semiconductors used in mobile devices such as portable terminals and tablet terminals.

[0024] Here, first, an electronic device E equipped with the vapor chamber 1 according to the present embodiment will be described by taking a tablet terminal as an example. As shown in FIG. 1, the electronic device E (tablet terminal) includes a housing H, a device D accommodated 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 accommodated in the housing H and arranged so as to be in thermal contact with the device D. This allows the vapor chamber 1 to receive heat generated in the device D when the electronic device E is used. The heat received by the vapor chamber 1 is released to the outside of the vapor chamber 1 via the working liquid 2 described later. In this way, the device D is effectively cooled. When the electronic device E is a tablet terminal, the device D corresponds to a central processing unit or the like.

[0025] Next, a description will be given of the vapor chamber 1 in this embodiment. The vapor chamber 1 has a sealed space 3 filled with a working liquid 2, and the working liquid 2 in the sealed space 3 repeatedly changes phase, thereby effectively cooling the device D of the electronic device E described above.

[0026] The vapor chamber 1 is generally formed in a thin flat plate shape. The planar shape of the vapor chamber 1 is arbitrary, but may be a rectangle as shown in FIG. 2. In this case, the vapor chamber 1 has four linear outer edges 1a, 1b forming an out-of-plane contour. Two of the outer edges 1a are formed along a first direction X described later, and the remaining two outer edges 1b are formed along a second direction Y described later. The planar shape of the vapor chamber 1 may be, for example, a rectangle with one side being 1 cm and the other side being 3 cm, or a square with one side being 15 cm, and the planar dimensions of the vapor chamber 1 are arbitrary. In addition, the planar shape of the vapor chamber 1 is not limited to a rectangle, and may be any shape, such as a circle, an ellipse, an L-shape, or a T-shape.

[0027] As shown in FIG. 2 and FIG. 3, the vapor chamber 1 includes a lower metal sheet 10 (first metal sheet or second metal sheet, metal sheet for vapor chamber) and an upper metal sheet 20 (second metal sheet or first metal sheet, metal sheet for vapor chamber) laminated on the lower metal sheet 10. In this embodiment, the upper metal sheet 20 is provided on the lower metal sheet 10. The lower metal sheet 10 has an upper surface 10a (first surface) and a lower surface 10b (second surface) provided on the opposite side to the upper surface 10a. The upper metal sheet 20 has a lower surface 20a (surface on the side of the lower metal sheet 10) superimposed on the upper surface 10a (surface on the side of the upper metal sheet 20) of the lower metal sheet 10, and an upper surface 20b provided on the opposite side to the lower surface 20a. A device D, which is an object to be cooled, is attached to the lower surface 10b of the lower metal sheet 10 (particularly, the lower surface of an evaporation portion 11 described later).

[0028] A sealed space 3 filled with a working fluid 2 is formed between the lower metal sheet 10 and the upper metal sheet 20. In this embodiment, the sealed space 3 has a vapor flow path portion 80 (a lower vapor flow path recess 12 and an upper vapor flow path recess 21 described later) through which mainly the vapor of the working fluid 2 passes, and a liquid flow path portion 30 through which mainly the liquid working fluid 2 passes. Examples of the working fluid 2 include pure water, ethanol, methanol, and acetone.

[0029] The lower metal sheet 10 and the upper metal sheet 20 are joined by diffusion bonding, which will be described later. In the embodiment shown in Fig. 2 and Fig. 3, the lower metal sheet 10 and the upper metal sheet 20, except for the injection part 4, which will be described later, are both formed in a rectangular shape in a plan view, but this is not limited thereto. Here, the plan view refers to a state in which the vapor chamber 1 is viewed from a direction perpendicular to the surface that receives heat from the device D (the lower surface 10b of the lower metal sheet 10) and the surface that releases the received heat (the upper surface 20b of the upper metal sheet 20), and corresponds to, for example, a state in which the vapor chamber 1 is viewed from above (see Fig. 2) or a state in which it is viewed from below.

[0030] When the vapor chamber 1 is installed inside a mobile terminal, the vertical relationship between the lower metal sheet 10 and the upper metal sheet 20 may be lost depending on the posture of the mobile terminal. However, in this embodiment, for convenience, the metal sheet that receives heat from device D will be referred to as the lower metal sheet 10, and the metal sheet that dissipates the received heat will be referred to as the upper metal sheet 20, and the description will be given with the lower metal sheet 10 positioned on the lower side and the upper metal sheet 20 positioned on the upper side.

[0031] As shown in FIG. 2, the vapor chamber 1 further includes an injection section 4 for injecting the working fluid 2 into the sealed space 3 at one of a pair of ends in the first direction X. The injection section 4 includes a lower injection protrusion 16 protruding laterally from an end face of the lower metal sheet 10 (a surface corresponding to the outer edge 1b in FIG. 2) and an upper injection protrusion 25 protruding laterally from an end face of the upper metal sheet 20 (a surface corresponding to the outer edge 1b in FIG. 2). Of these, a lower injection flow path recess 17 (injection flow path recess) is formed on the upper surface of the lower injection protrusion 16 (a surface corresponding to the upper surface 10a of the lower metal sheet 10) (see FIG. 4). On the other hand, no recess is formed on the lower surface of the upper injection protrusion 25 (a surface corresponding to the lower surface 20a of the upper metal sheet 20), and the upper injection protrusion 25 has the same thickness as the metal material sheet before processing (metal material sheet M described later) (see FIG. 5). The inner end (end on the sealed space 3 side) of the lower injection flow path recess 17 communicates with the lower steam flow path recess 12, and the outer end (end on the opposite side of the sealed space 3) of the lower injection flow path recess 17 opens outward. When the lower metal sheet 10 and the upper metal sheet 20 are joined, the lower injection flow path recess 17 and the upper injection protrusion 25 form an injection flow path for the working fluid 2 together. The working fluid 2 passes through the injection flow path and is injected into the sealed space 3. In this embodiment, an example is shown in which the injection part 4 is provided at one end of a pair of ends in the first direction X of the vapor chamber 1, but this is not limited to this and the injection part 4 can be provided at any position. In addition, two or more injection parts 4 may be provided.

[0032] Next, a description will be given of the configuration of the lower metal sheet 10. As shown in Fig. 4, the lower metal sheet 10 has an evaporation section 11 in which the working fluid 2 evaporates to generate steam, and a lower steam flow path recess 12 (first steam flow path section) that is provided on the upper surface 10a and formed in a rectangular shape in a plan view. Of these, the lower steam flow passage recess 12 constitutes a part of the above-mentioned sealed space 3, and is configured so that the steam generated in the evaporation section 11 mainly passes through it.

[0033] The evaporation section 11 is disposed in the lower vapor flow recess 12, and the vapor in the lower vapor flow recess 12 diffuses away from the evaporation section 11, and most of the vapor is transported toward the peripheral portion having a relatively low temperature. The evaporation section 11 is a portion where the working liquid 2 in the sealed space 3 evaporates upon receiving heat from the device D attached to the lower surface 10b of the lower metal sheet 10. For this reason, the term evaporation section 11 is used as a concept that is not limited to the portion overlapping the device D, but also includes a portion where the working liquid 2 can evaporate even if it does not overlap the device D. Here, the evaporation section 11 can be provided at any position on the lower metal sheet 10, but an example where it is provided at the center of the lower metal sheet 10 is shown in FIG. 2 and FIG. 4. In this case, the operation of the vapor chamber 1 can be stabilized regardless of the posture of the mobile terminal on which the vapor chamber 1 is installed.

[0034] In this embodiment, as shown in FIG. 3 and FIG. 4, a plurality of lower flow passage walls 13 (first flow passage protrusions) protruding upward (perpendicular to the bottom surface 12a) from a bottom surface 12a (described later) of the lower steam flow passage recess 12 of the lower metal sheet 10 are provided. In this case, the lower flow passage walls 13 protrude in a direction perpendicular to the bottom surface 12a, but the present invention is not limited to this and may protrude in a direction not perpendicular to the bottom surface 12a. In this embodiment, an example is shown in which the lower flow passage walls 13 extend in an elongated shape along the first direction X (longitudinal direction, left-right direction in FIG. 4) of the vapor chamber 1. The lower flow passage walls 13 include an upper surface 13a (abutment surface, protruding end surface) that abuts against a lower surface 22a of the upper flow passage wall 22 described later. The upper surface 13a is a surface that is not etched by an etching process described later, and is formed on the same plane as the upper surface 10a of the lower metal sheet 10. The lower flow passage walls 13 are disposed parallel to each other and spaced apart at equal intervals.

[0035] As shown in FIG. 3 and FIG. 4, the lower steam passage recess 12 includes a plurality of lower steam passages 81 (first steam passages) partitioned by the lower passage wall 13. The lower steam passages 81 extend in an elongated shape along the first direction X and are arranged in parallel to each other. Both ends of each lower steam passage 81 communicate with a lower communication steam passage 82 extending in an elongated shape along the second direction Y, and each lower steam passage 81 communicates with the lower communication steam passage 82. In this manner, the steam of the working fluid 2 flows around each lower passage wall 13 (the lower steam passage 81 and the lower communication steam passage 82) and is transported toward the periphery of the lower steam passage recess 12, suppressing the flow of the steam from being impeded. In FIG. 3, the cross-sectional shape (cross-section in the second direction Y) of the lower steam passage 81 of the lower steam passage recess 12 is rectangular. However, the present invention is not limited to this, and the cross-sectional shape of the lower steam passage 81 may be, for example, curved, semicircular, or V-shaped, and is arbitrary as long as it can diffuse the vapor of the working fluid 2. The same applies to the lower communication steam passage 82. A width (dimension in the second direction Y) w7 of the lower steam passage 81 corresponds to the distance between the lower flow path wall portions 13 described later. The width (dimension in the first direction X) of the lower communication steam passage 82 is also similar.

[0036] The lower flow passage wall 13 is disposed so as to overlap the corresponding upper flow passage wall 22 (described later) of the upper metal sheet 20 in a plan view, thereby improving the mechanical strength of the vapor chamber 1. The lower steam passage 81 is formed so as to overlap the corresponding upper steam passage 83 (described later) in a plan view. Similarly, the lower communication steam passage 82 is formed so as to overlap the corresponding upper communication steam passage 84 (described later) in a plan view.

[0037] The width w0 of the lower flow passage wall 13 is, for example, 0.05 mm to 30 mm, preferably 0.05 mm to 2.0 mm, and the width w7 of the lower steam passage 81 of the lower steam flow passage recess 12 (i.e., the interval between the adjacent lower flow passage walls 13) is 0.05 mm to 30 mm, preferably 0.05 mm to 2.0 mm. Here, the widths w0 and w7 are the dimensions of the lower flow passage wall 13 and the lower steam flow passage recess 12 in the second direction Y of the lower flow passage wall 13, respectively meaning the dimensions on the upper surface 10a of the lower metal sheet 10, and correspond to the dimensions in the up-down direction in FIG. 4, for example. In addition, the height h0 of the lower flow passage wall 13 (in other words, the maximum depth of the lower steam flow passage recess 12) (see FIG. 3) is preferably at least 10 μm or more smaller than the thickness T1 of the lower metal sheet 10. If the remainder obtained by subtracting h0 from T1 is 10 μm or more, the lower vapor flow path recess 12 can be prevented from being damaged due to insufficient strength. The thickness of the vapor chamber 1 may be 0.1 mm to 2.0 mm, and the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 may be equal. For example, when the thickness of the vapor chamber 1 is 0.5 mm and T1 and T2 are the same, h0 is preferably 200 μm.

[0038] 3 and 4, a lower peripheral wall 14 is provided on the peripheral portion of the lower metal sheet 10. The lower peripheral wall 14 is formed so as to surround the sealed space 3, particularly the lower steam flow path recess 12, and defines the sealed space 3. Furthermore, lower alignment holes 15 for positioning the lower metal sheet 10 and the upper metal sheet 20 are provided at the four corners of the lower peripheral wall 14 in a plan view.

[0039] The lower injection protrusion 16 of the injection part 4 described above is used when degassing the sealed space 3 and injecting the liquid working fluid 2 toward the sealed space 3 during the manufacture of the vapor chamber 1. The lower injection protrusion 16 is formed to protrude outward from the end face of the lower metal sheet 10 in a plan view. Note that the lower injection protrusion 16 is formed at a position shifted from the center of the width direction (second direction Y) of the lower metal sheet 10, but is not limited thereto, and may be formed at the center of the width direction (second direction Y) of the lower metal sheet 10.

[0040] A lower injection flow path recess 17 is formed on the upper surface of the lower injection protrusion 16, extending along the longitudinal direction (first direction X) of the lower metal sheet 10. The lower injection flow path recess 17 is formed as a non-through recess formed by half-etching from the upper surface side of the lower injection protrusion 16. An opening 17a is formed on the outer end (the end opposite to the lower steam flow path recess 12) of the lower injection flow path recess 17 for degassing the sealed space 3 and for injecting the liquid working fluid 2 into the sealed space 3. This opening 17a communicates between the lower injection flow path recess 17 and the outside of the vapor chamber 1, and is open toward the outside (the opposite side to the lower steam flow path recess 12).

[0041] Bank portions 51 are formed on both sides in the width direction (second direction Y) of the lower injection flow path recess 17. These bank portions 51 constitute wall portions on both sides of the lower injection flow path recess 17. The bank portions 51 are regions that are not etched, and their upper surfaces are formed on the same plane as the upper surface 10a of the lower metal sheet 10.

[0042] The length (distance in the first direction X) L1 of the lower injection protrusion 16 may be, for example, 5 mm to 30 mm, preferably 5 mm to 20 mm, and the width (distance in the second direction Y) w8 of the lower injection protrusion 16 may be, for example, 4 mm to 15 mm, preferably 4 mm to 10 mm. The width w9 of the lower injection flow path recess 17 is, for example, 1 mm to 10 mm, preferably 1 mm to 6 mm. The width w9 means the dimension of the lower injection flow path recess 17 in the second direction Y, and corresponds to the dimension in the up-down direction in FIG. 4, for example. By making L1 5 mm or more, the workability is improved when evacuating the sealed space 3, and by making it 30 mm or less, defects such as deformation are unlikely to occur during work such as evacuation. By making w8 4 mm or more, the width of the bank portion 51 sufficient for joining can be obtained while securing the width w9 of the lower injection flow path recess 17, and by making it 15 mm or less, work such as evacuation is facilitated. By making w9 1 mm or more, the cross-sectional area of ​​the injection flow path becomes wider, making it possible to efficiently and quickly perform the degassing operation and the injection operation of the working fluid 2, and by making it 10 mm or less, leakage after crimping is less likely to occur.

[0043] The width w9 of the lower injection flow path recess 17 may be wider than the width w7 of the lower steam passage 81 described above. In this case, for example, the width w7 is 0.05 mm to 2.0 mm, and the width w9 is 1 mm to 10 mm. Also, the width w9 of the lower injection flow path recess 17 is preferably 1.5 times or more the width w7 of the lower steam passage 81. More specifically, for example, when the width w7 is 0.05 mm, the width w9 may be 1 mm to 6 mm, and preferably 1 mm to 3 mm. Also, for example, when the width w7 is 2 mm, the width w9 may be 3.5 mm to 10 mm, and preferably 3.5 mm to 6 mm. In this way, by making the width w9 of the lower injection flow path recess 17 wider than the width w7 of the lower steam passage 81, degassing from the sealed space 3 and injection of the working fluid 2 into the sealed space 3 can be performed quickly.

[0044] The width w9 of the lower injection flow path recess 17 refers to the width of the lower injection flow path recess 17 at its widest portion, for example, the maximum distance between both bank portions 51. Similarly, the width w7 of the lower steam passage 81 refers to the width of the lower steam flow path recess 12 at its widest portion.

[0045] Next, the configuration of the lower injection flow path recess 17 will be further described with reference to Figures 6 and 7. As shown in Figure 6, the lower injection flow path recess 17 is formed with an inlet region 52, an intermediate region 53, and a crimped region 54 along the longitudinal direction from the opening 17a toward the sealed space 3.

[0046] Among these, the inlet region 52 is a region into which the liquid working fluid 2 is poured from the opening 17a, and is in direct communication with the opening 17a, and has a substantially flat bottom surface 17b without any irregularities.

[0047] The intermediate region 53 is located between the inlet region 52 and the crimped region 54. In this intermediate region 53, a plurality of support columns 55 are provided to protrude from the lower injection flow path recess 17. Each support column 55 protrudes upward from the bottom surface 17b. Each support column 55 is a non-etched region, and its upper surface is formed on the same plane as the upper surface 10a of the lower metal sheet 10. The lower surface 20a of the upper metal sheet 20 contacts the upper surface of each support 55 (see FIG. 7). The multiple support columns 55 improve the strength of the lower injection flow path recess 17 and prevent the lower injection protrusion 16 from deforming and blocking the inside of the lower injection flow path recess 17. By providing a plurality of supports 55 in this manner, an internal space of the lower injection flow path recess 17 is ensured, and degassing of the sealed space 3 and injection of the working fluid 2 into the sealed space 3 can be performed more reliably.

[0048] The support pillars 55 are formed in a plurality of columns (in the present embodiment, four columns in the first direction X and two columns in the second direction Y, a total of eight columns) along the longitudinal direction (first direction X) and width direction (second direction Y) of the lower injection flow path recess 17. Each support pillar 55 has a rectangular shape in plan view, but is not limited thereto, and may have a circular, elliptical, or polygonal shape in plan view. The shapes of the multiple support pillars 55 are the same as each other, but the shapes of the multiple support pillars 55 may be different from each other. The width w10 of each support pillar 55 may be, for example, 0.1 mm to 2 mm. Furthermore, the interval p1 between the support pillars 55 may be, for example, 0.1 mm to 2 mm, and the interval p2 between the support pillar 55 and the bank portion 51 may be, for example, 0.1 mm to 2 mm. By setting w10 to 0.1 mm or more, the strength of the support pillars is improved, and by setting it to 2 mm or less, the deaeration work and the injection work of the working fluid 2 can be efficiently and quickly performed. By making p1 and p2 0.1 mm or more, degassing operations and injection operations of the working fluid 2 can be performed efficiently and quickly, and by making them 2 mm or less, deformation of the upper injection protrusion 25 is less likely to occur during joining, and narrowing of the cross-sectional area of ​​the injection flow path can be suppressed.

[0049] The crimped region 54 is a region that is closed and sealed by crimping (pressing and plastically deforming) after the hydraulic fluid 2 is injected into the sealed space 3. The crimped region 54 has a plurality of protrusions 56 protruding upward in the lower injection flow path recess 17. Each protrusion 56 is a region that is not etched, and its upper surface is formed on the same plane as the upper surface 10a of the lower metal sheet 10. The upper surface of each protrusion 56 is in contact with the lower surface 20a of the upper metal sheet 20 (see FIG. 7). The plurality of protrusions 56 are crushed by crimping and deformed to close the lower injection flow path recess 17. By providing the plurality of protrusions 56 in the crimped region 54 in this way, the sealed space 3 into which the hydraulic fluid 2 is injected can be sealed more reliably.

[0050] The plurality of protrusions 56 are formed in the longitudinal direction (first direction X) and width direction (second direction Y) of the lower injection flow path recess 17. Each protrusion 56 has a rectangular shape in a plan view, but is not limited thereto, and may have a circular, elliptical, or polygonal shape in a plan view. The width w11 of each protrusion 56 may be, for example, 0.01 mm to 0.5 mm, and the interval p3 between the protrusions 56 may be, for example, 0.01 mm to 0.5 mm. The width w11 of each protrusion 56 is smaller than the width w10 of each support 55, and the interval p3 between the protrusions 56 is smaller than the interval p1 between the support 55. As described above, the width w9 of the lower injection flow path recess 17 is formed sufficiently wider than the width w7 of the lower steam passage 81, so that the presence of the plurality of protrusions 56 in the crimped region 54 can be prevented from impeding the degassing operation in the sealed space 3 or the injection operation of the working fluid 2 into the sealed space 3.

[0051] As shown in Fig. 7, the depth d1 of the lower injection flow path recess 17 may be, for example, 40 µm to 300 µm. In this case, the depth d1 of the lower injection flow path recess 17 may be deeper than the depth h0 of the lower vapor flow path recess 12. In this case, for example, the depth h0 is 10 µm to 200 µm, and the depth d1 is 40 µm to 300 µm. More specifically, for example, when the depth h0 is 0.1 mm, the width w7 may be 0.3 mm to 1.5 mm, and preferably 0.5 mm to 1.2 mm. Also, in this case, when the depth d1 is 0.15 mm, the width w9 may be 1.3 mm to 10 mm, and preferably 1.5 mm to 6 mm. In this way, by making the depth d1 of the lower injection flow path recess 17 deeper than the depth h0 of the lower steam flow path recess 12, it is possible to quickly degas from the sealed space 3 to the lower injection flow path recess 17 and quickly inject the working fluid 2 from the lower injection flow path recess 17 into the sealed space 3. The depth d1 of the lower injection flow path recess 17 refers to the depth of the deepest part of the lower injection flow path recess 17, and refers to the maximum distance (distance in the Z direction) between the upper surface 10a of the lower metal sheet 10 and the bottom surface 17b of the lower injection flow path recess 17. In this embodiment, the depth d1 of the lower injection flow path recess 17 corresponds to the depth of the lower injection flow path recess 17 in the inlet region 52 and the intermediate region 53. The depth h0 of the lower steam flow path recess 12 refers to the depth of the deepest part of the lower steam flow path recess 12.

[0052] As shown in FIG. 7, the depth d1 of the lower injection flow passage recess 17 is the same in the inlet region 52 and the intermediate region 53. However, the present invention is not limited to this, and the depth of the lower injection flow passage recess 17 in the inlet region 52 may be deeper than the depth of the lower injection flow passage recess 17 in the intermediate region 53. Furthermore, the depth d2 of the lower injection flow passage recess 17 in the crimping region 54 is shallower than the depth d1 of the lower injection flow passage recess 17 in the inlet region 52 and the intermediate region 53. This allows the multiple protrusions 56 to be easily crushed by crimping, and the sealed space 3 into which the working fluid 2 is injected can be sealed more reliably. Note that when the injection flow passage is blocked using a method other than crimping, such as brazing, such a crimping region 54 does not need to be provided.

[0053] Next, the configuration of the upper metal sheet 20 will be described. In this embodiment, the upper metal sheet 20 is different from the lower metal sheet 10 in that the liquid flow path section 30 described later is not provided and the configuration of the upper injection protrusion section 25 is different. The configuration of the upper metal sheet 20 will be described in more detail below.

[0054] As shown in FIG. 3 and FIG. 5, the upper metal sheet 20 has an upper steam flow path recess 21 (second steam flow path section) provided on the lower surface 20a. This upper steam flow path recess 21 constitutes a part of the sealed space 3, and is mainly configured to diffuse and cool the steam generated in the evaporation section 11. More specifically, the steam in the upper steam flow path recess 21 diffuses in a direction away from the evaporation section 11, and most of the steam is transported toward the peripheral portion having a relatively low temperature. Also, as shown in FIG. 3, a housing member Ha constituting a part of the housing of a mobile terminal or the like is disposed on the upper surface 20b of the upper metal sheet 20. As a result, the steam in the upper steam flow path recess 21 is cooled by the outside air via the upper metal sheet 20 and the housing member Ha.

[0055] In this embodiment, as shown in Figs. 2, 3 and 5, a plurality of upper flow passage walls 22 (second flow passage walls, second flow passage protrusions) protruding downward (perpendicular to the bottom surface 21a) from the bottom surface 21a of the upper steam flow passage recess 21 of the upper metal sheet 20 are provided. In this embodiment, an example is shown in which the upper flow passage walls 22 extend in an elongated shape along the first direction X (left-right direction in Fig. 5) of the vapor chamber 1. The upper flow passage walls 22 include a flat lower surface 22a (abutment surface, protruding end surface) that abuts against the upper surface 10a of the lower metal sheet 10 (more specifically, the upper surface 13a of the above-mentioned lower flow passage wall 13). Moreover, the upper flow passage walls 22 are arranged parallel to each other at equal intervals.

[0056] As shown in FIG. 3 and FIG. 5, the upper steam passage recess 21 includes a plurality of upper steam passages 83 (second steam passages) partitioned by the upper passage wall 22. The upper steam passages 83 extend in an elongated shape along the first direction X and are arranged in parallel to each other. Both ends of each upper steam passage 83 communicate with an upper communication steam passage 84 extending in an elongated shape along the second direction Y, and each upper steam passage 83 communicates with the upper communication steam passage 84. In this manner, the vapor of the working fluid 2 flows around each upper passage wall 22 (the upper steam passage 83 and the upper communication steam passage 84) and is transported toward the periphery of the upper steam passage recess 21, suppressing the flow of the vapor from being impeded. In FIG. 3, the cross-sectional shape (cross-section in the second direction Y) of the upper steam passage 83 of the upper steam passage recess 21 is rectangular. However, this is not limited thereto, and the cross-sectional shape of the upper steam passage 83 may be, for example, curved, semicircular, or V-shaped, and is arbitrary as long as it can diffuse the vapor of the working fluid 2. The cross-sectional shape of the upper communication steam passage 84 is similar. The width (dimension in the second direction Y) of the upper steam passage 83 and the width of the upper communication steam passage 84 may be similar to the width of the lower steam passage 81 and the width of the lower communication steam passage 82, as shown in Fig. 3 etc., but may be different.

[0057] The upper flow passage wall 22 is disposed so as to overlap the corresponding lower flow passage wall 13 of the lower metal sheet 10 in a plan view, thereby improving the mechanical strength of the vapor chamber 1. Moreover, the upper steam passage 83 is formed so as to overlap the corresponding lower steam passage 81 in a plan view. Similarly, the upper communication steam passage 84 is formed so as to overlap the corresponding lower communication steam passage 82 in a plan view.

[0058] It is preferable that the width and height of the upper flow path wall portion 22 are the same as the width w0 and height h0 of the above-mentioned lower flow path wall portion 13. Here, the bottom surface 21a of the upper steam flow path recess 21 can also be called a ceiling surface in terms of the vertical arrangement relationship between the lower metal sheet 10 and the upper metal sheet 20 as shown in Fig. 3, but since it corresponds to the back surface of the upper steam flow path recess 21, it will be referred to as the bottom surface 21a in this specification.

[0059] 3 and 5, an upper peripheral wall 23 is provided on the peripheral portion of the upper metal sheet 20. The upper peripheral wall 23 is formed so as to surround the sealed space 3, particularly the upper steam flow path recess 21, and defines the sealed space 3. Furthermore, upper alignment holes 24 for positioning the lower metal sheet 10 and the upper metal sheet 20 are provided at the four corners of the upper peripheral wall 23 in a plan view. That is, each upper alignment hole 24 is arranged so as to overlap with each lower alignment hole 15 described above when temporarily fastening as described later, and is configured so as to enable positioning of the lower metal sheet 10 and the upper metal sheet 20.

[0060] The upper injection protrusion 25 is configured to cover the lower injection flow path recess 17 of the lower injection protrusion 16 from above, thereby enabling the liquid working fluid 2 to be injected toward the sealed space 3. This upper injection protrusion 25 is formed to protrude outward from the end face of the upper metal sheet 20 in a plan view. Note that the upper injection protrusion 25 is formed at a position that overlaps with the lower injection protrusion 16 when the lower metal sheet 10 and the upper metal sheet 20 are joined together.

[0061] No injection flow path recess is formed on the lower surface of upper injection protrusion 25. Therefore, upper injection protrusion 25 is formed in a flat shape without any irregularities as a whole. In other words, upper injection protrusion 25 is a region that is not etched in its entirety by the etching process described below, and the lower surface of upper injection protrusion 25 is formed on the same plane as lower surface 20a of upper metal sheet 20.

[0062] However, without being limited thereto, an upper injection flow path recess (injection flow path recess) having a shape that is mirror symmetrical to the shape of lower injection flow path recess 17 may be formed on the lower surface of upper injection protrusion 25. Alternatively, an upper injection flow path recess (injection flow path recess) may be formed on the lower surface of upper injection protrusion 25, and lower injection flow path recess 17 may not be formed on lower injection protrusion 16.

[0063] The lower metal sheet 10 and the upper metal sheet 20 are permanently bonded to each other, preferably by diffusion bonding. More specifically, as shown in FIG. 3, the upper surface 14a of the lower peripheral wall 14 of the lower metal sheet 10 and the lower surface 23a of the upper peripheral wall 23 of the upper metal sheet 20 are in contact with each other, and the lower peripheral wall 14 and the upper peripheral wall 23 are bonded to each other. As a result, a sealed space 3 in which the working fluid 2 is sealed is formed between the lower metal sheet 10 and the upper metal sheet 20. In addition, the upper surface 13a of the lower flow path wall 13 of the lower metal sheet 10 and the lower surface 22a of the upper flow path wall 22 of the upper metal sheet 20 are in contact with each other, and each lower flow path wall 13 and the corresponding upper flow path wall 22 are bonded to each other. This improves the mechanical strength of the vapor chamber 1. In particular, since the lower flow path wall 13 and the upper flow path wall 22 according to this embodiment are disposed at equal intervals, it is possible to equalize the mechanical strength at each position of the vapor chamber 1. Note that the lower metal sheet 10 and the upper metal sheet 20 may be joined by other methods such as brazing, instead of diffusion bonding, as long as they can be permanently joined. It should be noted that the term "permanently bonded" is not limited to a strict meaning, but is used to mean that the upper surface 10a of the lower metal sheet 10 and the lower surface 20a of the upper metal sheet 20 are bonded to a degree that allows the sealing of the sealed space 3 to be maintained when the vapor chamber 1 is in operation.

[0064] Next, the configuration of the liquid flow path section 30 will be described in more detail with reference to Figures 8 and 9. Figure 8 is an enlarged plan view of the liquid flow path section 30, and Figure 9 is a cross-sectional view of the liquid flow path section 30.

[0065] As described above, the upper surface 10a of the lower metal sheet 10 (more specifically, the upper surface 13a of each lower flow path wall portion 13) is provided with a liquid flow path portion 30 through which the liquid working fluid 2 passes. The liquid flow path portion 30 constitutes a part of the sealed space 3 described above, and communicates with the lower steam flow path recess 12 and the upper steam flow path recess 21. Note that the liquid flow path portion 30 is not necessarily provided on all lower flow path walls 13. For example, there may be a lower flow path wall portion 13 on which no liquid flow path portion 30 is provided.

[0066] As shown in FIG. 8, the liquid flow path section 30 has a plurality of main flow grooves 31 extending parallel to each other, and communication grooves 32 that connect adjacent main flow grooves 31. The main flow grooves 31 extend along the main flow direction of the working fluid 2 (first direction X in this case). The communication grooves 32 extend along a direction perpendicular to the main flow direction of the working fluid 2 (second direction Y in this case), allowing the working fluid 2 to move between adjacent main flow grooves 31. The liquid working fluid 2 passes through the main flow grooves 31 and the communication grooves 32. The main flow grooves 31 and the communication grooves 32 mainly serve to transport the working fluid 2 condensed from the steam generated in the evaporation section 11 toward the evaporation section 11.

[0067] In addition, the liquid flow path section 30 has a plurality of protrusions 33 arranged in a staggered pattern in plan view. Each protrusion 33 is formed so as to be surrounded by a main flow groove 31 and a communication groove 32. In Fig. 8, the plurality of protrusions 33 have the same shape, and each protrusion 33 is formed in a rectangular shape so that the first direction X is the longitudinal direction in plan view. In this embodiment, the arrangement pitch of the protrusions 33 along the main flow direction of the working fluid 2 (in this case, the first direction X) is constant. That is, the multiple protrusions 33 are arranged at regular intervals in the first direction X, and are shifted in the first direction X by approximately half the length of the protrusion 33 relative to an adjacent protrusion 33 in the second direction Y.

[0068] It is preferable that the width w1 (dimension in the second direction Y) of the mainstream groove 31 is larger than the width w2 (dimension in the second direction Y) of the convex portion 33. In this case, the proportion of the mainstream groove 31 in the upper surface 13a of the lower flow path wall portion 13, the upper surface 14a of the lower peripheral wall 14, and the lower surface 23a of the upper peripheral wall 23 can be increased. This increases the cross-sectional area of ​​the mainstream groove 31 in the lower flow path wall portion 13, thereby improving the transport function of the liquid working fluid 2. For example, the width w1 of the mainstream groove 31 may be 20 μm to 200 μm, and the width w2 of the convex portion 33 may be 20 μm to 180 μm.

[0069] The depth h1 of the main flow groove 31 is preferably smaller than the height h0 (see FIG. 3) of the above-mentioned lower flow path wall portion 13. In this case, it is possible to enhance the capillary action of the main flow groove 31. For example, the depth h1 of the main flow groove 31 is preferably about half the height h0 of the lower flow path wall portion 13, and may be 5 μm to 200 μm.

[0070] Furthermore, it is preferable that the width w3 (dimension in the first direction X) of the communication grooves 32 is smaller than the width w1 of the main stream grooves 31. This makes it possible to suppress the working fluid 2 from flowing into the communication grooves 32 while the liquid working fluid 2 is being transported in each main stream groove 31 toward the evaporation section 11, thereby improving the transport function of the working fluid 2. On the other hand, when dryout occurs in any of the main stream grooves 31, the working fluid 2 can be moved from the adjacent main stream groove 31 via the corresponding communication groove 32, so that the dryout can be quickly eliminated and the transport function of the working fluid 2 can be ensured. In other words, as long as the communication grooves 32 can communicate with adjacent main grooves 31, they can fulfill their function even if they are smaller than the width of the main grooves 31. The width w3 of such communication grooves 32 may be, for example, 180 μm.

[0071] The depth (not shown) of the communication groove 32 may be shallower than the depth of the main groove 31 depending on the width w3. For example, the depth of the communication groove 32 may be 10 μm to 200 μm. The cross-sectional shape of the main groove 31 is not particularly limited, and may be, for example, rectangular, C-shaped, semicircular, semi-elliptical, curved, or V-shaped. The cross-sectional shape of the communication groove 32 is also similar.

[0072] As shown in Fig. 9, the liquid flow path portion 30 is formed on the upper surface 13a of the lower flow path wall portion 13 of the lower metal sheet 10. On the other hand, in this embodiment, the lower surface 22a of the upper flow path wall portion 22 of the upper metal sheet 20 is formed flat. As a result, each mainstream groove 31 of the liquid flow path portion 30 is covered by the flat lower surface 22a. In this case, as shown in Fig. 9, a pair of right-angled or acute-angled corners 37 can be formed by a pair of side walls 35, 36 of the mainstream groove 31 extending in the first direction X and the lower surface 22a of the upper flow path wall portion 22, and the capillary action at the corners 37 can be enhanced.

[0073] In this embodiment, the liquid flow path portion 30 is formed only in the lower metal sheet 10 . On the other hand, the steam flow path recesses 12, 21 are formed in both the lower metal sheet 10 and the upper metal sheet 20. However, this is not limited thereto, and it is sufficient that the liquid flow path portion 30 and the steam flow path recesses 12, 21 are formed in at least one of the lower metal sheet 10 and the upper metal sheet 20.

[0074] The shape of the liquid flow path portion 30 of the lower metal sheet 10 is not limited to that described above.

[0075] 10, the liquid flow path section 30 may have a plurality of main flow grooves 31 extending parallel to each other, and an elongated convex portion 33A formed between adjacent main flow grooves 31. In this case, each convex portion 33A extends along the main flow direction of the working fluid 2 (in this case, the first direction X) over substantially the entire longitudinal area of ​​the liquid flow path section 30. This allows each main flow groove 31 to efficiently transport the liquid working fluid 2 toward the evaporation section 11. Although not shown, a communication groove may be provided in a part of the convex portion 33A, and each main flow groove 31 may be connected to the lower steam flow path recess 12 or the upper steam flow path recess 21 through this communication groove.

[0076] The material used for the lower metal sheet 10 and the upper metal sheet 20 is not particularly limited as long as it has good thermal conductivity, but it is preferable to use, for example, copper (oxygen-free copper), copper alloy, aluminum, or stainless steel. In this case, the thermal conductivity of the lower metal sheet 10 and the upper metal sheet 20 can be increased, and the heat dissipation efficiency of the vapor chamber 1 can be improved. The thickness of the vapor chamber 1 may be 0.1 mm to 2.0 mm. FIG. 3 shows a case where the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 are equal, but this is not limited thereto, and the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 may not be equal.

[0077] Next, the operation of this embodiment having such a configuration will be described. First, the manufacturing method of the vapor chamber 1 will be described with reference to Figures 11(a)-(c) and 12(a)-(c), but the explanation of the half-etching process of the upper metal sheet 20 will be simplified. Note that Figures 11(a)-(c) and 12(a)-(c) show the same cross section as the cross section in Figure 3.

[0078] First, as shown in FIG. 11(a), in a preparation step, a flat metal material sheet M is prepared.

[0079] 11(b), a resist film 41 is formed by photolithography on each of an upper surface Ma and a lower surface Mb of the metal material sheet M. The resist film 41 formed on the upper surface Ma of the metal material sheet M has a pattern shape corresponding to the lower flow path wall portion 13 and the lower peripheral wall 14.

[0080] Next, as shown in FIG. 11(c), the metal material sheet M is half-etched to form the lower steam flow passage recess 12 that constitutes a part of the sealed space 3. As a result, the upper surface Ma of the metal material sheet M, which corresponds to the resist opening 41a of the resist film 41, is half-etched. Thereafter, the resist film 41 is removed from the metal material sheet M. As a result, as shown in FIG. 11(c), the lower steam flow passage recess 12, the lower flow passage wall 13, and the lower peripheral wall 14 are formed. At the same time, the liquid flow passage section 30 is formed in the lower flow passage wall 13 by half-etching. Note that, since the width of the resist opening 41a of the portion corresponding to the main flow passage groove 31 and the communication groove 32 of the liquid flow passage section 30 is narrow, the etching solution does not wrap around much. Therefore, the depth of the main flow passage groove 31 and the communication groove 32 is formed shallower than the depth of the lower steam flow passage recess 12. At this time, the lower injection flow passage recess 17 shown in FIG. 2 and FIG. 4 is also formed by etching at the same time, and the lower metal sheet 10 having a predetermined outer contour shape as shown in FIG. 4 is obtained.

[0081] Incidentally, half etching means etching for etching the material to be etched halfway in the thickness direction to form a recess that does not penetrate the material to be etched. Therefore, the depth of the recess formed by half etching is not limited to half the thickness of the material to be etched. The thickness of the material to be etched after half etching is, for example, 30% to 70%, preferably 40% to 60%, of the thickness of the material to be etched before half etching. The etching solution may be, for example, an iron chloride-based etching solution such as an aqueous ferric chloride solution, or a copper chloride-based etching solution such as an aqueous copper chloride solution.

[0082] Alternatively, the lower vapor flow path recess 12 may first be formed in the metal material sheet M by half etching (first half etching process), and then the liquid flow path portion 30 may be formed in the metal material sheet M in a separate etching process (second half etching process).

[0083] On the other hand, although not shown, in the same manner as the lower metal sheet 10, the upper metal sheet 20 is half-etched from the lower surface 20a to form the upper steam flow path recess 21, the upper flow path wall portion 22, and the upper peripheral wall 23. In this manner, the above-mentioned upper metal sheet 20 is obtained.

[0084] Next, as shown in FIG. 12(a), in a temporary fixing step, a lower metal sheet 10 having a lower steam flow passage recess 12 and an upper metal sheet 20 having an upper steam flow passage recess 21 are faced to each other and temporarily fixed.

[0085] In this case, first, the lower metal sheet 10 and the upper metal sheet 20 are positioned using the lower alignment hole 15 (see FIG. 2 and FIG. 4) of the lower metal sheet 10 and the upper alignment hole 24 (see FIG. 2 and FIG. 5) of the upper metal sheet 20. Then, the lower metal sheet 10 and the upper metal sheet 20 are fixed. The fixing method is not particularly limited, but for example, the lower metal sheet 10 and the upper metal sheet 20 may be fixed by resistance welding to the lower metal sheet 10 and the upper metal sheet 20. In this case, as shown in FIG. 12(a), it is preferable to perform resistance welding in spots using an electrode rod 40. Laser welding may be performed instead of resistance welding. Alternatively, the lower metal sheet 10 and the upper metal sheet 20 may be ultrasonically joined and fixed by irradiating ultrasonic waves. Furthermore, an adhesive may be used, but it is preferable to use an adhesive that does not contain an organic component or contains a small amount of organic components. In this manner, the lower metal sheet 10 and the upper metal sheet 20 are fixed in position.

[0086] After the temporary fixing, as shown in FIG. 12(b), the lower metal sheet 10 and the upper metal sheet 20 are permanently bonded by diffusion bonding as a permanent bonding process. Diffusion bonding is a method in which the lower metal sheet 10 and the upper metal sheet 20 to be bonded are brought into close contact with each other, and in a controlled atmosphere such as a vacuum or an inert gas, the metal sheets 10 and 20 are pressurized in a direction in which they are brought into close contact with each other and heated, thereby bonding them by utilizing the diffusion of atoms that occurs at the bonding surface. In diffusion bonding, the materials of the lower metal sheet 10 and the upper metal sheet 20 are heated to a temperature close to the melting point, but lower than the melting point, so that it is possible to prevent the metal sheets 10 and 20 from melting and deforming. More specifically, the upper surface 14a of the lower peripheral wall 14 of the lower metal sheet 10 and the lower surface 23a of the upper peripheral wall 23 of the upper metal sheet 20 are diffusion bonded as bonding surfaces. As a result, the lower peripheral wall 14 and the upper peripheral wall 23 form a sealed space 3 between the lower metal sheet 10 and the upper metal sheet 20. In addition, the lower injection flow path recess 17 (see Figs. 2 and 4) of the lower injection protrusion 16 and the upper injection protrusion 25 (see Figs. 2 and 5) form an injection flow path for the working fluid 2 communicating with the sealed space 3. Furthermore, the upper surface 13a of the lower flow path wall 13 of the lower metal sheet 10 and the lower surface 22a of the upper flow path wall 22 of the upper metal sheet 20 are diffusion bonded as a bonding surface, improving the mechanical strength of the vapor chamber 1. The liquid flow path portion 30 formed on the upper surface 13a of the lower flow path wall 13 remains as a flow path for the liquid working fluid 2.

[0087] After the permanent joining, as shown in FIG. 12(c), the working fluid 2 is injected into the sealed space 3 from the injection part 4 (see FIG. 2) as a sealing step. At this time, the sealed space 3 is first evacuated to reduce the pressure (for example, 5 Pa or less, preferably 1 Pa or less), and then the working fluid 2 is injected into the sealed space 3. During injection, the working fluid 2 passes through an injection flow path formed by the lower injection flow path recess 17 of the lower injection protrusion 16 and the upper injection protrusion 25. For example, the amount of the working fluid 2 to be sealed may be 10% to 40% of the total volume of the sealed space 3, depending on the configuration of the liquid flow path part 30 inside the vapor chamber 1. As described above, the width w9 of the lower injection flow path recess 17 constituting the injection flow path is wider than the width w7 of the lower steam passage 81 (see FIG. 4). Therefore, the operation of evacuating the injection flow path to reduce the pressure of the sealed space 3 and the operation of injecting the working fluid 2 from the injection flow path into the sealed space 3 can be efficiently performed in a short time.

[0088] Here, if the time for evacuating the sealed space 3 is shortened, there is a risk that non-condensable gas (e.g., air, etc.) in the sealed space 3 will not be extracted and will remain in the sealed space 3. Also, if the time for injecting the working fluid 2 is long, there is a risk that non-condensable gas will enter the sealed space 3 together with the working fluid 2. If non-condensable gas remains in the sealed space 3, it may hinder the movement of the vapor or liquid working fluid 2 of the working fluid 2 when the vapor chamber 1 is operated. In this case, it becomes difficult to obtain a desired heat transport efficiency. If the desired heat transport efficiency is not obtained by the heat transport test of the vapor chamber 1, the vapor chamber 1 is judged to be a defective product, and as a result, there is a possibility that the yield may decrease. The heat transport test is a test in which heat is applied to the vapor chamber 1 to measure the temperature of each part, and from the temperature measurement results, it is confirmed whether heat transport is normally performed in the vapor chamber 1 (for example, see JP 2004-301475 A).

[0089] In contrast to this, in this embodiment, as described above, the width w9 of the lower injection flow passage recess 17 constituting the injection flow passage is wider than the width w7 of the lower steam passage 81. Therefore, the operation of depressurizing the sealed space 3 by evacuating the injection flow passage and the operation of injecting the working fluid 2 from the injection flow passage into the sealed space 3 can be performed efficiently and in a short time. This makes it possible to prevent non-condensable gas from remaining in the sealed space 3 and to prevent a decrease in heat transport efficiency, thereby improving the yield.

[0090] After the working fluid 2 is injected, the above-mentioned injection flow path is sealed. In this case, for example, the crimping area 54 of the lower injection flow path recess 17 is crimped to crush and deform the multiple protrusions 56. This closes the injection part 4, seals the injection flow path, and completes the sealing of the sealed space 3. Alternatively, the injection part 4 may be irradiated with a laser to partially melt the injection part 4 and seal the injection flow path. Alternatively, the injection part 4 may be closed by brazing to seal the injection flow path. This blocks communication between the sealed space 3 and the outside air, and the working fluid 2 is enclosed in the sealed space 3. In this way, the working fluid 2 in the sealed space 3 is prevented from leaking to the outside. In order to more reliably seal the injection portion 4, laser irradiation or brazing may be performed after the crimping region 54 is crimped. In addition, after sealing the injection flow path, the injection portion 4 may be cut at any position on the opening 17a side of the crimping region 54 in the injection portion 4.

[0091] In this manner, the vapor chamber 1 according to the present embodiment is obtained.

[0092] In the present embodiment, an example in which the vapor chamber 1 is mainly manufactured by etching has been described. However, this is not limited to this, and the vapor chamber 1 may be manufactured by a 3D printer. For example, the vapor chamber 1 may be manufactured all at once by a 3D printer, or each metal sheet 10, 20 may be manufactured separately by a 3D printer and then joined.

[0093] Next, a method for operating the vapor chamber 1, that is, a method for cooling the device D, will be described.

[0094] The vapor chamber 1 obtained as described above is installed in a housing of a mobile terminal or the like, and a device D, such as a CPU, which is an object to be cooled, is attached to the lower surface 10b of the lower metal sheet 10. Since the amount of working fluid 2 injected into the sealed space 3 is small, the liquid working fluid 2 in the sealed space 3 adheres to the wall surfaces of the sealed space 3, i.e., the wall surfaces of the lower steam flow path recess 12, the upper steam flow path recess 21, and the liquid flow path section 30, due to its surface tension.

[0095] In this state, when the device D generates heat, the working liquid 2 present in the evaporation section 11 of the lower vapor passage recess 12 receives heat from the device D. The received heat is absorbed as latent heat, and the working liquid 2 evaporates (vaporizes), generating vapor of the working liquid 2. Most of the generated vapor diffuses in the lower vapor passage recess 12 and the upper vapor passage recess 21 that constitute the sealed space 3 (see the solid arrows in FIG. 4). The vapor in the upper vapor passage recess 21 and the lower vapor passage recess 12 leaves the evaporation section 11, and most of the vapor is transported toward the periphery of the vapor chamber 1, which has a relatively low temperature. The diffused vapor is cooled by dissipating heat to the lower metal sheet 10 and the upper metal sheet 20. The heat received by the lower metal sheet 10 and the upper metal sheet 20 from the vapor is transferred to the outside air via the housing member Ha (see FIG. 3).

[0096] The steam radiates heat to the lower metal sheet 10 and the upper metal sheet 20, thereby losing the latent heat absorbed in the evaporation section 11 and condensing. The condensed liquid working fluid 2 adheres to the wall surface of the lower vapor flow passage recess 12 or the wall surface of the upper vapor flow passage recess 21. Here, since the working fluid 2 continues to evaporate in the evaporation section 11, the working fluid 2 in the portion of the liquid flow passage section 30 other than the evaporation section 11 is transported toward the evaporation section 11 (see the dashed arrow in FIG. 4). As a result, the liquid working fluid 2 adhering to the wall surface of the lower vapor flow passage recess 12 and the wall surface of the upper vapor flow passage recess 21 moves toward the liquid flow passage section 30 and enters the liquid flow passage section 30. Therefore, the working fluid 2 filled in the liquid flow passage section 30 obtains a driving force toward the evaporation section 11 due to the capillary action of each main stream groove 31, and is smoothly transported toward the evaporation section 11.

[0097] The working liquid 2 that reaches the evaporation section 11 is evaporated again by receiving heat from the device D. In this way, the working liquid 2 circulates through the vapor chamber 1 while repeating phase changes, i.e., evaporation and condensation, and transfers and releases the heat of the device D. As a result, the device D is cooled.

[0098] Thus, according to this embodiment, the width w9 of the lower injection flow path recess 17 is wider than the width w7 of the lower steam passage 81. Therefore, the cross section of the lower injection flow path recess 17 in the width direction (second direction Y) is wider than the cross section of the lower steam passage 81 in the width direction (second direction Y). This makes it possible to efficiently and quickly perform the operation of evacuating the injection flow path to degas the sealed space 3 and the operation of injecting the working fluid 2 into the sealed space 3 when manufacturing the vapor chamber 1. In particular, when the width w9 of the lower injection flow path recess 17 is set to 1.5 times or more the width w7 of the lower steam passage 81, such an effect can be obtained significantly.

[0099] Furthermore, according to this embodiment, since a plurality of support columns 55 are provided protruding from the lower injection flow path recess 17, it is possible to suppress deformation of the lower injection flow path recess 17. This makes it possible to prevent the deformation of the lower injection flow path recess 17 from interfering with the degassing operation in the sealed space 3 and the injection operation of the working fluid 2 into the sealed space 3 during the manufacture of the vapor chamber 1, and therefore makes it possible to efficiently perform the degassing operation and the injection operation.

[0100] Furthermore, according to this embodiment, a crimped region 54 is formed in the lower injection flow path recess 17, and this crimped region 54 has a plurality of protrusions 56. These plurality of protrusions 56 are crushed when the crimped region 54 is crimped after the working fluid 2 is injected into the sealed space 3. This makes it possible to seal the sealed space 3 even more reliably.

[0101] Furthermore, according to this embodiment, the depth d1 of the lower injection flow path recess 17 is deeper than the depth h0 of the vapor flow path recess 12, and therefore the cross-sectional area of ​​the lower injection flow path recess 17 in the width direction (second direction Y) is larger than the cross-sectional area of ​​the lower vapor passage 81 in the width direction (second direction Y). This allows the degassing operation in the sealed space 3 and the injection operation of the working fluid 2 into the sealed space 3 to be performed efficiently during the manufacture of the vapor chamber 1.

[0102] Furthermore, according to this embodiment, the liquid flow path section 30 has a plurality of main grooves 31 extending parallel to one another, and communication grooves 32 connecting adjacent main grooves 31. This allows the liquid working fluid 2 to flow between adjacent main grooves 31, suppressing the occurrence of dryout in the main grooves 31. As a result, a capillary action is imparted to the working fluid 2 in each main groove 31, and the working fluid 2 is smoothly transported toward the evaporation section 11.

[0103] Furthermore, according to this embodiment, the liquid flow path section 30 has a plurality of protruding portions 33 arranged in a staggered manner in a plan view. This allows the capillary action acting on the working fluid 2 in the main stream groove 31 to be uniform in the width direction of the main stream groove 31. That is, since the plurality of protruding portions 33 are arranged in a staggered manner in a plan view, the communication grooves 32 are connected alternately to both sides of the main stream groove 31. Therefore, unlike a case in which the communication grooves 32 are connected to the same positions on both sides of each main stream groove 31, it is possible to suppress the loss of the capillary action in the direction toward the evaporation section 11 due to the communication grooves 32. Therefore, it is possible to suppress the reduction of the capillary action at the intersections of the main stream grooves 31 and the communication grooves 32, and it is possible to continuously impart the capillary action to the working fluid 2 heading toward the evaporation section 11.

[0104] In addition, since the inside of the sealed space 3 is decompressed as described above, the lower metal sheet 10 and the upper metal sheet 20 are subjected to pressure from the outside air in a direction in which they are recessed inward in the thickness direction. Here, if the communication grooves 32 are connected to the same positions on both sides of each main groove 31 in the longitudinal direction, it is considered that the lower metal sheet 10 and the upper metal sheet 20 will be recessed inward in the thickness direction along a direction parallel to the communication grooves 32. In this case, the flow path cross-sectional area of ​​each main groove 31 will be reduced, and the flow path resistance of the working fluid 2 may increase. In contrast, in this embodiment, the liquid flow path section 30 has a plurality of protrusions 33 arranged in a staggered manner in a plan view. As a result, even if the lower metal sheet 10 and the upper metal sheet 20 are recessed inward in the thickness direction along the communication grooves 32, the recess is prevented from crossing the main groove 31, the flow path cross-sectional area of ​​the main groove 31 can be secured, and the flow of the working fluid 2 is prevented from being hindered.

[0105] Next, modified examples of the vapor chamber will be described with reference to Figures 13 and 14. In Figures 13 and 14, the same parts as those in Figures 1 to 12 are given the same reference numerals and detailed description thereof will be omitted.

[0106] (Variation 1) Fig. 13 shows a vapor chamber 1A according to one modified example (modified example 1). In the vapor chamber 1A shown in Fig. 13, unlike the embodiment shown in Figs. 1 to 12, the upper steam flow passage recess 21 is not formed in the upper metal sheet 20. Although not shown in Fig. 13, the width of the injection flow passage recess (the lower injection flow passage recess 17 or the upper injection flow passage recess) is wider than the width of the lower steam passage 81. In this case, it is possible to reduce the thickness of the upper metal sheet 20, thereby reducing the thickness of the entire vapor chamber 1.

[0107] (Variation 2) FIG. 14 shows a vapor chamber 1B according to another modified example (modified example 2). In the vapor chamber 1B shown in FIG. 14, unlike the embodiment shown in FIG. 1 to FIG. 12, the lower metal sheet 10 does not have the lower vapor flow path recess 12, and the liquid flow path portion 30 is provided on the upper surface 10a of the lower metal sheet 10. The liquid flow path portion 30 is formed not only in the region of the upper surface 10a facing the upper flow path wall portion 22, but also in the region facing the upper vapor flow path recess 21. Although not shown in FIG. 14, the width of the injection flow path recess (the lower injection flow path recess 17 or the upper injection flow path recess) is wider than the width of the upper vapor flow path recess 21. In this case, the number of the main grooves 31 constituting the liquid flow path portion 30 can be increased, and the transport function of the liquid working fluid 2 can be improved. However, the region in which the liquid flow path portion 30 is formed is not limited to the region shown in FIG. 14, and may be any region as long as the transport function of the liquid working fluid 2 can be ensured. Moreover, it is possible to reduce the thickness of the lower metal sheet 10, thereby enabling the thickness of the entire vapor chamber 1 to be reduced.

[0108] (Variation 3) 15 is a diagram showing a vapor chamber 1C according to another modified example (modified example 3), and corresponds to FIG. 7 described above. In the vapor chamber 1C shown in FIG. 15, unlike the embodiment shown in FIGS. 1 to 12, the shape of each protrusion 56 in the crimped region 54 is substantially the same as the shape of each support 55 in the intermediate region 53. In addition, the depth of the lower injection flow path recess 17 in the crimped region 54 is the same as the depth d1 of the lower injection flow path recess 17 in the inlet region 52 and the intermediate region 53. In this case, the interval p3 between the protrusions 56 is widened, and the lower injection flow path recess 17 is deformed, so that the degassing operation in the sealed space 3 and the injection operation of the working fluid 2 into the sealed space 3 can be efficiently performed.

[0109] (Variation 4) 16 is a diagram showing a vapor chamber 1D according to another modified example (modified example 4) and corresponds to FIG. 7 described above. In the vapor chamber 1D shown in FIG. 16, unlike the embodiment shown in FIGS. 1 to 12, the depth d1 of the lower injection flow path recess 17 is substantially uniform throughout the inlet region 52, the intermediate region 53, and the crimped region 54, and is the same as the depth h0 of the vapor flow path recess 12. In this case, since the depth d1 of the lower injection flow path recess 17 and the depth h0 of the vapor flow path recess 12 are the same, the degassing operation in the sealed space 3 and the injection operation of the working fluid 2 into the sealed space 3 can be smoothly performed by the deformation of the lower injection flow path recess 17.

[0110] (Second embodiment) Next, a vapor chamber, an electronic device, and a metal sheet for a vapor chamber according to a second embodiment of the present invention will be described with reference to FIGS.

[0111] The second embodiment shown in Figures 17 to 19 is different mainly in that an intermediate metal sheet is interposed between a lower metal sheet and an upper metal sheet, a steam flow path recess is formed in one of the lower metal sheet and the upper metal sheet, a liquid flow path portion is formed in the other, and a communication portion that communicates the steam flow path recess and the liquid flow path portion is provided in the intermediate metal sheet, but the other configuration is substantially the same as the first embodiment shown in Figures 1 to 16. Note that in Figures 17 to 19, the same parts as those in the first embodiment shown in Figures 1 to 16 are denoted by the same reference numerals and detailed description will be omitted.

[0112] As shown in FIG. 17, in this embodiment, an intermediate metal sheet 70 (third metal sheet) is interposed between a lower metal sheet 10 (first metal sheet) and an upper metal sheet 20 (second metal sheet). That is, in the vapor chamber 1 according to this embodiment, the lower metal sheet 10, the intermediate metal sheet 70, and the upper metal sheet 20 are laminated in this order. The intermediate metal sheet 70 is provided on the lower metal sheet 10, and the upper metal sheet 20 is provided on the intermediate metal sheet 70. In FIG. 17, the working fluid 2 is omitted in order to clarify the drawing. The same applies to FIG. 20, FIG. 22, and FIG. 25 described later.

[0113] The intermediate metal sheet 70 includes a lower surface 70a (first surface) provided on the side of the lower metal sheet 10, and an upper surface 70b (second surface) provided on the opposite side to the lower surface 70a and on the side of the upper metal sheet 20. Of these, the lower surface 70a is superimposed on the upper surface 10a of the lower metal sheet 10, and the upper surface 70b is superimposed on the lower surface 20a of the upper metal sheet 20. The lower metal sheet 10 and the intermediate metal sheet 70 are joined by diffusion bonding, and the intermediate metal sheet 70 and the upper metal sheet 20 are joined by diffusion bonding. The intermediate metal sheet 70 can be formed of the same material as the lower metal sheet 10 and the upper metal sheet 20. The intermediate metal sheet 70 has a thickness of, for example, 10 μm to 300 μm.

[0114] The sealed space 3 is formed between the lower metal sheet 10 and the upper metal sheet 20, and a part of the sealed space 3 is also formed in the intermediate metal sheet 70. In this embodiment, the sealed space 3 has a steam flow path section 80 through which mainly the vapor of the working fluid 2 passes, and a liquid flow path section 30 through which mainly the liquid working fluid 2 passes. The steam flow path section 80 and the liquid flow path section 30 are in communication with each other so that the working fluid 2 can return. The steam flow path section 80 has a lower steam flow path recess 12 (first steam flow path section) and an upper steam flow path recess 21 (second steam flow path section).

[0115] The lower metal sheet 10 including the lower steam flow path recess 12 and the liquid flow path portion 30 can have the same configuration as the lower metal sheet 10 in the first embodiment shown in Figures 1 to 16. Therefore, a detailed description will be omitted here.

[0116] In this embodiment, the upper metal sheet 20 is not provided with a liquid flow path section 30. The upper metal sheet 20 also has an upper steam flow path recess 21 (second steam flow path section) provided on the lower surface 20a. A plurality of upper flow path protrusions 90 (second flow path protrusions) are provided in the upper steam flow path recess 21, protruding downward (in a direction perpendicular to the bottom surface 21a) from the bottom surface 21a of the upper steam flow path recess 21. The upper flow path protrusions 90 are portions that are not etched in the half etching step, and the material of the upper metal sheet 20 remains.

[0117] 17, the upper flow path protrusion 90 has a lower surface 90a located on the same plane as the lower surface 20a of the upper metal sheet 20. This lower surface 90a abuts against the upper surface 70b of the intermediate metal sheet 70. This improves the mechanical strength of the vapor chamber 1 when the sealed space 3 is decompressed.

[0118] As shown in Fig. 18, in this embodiment, the upper flow passage protruding portions 90 are arranged in a staggered manner in a plan view. This allows the vapor of the working fluid 2 to flow around the upper flow passage protruding portions 90, thereby preventing the flow of the vapor from being obstructed. In addition, the planar shape of the lower surface of the upper flow passage protruding portion 90 is circular, which also prevents the flow of the vapor of the working fluid 2 from being obstructed. Note that the planar shape of the upper flow passage protruding portion 90 is not limited to a circular shape as long as it can prevent the flow of the vapor of the working fluid 2 from being obstructed.

[0119] 19, the intermediate metal sheet 70 is provided with communication holes 71 (communication portions) that communicate between the upper steam flow path recess 21 and the liquid flow path portion 30. The communication holes 71 penetrate the intermediate metal sheet 70 and form part of the above-mentioned sealed space 3. The communication holes 71 are disposed between the adjacent upper flow path protrusions 90 in a plan view, and the communication holes 71 are disposed in a staggered manner in a plan view.

[0120] 17, the communication holes 71 extend from the upper surface 70b to the lower surface 70a of the intermediate metal sheet 70. As a result, the liquid working fluid 2 generated by condensation of the vapor of the working fluid 2 in the upper vapor flow path recess 21 passes through the communication holes 71 and enters the mainstream grooves 31 of the liquid flow path section 30. On the other hand, the vapor of the working fluid 2 evaporated in the evaporation section 11 is not only diffused in the lower vapor flow path recess 12, but can also diffuse through the communication holes 71 into the upper vapor flow path recess 21.

[0121] The communication hole 71 may be formed by etching from the upper surface 70b of the intermediate metal sheet 70. In this case, the communication hole 71 may be curved in a shape that bulges toward the lower surface 70a. Alternatively, the communication hole 71 may be etched from the lower surface 70a of the intermediate metal sheet 70, and in this case, the communication hole 71 may be curved in a shape that bulges toward the upper surface 70b. Furthermore, the communication hole 71 may be formed by half etching from the lower surface 70a and half etching from the upper surface 70b. In this case, the shape or size of the communication hole 71 may be different between the part on the upper surface 70b side and the part on the lower surface 70a side. In this embodiment, as shown in FIG. 19, an example is shown in which the planar shape of the communication hole 71 is a circle. When the diameter φ of the communication hole 71 is the minimum diameter in the range from the upper surface 70b to the lower surface 70a, the diameter φ of the communication hole 71 may be, for example, 50 μm to 2000 μm. The planar shape of the communication hole 71 is not limited to a circular shape.

[0122] 19, in this embodiment, the communication hole 71 overlaps with a part of one lower steam passage 81 and a part of the other lower steam passage 81 of a pair of adjacent lower steam passages 81 in a plan view. This allows the pair of adjacent lower steam passages 81 to communicate with each other via the communication hole 71. This makes it possible to increase the flow path cross-sectional area of ​​the communication hole 71, and allows the steam of the working fluid 2 to be smoothly diffused to the upper steam flow path recess 21. Note that the communication hole 71 may overlap with a part of each of three or more lower steam passages 81 to communicate with these lower steam passages 81.

[0123] 19, the intermediate metal sheet 70 is provided with intermediate alignment holes 72 for positioning the metal sheets 10, 20, 70. That is, the intermediate alignment holes 72 are arranged to overlap the lower alignment holes 15 and the upper alignment holes 24 described above, respectively, when temporarily fastened, making it possible to position the metal sheets 10, 20, 70.

[0124] In this embodiment, the injection portion 4 may be formed in the same manner as the injection portion 4 in the first embodiment shown in Figures 1 to 16. That is, the lower metal sheet 10 has a lower injection protrusion 16, and a lower injection flow path recess (injection flow path recess) 17 is formed on the upper surface of the lower injection protrusion 16. The upper metal sheet 20 has an upper injection protrusion 25, but the lower surface of the upper injection protrusion 25 is formed in a flat shape without a recess being formed thereon.

[0125] The intermediate metal sheet 70 has an intermediate injection protrusion 75 protruding laterally from the end surface. However, the upper and lower surfaces of this intermediate injection protrusion 75 have no recesses and have the same thickness as the intermediate metal sheet 70 before processing. The upper and lower surfaces of the intermediate injection protrusion 75 are formed in a flat shape. When the lower metal sheet 10 and the intermediate metal sheet 70 are joined, the lower injection flow path recess 17 and the intermediate injection protrusion 75 form an injection flow path for the working fluid 2 together. When the lower metal sheet 10, the upper metal sheet 20 and the intermediate metal sheet 70 are joined, the injection protrusions 16, 25, 75 overlap each other. The intermediate injection protrusion 75 can be formed in the same manner as the upper injection protrusion 25.

[0126] However, the present invention is not limited to this. For example, in addition to or instead of the lower injection flow path recess 17, an injection flow path recess (injection flow path recess) may be formed on the lower surface of the upper injection protrusion 25. Alternatively, instead of such an injection portion 4, an injection hole may be provided in the lower metal sheet 10 or the upper metal sheet 20, and the working fluid 2 may be injected through this injection hole.

[0127] In the vapor chamber 1 according to this embodiment, the lower steam flow passage recess 12 and the liquid flow passage section 30 of the lower metal sheet 10 and the upper steam flow passage recess 21 of the upper metal sheet 20 can be formed in the same manner as in the first embodiment shown in Figs. 1 to 16. The communication hole 71 of the intermediate metal sheet 70 can also be formed by etching. Thereafter, the lower metal sheet 10 and the upper metal sheet 20 are joined via the intermediate metal sheet 70. That is, the lower metal sheet 10 and the intermediate metal sheet 70 are diffusion-bonded, and the upper metal sheet 20 and the intermediate metal sheet 70 are diffusion-bonded. This forms the sealed space 3. The lower metal sheet 10, the intermediate metal sheet 70, and the upper metal sheet 20 may be diffusion-bonded at the same time.

[0128] Thus, according to this embodiment, the intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20, the upper steam flow path recess 21 is provided on the lower surface 20a of the upper metal sheet 20, and the liquid flow path section 30 is provided on the upper surface 10a of the lower metal sheet 10. The intermediate metal sheet 70 is provided with a communication hole 71 that communicates the upper steam flow path recess 21 and the liquid flow path section 30. As a result, even when the vapor chamber 1 is formed of three metal sheets 10, 20, and 70, the working liquid 2 can be circulated in the vapor chamber 1 while repeatedly undergoing phase changes in the sealed space 3, and the heat of the device D can be transferred and released. In addition, since the upper steam flow path recess 21 of the upper metal sheet 20 is widely communicated, the vapor of the working liquid 2 can be smoothly diffused, and the heat transport efficiency can be improved.

[0129] 1 to 16, in this embodiment, the width w9 of the lower injection flow path recess 17 is wider than the width w7 of the lower vapor passage 81. This allows the operation of evacuating the injection flow path to degas the sealed space 3 and the operation of injecting the working fluid 2 into the sealed space 3 during the manufacture of the vapor chamber 1 to be performed efficiently and quickly.

[0130] 17 shows an example in which the cross-sectional shapes of the lower steam flow passage recess 12 and the upper steam flow passage recess 21 are formed into a rectangular shape. However, this is not limited thereto, and the cross-sectional shapes of the steam flow passage recesses 12, 21 may be formed into a curved shape. The same applies to the main groove 31 and the communication groove 32 of the liquid flow passage section 30.

[0131] In the above-described embodiment, an example has been described in which one intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20. However, this is not limited to this, and two or more intermediate metal sheets 70 may be interposed between the lower metal sheet 10 and the upper metal sheet 20.

[0132] (Third embodiment) Next, a vapor chamber, an electronic device, and a metal sheet for a vapor chamber according to a third embodiment of the present invention will be described with reference to Figs.

[0133] The third embodiment shown in Figures 20 and 21 is different in that the upper flow path protrusion and the communication hole extend in an elongated shape along the first direction, and other configurations are substantially the same as those of the second embodiment shown in Figures 17 to 19. In Figures 20 and 21, the same parts as those of the second embodiment shown in Figures 17 to 19 are denoted by the same reference numerals and detailed description thereof will be omitted.

[0134] As shown in Fig. 20, in this embodiment, an upper flow path protrusion 90 (second flow path protrusion) provided on an upper metal sheet 20 is configured similarly to the upper flow path wall 22 in the first embodiment shown in Fig. 1 to Fig. 16. For this reason, hereinafter, the upper flow path protrusion 90 will be referred to as the upper flow path wall 22, and a detailed description of the upper metal sheet 20 including the upper flow path protrusion 90 will be omitted.

[0135] As shown in Fig. 21, in this embodiment, the communication holes 71 provided in the intermediate metal sheet 70 are formed so as to extend in an elongated shape along the first direction X. In this embodiment as well, the communication holes 71 are disposed between the adjacent upper flow path wall portions 22 in a plan view. The width w4 of the communication holes 71 (the dimension in the second direction Y) may be, for example, 50 µm to 1500 µm. Here, the width w4 of the communication holes 71 is the minimum width in the range from the upper surface 70b to the lower surface 70a.

[0136] In the present embodiment, the communication hole 71 overlaps with one of the lower steam passages 81 of the lower steam passage recess 12 in a plan view. The communication hole 71 also overlaps with the upper steam passage 83 of the upper steam passage recess 21 which overlaps with the lower steam passage 81 in a plan view. That is, the communication hole 71 is provided between the lower steam passage 81 and the upper steam passage 83 which overlap with each other so as to overlap them. For this reason, the steam of the working fluid 2 in the lower steam passage 81 can quickly reach the upper steam passage 83 via the communication hole 71 and can be smoothly diffused into the upper steam passage 83.

[0137] Thus, according to this embodiment, the intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20, the upper steam flow path recess 21 is provided on the lower surface 20a of the upper metal sheet 20, and the liquid flow path section 30 is provided on the upper surface 10a of the lower metal sheet 10. The intermediate metal sheet 70 is provided with a communication hole 71 that communicates the upper steam flow path recess 21 with the liquid flow path section 30. As a result, even when the vapor chamber 1 is formed of three metal sheets 10, 20, and 70, the working liquid 2 can be circulated inside the vapor chamber 1 while repeatedly undergoing phase changes in the sealed space 3, and the heat of the device D can be transferred and released.

[0138] 1 to 16, in this embodiment, the width w9 of the lower injection flow path recess 17 is wider than the width w7 of the lower vapor passage 81. This allows the operation of evacuating the injection flow path to degas the sealed space 3 and the operation of injecting the working fluid 2 into the sealed space 3 during the manufacture of the vapor chamber 1 to be performed efficiently and quickly.

[0139] (Fourth embodiment) Next, a vapor chamber, an electronic device, and a metal sheet for a vapor chamber according to a fourth embodiment of the present invention will be described with reference to Figs.

[0140] In the fourth embodiment shown in Figures 22 to 25, an intermediate metal sheet is interposed between a lower metal sheet and an upper metal sheet, a steam flow path portion including a plurality of steam paths is formed on at least one of the lower and upper surfaces of the intermediate metal sheet, a liquid flow path portion is formed on at least one of the lower and upper surfaces of the intermediate metal sheet, an injected liquid flow path portion is formed on at least one of the lower and upper surfaces of the intermediate metal sheet, and the width of the injected flow path portion is wider than the width of the steam path, and the other configurations are substantially the same as those of the second embodiment shown in Figures 17 to 19. In Figures 22 to 25, the same parts as those of the second embodiment shown in Figures 17 to 19 are denoted by the same reference numerals and detailed description will be omitted.

[0141] As shown in Fig. 22, in this embodiment, the steam flow path section 80 is provided on the upper surface 70b of the intermediate metal sheet 70. That is, the steam flow path section 80 according to this embodiment is formed so as to extend from the upper surface 70b to the lower surface 70a of the intermediate metal sheet 70, penetrating the intermediate metal sheet 70. The liquid flow path section 30 is provided on the lower surface 70a of the intermediate metal sheet 70. For this reason, the intermediate metal sheet 70 according to this embodiment is sometimes referred to as a wick sheet. The steam flow path section 80 and the liquid flow path section 30 are in communication so that the working fluid 2 can return.

[0142] As shown in FIG. 23 and FIG. 24, the intermediate metal sheet 70 has a frame body portion 73 formed in a rectangular frame shape in a plan view, and a plurality of land portions 74 provided in the frame body portion 73. The frame body portion 73 and the land portion 74 are portions where the material of the intermediate metal sheet 70 remains without being etched when the intermediate metal sheet 70 is etched. The land portions 74 extend in an elongated shape along the first direction X, and a plurality of land portions 74 are arranged in the steam flow passage portion 80. The land portions 74 are supported by each other and by the frame body portion 73 via a support portion not shown. The support portion is formed so as to suppress the flow of the steam of the working fluid 2 flowing in the intermediate steam passage 85 described later from being obstructed. For example, the support portion may be formed in a part of the range from the upper surface 70b to the lower surface 70a of the intermediate metal sheet 70 in the vertical direction of FIG. 22.

[0143] The steam flow passage section 80 includes a plurality of intermediate steam passages 85 (third steam passages, steam passages) partitioned by the land sections 74. The intermediate steam passages 85 extend in an elongated shape along the first direction X and are arranged in parallel to each other. Both ends of each intermediate steam passage 85 communicate with an intermediate communication steam passage 86 extending in an elongated shape along the second direction Y, and each intermediate steam passage 85 communicates with the intermediate communication steam passage 86. In this manner, the steam of the working fluid 2 flows around each land section 74 (the intermediate steam passage 85 and the intermediate communication steam passage 86) and is transported toward the peripheral portion of the steam flow passage section 80, suppressing the flow of the steam from being impeded. In FIG. 22, the cross-sectional shape (cross-section in the second direction Y) of the intermediate steam passage 85 is rectangular. However, this is not limited to this, and the cross-sectional shape of the intermediate steam passage 85 may be, for example, curved, semicircular, or V-shaped, and may be any shape as long as it can diffuse the steam of the working fluid 2. The same applies to the intermediate communication steam passage 86. The intermediate communication steam passage 85 and the intermediate communication steam passage 86 can be formed by etching in the same manner as the communication hole 71 in the second embodiment shown in Figures 17 to 19, and can have the same cross-sectional shape as the communication hole 71.

[0144] The width w5 (dimension in the second direction Y) of the land portion 74 of the intermediate metal sheet 70 may be, for example, 50 μm to 2000 μm when taken as the maximum dimension in the range from the upper surface 70b to the lower surface 70a. The width w6 (dimension in the second direction Y) of the intermediate steam passage 85 may be, for example, 50 μm to 2000 μm when taken as the minimum dimension in the range from the upper surface 70b to the lower surface 70a. The same is true for the width (dimension in the first direction X) of the intermediate communication steam passage 86.

[0145] The liquid flow path portion 30 is provided in the land portion 74 on the lower surface 70a of the intermediate metal sheet 70. That is, the liquid flow path portion 30 is provided on the lower surface of the land portion 74.

[0146] In the present embodiment, the upper surface 10a of the lower metal sheet 10 does not have a lower steam flow path recess 12, and also does not have a liquid flow path section 30. The upper surface 10a is formed flat. Similarly, the lower surface 20a of the upper metal sheet 20 does not have an upper steam flow path recess 21, and also does not have a liquid flow path section 30. The lower surface 20a is formed flat. The thickness of the lower metal sheet 10 and the upper metal sheet 20 according to the present embodiment is, for example, 8 μm to 100 μm.

[0147] Furthermore, in the vapor chamber 1 according to this embodiment, the vapor flow path portion 80 and the liquid flow path portion 30 of the intermediate metal sheet 70 can be formed by etching. Thereafter, the lower metal sheet 10 and the upper metal sheet 20 are joined via the intermediate metal sheet 70. That is, the lower metal sheet 10 and the intermediate metal sheet 70 are diffusion bonded, and the upper metal sheet 20 and the intermediate metal sheet 70 are diffusion bonded. As a result, the sealed space 3 is formed. The lower metal sheet 10, the intermediate metal sheet 70 and the upper metal sheet 20 may be diffusion bonded at the same time.

[0148] In this embodiment, an intermediate injection flow path section 76 (injection flow path section) is formed in a concave shape on the lower surface of the intermediate injection protrusion 75 constituting the injection section 4. The lower injection flow path recess 17 is not formed on the upper surface of the lower injection protrusion 16, and the upper surface is formed in a flat shape. The lower injection protrusion 16 and the intermediate injection flow path section 76 form an injection flow path for the working fluid 2 together when the lower metal sheet 10 and the intermediate metal sheet 70 are joined. As shown in FIG. 24, no injection flow path section is formed on the upper surface of the intermediate injection protrusion 75, but the intermediate injection flow path section 76 may be formed on the upper surface of the intermediate injection protrusion 75 in addition to or instead of the lower surface of the intermediate injection protrusion 75.

[0149] The intermediate injection protrusion 75 and the intermediate injection channel portion 76 can be formed in the same manner as the lower injection protrusion 16 and the lower injection channel recess 17 in the first embodiment. For example, the intermediate injection protrusion 75 may have the same width w8 and length L1 as the lower injection protrusion 16. Also, for example, the intermediate injection channel portion 76 may have the same width w9 as the lower injection channel recess 17.

[0150] In this embodiment, the width w9 of the intermediate injection flow passage section 76 may be wider than the width w6 of the intermediate steam passage 85 described above. In this case, for example, the width w6 is 0.05 mm to 2.0 mm, and the width w9 is 1 mm to 10 mm. Also, it is preferable that the width w9 of the intermediate injection flow passage section 76 is 1.5 times or more the width w6 of the intermediate steam passage 85. More specifically, for example, when the width w6 is 0.05 mm, the width w9 may be 1 mm to 6 mm, and preferably 1 mm to 3 mm. Also, for example, when the width w6 is 2 mm, the width w9 may be 3.5 mm to 10 mm, and preferably 1 mm to 6 mm. In this way, by making the width w9 of the intermediate injection flow passage section 76 wider than the width w6 of the intermediate steam passage 85, degassing from the sealed space 3 and injection of the working fluid 2 into the sealed space 3 can be performed quickly.

[0151] The intermediate injection flow passage portion 76 is not limited to being formed in a concave shape. For example, the intermediate injection flow passage portion 76 may be formed so as to extend from the lower surface 70a to the upper surface 70b of the intermediate metal sheet 70 and penetrate the intermediate metal sheet 70. In this case, the support pillar 55 may be supported by the bank portion 51 via a support portion not shown. The protrusion 56 may be formed in a columnar shape and supported by the bank portion 51 via a support portion not shown.

[0152] Thus, according to this embodiment, the intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20, a vapor flow path portion 80 is provided on the upper surface 70b of the intermediate metal sheet 70, and a liquid flow path portion 30 is provided on the lower surface 70a of the intermediate metal sheet 70. As a result, even when the vapor chamber 1 is formed of three metal sheets 10, 20, 70, the working liquid 2 can be circulated within the vapor chamber 1 while repeatedly undergoing phase changes within the sealed space 3, thereby transferring and releasing heat from the device D.

[0153] According to the present embodiment, the vapor flow path portion 80 is provided on the upper surface 70b of the intermediate metal sheet 70 interposed between the lower metal sheet 10 and the upper metal sheet 20, and the liquid flow path portion 30 is provided on the lower surface 70a. This makes it possible to eliminate the need for etching the lower metal sheet 10 and the upper metal sheet 20 to form the vapor flow path and the liquid flow path. In other words, the number of members to be etched can be reduced. This simplifies the manufacturing process of the vapor chamber 1, and the vapor chamber 1 can be easily manufactured. Furthermore, since the vapor flow path portion 80 and the liquid flow path portion 30 are formed in the intermediate metal sheet 70, the vapor flow path portion 80 and the liquid flow path portion 30 can be accurately positioned during the etching process. Therefore, in the assembly process, it is not necessary to align the vapor flow path section 80 and the liquid flow path section 30. As a result, the vapor chamber 1 can be easily manufactured. In addition, the height (or depth) of the vapor flow path can be determined by the thickness of the intermediate metal sheet 70, so that the vapor chamber 1 can be easily manufactured.

[0154] 1 to 16, the width w9 of the intermediate injection flow passage portion 76 is wider than the width w6 of the intermediate vapor passage 85. This allows the operation of evacuating the injection flow passage to degas the sealed space 3 and the operation of injecting the working fluid 2 into the sealed space 3 during the manufacture of the vapor chamber 1 to be performed efficiently and quickly.

[0155] Furthermore, according to this embodiment, the vapor flow path section 80 extends from the upper surface 70b to the lower surface 70a of the intermediate metal sheet 70. This can reduce the flow path resistance of the vapor flow path section 80. Therefore, the liquid working fluid 2 generated by condensation of the vapor of the working fluid 2 in the vapor flow path section 80 can smoothly enter the mainstream grooves 31 of the liquid flow path section 30. Meanwhile, the vapor of the working fluid 2 evaporated in the evaporation section 11 can be smoothly diffused in the vapor flow path section 80.

[0156] In the above-described embodiment, an example has been described in which the liquid flow path section 30 is provided on the lower surface 70a of the intermediate metal sheet 70. However, the present invention is not limited to this, and as shown in FIG. 25, the liquid flow path section 30 may be provided not only on the lower surface 70a but also on the upper surface 70b. In this case, it is possible to increase the number of flow paths for transporting the liquid working fluid 2 to the evaporation section 11 or a portion of the intermediate metal sheet 70 close to the evaporation section 11, thereby improving the transport efficiency of the liquid working fluid 2. As a result, it is possible to improve the heat transport efficiency of the vapor chamber 1.

[0157] In the above-described embodiment, an example has been described in which the steam flow path section 80 is formed to extend from the upper surface 70b to the lower surface 70a of the intermediate metal sheet 70. However, this is not limited to the above, and the steam flow path section 80 may be formed in a concave shape on the upper surface 70b of the intermediate metal sheet 70, like the lower steam flow path recess 12 shown in Figures 1 to 16, or like the upper steam flow path recess 21 shown in Figures 17 and 18. In this case, the intermediate metal sheet 70 may be provided with a communication hole (not shown) that communicates the steam flow path section 80 with the liquid flow path section 30.

[0158] In the above-described embodiment, an example has been described in which one intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20. However, this is not limited to this, and another metal sheet (not shown) may be interposed between the lower metal sheet 10 and the intermediate metal sheet 70, and another metal sheet (not shown) may be interposed between the upper metal sheet 20 and the intermediate metal sheet 70.

[0159] The present invention is not limited to the above-mentioned embodiments and modifications, and can be embodied by modifying the components without departing from the gist of the invention in the implementation stage. Various inventions can be formed by appropriately combining the components disclosed in the above-mentioned embodiments and modifications. Some components may be deleted from all the components shown in the embodiments and modifications. In the above-mentioned embodiments and modifications, the configuration of the lower metal sheet 10 and the configuration of the upper metal sheet 20 may be interchanged. [Explanation of symbols]

[0160] 1 Vapor chamber 2. Hydraulic Fluid 10 Lower metal sheet 12 Lower steam passage recess 17 Lower injection channel recess 20 Upper metal sheet 21 Upper steam passage recess 30 Liquid flow path section 31 Mainstream groove 32 Connecting groove 33 Convex 54 Crimping area 55 Post 56 Protrusion 70 Intermediate metal sheet 70a Bottom 70b top surface 71 Communication hole 76 Intermediate injection flow passage section 80 Steam flow passage 81 Lower steam passage 85 Middle steam passage 90 Upper channel protrusion D Device E-electronic equipment H Housing P intersection Q Buffer Space X 1st direction Y Second direction

Claims

1. A metal sheet for a vapor chamber for a vapor chamber having a sealed space in which a working fluid is sealed, The first page and a second surface provided on the opposite side to the first surface; Equipped with A vapor flow passage portion through which vapor of the working fluid passes is formed on the first surface, an injection flow path recess for injecting the hydraulic fluid in a liquid state is formed in the first surface; the injection flow path recess has one end communicating with the vapor flow path portion and another end provided on the opposite side to the one end, a first region of the injection channel recess located on the one end side is formed with a plurality of protrusions; a plurality of support columns are formed in a second region of the injection channel recess that is located closer to the other end than the first region; The distance between adjacent projections is narrower than the distance between adjacent posts. Metal sheet for vapor chamber.

2. the plurality of protrusions and the plurality of supports are formed along a width direction of the injection channel recess, The spacing between the projections and the spacing between the columns are spacings in the width direction. The metal sheet for a vapor chamber according to claim 1.

3. The plurality of protrusions and the plurality of supports are formed along the longitudinal direction and the width direction of the injection flow path recess, respectively. The metal sheet for a vapor chamber according to claim 2.

4. A metal sheet for a vapor chamber for a vapor chamber having a sealed space in which a working fluid is sealed, The first page and a second surface provided on the opposite side to the first surface; Equipped with A vapor flow passage portion through which vapor of the working fluid passes is formed on the first surface, an injection flow path recess for injecting the hydraulic fluid in a liquid state is formed in the first surface; the injection flow path recess has one end communicating with the vapor flow path portion and another end provided on the opposite side to the one end, a protrusion is formed in a first region located on the one end side of the injection flow path recess, a support is formed in a second region of the injection channel recess that is located closer to the other end than the first region; The width of the protrusion is smaller than the width of the support. Metal sheet for vapor chamber.

5. The upper surface of the protrusion and the upper surface of the support are on the same plane. The metal sheet for a vapor chamber according to any one of claims 1 to 4.

6. the steam flow path portion includes a steam flow path recess formed in the first surface, a depth of the vapor channel recess is greater than a depth of the injection channel recess in the first region; The metal sheet for a vapor chamber according to any one of claims 1 to 5.

7. the steam flow path portion includes a steam flow path recess formed in the first surface, a depth of the vapor channel recess is the same as a depth of the injection channel recess in the first region and a depth of the injection channel recess in the second region; The metal sheet for a vapor chamber according to any one of claims 1 to 5.

8. the steam flow path portion includes a steam flow path recess formed in the first surface, a depth of the vapor flow passage recess is shallower than a depth of the injection flow passage recess in the first region and a depth of the injection flow passage recess in the second region; The metal sheet for a vapor chamber according to any one of claims 1 to 5.

9. The steam flow path portion includes a plurality of steam passages extending in a first direction, and a communication steam passage extending in a second direction perpendicular to the first direction, the communication steam passages being in communication with each other, The injection flow path recess communicates with the steam communication passage. The metal sheet for a vapor chamber according to any one of claims 1 to 8.

10. A vapor chamber having a sealed space in which a hydraulic fluid is sealed, A vapor chamber comprising the metal sheet for a vapor chamber according to any one of claims 1 to 9.

11. Housing and a device contained within the housing; and An electronic device comprising: a vapor chamber according to claim 10 in thermal contact with the device.

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