JP7472947B2 - Vapor chambers, electronic devices and metal sheets for vapor chambers - Google Patents

Description

The present invention relates to a vapor chamber, an electronic device, and a metal sheet for a vapor chamber.

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, there has been a demand for thinner heat dissipation members in order to make mobile terminals thinner, and vapor chambers, which 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.

More specifically, the working fluid in the vapor chamber receives heat from the device in the part close to the device (evaporation part) and evaporates into vapor, and the vapor then moves to a position away from the evaporation part 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 part, 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.

JP 2016-50682 A

In flat heat exchangers such as vapor chambers, an injection passage is provided in the metal sheet for injecting the working fluid after degassing. However, if the width of the injection passage is made narrower than the steam passage or the wick groove, 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 fluid into the vapor chamber, resulting in a problem of reduced workability.

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 of the vapor chamber and injection of working fluid into the vapor chamber to be performed in a short time when manufacturing the vapor chamber.

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;
I will provide a.

In the vapor chamber described above,
A plurality of support columns are provided protruding from the injection channel recess.
This may be done.

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.

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.

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.

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.

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.

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

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 vapor flow path recess and the liquid flow path portion.
This may be done.

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.
I will provide a.

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;
I will provide a.

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 an injection flow path recess formed on the first surface for injecting the liquid working fluid, the width of the injection flow path recess being wider than the width of the vapor passage;
I will provide a.

According to the present invention, when manufacturing a vapor chamber, the degassing process inside the vapor chamber and the injection of the working fluid into the vapor chamber can be performed in a short time.

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

One embodiment of the present invention will now be described with reference to the drawings. Note that in the drawings attached to this specification, the scale and aspect ratios have been appropriately altered and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

In addition, terms such as "parallel," "orthogonal," and "same," which specify shapes, geometric conditions, and physical characteristics and their degrees, as well as lengths, angles, and values of physical characteristics, used in this specification, are to be interpreted without being bound by their strict meanings, but also to include 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 shown in a regular manner for clarity, but the shapes of the parts may differ from each other as long as the functions can be expected without being bound by strict meanings. In the drawings, boundaries 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 as long as the desired joint performance can be expected.

(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 to cool a device D as 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 mobile terminals and tablet terminals.

Here, first, the electronic device E equipped with the vapor chamber 1 according to the present embodiment will be described using a tablet terminal as an example. As shown in FIG. 1, the electronic device E (tablet terminal) includes a housing H, a device D housed in the housing H, and a vapor chamber 1. In the electronic device E shown in FIG. 1, a touch panel display TD is provided on the front surface of the housing H. The vapor chamber 1 is housed in the housing H and 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 in use. 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.

Next, the vapor chamber 1 in this embodiment will be described. The vapor chamber 1 has a sealed space 3 in which a working liquid 2 is sealed, 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.

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 rectangular as shown in FIG. 2. In this case, the vapor chamber 1 has four linear outer edges 1a, 1b forming an outer planar contour. Two of the outer edges 1a are formed along the first direction X described below, and the remaining two outer edges 1b are formed along the second direction Y described below. 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.

2 and 3, the vapor chamber 1 includes a lower metal sheet 10 (first metal sheet or second metal sheet, vapor chamber metal sheet) and an upper metal sheet 20 (second metal sheet or first metal sheet, vapor chamber metal sheet) 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 (the surface on the lower metal sheet 10 side) superimposed on the upper surface 10a (the surface on the upper metal sheet 20 side) of the lower metal sheet 10, and an upper surface 20b provided on the opposite side to the lower surface 20a. The device D, which is the object to be cooled, is attached to the lower surface 10b of the lower metal sheet 10 (particularly the lower surface of the evaporation section 11, which will be described later).

Between the lower metal sheet 10 and the upper metal sheet 20, a sealed space 3 is formed in which the working fluid 2 is sealed. In this embodiment, the sealed space 3 has a steam flow path section 80 (lower steam flow path recess 12 and upper steam flow path recess 21 described later) 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. Examples of the working fluid 2 include pure water, ethanol, methanol, acetone, etc.

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 section 4, which will be described later, are both formed in a rectangular shape in a plan view, but this is not limited to this. Here, a 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.

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.

As shown in FIG. 2, the vapor chamber 1 further includes an injection section 4 at one of a pair of ends in the first direction X for injecting the working fluid 2 into the sealed space 3. The injection section 4 includes a lower injection protrusion 16 protruding laterally from the end face of the lower metal sheet 10 (the face corresponding to the outer edge 1b in FIG. 2) and an upper injection protrusion 25 protruding laterally from the end face of the upper metal sheet 20 (the face corresponding to the outer edge 1b in FIG. 2). A lower injection flow path recess 17 (injection flow path recess) is formed on the upper face of the lower injection protrusion 16 (the face corresponding to the upper face 10a of the lower metal sheet 10) (see FIG. 4). On the other hand, no recess is formed on the lower face of the upper injection protrusion 25 (the face corresponding to the lower face 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 is connected to 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, 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 is not limited to this and can be provided at any position. In addition, two or more injection parts 4 may be provided.

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 mainly to allow the steam generated in the evaporation section 11 to pass therethrough.

The evaporation section 11 is disposed in the lower steam flow path recess 12, and the steam in the lower steam flow path recess 12 diffuses away from the evaporation section 11, and most of the steam is transported toward the peripheral portion, which has 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 in which it is provided in 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.

In this embodiment, as shown in FIG. 3 and FIG. 4, a plurality of lower flow path walls 13 (first flow path protrusions) protruding upward (perpendicular to the bottom surface 12a) from the bottom surface 12a (described later) of the lower steam flow path recess 12 of the lower metal sheet 10 are provided. In this case, the lower flow path walls 13 protrude in a direction perpendicular to the bottom surface 12a, but this is not limited thereto, and may protrude in a direction that is not perpendicular to the bottom surface 12a. In this embodiment, an example is shown in which the lower flow path 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 path walls 13 include an upper surface 13a (abutment surface, protruding end surface) that abuts against the lower surface 22a of the upper flow path wall 22 described later. The upper surface 13a is a surface that is not etched by the etching process described later, and is formed on the same plane as the upper surface 10a of the lower metal sheet 10. Additionally, the lower flow path walls 13 are spaced apart at equal intervals and arranged parallel to each other.

As shown in Figs. 3 and 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 may be any shape 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.

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

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 distance between 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 vertical direction in FIG. 4, for example. In addition, it is preferable that 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 at least 10 μm 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 steam 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.

As shown in Figures 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 to surround the sealed space 3, particularly the lower steam flow path recess 12, and defines the sealed space 3. In addition, lower alignment holes 15 are provided at the four corners of the lower peripheral wall 14 in a plan view to position the lower metal sheet 10 and the upper metal sheet 20.

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 into 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 to this and may be formed at the center of the width direction (second direction Y) of the lower metal sheet 10.

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 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 of the lower steam flow path recess 12).

A bank portion 51 is formed on each side of the lower injection flow path recess 17 in the width direction (second direction Y). The bank portion 51 constitutes the wall portions on both sides of the lower injection flow path recess 17. The bank portion 51 is an area 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 length (first direction X distance) 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 (second direction Y distance) 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 vertical dimension 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 less likely to occur during work such as evacuation. In addition, 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 easier. By making w9 1 mm or more, the cross-sectional area of the injection flow path becomes wider, allowing degassing and the injection of hydraulic fluid 2 to be performed efficiently and quickly, and by making it 10 mm or less, leaks after crimping are less likely to occur.

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. In addition, it is preferable that the width w9 of the lower injection flow path recess 17 is 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, preferably 1 mm to 3 mm. In addition, for example, when the width w7 is 2 mm, the width w9 may be 3.5 mm to 10 mm, 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.

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.

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

The inlet region 52 is an area into which the liquid working fluid 2 is poured from the opening 17a, and is directly connected to the opening 17a and has a substantially flat bottom surface 17b with no irregularities.

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 multiple supports 55 in this manner, an internal space in 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.

The pillars 55 are formed in a plurality of columns (in this embodiment, four in the first direction X and two 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 channel recess 17. Each pillar 55 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. In addition, the shapes of the multiple pillars 55 are the same, but the shapes of the multiple pillars 55 may be different from each other. The width w10 of each pillar 55 may be, for example, 0.1 mm to 2 mm. Furthermore, the interval p1 between the pillars 55 may be, for example, 0.1 mm to 2 mm, and the interval p2 between the pillars 55 and the bank portion 51 may be, for example, 0.1 mm to 2 mm. By making w10 0.1 mm or more, the strength of the pillars is improved, and by making it 2 mm or less, the degassing work and the injection work of the working fluid 2 can be performed efficiently and quickly. By making p1 and p2 0.1 mm or more, degassing and injection 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 during joining is less likely to occur, and the cross-sectional area of the injection flow path can be prevented from becoming narrow.

The crimped area 54 is an area that is closed and sealed by crimping (pressing and plastically deforming) after the hydraulic fluid 2 is injected into the sealed space 3. This crimped area 54 has a plurality of protrusions 56 that protrude upward within the lower injection flow path recess 17. Each protrusion 56 is an area 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 a plurality of protrusions 56 in the crimped area 54 in this way, the sealed space 3 into which the hydraulic fluid 2 has been injected can be sealed more reliably.

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 passage 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 narrower than the interval p1 between the support 55. As described above, the width w9 of the lower injection flow passage 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 area 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.

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 steam 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, 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, preferably 1.5 mm to 6 mm. In this way, by making the depth d1 of the lower injection flow recess 17 deeper than the depth h0 of the lower steam flow recess 12, degassing from the sealed space 3 to the lower injection flow recess 17 and injection of the working fluid 2 from the lower injection flow recess 17 to the sealed space 3 can be performed quickly. The depth d1 of the lower injection flow recess 17 refers to the depth of the deepest part of the lower injection flow 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 recess 17. In this embodiment, the depth d1 of the lower injection flow recess 17 corresponds to the depth of the lower injection flow recess 17 in the inlet region 52 and the intermediate region 53. The depth h0 of the lower steam flow recess 12 refers to the depth of the deepest part of the lower steam flow recess 12.

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, this is not limited to the above, 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 if 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.

Next, the configuration of the upper metal sheet 20 will be described. In this embodiment, the upper metal sheet 20 differs from the lower metal sheet 10 in that the liquid flow path section 30 described below 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.

3 and 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 where the temperature is relatively low. Also, as shown in FIG. 3, a housing member Ha that constitutes a part of the housing of a mobile terminal or the like is arranged 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.

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) are provided in the upper steam flow passage recess 21 of the upper metal sheet 20, protruding downward (perpendicular to the bottom surface 21a) from the bottom surface 21a of the upper steam flow passage recess 21. In this embodiment, an example is shown in which the upper flow passage wall 22 extends in an elongated shape along the first direction X (left-right direction in Fig. 5) of the vapor chamber 1. The upper flow passage wall 22 includes 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 lower flow passage wall 13 described above). In addition, the upper flow passage walls 22 are arranged parallel to each other at equal intervals.

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 portion 22. The upper steam passages 83 extend in an elongated shape along the first direction X and are arranged parallel to each other. Both ends of each upper steam passage 83 communicate with the 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 way, the steam of the working fluid 2 flows around each upper passage wall portion 22 (the upper steam passage 83 and the upper communication steam passage 84) and is transported toward the peripheral portion of the upper steam passage recess 21, suppressing the flow of the steam from being obstructed. 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 may be any shape that 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., or may be different.

The upper flow passage wall 22 is arranged to overlap the corresponding lower flow passage wall 13 of the lower metal sheet 10 in a planar view, improving the mechanical strength of the vapor chamber 1. In addition, the upper steam passage 83 is formed to overlap the corresponding lower steam passage 81 in a planar view. Similarly, the upper communication steam passage 84 is formed to overlap the corresponding lower communication steam passage 82 in a planar view.

The width and height of the upper flow passage wall 22 are preferably the same as the width w0 and height h0 of the lower flow passage wall 13 described above. Here, the bottom surface 21a of the upper steam flow passage recess 21 can be called a ceiling surface in 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 innermost surface of the upper steam flow passage recess 21, it is referred to as the bottom surface 21a in this specification.

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 to surround the sealed space 3, particularly the upper steam flow path recess 21, and defines the sealed space 3. In addition, 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 to overlap with each lower alignment hole 15 described above when temporarily fastening as described below, and is configured to enable positioning of the lower metal sheet 10 and the upper metal sheet 20.

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. The upper injection protrusion 25 is formed in 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.

The lower surface of the upper injection protrusion 25 does not have an injection flow path recess. Therefore, the upper injection protrusion 25 is formed in a flat shape without any irregularities as a whole. In other words, the upper injection protrusion 25 is an area that is not etched in its entirety by the etching process described below, and the lower surface of the upper injection protrusion 25 is formed on the same plane as the lower surface 20a of the upper metal sheet 20.

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

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 abutted against 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 abutted against 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 portion 13 and the upper flow path wall portion 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.

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.

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 above-mentioned sealed space 3, and is connected to 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 lower flow path walls 13 that do not have a liquid flow path portion 30.

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 a communication groove 32 that connects 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.

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 the main flow groove 31 and the 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 adjacent protrusions 33 in the second direction Y.

It is preferable that the width (dimension in the second direction Y) w1 of the mainstream groove 31 is larger than the width (dimension in the second direction Y) w2 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, 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.

The depth h1 of the mainstream groove 31 is preferably smaller than the height h0 of the lower flow path wall 13 (see FIG. 3) described above. In this case, the capillary action of the mainstream groove 31 can be enhanced. For example, the depth h1 of the mainstream groove 31 is preferably about half the height h0 of the lower flow path wall 13, and may be 5 μm to 200 μm.

Moreover, 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 perform 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.

The depth (not shown) of the connecting groove 32 may be shallower than the depth of the main groove 31 depending on its width w3. For example, the depth of the connecting 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 same applies to the cross-sectional shape of the connecting groove 32.

As shown in FIG. 9, the liquid flow path section 30 is formed on the upper surface 13a of the lower flow path wall section 13 of the lower metal sheet 10. On the other hand, in this embodiment, the lower surface 22a of the upper flow path wall section 22 of the upper metal sheet 20 is formed flat. As a result, each mainstream groove 31 of the liquid flow path section 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 section 22, and the capillary action at these corners 37 can be enhanced.

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.

The shape of the liquid flow path portion 30 of the lower metal sheet 10 is not limited to the above.

For example, as shown in FIG. 10, the liquid flow path section 30 may have a plurality of main grooves 31 extending parallel to each other, and an elongated convex portion 33A formed between adjacent main 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 the liquid working fluid 2 to be efficiently transported in each main groove 31 toward the evaporation section 11. Although not shown, a communication groove may be provided in a part of the convex portion 33A, and this communication groove may connect each main groove 31 to the lower steam flow path recess 12 or the upper steam flow path recess 21.

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. In FIG. 3, the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 are shown as being 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 do not have to be equal.

Next, the operation of this embodiment configured as described above will be explained. First, the manufacturing method of the vapor chamber 1 will be explained using Figures 11(a)-(c) and Figures 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 Figures 12(a)-(c) show the same cross section as the cross section in Figure 3.

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

Next, as shown in FIG. 11(b), a resist film 41 is formed by photolithography on each of the upper surface Ma and the 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.

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. After that, 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 connecting groove 32 of the liquid flow passage section 30 is narrow, the etching liquid does not wrap around much. Therefore, the depth of the main flow passage groove 31 and the connecting 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.

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 solution of ferric chloride, or a copper chloride-based etching solution such as an aqueous solution of copper chloride.

In addition, the lower steam flow path recess 12 may be first 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 by a separate etching process (second half etching process).

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

Next, as shown in FIG. 12(a), in the temporary fixing process, 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 placed opposite each other and temporarily fixed.

In this case, the lower metal sheet 10 and the upper metal sheet 20 are first 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. Next, 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, ultrasonic waves may be irradiated to ultrasonically bond the lower metal sheet 10 and the upper metal sheet 20 to fix them. Furthermore, an adhesive may be used, but it is preferable to use an adhesive that does not have an organic component or has a small organic component. In this way, the lower metal sheet 10 and the upper metal sheet 20 are fixed in position.

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 the direction of contact and heated to bond 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 the metal sheets 10 and 20 can be prevented 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 Figures 2 and 4) of the lower injection protrusion 16 and the upper injection protrusion 25 (see Figures 2 and 5) form an injection flow path for the working fluid 2 that communicates 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 to form a joining 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.

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 vacuumed 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 the 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 vacuuming 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.

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 the 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 performed normally in the vapor chamber 1 (for example, see JP 2004-301475 A).

In contrast, in this embodiment, as described above, the width w9 of the lower injection flow channel recess 17 that constitutes the injection flow channel is wider than the width w7 of the lower steam passage 81. This allows the injection flow channel to be evacuated to reduce the pressure in the sealed space 3, and the working fluid 2 to be injected from the injection flow channel into the sealed space 3, to be performed efficiently and in a short time. This prevents non-condensable gas from remaining in the sealed space 3, prevents a decrease in heat transport efficiency, and as a result, improves yield.

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 part 4, laser irradiation or brazing may be performed after the crimping region 54 is crimped. In addition, after the injection flow path is sealed, the injection part 4 may be cut at any position on the opening 17a side of the crimping region 54 in the injection part 4.

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

In this 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 together.

Next, we will explain how the vapor chamber 1 operates, i.e., how the device D is cooled.

The vapor chamber 1 obtained as described above is installed in the 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 walls of the sealed space 3, i.e., the walls of the lower steam flow path recess 12, the walls of the upper steam flow path recess 21, and the walls of the liquid flow path section 30, due to its surface tension.

When the device D generates heat in this state, the working fluid 2 present in the evaporation section 11 of the lower steam flow passage recess 12 receives heat from the device D. The received heat is absorbed as latent heat, and the working fluid 2 evaporates (vaporizes), generating steam of the working fluid 2. Most of the generated steam diffuses within the lower steam flow passage recess 12 and the upper steam flow passage recess 21 that form the sealed space 3 (see the solid arrows in Figure 4). The steam within the upper steam flow passage recess 21 and the lower steam flow passage recess 12 leaves the evaporation section 11, and most of the steam is transported toward the periphery of the vapor chamber 1, which has a relatively low temperature. The diffused steam 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 steam is transferred to the outside air via the housing member Ha (see Figure 3).

The steam condenses by losing the latent heat absorbed in the evaporation section 11 by dissipating heat to the lower metal sheet 10 and the upper metal sheet 20. The condensed liquid working fluid 2 adheres to the wall surface of the lower steam flow recess 12 or the wall surface of the upper steam flow recess 21. Here, since the working fluid 2 continues to evaporate in the evaporation section 11, the working fluid 2 in the part of the liquid flow 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 steam flow recess 12 and the wall surface of the upper steam flow recess 21 moves toward the liquid flow section 30 and enters the liquid flow section 30. Therefore, the working fluid 2 filled in the liquid flow section 30 obtains a driving force toward the evaporation section 11 due to the capillary action of each mainstream groove 31, and is smoothly transported toward the evaporation section 11.

The working liquid 2 that reaches the evaporation section 11 receives heat from the device D again and evaporates. In this way, the working liquid 2 circulates through the vapor chamber 1 while repeatedly changing phases, i.e., evaporating and condensing, and transfers and releases the heat of the device D. As a result, the device D is cooled.

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 allows efficient and rapid operation of evacuating the injection flow path to degas the sealed space 3 and then injecting the working fluid 2 into the sealed space 3 during the manufacture of the vapor chamber 1. In particular, this effect can be obtained significantly when the width w9 of the lower injection flow path recess 17 is 1.5 times or more the width w7 of the lower steam passage 81.

In addition, according to this embodiment, since multiple support pillars 55 are protruding from the lower injection flow path recess 17, deformation of the lower injection flow path recess 17 can be suppressed. This prevents the deformation of the lower injection flow path recess 17 from interfering with the degassing operation in the sealed space 3 or the injection operation of the working fluid 2 into the sealed space 3 during the manufacture of the vapor chamber 1, and allows the degassing and injection operations to be performed efficiently.

In addition, according to this embodiment, a crimped area 54 is formed in the lower injection flow channel recess 17, and this crimped area 54 has a number of protrusions 56. These protrusions 56 are crushed when the crimped area 54 is crimped after the hydraulic fluid 2 is injected into the sealed space 3. This makes it possible to seal the sealed space 3 even more reliably.

In addition, according to this embodiment, the depth d1 of the lower injection flow path recess 17 is deeper than the depth h0 of the steam flow path recess 12, so that 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 steam 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 when manufacturing the vapor chamber 1.

Furthermore, according to this embodiment, the liquid flow path section 30 has a plurality of main grooves 31 extending parallel to each other, and a communication groove 32 that connects 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.

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

In addition, since the pressure inside the sealed space 3 is reduced 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 that causes them to be recessed inward in the thickness direction. Here, if the communication grooves 32 are connected to the same positions on both sides of the longitudinal direction of each mainstream groove 31, it is possible 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 mainstream 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 multiple protrusions 33 arranged in a staggered pattern 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 mainstream grooves 31, the flow path cross-sectional area of the mainstream grooves 31 can be secured, and the flow of the working fluid 2 is prevented from being obstructed.

Next, various 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 designated by the same reference numerals and detailed descriptions will be omitted.

(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.

(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 passage recess 12, and the liquid flow passage portion 30 is provided on the upper surface 10a of the lower metal sheet 10. The liquid flow passage portion 30 is formed not only in the region of the upper surface 10a facing the upper flow passage wall portion 22, but also in the region facing the upper vapor flow passage recess 21. Although not shown in FIG. 14, 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 upper vapor flow passage recess 21. In this case, the number of main stream grooves 31 constituting the liquid flow passage 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 passage 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. In addition, the thickness of the lower metal sheet 10 can be reduced, thereby making it possible to reduce the overall thickness of the vapor chamber 1.

(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.

(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 FIG. 1 to FIG. 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.

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.

The second embodiment shown in Figures 17 to 19 is different 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 connects the steam flow path recess and the liquid flow path portion is provided in the intermediate metal sheet. The other configurations are substantially the same as those of the first embodiment shown in Figures 1 to 16. Note that in Figures 17 to 19, the same parts as those of the first embodiment shown in Figures 1 to 16 are given the same reference numerals and detailed description is omitted.

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, a lower metal sheet 10, an intermediate metal sheet 70, and an upper metal sheet 20 are stacked 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. Note that in FIG. 17, the illustration of 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.

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 bonded by diffusion bonding, and the intermediate metal sheet 70 and the upper metal sheet 20 are bonded 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 thickness of the intermediate metal sheet 70 is, for example, 10 μm to 300 μm.

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 connected 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).

The lower metal sheet 10 including the lower steam flow path recess 12 and the liquid flow path section 30 can be configured similarly to the lower metal sheet 10 in the first embodiment shown in Figures 1 to 16. For this reason, a detailed description will be omitted here.

In this embodiment, the upper metal sheet 20 does not have 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. Within the upper steam flow path recess 21, a plurality of upper flow path protrusions 90 (second flow path protrusions) are provided that protrude downward (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 process and where the material of the upper metal sheet 20 remains.

As shown in FIG. 17, the upper flow passage 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.

As shown in FIG. 18, in this embodiment, the upper flow passage protrusions 90 are arranged in a staggered pattern in a plan view. This allows the vapor of the working fluid 2 to flow around the upper flow passage protrusions 90, preventing the flow of the vapor from being obstructed. The planar shape of the lower surface of the upper flow passage protrusions 90 is circular, which also prevents the flow of the vapor of the working fluid 2 from being obstructed. The planar shape of the upper flow passage protrusions 90 is not limited to a circular shape as long as it prevents the flow of the vapor of the working fluid 2 from being obstructed.

As shown in FIG. 19, the intermediate metal sheet 70 is provided with communication holes 71 (communication sections) that connect the upper steam flow path recess 21 and the liquid flow path section 30. The communication holes 71 penetrate the intermediate metal sheet 70 and form part of the sealed space 3 described above. In addition, the communication holes 71 are arranged between the adjacent upper flow path protrusions 90 in a plan view, and the communication holes 71 are arranged in a staggered pattern in a plan view.

As shown in FIG. 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 condensed from the vapor of the working fluid 2 in the upper vapor flow path recess 21 passes through the communication holes 71 and enters the main groove 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 to the upper vapor flow path recess 21.

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, it 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 circular. 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.

As shown in FIG. 19, in this embodiment, the communication hole 71 overlaps with a portion of one lower steam passage 81 and a portion 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 allows the flow path cross-sectional area of the communication hole 71 to be increased, and the steam of the working fluid 2 can be smoothly diffused to the upper steam flow path recess 21. Note that the communication hole 71 may overlap with a portion of each of three or more lower steam passages 81 to communicate these lower steam passages 81.

As shown in FIG. 19, the intermediate metal sheet 70 is provided with intermediate alignment holes 72 for positioning the metal sheets 10, 20, and 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, and 70.

In this embodiment, the injection section 4 may be formed in the same manner as the injection section 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.

The intermediate metal sheet 70 has an intermediate injection protrusion 75 that protrudes laterally from the end face. 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 way as the upper injection protrusion 25.

However, this is not limited to the above. 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 underside of the upper injection protrusion 25. Alternatively, instead of such an injection section 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.

In addition, in the vapor chamber 1 according to this embodiment, the lower steam flow path recess 12 and the liquid flow path section 30 of the lower metal sheet 10 and the upper steam flow path recess 21 of the upper metal sheet 20 can be formed in the same manner as in the first embodiment shown in Figures 1 to 16. In addition, 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.

Thus, according to this embodiment, an intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20, an upper steam flow path recess 21 is provided on the lower surface 20a of the upper metal sheet 20, and a 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 composed of three metal sheets 10, 20, and 70, the working liquid 2 can be circulated inside the vapor chamber 1 while repeatedly changing phases 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 connected, the vapor of the working liquid 2 can be smoothly diffused, and the heat transport efficiency can be improved.

In addition, according to this embodiment, as in the first embodiment shown in Figures 1 to 16, the width w9 of the lower injection flow passage recess 17 is wider than the width w7 of the lower steam passage 81. This allows the injection flow passage to be evacuated to degas the sealed space 3 during the manufacture of the vapor chamber 1, and the working fluid 2 to be injected into the sealed space 3 thereafter to be efficiently and quickly performed.

In the example shown in FIG. 17, the cross-sectional shape of the lower steam flow passage recess 12 and the cross-sectional shape of the upper steam flow passage recess 21 are formed in a rectangular shape. However, this is not limited to this, and the cross-sectional shapes of the steam flow passage recesses 12, 21 may be formed in a curved shape. The same applies to the main groove 31 and the connecting groove 32 of the liquid flow passage section 30.

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.

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. 20 and 21. FIG.

The third embodiment shown in Figures 20 and 21 differs mainly in that the upper flow passage protrusion and the communication hole extend in an elongated shape along the first direction, and the other configurations are substantially the same as those of the second embodiment shown in Figures 17 to 19. Note that in Figures 20 and 21, the same parts as those of the second embodiment shown in Figures 17 to 19 are given the same reference numerals and detailed descriptions are omitted.

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

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

In this embodiment, the communication hole 71 overlaps one lower steam passage 81 of the lower steam passage recess 12 in a plan view. The communication hole 71 also overlaps the upper steam passage 83 of the upper steam passage recess 21, which overlaps the lower steam passage 81 in a plan view. In other words, the communication hole 71 is provided between the lower steam passage 81 and the upper steam passage 83, which overlap each other, so as to overlap them. Therefore, the steam of the working fluid 2 in the lower steam passage 81 can quickly reach the upper steam passage 83 through the communication hole 71 and can be smoothly diffused into the upper steam passage 83.

Thus, according to this embodiment, an intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20, an upper steam flow path recess 21 is provided on the lower surface 20a of the upper metal sheet 20, and a 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 connects 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 inside the vapor chamber 1 while repeatedly changing phases in the sealed space 3, and the heat of the device D can be transferred and released.

In addition, according to this embodiment, as in the first embodiment shown in Figures 1 to 16, the width w9 of the lower injection flow passage recess 17 is wider than the width w7 of the lower steam passage 81. This allows the injection flow passage to be evacuated to degas the sealed space 3 during the manufacture of the vapor chamber 1, and the working fluid 2 to be injected into the sealed space 3 thereafter to be efficiently and quickly performed.

(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.

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. The other configurations are substantially the same as those of the second embodiment shown in Figures 17 to 19. Note that in Figures 22 to 25, the same parts as those of the second embodiment shown in Figures 17 to 19 are given the same reference numerals and detailed description is omitted.

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 in this embodiment is formed 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 in this embodiment is sometimes referred to as a wick sheet. The steam flow path section 80 and the liquid flow path section 30 are connected to allow the working liquid 2 to return.

23 and 24, the intermediate metal sheet 70 has a frame body 73 formed in a rectangular frame shape in a plan view, and a plurality of land portions 74 provided in the frame body 73. The frame body 73 and the land portion 74 are portions of the intermediate metal sheet 70 that are not etched when the intermediate metal sheet 70 is etched, and the material of the intermediate metal sheet 70 remains. 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 73 via a support portion not shown. The support portion is formed so as to suppress the obstruction of the flow of the steam of the working fluid 2 flowing in the intermediate steam passage 85 described later. 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.

The steam flow path section 80 includes a plurality of intermediate steam passages 85 (third steam passages, steam passages) partitioned by land sections 74. The intermediate steam passages 85 extend in an elongated shape along the first direction X and are arranged parallel to each other. Both ends of each intermediate steam passage 85 are connected to an intermediate communication steam passage 86 extending in an elongated shape along the second direction Y, and each intermediate steam passage 85 is connected through the intermediate communication steam passage 86. In this way, 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 path section 80, suppressing the flow of 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 is any shape as long as it can diffuse the steam of the working fluid 2. The same applies to the intermediate steam passage 86. The intermediate steam passage 85 and the intermediate 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 a cross-sectional shape similar to that of the communication hole 71.

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 applies to the width (dimension in the first direction X) of the intermediate communication steam passage 86.

The liquid flow path section 30 is provided in the land portion 74 on the lower surface 70a of the intermediate metal sheet 70. In other words, the liquid flow path section 30 is provided on the lower surface of the land portion 74.

In this 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. In this embodiment, the thickness of the lower metal sheet 10 and the thickness of the upper metal sheet 20 are, for example, 8 μm to 100 μm.

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. After that, 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.

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 upper surface of the lower injection protrusion 16 is formed in a flat shape without the lower injection flow path recess 17. 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.

The intermediate injection protrusion 75 and the intermediate injection flow path section 76 can be formed in the same manner as the lower injection protrusion 16 and the lower injection flow path 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 flow path section 76 may have the same width w9 as the lower injection flow path recess 17.

In this embodiment, the width w9 of the intermediate injection flow passage portion 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. In addition, it is preferable that the width w9 of the intermediate injection flow passage portion 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, preferably 1 mm to 3 mm. In addition, for example, when the width w6 is 2 mm, the width w9 may be 3.5 mm to 10 mm, preferably 1 mm to 6 mm. In this way, by making the width w9 of the intermediate injection flow passage portion 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.

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.

Thus, according to this embodiment, an intermediate metal sheet 70 is interposed between the lower metal sheet 10 and the upper metal sheet 20, a vapor flow path section 80 is provided on the upper surface 70b of the intermediate metal sheet 70, and a liquid flow path section 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, and 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 the heat of the device D.

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 portion 80 and the liquid flow path portion 30. As a result, it is possible to easily manufacture the vapor chamber 1. 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.

In addition, according to this embodiment, as in the first embodiment shown in Figures 1 to 16, the width w9 of the intermediate injection flow passage portion 76 is wider than the width w6 of the intermediate steam passage 85. This allows the operation of evacuating the injection flow passage to degas the sealed space 3 during the manufacture of the vapor chamber 1, and the operation of injecting the working fluid 2 into the sealed space 3 thereafter, to be performed efficiently and quickly.

In addition, 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 reduces 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 main groove 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 to the vapor flow path section 80.

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, this is not limited to the above, 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, the number of flow paths for transporting the liquid working fluid 2 to the evaporation section 11 or the portion of the intermediate metal sheet 70 closer to the evaporation section 11 can be increased, and the transport efficiency of the liquid working fluid 2 can be improved. This allows the heat transport efficiency of the vapor chamber 1 to be improved.

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 this, 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, such as the lower steam flow path recess 12 shown in Figures 1 to 16, or 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 connects the steam flow path section 80 to the liquid flow path section 30.

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.

The present invention is not limited to the above-described embodiments and modifications, and in the implementation stage, the components can be modified without departing from the gist of the invention. Various inventions can be created by appropriate combinations of the multiple components disclosed in the above-described embodiments and modifications. Some components may be deleted from all the components shown in each embodiment and modification. In the above-described embodiments and modifications, the configuration of the lower metal sheet 10 and the configuration of the upper metal sheet 20 may be interchanged.

REFERENCE SIGNS LIST 1 vapor chamber 2 working fluid 10 lower metal sheet 12 lower vapor flow passage recess 17 lower injection flow passage recess 20 upper metal sheet 21 upper vapor flow passage recess 30 liquid flow passage section 31 main flow groove 32 connecting groove 33 convex section 54 crimped area 55 support 56 projection 70 intermediate metal sheet 70a lower surface 70b upper surface 71 communicating hole 76 intermediate injection flow passage section 80 vapor flow passage section 81 lower vapor passage 85 intermediate vapor passage 90 upper flow passage protrusion D device E electronic device H housing P intersection Q buffer area X first direction Y second direction

Claims (9)

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 liquid working fluid is formed in the first surface;
the injection flow passage recess has one end communicating with the vapor flow passage portion and the other end having an opening;
a depth of the injection flow path concave portion in a first region located on the steam flow path portion side is shallower than a depth of the injection flow path concave portion in a second region located on the opening side of the first region,
the steam flow path portion includes a steam flow path recess formed in the first surface,
a depth of the deepest portion of the injection channel recess is greater than a depth of the deepest portion of the vapor channel recess;
The thickness of the metal sheet for the vapor chamber minus the depth of the deepest part of the vapor flow path recess is 10 μm or more.
Metal sheet for vapor chamber. a depth of the injection channel recess in the first region is shallower than a depth of the vapor channel recess;
The metal sheet for a vapor chamber according to claim 1. the steam flow passage recess 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.
3. The metal sheet for a vapor chamber according to claim 1 or 2. A plurality of protrusions are formed in the first region of the injection channel recess,
A plurality of support columns are formed in the second region of the injection channel recess;
The upper surfaces of the plurality of protrusions and the upper surfaces of the plurality of posts are on the same plane.
The metal sheet for a vapor chamber according to any one of claims 1 to 3. The deepest portion of the injection channel recess is located in the second region.
The metal sheet for a vapor chamber according to any one of claims 1 to 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 recess through which vapor of the working fluid passes is formed in the first surface,
an injection flow path recess for injecting the liquid working fluid is formed in the first surface;
the injection flow passage recess has one end communicating with the vapor flow passage recess and has the other end provided with an opening;
a depth of the deepest portion of the injection channel recess is greater than a depth of the deepest portion of the vapor channel recess;
The thickness of the metal sheet for the vapor chamber minus the depth of the deepest part of the vapor flow path recess is 10 μm or more.
Metal sheet for vapor chamber. the steam flow passage recess 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 claim 6. 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 7. Housing and
A device contained within the housing; and
10. An electronic device comprising: a vapor chamber according to claim 8 in thermal contact with the device.

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