JP6917006B2 - Manufacturing method of vapor chamber, metal sheet for vapor chamber and vapor chamber - Google Patents

Description

The present invention relates to a vapor chamber having a sealed space in which a working fluid is sealed, a metal sheet for the vapor chamber, and a method for producing the vapor chamber.

A vapor chamber (also referred to as a heat pipe) is used for cooling a device that generates heat, such as a central processing unit (CPU) used in a mobile terminal such as a mobile terminal or a tablet terminal (for example, a patent document). 1 to 4). A hydraulic fluid is sealed in the vapor chamber, and the hydraulic fluid absorbs the heat of the device and releases it to the outside to cool the device.

More specifically, the working fluid in the vapor chamber receives heat from the device at a portion close to the device (evaporation part) and evaporates to vapor, and then the vapor moves to a position away from the evaporation part. It cools and condenses into a liquid. The liquefied working liquid passes through the flow path in the vapor chamber, is transported to the evaporation section, and receives heat again in the evaporation section to evaporate. In this way, the working fluid transfers heat of the device by refluxing in the vapor chamber while repeating phase change, that is, evaporation and condensation, and enhances heat transport efficiency.

Japanese Unexamined Patent Publication No. 11-31768 Japanese Unexamined Patent Publication No. 2007-21028 Japanese Unexamined Patent Publication No. 2015-59693 Japanese Unexamined Patent Publication No. 2016-17702

By the way, in the vapor chamber, the surface opposite to the surface on which the device is mounted is configured as a heat radiating surface. That is, the heat received from the device by the metal sheet constituting the vapor chamber is released to the outside from the heat radiating surface. Therefore, if there is a thermal resistance when heat is released from the heat radiating surface, it may be difficult to efficiently transport the heat.

The present invention has been made in consideration of such a point, and an object of the present invention is to provide a vapor chamber, a metal sheet for a vapor chamber, and a method for producing a vapor chamber, which can improve heat transport efficiency.

The present invention
A vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The space demarcation surface that defines the sealed space and
The heat receiving surface that receives heat from the cooled device and
A heat radiating surface provided on the side opposite to the heat receiving surface side with respect to the sealed space,
A vapor chamber, comprising a roughened portion provided on at least a part of the heat radiating surface and having a surface roughness larger than the surface roughness of the space defining surface.
I will provide a.

In the above-mentioned vapor chamber, the roughened portion may be provided on at least a part of the heat receiving surface.

Further, in the above-mentioned vapor chamber, the roughened portion may be roughened by the grain interface of the crystal of the material.

Further, in the above-mentioned vapor chamber, the roughened portion may be roughened by a plurality of electrodeposits.

Further, in the vapor chamber described above, an outer peripheral surface extending from the heat radiating surface to the heat receiving surface may be further provided, and the roughened portion may also be provided on the outer peripheral surface.

Further, in the above-mentioned vapor chamber, the first metal sheet having the heat receiving surface and the second metal sheet provided on the first metal sheet and having the heat radiating surface are further provided with the first metal sheet. The sealed space may be formed between the second metal sheet and the second metal sheet.

In addition, the present invention
A metal sheet for a vapor chamber for a vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The first surface on which at least a part of the sealed space is formed, and
The space demarcation surface that defines the sealed space and
A second surface provided on the side opposite to the first surface,
A metal sheet for a vapor chamber, comprising a roughened portion provided on at least a part of the second surface and having a surface roughness larger than the surface roughness of the space defining surface.
I will provide a.

In addition, the present invention
A method for manufacturing a vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
A preparatory step for preparing a first metal sheet to which the cooled device is attached and a second metal sheet, and
A demarcation surface forming step of forming a space demarcation surface that defines the sealed space on at least one of the first metal sheet and the second metal sheet.
The roughening process for forming the roughened portion and
A joining step of joining the first metal sheet and the second metal sheet to form the sealed space between the first metal sheet and the second metal sheet.
A sealing step of sealing the working fluid in the sealed space is provided.
The second metal sheet has a space-defining surface that defines a part of the sealed space, and a heat-dissipating surface that is provided on a side opposite to the side of the device to be cooled.
The roughened portion has a surface roughness larger than the surface roughness of the spatially defined surface.
A method for manufacturing a vapor chamber, wherein the roughened portion is formed on at least a part of the heat radiating surface in the step of forming the roughened portion.
I will provide a.

In the method for manufacturing a vapor chamber described above, the roughening step may be performed between the defining surface forming step and the joining step.

Further, in the above-mentioned method for manufacturing a vapor chamber, the roughening step may be performed after the encapsulation step.

Further, in the method for manufacturing a vapor chamber described above, in the roughening step, the roughened portion may be formed by half etching.

Further, in the method for manufacturing a vapor chamber described above, in the roughening step, a patterned resist film is formed on the heat radiating surface, and then the heat radiating surface is half-etched from the resist opening of the resist film. A roughened portion may be formed.

Further, in the method for manufacturing a vapor chamber described above, in the defining surface forming step, the space defining surface is formed by half etching, and the etching solution used in the roughening step is the etching used in the defining surface forming step. The erosion effect may be smaller than that of the liquid.

Further, in the method for manufacturing a vapor chamber described above, in the roughening step, the roughened portion may be formed by electroplating.

According to the present invention, the heat transport efficiency can be improved.

FIG. 1 is a top view showing a vapor chamber according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a cross-sectional view taken along the line BB of FIG. FIG. 4 is a cross-sectional view taken along the line CC of FIG. 5 (a) to 5 (d) are plan views showing an example of the plan shape of the roughened convex portion of the roughened portion shown in FIGS. 2 to 4. 6 (a) to 6 (e) are cross-sectional views showing an example of the cross-sectional shape of the roughened concave portion of the roughened portion shown in FIGS. 2 to 4. FIG. 7 is a diagram for explaining a step of preparing the upper metal sheet in the method for manufacturing the vapor chamber of FIG. 1. FIG. 8 is a diagram for explaining a first half etching step of the upper metal sheet in the method for manufacturing the vapor chamber of FIG. 1. FIG. 9 is a diagram for explaining a roughening step of the upper metal sheet in the method for manufacturing the vapor chamber of FIG. 1. FIG. 10 is a diagram for explaining a step of forming a resist film on the heat radiating surface of the upper metal sheet in the roughening step of FIG. FIG. 11 is a diagram for explaining the patterning step of the resist film of FIG. 10 in the roughening step of FIG. FIG. 12 is a diagram for explaining a second half etching step of the upper metal sheet in the roughening step of FIG. FIG. 13 is a diagram for explaining a step of removing the resist film in the roughening step of FIG. FIG. 14 is a diagram for explaining a temporary fixing step in the method for manufacturing the vapor chamber of FIG. 1. FIG. 15 is a diagram for explaining a joining process in the method for manufacturing the vapor chamber of FIG. 1. FIG. 16 is a diagram for explaining a process of filling a working liquid in the method for manufacturing a vapor chamber of FIG. FIG. 17 is a diagram showing a modified example of the cross section of the vapor chamber shown in FIG. FIG. 18 is a cross-sectional view of the vapor chamber according to the second embodiment of the present invention, which corresponds to the cross-sectional view taken along the line CC of FIG. FIG. 19 is a cross-sectional view of the vapor chamber according to the third embodiment of the present invention, which corresponds to the cross-sectional view taken along the line CC of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale, the aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

(First Embodiment)
A method for manufacturing a vapor chamber, a metal sheet for a vapor chamber, and a vapor chamber according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 17. Here, the vapor chamber 1 in the present embodiment has a sealed space 3 in which the working liquid 2 is sealed, and the working liquid 2 in the sealing space 3 repeats phase changes, so that a mobile terminal or a tablet terminal is used. This is a device for cooling a device (cooled device) that generates heat, such as a central processing unit (CPU) used in a mobile terminal or the like. The vapor chamber 1 is formed in a substantially thin flat plate shape.

As shown in FIGS. 1 to 4, the vapor chamber 1 according to the present embodiment has a lower metal sheet 10 (first metal sheet) and an upper metal sheet 20 (second metal sheet 20) provided on the lower metal sheet 10. Metal sheet) and. Of these, the device D, which is the object to be cooled, is attached to the lower surface of the lower metal sheet 10 (the heat receiving surface 10b described later, particularly the lower surface of the evaporation portion 11 described later).

The vapor chamber 1 has a space defining surface 3a that defines the sealed space 3, a heat receiving surface 10b that receives heat from the device D, and a heat radiating surface 20b that is provided on the side opposite to the heat receiving surface 10b side with respect to the sealed space 3. And a roughened portion 30. Of these, the heat receiving surface 10b corresponds to the lower surface of the lower metal sheet 10 described above, and the heat radiating surface 20b corresponds to the upper surface of the upper metal sheet 20 described above. Further, the vapor chamber 1 further includes a peripheral outer surface 5 extending from the heat radiating surface 20b to the heat receiving surface 10b. The peripheral outer surface 5 is composed of an outer surface 10c (described later) of the lower metal sheet 10 and an outer surface 20c (described later) of the upper metal sheet 20.

A sealing space 3 in which the hydraulic fluid 2 is sealed is formed between the lower metal sheet 10 and the upper metal sheet 20. Examples of the working fluid 2 include pure water, ethanol, methanol, acetone and the like.

The lower metal sheet 10 and the upper metal sheet 20 are joined by diffusion joining, which will be described later. In the form shown in FIG. 1, an example is shown in which the lower metal sheet 10 and the upper metal sheet 20 are both formed in a rectangular shape in a plan view, but the present invention is not limited to this. Here, the plan view is a state in which the vapor chamber 1 is viewed from a direction orthogonal to the heat receiving surface 10b that receives heat from the device D and the heat radiating surface 20b that releases the received heat. It corresponds to the state seen from above (see FIG. 1) or the state seen from below.

When the vapor chamber 1 is installed in the mobile terminal, the vertical relationship between the lower metal sheet 10 and the upper metal sheet 20 may be broken depending on the posture of the mobile terminal. However, in the present embodiment, the metal sheet on the liquid phase side that receives heat from the device D is referred to as the lower metal sheet 10, and the metal sheet on the gas phase side that releases the received heat is referred to as the upper metal sheet 20. A state in which the lower metal sheet 10 is arranged on the lower side and the upper metal sheet 20 is arranged on the upper side will be described.

As shown in FIGS. 1 to 4, the lower metal sheet 10 has an upper surface 10a (first surface, a surface on the side of the upper metal sheet 20) and a heat receiving surface 10b (third surface) provided on the side opposite to the upper surface 10a. Two surfaces), an outer surface 10c, an evaporation portion 11 on which the hydraulic fluid 2 evaporates to generate vapor, and a lower flow path recess 12 provided on the upper surface 10a and formed in a rectangular shape in a plan view. Have. Of these, the lower flow path recess 12 constitutes a part of the sealed space 3 described above, and mainly evaporates the working liquid 2 (see FIGS. 2 to 4) condensed from the vapor generated by the evaporation unit 11. It is configured to be transported to section 11. The evaporation portion 11 is a portion where the working liquid 2 in the sealed space 3 evaporates by receiving heat from the device D attached to the heat receiving surface 10b of the lower metal sheet 10. Therefore, the term evaporating unit 11 is used not only as a concept limited to a portion overlapping the device D, but also as a concept including a portion where the working fluid 2 can evaporate even if it does not overlap the device D. Here, the evaporation portion 11 can be provided at an arbitrary location on the lower metal sheet 10, but FIG. 1 shows an example in which the evaporation portion 11 is provided at the central portion of the lower metal sheet 10. In this case, it is possible to prevent the posture of the mobile terminal on which the vapor chamber 1 is installed from affecting the stabilization of the operation of the vapor chamber 1.

In the present embodiment, as shown in FIGS. 1 to 4, inside the lower flow path recess 12 of the lower metal sheet 10, the lower flow path recess 12 is above the bottom surface 12a (described later) (perpendicular to the bottom surface 12a). A plurality of lower flow path protrusions 13 are provided so as to project in the above direction. In the present embodiment, an example in which the lower flow path protrusion 13 is formed as a columnar boss is shown, and includes an upper surface 13a and a side surface 13b. Further, the lower flow path protrusions 13 are arranged at equal intervals along the longitudinal direction (left-right direction in FIG. 1) of the vapor chamber 1. Further, the lower flow path protrusion portion 13 is also arranged along the transverse direction of the vapor chamber 1 (horizontal direction orthogonal to the longitudinal direction, vertical direction in FIG. 1). A bottom surface 12a of the lower flow path recess 12 is formed around the lower flow path protrusion 13 arranged in this way. In this way, the hydraulic fluid 2 is configured to flow around the lower flow path protrusion 13, and it is possible to prevent the flow of the hydraulic fluid 2 from being obstructed. Further, the lower flow path protrusion 13 is arranged so as to overlap the corresponding upper flow path protrusion 22 (described later) of the upper metal sheet 20 in a plan view, thereby improving the mechanical strength of the vapor chamber 1. ing. The bottom surface 12a and the side surface 13b of the lower flow path protrusion 13 form the space-defining surface 3a of the sealed space 3 described above.

As shown in FIGS. 2 to 4, a wick W is provided in the lower flow path recess 12. Here, the wick is a member formed of, for example, a metal mesh in which a copper wire is pressed into an irregular shape or a porous sintered body, and exerts a capillary action. The wick W is configured to exert a capillary action to give a propulsive force toward the evaporation portion 11 to the hydraulic fluid 2 in the lower flow path recess 12. In this way, the hydraulic fluid 2 in the lower flow path recess 12 condensed from the vapor is smoothly transported toward the evaporation portion 11. As shown in FIGS. 2 to 4, the wick W may be provided in the entire region of the bottom surface 12a of the lower flow path recess 12. The wick W provided in the evaporation portion 11 of the bottom surface 12a can increase the heat exchange area between the liquid hydraulic fluid 2 and the heat received from the device D, and can contribute to improving the thermal efficiency. On the other hand, the wick W provided around the evaporation unit 11 on the bottom surface 12a can contribute to effectively transporting the liquid working liquid 2 to the evaporation unit 11. The wick W is attached so as to be fitted in the region between the lower flow path protrusions 13 of the lower flow path recesses 12 to prevent the wick W from moving depending on the posture of the vapor chamber 1. ing. Further, the height of the wick W can be made arbitrary as long as the heat exchange area in the evaporation unit 11 can be increased and the flow rate of the hydraulic fluid 2 toward the evaporation unit 11 can be secured by the capillary action.

As shown in FIGS. 1 to 4, a lower peripheral wall 14 is provided on the peripheral edge of the lower metal sheet 10. The lower peripheral wall 14 is formed so as to surround the sealing space 3, particularly the lower flow path recess 12, and defines the sealing space 3. The lower peripheral wall 14 has an upper surface 14a that abuts on the lower surface 23a of the upper peripheral wall 23, which will be described later. Further, as shown in FIG. 1, lower alignment holes 15 for positioning the lower metal sheet 10 and the upper metal sheet 20 are provided at the four corners of the lower peripheral wall 14 in a plan view.

In the present embodiment, the upper metal sheet 20 has the same structure as the lower metal sheet 10 except that the roughened portion 30 is formed. That is, the vapor chamber 1 according to the present embodiment is configured to become the upper metal sheet 20 when the lower metal sheet 10 is turned upside down, except for the roughened portion 30. Therefore, when the roughened portion 30 is formed after joining the lower metal sheet 10 and the upper metal sheet 20, two metal sheets having the same structure as the lower metal sheet 10 are produced, and one of them is used. It can also be flipped upside down and joined to each other. The configuration of the upper metal sheet 20 will be described in more detail below.

As shown in FIGS. 1 to 4, the upper metal sheet 20 has a lower surface 20a (first surface, a surface on the side of the lower metal sheet 10) and a heat radiating surface 20b (third surface) provided on the side opposite to the lower surface 20a. It has two surfaces), an outer surface 20c, and an upper flow path recess 21 provided on the lower surface 20a. The upper flow path recess 21 constitutes a part of the sealed space 3, and is mainly configured to diffuse and cool the steam generated by the evaporation unit 11. More specifically, the steam in the upper flow path recess 21 diffuses in the direction away from the evaporation portion 11, and most of the steam is transported to the peripheral portion having a relatively low temperature.

In the present embodiment, as shown in FIG. 1, the ceiling surface 21a of the upper flow path recess 21 (upper flow when the upper metal sheet 20 is turned upside down) is inside the upper flow path recess 21 of the upper metal sheet 20. A plurality of upper flow path protrusions 22 projecting downward (in a direction perpendicular to the ceiling surface 21a) from (corresponding to the bottom surface of the road recess 21) are provided. In the present embodiment, an example in which the upper flow path protrusion 22 is formed as a columnar boss is shown, and includes a lower surface 22a and a side surface 22b. Further, the upper flow path protrusions 22 are arranged at equal intervals along the longitudinal direction of the vapor chamber 1. Further, the upper flow path protrusion 22 is arranged along the transverse direction of the vapor chamber 1. A ceiling surface 21a of the upper flow path recess 21 (a surface corresponding to the bottom surface 12a of the lower flow path recess 12) is formed around the upper flow path protrusion 22 arranged in this way. In this way, the vapor of the working liquid 2 is configured to flow around the upper flow path protrusion 22, and the flow of the vapor is suppressed from being obstructed. Further, the upper flow path protrusion 22 is arranged so as to overlap the corresponding lower flow path protrusion 13 of the lower metal sheet 10 in a plan view, thereby improving the mechanical strength of the vapor chamber 1. .. The ceiling surface 21a and the side surface 22b of the upper flow path protrusion 22 form the space-defining surface 3a of the sealed space 3 described above.

As shown in FIGS. 1 to 4, an upper peripheral wall 23 is provided on the peripheral edge of the upper metal sheet 20. The upper peripheral wall 23 is formed so as to surround the sealing space 3, particularly the upper flow path recess 21, and defines the sealing space 3. The upper peripheral wall 23 has a lower surface 23a that abuts on the upper surface 14a of the lower peripheral wall 14. Further, as shown in FIG. 1, upper alignment holes 24 for positioning the lower metal sheet 10 and the upper metal sheet 20 are provided at the four corners of the upper peripheral wall 23 in a plan view. That is, each upper alignment hole 24 is arranged so as to overlap each of the above-mentioned lower alignment holes 15 at the time of temporary fixing described later, and is configured to enable positioning of the lower metal sheet 10 and the upper metal sheet 20. ..

Such a lower metal sheet 10 and an upper metal sheet 20 are preferably diffusively bonded and permanently bonded to each other. More specifically, as shown in FIGS. 2 to 4, the upper surface 14a of the lower peripheral wall 14 of the lower metal sheet 10 and the lower surface 23a of the upper peripheral wall 23 of the upper metal sheet 20 are in contact with each other, and the lower surface 23a is in contact with each other. The side peripheral wall 14 and the upper peripheral wall 23 are joined to each other. As a result, a sealing space 3 in which the hydraulic fluid 2 is sealed is formed between the lower metal sheet 10 and the upper metal sheet 20. Further, the upper surface 13a of the lower flow path protrusion 13 of the lower metal sheet 10 and the lower surface 22a of the upper flow path protrusion 22 of the upper metal sheet 20 come into contact with each other and correspond to each lower flow path protrusion 13. The upper flow path protrusion 22 is joined to each other. This improves the mechanical strength of the vapor chamber 1. In particular, since the lower flow path protrusion 13 and the upper flow path protrusion 22 according to the present embodiment are arranged at equal intervals, the mechanical strength at each position of the vapor chamber 1 can be equalized. The lower metal sheet 10 and the upper metal sheet 20 may be joined by another method such as brazing as long as they can be permanently joined instead of diffusion joining.

Further, as shown in FIGS. 1 and 3, the vapor chamber 1 is further provided with an injection portion 4 for injecting the hydraulic fluid 2 into the sealed space 3 at one end of the pair of ends in the longitudinal direction. There is. The injection portion 4 has a lower injection protrusion 16 projecting from the end surface of the lower metal sheet 10 and an upper injection protrusion 25 projecting from the end surface of the upper metal sheet 20. Of these, the lower injection flow path recess 17 is formed on the upper surface of the lower injection protrusion 16, and the upper injection flow path recess 26 is formed on the lower surface of the upper injection protrusion 25. The lower injection flow path recess 17 communicates with the lower flow path recess 12, and the upper injection flow path recess 26 communicates with the upper flow path recess 21. The lower injection flow path recess 17 and the upper injection flow path recess 26 form an injection flow path for the hydraulic fluid 2 when the lower metal sheet 10 and the upper metal sheet 20 are joined. The hydraulic fluid 2 is injected into the sealed space 3 through the injection flow path. In the present embodiment, an example is shown in which the injection portion 4 is provided at one end of a pair of ends in the longitudinal direction of the vapor chamber 1, but the present invention is not limited to this. do not have.

Next, the roughened portion 30 according to the present embodiment will be described in more detail. In this embodiment, an example in which the roughened portion 30 is formed by half etching will be described.

The roughened portion 30 is a space-defining surface 3a of the sealed space 3 (that is, a bottom surface 12a of the lower flow path recess 12, a side surface 13b of the lower flow path protrusion 13, a ceiling surface 21a of the upper flow path recess 21, and the surface surface 21a. It has a surface roughness larger than the surface roughness of the side surface 22b) of the upper flow path protrusion 22). In the present embodiment, as shown in FIGS. 2 to 4, the roughened portion 30 is provided on the entire heat radiating surface 20b of the upper metal sheet 20.

The surface roughness of the roughened portion 30 is preferably Ra of 0.1 μm to 5.0 μm when expressed by the arithmetic mean roughness defined in JIS B0601-2001, but it is still rough. The surface roughness of the surfaced portion 30 may be less than 0.1 μm or more than 5.0 μm. On the other hand, the space-defining surface 3a of the sealed space 3 is formed by etching as described later, and has a surface roughness of Ra of 0.01 μm to 0.07 μm. Therefore, by keeping the surface roughness of the roughened portion 30 within the above-mentioned numerical range, the surface roughness of the roughened portion 30 can be made larger than the surface roughness of the spatially defined surface 3a. For the measurement of Ra, for example, it is preferable to use a light wave interference type surface roughness meter (ZYGO, New view 5032), a laser microscope (Keyence, VK-9500), or the like.

In the present embodiment, as shown in FIGS. 2 to 4, the roughened surface portion 30 is provided between the plurality of roughened convex portions 31 that are spaced apart from each other and the roughened convex portions 31 that are adjacent to each other. It has a roughened concave portion 32 and the surface roughened recess 32. Of these, the roughened recess 32 is formed by half etching, which will be described later. The roughened convex portion 31 and the roughened concave portion 32 are formed finely so that the roughened portion 30 has a desired surface roughness.

The shape and arrangement of the roughened convex portion 31 are arbitrary as long as the surface roughness of the heat radiating surface 20b of the upper metal sheet 20 can be made to a desired surface roughness. For example, as shown in FIG. 5A, the roughened convex portions 31 may be formed in a circular shape in a plan view and may be arranged in a grid pattern. In this case, the diameter of the roughened convex portion 31 in a plan view is 10 μm to 2000 μm, the arrangement pitch of the roughened convex portion 31 is 20 μm to 4000 μm, and the height of the roughened convex portion 31 is 0.2 μm to 10 μm. Therefore, the surface roughness of the roughened portion 30 can be kept within the above-mentioned numerical range. Any value can be set for the diameter and the arrangement pitch of the roughened convex portion 31. In addition, depending on the desired surface roughness, the numerical value of the height of the roughened convex portion 31 may be a numerical value outside the above-mentioned numerical range. Alternatively, as shown in FIG. 5B, the roughened convex portions 31 may be formed in a rectangular shape in a plan view and arranged in a grid pattern. Further, as shown in FIG. 5 (c), the roughened convex portions 31 may be formed in a circular shape in a plan view and may be arranged in a staggered pattern, and further, as shown in FIG. 5 (d). The roughened convex portions 31 may be formed in a hexagonal shape in a plan view and may be arranged in a staggered shape (or a honeycomb shape).

The cross-sectional shape of the roughened concave portion 32 is arbitrary as long as the surface roughness of the heat radiating surface 20b can be made to a desired surface roughness. For example, as shown in FIG. 6A, the cross section of the roughened recess 32 may be formed in a rectangular shape. Alternatively, as shown in FIG. 6 (b), the cross section of the roughened recess 32 may be formed in a semicircular shape, and as shown in FIG. 6 (c), it may be triangular or V-shaped. It may be formed. Further, the cross section of the roughened concave portion 32 may be formed in an inverted tapered shape. For example, in FIG. 6D, the roughened concave portion 32 is provided on the concave portion opening 33 and the bottom side (lower side in FIG. 6D) of the roughened concave portion 32 than the concave portion opening 33. It has a large portion 34 and. The recess opening 33 is an opening at a position corresponding to the heat radiating surface 20b in the roughened recess 32. The large portion 34 is arranged on the bottom side (lower side) in FIG. 6D with respect to the concave opening 33. When the width of the concave opening 33 is w1 and the width of the large portion 34 is w2, w1 <w2. The cross section of the roughened recess 32 shown in FIG. 6D is formed in an arc shape (C shape, octopus trap shape). As another example of the inverted tapered shape, as shown in FIG. 6E, the cross section of the roughened concave portion 32 may be formed in a trapezoidal shape. When the spray etching method is adopted, the cross-sectional shape of the roughened concave portion 32 may be changed by controlling the spray pressure of the etching solution or changing the pattern shape of the second resist film 40 described later. Can be obtained by When the roughened concave portion 32 is formed in an inverted tapered shape as shown in FIGS. 6 (d) and 6 (e), the peripheral length of the roughened concave portion 32 may be increased in the cross-sectional view of the roughened concave portion 32. It can increase the surface area.

By the way, the material used for the lower metal sheet 10 and the upper metal sheet 20 is not particularly limited as long as it is a material having good thermal conductivity. For example, the lower metal sheet 10 and the upper metal sheet 20 are made of copper. Alternatively, it is preferably formed of a copper alloy. As a result, the thermal conductivity of the lower metal sheet 10 and the upper metal sheet 20 can be increased. Therefore, the heat transport efficiency of the vapor chamber 1 can be improved. The thickness T0 of the vapor chamber 1 is 0.1 mm to 1.0 mm. FIG. 4 shows a case where the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 are equal, but the present invention is not limited to this, and the thickness T1 of the lower metal sheet 10 and the upper side are not limited to this. The thickness T2 of the metal sheet 20 does not have to be equal.

Next, the operation of the present embodiment having such a configuration will be described. Here, first, the manufacturing method of the vapor chamber 1 will be described with reference to FIGS. 7 to 16, but the description of the half-etching step of the lower metal sheet 10 will be simplified. In addition, in FIGS. 7 to 9 and 14 to 16, the cross section similar to the cross section of FIG. 4 is shown.

First, as a preparation step of the upper metal sheet 20, as shown in FIG. 7, a flat metal material sheet M is prepared.

Subsequently, as a defining surface forming step (first half etching step) of the upper metal sheet 20, as shown in FIG. 8, the metal material sheet M is half-etched to form the space defining surface 3a of the sealed space 3. .. In this way, the upper metal sheet 20 having the upper flow path recess 21 forming a part of the sealed space 3 is formed.

In the defining surface forming step, first, a first resist film (not shown) is formed on the lower surface Ma of the metal material sheet M in a pattern corresponding to the plurality of upper flow path protrusions 22 and the upper peripheral wall 23 by photolithography technology. Will be done. Subsequently, as the first half etching step, the lower surface Ma of the metal material sheet M is half-etched. As a result, the portion of the lower surface Ma of the metal material sheet M corresponding to the opening (not shown) of the first resist film is half-etched to form the space defining surface 3a of the sealed space 3, as shown in FIG. The upper flow path recess 21, the upper flow path protrusion 22, and the upper peripheral wall 23 are formed. At this time, the upper injection flow path recess 26 shown in FIGS. 1 and 3 is also formed at the same time, and the metal material sheet M is etched from the lower surface Ma and the upper surface to form the outer surface 20c to form a predetermined outer contour shape. Is obtained. After the first half etching step, the first resist film is removed. The half etching means etching for forming a recess that does not penetrate the material. Therefore, the depth of the recess formed by half etching is not limited to half the thickness of the upper metal sheet 20. As the etching solution, for example, an iron chloride-based etching solution such as a ferric chloride aqueous solution or a copper chloride-based etching solution such as a copper chloride aqueous solution can be used.

After the defining surface forming step, as a roughening step, as shown in FIG. 9, a roughened portion 30 is formed on the heat radiating surface 20b of the upper metal sheet 20. Here, the roughened portion 30 is formed by half etching.

In the roughening step, first, as shown in FIG. 10, a second resist film 40 is formed on the heat radiating surface 20b of the upper metal sheet 20. At this time, the second resist film 40 is formed on the entire surface including the lower surface 20a of the upper metal sheet 20. An electrodeposited resist material that can be adhered by an electric field can be preferably used for the second resist film 40, but other materials such as a liquid resist material may also be used.

Subsequently, as shown in FIG. 11, the second resist film 40 is patterned. That is, the second resist film 40 is formed in a pattern corresponding to the plurality of roughened recesses 32 by the photolithography technique, and the resist opening 41 is formed.

Subsequently, as shown in FIG. 12, the heat radiating surface 20b of the upper metal sheet 20 is half-etched as the second half-etching step. That is, the heat radiating surface 20b is half-etched from the resist opening 41 of the second resist film 40 to form the roughened portion 30. As a result, the portion of the heat radiating surface 20b corresponding to the resist opening 41 of the second resist film 40 is half-etched, and a roughened concave portion 32 is formed on the heat radiating surface 20b. The non-half-etched portion adjacent to the roughened concave portion 32 becomes the roughened convex portion 31. The etching solution used in the second half etching step is not particularly limited, but may be the same as the etching solution used in the first half etching step.

After that, as shown in FIG. 13, the second resist film 40 is removed. In this way, the upper metal sheet 20 on which the roughened portion 30 as shown in FIG. 9 is formed can be obtained.

On the other hand, similarly to the upper metal sheet 20, the metal material sheet (not shown) for the lower metal sheet 10 is half-etched from the upper surface, and the lower flow path recess 12, the lower flow path protrusion 13 and the lower A side peripheral wall 14 is formed. Then, the wick W is inserted and fitted between the lower flow path protrusions 13 of the lower flow path recess 12. In this way, the lower metal sheet 10 described above is obtained.

Next, as a temporary fixing step, as shown in FIG. 14, the lower metal sheet 10 having the lower flow path recess 12 and the upper metal sheet 20 having the upper flow path recess 21 are temporarily fixed. In this case, first, the lower metal sheet 10 and the upper metal are used by using the lower alignment hole 15 (see FIG. 1) of the lower metal sheet 10 and the upper alignment hole 24 (see FIG. 1) of the upper metal sheet 20. The sheet 20 is positioned. Subsequently, 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 are fixed by resistance welding to the lower metal sheet 10 and the upper metal sheet 20. You may. In this case, as shown in FIG. 14, it is preferable to perform spot resistance welding using the electrode rod 42. Laser welding may be performed instead of resistance welding. In this way, the lower metal sheet 10 and the upper metal sheet 20 are fixed in a positioned state.

After the temporary fixing step, as a joining step, as shown in FIG. 15, the lower metal sheet 10 and the upper metal sheet 20 are permanently joined by diffusion joining. Diffusion bonding means that 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 reduced pressure atmosphere, the metal sheets 10 and 20 are pressed and heated in the direction of close contact, and atoms generated on the bonded surface are formed. It is a method of joining using the diffusion of. Diffusion bonding heats the materials of the lower metal sheet 10 and the upper metal sheet 20 to a temperature close to the melting point, but since it is lower than the melting point, it is possible to prevent the metal sheets 10 and 20 from melting and deforming. More specifically, the upper surface 14a of the lower peripheral wall 14 of the lower metal sheet 10 and the lower surface 23a of the upper peripheral wall 23 of the upper metal sheet 20 are diffusively joined as a joining surface. As a result, the lower peripheral wall 14 and the upper peripheral wall 23 form a sealing space 3 between the lower metal sheet 10 and the upper metal sheet 20. Further, the lower injection flow path recess 17 (see FIGS. 1 and 3) and the upper injection flow path recess 26 (see FIGS. 1 and 3) form an injection flow path for the hydraulic fluid 2 communicating with the sealed space 3. Will be done. Further, the upper surface 13a of the lower flow path protrusion 13 of the lower metal sheet 10 and the lower surface 22a of the upper flow path protrusion 22 of the upper metal sheet 20 are diffusively joined as joint surfaces to form the vapor chamber 1. Mechanical strength is improved.

After the joining step, as a sealing step, the working liquid 2 is injected into the sealed space 3 from the injection section 4 (see FIGS. 1 and 3) as shown in FIG. At this time, first, the sealed space 3 is evacuated and depressurized, and then the working fluid 2 is injected into the sealed space 3. At the time of injection, the working fluid 2 passes through the injection flow path formed by the lower injection flow path recess 17 and the upper injection flow path recess 26.

After injecting the working fluid 2, the above-mentioned injection flow path is sealed. For example, it is preferable to irradiate the injection unit 4 with a laser to partially melt the injection unit 4 to seal the injection flow path. As a result, the communication between the sealed space 3 and the outside air is cut off, and the hydraulic fluid 2 is sealed in the sealed space 3. In this way, the hydraulic fluid 2 in the sealed space 3 is prevented from leaking to the outside.

As described above, the vapor chamber 1 according to the present embodiment is obtained.

The vapor chamber 1 obtained as described above is installed in a housing of a mobile terminal or the like, and a device D such as a CPU, which is an object to be cooled, is attached to a heat receiving surface 10b of the lower metal sheet 10. .. In this case, the heat radiating surface 20b of the upper metal sheet 20 is housed in the housing without coming into contact with other members. The periphery of the heat radiating surface 20b is covered with the air inside the housing. An insulating sheet for avoiding contact with other electronic circuit components may be attached to the heat radiating surface 20b.

Next, a method of operating the vapor chamber 1, that is, a method of cooling the device D will be described.

When the lower metal sheet 10 is arranged vertically below and the upper metal sheet 20 is arranged vertically above, most of the hydraulic fluid 2 sealed in the sealed space 3 is affected by gravity and is located on the lower side. It stays in the lower flow path recess 12 of the metal sheet 10.

When the device D generates heat in this state, the working liquid 2 existing in the evaporation portion 11 of the lower flow path recess 12 receives heat from the device D. The received heat is absorbed as latent heat, the working liquid 2 evaporates (vaporizes), and the vapor of the working liquid 2 is generated. Most of the generated steam rises in the sealed space 3 and diffuses into the upper flow path recess 21. A part of the generated steam also diffuses in the lower flow path recess 12 of the lower metal sheet 10. The steam in the upper flow path recess 21 and the lower flow path recess 12 is separated from the evaporation portion 11, and most of the steam is transported to the peripheral portion where the temperature is relatively low (see the solid line arrow in FIG. 3). The diffused steam dissipates heat to the lower metal sheet 10 and the upper metal sheet 20 of the vapor chamber 1 and is cooled.

The heat received from the steam by the lower metal sheet 10 and the upper metal sheet 20 is transferred to the surrounding air from the heat radiating surface 20b of the upper metal sheet 20 and released. At this time, the heat radiating surface 20b is provided with a roughened portion 30 (roughened convex portion 31 and roughened concave portion 32) having a surface roughness larger than the surface roughness of the space defining surface 3a defining the sealed space 3. It is formed. As a result, in the roughened portion 30, the contact area between the heat radiating surface 20b and the surrounding air is increased, and the thermal resistance between the heat radiating surface 20b and the surrounding air is reduced. As a result, heat is efficiently released from the heat radiating surface 20b. In other words, the lower metal sheet 10 and the upper metal sheet 20 are efficiently cooled by the surrounding air, whereby the hydraulic fluid 2 in the lower flow path recess 12 and the upper flow path recess 21 in the sealed space 3 The steam can be cooled efficiently. Therefore, the condensation rate of the vapor in the sealed space 3 can be increased, and the phase change of the working fluid 2 can be promoted.

By radiating heat to the lower metal sheet 10 and the upper metal sheet 20, the steam loses the latent heat absorbed in the evaporation unit 11 and condenses. The hydraulic fluid 2 that has become liquid in the upper flow path recess 21 descends in the upper flow path recess 21 and reaches the lower flow path recess 12. Since the working liquid 2 continues to evaporate in the evaporation part 11, the working liquid 2 in the lower flow path recess 12 other than the evaporation part 11 is transported toward the evaporation part 11 (broken line arrow in FIG. 3). reference). At this time, the lower flow path recess 12 is provided with a wick W capable of exerting a capillary action. Therefore, due to the capillary action of the wick W, the working liquid 2 obtains a propulsive force toward the evaporation unit 11 and is smoothly transported toward the evaporation unit 11.

The working liquid 2 that has reached the evaporation unit 11 receives heat again from the device D and evaporates. In this way, the working fluid 2 recirculates in the vapor chamber 1 while repeating phase change, that is, evaporation and condensation, and transfers and releases the heat of the device D. As a result, the device D is cooled.

As described above, according to the present embodiment, the roughened portion 30 is provided on the heat radiating surface 20b of the upper metal sheet 20, and the roughened portion 30 is based on the surface roughness of the space defining surface 3a defining the sealed space 3. Also has a large surface roughness. As a result, in the roughened portion 30, the contact area between the heat radiating surface 20b and the air around the heat radiating surface 20b can be increased, and the thermal resistance between the heat radiating surface 20b and the surrounding air is reduced. be able to. Therefore, the vapor of the hydraulic fluid 2 in the sealed space 3 can be efficiently cooled and condensed. As a result, the heat transport efficiency can be improved.

Further, according to the present embodiment, the roughened portion 30 has a plurality of roughened convex portions 31 and a roughened concave portion 32 provided between the roughened convex portions 31 adjacent to each other. Have. Thereby, the plane size (diameter in the plan view), the arrangement pitch, and the half etching depth (height) of the roughened convex portion 31 can be arbitrarily designed. Therefore, the roughened portion 30 can have a desired contact area, and the thermal resistance of the roughened portion 30 can be controlled.

In the present embodiment described above, an example in which the roughened portion 30 is provided on the entire heat radiating surface 20b of the upper metal sheet 20 has been described. However, the present invention is not limited to this, and the roughened portion 30 may be formed on a part of the heat radiating surface 20b. Even in this case, in the roughened portion 30, the thermal resistance between the heat radiating surface 20b and the surrounding air can be reduced, and the heat transport efficiency can be improved.

Further, in the above-described embodiment, the example in which the roughened portion 30 is provided on the heat radiating surface 20b of the upper metal sheet 20 has been described. However, the present invention is not limited to this, and as shown in FIG. 17, the roughened portion 30 may be provided on at least a part of the heat receiving surface 10b of the lower metal sheet 10. FIG. 17 shows an example in which the roughened portion 30 is provided on the entire heat receiving surface 10b. The roughened portion 30 can be formed on the heat receiving surface 10b by the same method as the method for forming the roughened portion 30 on the heat radiating surface 20b of the upper metal sheet 20.

When the roughened portion 30 is provided on the portion of the heat receiving surface 10b to which the device D is attached, the thermal resistance between the device D and the heat receiving surface 10b can be reduced. In particular, when a soft heat conductive sheet (not shown) is interposed between the heat receiving surface 10b and the device D, the heat conductive sheet is placed in the roughened concave portion 32 of the roughened portion 30. Since it can penetrate, the contact area between the heat receiving surface 10b and the heat conductive sheet can be increased. As a result, the thermal resistance between the heat receiving surface 10b and the device D can be reduced, and the heat transport efficiency can be improved. Instead of the heat conductive sheet, a semi-solid member such as grease for easily conducting heat may be interposed between the heat receiving surface 10b and the device D.

When the roughened portion 30 is provided on a portion of the heat receiving surface 10b other than the portion to which the device D is attached, the thermal resistance between the lower metal sheet 10 and the surrounding air can be reduced. It is possible to further cool and condense the vapor of the hydraulic fluid 2 in the sealed space 3 to improve the heat transport efficiency.

Further, in the above-described embodiment, an example has been described in which the heat radiating surface 20b provided with the roughened portion 30 is covered with air without coming into contact with other members. However, it is not limited to this. For example, a housing member (not shown) forming a part of a housing of a mobile terminal or the like may be arranged on the heat radiating surface 20b. In this case, it is preferable that a soft heat conductive sheet (not shown) is interposed between the heat radiating surface 20b and the housing member. Since such a heat conductive sheet can enter the roughened concave portion 32 of the roughened portion 30, the contact area between the heat radiating surface 20b and the heat conductive sheet can be increased. As a result, the thermal resistance between the heat radiating surface 20b and the heat conductive sheet, that is, the thermal resistance between the heat radiating surface 20b and the housing member can be reduced, and the heat transport efficiency can be improved. Instead of the heat conductive sheet, a semi-solid member such as grease for easily conducting heat may be interposed between the heat radiating surface 20b and the housing member.

Further, in the above-described embodiment, the roughening step for forming the roughened portion 30 is a demarcating surface forming step for forming the space demarcating surface 3a of the sealed space 3, the lower metal sheet 10 and the upper metal. An example performed between the joining step of joining the sheet 20 (more specifically, between the demarcation surface forming step and the temporary joining step) has been described. However, the present invention is not limited to this, and the roughening step may be performed after the encapsulation step of encapsulating the working liquid 2. That is, after the hydraulic fluid 2 is sealed as shown in FIG. 16, the roughened portion 30 may be formed on the heat radiating surface 20b of the upper metal sheet 20 by etching. Further, the roughening step may be performed at the same time as the defining surface forming step. In this case, it is preferable that the width of the resist opening 41 shown in FIGS. 11 and 12 is smaller than the width of the roughened recess 32. As a result, the amount of the etching solution that enters the resist opening 41 is reduced, and the etching rate of the portion of the heat radiating surface 20b corresponding to the resist opening 41 is reduced. Therefore, the depth of the roughened recess 32 formed by the resist opening 41 can be made shallow while forming the upper flow path recess 21 having a desired depth. When the roughening step and the defining surface forming step are performed at the same time as described above, the number of half etching steps can be reduced and the manufacturing efficiency can be improved.

Further, in the present embodiment described above, an example in which the roughened portion 30 is formed by etching has been described. However, the present invention is not limited to this, and the roughened portion 30 may be formed by cutting by machining.

(Second Embodiment)
Next, a method for manufacturing the vapor chamber, the metal sheet for the vapor chamber, and the vapor chamber according to the second embodiment of the present invention will be described with reference to FIG.

The second embodiment shown in FIG. 18 is mainly different in that the roughened portion is roughened by the grain interface of the crystal of the material, and other configurations are shown in FIGS. 1 to 17. It is substantially the same as the first embodiment. In FIG. 18, the same parts as those in the first embodiment shown in FIGS. 1 to 17 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 18, in the present embodiment, the roughened portion 30 is provided on the entire heat radiating surface 20b of the upper metal sheet 20. Further, the roughened portion 30 is formed by half etching, and is roughened by the grain interface 51 of the crystal 50 of the material constituting the upper metal sheet 20. The surface roughness (Ra) of the roughened portion 30 according to the present embodiment is preferably 0.20 μm to 1.20 μm.

Further, in the present embodiment, the roughened portion 30 is also formed on the entire heat receiving surface 10b of the lower metal sheet 10 and the entire peripheral outer surface 5. That is, the roughened portion 30 is formed on the heat radiating surface 20b and the outer surface 20c of the upper metal sheet 20 and the heat receiving surface 10b and the outer surface 10c of the lower metal sheet 10. In this way, the roughened portion 30 is formed over the entire vapor chamber 1. However, the roughened portion 30 may not be formed in the injection portion 4 of the vapor chamber 1.

In the present embodiment, it is preferable that the roughening step for forming the roughened portion 30 is performed after the sealing step for filling the working liquid 2. That is, as shown in FIG. 16, after the hydraulic fluid 2 is sealed, the roughened portion 30 is formed on the heat receiving surface 10b and the outer surface 10c of the lower metal sheet 10 and the heat radiating surface 20b and the outer surface 20c of the upper metal sheet 20. May be formed.

The etching solution for forming the roughened portion 30 according to the present embodiment preferably has a small erosion effect. That is, it is preferable that the etching solution used in the roughening step for forming the roughened portion 30 has a smaller erosion effect than the etching solution used in the defining surface forming step for forming the space defining surface 3a of the sealed space 3. .. As a result, it is possible to prevent the material from being eroded without being involved in the grain interface 51 of the crystal 50, and to form the roughened portion 30 having a shape along the grain interface 51. As such an etching solution, it is preferable that the etching solution is a formic acid-based etching solution having a smaller erosion effect than the etching solution used in the first half etching step of the demarcation surface forming step. It is preferable to use the EMR series manufactured by Gas Chemical Company.

As described above, according to the present embodiment, the roughened portion 30 provided on the heat receiving surface 10b of the lower metal sheet 10 is formed by the grain interface 51 of the crystals 50 of the material constituting the lower metal sheet 10. The roughened portion 30 provided on the heat radiating surface 20b of the upper metal sheet 20 is formed by the grain interface 51 of the crystals 50 of the materials constituting the upper metal sheet 20. As a result, the heat receiving surface 10b and the heat radiating surface 20b can be roughened by etching, so that the heat receiving surface 10b and the heat radiating surface 20b can be easily roughened.

Further, according to the present embodiment, the roughened portion 30 is provided not only on the heat radiating surface 20b of the upper metal sheet 20 but also on the heat receiving surface 10b of the lower metal sheet 10. As a result, the thermal resistance between the device D and the heat receiving surface 10b can be reduced by the roughened portion 30 provided in the portion of the heat receiving surface 10b to which the device D is attached. Therefore, the heat transport efficiency can be improved. Further, the thermal resistance between the lower metal sheet 10 and the surrounding air can be reduced by the roughened portion 30 provided on the portion of the heat receiving surface 10b other than the portion to which the device D is attached. Therefore, the vapor of the hydraulic fluid 2 in the sealed space 3 can be further cooled and condensed, and the heat transport efficiency can be improved.

Further, according to the present embodiment, the roughened portion 30 is also provided on the outer peripheral surface 5 of the vapor chamber 1. This makes it possible to reduce the thermal resistance between the peripheral outer surface 5 and the surrounding air. Therefore, the vapor of the hydraulic fluid 2 in the sealed space 3 can be further cooled and condensed, and the heat transport efficiency can be further improved.

Further, according to the present embodiment, the roughening step is performed after the encapsulation step. As a result, it is possible to prevent the grain interface 51 from receiving heat during the joining process, and it is possible to avoid losing the roughening due to the grain interface 51 receiving heat.

In the above-described embodiment, the roughened portion 30 is formed on the heat receiving surface 10b of the lower metal sheet 10, the heat radiating surface 20b of the upper metal sheet 20, and the peripheral outer surface 5 of the vapor chamber 1. An example has been described. However, the present invention is not limited to this, and the roughened portion 30 may not be formed on the heat receiving surface 10b. Alternatively, the roughened portion 30 may not be formed on the outer peripheral surface 5.

(Third Embodiment)
Next, with reference to FIG. 19, a method for manufacturing a vapor chamber, a metal sheet for a vapor chamber, and a vapor chamber according to a third embodiment of the present invention will be described.

The third embodiment shown in FIG. 19 is mainly different in that the roughened portion is roughened by a plurality of electrodeposited objects, and the other configurations are the first shown in FIGS. 1 to 17. It is substantially the same as the embodiment of. In FIG. 19, the same parts as those in the first embodiment shown in FIGS. 1 to 17 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 19, in the present embodiment, the roughened portion 30 is provided on the entire heat radiating surface 20b of the upper metal sheet 20. Further, the roughened portion 30 is formed by electroplating, and is roughened by a plurality of hump-shaped electrodeposits 52. The surface roughness (Ra) of the roughened portion 30 according to the present embodiment is preferably 0.15 μm to 0.30 μm.

Further, in the present embodiment, the roughened portion 30 is also formed on the entire heat receiving surface 10b of the lower metal sheet 10 and the entire peripheral outer surface 5. That is, the roughened portion 30 is formed on the heat radiating surface 20b and the outer surface 20c of the upper metal sheet 20 and the heat receiving surface 10b and the outer surface 10c of the lower metal sheet 10. In this way, the roughened portion 30 is formed over the entire vapor chamber 1. However, the roughened portion 30 may not be formed in the injection portion 4 of the vapor chamber 1.

In the present embodiment, it is preferable that the roughening step for forming the roughened portion 30 is performed after the sealing step for filling the working liquid 2. That is, after the hydraulic fluid 2 is sealed as shown in FIG. 16, roughened portions are formed on the heat receiving surface 10b and the outer surface 10c of the lower metal sheet 10 and the heat radiating surface 20b and the outer surface 20c of the upper metal sheet 20. 30 may be formed.

The hump-shaped electrodeposited object 52 constituting the roughened portion 30 according to the present embodiment can be formed by electroplating called hump plating (also referred to as burnt plating). The formed electrodeposited object 52 becomes like a rounded protrusion. The electrodeposited material 52 is preferably formed of the same material as the material of the lower metal sheet 10 (for example, pure copper). In this case, the plating solution is Microposit manufactured by Roam & Haas, or Okuno Pharmaceutical Industry Co., Ltd. It is preferable to use a top rutina made of.

The electrodeposited object 52 of the roughened portion 30 according to the present embodiment may be formed in a needle shape. In this case, the surface roughness (Ra) of the roughened portion 30 is preferably 0.10 μm to 1.0 μm. When forming a needle-shaped electrodeposit, the electrodeposition conditions and the composition of the chemical solution additive may be adjusted.

As described above, according to the present embodiment, the roughened portion 30 provided on the heat receiving surface 10b of the lower metal sheet 10 is formed by the plurality of electrodeposited objects 52, and is formed on the heat radiating surface 20b of the upper metal sheet 20. The roughened portion 30 provided is formed by a plurality of electrodeposited objects 52. As a result, the heat receiving surface 10b and the heat radiating surface 20b can be easily roughened. Further, since the heat receiving surface 10b and the heat radiating surface 20b can be roughened by plating, the material of the electrodeposited object 52 can be changed by changing the type of plating solution.

Further, according to the present embodiment, the roughened portion 30 is provided not only on the heat radiating surface 20b of the upper metal sheet 20 but also on the heat receiving surface 10b of the lower metal sheet 10. As a result, the thermal resistance between the device D and the heat receiving surface 10b can be reduced by the roughened portion 30 provided in the portion of the heat receiving surface 10b to which the device D is attached. Therefore, the heat transport efficiency can be improved. Further, the thermal resistance between the lower metal sheet 10 and the surrounding air can be reduced by the roughened portion 30 provided on the portion of the heat receiving surface 10b other than the portion to which the device D is attached. Therefore, the vapor of the hydraulic fluid 2 in the sealed space 3 can be further cooled and condensed, and the heat transport efficiency can be improved.

Further, according to the present embodiment, the roughened portion 30 is also provided on the outer peripheral surface 5 of the vapor chamber 1. This makes it possible to reduce the thermal resistance between the peripheral outer surface 5 and the surrounding air. Therefore, the vapor of the hydraulic fluid 2 in the sealed space 3 can be further cooled and condensed, and the heat transport efficiency can be further improved.

Further, according to the present embodiment, the roughening step is performed after the encapsulation step. As a result, it is possible to prevent the electrodeposited object 52 from being melted by the heat during the joining process, and it is possible to prevent the electrodeposited object 52 from losing its roughening due to receiving heat.

In the above-described embodiment, the roughened portion 30 is formed on the heat receiving surface 10b of the lower metal sheet 10, the heat radiating surface 20b of the upper metal sheet 20, and the peripheral outer surface 5 of the vapor chamber 1. An example has been described. However, the present invention is not limited to this, and the roughened portion 30 may not be formed on the heat receiving surface 10b. Alternatively, the roughened portion 30 may not be formed on the outer peripheral surface 5.

The present invention is not limited to the above-described embodiment and modification as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in the above-described embodiments and modifications. Some components may be removed from all the components shown in the embodiments and modifications. In addition, components spanning different embodiments and variations may be combined as appropriate.

For example, in the above-described embodiment, the lower flow path protrusion 13 is provided as a boss in the lower flow path recess 12 of the lower metal sheet 10, and the upper flow path recess 21 of the upper metal sheet 20 is provided. An example in which the upper flow path protrusion 22 is provided as a boss has been described. However, the shape and configuration of the lower flow path protrusion 13 and the upper flow path protrusion 22 are not limited to this, and are arbitrary.

Further, in the above-described embodiment, the lower flow path recess 12 is formed as a part of the sealing space 3 on the upper surface 10a of the lower metal sheet 10, and is sealed on the lower surface 20a of the upper metal sheet 20. An example in which the upper flow path recess 21 is formed as a part of the space 3 has been described. However, the present invention is not limited to this, and the sealing space 3 may not be formed in any one of the lower metal sheet 10 and the upper metal sheet 20 as long as it is formed in the other.

Further, in the above-described embodiment, when the roughened portion 30 is formed in a needle shape, the method is not limited to the electrodeposition method. For example, when the lower metal sheet 10 and the upper metal sheet 20 are made of copper, the surface forming the roughened portion 30 is oxidized to precipitate copper oxide, whereby a needle-shaped electrodeposited material is formed. May be formed. Alternatively, the surface forming the roughened portion 30 may be reduced to precipitate cuprous oxide to form a needle-shaped electrodeposit. Also in this case, the surface roughness (Ra) of the roughened portion 30 can be set to 0.10 μm to 1.0 μm, similarly to the needle-shaped electrodeposited object 52 of the roughened portion 30 described above.

1 Vapor chamber 2 Working fluid 3 Sealed space 3a Space demarcation surface 5 Peripheral outer surface 30 Roughened part 31 Roughened convex part 32 Roughened concave part 33 Recessed opening 34 Large part 50 Crystal 51 Grain interface 52 Electrodeposition

Claims (22)

A vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The space demarcation surface that defines the sealed space and
The heat receiving surface that receives heat from the cooled device and
A heat radiating surface provided on the side opposite to the heat receiving surface side with respect to the sealed space,
Provided on at least a portion of Rutotomoni the heat receiving surface provided on at least a portion of the heat radiating surface, equipped with a roughened portion having a larger surface roughness than the surface roughness of the space defining surfaces, vapor chamber .. The vapor chamber according to claim 1 , wherein the roughened portion is roughened by the grain interface of the crystal of the material. The vapor chamber according to claim 1 , wherein the roughened portion is roughened by a plurality of electrodeposits. Further provided with an outer peripheral surface extending from the heat radiating surface to the heat receiving surface.
The vapor chamber according to claim 2 or 3 , wherein the roughened portion is also provided on the outer peripheral surface of the peripheral edge. A vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The space demarcation surface that defines the sealed space and
The heat receiving surface that receives heat from the cooled device and
A heat radiating surface provided on the side opposite to the heat receiving surface side with respect to the sealed space,
A roughened portion provided on at least a part of the heat radiating surface and having a surface roughness larger than the surface roughness of the space defining surface.
A peripheral outer surface extending from the heat radiating surface to the heat receiving surface is provided.
The roughened portion is roughened by the grain interface of the crystal of the material or by a plurality of electrodepositions.
The roughened portion is a vapor chamber that is also provided on the outer peripheral surface of the peripheral edge. A vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The space demarcation surface that defines the sealed space and
The heat receiving surface that receives heat from the cooled device and
A heat radiating surface provided on the side opposite to the heat receiving surface side with respect to the sealed space,
A roughened portion provided on at least a part of the heat radiating surface and having a surface roughness larger than the surface roughness of the space defining surface is provided.
The roughened portion has a plurality of spaced roughened convex portions.
A vapor chamber in which a plurality of roughened protrusions are arranged in two directions intersecting each other. The vapor chamber according to claim 6, wherein the roughened portion is also provided on at least a part of the heat receiving surface. A vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The space demarcation surface that defines the sealed space and
The heat receiving surface that receives heat from the cooled device and
A heat radiating surface provided on the side opposite to the heat receiving surface side with respect to the sealed space,
A roughened portion provided on at least a part of the heat radiating surface and having a surface roughness larger than the surface roughness of the space defining surface is provided.
The roughened portion is a vapor chamber that is roughened by the grain interface of the crystal of the material. The first metal sheet having the heat receiving surface and
A second metal sheet provided on the first metal sheet and having the heat radiating surface is further provided.
The vapor chamber according to any one of claims 1 to 8 , wherein the sealed space is formed between the first metal sheet and the second metal sheet. A metal sheet for a vapor chamber for a vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The first surface on which at least a part of the sealed space is formed, and
The space demarcation surface that defines the sealed space and
A second surface provided on the side opposite to the first surface,
Wherein provided on at least a portion of the second surface, Bei example and a roughened portion having a larger surface roughness than the surface roughness of the space defining surfaces,
The roughened portion has a plurality of spaced roughened convex portions.
A metal sheet for a vapor chamber in which a plurality of roughened convex portions are arranged in two directions intersecting each other. A method for manufacturing a vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
A preparatory step for preparing a first metal sheet to which the cooled device is attached and a second metal sheet, and
A demarcation surface forming step of forming a space demarcation surface that defines the sealed space on at least one of the first metal sheet and the second metal sheet.
The roughening process for forming the roughened portion and
A joining step of joining the first metal sheet and the second metal sheet to form the sealed space between the first metal sheet and the second metal sheet.
A sealing step of sealing the working fluid in the sealed space is provided.
The first metal sheet has a heat receiving surface that receives heat from the cooled device.
The second metal sheet has a space-defining surface that defines a part of the sealed space, and a heat-dissipating surface that is provided on a side opposite to the side of the device to be cooled.
The roughened portion has a surface roughness larger than the surface roughness of the spatially defined surface.
In the step of forming the roughened portion, the roughened portion, the formed on at least a portion of the heat radiation surface is formed on at least a portion of Rutotomoni the heat receiving surface, the manufacturing method of the vapor chamber. The method for manufacturing a vapor chamber according to claim 11 , wherein the roughening step is performed between the defining surface forming step and the joining step. The method for manufacturing a vapor chamber according to claim 11 , wherein the roughening step is performed after the sealing step. The method for manufacturing a vapor chamber according to any one of claims 11 to 13 , wherein in the roughening step, the roughened portion is formed by half etching. The claim that a patterned resist film is formed on the heat-dissipating surface in the roughening step, and then the heat-dissipating surface is half-etched from the resist opening of the resist film to form the roughened portion. 14. The method for manufacturing a vapor chamber according to 14. In the demarcation surface forming step, the space demarcation surface is formed by half etching.
The method for producing a vapor chamber according to claim 14 , wherein the etching solution used in the roughening step has a smaller erosion effect than the etching solution used in the defining surface forming step. The method for manufacturing a vapor chamber according to any one of claims 11 to 13 , wherein in the roughening step, the roughened portion is formed by electroplating. A method for manufacturing a vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
A preparatory step for preparing a first metal sheet to which the cooled device is attached and a second metal sheet, and
A demarcation surface forming step of forming a space demarcation surface that defines the sealed space on at least one of the first metal sheet and the second metal sheet.
The roughening process for forming the roughened portion and
A joining step of joining the first metal sheet and the second metal sheet to form the sealed space between the first metal sheet and the second metal sheet.
A sealing step of sealing the working fluid in the sealed space is provided.
The first metal sheet has a heat receiving surface that receives heat from the cooled device.
The second metal sheet has a space-defining surface that defines a part of the sealed space, and a heat-dissipating surface that is provided on a side opposite to the side of the device to be cooled.
The roughened portion has a surface roughness larger than the surface roughness of the spatially defined surface.
In the step of forming the roughened portion, the roughened portion is formed on at least a part of the heat radiating surface.
The roughened portion is roughened by the grain interface of the crystal of the material or by a plurality of electrodepositions.
A method for manufacturing a vapor chamber, wherein the roughened portion is also formed on an outer peripheral surface extending from the heat radiating surface to the heat receiving surface. The roughened portion is roughened by the plurality of the electrodeposited objects, and the roughened portion is roughened.
The method for manufacturing a vapor chamber according to claim 18, wherein in the roughening step, the electrodeposit is formed by electroplating. The method for manufacturing a vapor chamber according to claim 18 or 19, wherein the roughening step is performed after the sealing step. A method for manufacturing a vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
A preparatory step for preparing a first metal sheet to which the cooled device is attached and a second metal sheet, and
A demarcation surface forming step of forming a space demarcation surface that defines the sealed space on at least one of the first metal sheet and the second metal sheet.
The roughening process for forming the roughened portion and
A joining step of joining the first metal sheet and the second metal sheet to form the sealed space between the first metal sheet and the second metal sheet.
A sealing step of sealing the working fluid in the sealed space is provided.
The second metal sheet has a space-defining surface that defines a part of the sealed space, and a heat-dissipating surface that is provided on a side opposite to the side of the device to be cooled.
The roughened portion has a surface roughness larger than the surface roughness of the spatially defined surface.
In the step of forming the roughened portion, the roughened portion is formed on at least a part of the heat radiating surface.
The roughened portion has a plurality of spaced roughened convex portions.
A method of manufacturing a vapor chamber in which a plurality of roughened convex portions are arranged in two directions intersecting each other. A method for manufacturing a vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
A preparatory step for preparing a first metal sheet to which the cooled device is attached and a second metal sheet, and
A demarcation surface forming step of forming a space demarcation surface that defines the sealed space on at least one of the first metal sheet and the second metal sheet.
The roughening process for forming the roughened portion and
A joining step of joining the first metal sheet and the second metal sheet to form the sealed space between the first metal sheet and the second metal sheet.
A sealing step of sealing the working fluid in the sealed space is provided.
The second metal sheet has a space-defining surface that defines a part of the sealed space, and a heat-dissipating surface that is provided on a side opposite to the side of the device to be cooled.
The roughened portion has a surface roughness larger than the surface roughness of the spatially defined surface.
In the step of forming the roughened portion, the roughened portion is formed on at least a part of the heat radiating surface.
A method for manufacturing a vapor chamber, wherein the roughened portion is roughened by a grain interface of crystals of a material.

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