JP6963740B2 - Vapor chamber and manufacturing method of vapor chamber - Google Patents

Description

The present invention relates to a vapor chamber having a sealed space in which a hydraulic fluid is sealed, a metal sheet assembly 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). 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 part close to the device (evaporation part) and evaporates to vapor, and then the vapor moves to a position away from the evaporation part. Cools and condenses into a liquid. The liquefied hydraulic fluid passes through the liquid 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 hydraulic fluid transfers the heat of the device by refluxing in the vapor chamber while repeating phase change, that is, evaporation and condensation, and enhances heat dissipation efficiency.

JP-A-2007-315745

The vapor chamber may be made of copper or a copper alloy having good thermal conductivity in order to enhance the heat dissipation effect. Therefore, when the thickness of the vapor chamber is reduced in order to make the mobile terminal compact, the rigidity of the vapor chamber can be a problem. For example, when installing the vapor chamber on a mobile terminal or the like, if an excessive force is applied to the vapor chamber, the vapor chamber may be deformed, so careful handling is required at the time of installation. Further, the sealed space is evacuated before the hydraulic fluid is injected into the sealed space of the vapor chamber. In this case as well, the vapor chamber may be deformed due to the differential pressure inside and outside the vapor chamber. Further, when other parts or the like are joined to the vapor chamber by soldering, there is a possibility that the vapor chamber may be deformed due to thermal expansion.

Further, as described above, when the vapor chamber is operated, a part of the vapor chamber is in contact with the liquid hydraulic fluid, and the other part is in contact with the vapor of the hydraulic fluid. As a result, a temperature distribution is generated in the vapor chamber, and the elongation due to thermal expansion of each part is different. Therefore, there is also a problem that the vapor chamber is deformed due to warpage.

When the vapor chamber is deformed in this way, the vapor of the hydraulic fluid in the sealed space and the flow path area of the flow path through which the liquid hydraulic fluid flows are reduced, and the vapor chamber may not operate normally.

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 combination for a vapor chamber, and a method for manufacturing a vapor chamber capable of suppressing deformation.

The present invention is a vapor chamber that has a sealed space in which a working fluid is sealed and cools a device to be cooled, and is provided on a lower metal sheet to which the device to be cooled is attached and the lower metal sheet. The vapor chamber is deformed by being provided on at least one of the upper metal sheet forming the sealing space between the lower metal sheet, the lower surface of the lower metal sheet, and the upper surface of the upper metal sheet. Provided is a vapor chamber provided with a deformation suppressing member for suppressing.

Further, in the above-mentioned vapor chamber, the deformation suppressing member is provided on the lower surface of the lower metal sheet, and the bending strength of the deformation suppressing member provided on the lower surface of the lower metal sheet is the lower side. It may be greater than the bending strength of the metal sheet.

Further, in the above-mentioned vapor chamber, the front deformation suppressing member is provided on the lower surface of the lower metal sheet, and the coefficient of thermal expansion of the deformation suppressing member provided on the lower surface of the lower metal sheet is the above. It may be larger than the coefficient of thermal expansion of the lower metal sheet.

Further, in the above-mentioned vapor chamber, the deformation suppressing member is provided on the upper surface of the upper metal sheet, and the bending strength of the deformation suppressing member provided on the upper surface of the upper metal sheet is the bending strength of the upper metal sheet. It may be greater than the bending strength.

Further, in the above-mentioned vapor chamber, the deformation suppressing member is provided on the upper surface of the upper metal sheet, and the coefficient of thermal expansion of the deformation suppressing member provided on the upper surface of the upper metal sheet is the coefficient of thermal expansion of the upper metal sheet. It may be smaller than the coefficient of thermal expansion of.

Further, in the above-mentioned vapor chamber, the deformation suppressing member may be made of stainless steel.

Further, in the above-mentioned vapor chamber, the deformation suppressing member may include a plating layer.

Further, in the above-mentioned vapor chamber, the lower metal sheet and the upper metal sheet may be formed of copper or a copper alloy.

Further, the present invention is a combination of metal sheets for a vapor chamber for a vapor chamber that has a sealed space in which a working fluid is sealed and cools a device to be cooled, and the metal sheet for the vapor chamber and the vapor chamber. Provided is a metal sheet assembly for a vapor chamber, which is provided on one surface of the metal sheet for vapor chamber and includes a deformation suppressing member for suppressing deformation of the vapor chamber.

Further, the present invention is a method for manufacturing a vapor chamber formed between a lower metal sheet and an upper metal sheet, which has a sealed space in which a working liquid is sealed and cools a device to be cooled. The step of preparing the lower metal sheet to which the device to be cooled is attached and the upper metal sheet, and joining the lower metal sheet and the upper metal sheet to the lower metal sheet and the upper metal sheet. After joining the lower metal sheet and the upper metal sheet with the step of forming the sealed space between the two, the lower surface of the lower metal sheet and the upper surface of the upper metal sheet are covered with the above. Provided is a method for manufacturing a vapor chamber, comprising a step of providing a deformation suppressing member for suppressing deformation of the vapor chamber and a step of enclosing the working liquid in the sealed space.

Further, the present invention is a method for manufacturing a vapor chamber formed between a lower metal sheet and an upper metal sheet, which has a sealed space in which a working liquid is sealed and cools a device to be cooled. Deformation of the vapor chamber to the step of preparing the lower metal sheet to which the device to be cooled is attached and the upper metal sheet, and to at least one of the lower surface of the lower metal sheet and the upper surface of the upper metal sheet. The step of providing the deformation suppressing member, and the lower metal sheet provided with the deformation suppressing member on at least one side and the upper metal sheet are joined to each other, and between the lower metal sheet and the upper metal sheet. Provided is a method for manufacturing a vapor chamber, comprising a step of forming the sealed space and a step of enclosing the working liquid in the sealed space.

Further, in the above-described method for manufacturing a vapor chamber, in the step of providing the deformation suppressing member, the deformation suppressing member is attached to at least one of the lower surface of the lower metal sheet and the upper surface of the upper metal sheet with an adhesive. It may be joined by brazing, soldering, diffusion bonding, or laser welding.

Further, in the above-described method for manufacturing a vapor chamber, in the step of providing the deformation suppressing member, the deformation suppressing member is plated on at least one of the lower surface of the lower metal sheet and the upper surface of the upper metal sheet. It may be formed.

According to the present invention, deformation can be suppressed.

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. FIG. 5 is a top view showing the lower metal sheet of FIG. FIG. 6 is a bottom view showing the upper metal sheet of FIG. FIG. 7 is a front view showing a measuring instrument used for measuring bending strength. FIG. 8 is a diagram for explaining a process of measuring bending strength using the measuring instrument of FIG. 7. FIG. 9 is a diagram for explaining a step of preparing the lower metal sheet in the method for manufacturing the vapor chamber of FIG. 1. FIG. 10 is a diagram for explaining a half-etching step of the lower metal sheet in the method for manufacturing the vapor chamber of FIG. 1. FIG. 11 is a diagram for explaining a wick mounting process in the method for manufacturing the vapor chamber of FIG. 1. FIG. 12 is a diagram for explaining a temporary fixing step in the method for manufacturing the vapor chamber of FIG. 1. FIG. 13 is a diagram for explaining a diffusion joining step in the method for manufacturing the vapor chamber of FIG. 1. FIG. 14 is a diagram for explaining a joining process of the deformation suppressing member in the method for manufacturing the vapor chamber of FIG. 1. FIG. 15 is a diagram for explaining a process of filling the hydraulic fluid in the method for manufacturing the vapor chamber of FIG. FIG. 16 is a diagram for explaining a modification of the method for manufacturing the vapor chamber of FIG. 1.

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.

Embodiments of the present invention will be described with reference to FIGS. 1 to 15. The vapor chamber 1 in the present embodiment has a sealed space 3 in which the hydraulic fluid 2 is sealed, and the hydraulic fluid 2 in the sealed space 3 repeats a phase change to cause a mobile terminal such as a mobile terminal or a tablet terminal. This is a device for cooling a device D (cooled device) that generates heat, such as a central processing unit (CPU) used in the above. The vapor chamber 1 is formed in a substantially thin flat plate shape.

As shown in FIGS. 1 to 4, the vapor chamber 1 includes a lower metal sheet 10 and an upper metal sheet 20 provided on the lower metal sheet 10. The lower metal sheet 10 and the upper metal sheet 20 both correspond to metal sheets for vapor chambers. 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 portion 11 described later) via the lower deformation suppressing member 31 described later. 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 hydraulic 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 direction orthogonal to the surface of the vapor chamber 1 that receives heat from the device D (lower surface 10b of the lower metal sheet 10) and the surface that releases the received heat (upper surface 20b of the upper metal sheet 20). The state viewed from above corresponds to, for example, a state in which the vapor chamber 1 is viewed from above (see FIG. 1) or a state in which the vapor chamber 1 is viewed 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. do.

As shown in FIGS. 1 to 5, the lower metal sheet 10 is provided on the upper surface 10a (the surface on the side of the upper metal sheet 20) and the evaporation portion 11 in which the hydraulic fluid 2 evaporates to generate vapor, and is a flat surface. It has a lower flow path recess 12 formed in a rectangular shape visually. Of these, the lower flow path recess 12 constitutes a part of the sealed space 3 described above, and mainly evaporates the hydraulic fluid 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 hydraulic fluid 2 in the sealed space 3 evaporates by receiving heat from the device D attached to the lower surface 10b of the lower metal sheet 10. Therefore, the term evaporating unit 11 is used not only as a concept that is limited to the portion that overlaps with the device D, but also as a concept that includes a portion that allows the hydraulic fluid 2 to evaporate even if it does not overlap with the device D. Here, the evaporation portion 11 can be provided at an arbitrary location on the lower metal sheet 10, but FIG. 5 shows an example in which the evaporation portion 11 is provided at the central portion of the lower metal sheet 10. 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 the present embodiment, as shown in FIGS. 1, 2, 4, and 5, from the bottom surface 12a (described later) of the lower flow path recess 12 into the lower flow path recess 12 of the lower metal sheet 10. A plurality of lower flow path protrusions 13 are provided so as to project upward (in a direction perpendicular to the bottom surface 12a). 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. Further, each lower flow path protrusion 13 extends along the longitudinal direction (left-right direction in FIGS. 1 and 5) of the vapor chamber 1 and is arranged at equal intervals. Further, the lower flow path protrusion 13 is also arranged along the transverse direction of the vapor chamber 1 (horizontal direction orthogonal to the longitudinal direction, vertical direction in FIGS. 1 and 5). 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.

As shown in FIGS. 2 to 4, a wick W is provided in a portion of the lower flow path recess 12 excluding the evaporation portion 11. 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. The wick W may be provided in the entire area 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. Further, the wick W provided around the evaporation unit 11 on the bottom surface 12a can contribute to effectively transporting the liquid hydraulic fluid 2 to the evaporation unit 11. Further, the wick W is attached so as to be fitted between the lower flow path protrusions 13 of the lower flow path recess 12. 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. 4 and 5, 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. Further, 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. That is, the vapor chamber 1 according to the present embodiment is configured so that when the lower metal sheet 10 is turned upside down, it becomes the upper metal sheet 20, and two metal sheets having the same structure as the lower metal sheet 10 are produced. Then, one of them is turned 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 and 6, the upper metal sheet 20 has an upper flow path recess 21 provided on the lower surface 20a (the surface on the side of the lower metal sheet 10). 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. Further, as shown in FIGS. 2 and 3, a housing member H forming a part of a housing such as a mobile terminal is arranged on the upper surface 20b of the upper metal sheet 20 via an upper deformation suppressing member 32 described later. .. As a result, the steam in the upper flow path recess 21 is cooled by the outside air via the upper metal sheet 20, the upper deformation suppressing member 32, and the housing member H.

In the present embodiment, as shown in FIGS. 1 and 6, the ceiling surface 21a of the upper flow path recess 21 (when the upper metal sheet 20 is turned upside down) is inside the upper flow path recess 21 of the upper metal sheet 20. Is provided with a plurality of upper flow path protrusions 22 protruding downward (in a direction perpendicular to the ceiling surface 21a) from (corresponding to the bottom surface of the upper flow path recess 21). 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. Further, the upper flow path protrusions 22 extend along the longitudinal direction of the vapor chamber 1 and are arranged at equal intervals. 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 hydraulic fluid 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. ..

As shown in FIGS. 4 and 6, 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. Further, 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 come into contact with each other and are below. 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, 5 and 6, the vapor chamber 1 has an injection portion 4 for injecting the hydraulic fluid 2 into the sealed space 3 at one end of a pair of ends in the longitudinal direction. Further prepared. 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. No.

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 dissipation efficiency of the vapor chamber 1 can be improved. The thickness T0 of the vapor chamber 1 excluding the lower deformation suppressing member 31 and the upper deformation suppressing member 32, which will be described later, is 0.1 mm to 1.0 mm. The thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 are halved from the thickness of the vapor chamber 1 excluding the deformation suppressing members 31 and 32 in order to improve handling, and T1 and T2 are reduced. It is preferable to make them equal.

Next, the lower deformation suppressing member 31 and the upper deformation suppressing member 32 will be described with reference to FIGS. 1 to 4, 7 and 8.

As shown in FIGS. 1 to 4, deformation suppressing members for suppressing deformation of the vapor chamber 1 are provided on the lower surface 10b of the lower metal sheet 10 and the upper surface 20b of the upper metal sheet 20. In the present embodiment, the deformation suppressing member provided on the lower surface 10b of the lower metal sheet 10 is referred to as the lower deformation suppressing member 31, and the deformation suppressing member provided on the upper surface 20b of the upper metal sheet 20 is referred to as the upper deformation suppressing member. It is called 32. When the vapor chamber 1 is installed in a housing such as a mobile terminal, the lower deformation suppressing member 31 is interposed between the lower surface 10b of the lower metal sheet 10 and the device D which is a cooling target. The upper deformation suppressing member 32 is interposed between the upper surface 20b of the upper metal sheet 20 and the housing member H when the vapor chamber 1 is installed in a housing such as a mobile terminal. Further, in the present embodiment, the lower deformation suppressing member 31 and the upper deformation suppressing member 32 are formed in a flat plate shape and in a rectangular shape in a plan view, and the lower surface 10b and the upper metal of the lower metal sheet 10 are formed. It is provided in the entire area of the upper surface 20b of the sheet 20. However, the shape is not limited to this, and the shapes of the lower deformation suppressing member 31 and the upper deformation suppressing member 32 can be arbitrary as long as the deformation of the vapor chamber 1 can be suppressed. The thickness T3 of the lower deformation suppressing member 31 and the thickness T4 of the upper deformation suppressing member 32 can be arbitrary as long as the deformation of the vapor chamber 1 can be suppressed, although they depend on the respective strengths. For example, it can be 0.1 mm to 0.15 mm.

It is preferable that the bending strength of the lower deformation suppressing member 31 is larger than the bending strength of the lower metal sheet 10. As a result, the lower metal sheet 10 and the upper metal sheet 20 can be effectively reinforced by the lower deformation suppressing member 31. Further, it is preferable that the bending strength of the upper deformation suppressing member 32 is larger than the bending strength of the upper metal sheet 20. As a result, the lower metal sheet 10 and the upper metal sheet 20 can be effectively reinforced by the upper deformation suppressing member 32. Here, the term bending strength is used to mean the bending strength obtained by the three-point bending test method specified below.

As a measuring instrument used for measuring bending strength, a combination of a tensile tester (for example, Autograph AGS-H manufactured by Shimadzu Corporation) and a jig for a three-point bending test manufactured for a three-point bending test is used. Use. That is, as shown in FIG. 7, the measuring instrument 50 includes an indenter 52 that presses the test piece 51 from above the test piece 51, and a pair of support tools 53 that support the test piece 51 from below. The indenter 52 is formed in a rod shape so as to extend along the test piece 51 in a direction perpendicular to the paper surface of FIG. Of the indenter 52, the radius R of the tip portion 52a in contact with the test piece 51 is 1.5 mm. The dimensions of the indenter 52 and the support 53 in the depth direction of the paper surface of FIG. 7 are about 100 mm. The distance L1 between the pair of supports 53 is 100 mm.

The test piece 51 to be measured is formed in a rectangular flat plate shape. The length L2 of the test piece 51 is about 150 mm, the width of the test piece 51 (the dimension of the test piece 51 in the depth direction of the paper surface in FIG. 7) is about 75 mm, and the thickness T5 of the test piece 51 is about 0.3 mm. Then, three such test pieces 51 are prepared. The alignment of the test piece 51, the indenter 52, and the support 53 to be measured is visually performed so that the centers of the test pieces 51, the indenter 52, and the support 53 are aligned with each other.

At the time of measurement, as shown in FIG. 8, first, both ends of the test piece 51 are placed on the support 53. At this time, both ends of the test piece 51 are simply placed without being restrained by the support 53. Next, the indenter 52 is brought into contact with the upper surface of the test piece 51. Subsequently, the indenter 52 is lowered at a constant lowering speed (0.5 mm / s) from the contact point with the test piece 51 to 30 mm. Then, the indenter 52 is raised and the indenter 52 is pulled away from the test piece 51. While lowering the indenter 52, the maximum load applied to the indenter 52 is measured. Then, the maximum load is measured with the three test pieces 51 in the same manner, and the average value of the obtained maximum loads is taken as the bending strength according to the present embodiment.

Further, it is preferable that the coefficient of thermal expansion of the lower deformation suppressing member 31 is larger than the coefficient of thermal expansion of the lower metal sheet 10. In this case, when the vapor chamber 1 is operated, the elongation due to thermal expansion of the lower metal sheet 10 which can be smaller than that of the upper metal sheet 20 can be increased.

Further, it is preferable that the coefficient of thermal expansion of the upper deformation suppressing member 32 is smaller than the coefficient of thermal expansion of the upper metal sheet 20. In this case, when the vapor chamber 1 is operated, the elongation due to thermal expansion of the upper metal sheet 20 which can be larger than that of the lower metal sheet 10 can be reduced.

By the way, the material used for the lower deformation suppressing member 31 and the upper deformation suppressing member 32 is not particularly limited as long as the deformation of the vapor chamber 1 can be suppressed. For example, the lower deformation suppressing member 31 and the upper deformation suppressing member 32 are preferably made of stainless steel such as SUS304 and SUS316L.

For example, a case where the lower metal sheet 10 is made of copper and the lower deformation suppressing member 31 is made of SUS304 will be described. The coefficient of thermal expansion of copper from 0 ° C. to 100 ° C. is 16.6 × 10 ^-6 / K, and the coefficient of thermal expansion of SUS304 from 0 ° C. to 100 ° C. is 17.3 × 10 ^-6 / K. Therefore, the coefficient of thermal expansion of the lower deformation suppressing member 31 can be made larger than the coefficient of thermal expansion of the lower metal sheet 10.

Further, a case where the upper metal sheet 20 is made of copper and the upper deformation suppressing member 32 is made of SUS316L will be described. The coefficient of thermal expansion of SUS316L from 0 ° C. to 100 ° C. is 16.0 × ^10-6 / K. Therefore, the coefficient of thermal expansion of the upper deformation suppressing member 32 can be made smaller than the coefficient of thermal expansion of the upper metal sheet 20.

When the lower deformation suppressing member 31 and the upper deformation suppressing member 32 are made of stainless steel as described above, the lower metal sheet is formed by adhesive, brazing, soldering, diffusion joining, laser welding, or the like. It can be attached to the 10 and the upper metal sheet 20.

The lower deformation suppressing member 31 and the upper deformation suppressing member 32 are not limited to being made of stainless steel. For example, the lower deformation suppressing member 31 and the upper deformation suppressing member 32 may be formed of a hard metal such as iron, nickel, cobalt, titanium, chromium, molybdenum, or an alloy thereof.

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. 9 to 15, but the description of the half-etching step of the upper metal sheet 20 will be simplified. In addition, in FIGS. 9 to 15, the cross section similar to the cross section of FIG. 4 is shown.

First, as shown in FIG. 9, a flat plate-shaped lower metal sheet 10 is prepared. The lower metal sheet 10 prepared here has an outer contour shape as shown in FIG.

Subsequently, as shown in FIG. 10, the lower metal sheet 10 is half-etched to form the lower flow path recess 12 that forms a part of the sealed space 3. In this case, first, a resist film (not shown) is formed on the upper surface 10a of the lower metal sheet 10 in a pattern corresponding to the plurality of lower flow path protrusions 13 and the lower peripheral wall 14 by a photolithography technique. Subsequently, as a half-etching step, the upper surface 10a of the lower metal sheet 10 is half-etched. As a result, the portion of the upper surface 10a of the lower metal sheet 10 corresponding to the opening (not shown) of the resist film is half-etched, and the lower flow path recess 12 and the lower flow path as shown in FIG. The protrusion 13 and the lower peripheral wall 14 are formed. At this time, the lower injection flow path recess 17 shown in FIGS. 1 and 5 is also formed at the same time. After the half-etching step, the 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 lower metal sheet 10. 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.

On the other hand, in the same manner as the lower metal sheet 10, the upper metal sheet 20 is half-etched from the lower surface 20a to form the upper flow path recess 21, the upper flow path protrusion 22, and the upper peripheral wall 23. In this way, the above-mentioned upper metal sheet 20 is obtained.

Next, as shown in FIG. 11, the wick W is inserted and fitted between the lower flow path protrusions 13 of the lower flow path recess 12.

Next, as shown in FIG. 12, 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 alignment hole 15 (see FIGS. 1 and 5) of the lower metal sheet 10 and the upper alignment hole 24 (see FIGS. 1 and 6) of the upper metal sheet 20 are used to lower the lower side. The metal sheet 10 and the upper metal sheet 20 are positioned. Subsequently, the lower metal sheet 10 and the upper metal sheet 20 are fixed. The method of fixing is not particularly limited, but for example, the lower metal sheet 10 and the upper metal sheet 20 are fixed by performing resistance welding to the lower metal sheet 10 and the upper metal sheet 20. You may. In this case, as shown in FIG. 12, it is preferable to perform spot resistance welding using the electrode rod 40. Laser welding may be performed instead of resistance welding. Alternatively, the lower metal sheet 10 and the upper metal sheet 20 may be ultrasonically bonded and fixed by irradiating ultrasonic waves. Further, although an adhesive may be used, it is preferable to use an adhesive having no organic component or having a small amount of organic component. In this way, the lower metal sheet 10 and the upper metal sheet 20 are fixed in a positioned state.

After the temporary fixing, as shown in FIG. 13, 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 joined are brought into close contact with each other, and pressure is applied in a direction in which the metal sheets 10 and 20 are brought into close contact with each other in a controlled atmosphere such as in a vacuum or in an inert gas. It is a method of joining by heating together with the diffusion of atoms generated on the joining surface. 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 5) and the upper injection flow path recess 26 (see FIGS. 1 and 6) 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 permanent joining, as shown in FIG. 14, the lower deformation suppressing member 31 is joined to the lower surface 10b of the lower metal sheet 10, and the upper deformation suppressing member 32 is joined to the upper surface 20b of the upper metal sheet 20. Will be done. In this case, for example, the lower metal sheet 10 and the lower deformation suppressing member 31, and the upper metal sheet 20 and the upper deformation suppressing member 32 are joined by an adhesive, brazing, soldering, diffusion joining, laser welding, or the like. You may. Further, the lower deformation suppressing member 31 and the upper deformation suppressing member 32 may be formed by plating on the lower surface 10b of the lower metal sheet 10 and the upper surface 20b of the upper metal sheet 20.

Next, as shown in FIG. 15, the hydraulic fluid 2 is injected into the sealed space 3 from the injection unit 4 (see FIG. 1). At this time, first, the sealed space 3 is evacuated and depressurized, and then the hydraulic fluid 2 is injected into the sealed space 3. At the time of injection, the hydraulic 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 the injection of the hydraulic fluid 2, the injection flow path described above 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 is an object to be cooled on the lower surface 10b of the lower metal sheet 10 via the lower deformation suppressing member 31. A device D such as a CPU is attached. At this time, the bending strength of the lower deformation suppressing member 31 is larger than the bending strength of the lower metal sheet 10, and the bending strength of the upper deformation suppressing member 32 is larger than the bending strength of the upper metal sheet 20. As a result, the lower metal sheet 10 and the upper metal sheet 20 are reinforced by the lower deformation suppressing member 31 and the upper deformation suppressing member 32, and the rigidity of the vapor chamber 1 is effectively increased. Therefore, when the vapor chamber 1 is installed in the housing of a mobile terminal or the like, the deformation of the vapor chamber 1, especially the bending deformation, is suppressed.

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 hydraulic fluid 2 existing in the evaporation portion 11 of the lower flow path recess 12 receives heat from the device D via the lower deformation suppressing member 31. The received heat is absorbed as latent heat and the hydraulic fluid 2 evaporates (vaporizes) to generate vapor of the hydraulic fluid 2. 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 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. The diffused steam dissipates heat to the upper metal sheet 20 and is cooled. The heat received from the steam by the upper metal sheet 20 is transferred to the outside air via the housing member H (see FIGS. 2 and 3).

By radiating heat to the upper metal sheet 20, the steam loses the latent heat absorbed in the evaporation unit 11 and condenses. Most of the liquefied hydraulic fluid 2 descends in the upper flow path recess 21 and reaches the lower flow path recess 12. Since the hydraulic fluid 2 continues to evaporate in the evaporation section 11, the hydraulic fluid 2 in the lower flow path recess 12 other than the evaporation section 11 is transported toward the evaporation section 11. 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 hydraulic fluid 2 obtains a propulsive force toward the evaporation unit 11 and is smoothly transported toward the evaporation unit 11.

The hydraulic fluid 2 that has reached the evaporation unit 11 receives heat again from the device D and evaporates. In this way, the hydraulic 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.

By the way, when the vapor chamber 1 is operated, as described above, the hydraulic fluid 2 receives heat from the device D, and the vapor of the hydraulic fluid 2 is generated. Then, the generated steam mainly diffuses into the upper flow path recess 21. Therefore, the lower metal sheet 10, the upper metal sheet 20, the lower deformation suppressing member 31, and the upper deformation suppressing member 32 thermally expand. Further, as described above, the lower flow path recess 12 of the lower metal sheet 10 mainly transports the liquid hydraulic fluid 2 having a relatively low temperature. As a result, the elongation due to thermal expansion of the upper metal sheet 20 can be larger than the elongation due to thermal expansion of the lower metal sheet 10. Therefore, the vapor chamber 1 may be warped due to the difference between the elongation due to the thermal expansion of the lower metal sheet 10 and the elongation due to the thermal expansion of the upper metal sheet 20.

However, in the present embodiment, the lower deformation suppressing member 31 having a bending strength larger than that of the lower metal sheet 10 is provided on the lower surface 10b of the lower metal sheet 10. Further, an upper deformation suppressing member 32 having a bending strength higher than that of the upper metal sheet 20 is provided on the upper surface 20b of the upper metal sheet 20. As a result, the lower metal sheet 10 and the upper metal sheet 20 are reinforced by the lower deformation suppressing member 31 and the upper deformation suppressing member 32. Therefore, the rigidity of the vapor chamber 1 is ensured, and the deformation of the vapor chamber 1 is suppressed.

Further, in the present embodiment, the coefficient of thermal expansion of the lower deformation suppressing member 31 is larger than the coefficient of thermal expansion of the lower metal sheet 10. As a result, the elongation of the lower deformation suppressing member 31 due to thermal expansion is larger than the elongation of the lower metal sheet 10 due to thermal expansion. Therefore, the lower deformation suppressing member 31 increases the elongation of the lower metal sheet 10. Further, the coefficient of thermal expansion of the upper deformation suppressing member 32 is smaller than the coefficient of thermal expansion of the upper metal sheet 20. As a result, the elongation of the upper deformation suppressing member 32 due to thermal expansion is smaller than the elongation of the upper metal sheet 20 due to thermal expansion. Therefore, the upper deformation suppressing member 32 reduces the elongation of the upper metal sheet 20 due to thermal expansion. As a result, the difference between the elongation due to thermal expansion of the lower metal sheet 10 and the elongation due to thermal expansion of the upper metal sheet 20 becomes smaller. Therefore, the deformation due to the warp of the vapor chamber 1 due to the difference between the elongation due to the thermal expansion of the lower metal sheet 10 and the elongation due to the thermal expansion of the upper metal sheet 20 is suppressed.

As described above, according to the present embodiment, the lower deformation suppressing member 31 is provided on the lower surface 10b of the lower metal sheet 10, and the upper deformation suppressing member 32 is provided on the upper surface 20b of the upper metal sheet 20. As a result, deformation of the vapor chamber 1 can be suppressed. Therefore, it is possible to prevent the flow path area of the lower flow path recess 12 and the upper flow path recess 21 constituting the sealed space 3 from being reduced due to the deformation of the vapor chamber 1, and the stable operation of the vapor chamber 1 is ensured. can do.

Further, according to the present embodiment, the lower deformation suppressing member 31 having a bending strength higher than that of the lower metal sheet 10 is provided on the lower surface 10b of the lower metal sheet 10 and has a bending strength higher than that of the upper metal sheet 20. The upper deformation suppressing member 32 is provided on the upper surface 20b of the upper metal sheet 20. As a result, the lower metal sheet 10 and the upper metal sheet 20 can be reinforced by the lower deformation suppressing member 31 and the upper deformation suppressing member 32. Therefore, the rigidity of the vapor chamber 1 can be effectively increased, and the deformation of the vapor chamber 1 can be suppressed. In this case, since the deformation of the vapor chamber 1 when the vapor chamber 1 is installed on a mobile terminal or the like can be suppressed, the handling of the vapor chamber 1 can be facilitated. Further, it is possible to suppress the deformation of the vapor chamber 1 when the sealed space 3 is evacuated. Further, it is possible to suppress deformation due to thermal expansion that occurs when other parts or the like are joined to the vapor chamber 1 by soldering.

Further, according to the present embodiment, the coefficient of thermal expansion of the lower deformation suppressing member 31 is larger than the coefficient of thermal expansion of the lower metal sheet 10, and the coefficient of thermal expansion of the upper deformation suppressing member 32 is the upper metal sheet 20. It is smaller than the coefficient of thermal expansion of. As a result, the elongation of the lower deformation suppressing member 31 due to thermal expansion can be made larger than the elongation of the lower metal sheet 10 due to thermal expansion, and the elongation of the upper deformation suppressing member 32 due to thermal expansion can be increased by the thermal expansion of the upper metal sheet 10. It can be made smaller than the elongation due to thermal expansion of 20. Therefore, the lower deformation suppressing member 31 can increase the elongation of the lower metal sheet 10, and the upper deformation suppressing member 32 can reduce the elongation of the upper metal sheet 20. As a result, the difference between the elongation due to thermal expansion of the lower deformation suppressing member 31 and the elongation due to thermal expansion of the upper deformation suppressing member 32 can be reduced. Therefore, deformation due to warpage of the vapor chamber 1 due to the difference between the elongation due to the thermal expansion of the lower metal sheet 10 and the elongation due to the thermal expansion of the upper metal sheet 20 can be suppressed.

In the above-described embodiment, the deformation suppressing members 31 and 32 for suppressing the deformation of the vapor chamber 1 are provided on the lower surface 10b of the lower metal sheet 10 and the upper surface 20b of the upper metal sheet 20. explained. However, the present invention is not limited to this, and for example, the deformation suppressing members 31 and 32 may not be provided on either the lower surface 10b of the lower metal sheet 10 or the upper surface 20b of the upper metal sheet 20. Even in this case, the deformation of the vapor chamber 1 can be suppressed by the lower deformation suppressing member 31 or the upper deformation suppressing member 32. When the lower deformation suppressing member 31 is not provided, the device D (see FIGS. 1 to 3 and 5) has a lower metal sheet 10 when the vapor chamber 1 is installed in a housing such as a mobile terminal. It is attached to the lower surface 10b of the. When the upper deformation suppressing member 32 is not provided, the housing member H (see FIGS. 2 and 3) is placed on the upper surface 20b of the upper metal sheet 20 when the vapor chamber 1 is installed in the housing of a mobile terminal or the like. Be placed.

Further, in the above-described embodiment, the bending strength of the lower deformation suppressing member 31 is larger than the bending strength of the lower metal sheet 10, and the bending strength of the upper deformation suppressing member 32 is the bending strength of the upper metal sheet 20. An example in which the strength is higher than the strength has been described. However, it is not limited to this. For example, even if the bending strength of the lower deformation suppressing member 31 is not greater than the bending strength of the lower metal sheet 10, the coefficient of thermal expansion of the lower deformation suppressing member 31 is the thermal expansion of the lower metal sheet 10. It suffices if it is larger than the coefficient. Further, even if the bending strength of the upper deformation suppressing member 32 is not larger than the bending strength of the upper metal sheet 20, the coefficient of thermal expansion of the upper deformation suppressing member 32 is smaller than the coefficient of thermal expansion of the upper metal sheet 20. It should be. In this case, as described above, the difference between the elongation due to thermal expansion of the lower deformation suppressing member 31 and the elongation due to thermal expansion of the upper deformation suppressing member 32 can be reduced. Therefore, deformation due to warpage of the vapor chamber 1 due to the difference between the elongation due to the thermal expansion of the lower metal sheet 10 and the elongation due to the thermal expansion of the upper metal sheet 20 can be suppressed.

Further, in the above-described embodiment, the plurality of lower flow path protrusions 13 are arranged along the longitudinal direction of the vapor chamber 1 and also along the transverse direction of the vapor chamber 1. An example has been described. However, the present invention is not limited to this, and the arrangement of the plurality of lower flow path protrusions 13 is optional as long as it can abut on the upper flow path protrusions 22 and secure the mechanical strength of the vapor chamber 1. be.

Further, in the above-described embodiment, there is an example in which the lower flow path protrusion of the lower metal sheet 10 is formed as a boss and the upper flow path protrusion of the upper metal sheet 20 is formed as a boss. explained. However, it is not limited to this. That is, the vapor generated by the evaporation unit 11 can be diffused into the sealed space 3, and the working fluid 2 condensed from the vapor is transported to the evaporation unit 11, and further, the lower flow path protrusion and the upper flow path. The shapes of the lower flow path protrusion and the upper flow path protrusion are arbitrary as long as they can be brought into contact with the protrusion.

More specifically, at least one of the upper flow path protrusion and the lower flow path protrusion may be formed as an elongated wall (not shown) extending substantially parallel to a predetermined direction. This wall may extend along the longitudinal direction of the vapor chamber 1 or may extend along the radial direction from the evaporation portion 11 in plan view. Also in this case, it is preferable that the lower flow path protrusion and the upper flow path protrusion are arranged so as to overlap each other in a plan view.

Further, the upper metal sheet 20 is formed in a flat plate shape and does not have to have the upper flow path recess 21. In this case, the vapor of the hydraulic fluid 2 evaporated in the evaporation unit 11 diffuses in the lower flow path recess 12 of the lower metal sheet 10, dissipates heat to the upper metal sheet 20, is cooled, and is condensed. That is, the entire sealed space 3 is composed of the lower flow path recess 12. Further, when the upper metal sheet 20 is formed in a flat plate shape, the mechanical strength of the vapor chamber 1 can be improved.

Further, in the above-described embodiment, after the lower metal sheet 10 and the upper metal sheet 20 are diffusion-bonded as a permanent joint, the lower deformation suppressing member 31 is attached to the lower surface 10b of the lower metal sheet 10. The example in which the upper deformation suppressing member 32 is joined to the upper surface 20b of the upper metal sheet 20 has been described. However, the present invention is not limited to this, and for example, as shown in FIG. 16, the deformation suppressing members 31 and 32 are made of the corresponding metal before the lower metal sheet 10 and the upper metal sheet 20 are diffusion-bonded. It may be joined to the sheets 10 and 20. In this case, the lower metal sheet 10 to which the lower deformation suppressing member 31 is joined and the upper metal sheet 20 to which the upper deformation suppressing member 32 is joined are permanently joined by diffusion joining. The lower metal sheet 10 (metal sheet for the vapor chamber) to which the lower deformation suppressing member 31 is joined corresponds to the metal sheet combination 110 for the vapor chamber. Similarly, the upper metal sheet 20 (metal sheet for the vapor chamber) to which the upper deformation suppressing member 32 is joined also corresponds to the metal sheet combination 120 for the vapor chamber. In this case, the deformation suppressing members 31 and 32 are composed of a plating layer 33 deposited on the upper metal sheet 20 or the lower metal sheet 10 by a plating treatment, and the plating layer 33 is joined to the metal sheets 10 and 20. It is preferable to have. Examples of the plating layer 33 include a hard plating layer such as nickel plating, nickel cobalt alloy plating, hard chrome plating, and nickel phosphorus plating. However, also in the deformation example shown in FIG. 16, the deformation suppressing members 31 and 32 are formed separately from the metal sheets 10 and 20 by the material as described in the present embodiment to form the metal sheets 10 and 20. It may be joined.

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.

1 Vapor chamber 2 Hydraulic fluid 3 Sealed space 10 Lower metal sheet 10b Lower surface 11 Evaporating part 12 Lower flow path recess 20 Upper metal sheet 20b Upper surface 21 Upper flow path recess 31 Lower deformation suppressing member 32 Upper deformation suppressing member 110, 120 Metal sheet combination D device for vapor chamber

Claims (11)

A vapor chamber that has a sealed space in which a hydraulic fluid is sealed and cools a device to be cooled.
The lower metal sheet to which the cooled device is attached and
An upper metal sheet that forms the sealing space between the lower metal sheet and the lower metal sheet,
Each of the lower surface of the lower metal sheet and the upper surface of the upper metal sheet is provided with a deformation suppressing member that suppresses the deformation of the vapor chamber.
A flow path wall portion is provided in the sealed space, and a flow path wall portion is provided.
The flow path wall portion is formed from the surface of the lower metal sheet that defines the sealing space from the lower surface side to the surface of the upper metal sheet that defines the sealing space from the upper surface side. ,
The coefficient of thermal expansion of the deformation suppressing member provided on the lower surface of the lower metal sheet is larger than the coefficient of thermal expansion of the lower metal sheet.
A vapor chamber in which the coefficient of thermal expansion of the deformation suppressing member provided on the upper surface of the upper metal sheet is smaller than the coefficient of thermal expansion of the upper metal sheet. The vapor chamber according to claim 1, wherein a capillary structure is provided on the side of the sealed space of the lower metal sheet. Bending strength of the deformation suppressing member provided in the lower surface of the front Symbol lower metal sheet is larger than the bending strength of the lower metal sheet, vapor chamber according to claim 1 or 2. Bending strength before Symbol upper metal sheet the upper surface the deformation suppressing member provided in the can, the upper metal greater than the bending strength of the sheet, vapor chamber according to any one of claims 1 to 3. The vapor chamber according to any one of claims 1 to 4 , wherein the deformation suppressing member is made of stainless steel. The vapor chamber according to any one of claims 1 to 5 , wherein the deformation suppressing member includes a plating layer. The vapor chamber according to any one of claims 1 to 6 , wherein the lower metal sheet and the upper metal sheet are formed of copper or a copper alloy. A method for manufacturing a vapor chamber having a sealed space formed between a lower metal sheet and an upper metal sheet in which a hydraulic fluid is sealed and cooling a device to be cooled.
A step of preparing the lower metal sheet to which the cooled device is attached and the upper metal sheet, and
A step of joining the lower metal sheet and the upper metal sheet to form the sealed space between the lower metal sheet and the upper metal sheet.
After joining the lower metal sheet and the upper metal sheet, a step of providing a deformation suppressing member for suppressing deformation of the vapor chamber on each of the lower surface of the lower metal sheet and the upper surface of the upper metal sheet.
The step of enclosing the working fluid in the sealed space is provided.
A flow path wall portion is provided in the sealed space, and a flow path wall portion is provided.
The flow path wall portion is formed from the surface of the lower metal sheet that defines the sealing space from the lower surface side to the surface of the upper metal sheet that defines the sealing space from the upper surface side. ,
The coefficient of thermal expansion of the deformation suppressing member provided on the lower surface of the lower metal sheet is larger than the coefficient of thermal expansion of the lower metal sheet.
A method for manufacturing a vapor chamber, wherein the coefficient of thermal expansion of the deformation suppressing member provided on the upper surface of the upper metal sheet is smaller than the coefficient of thermal expansion of the upper metal sheet. A method for manufacturing a vapor chamber having a sealed space formed between a lower metal sheet and an upper metal sheet in which a hydraulic fluid is sealed and cooling a device to be cooled.
A step of preparing the lower metal sheet to which the cooled device is attached and the upper metal sheet, and
A step of providing a deformation suppressing member for suppressing deformation of the vapor chamber on each of the lower surface of the lower metal sheet and the upper surface of the upper metal sheet.
A step of forming the sealed space between and joining the front Symbol deformation suppressing the lower metal sheet member is provided with the upper metal sheet, and the lower metal sheet and the upper metal sheet,
The step of enclosing the working fluid in the sealed space is provided.
A flow path wall portion is provided in the sealed space, and a flow path wall portion is provided.
The flow path wall portion is formed from the surface of the lower metal sheet that defines the sealing space from the lower surface side to the surface of the upper metal sheet that defines the sealing space from the upper surface side. ,
The coefficient of thermal expansion of the deformation suppressing member provided on the lower surface of the lower metal sheet is larger than the coefficient of thermal expansion of the lower metal sheet.
A method for manufacturing a vapor chamber, wherein the coefficient of thermal expansion of the deformation suppressing member provided on the upper surface of the upper metal sheet is smaller than the coefficient of thermal expansion of the upper metal sheet. In the step of providing the deformation suppressing member, the deformation suppressing member, on the lower surface and the upper surface of the upper metal sheet of the bottom metal sheet, adhesive, brazing, soldering, diffusion bonding, any of laser welding The method for manufacturing a vapor chamber according to claim 8 or 9, which is joined by soldering. In the step of providing the deformation suppressing member, the deformation suppressing member, on the lower surface and the upper surface of the upper metal sheet of the bottom metal sheet is formed by plating, the vapor chamber according to claim 8 or 9 Production method.

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