Vapor chamber and method for manufacturing the same

Abstract

The heat spreader has a working fluid in an internal space formed between the first metal sheet and the second metal sheet. The first metal sheet has a recessed flow path, at least one protrusion and at least one flow groove. The recessed flow path is arranged on the inner surface of the first metal sheet, the protrusion protrudes from the inner surface of the first metal sheet toward the inner surface of the second metal sheet, and the top surface of the protrusion abuts against the inner surface of the second metal sheet. The flow groove has a bottom groove portion, a side groove portion and a top groove portion. The bottom groove portion is arranged on the bottom surface of the recessed flow path, the side groove portion is arranged on the side of the protrusion and connected to the bottom groove portion, and the top groove portion is arranged on the top surface of the protrusion and connected to the side groove portion.

Description

Technical Field

[0001] The invention relates to a vapor chamber and a method for manufacturing the vapor chamber. Background Art

[0002] Electronic components such as semiconductors installed in electrical and electronic devices such as laptop computers, digital cameras, and mobile phones tend to generate more heat due to higher performance and higher density. Efficient cooling of these components is essential to ensure that these devices operate normally for extended periods of time.

[0003] For example, Patent Document 1 describes a heat spreader comprising a first metal sheet and a second metal sheet, wherein the first metal sheet has a first flow path recess, a first bottom groove, and a first flow path protrusion. In the heat spreader of Patent Document 1, when viewed along the length of the first bottom groove, the width of the first bottom groove is smaller than the gap between the first flow path protrusion adjacent to the first bottom groove on one side of the width direction of the first bottom groove and the first flow path protrusion adjacent to the first bottom groove on the other side.

[0004] The heat spreader of Patent Document 1 can improve heat transfer efficiency by utilizing the first bottom grooves and the first flow path protrusions having a predetermined relationship. However, it does not fully meet the recent increasing demand for cooling performance in electrical and electronic equipment.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-128208 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] An object of the present invention is to provide a vapor chamber having excellent heat transfer characteristics and a method for manufacturing the vapor chamber.

[0010] Means for solving problems

[0011] [1] A heat spreader having a working fluid in an internal space formed between a first metal sheet and a second metal sheet, wherein the heat spreader is characterized in that the first metal sheet has a concave flow path, at least one protrusion, and at least one flow path groove.

[0012] The above-mentioned recessed flow path is arranged on the inner surface of the above-mentioned first metal sheet, the above-mentioned protrusion protrudes from the inner surface of the above-mentioned first metal sheet toward the inner surface of the above-mentioned second metal sheet, and the top surface of the above-mentioned protrusion abuts against the above-mentioned inner surface of the above-mentioned second metal sheet, and the above-mentioned flow path groove has a bottom groove portion, a side groove portion and a top groove portion, the above-mentioned bottom groove portion is arranged on the bottom surface of the above-mentioned recessed flow path, the above-mentioned side groove portion is arranged on the side surface of the above-mentioned protrusion and is connected to the above-mentioned bottom groove portion, and the above-mentioned top groove portion is arranged on the above-mentioned top surface of the above-mentioned protrusion and is connected to the above-mentioned side groove portion.

[0013] [2] The heat spreader according to [1] above, wherein the groove depth d of the flow path groove is greater than the groove width w.

[0014] [3] The heat spreader according to [1] or [2] above, wherein the ratio (t2 / t1) of the sheet thickness t2 of the protruding portion of the first metal sheet to the sheet thickness t1 of the recessed flow path of the first metal sheet is greater than 0.1 and less than 10.0.

[0015] [4] The heat spreader according to any one of [1] to [3], wherein the first metal sheet includes a plurality of the flow grooves and has an intersection where the plurality of flow grooves intersect.

[0016] [5] A method for manufacturing a heat spreader, which is the method for manufacturing a heat spreader described in any one of [1] to [4] above, characterized in that it includes a laser processing step of forming at least the side groove portion of the flow path groove of the first metal sheet using a laser.

[0017] [6] The method for manufacturing a heat spreader according to [5] above, wherein the flow channel grooves are formed using a laser in the laser processing step.

[0018] [7] The method for manufacturing a heat spreader according to [5] or [6], further comprising a stamping process for forming the recessed flow path and the protruding portion of the first metal sheet by stamping before the laser processing process.

[0019] [8] The method for manufacturing a heat spreader according to any one of [5] to [7], further comprising a laser welding step of welding the first metal sheet and the second metal sheet using a laser after the laser processing step.

[0020] Effects of the Invention

[0021] According to the present invention, a vapor chamber having excellent heat transfer characteristics and a method for manufacturing the vapor chamber can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A perspective view showing an example of a heat spreader according to an embodiment.

[0023] Figure 2 yes Figure 1 AA line cross-section diagram.

[0024] Figure 3 yes Figure 1 BB line cross-section diagram.

[0025] Figure 4 yes Figure 1 CC line cross-section diagram.

[0026] Figure 5 It is a perspective view showing another example of the heat spreader according to the embodiment.

[0027] Figure 6 It is a perspective view showing another example of the heat spreader according to the embodiment.

[0028] Figure 7 yes Figure 6 AA line cross-section diagram.

[0029] Figure 8 yes Figure 6 BB line cross-section diagram. DETAILED DESCRIPTION

[0030] Hereinafter, detailed description will be given based on the embodiments.

[0031] The inventors of the present application have conducted intensive studies and have found that by suppressing flow disturbance of the liquid-phase working fluid, the liquid-phase and gas-phase working fluids in the vapor chamber can be efficiently circulated, thereby improving heat transfer characteristics.

[0032] The heat spreader of the embodiment has a working fluid in an internal space formed between a first metal sheet and a second metal sheet, the first metal sheet has a recessed flow path, at least one protrusion and at least one flow groove, the recessed flow path is arranged on the inner surface of the first metal sheet, the protrusion protrudes from the inner surface of the first metal sheet toward the inner surface of the second metal sheet, and the top surface of the protrusion abuts against the inner surface of the second metal sheet, the flow groove has a bottom groove portion, a side groove portion and a top groove portion, the bottom groove portion is arranged on the bottom surface of the recessed flow path, the side groove portion is arranged on the side surface of the protrusion and connected to the bottom groove portion, and the top groove portion is arranged on the top surface of the protrusion and connected to the side groove portion.

[0033] Figure 1 This is a perspective view showing an example of a heat spreader according to the embodiment. Figure 2 yes Figure 1 AA line cross-section diagram. Figure 3 yes Figure 1 BB line cross-section diagram. Figure 4 yes Figure 1 The CC line cross section. Figure 1 In the figure, a partial perspective state is shown for convenience in order to understand the internal structure of the heat exchange plate. Figure 1 In FIG. 1 , the flow direction of the liquid-phase working fluid F(L) is indicated by a solid arrow, and the flow direction of the gas-phase working fluid F(G) is indicated by a hollow arrow.

[0034] like Figures 1 to 4 As shown, the heat spreader 1 of the embodiment includes a first metal sheet 10 and a second metal sheet 20. The first metal sheet 10 and the second metal sheet 20 are joined so that the inner surface 10a of the first metal sheet 10 and the inner surface 20a of the second metal sheet 20 are opposite to each other. In other words, the interiors of the first metal sheet 10 and the second metal sheet 20 are sealed. In addition, the heat spreader 1 has a working fluid in the internal space S formed between the first metal sheet 10 and the second metal sheet 20. The internal space S is sealed by the first metal sheet 10 and the second metal sheet 20. The working fluid is enclosed in the internal space S provided inside the heat spreader 1.

[0035] From the viewpoint of the cooling performance of the heat spreader 1 , examples of the working fluid to be sealed in the internal space S include pure water, ethanol, methanol, and acetone.

[0036] The first metal sheet 10 constituting the uniform heat spreader 1 includes a recessed flow path 11 , at least one protruding portion 12 , and at least one flow channel 13 .

[0037] like Figure 1 As shown, the recessed flow path 11 is provided on the inner surface 10a of the first metal sheet 10. The recessed flow path 11 provided on the inner surface 10a is recessed within the range from the outer edge 10c of the first metal sheet 10 to the center of the inner surface 10a. For example, the recessed flow path is the space within the internal space S excluding the protrusion 12 and the flow groove 13. The recessed flow path 11 primarily allows the flow of the gaseous working fluid.

[0038] The protrusion 12 protrudes from the inner surface 10a of the first metal sheet 10 toward the inner surface 20a of the second metal sheet 20 . The top surface 12a of the protrusion 12 abuts against the inner surface 20a of the second metal sheet 20 .

[0039] The shape of the protrusion 12 is not particularly limited as long as the top surface 12a of the protrusion 12 can abut against the inner surface 20a of the second metal sheet 20. Furthermore, when the first metal sheet 10 includes a plurality of protrusions 12, the shapes of the protrusions 12 may all be the same or different. Here, an example is shown in which all the protrusions 12 are cylindrical.

[0040] The flow path groove 13 includes a bottom groove portion 14 , a side groove portion 15 , and a top groove portion 16 .

[0041] like Figure 1 and Figure 4 As shown in FIG. 1 , the bottom groove portion 14 constituting the flow path groove 13 is provided on the bottom surface 11a of the recessed flow path 11. Figure 1 As shown, the side groove portion 15 constituting the flow path groove 13 is provided on the side surface 12b of the protruding portion 12 and is connected to the bottom groove portion 14. Figures 1 to 3 As shown, the top surface groove portion 16 constituting the flow path groove 13 is provided on the top surface 12a of the protrusion 12 and is connected to the side surface groove portion 15. The flow path groove 13 allows the liquid phase working fluid to flow.

[0042] The side groove 15 provided on the side surface 12b of the protrusion 12 extends along the entire length of the side surface 12b, from the bottom to the top. Thus, the side groove 15 extending in the height direction of the protrusion 12 extends across the entire thickness direction of the heat spreader 1 within the internal space S, from the inner surface 10a of the first metal sheet 10 to the inner surface 20a of the second metal sheet 20. Furthermore, the bottom end of the side groove 15 is connected to the bottom groove 14. The top end of the side groove 15 is connected to the top groove 16.

[0043] The groove width w of the flow channel groove 13 is much smaller than the width of the recessed flow channel 11. The shortest width of the recessed flow channel 11 is the shortest distance between adjacent protrusions 12 or the shortest distance between the protrusion 12 and the outer edge 10c of the first metal sheet 10.

[0044] The groove depth d of the flow channel groove 13 is much smaller than the depth of the recessed flow channel 11. The depth of the recessed flow channel 11 is the distance from the inner surface 10a of the outer edge 10c to the bottom surface of the recessed flow channel.

[0045] The liquid-phase working fluid is transported and flows in the flow groove 13 as indicated by the arrow F(L). When a flow groove 13 having a side groove portion 15 extending in the thickness direction of the heat spreader 1 and a bottom groove portion 14 and a top groove portion 16 connected to the side groove portion 15 is provided in the internal space S, not only can the bottom groove portion 14 and the top groove portion 16 suppress the flow turbulence of the liquid-phase working fluid flowing along the in-plane direction of the heat spreader 1, but the side groove portion 15 can also suppress the flow turbulence of the liquid-phase working fluid flowing along the thickness direction of the heat spreader 1, so that the liquid-phase working fluid can also flow well in the thickness direction of the heat spreader 1. If the liquid-phase working fluid can also flow well in the thickness direction of the heat spreader 1, the state in which the liquid-phase working fluid does not exist in the evaporation portion 41, i.e., the so-called dryout, can be suppressed, so that the circulation flow of the liquid-phase and gas-phase working fluids becomes good, thereby improving the heat transfer in the internal space S. Therefore, the heat spreader 1 can have excellent heat transfer characteristics.

[0046] Furthermore, when the flow path grooves 13 are provided in the internal space S, the working fluid flows well along the thickness direction of the heat spreader 1 and the direction perpendicular to the thickness direction of the heat spreader 1, that is, the in-plane direction. Figure 1 When the vapor chamber 1 is in any position, such as when it is tilted 90 degrees on the drawing or turned upside down, the working fluid that has changed from the gas phase to the liquid phase in the condensation section 42 can easily return to the evaporation section 41. In this way, regardless of the configuration of the vapor chamber 1, the circulation flow of the liquid and gas phase working fluids is good, and thus the vapor chamber 1 has excellent heat transfer characteristics.

[0047] Furthermore, when the flow grooves 13 are provided in the internal space S, the evaporation area of ​​the working fluid in the internal space S increases, and the evaporation amount of the working fluid increases. As a result, the heat transfer amount in the internal space S increases, and thus the heat transfer characteristics of the vapor chamber 1 are enhanced.

[0048] In addition, if Figure 1 As shown, with respect to the bottom grooves 14, it is preferable that the ends of the bottom grooves 14 that are different from the ends connected to the side grooves 15 (also referred to as the side groove end of the bottom groove) are connected to each other. If the ends of the bottom grooves 14 that are different from the side groove 15 end are connected to each other, adjacent bottom grooves 14 are connected to each other. This improves the flow of the liquid working fluid along the inner surface 10a of the first metal sheet 10. As a result, the heat transfer characteristics of the vapor chamber 1 are improved.

[0049] In addition, if Figure 1As shown, the top surface grooves 16 preferably have ends different from those connected to the side grooves 15 (also referred to as the side groove-side ends of the top surface grooves) connected to each other. If the ends of the top surface grooves 16 different from the side groove 15 ends are connected to each other, adjacent top surface grooves 16 are connected to each other. This improves the flow of the liquid working fluid along the inner surface 20a of the second metal sheet 20. Consequently, the heat transfer characteristics of the vapor chamber 1 are enhanced.

[0050] Furthermore, the groove depth d of the flow groove 13 is preferably greater than the groove width w. When the groove depth d of the flow groove 13 is greater than the groove width w of the flow groove 13, capillary action is more likely to occur in the flow groove 13 for the liquid-phase working fluid. The capillary action of the flow groove 13 allows the liquid-phase working fluid to flow smoothly within the flow groove 13. Consequently, the heat transfer characteristics of the vapor chamber 1 are further improved.

[0051] In addition, the groove width w of the flow groove 13 is preferably greater than 20 μm and less than 200 μm, and more preferably greater than 50 μm and less than 100 μm. Regarding the groove depth d and groove width w of the flow groove 13, it is preferred that d / w is greater than 2.0 and less than 20.0. If the groove width w and groove depth d of the flow groove 13 are greater than the above lower limits, the flow groove 13 can be easily formed. If the groove width w and groove depth d of the flow groove 13 are less than the above upper limits, the capillary phenomenon of the flow groove 13 easily acts on the working fluid.

[0052] In addition, when the first metal sheet 10 has a plurality of flow grooves 13, it is preferred that the plurality of flow grooves 13 extend parallel to each other. When the plurality of flow grooves 13 extend in parallel, it is preferred that the groove spacing p between adjacent flow grooves 13 is greater than or equal to 40 μm and less than or equal to 400 μm, and more preferably greater than or equal to 100 μm and less than or equal to 200 μm. The groove spacing p of the flow grooves 13 is the distance between the center lines of the groove widths of adjacent flow grooves 13. If the groove spacing p of the flow grooves 13 is greater than or equal to 40 μm, the flow grooves 13 can be easily formed. If the groove spacing p of the flow grooves 13 is less than or equal to 400 μm, the working fluid flows well in the internal space S, thereby improving the heat transfer characteristics of the heat spreader 1. In addition, it is preferred that the groove spacing p is greater than or equal to 50 μm and less than or equal to 100 μm greater than the groove width w. If the groove spacing p and the groove width w are in such a relationship, the flow grooves 13 can be easily formed. Furthermore, since the amount of working fluid per unit area in the flow channel grooves can be kept high, the working fluid is less likely to dry up, thereby improving the heat transfer performance of the vapor chamber 1 .

[0053] The groove width w of the bottom groove portion 14 constituting the flow path groove 13 is preferably 20 μm to 200 μm, more preferably 50 μm to 100 μm. The groove depth d and groove width w of the bottom groove portion 14 are preferably such that d / w is 2.0 to 20.0. If the groove width w and groove depth d of the bottom groove portion 14 are above the lower limit values, the bottom groove portion 14 can be easily formed. If the groove width w and groove depth d of the bottom groove portion 14 are below the upper limit values, the capillary action of the bottom groove portion 14 is more easily applied to the working fluid.

[0054] The groove width w of the side groove portion 15 is preferably 20 μm to 200 μm, more preferably 50 μm to 100 μm. The groove depth d and groove width w of the side groove portion 15 preferably have a ratio d / w of 2.0 to 20.0 μm. If the groove width w and groove depth d of the side groove portion 15 are above the lower limits, the side groove portion 15 can be easily formed. If the groove width w and groove depth d of the side groove portion 15 are below the upper limits, the capillary action of the side groove portion 15 is more easily acted upon by the working fluid.

[0055] The groove width w of the top surface groove portion 16 is preferably greater than or equal to 200 μm and less than or equal to 200 μm, more preferably greater than or equal to 50 μm and less than or equal to 100 μm. The groove depth d and groove width w of the top surface groove portion 16 are preferably such that d / w is greater than or equal to 2.0 and less than or equal to 20.0 μm. If the groove width w and groove depth d of the top surface groove portion 16 are greater than or equal to the above lower limits, the top surface groove portion 16 can be easily formed. If the groove width w and groove depth d of the top surface groove portion 16 are less than or equal to the above upper limits, the capillary effect of the top surface groove portion 16 is more easily acted upon by the working fluid.

[0056] Laser processing is preferred for forming the flow grooves 13 that improve the heat transfer characteristics of the vapor chamber 1, particularly the flow grooves 13 and side grooves 15 having the aforementioned specified groove width w, groove depth, and groove spacing p. Laser processing is particularly preferred. Laser processing allows the flow grooves 13, including the side grooves 15, to be formed into the desired shape in a short period of time. On the other hand, etching using an etching solution, as used in conventional vapor chambers, is difficult to control the shape of the flow grooves 13 and to form the side grooves 15, resulting in significantly lower processability compared to laser processing.

[0057] Furthermore, from the perspectives of high thermal conductivity and ease of processing using a laser, the materials constituting the first metal sheet 10 and the second metal sheet 20 are preferably copper, copper alloys, aluminum, aluminum alloys, or stainless steel. Among these, aluminum and aluminum alloys are more preferred for weight reduction, while stainless steel is more preferred for increased mechanical strength. Furthermore, depending on the usage environment, tin, tin alloys, titanium, titanium alloys, nickel, nickel alloys, and the like may also be used for the first metal sheet 10 and the second metal sheet 20.

[0058] In addition, if Figures 2 to 4 As shown, the ratio (t2 / t1) of the sheet thickness t2 at the protrusion 12 of the first metal sheet 10 to the sheet thickness t1 at the recessed flow path 11 of the first metal sheet 10 is preferably 0.1 to 10.0, more preferably 0.2 to 5.0, even more preferably 0.5 to 2.0, and most preferably 1.0, meaning that the sheet thickness t1 at the recessed flow path 11 is the same as the sheet thickness t2 at the protrusion 12. When the ratio (t2 / t1) is within this range, variations in the sheet thickness of the first metal sheet 10 are suppressed, thereby reducing the weight of the vapor chamber 1. The first metal sheet 10 having this predetermined ratio (t2 / t1) is preferably formed using a stamping process.

[0059] In addition, if Figure 1 As shown, the first metal sheet 10 preferably includes a plurality of flow grooves 13 and an intersection 17 where the plurality of flow grooves 13 intersect. Figure 1 The intersection 17 can be formed by the intersection of multiple bottom grooves 14, or by the intersection of multiple side grooves 15, or by the intersection of multiple bottom grooves 14 and multiple side grooves 15. Figure 1 As shown, the plurality of top surface grooves 16 intersect each other. An intersection 17 formed by the plurality of bottom surface grooves 14 is provided on the bottom surface 11a of the recessed flow path 11. An intersection 17 formed by the plurality of side surface grooves 15 is provided on the side surface 12b of the protrusion 12. An intersection 17 formed by the plurality of top surface grooves 16 is provided on the top surface 12a of the protrusion 12.

[0060] If the first metal sheet 10 has the intersections 17 , the capillary action of not only the flow grooves 13 but also the intersections 17 acts on the working fluid, further improving heat transfer within the internal space S. Therefore, the heat transfer characteristics of the vapor chamber 1 are further improved.

[0061] In addition, if Figure 1 and Figure 4As shown, if the heating element 30 is mounted on the outer surface 20b of the second metal sheet 20, the back of the heating element 30 on the inner surface 20a of the second metal sheet 20 becomes the condensation portion 42, and the liquid working fluid flows smoothly from the bottom groove 14 to the top groove 16 via the side groove 15. The circulation of the liquid and gaseous working fluids is further improved, thereby further improving the heat transfer characteristics of the heat spreader 1. The heating element 30 is a component such as an electronic component that generates heat during operation, such as a semiconductor element.

[0062] Furthermore, from the viewpoint of improving the heat transfer characteristics of the heat spreader 1 , it is preferable that the protrusion 12 including the top surface groove 16 is disposed at a position other than the evaporation portion 41 .

[0063] The heat spreader 1 cools the heat generating element 30 mainly through the following cooling paths.

[0064] First, the heat generated by the heating element 30, which is thermally connected to the outer surface 20b of the second metal sheet 20, is transferred to the evaporation portion 41 located on the inner surface 20a of the second metal sheet 20. The evaporation portion 41 uses the heat received from the heating element 30 to evaporate the liquid-phase working fluid flowing in the top surface groove 16, causing it to change phase into a gas-phase working fluid. The gas-phase working fluid heated by evaporation flows toward the condensation portion 42, located at a position separated from the evaporation portion 41, as shown by arrow F(G). As the gas-phase working fluid flows toward the condensation portion 42, the temperature of the working fluid decreases. In the condensation portion 42, the gas-phase working fluid, whose temperature has dropped, condenses and changes phase into a liquid-phase working fluid. The latent heat generated by the phase change is transferred to the first metal sheet 10 and the second metal sheet 20 and released to the outside of the heat spreader 1. The condensed liquid-phase working fluid flows smoothly in the in-plane direction of the heat spreader 1 along the bottom surface groove 14, as shown by arrow F(L). When the liquid working fluid flowing in bottom grooves 14 is transferred to side grooves 15, it flows smoothly along the side grooves 15 in the thickness direction of vapor chamber 1. The liquid working fluid flowing along the thickness direction of vapor chamber 1 returns to evaporation section 41 through top grooves 16. Through this smooth circulation of liquid and vapor working fluids, vapor chamber 1 can cool heating element 30.

[0065] Next, a method for manufacturing the above-mentioned heat spreader 1 will be described.

[0066] The manufacturing method of the heat spreader 1 includes a laser processing step of forming at least the side groove portion 15 in the flow path groove 13 of the first metal sheet 10 using a laser. In the laser processing step, it is preferable to use a fiber laser to form the side groove portion 15. In laser processing, it is easy to control the side groove portion 15 to the desired shape and form the side groove portion 15 in a short time. In addition, among lasers, the fiber laser is more excellent in processing control and short processing time. On the other hand, in the etching process using an etching solution used in conventional heat spreaders, the formation of the side groove portion 15 itself is difficult.

[0067] Furthermore, in the laser processing step, it is preferred to form the flow groove 13 using a laser. Specifically, it is preferred to form the bottom groove portion 14, the side groove portions 15, and the top groove portion 16 that constitute the flow groove 13 using a laser. Using a laser allows the flow groove 13, including the side groove portions 15, to be formed into the desired shape in a short period of time. On the other hand, conventional etching processes have made it difficult to control the processing of the flow groove 13, including the side groove portions 15, into the desired shape.

[0068] In addition, the method for manufacturing the heat spreader 1 preferably further includes a stamping step of forming the recessed flow paths 11 and the protruding portions 12 of the first metal sheet 10 by stamping before the laser processing step. By stamping the first metal sheet 10, the recessed flow paths 11 and the protruding portions 12 can be easily formed.

[0069] Furthermore, the method for manufacturing the heat spreader 1 preferably further comprises, after the laser processing step, a laser welding step of laser-welding the first metal sheet 10 and the second metal sheet 20. By laser-welding the first metal sheet 10 and the second metal sheet 20, the heat spreader 1 having the internal space S therein can be easily manufactured.

[0070] Specifically, the inner surface 10a of the first metal sheet 10 and the inner surface 20a of the second metal sheet 20, which are provided with the recessed flow paths 11, the protrusions 12, the flow grooves 13, etc., are positioned opposite each other, and a laser is irradiated onto the first metal sheet 10 and the second metal sheet 20, with the outer edge 10c of the first metal sheet 10 and the inner surface 20a of the second metal sheet 20 in contact. For example, the laser may be irradiated onto the contact portion between the first and second metal sheets 10, 20 from the side of the first metal sheet 10, from the side of the second metal sheet 20, or from the in-plane direction of the heat spreader 1. A combination of these laser irradiation methods may also be used.

[0071] Furthermore, the vapor chamber 1 is suitable for electronic devices such as mobile phones that require good heat transfer properties in various postures. Electronic devices equipped with the vapor chamber 1 can maintain the high heat transfer properties of the vapor chamber 1 in various usage conditions.

[0072] According to the above-described embodiment, the liquid-phase working fluid within the vapor chamber flows smoothly along the flow channels, even in the thickness direction of the vapor chamber. This reduces turbulence in the liquid-phase working fluid flow, improving the circulation of the liquid and gas-phase working fluids and increasing heat transfer within the vapor chamber. Consequently, the vapor chamber exhibits excellent heat transfer characteristics.

[0073] It should be noted that the above shows Figure 1 Although the example in which the heating element 30 is attached to the outer surface 20 b of the second metal sheet 20 is shown, the heating element 30 may be attached to the outer surface 10 b of the first metal sheet 10 .

[0074] In addition, while the above example shows a planar inner surface 20a of the second metal sheet 20, it is also possible that not only the first metal sheet 10 but also the inner surface 20a of the second metal sheet 20 has the bottom groove 14. If the second metal sheet 20 has the bottom groove 14, the heat transfer characteristics of the vapor chamber 1 are further improved.

[0075] In addition, while the above example illustrates a planar inner surface 20a of the second metal sheet 20, the inner surface 20a of the second metal sheet 20 may also have any configuration, such as a recessed flow path, at least one protrusion, and at least one flow groove, similar to the inner surface 10a of the first metal sheet 10. If the second metal sheet 20 has a recessed flow path, at least one protrusion, or at least one flow groove, the heat transfer characteristics of the vapor chamber 1 are further improved.

[0076] In addition, as shown above, Figure 1 The protrusion 12 shown is an example of a cylindrical shape, but the shape of the protrusion 12 can be any shape as long as the top surface 12a can abut against the inner surface 20a of the second metal sheet 20. For example, the shape of the protrusion 12 can also be as follows: Figure 5 Shown is a quadrangular prism.

[0077] In addition, as shown above, Figures 1 to 4 The example shown is an example in which the thickness uniformity of the first metal sheet 10 is high, but it is also possible to Figures 6-8As shown, the sheet thickness at the protrusion 12 of the first metal sheet 10 is significantly greater than the sheet thickness at the recessed flow path 11. In this case, the bottom groove 14 may also partially enter the protrusion 12, or preferably penetrate the protrusion 12 as shown. If the bottom groove 14 partially enters the protrusion 12 or penetrates the protrusion 12, the liquid working fluid flows more efficiently, thereby further improving the heat transfer characteristics of the vapor chamber 1.

[0078] While the embodiments have been described above, the present invention is not limited to the above embodiments, but includes all aspects encompassed by the concept of the present invention and the claims, and various modifications are possible within the scope of the present invention.

[0079] Description of Reference Numerals

[0080] 1 Vapor Chamber

[0081] 10. 1st Metal Sheet

[0082] 10a Inner surface of the first metal sheet

[0083] 10b Outer surface of the first metal sheet

[0084] 10c Outer edge of the first metal sheet

[0085] 11 Recessed flow path

[0086] 11a Bottom surface of the recessed flow path

[0087] 12 protrusion

[0088] 12a Top surface of the protrusion

[0089] 12b Side of the protrusion

[0090] 13 flow channel

[0091] 14 Bottom groove

[0092] 15 side groove

[0093] 16 Top surface groove

[0094] 17 intersection

[0095] 20 2nd metal sheet

[0096] 20a Inner surface of the second metal sheet

[0097] 20b Outer surface of the second metal sheet

[0098] 30 heating element

[0099] 41 Evaporation section

[0100] 42 Condensation section

[0101] S Interior Space

[0102] F(L) Flow of the liquid phase working fluid

[0103] F(G) Flow of the gas phase working fluid

Claims

1. A vapor chamber comprising a working fluid in an internal space formed between a first metal sheet and a second metal sheet, wherein: The first metal sheet comprises a concave flow path, at least one protrusion, and at least one flow path groove. The recessed flow path is provided on the inner surface of the first metal sheet. The protrusion protrudes from the inner surface of the first metal sheet toward the inner surface of the second metal sheet, and the top surface of the protrusion abuts against the inner surface of the second metal sheet. The flow path groove has a bottom groove portion, a side groove portion and a top groove portion, The bottom groove is provided on the bottom surface of the recessed flow path. The side groove is provided on the side of the protruding portion and is connected to the bottom groove. The top surface groove portion is provided on the top surface of the protruding portion and is connected to the side surface groove portion.

2. The vapor chamber according to claim 1, wherein: The groove depth d of the flow path groove is greater than the groove width w.

3. The vapor chamber according to claim 1 or 2, wherein: A ratio (t2 / t1) of a sheet thickness t2 of the first metal sheet at the protruding portion to a sheet thickness t1 of the first metal sheet at the recessed flow path is 0.1 or more and 10.0 or less.

4. The vapor chamber according to any one of claims 1 to 3, wherein The first metal sheet includes a plurality of the flow path grooves and has an intersection where the plurality of the flow path grooves intersect.

5. A method for manufacturing a vapor chamber, the method being the method for manufacturing a vapor chamber according to any one of claims 1 to 4, wherein the method is characterized in that: The method includes a laser processing step of forming at least the side groove portion of the flow path groove of the first metal sheet using a laser.

6. The method for manufacturing a vapor chamber according to claim 5, wherein: In the laser processing step, the flow channel groove is formed using laser.

7. The method for manufacturing a vapor chamber according to claim 5 or 6, wherein: Before the laser processing step, a press processing step of forming the recessed flow path and the protruding portion of the first metal sheet by press forming is further included.

8. The method for manufacturing a vapor chamber according to any one of claims 5 to 7, wherein: After the laser processing step, a laser welding step of welding the first metal sheet and the second metal sheet using a laser is further included.

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