Heat sink and heat sink manufacturing process

Abstract

A heat sink (1A, 1B, 1D, 1E, 1F, 1G, 1H, 1K) comprising:a main body (10A, 10B, 10D, 10F, 10G, 10H, 10K) in contact with at least one heat source (2A, 2F, 2G, 2H, 3G); and a plurality of flow paths (70) arranged within the main body (10A, 10B, 10D, 10F, 10G, 10H, 10K) and extending in a helical shape, wherein the plurality of flow paths (70) are configured to convey a coolant, the plurality of flow paths (70) being arranged such that central axes (C) of the helices are adjacent to one another, and each two adjacent flow paths (70) of the plurality of flow paths (70) are intertwined with one another, the central axes (C) of the helices of adjacent flow paths (70) of the plurality of flow paths (70) being adjacent to one another.

Description

Technical area

[0001] The present disclosure relates to a heat sink and a method of manufacturing the same. background

[0002] Some heat sinks are liquid-cooled, which uses coolant to cool main bodies that are in contact with heat sources to be cooled, thereby cooling the heat sources. Such liquid-cooled heat sinks are equipped with flow paths within the main body to transport the coolant.

[0003] For example, Patent Literature 1 discloses a heat sink provided with multiple helical flow paths within a main body.

[0004] Patent Literature 2 discloses a heat exchanger having a meandering first flow path and a meandering second flow path arranged in the meandering first flow path.

[0005] Patent Literature 3 discloses a heat exchanger in which a cold water pipe and a hot water pipe are intertwined.

[0006] Patent Literature 4 discloses a cooling device having alternately arranged first and second plates that generate a coolant flow rotating about an axis. Citation listPatent literature Patent literature 1: JP 2017- 69 518 A Patent literature 2: EP 2 677 260 A1 Patent Literature 3: CN 1 09 458 862 A Patent literature 4: US 2019 / 0 353 434 A1 Overview of the inventionTechnical problem

[0007] In a heat sink, the flow paths more easily dissipate heat to the coolant flowing in the flow paths as the areas of the inner walls of the flow paths increase. This means that the inner walls of the flow paths preferably have larger areas to improve heat dissipation efficiency.

[0008] Unfortunately, in the heat sink disclosed in Patent Literature 1, the central axes of the helical flow paths are arranged parallel to each other and away from each other. This structure makes it difficult to arrange the flow paths at a high density within the main body. Therefore, the structure cannot easily improve heat dissipation efficiency by increasing the areas of the inner walls of the flow paths.

[0009] An object of the present disclosure, made to solve the above problem, is to provide a heat sink having improved heat dissipation efficiency and a method of manufacturing the heat sink. Solution to the problem

[0010] To achieve the above object, a heat sink is proposed having the features defined in claim 1. Advantageous embodiments of the heat sink have the features defined in dependent claims 2 to 13. Furthermore, a method for manufacturing a heat sink is proposed, which has the features defined in pending claims 14 and 20. Advantageous embodiments of the method have the features defined in dependent claims 15 to 19. A heat sink according to one aspect of the present disclosure comprises: a main body in contact with at least one heat source; and a plurality of flow paths arranged within the main body, extending in a helical shape, and configured to convey coolant. The plurality of flow paths are arranged such that central axes of the helices are adjacent to each other.Two of the many flow paths, of which the central axes of the helices lie next to each other, are intertwined. Advantageous effect of the invention

[0011] According to one aspect of the present disclosure, the plurality of flow paths within the main body has a high density because any two of the plurality of flow paths, of which the central axes of the helices are adjacent, are intertwined. This structure increases the surface area of ​​the entire flow path. The heat sink accordingly has improved heat dissipation efficiency. Brief description of the drawings Fig. 1 is a perspective view of a heat sink according to Embodiment 1 of the present disclosure; Fig. 2A is a plan view of the heat sink according to Embodiment 1 of the present disclosure; Fig. 2B is a rear view of the heat sink according to Embodiment 1 of the present disclosure; Fig. 2C is a left side view of the heat sink according to Embodiment 1 of the present disclosure; Fig. 3 is a perspective view of an array of round tubes included in the heat sink according to Embodiment 1 of the present disclosure; Fig. 4A is a plan view of the arrangement of round tubes included in the heat sink according to Embodiment 1 of the present disclosure; Fig. 4B is a rear view of the arrangement of round tubes included in the heat sink according to Embodiment 1 of the present disclosure; Fig. 4C is a left side view of the arrangement of round tubes included in the heat sink according to Embodiment 1 of the present disclosure; Fig. 5A is a perspective view of a round tube taken out of the array of round tubes included in the heat sink according to Embodiment 1 of the present disclosure; Fig. 5B is an enlarged view of the left end of the round tube taken out of the array of round tubes included in the heat sink according to Embodiment 1 of the present disclosure; Fig. 6A is a plan view of round tubes taken out of the array of round tubes included in the heat sink according to Embodiment 1 of the present disclosure and arranged in the same order as in the heat sink; Fig. 6B is a left side view of the round tubes taken out of the array of round tubes included in the heat sink according to Embodiment 1 of the present disclosure and arranged in the same order as in the heat sink; Fig. 7 is an enlarged view of the left end of the round tube in the area VII of Fig. 6B; Fig. 8 is a conceptual diagram of the heat sink according to Embodiment 1 of the present disclosure while water flows in the heat sink; Fig. 9 is a conceptual diagram of a mold for inserting the mesh-like arrangement of round tubes by molding in a method of manufacturing the heat sink according to Embodiment 1 of the present disclosure; Fig. 10 is a rear view of a heat sink according to Embodiment 2 of the present disclosure; Fig. 11 is a cross-sectional view along the line XI-XI of Fig. 10; Fig. 12A is a perspective view of a round tube included in a heat sink according to Embodiment 3 of the present disclosure; Fig. Figure 12B is an enlarged view of area XIIB of Fig. 12A; Fig. 13A is a perspective view of the round tube included in the heat sink according to a modification of Embodiment 3 of the present disclosure; Fig. Figure 13B is an enlarged view of area XIIIB of Fig. 13A; Fig. 14 is a perspective view of a heat sink according to Embodiment 4 of the present disclosure; Fig. 15 shows a configuration of components of a heat sink according to Embodiment 5 of the present disclosure; Fig. 16 is an enlarged view of area XVI of Fig. 15; Fig. 17 is a perspective view of a heat sink according to Embodiment 6 of the present disclosure; Fig. 18 is a perspective view of a heat sink according to a modification of Embodiment 6 of the present disclosure; Fig. 19 is a left side view of a heat sink according to Embodiment 7 of the present disclosure; Fig. 20 is a perspective view of the heat sink according to Embodiment 7 of the present disclosure; Fig. 21A is a perspective view of an apparatus used in a method for manufacturing a heat sink according to Embodiment 8; Fig. Fig. 21B is a perspective view of the device when the device is moved along the line XXIB-XXIB of Fig. 21A is cut open; Fig. Figure 21C is a cross-sectional view of the device taken along line XXIC-XXIC of Fig. 21A; Fig. 22A is a perspective view of the jig used in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure when the jig holds a first round pipe; Fig. 22B is a perspective view of the jig used in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure when the jig holds a second round tube in addition to the first round tube; Fig. 22C is a perspective view of the jig used in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure after the second round tube is rotated on the jig to be intertwined with the left half of the first round tube; Fig. 22D is a perspective view of the jig used in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure after the second round tube is further rotated on the jig to be entwined with the entire first round tube; Fig. 22E is a perspective view of the jig used in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure after an array of round tubes is configured by intertwining a large number of round tubes on the jig; Fig. 23A is a perspective view of the first round tube to be held on the jig in a flow path forming step included in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure; Fig. 23B is a perspective view of the round tube after the second round tube is rotated such that the right end of the second round tube is intertwined with the left end of the first round tube in the flow path forming step included in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure; Fig. 23C is a perspective view of the round tube after the second round tube is further rotated to be intertwined with the left half of the first round tube in the flow path forming step included in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure; Fig. 23D is a perspective view of the round tube after the second round tube is further rotated to be entangled with the entire first round tube in the flow path forming step included in the method for manufacturing the heat sink according to Embodiment 8 of the present disclosure; Fig. 24A is a perspective view of a main body manufactured by inserting an array of round tubes into a metal material constituting the main body by molding in a method for manufacturing the heat sink according to Embodiment 9 of the present disclosure; Fig. Figure 24B is an enlarged view of area XXIVB of Fig. 24A; Fig. 25A is a perspective view of the main body after the array of round tubes has been removed by dissolving the array of round tubes in the method for manufacturing the heat sink according to Embodiment 9 of the present disclosure; and Fig. Figure 25B is an enlarged view of area XXVB of Fig. 25A. Description of embodiments

[0012] Hereinafter, a heat sink and a method of manufacturing the heat sink according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, components that are identical or corresponding to each other are denoted by the same reference numerals. In the XYZ orthogonal coordinate system shown in the drawings, a main body included in the heat sink is arranged so that the surface in contact with a heat source faces upward, coolant supply ports provided in the main body face to the left, and coolant outlet ports face to the right. In this coordinate system, the left-right direction corresponds to the X direction, the up-down direction corresponds to the Z direction, and the direction orthogonal to the Z and X axes corresponds to the Y axis. The following description refers to this coordinate system where appropriate. Embodiment 1

[0013] A heat sink according to Embodiment 1 is a liquid-cooled heat sink comprising a main body provided with flow paths for conveying coolant. In this heat sink, a network-like arrangement of round tubes made of a plurality of round tubes defines flow paths. The following description is first limited to an overall configuration of the heat sink with reference to the Fig. 1 and 2A to 2C. The description is then directed to a configuration of the net-like arrangement of round tubes with reference to the Fig. 3 to 7.

[0014] Fig. 1 is a perspective view of a heat sink 1A according to Embodiment 1 of the present disclosure. Fig. 2A to 2C are top view, front view and left side view of the heat sink 1A. The Fig. 1A and 2A to 2C show a main body 10A in translucent gray to highlight round tubes 20A therein to facilitate understanding.

[0015] As in Fig. 1, the heat sink 1A comprises the main body 10A to which a heat source 2A to be cooled is attached.

[0016] The heat source 2A is a power semiconductor device comprising a semiconductor chip made of, for example, Si, SiC, or GaN. As shown in the Fig. 1 and Fig. 2A, the heat source 2A has a shape of a rectangular flat plate when viewed from above. The heat source 2A accordingly has a flat lower surface 5, as shown in the Fig. 2B and Fig. 2C shown.

[0017] In order to accommodate this heat source 2A thereon, the main body 10A has a shape of a rectangular parallelepiped like a plate, as shown in the Fig. 1 and 2A to 2C. The main body 10A has an upper surface portion 11 that is larger than the lower surface 5 of the heat source 2A. The upper surface portion 11 is a flat surface and thus has a large contact area with the heat source 2A.

[0018] Attaching the heat source 2A to the upper surface portion 11 brings the lower surface 5 of the heat source 2A into contact with the upper surface portion 11. The heat from the heat source 2A is accordingly transferred to the main body 10A via the upper surface portion 11.

[0019] The main body 10A is made of a metal material, such as an aluminum alloy or a copper alloy, which has high thermal conductivity to transfer heat from the heat source 2A to the interior of the main body 10A. The main body 10A is a solid body made of this metal material. Accordingly, the main body 10A can transfer heat from the heat source 2A to the interior and entire area of ​​the main body 10A. The main body 10A then releases the heat transferred from the heat source 2A to the air in contact with the surfaces of the main body 10A. The main body 10A thereby cools the heat source 2A.

[0020] Since the main body 10A is made of the metal material and has a shape of a block, the main body 10A is also called a metal block or simply a block.

[0021] Unfortunately, the heat dissipation from the main body 10A may not achieve sufficient cooling of the heat source 2A. For example, in a case where the heat source 2A is a power semiconductor device with a miniaturized configuration, the heat source 2A easily reaches a high temperature due to the high density of circuitry within the device. In such a case, the main body 10A may not sufficiently cool the heat source 2A even after dissipating the heat to the air.

[0022] To solve this problem, the main body 10A is provided with a plurality of flow paths therein for carrying a coolant to improve heat dissipation performance.

[0023] In detail, a plurality of round tubes 20A extend in the main body 10A to improve the heat dissipation efficiency, as shown in Fig. 1. These round tubes 20A configure an array of round tubes 200A having multiple flow paths.

[0024] A configuration of the arrangement of round tubes 200A is shown below with reference to the Fig. 3 to 7.

[0025] Fig. Figure 3 is a perspective view of the arrangement of round tubes 200A included in the heat sink 1A. The Fig. 4A to 4C are top view, rear view and left side view of the 200A round tube assembly. Fig. 5A is a perspective view of a round tube 20A taken out from the array of round tubes 200A. Fig. 5B is an enlarged view of the left end of the round tube 20A. The Fig. 6A and Fig. 6B are top and left side views of the round tubes 20A arranged in the same order as in the heat sink 1A. Fig. 7 is an enlarged view of the left end of the round tube 20A in the area VII of Fig. 6B. The Fig. 5A and Fig. 5B show the round tube 20A when the Fig. 6A and Fig. 6B is cut in the middle to facilitate an understanding of an internal structure of the round tube 20A.

[0026] As in the Fig. 3 and 4A to 4C, the arrangement of round tubes 200A is made from the round tubes 20A which have a circular tube cross-section and are intertwined with each other.

[0027] Each of the round tubes 20A is made of a metal material having high thermal conductivity, like the main body 10A, to easily absorb heat from the main body 10A. As shown in Fig. As shown in Figure 5A, the round tube 20A extends in the left-right direction, specifically the X direction, while winding in a helical shape. In other words, the round tube 20A has a helix shape that curves clockwise around a central axis C toward the +X direction.

[0028] The clockwise direction indicates the clockwise direction as viewed from the -X side to the +X side. A helix indicates a three-dimensional curve that rotates around the direction perpendicular to the plane of rotation and translates in that direction. The concept of a helix encompasses a three-dimensional helix but excludes a two-dimensional spiral in this description. The round tube 20A is an example metal tube in this description.

[0029] As in Fig. As shown in Figure 5B, each of the round tubes 20A is a hollow tube. In other words, the round tube 20A has an interior space surrounded by the tube wall. The interior space of the round tube 20A is used to convey coolant and thus serves as a flow path.

[0030] Such round tubes 20A are arranged in the direction from front to back, as in Fig. 3. The round tubes 20A, which are adjacent to each other in the front-to-back direction, are intertwined with each other in such a way that the phases of the above-mentioned helices differ from each other.

[0031] In detail, the phases of the adjacent round tubes 20A are found to be deviated by almost 180 degrees when the Fig. 3 shown intertwined round tubes 20A are to be released and arranged in the original order in the direction from front to back, more precisely the Y-direction, as shown in the Fig. 6A and Fig. 6B. If the adjacent round tubes 20A are cut at a certain X-position by a plane parallel to the YZ plane, the positions of the adjacent round tubes 20A in this plane relative to the central axis C differ from each other, more precisely by almost 180 degrees. For example, the axis indicated by an arrow X1 in Fig. 6A, the position of a first round tube 20A, which is arranged furthest to the -Y end, is on the -Y side of the central axis C. In contrast, the corresponding position of a second round tube 20A, which is adjacent to the +Y side of the first round tube 20A and is arranged on this side, is on the +Y side of the central axis C. This fact means that the phases of the round tubes 20A, which are adjacent to each other in the Y direction, deviate from each other by almost 180 degrees.

[0032] As in Fig. As shown in Figure 7, each of the round tubes 20A is shaped to satisfy the following expression 1-1: 3φ1≤φ2 where φ1 indicates the outer diameter of the round tube 20A itself and φ2 indicates the outer diameter of the helix defined by the round tube 20A.

[0033] Due to this shape of the round tube 20A, the round tube 20A can be intertwined with another round tube 20A located adjacent to it in the Y-direction. The round tubes 20A are intertwined, but hardly interfere with each other. As shown in the Fig. 4A and Fig. As shown in Figure 4B, the round tubes 20A are intertwined with each other in the Y direction in each cycle of the helix.

[0034] In detail, the round tubes 20A are arranged so that their central axes C are parallel to each other, although this structure is not shown. The central axes C are spaced apart from each other at an interval equal to the difference between the outer diameter φ1 of the round tube 20A and the outer diameter φ2 of the helix, as shown in Fig. 7. As shown in Fig. As shown in Figure 6A, a front end portion F, which projects to the frontmost position, of a first round tube 20A is intertwined from the front side with a rear end portion B, which projects to the rearmost position, of a second round tube 20A, which is adjacent to and arranged on the front side of the first round tube 20A. A rear end portion B of the first round tube 20A is intertwined from the rear side with the front end portion F of a third round tube 20A, which is adjacent to and arranged on the rear side of the first round tube 20A. The round tubes 20A are thus intertwined with each other in each cycle of the helix. The round tubes 20A accordingly configure the net-like arrangement of round tubes 20A, as shown in Figures Fig. 4A to 4C shown.

[0035] The left and right ends of the round tubes 20A are open, as shown in the Fig. 3 and Fig. 4A. The left and right ends are connected to an external device (not shown) and thus serve as supply ports 21 for supplying coolant and discharge ports 22 for discharging the coolant, respectively. The circular tubes 20A accordingly function as flow paths for conveying the coolant.

[0036] The round tubes 20A extend in the left-right direction, as shown in the Fig. 3, Fig. 4A and Fig. 4B. The round tubes 20A thus conduct the aforementioned coolant from the supply ports 21 to the discharge ports 22. In addition, the round tubes 20A are intertwined with each other in the front-to-back direction, as described above. This structure increases the density of the round tubes 20A, or more precisely, the concentration of the flow paths, as viewed from the top of the main body 10A. This configuration can accordingly improve the efficiency of heat dissipation of the round tubes 20A from the main body 10A to the coolant.

[0037] As in the Fig. 4A to 4C and 7, the round tube 20A preferably satisfies the following expressions 2-1 and 2-2, assuming that φ1 indicates the outer diameter of each of the round tubes 20A, L indicates the length of the central axis of the above-mentioned helix, P indicates the pitch of the helix, and A indicates the amplitude of the helix: P=4φ1(σ+1) A=φ1(σ+1) where σ is a distance factor which is a measure of the minimum distance between round tubes 20A of which the central axes of the helices are adjacent to each other and satisfies the expression σ < 1, and t is an influence quantity and satisfies the expression 0 ≤ t≤ 1.

[0038] Furthermore, assuming that (i) the central axes of the helices extend in the X direction and are adjacent to each other in the Y direction and (ii) the X direction and the Y direction are orthogonal to the Z direction, the trajectory of the center of the n-th round tube 20A in the Y direction preferably satisfies the following expressions 2-3, 2-4 and 2-5 on the basis of radians: X=tL Y=Acos{360 / P+180(n−1)}+A(n−1) Z=Asin{360tL / P+180(n−1)}

[0039] In the case where the round tubes 20A satisfy expressions 2-1, 2-2, 2-3, 2-4, and 2-5, the round tubes 20A are intertwined so that imaginary round tubes 20A having a helical shape, the outer diameter of which is (σ+1) times the outer diameter of the round tubes 20A, do not overlap and are in contact with each other. In other words, the round tubes 20A are intertwined in the tightest manner so that the minimum distance, or more precisely, the interval, between the adjacent round tubes 20A is φ1σ. This structure allows the round tube 20A to define the densest flow paths and thus increase the heat dissipation area of ​​the main body 10A per unit volume. The heat sink 1A accordingly exhibits improved heat dissipation performance. Accordingly, the round tubes 20A preferably satisfy expressions 2-1, 2-2, 2-3, 2-4 and 2-5 as described above.

[0040] The above-mentioned interval φ1σ is preferably determined depending on various conditions such as the material constituting the main body 10A, the minimum thickness defined by the manufacturing method, and a heat diffusion level in the main body 10A.

[0041] In the following, functions of the heat sink 1A are described with reference to Fig. 8. The following description assumes that the heat source 2A, which is a power semiconductor device, is supplied with electrical power and dissipates heat. The description also assumes that the above-mentioned supply ports 21 are supplied with water as a coolant from the external device, which is not shown. This water is drained from the drain ports 22 and returns to the external device, which is not shown.

[0042] Fig. Figure 8 is a conceptual diagram of the heat sink 1A while water flows in the heat sink 1A.

[0043] When the heat source 2A radiates heat, this heat is transferred to the main body 10A as shown by the arrows A1 in Fig. 8. The heat is transferred to the interior and the entire area of ​​the main body 10A because the metal material of the main body 10A has high thermal conductivity.

[0044] The main body 10A includes the round tubes 20A extending therein. The round tubes 20A convey the aforementioned water.

[0045] Since each of the round tubes 20A has a helical shape winding in the up-down and front-back directions, the water flows along a helical path as shown by the arrows A2 in Fig. 8. The water therefore receives centrifugal forces toward the radial directions of the helix. The centrifugal forces increase the flow rate of the water near the inner wall of the round tube 20A in the radial directions of the helix. This phenomenon reduces the thickness of a temperature boundary layer. The temperature boundary layer indicates a layer where the temperature of the water changes significantly from the inner wall of the round tube 20A toward the center of the round tube 20A. Accordingly, the heat reaching the inner wall of the round tube 20A is easily transferred to the water, resulting in increased thermal conductivity from the main body 10A to the water.

[0046] The water flows through each of the helical-shaped round tubes 20A. The inner wall of the round tube 20A has a contact area with the water that is larger than that of a linearly extending round tube. This configuration allows the water to absorb a larger amount of heat transferred from the heat source 2A to the main body 10A. In other words, the water absorbs a larger amount of heat due to the larger heat dissipation area from the inner wall of the round tube 20A. The heat transferred from the heat source 2A to the main body 10A is thus easily dissipated into the water.

[0047] The plurality of circular tubes 20A are arranged and intertwined throughout the main body 10A in the front-to-back direction. The circular tubes 20A are thus concentrated in the front-to-back direction. The water flowing through the circular tubes 20A accordingly absorbs heat from the entire main body 10A in the front-to-back direction. The water also absorbs heat from the entire main body 10A in the left-to-right direction because the circular tubes 20A extend in the left-to-right direction. Specifically, the water absorbs heat transferred to the entire area of ​​the main body 10A.

[0048] After absorbing the heat from the main body 10A, the water is drained from the above-mentioned drain ports 22. The water thereby releases the heat from the main body 10A to the outside, resulting in cooling of the heat source 2A.

[0049] As described above, the main body 10A in the heat sink 1A has high thermal conductivity to the water and thus easily dissipates heat from the main body 10A to the water. Furthermore, the water absorbs heat from the entire main body 10A. Accordingly, the heat sink 1A has improved heat dissipation performance, specifically, a high cooling capacity of the heat source 2A.

[0050] In the following, a method for manufacturing the heat sink 1A will be described with reference to Fig. 9 described.

[0051] Fig. 9 is a conceptual diagram of a mold 90 for inserting the mesh-like arrangements of round tubes 200A by molding in the process of manufacturing the heat sink 1A.

[0052] First, several round tubes 20A are prepared, which have a helical shape, which is inserted into the Fig. 6A and Fig. 6B. The round tubes 20A are made of a metal material having a melting point greater than or equal to that of the metal material of a molten metal described below.

[0053] The prepared round tubes 20A are then arranged in the positional relationship described above. This process results in a network-like arrangement of round tubes 200A, which are inserted into the Fig. 4A to 4C.

[0054] This step of preparing a plurality of round tubes 20A and forming a mesh-like arrangement of round tubes 200A from the round tubes 20A is an exemplary flow path formation step in this specification. This step is also referred to as the flow path formation step in this specification.

[0055] The resulting net-like arrangement of round tubes 200A is then placed in the mold 90 as shown in Fig. 9 shown.

[0056] In detail, the mold 90 includes a plate 91 having a recess 911 on the lower surface forming the upper bottom, and a plate 92 having a recess 921 on the upper surface forming the lower bottom. The plate 91 can be stacked on the plate 92. While the plate 91 is stacked on the plate 92, the recesses 911 and 921 define a cavity having a rectangular parallelepiped shape like a plate and having dimensions identical to those of the main body 10A described above.

[0057] The meshed arrangement of round tubes 200A is inserted into the cavity defined by the recesses 911 and 921 by first placing the meshed arrangement of round tubes 200A in the recess 921 of the plate 92 and then stacking the plate 91 onto the plate 92. During the stacking of the plates 91 and 92, the openings of the round tubes 20A included in the meshed arrangement of round tubes 200A at the left and right ends are sealed with cores 93 and 94.

[0058] The cavity defined by the recesses 911 and 921 in the mold 90 is then filled with a molten material and this molten material is allowed to solidify.

[0059] In detail, a molten material is prepared by melting the above-mentioned metal material, such as an aluminum alloy or copper alloy, which has high thermal conductivity. The resulting molten metal is introduced into the casting mold 90 through a casting hole 95. The cavity in the casting mold 90 is thus filled with the molten metal.

[0060] The metal material of this molten metal preferably has a melting point lower than that of the metal material constituting the round tubes 20A in order to prevent melting of the round tubes 20A.

[0061] The casting mold 90 is then cooled, allowing the molten metal to solidify within the casting mold. The mesh-like arrangement of round tubes 200A is then embedded in the metal material of the molten metal by casting. This process results in a heat sink 1A comprising a main body 10A in which the mesh-like arrangement of round tubes 200A extends.

[0062] The metal material constituting the molten metal is an exemplary first metal material in this description. The metal material constituting the round tubes 20A is an exemplary second metal material in this description. The step of inserting the mesh-like arrangement of round tubes 200A into the metal material by casting is an exemplary step of inserting a plurality of tubes into the first metal material by casting in this description.

[0063] The plate 91 is then removed from the plate 92 at the mold 90 to remove the resulting heat sink 1A from the recess 921. The cores 93 and 94 are also removed from the openings of the round tubes 20A at the left and right ends. Then, a heat source 2A is attached to a plate surface of the main body 10A. This process completes the heat sink 1A, which is capable of cooling the heat source 2A.

[0064] The above-described step of preparing a plurality of round tubes 20A and the result of a mesh-like arrangement of round tubes 200A from the round tubes 20A may also be a step of forming the mesh-like arrangement of round tubes 200A with an additive manufacturing device, in particular, for example, with a 3D printer, although this alternative step requires additional time.

[0065] Alternatively, the net-like arrangement of round tubes 200A may be prepared by a lost wax casting process, although this alternative step cannot easily achieve production of a round tube 20A having a small diameter.

[0066] As described above, the heat sink 1A according to Embodiment 1 includes the mesh-like arrangement of round tubes 200A made of the round tubes 20A having a helical shape and intertwined with each other. This structure allows a coolant flowing in the round tubes 20A to easily absorb heat. The heat sink 1A accordingly has improved heat dissipation efficiency.

[0067] In the round tubes 20A, the central axes C of the helices are adjacent and parallel to each other. The adjacent round tubes 20A are intertwined with each other in each cycle of the helix. Such a dense arrangement of the round tubes 20A increases the heat dissipation efficiency of the heat sink 1A. Embodiment 2

[0068] In the heat sink 1A according to Embodiment 1, the metal material constituting the main body 10A and the metal material constituting the round tubes 20A have identical or different melting points. Specifically, the main body 10A and the round tubes 20A in the heat sink 1A may be different metal materials. In contrast, a heat sink 1B according to Embodiment 2 is characterized in that the metal material constituting a main body 10B is different from the metal material constituting the round tubes 20B. To prevent corrosion due to a combination of different metal materials, the round tubes 20B are plated.

[0069] The heat sink 1B according to Embodiment 2 will be described below with reference to the Fig. 10 and Fig. 11. The description of Embodiment 2 focuses primarily on the differences from Embodiment 1.

[0070] Fig. 10 is a rear view of the heat sink 1B according to Embodiment 2. Fig. 11 is a cross-sectional view along the line XI-XI of Fig. 10. In Fig. In Figure 11, only the round tubes 20B are represented by hatching to facilitate understanding. The dotted lines represent the outer circumference OC and the inner circumference IC of the round tube 20B, which winds in a helical shape.

[0071] In the heat sink 1B, the main body 10B includes supply flow paths 31 and discharge flow paths 32, as shown in Fig. 10 shown.

[0072] Each of the supply flow paths 31 extends from a left surface part 12 toward the interior of the main body 10B and leads to the left end of the round tube 20B. The supply flow path 31 is connected to the coolant pipe included in the external device and thereby guides coolant supplied from the coolant pipe to the round tube 20B.

[0073] Each of the drain flow paths 32 extends from a right surface part 13 toward the interior of the main body 10B and leads to the right end of the round tube 20B. The drain flow path 32 is connected to the coolant pipe included in the external device, thereby draining the coolant in the round tube 20B to the coolant pipe.

[0074] The main body 10B is made of an aluminum alloy. In contrast, the round tubes 20B are made of an iron and steel material. When coolant is supplied to the heat sink 1B, this coolant comes into contact with the aluminum alloy constituting the inner walls of the supply flow paths 31 and the discharge flow paths 32 included in the main body 10B, and also comes into contact with the iron and steel material constituting the inner walls of the round tubes 20B. The aluminum contained in the aluminum alloy and the iron contained in the iron and steel material have significantly different ionization tendencies. This characteristic causes potential differences between the supply flow paths 31 and the inner walls of the round tubes 20B, and between the discharge flow paths 32 and the inner walls of the round tubes 20B, so that flow flows therebetween.These flow flows can result in corrosion in the supply flow paths 31, the discharge flow paths 32 and the inner walls of the round pipes 20B.

[0075] To solve this problem, the inner wall of each round tube 20B is plated as shown in Fig. 11. In detail, the inner wall of the round tube 20B is covered with a coating 23.

[0076] The coating 23 is made of zinc. The zinc has an ionization tendency closer to that of the aluminum constituting the main body 10B than to that of the iron constituting the round tube 20B. In detail, the iron constituting the round tube 20B has a higher ionization tendency than that of the aluminum constituting the main body 10B. The zinc constituting the coating 23 has an ionization tendency higher than that of the aluminum constituting the main body 10B and lower than that of the iron constituting the round tube 20B. The ionization tendency of the zinc constituting the coating 23 is accordingly closer to that of the aluminum constituting the main body 10B than that of the iron constituting the round tube 20B.The coating 23 having this feature prevents corrosion by reducing the potential difference between the round tube 20B and the supply flow path 31 or the discharge flow path 32 in the main body 10B while the coolant flows.

[0077] The following description is directed to a method for manufacturing the heat sink 1B.

[0078] After preparing the round tubes 20B having a helical shape as described in Embodiment 1, the inner walls of these round tubes 20B are plated with zinc by a process such as electroplating, hot-dip galvanizing, or deposition plating. The plated round tubes 20B are then intertwined to form a mesh-like arrangement of round tubes 200B.

[0079] The zinc to be plated on the inner walls of the round tubes 20B is an exemplary third metal material in this description. The step of plating the inner walls of the round tubes 20B with zinc is an exemplary step of plating the inner walls of tubes with a third metal material in this description.

[0080] After preparing the meshed arrangement of round tubes 200B, this meshed arrangement of round tubes 200B is inserted into an aluminum alloy by casting, as in Embodiment 1. This process manufactures the heat sink 1B, which includes the main body 10B in which the meshed arrangement of round tubes 200B extends.

[0081] Then, a heat source 2A is attached to a plate surface of the main body 10B. This process completes the heat sink 1B, which is capable of cooling the heat source 2A.

[0082] Although the aforementioned coating 23 is made of zinc, the material constituting the coating 23 only needs to have an ionization tendency closer to that of the material constituting the main body 10B than that of the material constituting the round tube 20B. Thus, the coating 23 can be made of chromium, for example. In the case where the main body 10B is made of a copper alloy and the round tubes 20B are made of an aluminum alloy, the coating 23 can be made of titanium.

[0083] Although the above-mentioned plating is applied to the inner walls of the round tubes 20B, the plating can also be applied to the outer walls of the round tubes 20B.

[0084] As described above, in the heat sink 1B according to Embodiment 2, the coating 23 is made of zinc, which has an ionization tendency closer to that of aluminum constituting the main body 10B than to that of iron constituting the round tubes 20B. The inner walls of the round tubes 20B are covered with the coating 23. This configuration can make the heat sink 1B less susceptible to corrosion despite the coolant flowing in the round tubes 20B. Embodiment 3

[0085] In the heat sinks 1A and 1B according to Embodiments 1 and 2, the inner walls of the round tubes 20A and 20B have circular tube cross-sections and smooth surfaces. However, these heat sinks 1A and 1B are merely examples. In a heat sink according to Embodiment 3, the inner wall of each of the round tubes 20C has protrusions 24.

[0086] In the following, the heat sink according to embodiment 3 is described with reference to the Fig. 12A, Fig. 12B, Fig. 13A and Fig. 13B. The description of Embodiment 3 will mainly focus on the differences from Embodiments 1 and 2.

[0087] Fig. 12A is a perspective view of the round tube 20C included in the heat sink according to Embodiment 3. Fig. Figure 12B is an enlarged view of area XIIB of Fig. 12A. Fig. 13A is a perspective view of the round tube 20C according to a modification. Fig. Figure 13B is an enlarged view of area XIIIB of Fig. 13A. These figures show the round tube 20C when the round tube 20C enclosed in the heat sink is cut open in the middle to facilitate understanding.

[0088] As in the Fig. 12A and Fig. As shown in Fig. 12B, the inner wall of the round tube 20C has the rectangular projections 24, the longitudinal directions of which are aligned with the radial directions of the round tube in the cross-sectional view.

[0089] The projections 24 extend in the direction in which the round tube 20C extends while maintaining the above-mentioned cross-sectional shape. The round tube 20C extends in a helical shape, like the round tubes 20A and 20B described in Embodiments 1 and 2. The projections 24 therefore have a helical shape, although this configuration is not shown.

[0090] The protrusions 24 extend in the direction in which the round tube 20C extends, as described above. The protrusions 24 therefore extend in the direction in which the coolant flows through the round tube 20C when the coolant is supplied to the round tube 20C. The protrusions 24 thus disrupt the flow of the coolant in the circumferential direction within the round tube 20C and stir the coolant. The protrusions 24 accordingly improve the heat dissipation performance of the round tube 20C. Furthermore, the protrusions 24 expand the surface area of ​​the inner wall of the round tube 20C, thereby improving the heat dissipation performance of the round tube 20C.

[0091] Each of the protrusions 24 has sharp edges, which have a rectangular shape in cross-section. Specifically, the edges of the distal end of the protrusion 24, which is adjacent to the tube center, are not rounded and have a right angle in cross-sectional view. The protrusion 24 thus prevents the development of the temperature boundary layer mentioned in Embodiment 1. Accordingly, the protrusion 24 enables easy transfer of the heat transferred to the inner wall of the round tube 20C to the coolant.

[0092] A method for manufacturing the heat sink according to Embodiment 3 is identical to the method according to the above embodiments, except that the method includes providing the protrusions 24 in the round tube 20C. Therefore, the method for manufacturing the heat sink is not redundantly described in Embodiment 3.

[0093] The edges of the board 24 described above may also be rounded, as shown in the Fig. 13A and Fig. 13B. In detail, the edges of the board 24 can be processed to have a rounded edge and define a curved contour in the cross-sectional view. In this case, the board 24 can prevent the generation of a vortex near the edges while the coolant flows through the round tube 20C. The board 24 can accordingly reduce the pressure drop of the coolant.

[0094] The protrusions 24 may also extend in the direction perpendicular to the central axis C of the helix, provided that the protrusions 24 can stir the coolant. Alternatively, the protrusions 24 may extend in the direction in which the round tube 20C extends while meandering in the circumferential direction of the inner wall of the round tube 20C.

[0095] In the heat sink according to Embodiment 3 as described above, the protrusions 24 provided in the round tube 20C stir the coolant while the coolant flows through the round tube 20C. This structure improves the heat dissipation performance of the round tube 20C. The heat sink accordingly has improved heat dissipation efficiency. Embodiment 4

[0096] In the heat sinks 1A and 1B according to Embodiments 1 and 2, the left and right ends of the round tubes 20A and 20B are open at the left surface portion 12 and the right surface portion 13 of the main bodies 10A and 10B, respectively, and serve as the supply ports 21 and the discharge ports 22 for the coolant. However, these heat sinks 1A and 1B are merely examples. The heat sinks 1A and 1B may be provided with headers for distributing and collecting the coolant. A heat sink 1D according to Embodiment 4 includes headers.

[0097] Hereinafter, the heat sink 1D according to Embodiment 4 will be described with reference to Fig. 14. The description of Embodiment 4 will mainly focus on the differences from Embodiments 1 to 3.

[0098] Fig. 14 is a perspective view of the heat sink 1D according to Embodiment 4. Fig. 14 shows a main body 10D in translucent gray to highlight an arrangement of round tubes 200D therein to facilitate understanding.

[0099] As in Fig. 14, the heat sink 1D includes an inlet header 41 that connects the supply ports 21 included in the respective round tubes 20D, and an outlet header 42 that connects the drain ports 22 included in the respective round tubes 20D.

[0100] The inlet header 41 has a hollow cylindrical shape and extends through the main body 10D in the front-to-rear direction. The rear end of the inlet header 41 is sealed, although this configuration is not shown. The front end of the inlet header 41 is press-fitted with an inlet pipe 43. The inlet pipe 43 is connected to the external device and supplies the coolant.

[0101] The shaft of the cylinder defined by the inlet header 41 is orthogonal to the shafts of the cylinders defined by the round tubes 20D. The inner periphery of the inlet header 41 has openings leading to the supply ports 21 included in the respective round tubes 20D. More specifically, the space within the inlet header 41 communicates with the supply ports 21. The inlet header 41 with this structure distributes the coolant to the individual supply ports 21 of the round tubes 20D when the coolant is supplied from the inlet pipe 43.

[0102] The outlet header 42 also has a hollow cylindrical shape and extends through the main body 10D in the front-to-back direction, like the inlet header 41. The rear end of the outlet header 42 is sealed, like that of the inlet header 41. The front end of the outlet header 42 is press-fitted with an outlet pipe 44. The outlet pipe 44 is connected to the external device and discharges the coolant.

[0103] The shaft of the cylinder defined by the outlet header 42 is orthogonal to the shafts of the cylinders defined by the round tubes 20D. The inner periphery of the outlet header 42 has openings leading to the drain ports 22 contained within the respective round tubes 20D. More specifically, the space within the outlet header 42 communicates with the drain ports 22. The outlet header 42 with this structure collects the coolant discharged from the individual drain ports 22 as the coolant flows through the round tubes 20D.

[0104] The inlet header 41 is an exemplary first header in this description. The outlet header 42 is an exemplary second header in this description.

[0105] A method for manufacturing the heat sink 1D according to Embodiment 4 is identical to that of Embodiment 1, except that: (1) the left-right length of the main body 10D is longer than that of the round tubes 20D; (2) the inlet header 41 and the outlet header 42 are disposed near the left and right ends of the main body 10D, respectively; and (3) the inlet pipe 43 and the outlet pipe 44 are press-fitted into the inlet header 41 and the outlet header 42, respectively. Therefore, the method for manufacturing the heat sink 1D will not be redundantly described in Embodiment 4.

[0106] The inlet header 41 and the outlet header 42 can be manufactured using cores having hollow cylindrical shapes while inserting the net-like arrangement of round tubes 200D into the metal material by casting.

[0107] Although the inlet pipe 43 and the outlet pipe 44 are press-fitted into the inlet header 41 and the outlet header 42 in the heat sink 1D, the inlet pipe 43 and the outlet pipe 44 may be connected to the inlet header 41 and the outlet header 42 by other means. For example, the inlet pipe 43 and the outlet pipe 44 may have external threads, and the inlet header 41 and the outlet header 42 may have internal threads. The inlet pipe 43 and the outlet pipe 44 may be connected to the inlet header 41 and the outlet header 42 by fitting the external threads of the inlet pipe 43 and the outlet pipe 44 into the internal threads of the inlet header 41 and the outlet header 42, respectively.

[0108] As described above, the heat sink 1D according to Embodiment 4 includes the inlet header 41 and the outlet header 42 in the main body 10D and can accordingly easily supply and discharge the coolant.

[0109] The inlet header 41 and the outlet header 42 are cavities formed in the main body 10D and are integrated into the main body 10D. The heat sink 1D therefore has a simple structure. Embodiment 5

[0110] In Embodiment 1, the heat sink 1A is manufactured by inserting the mesh-like arrangement of round tubes 200A into the metal material by molding. However, this method of manufacturing the heat sink 1A is merely an example. A heat sink 1E according to Embodiment 5 is manufactured by stacking plate-like elements.

[0111] In the following, the heat sink 1E according to Embodiment 5 will be described with reference to the Fig. 15 and Fig. 16. The description of Embodiment 5 is mainly directed to the differences from Embodiments 1 to 4.

[0112] Fig. 15 shows a configuration of the components of the heat sink 1E according to Embodiment 5. Fig. 16 is an enlarged view of area XVI of Fig. 15. Fig. 15 shows the heat sink 1E when only some of a plurality of plate-like elements 50 constituting the heat sink 1E are disassembled and removed to facilitate understanding.

[0113] As in Fig. 15, the heat sink 1E is manufactured by stacking a large number of plate-like elements 50.

[0114] The plate-like members 50 are made of a metal material, such as an aluminum alloy or a copper alloy, which has high thermal conductivity, like the main body 10A described in Embodiment 1. The plate-like members 50 each have a rectangular plate surface having a shape identical to that of the cross-section of the main body 10A described in Embodiment 1 perpendicular to the left-right direction. The plate-like members 50 are arranged so that the longitudinal direction of the plate surfaces is oriented in the front-to-back direction and the lateral direction is oriented in the up-down direction.

[0115] The plate-like elements 50 have a thickness equal to the value calculated by dividing the length in the left-right direction of the main body 10A described in Embodiment 1 by a relatively large integer. Such plate-like elements 50 are stacked together in the left-right direction to configure a layered body 500. The layered body 500, made of the above-mentioned integer number of plate-like elements 50 stacked together, has the dimension in the left-right direction identical to that of the main body 10A described in Embodiment 1. The plate-like elements 50 have the shape identical to that of the cross section of the main body 10A perpendicular to the left-right direction, as described above.The laminated body 500, which is made by the above-mentioned integer number of plate-like members 50 stacked together, therefore has the same contour as that of the main body 10A described in Embodiment 1.

[0116] The plate-like elements 50 are each provided with a plurality of through holes 51 on the plate surface, which define openings with flattened shapes.

[0117] The number of through-holes 51 is identical to the number of round tubes 20A described in Embodiment 1. The openings defined by the through-holes 51 have flattened shapes. The through-holes 51 extend through each of the plate-like members 50 in the direction perpendicular to the plate surface. The through-holes 51 in one plate-like member 50 define openings whose orientations and positions differ from those of the through-holes 51 in another plate member 50 adjacent to the one plate-like member 50 in the left-right direction.

[0118] The deviations in the orientations and positions of the openings are described in detail below. When the plate-like elements 50 are stacked in the left-right direction, the centers of the through-holes 51 included in the adjacent plate-like elements 50 are arranged in the positions defining the helix described in Embodiment 1. The positions of the through-holes 51 therefore deviate from each other as described above.

[0119] The lateral directions of the openings defined by the through-holes 51 are directed toward the center of the helix. Since the centers of the through-holes 51 included in the adjacent plate-like elements 50 are arranged in the positions defining the above-described helix, the orientations of the openings defined by the through-holes 51 therefore differ from each other between the adjacent plate-like elements 50.

[0120] The openings defined by the through-holes 51 have orientations and positions that differ from each other, as described above. In the laminated body 500 formed by the plate-like members 50 stacked in the left-right direction, the entire arrays of the through-holes 51 respectively define holes having a helical shape, like the round tubes 20A described in Embodiment 1.

[0121] These holes, which have a helical shape, are supplied with coolant. The individual through holes 51 therefore serve as flow paths for the coolant.

[0122] Each of the holes, which has a helical shape, is defined by an arrangement of through-holes 51 that is orthogonal to the plate surfaces of the plate-like elements 50. This configuration has steps between the through-holes 51. The hole, which has a helical shape, thus has an uneven inner wall, and these steps stir the coolant as the coolant flows through the hole. This configuration improves the heat dissipation performance of the hole, which has a helical shape. The heat sink 1E therefore has improved heat dissipation efficiency.

[0123] The following description is directed to a method of manufacturing the heat sink 1E according to Embodiment 5.

[0124] First, plate-like elements 50 made of the above-mentioned material and having the above-mentioned shape are prepared. The plate-like elements 50 are then provided with through holes 51 having the above-mentioned shape. The number of through holes 51 is identical to the number of round tubes 20A described in Embodiment 1.

[0125] When forming the through-holes 51, the positions and orientations of the through-holes 51 are varied depending on where the plate-like member 50 is located in the above-mentioned laminated body 500. The through-holes 51 are preferably formed by a method such as laser processing, etching, or cutting. Alternatively, the through-holes 51 may be formed with the plate-like member 50 by press processing.

[0126] The through holes 51 may be made continuous in the case where the part between the through holes 51 has insufficient strength due to the excessively short distance between the through holes 51.

[0127] The step of forming the above-described through-holes 51 and manufacturing the plate-like members 50 having the through-holes 51 is an exemplary step of manufacturing plate-like members in this specification.

[0128] The plate-like elements 50, which are provided with the through-holes 51, are stacked and then bonded together. For example, the stacked plate-like elements 50 are bonded together by a method such as soldering, diffusion bonding, or compression. This process results in the heat sink 1E in which multiple flow paths are intertwined in a helical shape.

[0129] The step of stacking and connecting the plate-like elements 50 to and from each other is an exemplary step of configuring a block in this specification. The layered body 500 produced by stacking the plate-like elements 50 is an exemplary block in this specification.

[0130] A heat source 2A is then attached to a surface of the laminated body 500 that corresponds to the end surfaces of the plate-like elements 50, although this configuration is not shown. This process completes the heat sink 1E, which is capable of cooling the heat source 2A.

[0131] Although the above-described through-holes 51 extend in the direction perpendicular to the plate surface of the plate-like members 50, the through-holes 51 may also extend in a direction diagonal to the plate surfaces of the plate-like members 50.

[0132] Although the above-described through-holes 51 extend linearly in the thickness direction of the plate-like elements 50, the through-holes 51 may also extend in the thickness direction while winding. Specifically, the above-mentioned holes, which have a helical shape, may have smooth inner walls without the above-mentioned steps between the adjacent plate-like elements 50 in the layered body 500.

[0133] As described above, the heat sink 1E according to Embodiment 5 can be easily manufactured by simply stacking the plate-like members 50 having the through-holes 51.

[0134] For example, Embodiment 1, in which the flow paths of the heat sink 1A are defined by the mesh-like arrangement of round tubes 200A, is not suitable for easily manufacturing the flow paths having small structures. In contrast, such flow paths having small structures can be easily manufactured in Embodiment 5, in which the flow paths are defined by the through-holes 51 provided in the plate-like members 50. Embodiment 6

[0135] In Embodiments 1 to 5, each of the main bodies 10A, 10B, and 10D has the flat upper surface portion 11. Specifically, the surface to which the heat source 2A is attached is flat. However, these shapes of the main bodies 10A, 10B, and 10D are merely examples. The main bodies 10A, 10B, and 10D may also have a surface adapted to the heat sources 2A to be attached. A heat sink 1F according to Embodiment 6 includes a curved main body 10F.

[0136] Hereinafter, the heat sink 1F according to Embodiment 6 will be described with reference to Fig. 17. The description of Embodiment 6 is mainly directed to the differences from Embodiments 1 to 5.

[0137] Fig. 17 is a perspective view of the heat sink 1F according to Embodiment 6. Fig. 17 shows the main body 10F in translucent gray to highlight an arrangement of round tubes 200F therein to facilitate understanding.

[0138] As in Fig. 17, the heat sink 1F configured to cool a heat source 2F having a shape of a plate curved in the longitudinal direction, more specifically, the front-to-back direction, includes the main body 10F curved in the same direction.

[0139] The main body 10F has a plate shape that is larger than that of the heat source 2F and is curved in the front-to-back direction. The main body 10F includes the arrangement of round tubes 200F located therein, which is curved in the same direction as the main body 10F.

[0140] The round tube array 200F is made of a combination of multiple round tubes 20F having a shape identical to that of the round tubes 20A described in Embodiment 1. In the round tube array 200F, the round tubes 20F are arranged so that the central axes C of the helices are aligned in the lateral direction of the plate surface of the main body 10F, specifically, the X direction. These round tubes 20F are adjacent to each other in the Y direction, and adjacent round tubes 20F are intertwined.

[0141] The interlacing mode of the round tubes 20F is identical to that in Embodiment 1, except that adjacent round tubes 20F are offset from each other in the Z direction. With respect to the +Y direction from the round tube 20F at the -Y end to the center in the Y direction of the main body 10F, in the arrangement of round tubes 200F, a second round tube 20F, which is adjacent to and arranged on the +Y side of a first round tube 20F, is arranged from the first round tube 20F in the -Z direction. With respect to the +Y direction from the center in the Y direction of the main body 10F to the round tube 20F at the +Y end, a fourth round tube 20F, which is adjacent to and arranged on the +Y side of a third round tube 20F, is arranged from the third round tube 20F in the +Z direction. Thus, the arrangement of round tubes 20F has a mesh shape that extends linearly in the X direction and is curved in the Y direction.Accordingly, the array of round tubes 200F within the main body 10F is curved along the upper surface portion 11 of the main body 10F, to which the heat source 2F is attached. This structure enables effective heat transfer from the heat source 2F to the array of round tubes 200F. The heat source 2F is accordingly cooled with high efficiency.

[0142] As described above, in the heat sink 1F according to Embodiment 6, the main body 10F has a surface curved along the shape of the heat source 2F to be mounted, and the array of round tubes 200F is curved along this surface. This structure enables easy heat transfer from the heat source 2F to the main body 10F and the array of round tubes 200F. Accordingly, the heat sink 1F has improved cooling capacity despite the curved heat source 2F.

[0143] The upper surface portion 11 is curved. The upper surface portion 11 is an exemplary curved surface in this description. modification

[0144] Although the main body 10F is curved due to the shape of a curved plate of the heat source 2F in Embodiment 6, the main body 10F may also be angled at an acute or obtuse angle.

[0145] Fig. 18 is a perspective view of a heat sink 1G according to a modification of Embodiment 6. Fig. Figure 18 shows a main body 10G in translucent grey to highlight an arrangement of round tubes 200G therein, as in Fig. 17 to facilitate understanding.

[0146] The heat sink 1G includes the main body 10G, which has a plate shape angled in the front-to-back direction. In detail, the main body 10G includes a front plate 101 having a rectangular plate-like shape and whose lateral direction is oriented in the front-to-back direction, and a rear plate 102 disposed at the rear side of the front plate 101 and adjacent to the front plate 101. The lateral direction of the rear plate 102 is oriented in the direction rising toward the rear side. In other words, the lateral direction of the rear plate 102 forms an obtuse angle with the lateral direction of the front plate 101. The rear plate 102 thus rises from the front plate 101 at an obtuse angle.

[0147] The main body 10G includes the array of round tubes 200G therein, which is angled in the front-to-back direction like the main body 10G. In detail, the array of round tubes 200G includes a front portion having a net-like shape along the plate surface of the front plate 101, and a rear portion having a net-like shape along the plate surface of the rear plate 102, which rises from the front portion at an obtuse angle. This angled shape is achieved because the round tube 20G at the +Y end of the rear portion is adjacent to the -Y side and the +Z side of the round tube 20G at the rear end of the front portion and is arranged at the -Y side and +Z side of the round tube 20G at the rear end of the front portion, more specifically, the -Y end of the front portion. The arrangement of round tubes 200G having this shape receives the heat of the front plate 101 and the rear plate 102 evenly.

[0148] The main body 10G is provided with a plurality of heat sources 2G and 3G to be cooled. Specifically, a plurality of heat sources 2G are mounted on the front plate 101, while a single heat source 3G is mounted on the rear plate 102. The front plate 101 and the rear plate 102 thus absorb heat dissipated by the heat sources 2G and 3G. This absorbed heat at the front plate 101 and the rear plate 102 is evenly transferred to the array of round tubes 200G, as described above. Accordingly, cooling water flowing through the array of round tubes 200G cools the heat sources 2G and 3G.

[0149] As described above, the heat sinks 1F and 1G may comprise the main bodies 10F and 10G which are angled at an acute or obtuse angle to allow attachment of the heat sources 2G and 3G. Embodiment 7

[0150] In Embodiments 1 to 6, the heat sources 2A, 2F, 2G, and 3G are attached only to the upper surface portions 11 of the main bodies 10A, 10B, 10D, 10F, and 10G. However, these surfaces provided with the heat sources 2A, 2F, 2G, and 3G are merely examples. In a heat sink 1H according to Embodiment 7, the heat sources 2H are attached to both plate surfaces of a main body 10H.

[0151] In the following, the heat sink 1H according to Embodiment 7 is described with reference to the Fig. 19 and Fig. 20. The description of Embodiment 7 will mainly focus on the differences from Embodiments 1 to 6.

[0152] Fig. 19 is a left side view of the heat sink 1H according to Embodiment 7. Fig. 20 is a perspective view of the heat sink 1H. The Fig. 19 and Fig. 20 show the main body 1H in translucent gray to highlight an arrangement of round tubes 200H therein to facilitate understanding.

[0153] As in the Fig. 19 and Fig. 20, the heat sink 1H includes the main body 10H having a rectangular shape similar to a plate and having a plate surface facing upward, as in Embodiment 1. The main body 10H includes the arrangement of round tubes 200H therein, as in Embodiment 1.

[0154] The array of round tubes 200H is arranged such that the central axes C of the helices are aligned in the lateral direction of the main body 10H, specifically the X-direction, and includes a plurality of round tubes 20H that are adjacent to each other in the Y-direction and intertwined with each other. The array of round tubes 200H is arranged within the main body 10H at a position equidistant from the upper surface portion 11 and a lower surface portion 14. The array of round tubes 200H thus receives heat evenly from the upper surface portion 11 and the lower surface portion 14.

[0155] The upper surface part 11 and the lower surface part 14 are each provided with several heat sources 2H, as shown in Fig. 19. When the heat sources 2H are activated and release heat, the heat from the heat sources 2H is transferred to the upper surface portion 11 and the lower surface portion 14. This heat is further transferred to the array of round tubes 200H. The heat is thus transferred to the cooling water flowing through the array of round tubes 200H and is thereby released. The cooling water in the array of round tubes 200H thus cools the heat sources 2H.

[0156] As described above, in the heat sink 1H according to Embodiment 7, the heat sources 2H are attached to both the upper surface part 11 and the lower surface part 14 of the main body 10H. The main body 10H includes the array of round tubes 200H extending therein and carrying cooling water. Accordingly, the heat sink 1H can simultaneously cool the heat sources 2H on the upper surface part 11 and the lower surface part 14.

[0157] The upper surface part 11 and the lower surface part 14 are two exemplary opposing surfaces in this description. Embodiment 8

[0158] Although Embodiment 1 focuses on an example in which the array of round tubes 200A is manufactured using an additive manufacturing apparatus in the flow path formation step included in the method for manufacturing the heat sink 1A, this flow path formation step is merely an example. A method for manufacturing a heat sink according to Embodiment 8 includes a flow path formation step of intertwining the round tubes 20A, which are wound in a helical shape, using an apparatus 60, thereby forming the array of round tubes 200A.

[0159] In the following, the method for manufacturing the heat sink according to Embodiment 8 will be described with reference to the Fig. 21A to 21C, 22A to 22E, and 23A to 23D. The description of Embodiment 8 will mainly focus on the differences from Embodiments 1 to 7.

[0160] First, a configuration of the device 60 used in the flow path forming step will be described with reference to FIG. Fig. 21A to 21C.

[0161] Fig. 21A is a perspective view of the device 60 used in the method for manufacturing the heat sink according to Embodiment 8. Fig. Figure 21B is a perspective view of the device 60 when the device 60 is taken along the line XXIB-XXIB of Fig. 21A is cut open. Fig. Figure 21C is a cross-sectional view of the device 60 taken along line XXIC-XXIC of Fig. 21A. The Fig. 21A and Fig. 21B show recesses 61 in white and recesses 62 in gray to distinguish between the recesses 61 and 62 formed in the device 60.

[0162] As in the Fig. 21A and Fig. As shown in Fig. 21B, the jig 60 has a plate shape. The upper surface of the jig 60 is provided with a plurality of recesses 61 aligned in the left-right direction with the pitch P of the helix mentioned in Embodiment 1, and a plurality of recesses 62 aligned in the left-right direction with the pitch P at the positions shifted from the array of recesses 61 in the left-right direction by half the length of the pitch P. The array of recesses 61 and the array of recesses 62 are arranged alternately in the front-to-back direction in the jig 60.

[0163] As in Fig. As shown in Fig. 21C, the shapes and positions of the recesses 61 are adapted to the contour of each round tube 20A, of which the central axis C of the helix lies at the height calculated by subtracting half the length of the outer diameter φ1 of the round tube 20A from the amplitude A mentioned in Embodiment 1, from the upper surface of the jig 60. In other words, the positions and shapes of the recesses 61 are determined so that the recesses 61 accommodate the respective lower parts of the round tube 20A in the above-mentioned position, which are located below the upper surface of the jig 60. The round tube 20A fits into the recesses 61 and is thus held by the recesses 61.

[0164] The number of recesses 61 is determined such that the recesses 61 can accommodate the respective lower parts of an imaginary round tube 20A in the above-mentioned position, which are arranged below the upper surface of the device 60, assuming that the imaginary round tube 20A is twice as long as the real round tube 20A. The device 60 can accordingly hold the round tube 20A for sliding in the left-right direction.

[0165] The shapes and positions of the recesses 62 which are not in Fig. 21C are identical to those of the recesses 61, except that: (1) the recesses 62 are shifted from the recesses 61 in the left-right direction by half the length of the pitch P; and (2) the recesses 62 are shifted from the recesses 61 in the front or rear direction by the interval between the central axes C mentioned in Embodiment 1. The number of the recesses 62 is determined in the same way as that of the recesses 61.

[0166] The recesses 61 and 62, which have the above-mentioned shapes and are arranged at the above-mentioned positions, represent the shapes of the lower parts of the round tubes 20A when the array of round tubes 200A is placed on the upper surface of the device 60. Fitting the individual round tubes 20A into the recesses 61 and 62 in the device 60 can therefore determine the positions of the round tubes 20A in the array of round tubes 200A.

[0167] The description is then directed to the flow path forming step using the device 60 with reference to the Fig. 22A to 22E and 23A to 23D. Of a plurality of round tubes 20A to be intertwined in the flow path forming step, a first round tube is designated by reference numeral 20I in the following description, and a second round tube to be intertwined with the first round tube is designated by reference numeral 20J for ease of understanding. The resulting arrangement of round tubes is designated by reference numeral 200I.

[0168] Fig. 22A is a perspective view of the jig 60 used in the method for manufacturing the heat sink according to Embodiment 8 when the jig 60 holds the first round tube 20I. Fig. 22B is a perspective view of the device 60 when the device 60 holds the second round tube 20J in addition to the first round tube 20I. Fig. 23A is a perspective view of the first round tube 20I to be held in the device 60 in this flow path forming step. Fig. 23A to 23D show only the first round tube 20I and the second round tube 20J without the device 60 to facilitate understanding of the state of the first round tube 20I and the second round tube 20J.

[0169] First, several round tubes 20A are prepared as described in embodiment 1. As in Fig. 22A, a first round tube 20I of the round tubes 20A is then fitted into the arrangement of the recesses 61 at the rear right end of the device 60. The first round tube 20I is thereby held on the device 60. The position of the first round tube 20I is thus determined such that the central axis C of the helix is ​​aligned in the left-right direction, as shown in Fig. 23A shown.

[0170] As in Fig. As shown in Figure 22B, a second round tube 20J, different from the first round tube 20I, is fitted into the array of recesses 62 at the rear right end of the jig 60, which is adjacent to and disposed against the front of the array of recesses 61 receiving the first round tube 20I. Accordingly, the second round tube 20J is also retained on the jig 60, and the position of the first round tube 20J is also determined such that the central axis C of the helix is ​​oriented in the left-right direction.

[0171] The step of fitting the first round tube 20I into the array of recesses 61 and the step of fitting the second round tube 20J into the array of recesses 62 are collectively referred to as the round tube alignment step in this specification.

[0172] In this situation, the second round tube 20J is rotated clockwise. The clockwise direction indicates the clockwise direction viewed from the left side of the second round tube 20J to the right side, specifically from the -X side to the +X side, as described in the description of Embodiment 1.

[0173] Fig. 23B is a perspective view of the round tubes 20I and 20J after the second round tube 20J has been rotated so that the right end of the second round tube 20J is intertwined with the left end of the first round tube 20I.

[0174] When the second round tube 20J is rotated clockwise, the second round tube 20J is guided by the recesses 62 while being displaced in the recesses 62 on the jig 60. The second round tube 20J shifts correspondingly in the right direction. In response to each rightward displacement of the second round tube 20J by the pitch P, the recesses 62 guide the second round tube 20J to a position to cause the second round tube 20J to intertwine with the first round tube 20I fitted in the recesses 61. The second round tube 20J is thereby gradually intertwined with the first round tube 20I. In the first stage, the right end of the second round tube 20J is intertwined with the left end of the first round tube 20I, as shown in Fig. 23B shown.

[0175] The round tubes 20I and 20J are exemplary first and second tubes, respectively, in this specification. The step of intertwining the right end of the second round tube 20J with the left end of the first round tube 20I is an exemplary step of arranging the first tube and the second tube in this specification. This step is also referred to as the tube arranging step in this specification.

[0176] Fig. 22C is a perspective view of the jig 60 after the second round tube 20J has been rotated on the jig 60 to be intertwined with the left half of the first round tube 20I. Fig. 22D is a perspective view of the device 60 after the second round tube 20J has been further rotated on the device 60 to be entwined with the entire first round tube 20I.

[0177] Fig. 23C is a perspective view of the round tubes 20I and 20J after the second round tube 20J has been further rotated to be intertwined with the left half of the first round tube 20I. Fig. 23D is a perspective view of the round tubes 20I and 20J after the second round tube 20J has been further rotated to be entwined with the entire first round tube 20I.

[0178] When the second round tube 20J is rotated clockwise, the right end of the second round tube 20J is intertwined with the left end of the first round tube 20I, as shown in Fig. 23B. Further rotation of the second round tube 20J causes further entanglement of the second round tube 20J with the first round tube 20I. The second round tube 20J is initially entangled with the left half of the first round tube 20I, as shown in the Fig. 22C and Fig. 23C, and then entwined with the entire first round tube 20I, as shown in the Fig. 22D and Fig. 23D shown.

[0179] The step of interlacing the second round tube 20J with the entire first round tube 20I is an exemplary step of interlacing the second tube with the first tube in this description. This step is also referred to as a weaving step because it involves alternately combining the second round tube 20J and the first round tube 20I to weave a single product.

[0180] Then, a third round tube 20A is fitted into the array of recesses 61 located adjacent to and arranged on the front side of the array of recesses 62 receiving the second round tube 20J. This third round tube 20A is then intertwined with the entire second round tube 20J through the aforementioned round tube alignment step, tube arrangement step, and weaving step. These steps are further repeated.

[0181] Fig. 22E is a perspective view of the device 60 after an arrangement of round tubes 200I has been formed by intertwining a large number of round tubes 20I and 20J on the device 60.

[0182] The repetition of the round tube alignment step, tube arrangement step and weaving step described above represents the Fig. 22E. After the arrangement of round tubes 200I is manufactured, the resulting arrangement of round tubes 200I is removed from the device 16.

[0183] The array of round tubes 200I removed from the fixture 60 is then inserted into the metal material by potting. This process completes the heat sink 1A.

[0184] As described above, the flow path formation step in the method for manufacturing the heat sink according to Embodiment 8 is performed using the jig 60. The jig 60 holds a plurality of round tubes 20I and 20J having a helical shape so that the round tubes 20I and 20J are rotatable about their helical central axes. When the second round tube 20J is rotated about the helical central axis while the first round tube 20I is held in a certain position, the jig 60 guides the second round tube 20J to a position to cause the second round tube 20J to intertwine with the first round tube 20I. The method for manufacturing the heat sink according to Embodiment 8 can therefore easily cause the round tubes 20I and 20J to intertwine with each other to form the array of round tubes 20I. Embodiment 9

[0185] In the method for manufacturing the heat sink 1B according to Embodiment 2, the round tubes 20B are plated to prevent corrosion due to mutually different metal materials constituting the main body 10B and the round tubes 20B. However, this manufacturing method is merely an example for preventing corrosion due to mutually different materials constituting the main body 10B and the round tubes 20B. A method for manufacturing a heat sink 1K according to Embodiment 9 includes a step of dissolving round tubes 20K and thereby removing the round tubes 20K after an array of round tubes 200K is inserted into a metal material constituting a main body 10K by molding to obtain the main body 10K.

[0186] In the following, the method for manufacturing the heat sink 1K according to Embodiment 9 will be described with reference to the Fig. 24A, Fig. 24B, Fig. 25A and Fig. 25B. The description of Embodiment 9 will mainly focus on the differences from Embodiments 1 to 8.

[0187] Fig. 24A is a perspective view of a main body 10K manufactured by inserting the array of round tubes 200K into a metal material constituting the main body 10K by molding in the method for manufacturing the heat sink 1K according to Embodiment 9. Fig. Figure 24B is an enlarged view of area XXIVB of Fig. 24A. Fig. 25A is a perspective view of the main body 10K after the round tube array 200K is removed by dissolving the round tube array 200K in this manufacturing process. Fig. Figure 25B is an enlarged view of area XXVB of Fig. 25A. The Fig. 24A, Fig. 24B, Fig. 25A and Fig. 25B show the main body 10K in translucent gray to highlight an arrangement of round tubes 200K therein to facilitate understanding.

[0188] In the method for manufacturing the heat sink 1K, round tubes 20K having a shape identical to that in Embodiment 1 are prepared with a specific metal material, such as iron and steel. The resulting round tubes 20K are intertwined to form an array of round tubes 200K. This array of round tubes 200K is then inserted into another metal material, such as an aluminum alloy, by casting. This process represents a Fig. 24A shown main body 10K.

[0189] In the case where the array of round tubes 200K and the main body 10K are made of different metal materials and these metal materials have a significant difference in ionization tendency, potential differences occur between the array of round tubes 200K and the main body 10K and induce flow therebetween, as mentioned in Embodiment 2. These flow may lead to corrosion in the array of round tubes 200K and the main body 10K.

[0190] To solve this problem, a solution such as hydrochloric acid, sulfuric acid, or aqua regia is used to dissolve the metal material that makes up the 20K round tubes, through the openings of the 20K round tubes, more precisely the openings in the Fig. 24A and Fig. 24B, which are exposed on the end surface of the manufactured main body 10K, are introduced in the process of manufacturing the heat sink 1K. This process dissolves the metal material constituting the round tubes 20K.

[0191] The dissolution of the metal material that makes up the round tubes 20K results in the removal of the round tubes 20K from the main body 10K, as shown in the Fig. 25A and Fig. 25B. This process completes the 1K heat sink.

[0192] This manufacturing process provides the heat sink 1K with flow paths 70 having inner walls made of the same material as the material constituting the main body 10K. The process also provides the main body 10K with an array of flow paths 71 including the intertwined flow paths 70. Since the array of flow paths 71 has an inner wall made of the same metal material as the main body 10K, the flow paths 70 and the main body 10K have no potential difference between them and do not cause any flow of current. The heat sink 1K is accordingly free from corrosion due to a potential difference.

[0193] The metal material constituting the main body 10K is an exemplary first metal material in this description. The metal material constituting the round tubes 20K is an exemplary fourth metal material in this description. Hydrochloric acid, sulfuric acid, and aqua regia are exemplary solutions in this description.

[0194] As described above, the method for manufacturing the heat sink 1K according to Embodiment 9 includes a step of introducing a solution for dissolving the metal material constituting the round tubes 20K into the round tubes 20K, dissolving the metal material constituting the round tubes 20K, and thereby removing the round tubes 20K from the main body 10K. In the resulting heat sink 1K, the inner walls of the flow paths 70 and the main body 10K are made of the same material. This heat sink 1K can accordingly prevent corrosion due to a difference in ionization tendency between the materials constituting the inner walls of the flow paths 70 and the main body 10K.

[0195] Although the heat sinks 1A, 1B, 1D to 1H, and 1K for air conditioning devices according to embodiments of the present disclosure are described above, these heat sinks 1A, 1B, 1D to 1H, and 1K are merely examples. Although the flow paths for the coolant are defined by the round tubes 20A to 20D and 20F to 20J in Embodiments 1 to 8, these flow paths are merely examples. What is necessary is that flow paths extend in a helix shape, and flow paths of which the central axes of the helices are adjacent to each other are intertwined with each other, for example. Specifically, the flow paths may have any cross-sectional shape, in other words, any tube cross-sectional shape. For example, the flow paths may be defined by flat tubes having a flattened tube cross-sectional shape.

[0196] The flow paths are not necessarily defined by tubes. In other words, the flow paths do not have to be independent of the main bodies 10A, 10B, 10D, 10F, 10G, 10H, and 10K. The flow paths may be the flow paths formed in the main bodies 10A, 10B, 10D, 10F, 10G, 10H, and 10K, as in Embodiments 5 and 9.

[0197] In Embodiments 1 to 9, the central axes C of the helices of the round tubes 20A to 20D and 20F to 20K are parallel to each other. In other words, the flow paths, which have a helical shape, are arranged so that the central axes of the helices are parallel to each other. However, these flow paths are merely examples. In an exemplary case where the helices of the round tubes 20A to 20D and 20F to 20K are not normal helices, in detail where the helices of the round tubes 20A to 20D and 20F to 20K have an outer diameter φ2 that gradually increases in a certain direction along each of the central axes C of the helices, the central axis C of the helix of one of the round tubes 20A to 20D and 20F to 20K may be increasing from the central axis C of the helix of an adjacent one of the round tubes 20A to 20D and 20F to 20K.

[0198] In Embodiments 1 to 9, the adjacent circular tubes 20A to 20D and 20F to 20K are intertwined with each other in each cycle of the helix. In other words, the adjacent flow paths are connected to each other in each cycle of the helix. However, these flow paths are merely examples. For example, the adjacent flow paths may also be intertwined with each other once every integer number of cycles greater than or equal to two. In this case, the helix of one of the adjacent flow paths preferably has a cycle equal to the value calculated by multiplying the cycle of the helix of the other flow path by the integer number greater than or equal to two.In another case, where the helices of the flow paths have an outer diameter φ2 that increases or decreases in every integer number of cycles greater than or equal to two cycles, the adjacent flow paths may be intertwined with each other in each of the cycles.

[0199] Although the plurality of round tubes 20A to 20D and 20F to 20K are intertwined to configure the mesh-like arrangement of round tubes 200A, 200B, 200D, 200F to 200I, and 200K in Embodiments 1 to 9, the arrangements of round tubes 200A, 200B, 200D, 200F to 200I, and 200K can also be referred to as woven tube arrangements. This is because the word "weaving" means alternately combining long and thin materials to form a single product.

[0200] In Embodiment 2, the supply flow paths 31 and the discharge flow paths 32, which are made of a metal material having an ionization tendency significantly different from that of the material constituting the round tubes 20B, are provided adjacent to both ends of the round tubes 20B. However, the heat sinks 1A, 1B, 1D to 1H, and 1K may have other configurations. When one part of the flow path is made of a metal material having an ionization tendency different from that of the other part of the flow path, in the heat sinks 1A, 1B, 1D to 1H, and 1K, one part of the flow path is preferably plated with a different material having an ionization tendency closer to that of the metal material constituting the other part of the flow path than that of the metal material constituting one part of the flow path.One part of the flow path may correspond to the inner walls of the round tubes 20A to 20D and 20F to 20K, and the other part of the flow path may correspond to the headers. For example, one part of the flow path may correspond to the inner walls of the round tubes 20A, and the other part of the flow path may correspond to the inlet header 41 and the outlet header 42 in Embodiment 4. In this case, the inner walls of the round tubes 20A are preferably plated with a metal material having an ionization tendency closer to the metal material constituting the inlet header 41 and the outlet header 42 than to that of the metal material constituting the round tubes 20A.

[0201] Although the surfaces of the heat sinks 1A, 1B, 1D to 1H, and 1K are provided with the heat sources 2A, 2F, 2G, 2H, and 3G facing upward in Embodiments 1 to 9, these surface orientations in Embodiments 1 to 9 are for illustrative purposes only. Specifically, the surfaces of the heat sinks 1A, 1B, 1D to 1H, and 1K to be provided with the heat sources 2A, 2F, 2G, 2H, and 3G may face any direction. The round tubes 20A to 20D and 20F to 20K and the through holes 51 may also extend in any direction and may be intertwined with each other in any direction.

[0202] Although the heat sources 2A, 2F, 2G, 2H, and 3G to be cooled are power semiconductor devices in Embodiments 1 to 9, the heat sinks 1A, 1B, 1D to 1H, and 1K can also cool other devices. Examples of the devices to be cooled include central processing units of computers and semiconductor devices such as light-emitting diodes. The devices to be cooled can be devices, machines, or appliances that dissipate heat.

[0203] In embodiments 1 to 9, the main bodies 10A, 10B, 10D, 10F, 10G, 10H, and 10K are independent of the components included in the devices to be cooled and are dedicated to the heat sinks 1A, 1B, 1D to 1H, and 1K. However, these main bodies 10A, 10B, 10D, 10F, 10G, 10H, and 10K are merely examples. The main bodies 10A, 10B, 10D, 10F, 10G, 10H, and 10K can also serve as components of the machines or devices to be cooled. In other words, the main bodies 10A, 10B, 10D, 10F, 10G, 10H, and 10K can be incorporated into the machines or devices to be cooled as components of the machines or devices. For example, the main bodies 10A, 10B, 10D, 10F, 10G, 10H, and 10K can be incorporated into the machines to be cooled as components, such as housings or bases.In detail, although the main body 10A is also referred to as a block as mentioned in Embodiment 1, the main body 10A may be incorporated in a machine as a block supporting a heat-dissipating component to be cooled, or as a block forming part of a casing accommodating a heat-dissipating component. List of reference symbols 1A, 1B, 1D to 1H, 1K heat sink 2A, 2F, 2G, 2H, 3G heat source 5 lower surface 10A, 10B, 10D, 10F, 10G, 10H, 10K main body 11 upper surface part 12 left surface part 13 right surface part 14 lower surface part 20A to 20D, 20F to 20K round tube 21 Feed connection 22 Drain connection 23 Coating 24 Board of Directors 31 Feed flow path 32 Drain flow path 41 Inlet head part 42 Outlet head part 43 Inlet pipe 44 Outlet pipe 50 plate-like element 51 through hole 60 device 61, 62 Deepening 70 River Trail 71 Arrangement of river paths 90 mold 91, 92 plate 93, 94 core 95 Cast hole 101 front plate 102 rear plate 200A, 200B, 200D, 200F to 200I, 200K Arrangement of round tubes 500 layered bodies 911, 921 recess A Amplitude A1, A2 arrow B rear end part C Central axis F front end part IC inner circumference L length OC outer circumference P gradient φ1, φ2 outer diameter

Claims

[1] Heat sink (1A, 1B, 1D, 1E, 1F, 1G, 1H, 1K), comprising: a main body (10A, 10B, 10D, 10F, 10G, 10H, 10K) in contact with at least one heat source (2A, 2F, 2G, 2H, 3G); and a plurality of flow paths (70) arranged within the main body (10A, 10B, 10D, 10F, 10G, 10H, 10K) and extending in a helical shape, wherein the plurality of flow paths (70) are configured to convey a coolant, wherein the plurality of flow paths (70) are arranged such that central axes (C) of the helices are adjacent to one another, and in each case two adjacent flow paths (70) of the plurality of flow paths (70) are intertwined with one another, wherein the central axes (C) of the helices of adjacent flow paths (70) of the plurality of flow paths (70) lie adjacent to one another. [2] The heat sink (1A, 1B, 1D, 1E, 1F, 1G, 1H, 1K) according to claim 1, wherein the flow paths (70) of which the central axes (C) of the helices are adjacent to each other are intertwined with each other so that the plurality of flow paths (70) has a net shape or a woven shape. [3] Heat sink (1A, 1B, 1D, 1E, 1F, 1G, 1H, 1K) according to claim 1 or 2, wherein the central axes (C) of the helices are parallel to each other, and the flow paths (70) of which the central axes (C) of the helices are adjacent to each other are intertwined in every integer number of cycles of the helices. [4] Heat sink (1A) according to one of claims 1 to 3, wherein each of the plurality of flow paths has a shape of a round tube (20A) having a center winding along a helix corresponding to the flow path, and if the central axes (C) of the helices extend in an X-direction and are adjacent to each other in a Y-direction, and the X-direction and the Y-direction are orthogonal to a Z-direction, a pitch of the helices and an amplitude of the helices satisfy expressions 1 and 2, and a trajectory of a center of an n-th round tube (20A) in the Y-direction satisfies expressions 3, 4 and 5 on a radian basis: P=4φ1(σ+1) A=φ1(σ+1) X=tL Y=A cos{360tLP+180(n−1)}+A(n−1) Z=A sin{360tLP+180(n−1)} where φ1 indicates an outer diameter of the round tubes (20A), L indicates a length of the central axes (C) of the helices, P indicates the pitch of the helices, A indicates the amplitude of the helices, σ indicates a distance factor that represents a measure of a minimum distance between the round tubes (20A) whose central axes (C) of the helices are adjacent to each other and satisfies the expression σ < 1, and t indicates an influence quantity and satisfies an expression 0 ≤ t ≤ 1. [5] The heat sink (1F) according to any one of claims 1 to 4, wherein the main body (10F) has a curved surface in contact with the at least one heat source (2F), and the plurality of flow paths are curved and arranged along the curved surface. [6] Heat sink (1H) according to one of claims 1 to 5, wherein the at least one heat source (2H) is a plurality of heat sources (2H), and the main body (10H) has two opposing surfaces, each of the surfaces being in contact with one of the plurality of heat sources (2H). [7] Heat sink (1A, 1B, 1D, 1E, 1F, 1G, 1H) according to one of claims 1 to 6, wherein the main body (10A, 10B, 10D, 10F, 10G, 10H) is a metal block in which a plurality of metal tubes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J) extend, each of the plurality of metal tubes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J) being wound in a helical shape, and the plurality of flow paths are spaces surrounded by inner walls of the plurality of metal pipes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J). [8] Heat sink (1B) according to claim 7, wherein the main body (10B) is made of a first metal material, the plurality of metal tubes (20B) are made of a second metal material having a higher ionization tendency than an ionization tendency of the first metal material, and each of the plurality of metal tubes (20B) comprises a coating (23) covering an inner wall of a corresponding metal tube (20B), the coating (23) being made of a third metal material, the third metal material having an ionization tendency higher than the ionization tendency of the first metal material and lower than the ionization tendency of the second metal material, and in particular having an ionization tendency closer to the ionization tendency of the first metal material than to the ionization tendency of the second metal material. [9] The heat sink (1A, 1B) according to any one of claims 1 to 8, wherein each of the plurality of flow paths includes a protrusion (24) projecting inwardly from the flow path. [10] The heat sink (1A, 1B) according to claim 9, wherein the protrusion (24) extends in a conveying direction of the coolant. [11] The heat sink (1A, 1B) according to claim 9 or 10, wherein the protrusion (24) has a shape of a rectangle including sharp edges in a cross section perpendicular to a conveying direction of the coolant. [12] The heat sink (1A, 1B) according to claim 9 or 10, wherein the protrusion (24) has a shape of a rectangle including rounded edges in a cross section perpendicular to a conveying direction of the coolant. [13] Heat sink (1D) according to one of claims 1 to 12, further comprising: a first header (41) connected to the ends of the plurality of flow paths to which the coolant is supplied, the first header (41) being configured to distribute the coolant to the plurality of flow paths; and a second header (42) connected to the ends of the plurality of flow paths from which the coolant is discharged, the second header (42) being configured to collect the coolant from the plurality of flow paths. [14] A method for manufacturing a heat sink (1A, 1B, 1D, 1E, 1F, 1G, 1H, 1K), the method comprising: Forming a plurality of flow paths (70) for conveying a coolant by manufacturing a plurality of tubes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J, 20K) wound in a helical shape, wherein the plurality of tubes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J, 20K) are arranged so that central axes (C) of the helices lie next to each other, with two of the plurality of tubes, the central axes of the helices lying next to each other, being intertwined with each other; and Inserting the plurality of tubes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J, 20K) produced during the forming process into a first metal material by casting. [15] The method of claim 14, wherein said forming comprises: Arranging a first tube (20I) from the plurality of tubes (20I, 20J) and a second tube (20J) of the plurality of tubes (20I, 20J) such that one end of the second tube (20J) is intertwined with one end of the first tube (20I), the first tube (20I) being different from the second tube (20J); and Intertwining the second tube (20J) with the first tube (20I) by rotating the second tube (20J) about a central axis (C) of a helix corresponding to the second tube (20J), while holding the first tube (20I) in a certain position and sliding one end of the second tube (20J) towards the other end of the first tube (20I) until one end of the second tube (20J) is aligned with the other end of the first tube (20I), the other end of the first tube (20I) being opposite one end of the first tube (20I), where the entanglement follows the arrangement. [16] A method according to claim 14 or 15, wherein the central axes (C) of the helices are made parallel to each other in the forming and the tubes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J, 20K) of which the central axes (C) of the helices are adjacent to each other are intertwined with each other in every integer number of cycles of the helices. [17] The method of any one of claims 14 to 16, wherein the plurality of tubes (20A, 20B, 20C, 20D, 20F, 20G, 20H, 20I, 20J, 20K) are formed by an additive manufacturing apparatus during the forming step. [18] The method of any one of claims 14 to 17, wherein the plurality of tubes (20B) are formed with a second metal material during the forming, and the method further comprises, prior to the inserting, plating inner walls of the plurality of tubes (20B) with a third metal material having an ionization tendency closer to an ionization tendency of the first metal material than to an ionization tendency of the second metal material. [19] Method according to one of claims 14 to 17, wherein the plurality of tubes (20K) is manufactured with a fourth metal material during the forming, and the post-insertion procedure further includes: Removing the plurality of tubes (20K) inserted during the insertion from the first metal material by introducing a solution for dissolving the fourth metal material into the plurality of tubes (20K) and thereby dissolving the fourth metal material forming the plurality of tubes (20K) by the solution. [20] A method for manufacturing a heat sink (1E), wherein the heat sink (1E) comprises a block and a plurality of flow paths, wherein the plurality of flow paths are arranged within the block and extend in a helical shape, wherein the plurality of flow paths are arranged such that central axes (C) of the helices are adjacent to one another, wherein each two adjacent flow paths of the plurality of flow paths are intertwined with one another, wherein the central axes (C) of the helices of adjacent flow paths of the plurality of flow paths are adjacent to one another, the method comprising: Producing a plurality of plate-like elements (50), each having a plate surface perpendicular to the central axes (C) of the helices and provided with parts of the plurality of flow paths; and Configuring a block (500) comprising the plurality of flow paths by stacking the plurality of plate-like elements (50) together.

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