Liquid cooling module

Abstract

To suppress a height while securing cooling performance of a liquid-cooled module.SOLUTION: A liquid-cooled module 30 includes: a heat reception part 46 that provides a heat reception surface 48; a first passage part 56 in which a flow pass FP is continuously expanded from an inlet part 52 in a fan shape; a second passage part in which the flow pass FP is formed toward the heat reception part; a diffusion part in which a plurality of grooves for diffusing a coolant is formed; and a third passage part in which the flow pass is formed to a direction separated from the heat reception part. In addition, the liquid-cooled module comprises an outlet 68 making the coolant flows, and includes an outlet part 66 in which the flow pass is communicated with the outlet 68 from the third passage part. The flow pass FP of the inlet part 52 and the flow pass FP of the outlet part 66 are positioned at a same height position from the heat reception surface 48.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0001] The technology disclosed in the present application relates to a liquid cooling module.

Background Art

[0002] There is a structure in which a cooling block is arranged on the back side of a heating element chip to cool the heating element chip and keep the temperature of the semiconductor element in the chip at a constant temperature. In this structure, a part of the flow rate of the refrigerant liquid flowing in the main flow path pipe is branched by a refrigerant liquid branching mechanism having a pipe structure and is guided to the heating element chip side of the cooling block. Cooling fins are arranged parallel or radially in the surface of the side of the cooling block that contacts the heating element chip, and the refrigerant liquid flows between the fins. At this time, the refrigerant liquid removes the heat generated in the heating element chip via phosphorus and is heated itself.

[0003] Also, there is a structure in which a semiconductor element such as a CPU and a cooling plate are thermally adhered to each other, and partition plates are provided in the cooling plate, with both ends of the partition plates provided on one side of the piping side and the rest arranged in a staggered pattern to form a flow path. In this structure, an intake pipe and a discharge pipe are arranged on one side of the cooling plate, and no space for piping is required in front of and behind the cooling plate in a high-density mounted product, and the piping can be compactly accommodated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0006] Therefore, one aspect of the technology disclosed in this application is to ensure the cooling performance of the liquid cooling module while suppressing its height. [Means for solving the problem]

[0007] To achieve the above objective, according to one aspect of the technology disclosed in this application, the liquid cooling module has a heat receiving section having a heat receiving surface that receives heat from the object to be cooled, and an inlet section having an inlet into which a liquid coolant that exchanges heat in the heat receiving section flows, and a flow path formed through which the coolant flowing in from the inlet flows. Furthermore, the liquid cooling module has a first flow path section in which the flow path is continuous from the inlet section and spreads out in a fan shape when viewed in the direction normal to the heat receiving surface, and a second flow path section in which the flow path is continuous from the first flow path section and formed toward the heat receiving section. Furthermore, the liquid cooling module has a diffusion section in the heat receiving section in which a plurality of grooves are formed that are continuous from the flow path of the second flow path section and diffuse the coolant along the surface opposite to the heat receiving surface, and a third flow path section in which the flow path is continuous from the plurality of grooves and formed in a direction away from the heat receiving section. Furthermore, the liquid cooling module has an outlet section in which the coolant is discharged and the flow path is continuous from the third flow path section to the outlet. The flow path of the inlet section and the flow path of the outlet section are at the same height from the heat receiving surface. [Effects of the Invention]

[0008] According to the technology disclosed in this application, for example, it is possible to ensure the cooling performance of a liquid cooling module while suppressing its height. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view of an electronic device equipped with a liquid cooling module according to one embodiment of the technology disclosed in this application. [Figure 2]This is a perspective view showing a liquid-cooled module according to one embodiment of the technology disclosed in this application. [Figure 3] This is an exploded perspective view showing a liquid cooling module according to one embodiment of the technology disclosed in this application. [Figure 4] This is a plan cross-sectional view showing a liquid-cooled module according to one embodiment of the technology disclosed in this application. [Figure 5] This is a cross-sectional view taken along line 5-5 of Figure 4, showing a liquid-cooled module according to one embodiment of the technology disclosed in this application. [Figure 6] This is a cross-sectional view taken along line 6-6 of Figure 4, showing a liquid-cooled module according to one embodiment of the technology disclosed in this application. [Modes for carrying out the invention]

[0010] An embodiment of the technology disclosed in this application will be described below.

[0011] Figure 1 shows a plan view of an electronic device 10 equipped with a liquid cooling module 30 according to one embodiment of the technology disclosed in this application. As shown in Figure 1, the electronic device 10 has a housing 12. The housing 12 is, for example, a rectangular box-shaped member. The front side in the front-to-back direction of the electronic device 10 is indicated by the arrow FR, the right side in the width direction by the arrow RF, and the top side in the height direction by the arrow UP. The electronic device 10 is, for example, a server, and more specifically, a rack-mount server. A rack-mount server is mounted on a rack in a orientation such that the height direction of the rack-mount server is vertical.

[0012] An auxiliary storage device such as an HDD (Hard Disk Drive) 16 is mounted on the front side of the inside of the enclosure 12. A fan 18 is mounted on the rear side of the HDD 16. Further behind the fan 18, a main storage device such as a DIMM (Dual Inline Memory Module) 20 and a processor (processing unit) such as a CPU (Central Processing Unit) 22 are arranged in the width direction. The CPU 22 and DIMM 2024 are mounted on a circuit board 14 (see Figures 5 and 6), etc.

[0013] In the example shown in Figure 1, there are two CPUs 22. For each CPU 22, two corresponding DIMMs 20 are arranged on both sides in the width direction. Each CPU 22 and the corresponding DIMMs 20 on both sides are electrically connected, for example, by wiring patterns on the circuit board 14, and electrical signals are exchanged between them.

[0014] The CPU 22 is an example of a "cooling target" related to the technology disclosed herein. With respect to the CPU 22, the fan 18 is located on the front side of the CPU 22, and the DIMMs 20 are located on both the left and right sides in the width direction.

[0015] The fan 18 generates airflow in the direction indicated by arrow F1 in Figure 1. This airflow cools the DIMM 20. The DIMM 20 is an example of a "second cooling target" related to the technology of this disclosure.

[0016] Inside the rear of the enclosure 12, connection devices such as PCI (Peripheral Component Interconnect) 24 and power supply devices such as PSU (Power Supply Unit) 26 are mounted.

[0017] The liquid cooling modules 30 shown in Figures 2 to 6 are provided corresponding to each CPU 22 and cool the CPU 22 by receiving heat from the CPU 22. In this embodiment, there are two CPUs 22, so there are also two liquid cooling modules 30. In the following, the two liquid cooling modules 30 will be distinguished as liquid cooling module 30L on the left side in the width direction and liquid cooling module 30R on the right side in the width direction. In both liquid cooling modules 30, in a plan view, that is, in the direction normal to the heat receiving surface 48 described later, the CPU 22 overlaps the liquid cooling module 30 at its center. In this embodiment, the direction normal to the heat receiving surface 48 is also the height direction of the liquid cooling module 30.

[0018] In this embodiment, the front-back direction, width direction, and depth direction of the liquid cooling module 30 coincide with the front-back direction, width direction, and depth direction of the electronic device 10. Therefore, the arrows FR, RF, and UP in FIGS. 2 to 6 indicate the front side in the front-back direction, the right side in the width direction, and the upper side in the up-down direction in the liquid cooling module 30, respectively.

[0019] As shown in FIG. 2, the liquid cooling module 30 has a cold plate 32. As also shown in FIG. 3, the cold plate 32 has a base 34, a cover 36, and a flow path block 38.

[0020] The base 34 is a plate-like member. For example, at each of the four corners, it is fixed to the substrate 14 or the like by a fastener 40.

[0021] As will be described later, the flow path block 38 is a member in which recesses and holes forming a flow path FP of a predetermined shape are formed, and is mounted on the base 34.

[0022] The cover 36 is a box-shaped member with an open lower surface side. The cover 36 is fixed to the base 34 in a state of covering the upper surface, right side surface, left side surface, front surface, and rear surface of the flow path block 38 mounted on the base 34. In a portion where a recess is formed in the flow path block 38, the cover 36 covers the flow path block 38 in this way, so that the recess forms the flow path FP. Note that the flow path block 38 and the cover 36 are shaped so as not to interfere with the fastener 40.

[0023] On the rear side of the cold plate 32, a convex portion 42 that protrudes convexly backward is formed at the center in the width direction. The rear surface of the convex portion 42 is an opening surface 44. An inlet 54 and an outlet 68 are opened in the opening surface 44 as will be described later.

[0024] As shown in Figures 5 and 6, the lower part of the liquid cooling module 30 is a heat receiving section 46. The heat receiving section 46 has a heat receiving surface 48 on the lower surface of the base 34. The heat receiving surface 48 is placed on the upper surface of the CPU 22 via a heat transfer member 50 such as a heat transfer sheet or grease. The heat receiving surface 48 is the surface that receives heat from the CPU 22.

[0025] The liquid cooling module 30 has an inlet 52, a first flow path 56, a second flow path 58, a diffusion section 60, a third flow path 64, and an outlet 66 inside the cold plate 32. The liquid cooling module 30 has flow paths FP formed in which the liquid coolant flows in the order of inlet 52, first flow path 56, second flow path 58, diffusion section 60, third flow path 64, and outlet 66.

[0026] The inlet portion 52 and the outlet portion 66 are located within the cold plate 32, specifically at the top of the cold plate 32.

[0027] The inlet section 52 has an inlet 54 that opens to the opening surface 44. A pipe 72 is connected to the inlet 54 via a connector 80. As shown in Figure 3, the inlet 54 is continuous with the flow path FP in the inlet section 52 of the flow path block 38.

[0028] As shown in Figures 3 and 4, the flow path FP of the inlet 52 extends forward from the inlet 54, curves to the left in the width direction, then curves forward, and then curves to the right in the width direction. Furthermore, the flow path FP of the inlet 52 is parallel to the heat receiving surface 48 (see Figure 5) along its entire length.

[0029] As shown in Figures 3 to 5, the flow path FP of the inlet section 52 is continuous with the flow path FP of the first flow path section 56. The flow path FP of the first flow path section 56 has a fan-shaped structure that spreads out from the tip of the flow path FP on the inlet section 52 side when viewed in plan, that is, in the direction normal to the heat receiving surface 48.

[0030] This "fan shape" refers to a shape that widens to the left and right with respect to the center on the downstream side in the flow direction of the refrigerant flowing in from the flow path FP of the inlet section 52. In the example shown in Figure 4, the flow path FP of the first flow path section 56 has a shape that widens in the front-to-back direction as it moves from the left side in the width direction to the right side in the width direction. In a plan view, this fan-shaped flow path FP is located in the center in the front-to-back direction and the center in the width direction of the liquid cooling module 30.

[0031] Furthermore, as shown in Figure 5, the bottom surface 56B of the flow path FP in the first flow path section 56 is inclined so as you move from the left side in the width direction to the right side in the width direction, away from the heat receiving surface 48, i.e., upward. The inclination angle θ of the bottom surface 56B of the flow path FP in the first flow path section 56 is constant at any position in the flow path FP of the first flow path section 56. This inclination angle θ is the angle of the bottom surface 56B of the flow path FP with respect to the surface PP parallel to the heat receiving surface 48. Also, the bottom surface 56B of the flow path FP in the first flow path section 56 is not inclined in the fan-shaped spreading direction, i.e., in the front-to-back direction of the liquid cooling module 30.

[0032] The length of the inclined portion at the bottom surface 56B of the flow path FP of the first flow path section 56 is longer in the center of the sector and shorter on both sides of the sector (both sides in the front-to-back direction of the liquid cooling module 30). For example, comparing the flow path FP of the first flow path section 56 in the cross-section shown in Figure 5 with the flow path FP of the first flow path section 56 in the cross-section shown in Figure 6, the flow path FP shown in Figure 5 is longer.

[0033] The flow path FP of the second flow path section 58 is continuous with the leading edge of the flow path FP of the first flow path section 56. The flow path FP of the second flow path section 58 is formed toward the heat receiving section 46, that is, toward downward.

[0034] As shown in Figure 4, the flow path FP of the second flow path section 58 has the same opening length as the flow path FP of the first flow path section 56 in the front-to-back direction of the liquid cooling module 30. In contrast, in the width direction of the liquid cooling module 30, it has a shorter opening width (opening length in the width direction of the liquid cooling module 30) compared to, for example, the inner diameter of the flow path of the inlet section 52. Furthermore, the opening width of the flow path FP of the second flow path section 58 gradually narrows from the center in the front-to-back direction towards both ends.

[0035] The diffusion section 60 is provided in the heat receiving section 46. On the upper surface of the base 34, that is, the surface opposite the heat receiving surface, a plurality of grooves 62 are formed that are continuous with the flow path FP of the second flow path section 58. The flow path FP of the diffusion section 60 is a microchannel structure that diffuses the refrigerant through these plurality of grooves 62. Specifically, each of the plurality of grooves 62 extends in the width direction of the cold plate 32, and these plurality of grooves 62 cause the liquid refrigerant to spread in the width direction. In addition, the plurality of grooves 62 are formed at a constant interval (pitch) in the front-rear direction of the cold plate 32. The portion in which the grooves 62 are formed is in the same range as the flow path FP of the second flow path section 58 in the front-rear direction of the cold plate 32. As a result, the refrigerant that has flowed through the flow path FP of the second flow path section 58 flows into one of the plurality of grooves 62 and is diffused in the width direction. The inside of the grooves 62 also forms part of the refrigerant flow path FP.

[0036] The overall cross-sectional area of ​​the flow path FP across the multiple grooves 62 is set to be smaller than, for example, the flow path of the inlet 52, and even smaller than the cross-sectional area of ​​the flow path FP of the second flow path section 58. Therefore, compared to a structure in which the overall cross-sectional area of ​​the flow path FP across the multiple grooves 62 is larger than the cross-sectional area of ​​the flow path FP of the second flow path section 58, the flow velocity of the refrigerant flowing through the grooves 62 becomes faster.

[0037] The flow channels FP of the third flow channel 64 are continuous with the diffusion section 60. The flow channels FP of the third flow channel 64 are formed in a direction away from the heat receiving section 46, that is, upward.

[0038] In this embodiment, multiple flow channels FP are provided in the third flow channel section 64. In the example shown in Figure 6, two flow channels FP are provided in the third flow channel section 64, spaced apart in the width direction. Hereinafter, the flow channels FP of the third flow channel section 64 will be appropriately distinguished as flow channel FPR for the flow channel on the right side in the width direction and flow channel FPL for the flow channel on the left side in the width direction. Flow channel FPR on the right side in the width direction is formed upward from the position of the right end of the groove 62 in the width direction, and flow channel FPL on the left side in the width direction is formed upward from the position of the left end of the groove 62 in the width direction.

[0039] The flow path FP of the outlet section 66 is continuous with the flow path FPR on the right side in the width direction of the third flow path section 64. Specifically, the flow path FP of the outlet section 66 is formed to extend forward from the flow path FPR, then curves to the right in the width direction, and then curves to the rear. The flow path FPR on the left side in the width direction of the third flow path section 64 merges with this rearward-facing portion.

[0040] The flow path FP of the outlet section 66 is bent to the left in the width direction from the portion formed toward the rear, and then bent again toward the rear. The flow path FP of the outlet section 66 is parallel to the heat receiving surface 48 along its entire length.

[0041] As shown in Figure 3, the outlet section 66 has an outlet 68 that opens into the opening surface 44. The outlet 68 is continuous with the flow path FP in the outlet section 66 of the flow path block 38. Similar to the inlet 54, a pipe 72 is connected to the outlet 68 via a connector 80. The pipe 72 connected to the inlet 54 and the pipe 72 connected to the outlet 68 are parallel to each other at the connection portions to the inlet 54 and the outlet 68, respectively.

[0042] As shown in Figure 3, the flow path FP at the outlet 66 is at the same height from the heat receiving surface 48, i.e., the vertical position of the liquid cooling module 30, along its entire length, as the flow path FP at the inlet 52. The height from the heat receiving surface 48 is also the position in the direction normal to the heat receiving surface 48.

[0043] Here, "the same" height from the heat receiving surface 48 means that, when viewing the liquid cooling module 30 in the width direction, the flow path FP of the inlet 52 and the flow path FP of the outlet 66 partially or completely overlap in the height direction. For example, in the example shown in Figure 5, the flow path FP of the inlet 52 and the flow path FP of the outlet 66 have the same cross-sectional shape, and the center of the opening of the inlet 52 and the center of the opening of the outlet 66 are at the same height. When viewed in the width direction, the flow path FP of the inlet 52 and the flow path FP of the outlet 66 completely overlap in the height direction.

[0044] Furthermore, the flow path FP of the inlet section 52 and the flow path FP 66 of the outlet section are at the same height from the heat receiving surface 48 as the flow path FP of the first flow path section 56. As shown in Figure 4, the flow path FP of the inlet section 52 and the flow path FP of the outlet section 66 are positioned in a plan view, avoiding the flow path FP of the first flow path section 56. Specifically, while the flow path FP of the first flow path section 56 is located in the center of the liquid cooling module 30, the flow path FP of the inlet section 52 and the flow path FP of the outlet section 66 are arranged along the outer circumference of the liquid cooling module 30. A portion of the flow path FP of the inlet section 52 and a portion of the flow path FP of the outlet section 66 surround the flow path FP of the first flow path section 56 (a fan-shaped flow path FP) in a plan view.

[0045] Throughout the liquid cooling module 30, the coolant flow path FP is introduced from the inlet 54 and discharged from the outlet 68, folding back from the front to the rear within the liquid cooling module 30. Both the inlet 54 and the outlet 68 are formed in the opening surface 44.

[0046] Thus, the flow path FP within the cold plate 32 has portions formed in the depth, width, and height directions, and has a three-dimensional structure.

[0047] As shown in Figure 3, the inlet 54 and outlet 68 open into the opening surface 44 of the liquid cooling module 30. Furthermore, the inlet 54 and outlet 68 are at the same height from the heat receiving surface 48.

[0048] As shown in Figure 1, the pipe 72 connected to the inlet 54 of the liquid cooling module 30R on the right side in the width direction acts as an introduction pipe 74. The refrigerant is introduced from outside the electronic equipment 10 into the liquid cooling module 30R through the introduction pipe 74.

[0049] The piping 72 connected to the outlet 68 of the liquid cooling module 30L acts as a discharge pipe 78. The liquid coolant inside the liquid cooling module 30L is discharged to the outside of the electronic equipment 10 through the discharge pipe 78.

[0050] A pipe 72 connects the outlet 68 of the liquid cooling module 30R on the right side in the width direction to the inlet 54 of the liquid cooling module 30L, and this pipe 72 acts as a transfer pipe 76. Liquid refrigerant is discharged from the outlet 68 of the liquid cooling module 30R through the transfer pipe 76 and sent to the inlet 54 of the liquid cooling module 30L, where it is introduced into the liquid cooling module 30L. The transfer pipe 76 functions as a discharge pipe for the liquid cooling module 30R and as an inlet pipe for the liquid cooling module 30L.

[0051] Both the liquid cooling module 30R and the liquid cooling module 30L are positioned with their opening surfaces 44 facing backward. The inlet pipe 74, transfer pipe 76, and discharge pipe 78 are all positioned on the rear side of the liquid cooling modules 30R and 30L, without passing through the front side. In other words, the inlet pipe 74, transfer pipe 76, and discharge pipe 78 are positioned to avoid the space between the fan 18 and the DIMM 20.

[0052] Next, the operation of this embodiment will be explained.

[0053] Liquid refrigerant is introduced into the liquid cooling module 30 from the inlet 54. This refrigerant flows inside the liquid cooling module 30 from the flow path FP of the inlet 52 to the flow path FP of the first flow path section 56. The flow path FP of the first flow path section 56 is fan-shaped, and the refrigerant spreads in the front-rear direction according to the shape of the flow path FP of the first flow path section 56. Furthermore, the refrigerant flows through the flow path FP of the second flow path section 58. Since the flow path FP of the second flow path section 58 extends toward the heat receiving surface 48, the refrigerant flows toward the heat receiving surface.

[0054] Furthermore, the refrigerant flows through the flow path FP of the diffusion section 60. Since the flow path FP of the diffusion section 60 has multiple grooves 62, the refrigerant flows into one of the multiple grooves 62 and spreads out in the width direction. Therefore, the refrigerant is diffused in the front-rear direction and width direction in the diffusion section 60. Since the diffusion section 60 is provided in the heat receiving section 46, the heat from the CPU 22 is transferred to the refrigerant via the heat receiving section 46, and the CPU 22 is cooled.

[0055] The refrigerant then flows away from the heat receiving section 46 through the flow path FP of the third flow path section 64. The refrigerant then flows through the flow path FP of the outlet section 66 and is discharged to the outside of the liquid cooling module 30 from the outlet 68.

[0056] In this manner, the refrigerant is diffused in the front-to-back and width directions within the heat receiving section 46 of the liquid cooling module 30. Therefore, compared to a structure in which the refrigerant is not diffused, the heat of the CPU 22 can be efficiently absorbed by the refrigerant. For example, compared to a so-called air-cooled cooling system that cools the CPU 22 using cooling air, this embodiment allows for efficient cooling of the object to be cooled by liquid cooling.

[0057] In this embodiment, the refrigerant flow path FP is diffused by the flow path FP of the diffusion section 60 inside the liquid cooling module 30 and then folded back. That is, although the direction in which the refrigerant flows in from the rear inlet 54 is forward, the flow path FP is folded back in the rear direction inside the liquid cooling module 30, and the refrigerant flows out from the rear outlet 68. By folding the flow path FP in this way, a structure is realized in which the inlet 54 and the outlet 68 can be formed on the same surface, i.e., the opening surface 44.

[0058] The flow path FP at the inlet 52 and the flow path FP at the outlet 66 are at the same height from the heat receiving surface 48. In contrast, in a structure where the flow path FP at the inlet 52 and the flow path FP at the outlet 66 are at different heights from the heat receiving surface 48, the height occupied by the flow path FP when the liquid cooling module 30 is viewed in the width direction becomes higher. In this embodiment, since the height occupied by the flow path FP is low at the inlet 52 and the outlet 66 when viewed in the width direction, the height dimension of the liquid cooling module 30 can be reduced.

[0059] In particular, in this embodiment, when viewing the liquid cooling module 30 in the width direction, the flow path FP at the inlet 52 and the flow path FP at the outlet 66 overlap overall in the height direction. Therefore, the height dimension of the liquid cooling module 30 can be made smaller compared to a structure in which the flow path FP at the inlet 52 and the flow path FP at the outlet 66 partially overlap in the height direction.

[0060] Furthermore, the fact that the flow path FP at the inlet 52 and the flow path FP at the outlet 66 are at the same height from the heat receiving surface 48 can be visually confirmed from the appearance of the liquid cooling module 30 as the inlet 54 and outlet 68 being at the same height.

[0061] In the case of a server, which is an example of an electronic device 10 equipped with a liquid cooling module 30, the height of the chassis 12 may be set to a height specified by a standard. For example, in the case of a rack-mount server installed in a rack, the chassis 12 may be within a height range of 1U, where 1U = 44.45 mm is used as the unit. In this case, it is difficult to place a liquid cooling module, which has a greater height, inside a chassis 12 with a height of 1U. In particular, in electronic devices with a structure in which various components and materials are densely mounted inside the chassis 12, it is difficult to secure space inside the chassis 12 to mount a liquid cooling module.

[0062] In contrast, the liquid cooling module 30 of this embodiment can be placed in a chassis 12 with a height of 1U by reducing its height. In other words, an electronic device 10 can be obtained in which a structure that can efficiently cool the CPU 22, which is the target of cooling, by liquid cooling is realized in a chassis 12 with a low height.

[0063] In this embodiment, both the flow path FP at the inlet 52 and the flow path FP at the outlet 66 are parallel to the heat receiving surface 48. In contrast, for example, in a structure where the flow path FP at the inlet 52 is inclined with respect to the heat receiving surface 48, the height of the liquid cooling module increases due to the inclination of the flow path FP. Similarly, even if the flow path FP at the outlet 66 is inclined with respect to the heat receiving surface 48, the height of the liquid cooling module increases due to the inclination of the flow path FP. In this embodiment, since the flow path FP at the inlet 52 and the flow path FP at the outlet 66 are parallel to the heat receiving surface 48, the height dimension of the liquid cooling module 30 does not increase due to the inclination of the flow path FP, and it is possible to reduce the height dimension of the liquid cooling module 30.

[0064] The flow path FP of the first flow path section 56 spreads out in a fan shape, so the refrigerant spreads and flows in the direction of this spread, and refrigerant stagnation is suppressed. In addition, the flow path FP of the first flow path section 56 is inclined upwards, gradually moving away from the heat receiving surface 48 as it spreads out in a fan shape. Due to this inclination, resistance acts on the flow of the refrigerant flowing through the flow path FP of the first flow path section 56. The length of the inclined portion of the flow path FP of the first flow path section 56 is long in the center of the fan shape and short on both sides of the fan shape (both sides in the front-rear direction of the liquid cooling module 30). Therefore, the resistance to the flow of the refrigerant is large in the center of the fan shape and small on both sides of the fan shape. In the center of the fan shape, the refrigerant flows in linearly from the flow path FP of the inlet section 52, so the flow velocity is high in the initial stages of flow. In contrast, the flow velocity is relatively slower in the initial stages of flow on both sides of the fan shape. However, since the inclined portion is long in the center of the fan shape, the flow resistance is greater than on both sides. This ensures that the refrigerant flow velocity is uniform throughout the flow path FP of the first flow path section 56. If the refrigerant flow velocity differs locally, there is a higher possibility of stagnation and vortices occurring in the flow, but in this embodiment, stagnation and vortex generation of the refrigerant flowing through the flow path FP of the first flow path section 56 can be suppressed.

[0065] The flow path FP of the second flow path section 58 is formed toward the center of the heat receiving surface 48. Since the center of the heat receiving surface 48 is the position in contact with the CPU 22, which is an example of a cooling target, it is possible to efficiently transfer the heat from the CPU 22 to the coolant flowing through the flow path FP.

[0066] In this embodiment, there are multiple (two) flow channels FP in the third flow channel section 64. Compared to a structure in which there is only one flow channel FP in the third flow channel section 64, the refrigerant flowing through the flow channel FP of the diffusion section 60 can be efficiently moved to the flow channel FP of the outlet section 66.

[0067] In particular, in this embodiment, the flow path FP of the third flow path section 64 consists of two flow paths: a flow path FPR on the right side in the width direction and a flow path FPL on the left side in the width direction. Therefore, in the diffusion section 60, the refrigerant diffused in the width direction can be moved to the flow path FP of the outlet section 66 from both the right and left sides in the width direction.

[0068] In this embodiment, as shown in Figure 5, the height position of the flow path FP in the first flow path section 56 is the same as the height position of the flow path FP in the inlet section 52 and the flow path FP in the outlet section 66. Therefore, compared to a structure in which the height position of the flow path FP in the first flow path section 56 is different from the height position of the flow path FP in the inlet section 52 and the flow path FP in the outlet section 66, it is possible to shorten the height dimension of the liquid cooling module 30.

[0069] Furthermore, in a plan view, the flow path FP of the inlet section 52 and the flow path FP of the outlet section 66 are arranged along the outer circumference of the liquid cooling module 30. This realizes a structure in which the flow path FP of the first flow path section 56 can be positioned in the center of the liquid cooling module 30 in a plan view.

[0070] The electronic device 10 of this embodiment has a fan 18, as shown in Figure 1. The airflow generated by the fan 18 can cool the DIMM 20.

[0071] The inlet pipe 74, transfer pipe 76, and discharge pipe 78 are positioned to avoid the space between the fan 18 and the DIMM 20. Since the inlet pipe 74, transfer pipe 76, and discharge pipe 78 are not located between the fan 18 and the DIMM 20, it is possible to position the fan 18 and the DIMM 20 in close proximity, allowing the DIMM 20 to be efficiently cooled by the airflow from the fan 18. Furthermore, by positioning the fan 18 and the DIMM 20 in close proximity, it is possible to arrange various components and parts at a high density inside the enclosure 12.

[0072] Furthermore, the transfer pipe 76 is a pipe through which refrigerant is discharged from the liquid cooling module 30R, and this refrigerant is often at a higher temperature than the refrigerant introduced into the liquid cooling module 30R. Similarly, the discharge pipe 78 is a pipe through which refrigerant is discharged from the liquid cooling module 30L, and this refrigerant is often at a higher temperature than the refrigerant introduced into the liquid cooling module 30R and the refrigerant introduced into the liquid cooling module 30L. In this embodiment, the air generated by the fan 18 does not pass through the transfer pipe 76 and discharge pipe 78 through which such high-temperature refrigerant flows, thus suppressing the temperature rise of the air and efficiently cooling the DIMM 20.

[0073] In particular, this embodiment has two liquid cooling modules 30R and 30L, each with an inlet 54 and an outlet 68 opening to the same opening surface 44. The two liquid cooling modules 30R and 30L are arranged with their respective opening surfaces 44 facing the same direction (rearward in the example of Figure 1). Therefore, a structure can be easily realized in which the outlet 68 of liquid cooling module 30R and the inlet 54 of liquid cooling module 30L are connected by a transfer pipe 76 on the side where the opening surface 44 is formed.

[0074] Although one embodiment of the technology disclosed in this application has been described above, the technology disclosed in this application is not limited to the above, and it is of course possible to implement it in various modified forms without departing from its spirit.

[0075] Furthermore, the following additional information is disclosed regarding one embodiment of the technology disclosed in this application as described above. (Note 1) A heat receiving section having a heat receiving surface that receives heat from the object to be cooled, The inlet portion includes an inlet through which a liquid refrigerant that undergoes heat exchange in the heat receiving section flows, and a flow path is formed through which the refrigerant flowing in from the inlet flows, The flow path is continuous with the inlet and is formed as a first flow path that spreads out in a fan shape when viewed in the direction normal to the heat receiving surface, The aforementioned flow path is continuous with the first flow path section and is formed in the normal direction toward the heat receiving section, The heat receiving section includes a diffusion section in which a plurality of grooves are formed that are continuous with the flow path of the second flow path and spread along the surface opposite to the heat receiving surface, The flow path is continuous with the plurality of grooves and is formed in the direction normal to the flow path and in a direction away from the heat receiving portion, The outlet section is provided with an outlet for discharging the refrigerant, and the flow path is continuous from the third flow path section to the outlet, It has, A liquid cooling module in which the flow path at the inlet and the flow path at the outlet are at the same height from the heat receiving surface. (Note 2) The liquid cooling module according to Appendix 1, wherein the inlet and outlet open to the same opening surface. (Note 3) The liquid cooling module according to Appendix 1 or Appendix 2, wherein the refrigerant flow path at the inlet and the refrigerant flow path at the outlet are parallel to the heat receiving surface. (Note 4) The liquid cooling module according to any one of the appendices 1 to 3, wherein the bottom surface of the first flow channel is inclined in a direction that gradually moves away from the heat receiving surface as it spreads out in the fan shape. (Note 5) The liquid cooling module according to any one of the appendices 1 to 4, wherein the flow channel of the second flow channel is formed toward the center of the heat receiving surface. (Note 6) The liquid cooling module according to any one of the appendices 1 to 5, wherein the third flow channel section comprises a plurality of the flow channels. (Note 7) The liquid cooling module according to any one of the appendices 1 to 6, wherein the height position of the flow channel in the first flow channel section from the heat receiving surface is the same as that of the flow channel in the inlet section and the flow channel in the outlet section. (Note 8) A heat receiving section having a heat receiving surface that receives heat from the object to be cooled, The inlet portion includes an inlet through which a liquid refrigerant that undergoes heat exchange in the heat receiving section flows, and a flow path is formed through which the refrigerant flowing in from the inlet flows, The flow path is continuous with the inlet and is formed as a first flow path that spreads out in a fan shape when viewed in the direction normal to the heat receiving surface, The flow path is continuous with the first flow path and is formed toward the heat receiving section, The heat receiving section includes a diffusion section in which a plurality of grooves are formed that are continuous with the flow path of the second flow path and spread along the surface opposite to the heat receiving surface, The flow path is a third flow path portion formed in a direction that is continuous with the plurality of grooves and separates from the heat receiving portion, The outlet section is provided with an outlet for discharging the refrigerant, and the flow path is continuous from the third flow path section to the outlet, It has, A liquid cooling module in which the flow path at the inlet and the flow path at the outlet are at the same height from the heat receiving surface, The electronic component to be cooled is positioned in contact with the heat receiving surface, A powerful electronic device. (Note 9) A fan that generates airflow to cool the second object to be cooled, A pipe is positioned to avoid the space between the fan and the second object to be cooled, and discharges the refrigerant from the outlet, Electronic equipment as described in Appendix 8, having the following characteristics. (Note 10) The liquid cooling modules comprises a plurality of inlets and outlets that open to the same opening surface, The electronic device according to Appendix 8 or Appendix 9, wherein multiple liquid cooling modules are arranged with the opening surfaces facing the same direction. [Explanation of symbols]

[0076] 10 Electronic equipment 12 cabinets 14 circuit boards 16 HDD 18 Fans 20 DIMMs (an example of a second cooling target) 22 CPUs (an example of items to be cooled) 24 PCI 26 PSU 30 liquid cooling modules 32 Cold Plates 34 Base 36 Cover 38 Flow channel block 40 Fasteners 42 Convex part 44 Opening surface 46 Heat receiving part 48 Heat receiving surface 50 Heat transfer components 52 Entrance 54 Entrance 56 First channel section 58 Second flow path section 60 Diffusion section 62 Groove 64 Third flow path section 66 Exit section 68 Exit 72 Piping 74 Introductory tube 76 Transfer pipe 78 Discharge pipe 80 connectors

Claims

1. A heat receiving section having a heat receiving surface that receives heat from the object to be cooled, The inlet portion includes an inlet through which a liquid refrigerant that undergoes heat exchange in the heat receiving section flows, and a flow path is formed through which the refrigerant flowing in from the inlet flows, The flow path is continuous from the inlet and is formed as a first flow path that spreads out in a fan shape when viewed in the direction normal to the heat receiving surface, The aforementioned flow path is continuous with the first flow path section and is formed in the normal direction toward the heat receiving section, The heat receiving section includes a diffusion section in which a plurality of grooves are formed that are continuous with the flow path of the second flow path and spread along the surface opposite to the heat receiving surface, The flow path is continuous with the plurality of grooves and is formed in the direction normal to the flow path and in a direction away from the heat receiving portion, The outlet section is provided with an outlet for discharging the refrigerant, and the flow path is continuous from the third flow path section to the outlet, It has, A liquid cooling module in which, when the direction parallel to the normal direction is defined as the height, the flow path at the inlet and the flow path at the outlet are at the same height from the heat receiving surface.

2. The liquid cooling module according to claim 1, wherein the refrigerant flow path at the inlet and the refrigerant flow path at the outlet are parallel to the heat receiving surface.

3. The liquid cooling module according to claim 1 or claim 2, wherein the bottom surface of the first flow channel is inclined in a direction that gradually moves away from the heat receiving surface as it spreads out in the fan shape.

4. The liquid cooling module according to claim 1 or 2, wherein the flow path in the second flow path section is formed toward the center of the heat receiving surface.

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