Cold plate

Abstract

A cold plate 1 comprises: an internal space 101 through which a refrigerant flows; a laminate 20 disposed in the internal space 101 and including a first layer 40 and a second layer 50 which are laminated; and a plurality of fins 70 disposed in the internal space 101. The first layer 40 has a first main flow path 41A through which the refrigerant flows, and the second layer 50 has a cross flow path 51 which communicates with the first main flow path 41A and through which the refrigerant flows.

Description

Cold plate

[0001] The present invention relates to a cold plate that contacts a heat source and performs heat exchange between a refrigerant flowing in an internal space and the heat source. For designated countries where incorporation by reference is permitted, the contents described in Japanese Patent Application No. 2024-189940 filed in Japan on October 29, 2024, and Japanese Patent Application No. 2025-035344 filed in Japan on March 6, 2025, are incorporated herein by reference and made part of the description of this specification.

[0002] A laminated heat exchanger is known that includes first and second punching plates alternately laminated such that the openings are offset by a half pitch, and the refrigerant flows linearly as a whole while meandering through each plate in the vertical direction (see, for example, Patent Document 1).

[0003] Japanese Unexamined Patent Application Publication No. 2020-96123

[0004] There are cases where a high-heat-generating semiconductor device and a low-heat-generating semiconductor device are mounted on the same substrate. When cooling a plurality of semiconductor devices with different heat generation amounts using a single laminated heat exchanger, there is a problem that excessive cooling performance occurs and the pressure loss increases.

[0005] The problem to be solved by the present invention is to provide a cold plate capable of optimizing cooling performance and pressure loss.

[0006] [1] Aspect 1 of the present invention includes an internal space through which a refrigerant flows, a laminate including a first layer and a second layer, a laminate disposed in the internal space, and a plurality of fins disposed in the internal space. The first layer has a first flow path through which the refrigerant flows, and the second layer communicates with the first flow path and has a second flow path through which the refrigerant flows.

[0007] [2] Aspect 2 of the present invention is the cold plate according to Aspect 1, wherein the cold plate may include a case having the internal space, and the laminate and the plurality of fins are housed in the case.

[0008] [3] Embodiment 3 of the present invention is a cold plate of Embodiment 2 in which the plurality of fins are provided on the bottom plate of the case and the cold plate is integrally formed with the bottom plate.

[0009] [4] Embodiment 4 of the present invention is a cold plate according to Embodiment 2 or 3, wherein the case has an opening formed in the bottom plate of the case, and the laminate is a cold plate exposed from the bottom plate through the opening.

[0010] [5] Embodiment 5 of the present invention is a cold plate according to Embodiment 4, wherein the laminate is a cold plate that protrudes from the bottom plate through the opening.

[0011] [6] Embodiment 6 of the present invention is a cold plate of embodiment 4 or 5, wherein the laminate is a cold plate having a flange portion that joins with the bottom plate around the opening.

[0012] [7] Embodiment 7 of the present invention is a cold plate according to Embodiment 6, wherein the laminate comprises a heat exchange section having a flow path including the first flow path and the second flow path, and a cover section that is exposed from the bottom plate through the opening and covers the heat exchange section, and the flange section may be a cold plate that protrudes radially outward from the cover section.

[0013] [8] Embodiment 8 of the present invention is a cold plate in any one of embodiments 1 to 7, wherein the laminate comprises a heat exchange section having a flow path including the first flow path and the second flow path, and the laminate is a cold plate having a distribution hole that penetrates the first and second layers and communicates with the heat exchange section, through which the refrigerant flows into the heat exchange section.

[0014] [9] Embodiment 9 of the present invention is a cold plate in any one of embodiments 1 to 8, wherein the laminate comprises a heat exchange section having a flow path including the first flow path and the second flow path, and the laminate comprises a confluence hole that penetrates the first and second layers and communicates with the heat exchange section, through which the refrigerant flows out of the heat exchange section.

[0015]

[10] Embodiment 10 of the present invention is a cold plate in any one of embodiments 1 to 9, wherein the cold plate has an inlet through which the refrigerant flows into the internal space and an outlet through which the refrigerant flows out of the internal space, and the laminate is a cold plate located upstream of the plurality of fins in the direction of flow of the refrigerant.

[0016]

[11] Embodiment 11 of the present invention is a cold plate in any one of embodiments 1 to 10, wherein the first layer has a first flow path through which the refrigerant flows in a first direction, and a third flow path through which the refrigerant flows in the first direction and which is located at a different position from the first flow path in a second direction intersecting the first direction, and the second flow path is in communication with the first flow path and the third flow path and through which the refrigerant flows in the second direction.

[0017]

[12] Embodiment 12 of the present invention is a cold plate in any one of embodiments 1 to 11, wherein the laminate is a cold plate comprising a plurality of first layers and a plurality of second layers.

[0018]

[13] Embodiment 13 of the present invention is a cold plate in any one of embodiments 1 to 12 in which the plurality of fins include a plurality of plate-shaped fins arranged parallel to each other.

[0019] In this invention, since a laminate and multiple fins are arranged in the internal space through which the refrigerant flows, the cooling performance and pressure loss of the cold plate can be optimized.

[0020] Figure 1 is a cross-sectional view of a cold plate in an embodiment of the present invention. Figure 2 is a cross-sectional view along line II-II in Figure 1. Figure 3 is a cross-sectional view showing a laminate in an embodiment of the present invention, along line III-III in Figure 2. Figures 4(a) to 4(d) are cross-sectional views showing the layer structure of a laminate in an embodiment of the present invention, where Figure 4(a) is a cross-sectional view along line IVA-IVA in Figure 3, Figure 4(b) is a cross-sectional view along line IVB-IVB in Figure 3, Figure 4(c) is a cross-sectional view along line IVC-IVC in Figure 3, and Figure 4(d) is a cross-sectional view along line IVD-IVD in Figure 3. Figure 5 is a plan view showing the channel forming portion of the first layer in an embodiment of the present invention, and is an enlarged view corresponding to part A in Figures 4(a) to 4(c). Figure 6 is a plan view showing the channel forming portion of the second layer in an embodiment of the present invention, and is an enlarged view corresponding to part A in Figures 4(a) to 4(c). Figure 7 is a diagram illustrating the flow of refrigerant in an embodiment of the present invention, and is a plan view showing the flow paths of the first and second layers superimposed on each other, and is an enlarged view corresponding to part A in Figures 4(a) to 4(c). Figure 8 is a partial cross-sectional view of the laminate in an embodiment of the present invention, and is a view of the laminate cut along the line VIII-VIII in Figure 4(b). Figure 9 is a cross-sectional view showing a cold plate in another embodiment of the present invention. Figure 10 is a cross-sectional view showing a cold plate in yet another embodiment of the present invention. Figure 11 is a cross-sectional view showing a cold plate in yet another embodiment of the present invention. Figure 12 is a cross-sectional view along the line XII-XII in Figure 11. Figure 13 is a cross-sectional view showing a cold plate in yet another embodiment of the present invention.

[0021] Embodiments of the present invention will be described below with reference to the drawings.

[0022] Figure 1 is a cross-sectional view of the cold plate 1 in this embodiment, and Figure 2 is a cross-sectional view along the line II-II in Figure 1.

[0023] As shown in Figures 1 and 2, the cold plate 1 in this embodiment is a heat exchanger (cooler) that cools semiconductor devices 110 and 120 mounted on a substrate 100. Specifically, the cold plate 1 comes into contact with the semiconductor devices 110 and 120, which are heat sources, and cools the semiconductor devices 110 and 120 by exchanging heat between the refrigerant circulating in the internal space 101 and the semiconductor devices 110 and 120. Specific examples of refrigerants include, for example, water, glycol-based aqueous solutions (ethylene glycol aqueous solution, propylene glycol aqueous solution, etc.), and fluorine-based inert liquids. A gas may also be used as the refrigerant.

[0024] The two semiconductor devices 110 and 120 are devices equipped with semiconductor chips that generate different amounts of heat. While not particularly limited, one semiconductor device 110 is a high-heat-generating semiconductor device such as an AI server, supercomputer, or CPU / GPU for a mainframe. In contrast, the other semiconductor device 120 is a low-heat-generating semiconductor device such as a memory device like an HBM (High Bandwidth Memory). The amount of heat generated by this semiconductor device 120 is relatively small compared to the amount of heat generated by semiconductor device 110. In this embodiment, semiconductor device 120 is an HBM with a relatively large number of layers, and the height of semiconductor device 120 is greater than the height of semiconductor device 110.

[0025] The heat source (object to which heat exchange occurs) is not limited to the semiconductor devices 110 and 120 described above. Furthermore, the number of semiconductor devices mounted on the substrate 100 is not particularly limited.

[0026] The cold plate 1 comprises a case 10, a laminate 20, and a plurality of fins 70. The refrigerant passes through the internal space 101 of the case 10. The laminate 20 and fins 70 are arranged in this internal space 101. The laminate 20 and fins 70 exchange heat with the refrigerant passing through the internal space 101.

[0027] In the internal space 101, the laminate 20 is arranged to correspond to the high-heat-generating semiconductor device 110, while the multiple fins 70 are arranged to correspond to the low-heat-generating semiconductor device 120. In other words, the cold plate 1 of this embodiment has two heat exchange sections. The laminate 20, which functions as the first heat exchange section, has relatively high cooling performance. In contrast, the multiple fins 70, which function as the second heat exchange section, have lower cooling performance compared to the cooling performance of the laminate 20. In this embodiment, the laminate 20, which has high cooling performance, is assigned to cooling the high-heat-generating semiconductor device 110, and the fins 70, which have low cooling performance, are assigned to cooling the low-heat-generating semiconductor device 120.

[0028] The case 10 comprises a bottom plate 11 and a lid 12. The bottom plate 11 is a plate-shaped member made of a metal material having good thermal conductivity. While not particularly limited, specific examples of the metal material constituting the bottom plate 11 include, for example, copper, aluminum, and alloys thereof. A plurality of fins 70 are provided on the bottom plate 11. The plurality of fins 70 are positioned on the bottom plate 11 to correspond to low-heat-generating semiconductor devices 120. The bottom plate 11 and the plurality of fins 70 are integrally formed.

[0029] Each fin 70 is a plate-shaped projection that protrudes from the upper surface of the bottom plate 11 toward the internal space 101. Each fin 70 extends along the direction (the +X direction in Figures 1 and 2) in which the refrigerant passing through the internal space 101 of the case 10 moves from upstream to downstream. Multiple fins 70 are arranged parallel to each other with spacing between them. The number of fins 70 provided on the cold plate 1 is not particularly limited.

[0030] The shape of each fin 70 is not limited to those described above. For example, the shape of the fin 70 may be a columnar projection, a pin-shaped projection, or a needle-shaped projection. Alternatively, an offset fin, a corrugated fin, or a folded fin may be used as the fin 70.

[0031] Furthermore, an opening 111 is formed in the bottom plate 11 of the case 10. This opening 111 is formed in the bottom plate 11 at a position corresponding to the high-heat-generating semiconductor device 110. As will be described later, a laminate 20 is inserted into this opening 111.

[0032] The lid 12 of the case 10 comprises an upper plate 13 facing the bottom plate 11 and a cylindrical portion 14 to which the upper plate 13 is connected so as to close the upper opening. This lid 12 is made of a metal material or a resin material. Although not particularly limited, the metal material that makes up the lid 12 can be the same as the metal material that makes up the bottom plate 11 described above. On the other hand, examples of resin materials that make up the lid 12 include polyphenylene sulfide (PPS), ABS resin, nylon, polypropylene, polybutylene terephthalate, and polycarbonate. The upper plate 13 and the cylindrical portion 14 are integrally formed.

[0033] The internal space 101 is formed by closing the opening on the lower side of the lid 12 with the bottom plate 11. The joint between the lid 12 and the bottom plate 11 is sealed to prevent refrigerant from leaking from the case 10. The top plate 13 of the lid 12 has an inlet 121 and an outlet 122. The inlet 121 is located at one end of the top plate 13 (the left end in Figure 1), and the outlet 122 is located at the other end of the top plate 13 (the right end in Figure 1).

[0034] In the internal space 101 of case 10, the laminate 20 is positioned near the inlet 121 (on the -X side in the figure), while the multiple fins 70 are positioned near the outlet 122 (on the +X side in the figure). In other words, in the direction of coolant flow, the laminate 20 is positioned upstream of the multiple fins 70. This makes it possible to improve the cooling efficiency of the high-heat-generating semiconductor device 110 by the laminate 20.

[0035] The installation positions of the inlet 121 and outlet 122 are not particularly limited to those described above. For example, the inlet 121 may be placed on one side of the cylindrical portion 14 (the left side in Figure 1). The outlet 122 may be placed on the other side of the cylindrical portion 14 (the right side in Figure 1).

[0036] Figure 3 is a cross-sectional view of the laminate 20 in this embodiment, and is a view along the line III-III in Figure 2. Figures 4(a) to 4(d) are cross-sectional views of the layer structure of the laminate 20 in this embodiment, where Figure 4(a) is a cross-sectional view along IVA-IVA in Figure 3, Figure 4(b) is a cross-sectional view along the line IVB-IVB in Figure 3, Figure 4(c) is a cross-sectional view along the line IVC-IVC in Figure 3, and Figure 4(d) is a cross-sectional view along the line IVD-IVD in Figure 3. Figure 5 is a plan view of the channel forming portion 31 of the first layer 40 in this embodiment, and is an enlarged view corresponding to portion A in Figures 4(a) to 4(c). Figure 6 is a plan view of the channel forming portion 31 of the second layer 50 in this embodiment, and is an enlarged view corresponding to portion A in Figures 4(a) to 4(c). Figure 7 is a diagram illustrating the flow of refrigerant in this embodiment, and is a plan view showing the flow paths 41, 51 of the first and second layers 40, 50 superimposed on each other, and is an enlarged view corresponding to part A in Figures 4(a) to 4(c). Figure 8 is a partial cross-sectional view of the laminate 20 in this embodiment, and is a view of the laminate 20 when cut along the line VIII-VIII in Figure 4(b). The cross-section in Figure 8 is also the cross-section when the laminate 20 is cut along the line VIII-VIII in Figure 7.

[0037] As shown in Figure 3, the laminate 20 comprises a heat exchange section 21, a cover section 22, and a flange section 23. The heat exchange section 21 is the portion in which the parallel flow channels 41 and the intersecting flow channels 51, described later, are formed. The cover section 22 covers the lower part of the heat exchange section 21. A distribution hole 24 and a merging hole 25 are interposed between the heat exchange section 21 and the cover section 22. The flange section 23 protrudes radially outward from the upper end of the cover section 22. The heat exchange section 21 has basically the same configuration as that described in Japanese Patent Application Publication No. 2024-115132. The configuration of the laminate 20 is not particularly limited to the following, as long as it is a laminate of a first layer having a first flow channel and a second layer having a second flow channel communicating with the first flow channel.

[0038] This laminate 20 is formed by stacking and joining multiple layers. The multiple layers constituting this laminate 20 include multiple channel-forming layers 30 and one bottom layer 60. Each channel-forming layer 30 has a channel-forming section 31 on which parallel channels 41 or intersecting channels 51, described later, are formed. The heat exchange section 21 is formed by stacking the channel-forming sections 31 of the multiple channel-forming layers 30. The bottom layer 60 is stacked below the stacked multiple channel-forming layers 30. Although not particularly limited, each channel-forming layer 30 has a thickness of, for example, about 0.2 mm. These multiple channel-forming layers 30 include three types of channel-forming layers 30A to 30C.

[0039] The channel-forming layer 30A is a channel-forming layer that constitutes the portion of the laminate 20 in which the heat exchange portion 21 is not covered by the cover portion 22. As shown in Figure 4(a), this channel-forming layer 30A has a channel-forming portion 31, but does not have a distribution hole 24, a confluence hole 25, and a flange portion 23.

[0040] The channel-forming layer 30B is a channel-forming layer that constitutes the portion of the laminate 20 in which the heat exchange portion 21 is covered by the cover portion 22. As shown in Figure 4(b), this channel-forming layer 30B has distribution holes 24 and confluence holes 25 in addition to the channel-forming portion 31. This channel-forming layer 30B is larger than the channel-forming layer 30A described above.

[0041] The channel-forming layer 30C is a channel-forming layer that constitutes the portion of the laminate 20 that includes the flange portion 23. As shown in Figure 4(c), this channel-forming layer 30C includes a channel-forming portion 31, a distribution hole 24, and a confluence hole 25, as well as a wide frame portion 32. This channel-forming layer 30C is larger than the channel-forming layer 30B described above.

[0042] As shown in FIG. 3, the distribution holes 24 and the confluence holes 25 penetrate through the flow path forming layers 30B and 30C that are overlapped with each other. The distribution holes 24 communicate with the flow path forming portions 31 of the flow path forming layers 30B and 30C. The refrigerant flows into the flow path forming portions 31 of the flow path forming layers 30B and 30C from these distribution holes 24. The confluence holes 25 also communicate with the flow path forming portions 31 of the flow path forming layers 30B and 30C. The refrigerant flows out from the flow path forming portions 31 of the flow path forming layers 30B and 30C into these confluence holes 25.

[0043] As shown in FIG. 4(d), the lowermost layer 60 is a simple plate-like layer in which the flow path forming portion 31, the distribution holes 24, and the confluence holes 25 are not formed. This lowermost layer 60 has the same size as the above-described flow path forming layer 30B. By this lowermost layer 60, the lower opening of the distribution hole 24 is blocked and the lower opening of the confluence hole 25 is blocked.

[0044] As shown in FIG. 1, this laminate 20 is installed in the case 10 in a state where the cover portion 22 is inserted into the opening 111 of the bottom plate 11 of the case 10. The flange portion 23 is joined to the portion around the opening 111 on the bottom plate 11, whereby the watertightness between the bottom plate 11 of the case 10 and the laminate 20 is ensured. Although not particularly limited, as a method of joining the flange portion 23 of the laminate 20 and the bottom plate 11 of the case 10, for example, diffusion bonding can be exemplified.

[0045] The tip of this cover portion 22 is exposed from the bottom plate 11, and the laminate 20 is in direct contact with the high-heat-generating semiconductor device 110 without passing through the bottom plate 11 of the case 10. Thereby, the cooling efficiency of the high-heat-generating semiconductor device 110 by the laminate 20 can be enhanced.

[0046] Furthermore, in the present embodiment, the tip of the cover portion 22 protrudes downward from the lower surface of the bottom plate 11 of the case 10. For this reason, it is not necessary to thicken the bottom plate 11 with respect to the semiconductor device 120 having a lower height than the semiconductor device 110, and the high-heat-generating semiconductor device 120 can be efficiently cooled.

[0047] As shown in FIG. 3, the cover portion 22 in the present embodiment has a concave shape that protrudes downward. The cover portion 22 has a U-shaped cross-sectional shape, although it is not particularly limited. Specifically, such a cover portion 22 is composed of the outer peripheral portions of a plurality (six in this example) of the flow path forming layers 30B (see FIG. 4(b)) and the lowermost layer 60.

[0048] This cover portion 22 includes a lower portion 222 and side portions 223. The lower portion 222 constitutes the lower end of the cover portion 22. The lower portion 222 is composed of the lowermost layer 60 and has a flat plate shape. As shown in FIG. 1, the lower portion 222 is interposed between the heat exchange portion 21 and the semiconductor device 110.

[0049] As shown in FIG. 3, the side portions 223 are disposed above the lower portion 222. The side portions 223 constitute the outer peripheral portion of the cover portion 22. The side portions 223 are composed of the outer peripheral portions of a plurality of flow path forming layers 30B (see FIG. 4(b)) and have a cylindrical shape. The side portions 223 surround the periphery of the heat exchange portion 21 between the lower portion 222 and the flange portion 23.

[0050] As shown in FIGS. 3 and 4(a) to 4(c), the plurality of flow path forming layers 30A to 30C described above include a plurality of first layers 40 and a plurality of second layers 50. As shown in FIG. 3, the plurality of first layers 40 and the plurality of second layers 50 are alternately laminated, and the lowermost layer 60 is stacked thereunder. These laminated layers 40, 50, 60 are joined to each other by, for example, diffusion bonding. Note that the method of fixing the layers 40, 50, 60 constituting the laminate 20 is not particularly limited to the above-described diffusion bonding.

[0051] Each of the layers 40, 50, and 60 before joining is a plate-shaped member made of a metallic material having good thermal conductivity. While not particularly limited, specific examples of the metallic materials constituting these layers 40, 50, and 60 include, for example, copper, aluminum, and alloys thereof. The parallel channels 41, distribution holes 24, and confluence holes 25 of the first layer 40 are formed by etching the plate-shaped member. Similarly, the intersecting channels 51, distribution holes 24, and confluence holes 25 of the second layer 50 are also formed by etching the plate-shaped member.

[0052] As shown in Figure 5, the first layer 40 has a flow path forming section 31 in which a plurality of parallel flow paths 41 are formed, each having a different position in the Y direction in the figure. Coolant flows through each of the parallel flow paths 41 toward the +X side in the figure.

[0053] Hereinafter, the end of the parallel flow path 41 closest to the inlet 121 of case 10 will be referred to as the "inlet end 411," and the end of the parallel flow path 41 closest to the outlet 122 will be referred to as the "outlet end 412." In other words, the inlet end 411 is the inlet side (the -X side in the figure) of the parallel flow path 41, and the outlet end 412 is the outlet side (the +X side in the figure) of the parallel flow path 41.

[0054] Each parallel flow path 41 includes two flow holes 42 and two occlusions 43. The flow holes 42 are holes that extend in the X direction in the figure and allow the refrigerant to flow in the X direction in the figure. Each flow hole 42 penetrates the first layer 40 in its thickness direction (Z direction in the figure). The occlusions 43 are portions that block the flow holes 42 and restrict the flow of the refrigerant in the X direction in the figure.

[0055] The multiple parallel channels 41 include a plurality of first main channels 41A and a plurality of second main channels 41B. The second main channels 41B are located at different positions from the first main channels 41A in the Y direction in the figure. Although not particularly limited, in this embodiment, the plurality of first main channels 41A and the plurality of second main channels 41B are arranged alternately in the Y direction in the figure. The first main channels 41A correspond to an example of the "first channel" in the embodiment of the present invention, and the second main channels 41B correspond to an example of the "third channel" in the embodiment of the present invention.

[0056] The location where the occlusion section 43 is provided in the first main channel 41A is different from the location where the occlusion section 43 is provided in the second main channel 41B. Specifically, in the first main channel 41A, the occlusion section 43 is provided at the outlet end 412 and in the portion other than both ends in the X direction in the figure (the midpoint in the X direction in the figure). On the other hand, in the second main channel 41B, the occlusion section 43 is provided at the inlet end 411 and in the portion other than both ends in the X direction in the figure (the midpoint in the X direction in the figure).

[0057] In the following, the closure portion 43 provided at the inlet end 411 of the parallel flow path 41 will be referred to as the "inlet closure portion 43a," and the closure portion 43 provided at the outlet end 412 of the parallel flow path 41 will be referred to as the "outlet closure portion 43b." Furthermore, the closure portions 43 provided in parts of the parallel flow path 41 other than both ends (inlet end 411 and outlet end 412) will be referred to as the "intermediate closure portion 43c." In addition, the intermediate closure portion 43c provided in the first main flow path 41A will be referred to as the "first intermediate closure portion 43d," and the intermediate closure portion 43c provided in the second main flow path 41B will be referred to as the "second intermediate closure portion 43e."

[0058] In this embodiment, the first main flow path 41A is provided with an outlet closure 43b and a first intermediate closure 43d, but does not have an inlet closure 43a. Therefore, refrigerant flows into the heat exchange section 21 via this first main flow path 41A. In contrast, the second main flow path 41B is provided with an inlet closure 43a and a second intermediate closure 43e, but does not have an outlet closure 43b. Therefore, refrigerant flows out of the heat exchange section 21 via this second main flow path 41B.

[0059] As shown in Figure 6, the second layer 50 has a flow path forming section 31 which has a plurality of intersecting flow paths (sub-flow paths) 51 whose positions in the X direction in the figure are different from each other. Coolant flows in the Y direction in the figure through each intersecting flow path 51. The intersecting flow paths 51 correspond to an example of the "second flow path" in the embodiment of the present invention.

[0060] Each intersecting flow path 51 includes a plurality of connection holes 52 and a plurality of disconnection portions 53. These connection holes 52 and disconnection portions 53 are arranged alternately in the Y direction in the figure. The connection holes 52 are holes that extend in the Y direction in the figure and allow the refrigerant to flow in the Y direction in the figure. Each connection hole 52 penetrates the second layer 50 in its thickness direction (Z direction in the figure). The disconnection portions 53 are portions that close off the connection holes 52 and restrict the flow of refrigerant in the Y direction in the figure.

[0061] As shown in Figures 7 and 8, each connection hole 52 is positioned to overlap with both the first main flow path 41A and the second main flow path 41B in a plan view. More specifically, one end of the connection hole 52 (the +Y side end in the figure) overlaps with the first main flow path 41A, and the other end of the connection hole 52 (the -Y side end in the figure) overlaps with the second main flow path 41B. As a result, each connection hole 52 (crossing flow path 51) is in communication with both the first main flow path 41A and the second main flow path 41B.

[0062] Therefore, the refrigerant can move through the connection hole 52 between one adjacent first main flow path 41A and one second main flow path 41B in the Y direction in the figure. Also, as shown in Figure 8, in a plan view, in the portion where the parallel flow path 41 and the connection hole 52 overlap (the portion where the parallel flow path 41 and the intersecting flow path 51 intersect), the refrigerant can move between the flow path forming portions 31 of all the first and second layers 40 and 50 of the laminate 20 in the thickness direction of the laminate 20 (the Z direction in the figure).

[0063] The flow of refrigerant in the heat exchange section 21, which is equipped with the parallel flow path 41 and the crossing flow path 51 described above, will be explained below with reference to Figures 7 and 8.

[0064] The refrigerant flows from the inlet end 411 into each of the first main flow paths 41A (flow F1 in Figure 7). This refrigerant then flows in the direction X in the figure through the flow hole 42 of the first main flow path 41A, but is blocked by the first intermediate blockage section 43d.

[0065] The refrigerant blocked by the first intermediate blockage 43d moves in the thickness direction (Z direction in the figure), as shown in Figure 8, and reaches a crossing channel 51 (connection hole 52) formed in one of the multiple second layers 50 (flow F2 in Figure 8). Then, as shown in Figure 7, the refrigerant flows through the connection hole 52 of the crossing channel 51 in the Y direction in the figure (flow F3 in Figure 7). The refrigerant then reaches a second main channel 41B formed in one of the multiple first layers 40. Specifically, the refrigerant moves to the second main channel 41B through a plurality of connection holes 52 located between the inlet end 411 and the first intermediate blockage 43d in the X direction in the figure. The refrigerant that has moved to the second main channel 41B flows through the flow holes 42 of the second main channel 41B in the X direction in the figure and is blocked by the second intermediate blockage 43e (flow F4 in Figure 7).

[0066] The refrigerant blocked by the second intermediate blockage 43e moves to the first main flow path 41A via the connection holes 52 of the crossing flow path 51, as in the case described above (flow F5 in Figure 7). Specifically, the refrigerant moves to the first main flow path 41A via a plurality of connection holes 52 located between the first intermediate blockage 43d and the second intermediate blockage 43e in the Y direction in the figure. The refrigerant that has moved to the first main flow path 41A flows in the X direction in the figure through the flow holes 42 of the first main flow path 41A and is blocked by the outlet blockage 43b (flow F6 in Figure 7).

[0067] The refrigerant blocked by the outlet blockage 43b moves to the second main flow path 41B through the connection holes 52 of the crossing flow path 51 (flow F7 in Figure 7). Specifically, the refrigerant moves to the second main flow path 41B through a plurality of connection holes 52 located between the second intermediate blockage 43e and the outlet blockage 43b in the X direction in the figure. The refrigerant that has moved to the second main flow path 41B flows through the flow holes 42 of the second main flow path 41B in the X direction in the figure and flows out from the outlet end 412 (flow F8 in Figure 7).

[0068] In the case of multiple fins 70, the refrigerant moves only in the X direction. In contrast, in the laminated structure 20 described above, the refrigerant moves not only in the X direction but also in the Y and Z directions, thus increasing the contact area with the refrigerant. Therefore, the laminated structure 20 has higher cooling performance compared to the fins 70.

[0069] As mentioned above, the reason the refrigerant flows in a meandering manner between the first main flow path 41A and the second main flow path 41B is that the second intermediate blockage section 43e is located on the outlet side of the first intermediate blockage section 43d (see Figures 5 and 7). In other words, in the X direction in the figures, the second intermediate blockage section 43e is located between the first intermediate blockage section 43d and the outlet blockage section 43b. As a result, the blockage sections 43 are alternately arranged in the first main flow path 41A and the second main flow path 41B from the inlet side to the outlet side, such as the inlet blockage section 43a of the second main flow path 41B, the first intermediate blockage section 43d of the first main flow path 41A, the second intermediate blockage section 43e of the second main flow path 41B, and the outlet blockage section 43b of the first main flow path 41A. In other words, a flow path set consisting of one first main flow path 41A and one second main flow path 41B has a plurality of blockage sections 43, and in this flow path set, the plurality of blockage sections 43 are alternately arranged in the first main flow path 41A and the second main flow path 41B when viewed in the X direction in the figure. This makes the meandering of the refrigerant as described above.

[0070] Furthermore, as shown in Figure 7, each connection hole 52 (crossing channel 51) is arranged such that it opens near each of the respective occluded sections 43 (for example, the outlet occluded section 43b). More specifically, in the first main channel 41A, a connection hole 52 (crossing channel 51) opens in a portion adjacent to the occluded section 43 (outlet occluded section 43b, first intermediate occluded section 43d) in the X direction in the figure. Also, in the second main channel 41B, a connection hole 52 (crossing channel 51) opens in a portion adjacent to the occluded section 43 (second intermediate occluded section 43e, inlet occluded section 43a) in the X direction in the figure. This suppresses the accumulation of refrigerant near the occluded sections 43.

[0071] Furthermore, the parallel flow path 41 does not necessarily need to have an intermediate blockage section 43c. In this case, the flow path forming section 31 of the second layer 50 only needs to have at least one crossing flow path 51 connecting the first main flow path 41A and the second main flow path 41B. Even with such a configuration, the refrigerant can be moved between the first main flow path 41A and the second main flow path 41B via the crossing flow path 51.

[0072] Furthermore, the outlet closure portion 43b is not provided in the first main flow path 41A, nor is the inlet closure portion 43a provided in the second main flow path 41B. Even in this case, at least some of the refrigerant moves between the first main flow path 41A and the second main flow path 41B via the crossing flow path 51.

[0073] Next, the flow of refrigerant in the cold plate 1 in this embodiment will be explained with reference to Figure 1.

[0074] Although not specifically shown in the diagram, the inlet 121 of case 10 is connected to the supply piping of a refrigerant supply device. This refrigerant supply device includes, for example, a pump and a chiller, and is capable of supplying refrigerant. As shown in Figure 1, the refrigerant supplied from this refrigerant supply device flows into the internal space 101 of case 10 through the inlet 121.

[0075] The refrigerant that flows into the internal space 101 enters the heat exchange section 21 of the laminate 20. Specifically, the refrigerant flows into the first main flow path 41A of the multiple first layers 40 provided in the laminate 20. In addition, the refrigerant flows into the lower part of the heat exchange section 21, which is covered by the cover section 22 in the laminate 20, via the distribution hole 24.

[0076] Then, as explained with reference to Figures 7 and 8, this refrigerant passes through the flow path within the laminate 20. In this process, the refrigerant absorbs heat from the high-heat-generating semiconductor device 110 via the heat exchange section 21 of the laminate 20.

[0077] The refrigerant that has passed through the flow path within the laminate 20 flows out from the second main flow path 41B of the multiple first layers 40 provided in the laminate 20. In addition, the refrigerant flows out from the lower part of the heat exchange section 21, which is covered by the cover section 22 in the laminate 20, through the confluence hole 25.

[0078] The refrigerant that flows out from the laminate 20 passes through the gaps between the multiple fins 70. In this process, the refrigerant absorbs heat from the low-heat-generating semiconductor device 120 via the fins 70.

[0079] Although not specifically shown in the diagram, the outlet 122 of case 10 is connected to the recovery piping of the refrigerant supply device described above. The refrigerant that has passed between the fins 70 flows out of the internal space 101 of case 10 via the outlet 122 and is recovered by the refrigerant supply device via the recovery piping.

[0080] As described above, in this embodiment, the laminate 20 and a plurality of fins 70 are arranged in the internal space 101 through which the refrigerant flows, thereby optimizing the cooling performance and pressure loss of the cold plate 1.

[0081] In this case, when using a cold plate equipped only with a laminate and no fins to cool a high-heat semiconductor device 110 and a low-heat semiconductor device 120, the cooling performance of the cold plate may become excessive relative to the heat source. In contrast, in this embodiment, the cooling performance of the cold plate 1 can be optimized by assigning the laminate 20, which has high cooling performance, to cooling the high-heat semiconductor device 110, and assigning the multiple fins 70, which have low cooling performance, to cooling the low-heat semiconductor device 120.

[0082] Furthermore, since laminates have a greater pressure loss compared to fins, using a cold plate equipped only with laminates and without fins may require a higher-pressure pump, potentially leading to increased costs for the refrigerant supply system. In contrast, this embodiment optimizes pressure loss by assigning the laminate 20, which has high cooling performance, to the cooling of the high-heat-generating semiconductor device 110, and assigning the multiple fins 70, which have low cooling performance, to the cooling of the low-heat-generating semiconductor device 120.

[0083] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0084] For example, as shown in Figure 9, the front end surface 221 of the cover portion 22 may be located on the same plane as the lower surface 112 of the bottom plate 11 of the case 10. Figure 9 is a cross-sectional view showing a cold plate in another embodiment of the present invention. In this case as well, the laminate 20 can efficiently cool the high-heat-generating semiconductor device 120. Alternatively, although not specifically shown, the front end of the cover portion 22 may be exposed from the bottom plate 11 through the opening 111, while the front end surface 221 of the cover portion 22 may be located inside the opening 111. Also, although not specifically shown, the front end surface 221 of the cover portion 22 may be exposed from the bottom plate 11 through the opening 111, while the front end surface 221 of the cover portion 22 may be located on the same plane as the upper surface of the bottom plate 11. In this case, the lower part 222 of the cover portion 22 is not located inside the opening 111, but closes the opening 111 from above. Furthermore, in this case, the side portion 223 of the cover portion 22 does not necessarily have to be formed, and the flange portion 23 described above may protrude from the outer circumference of the lower portion 222 of the cover portion 22.

[0085] Alternatively, as shown in Figure 10, the entire laminate 20 may be housed in the internal space 101 of the case 10 without exposing the leading edge of the laminate 20 from the case 10. Figure 10 is a cross-sectional view showing a cold plate in yet another embodiment of the present invention. In this case as well, the cooling performance and pressure loss of the cold plate 1 can be optimized.

[0086] Furthermore, in the embodiment described above, two semiconductor devices 110 and 120 with different heat generation values ​​were cooled by one cold plate 1, but three or more semiconductor devices may be cooled by one cold plate 1. In this case as well, the laminate 20 is assigned to cooling the high-heat-generating semiconductor device, and the fins 70 are assigned to cooling the low-heat-generating semiconductor device.

[0087] Furthermore, although not specifically shown in the figures, if a single semiconductor device has multiple heat-generating regions with different heat generation amounts, these multiple heat-generating regions may be cooled by a single cold plate 1. In this case, the laminate 20 or fins 70 are assigned to each heat-generating region according to the heat generation amount of each heat-generating region of the semiconductor device.

[0088] Furthermore, in the embodiment described above, the refrigerant is introduced into the laminate 20 from the side of the laminate 20, but as shown in Figures 11 and 12, the refrigerant may also be introduced into the laminate 20 from above.

[0089] Figure 11 is a cross-sectional view showing a cold plate 1 in yet another embodiment of the present invention. Figure 12 is a cross-sectional view along the line XII-XII in Figure 11. As shown in Figures 11 and 12, in this embodiment, the side portion 223 of the cover portion 22 has an extended portion 224 that extends from the lower portion 222 to the lower surface of the upper plate 13 of the lid 12. In this embodiment, a part of the flange portion 23 protrudes radially outward from the side surface of this extended portion 224 toward the laminate 20.

[0090] In this embodiment, the distribution hole 24 is a slit formed between the side portion 223 and the heat exchange portion 21. The distribution hole 24 is not particularly limited, but is defined by the lower part 222 of the cover portion 22, the side portion 223 of the cover portion 22, and the heat exchange portion 21. Therefore, unlike the above-described embodiment, the depth of the distribution hole 24 is set to be approximately the same as the height of the heat exchange portion 21.

[0091] Furthermore, depending on the design of the laminate 20, the distribution holes 24 may be formed inside the heat exchange portion 21 so as to penetrate the heat exchange portion 21 in the stacking direction, rather than between the side portion 223 of the cover portion 22 and the heat exchange portion 21. In this case, the extension portion 224 from the side portion 23 may be omitted. That is, the structure of the cover portion 22 may be the same shape as the cover portion 22 shown in Figures 1 to 3.

[0092] Furthermore, in this embodiment, the inlet 121 of the lid 12 is positioned to correspond to the distribution hole 24. Specifically, the inlet 121 is positioned above the distribution hole 24 and faces the distribution hole 24.

[0093] In the cold plate 1 of this embodiment, first, the refrigerant that has passed through the inlet 121 flows into the distribution hole 24 of the laminate 20 from above. The refrigerant that has flowed into the distribution hole 24 then flows from the distribution hole 24 into the heat exchange section 21. This refrigerant then passes through the flow path within the laminate 20 as described with reference to Figures 7 and 8. The refrigerant that has passed through the flow path within the laminate 20 flows out from the second main flow path 41B of the multiple first layers 40 provided in the laminate 20. The refrigerant also flows out from the lower part of the heat exchange section 21, which is covered by the cover section 22 in the laminate 20, through the confluence hole 25. The refrigerant that has flowed out from the laminate 20 passes through the gaps between the multiple fins 70. Finally, the refrigerant that has passed between the fins 70 flows out from the internal space 101 of the case 10 via the outlet 122 and is recovered by the refrigerant supply device via the recovery piping. In this case as well, the cooling performance and pressure loss of the cold plate 1 can be optimized.

[0094] Furthermore, in the embodiment described above, the extension direction of the fins 70 is the X direction in the figure, but the extension direction of the fins 70 may be a direction other than the X direction. In this case as well, the cooling performance and pressure loss of the cold plate 1 can be optimized.

[0095] Figure 13 is a cross-sectional view showing a cold plate 1 in yet another embodiment of the present invention. As shown in Figure 13, for example, the direction of extension of the fins 70 may be the Y direction in the figure. Furthermore, it is preferable that the cold plate 1 in this embodiment further comprises a pair of flow straightening walls 80. The pair of flow straightening walls 80 are formed to control the flow of refrigerant in the vicinity of the fins 70.

[0096] Each of the rectifying walls 80 is a plate-shaped wall that protrudes from the upper surface of the bottom plate 11 (see Figure 11) toward the internal space 101. The pair of rectifying walls 80 are arranged so as to sandwich the multiple fins 70. One rectifying wall 80 is provided between the laminate 20 and the fins 70, and the other rectifying wall 80 is provided between the fins 70 and the outlet 122. Furthermore, one rectifying wall 80 extends parallel to the fins 70 from one inner wall of the cylindrical portion 14 (the inner wall on the +Y direction side in the figure) and is separated from the other inner wall of the cylindrical portion 14 (the inner wall on the -Y direction side in the figure). The other rectifying wall 80 extends parallel to the fins 70 from the other inner wall of the cylindrical portion 14 and is separated from the inner wall of the cylindrical portion 14. By providing such rectifying walls 80, the refrigerant near the multiple fins 70 flows more easily toward the +Y direction in the figure.

[0097] Although not specifically shown, in the cold plate 1 of the embodiments shown in Figures 1 and 2, the direction of extension of the fins 70 may be a direction other than the X direction. For example, the direction of extension of the fins 70 may be the Y direction. In this case, similar to the cold plate 1 shown in Figure 13, the cold plate 1 may further include the pair of flow straightening walls 80 described above.

[0098] 1...Cold plate 10...Case 101...Internal space 11...Bottom plate 111...Opening 112...Bottom surface 12...Lid 121...Inlet 122...Outlet 13...Top plate 14...Cylindrical section 20...Laminate 21...Heat exchange section 22...Cover section 221...Front surface 222...Lower part 223...Side section 224...Extending section 23...Flange section 24...Distribution hole 25...Confluence hole 30, 30A-30C...Flow channel forming layer 31...Flow channel forming section 32...Frame section 40...First layer 41...Parallel flow channels 411...Inlet end 412...Outlet end 41A...First main flow channel 41B...Second main flow channel 42...Flow hole 43...Blocking section 43a...Inlet blocking section 43b...Outlet blocking section 43c-43e...Intermediate closure section 50...Second layer 51...Crossing channel 52...Connection hole 53...Disconnected section 60...Bottom layer 70...Fin 80...Rectifying wall 100...Substrate 110, 120...Semiconductor device

Claims

1. A cold plate comprising: an internal space through which a refrigerant flows; a laminated body having a first layer and a second layer arranged in a stack; and a plurality of fins arranged in the internal space, wherein the first layer has a first flow path through which the refrigerant flows; and the second layer has a second flow path communicating with the first flow path through which the refrigerant flows.

2. A cold plate according to claim 1, wherein the cold plate comprises a case having the internal space, and the laminate and the plurality of fins are housed within the case.

3. A cold plate according to claim 2, wherein the plurality of fins are provided on the bottom plate of the case and are integrally formed with the bottom plate.

4. A cold plate according to claim 2 or 3, wherein the case has an opening formed in the bottom plate of the case, and the laminate is a cold plate exposed from the bottom plate through the opening.

5. A cold plate according to claim 4, wherein the laminate is a cold plate protruding from the bottom plate through the opening.

6. A cold plate according to claim 4 or 5, wherein the laminate comprises a flange portion that joins with the bottom plate around the opening.

7. A cold plate according to any one of claims 1 to 6, wherein the laminate comprises a heat exchange section having a flow path including the first flow path and the second flow path, and the laminate comprises a distribution hole that penetrates the first and second layers and communicates with the heat exchange section, through which the refrigerant flows into the heat exchange section.

8. A cold plate according to any one of claims 1 to 7, wherein the laminate comprises a heat exchange section having a flow path including the first flow path and the second flow path, and the laminate has a confluence hole that penetrates the first and second layers and communicates with the heat exchange section, through which the refrigerant flows out of the heat exchange section.

9. A cold plate according to any one of claims 1 to 8, wherein the cold plate has an inlet through which the refrigerant flows into the internal space, and an outlet through which the refrigerant flows out of the internal space, and the laminate is positioned upstream of the plurality of fins in the direction of flow of the refrigerant.

10. A cold plate according to any one of claims 1 to 9, wherein the first layer has a first flow path through which the refrigerant flows in a first direction, and a third flow path through which the refrigerant flows in the first direction and which is positioned differently from the first flow path in a second direction intersecting the first direction, and the second flow path communicates with the first flow path and the third flow path and through which the refrigerant flows in the second direction.

11. A cold plate according to any one of claims 1 to 10, wherein the laminate comprises a plurality of first layers and a plurality of second layers.

12. A cold plate according to any one of claims 1 to 11, wherein the plurality of fins include a plurality of plate-shaped fins arranged parallel to each other.

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