Liquid-cooled heatsink

Abstract

This invention provides an inexpensive liquid-cooled heat sink that forms a cooling block with a microchannel structure by laminating heat transfer plates that have been press-punched. [Solution] A liquid-cooled heat sink in which a cooling block 30 is housed in a housing 1H, and a heating element Dht is positioned in close proximity to the housing 1H. The cooling block 30 has multiple slit-shaped passage holes 32 formed in parallel, penetrating in the stacking direction of multiple heat transfer plates 31 and extending from one end 32a close to the inlet 15 to the other end 32c close to the outlet 16. The housing 1H has clamping parts 14 and 24 that clamp the cooling block 30 so that the passage holes 32 are closed from both sides in the stacking direction at the central part 32b, while the multiple one end 32a and multiple other end 32c are open on both sides in the stacking direction. It also has a first manifold part 40 that connects the multiple one end 32a to the inlet 15 and a second manifold part 50 that connects the multiple other end 32c to the outlet 16.

Description

Technical Field

[0001] The present invention relates to a liquid-cooled heat sink, and particularly to a liquid-cooled (liquid-cooling type) heat sink having a microchannel structure.

Background Art

[0002] Recently, in small heat-generating bodies, such as highly integrated and high-performance electronic devices, the amount of heat generated has been constantly increasing. In the current situation where the allowable temperature itself has not changed much, it has become difficult to cope with an air-cooled heat sink (radiator). Therefore, a water-cooled heat sink with a greater cooling effect, capable of miniaturization and low noise, has been increasingly popularized.

[0003] In such a liquid-cooled heat sink, various measures have been taken to increase the heat transfer area in order to achieve miniaturization and improve the cooling performance. Among them, there is a high demand for a heat sink having a microchannel structure, which is excellent in miniaturization and high efficiency and has a further heat removal effect.

[0004] A heat sink having a microchannel structure is one in which the hydraulic equivalent diameter of the flow channel groove is microchannelized to 1 mm or less, and the number of flow channels is increased, so that the heat transfer area can be increased by dozens of times, and it is easy to increase the heat exchange amount and improve the cooling capacity.

[0005] Conventional liquid-cooled heat sinks of this type include, for example, those having a multi-layer structure in which cooling blocks thermally conducted from a heat-generating body alternately stack a flow channel plate having cooling passage holes and a heat transfer plate (see, for example, Patent Documents 1 to 3), or those in which irregularities for forming cooling passages, such as flow channel grooves, are formed on at least one heat transfer surface of each pair of adjacent heat transfer plates in the stacking direction, and a plurality of pairs of heat transfer plates are stacked to form a cooling block (see, for example, Patent Document 4).

[0006] Furthermore, another type of liquid-cooled heat sink is known in which the cooling block, which receives heat from a heat-generating element, is composed of first and second cooling substrates, and one of the substrates is provided with multiple rows of groove-shaped recesses that deepen in a stepped manner from the surface to the bottom, while the other substrate is provided with multiple rows of protrusions that are inserted into the groove-shaped recesses and form multiple cooling passages, each having a thin portion in the thickness direction and a large heat transfer area (see, for example, Patent Document 5). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2007-205694 [Patent Document 2] Japanese Patent Publication No. 2007-242724 [Patent Document 3] Japanese Patent Publication No. 2007-200834 [Patent Document 4] Special Publication No. 2009-541053 [Patent Document 5] Japanese Patent Publication No. 2011-181863 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in conventional liquid-cooled heatsinks as described above, in order to improve cooling performance by constructing a cooling block with a microchannel structure, it was necessary to alternately stack flow channel plates and heat transfer plates with different through-hole shapes to form high aspect ratio cooling passages, or to use heat transfer plates with unpenetrated grooves or holes for flow channel formation processed by etching or machining on the heat transfer surface. As a result, there was a problem that the manufacturing cost of the heatsink was high.

[0009] In other words, when using heat transfer plates and flow channel plates, while the press punching process can be made easier by increasing the size of the punched holes for forming the flow channels, it is necessary to prepare heat transfer plates and flow channel plates with the same outer shape but different punched hole shapes, and to stack them alternately to form a cooling block. This not only increases the number of parts but also complicates assembly. Furthermore, it is necessary to integrate the stacked heat transfer plates and flow channel plates in a liquid-tight (water-tight) manner by diffusion bonding or the like, which increases the manufacturing cost of the heat sink.

[0010] On the other hand, when forming grooves or holes for channel formation on heat transfer plates by etching or machining, it is necessary to stack many heat transfer plates to secure a heat transfer area, which requires mass production of heat transfer plates. However, etching and machining increase the processing cost of many heat transfer plates, resulting in high manufacturing costs.

[0011] Furthermore, in conventional liquid-cooled heat sinks, the flow direction and changes in the cross-sectional area of ​​the cooling passages are fixed due to the structure of the cooling block. Specifically, the size (cross-sectional area) of each inlet and outlet of the multiple cooling passages is fixed. This makes it difficult to adjust pressure loss or cooling performance within the cooling block, which also contributes to high manufacturing costs.

[0012] Furthermore, while it is conceivable to adjust the number of heat transfer plates stacked to fine-tune the cooling performance of the cooling block, even if this were possible, the cooling block structure does not allow for changes to the aspect ratio (ratio of the heat transfer surface height to the width of the perpendicular passage) in the cross-section of each cooling passage. Therefore, it is not possible to directly adjust the cooling performance from directly below the contact surface area between the heat source and the cooling block, and thus effective cooling performance adjustment could not be achieved.

[0013] The present invention aims to provide an inexpensive heat sink that constructs a cooling block with a microchannel structure by stacking inexpensive heat transfer plates of a single type, and also aims to provide a liquid-cooled heat sink that allows for easy adjustment of the number of stacked plates and the size of the entrances and exits of each cooling passage forming the microchannel structure, thereby allowing for easy adjustment of the pressure loss and cooling performance within the cooling block. [Means for solving the problem]

[0014] The liquid-cooled heat sink according to the present invention, in order to achieve the above objective, comprises (1) a housing formed with an inlet and outlet for a cooling fluid and a cooling chamber through which the cooling fluid passes, and a cooling block having a plurality of heat transfer plates stacked in the thickness direction and having a plurality of cooling passages formed inside, wherein the cooling block is housed in the cooling chamber of the housing, and the housing is provided with a heat conduction region in which a heat source is placed in close proximity, wherein the cooling block has a plurality of slit-shaped passage holes that penetrate in the stacking direction of the plurality of heat transfer plates and extend from one end side close to the inlet side to the other end side close to the outlet side perpendicular to the stacking direction The cooling block is formed in parallel with predetermined intervals in the direction of separation, and the housing is characterized by having a clamping portion that holds the cooling block so as to close the plurality of slit-shaped passage holes from both sides in the stacking direction of the plurality of heat plates at the central portion in the extending direction, while leaving the one end and the other end of the plurality of slit-shaped passage holes open on both sides in the stacking direction of the plurality of heat plates, respectively; a first manifold portion that connects the one end of the plurality of slit-shaped passage holes to the cooling fluid inlet; and a second manifold portion that connects the other end of the plurality of slit-shaped passage holes to the cooling fluid outlet.

[0015] In this configuration, multiple slit-shaped passage holes penetrate the stacking direction of multiple heat transfer plates, extend from one end near the inlet to the other end near the outlet, and are arranged in parallel at predetermined intervals in a direction perpendicular to the stacking direction. As a result, the height of the passage cross-section (the height of the heat transfer surface that dissipates heat to the cooling fluid) of each slit-shaped passage hole becomes the stacking height of the multiple heat transfer plates, allowing a cooling block to be constructed by stacking only one type of heat transfer plate. Therefore, the manufacturing cost of the heat sink can be reduced.

[0016] Furthermore, in the present invention, each heat transfer plate constituting each layer of the cooling block has multiple slit-shaped passage holes in each layer, which are press-punched in the thickness direction at positions where the multiple slit-shaped passage holes are formed in parallel.

[0017] Therefore, multiple slit-shaped passage holes in each layer of heat transfer plates can be formed at low cost by press punching, and when the heat transfer plates are stacked to form a cooling block, multiple slit-shaped passage holes penetrating in the stacking direction of the multiple heat transfer plates can be formed into cooling passages with a high aspect ratio corresponding to the number of stacked heat transfer plates.

[0018] (2) In a preferred embodiment of the present invention, the first manifold section has an inlet tank section that extends from the inlet side in a spaced-out direction perpendicular to the stacking direction and introduces the cooling fluid from the inlet, and a plurality of inlet side branch pipe sections on one side of the stacking direction and a plurality of inlet side branch pipe sections on the other side of the stacking direction, each connecting one end of the plurality of slit-shaped passage holes to the inlet tank on both sides of the stacking direction of the plurality of heat transfer plates, and the second manifold section has an outlet tank section that extends from the outlet side in a spaced-out direction perpendicular to the stacking direction and discharges the cooling fluid to the outlet, and a plurality of outlet side branch pipe sections on one side of the stacking direction and a plurality of outlet side branch pipe sections on the other side of the stacking direction, each connecting the other end of the plurality of slit-shaped passage holes to the outlet tank section on both sides of the stacking direction of the plurality of heat transfer plates.

[0019] With this configuration, the branch pipe portions on one side and the other side in the stacking direction at the plurality of inflow sides and outflow sides of the first and second manifold portions are respectively the passage cross-sectional areas at the portions connecting to one end side and the other end side of the plurality of slit-shaped passage holes, that is, the inlet and outlet sizes on both sides in the stacking direction at one end side and the other end side of the plurality of slit-shaped passage holes can be easily changed to such an extent that they are changed according to the inlet size required by the shape of a part of the housing surrounding the opening.

[0020] (3) In a preferred embodiment of the present invention, the housing is composed of a first housing member and a second housing member facing each other in the stacking direction of the plurality of heat transfer plates, and at least one of the first housing member and the second housing member has a concave shape that opens in the facing direction, and the first housing member and the second housing member can be configured to be liquid-tightly joined so as to form the inflow port, the outflow port, and the cooling chamber.

[0021] With this configuration, by making the housing have a shell structure having a first housing member and a second housing member, it is possible to easily optimize the clamping retention of the cooling block and the manifold shape.

[0022] (4) In a preferred embodiment of the present invention, the housing is composed of the first housing and the second housing each made of a heat conductive material, and heat can be transferred from the heating element to at least one of the first housing and the second housing.

[0023] In this case, at least one of the first housing and the second housing made of a heat conductive material (for example, a stainless steel plate, an aluminum plate, or a copper plate) can be used as a heat transfer surface, and double-sided use becomes possible.

[0024] (5) In a preferred embodiment of the present invention, the housing is configured such that the first housing is made of a heat conductive material, while the second housing is made of a heat insulating member, and heat can be transferred from the heating element to the first housing.

[0025] In this case, since the first housing is made of a heat conductive material and the second housing is made of a heat insulating member, the heat transfer surface can be clarified, and heat conduction from the heat transfer surface side to the cooling block side and heat dissipation to the cooling fluid can be effectively promoted.

Effect of the Invention

[0026] According to the present invention, it is possible to provide an inexpensive heat sink in which an inexpensive type of heat transfer plate is laminated to form a cooling block having a microchannel structure. In addition, the number of laminated sheets and the sizes of the inlets and outlets of each cooling passage forming the microchannel structure can be easily changed, and a liquid-cooled heat sink in which the pressure loss and cooling performance in the cooling block can be easily adjusted can be provided.

Brief Description of the Drawings

[0027] [Figure 1] FIG. 1(a) is a schematic front cross-sectional view of a liquid-cooled heat sink according to an embodiment of the present invention, and FIG. 1(b) is a plan cross-sectional view showing a cross-section taken along the line B1-B1 of FIG. 1(a). [Figure 2] FIG. 2(a) is a plan view of a heat transfer plate in a liquid-cooled heat sink according to an embodiment of the present invention, and FIG. 2(b) is a partially enlarged plan cross-sectional view showing a cross-section taken along the line B2-B2 of FIG. 2(a). [Figure 3] FIG. 3(a) is a plan view showing the inner surface side of the housing in the concave first housing member of a liquid-cooled heat sink according to an embodiment of the present invention, and FIG. 3(b) is a cross-sectional view taken along the line B3-B3 of FIG. 3(a). [Figure 4] FIG. 4(a) is a front cross-sectional view of a lid-shaped second housing member in a liquid-cooled heat sink according to an embodiment of the present invention, and FIG. 4(b) is a bottom view showing the inner surface side of the housing in the second housing member. [Figure 5] Figure 5(a) is a schematic front cross-sectional view of a liquid-cooled heat sink according to another embodiment of the present invention, and Figure 5(b) is a plan cross-sectional view showing the section taken along the line B6-B6 in Figure 5(a). [Modes for carrying out the invention]

[0028] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[0029] (One embodiment) Figures 1 to 4 show a liquid-cooled heat sink and a cooling device equipped therewith according to one embodiment of the present invention.

[0030] First, let me explain the structure.

[0031] As shown in Figures 1 to 4, this embodiment is one example of a liquid-cooled heat sink 1 using a cooling fluid RF. The cooling device comprises a pump P that circulates the cooling fluid RF through a liquid-cooled plate-shaped heat sink 1 and a predetermined circulation path L, and a heat exchange type liquid cooling means C such as a radiator provided in the circulation path L. The cooling fluid RF is, for example, cooling water, but other liquid coolants may also be used.

[0032] As shown in Figure 1(a), the liquid-cooled heat sink 1 comprises a housing 1H, for example, a rectangular plate shape, formed by joining a first housing member 10 and a second housing member 20, at least one of which is concave, at their peripheral walls 12 and 22. An inlet 15 and an outlet 16 for the cooling fluid RF are formed through the rectangular frame-shaped peripheral wall 12 of the concave first housing member 10. In Figures 1 to 4, the first housing member 10 is shown as a bottomed concave shape corresponding to the cooling chamber 11, and the second housing member 20 is shown as a lid shape. However, it is of course possible for both the first housing member 10 and the second housing member 20 to be concave.

[0033] A cooling chamber 11 is defined between the first housing member 10 and the second housing member 20 of the housing 1H through which the cooling fluid RF passes. The cooling fluid RF, which flows into the housing 1H from the inlet 15 via the circulation path L, is introduced into the cooling chamber 11 and flows out of the housing 1H through the outlet 16.

[0034] Furthermore, a rectangular plate-shaped cooling block 30 is housed inside the cooling chamber 11 of the housing 1H, with most of its ends 30a and 30b (part of its outer circumferential surface) located near the inlet 15 and outlet 16 being sufficiently spaced apart from the opposing inner wall surfaces of the housing 1H that form the cooling chamber 11. The opposing inner wall surfaces of the housing 1H refer here to the inner wall surface portion 12i of the peripheral wall portion 12 of the first housing member 10 and the inner wall surface portion 22i of the peripheral wall portion 22 of the second housing member 20, which face the ends 30a and 30b of the cooling block 30. The peripheral wall portion 22 is fitted into the peripheral wall portion 12 of the first housing member 10 so as to be located above the inlet 15 and outlet 16, and its inner wall surface portion 22i is located near the inner wall surface portion 12i of the peripheral wall portion 12 of the first housing member 10 (see Figures 3 and 4).

[0035] On the other hand, on both sides of the housing 1H in the thickness direction, heat conduction regions 18 and / or 28 are provided, depending on the installation position and range of the cooling block 30 in the respective flat plate surface directions (x direction and y direction in Figure 1(b)), to which the heating element Dht can be placed in close proximity. In close proximity, for example, means that the heating element Dht is attached to or pressed against the heat conduction region 18 and / or 28 in a heat conduction manner. In Figure 1(a), the heat conduction regions 18 and 28 on both sides of the housing 1H are shown only in the central portion, but the heat conduction regions 18 and / or 28 may extend over the entire area of ​​both sides of the housing 1H.

[0036] The cooling block 30 is made up of several dozen thin plates, in this case heat transfer plates 31 made of a thermally conductive metal with a plate thickness t1 of 0.1 mm or less, stacked together. Each heat transfer plate 31 has multiple parallel passage holes 32 (cooling passages) of the same length that extend in parallel in the passage length direction (x direction), which is the left-right direction in Figures 1(b) and 2, and are formed to open on both sides of the plate thickness.

[0037] Therefore, each of the multiple slit-shaped passage holes 32 penetrates the cooling block 30 in the stacking direction of the multiple heat transfer plates 31, extends in a slit shape from one end 32a, which is close to the inlet 15, to the other end 32c, which is close to the outlet 16, and has a predetermined depth corresponding to the thickness of the cooling block 30. In addition, the multiple slit-shaped passage holes 32 are arranged parallel to each other in a separation direction (y direction in the figure) perpendicular to the stacking direction, with a predetermined interval, which will be described later.

[0038] Furthermore, the first housing member 10 and the second housing member 20 of the housing 1H have clamping portions 14 and 24 that clamp the cooling block 30 from both sides in the thickness direction at the central portion 32b of a plurality of slit-shaped passage holes 32 in the plate surface area of ​​the full outer surface plate portions 13 and 23. The plurality of slit-shaped passage holes 32 have one end 32a and the other end 32c of the clamping portions 14 and 24, respectively, opening to a predetermined size in a substantially rectangular shape on both sides in the stacking direction of the plurality of heat transfer plates 31, on the inlet 15 side from one end face 14a and 24a of the clamping portions 14 and 24, and on the outlet 16 side from the other end face 14b and 24b of the clamping portions 14 and 24.

[0039] More specifically, as shown in Figures 1(a) and 1(b), the housing 1H has a first manifold section 40 that connects multiple pairs of openings at one end 32a of the multiple slit-shaped passage holes 32 to the inlet 15 for the cooling fluid RF, and a second manifold section 50 that connects multiple pairs of openings at the other end 32c of the multiple slit-shaped passage holes 32 to the outlet 16 for the cooling fluid RF.

[0040] As shown by the dashed lines of the cooling fluid RF flow in Figures 1(a) and 1(b), the first manifold section 40 has a substantially rectangular parallelepiped inlet tank section 42 that extends from the inlet 15 side in the direction of separation (y direction) of the aforementioned plurality of slit-shaped passage holes 32, thereby introducing the cooling fluid RF from the inlet 15 to the vicinity of one end 32a of the plurality of slit-shaped passage holes 32, and a plurality of inlet-side branch pipe sections 43A on one side of the stacking direction (z direction) and an inlet-side branch pipe section 43B on the other side of the stacking direction, respectively, which connect a plurality of pairs of openings at one end 32a of the plurality of slit-shaped passage holes 32 to the inlet tank section 42 on both sides of the stacking direction of the plurality of heat transfer plates 31. Here, the multiple inflow-side branch pipe portions 43A on one side in the stacking direction and the inflow-side branch pipe portions 43B on the other side in the stacking direction are composed of the nearby wall portions of the one end faces 14a and 24a of the clamping portions 14 and 24 of the housing 1H and the portion closer to the inlet 15, and one end portion 30a of the cooling block 30 in the passage length direction.

[0041] Furthermore, the second manifold section 50 has a substantially rectangular parallelepiped outlet tank section 52 that extends from the outlet 16 side in the direction of separation (y direction) of the plurality of slit-shaped passage holes 32, thereby discharging the cooling fluid RF from the plurality of slit-shaped passage holes 32 to the outlet 16, and a plurality of outlet side branch pipe sections 53A on one side of the stacking direction and outlet side branch pipe sections 53B on the other side of the stacking direction, respectively, which connect a plurality of pairs of openings at the other end 32c of the plurality of slit-shaped passage holes 32 to the outlet tank section 52 on both sides of the stacking direction of the plurality of heat transfer plates 31. Here, the plurality of outlet side branch pipe sections 53A on one side of the stacking direction and outlet side branch pipe sections 53B on the other side of the stacking direction are composed of the nearby wall portions of the other end faces 14b, 24b of the clamping portions 14, 24 of the housing 1H and the portion closer to the outlet 16 thereof, and the other end 30b in the passage length direction of the cooling block 30.

[0042] As shown in Figure 2, each heat transfer plate 31 constituting each layer of the cooling block 30 has multiple slit-shaped passage holes 32i in the thickness direction, which are press-punched in the thickness direction at positions where multiple slit-shaped passage holes 32 of the cooling block 30 are formed in parallel. In addition, each heat transfer plate 31 has a feed portion 33i between the multiple passage holes 32i of each layer that are adjacent in the aforementioned separation direction (y direction), and each of the multiple passage holes 32i has an edge portion 34i on one end 32a and the other end 32c side.

[0043] The width f2 of each feed portion 33i and the width f1 of each edge portion 34i in the heat transfer plate 31 of each layer are greater than the plate thickness t1 of the heat transfer plate 31 of each layer (here, 0.1 mm or less), preferably more than twice the plate thickness t1, but set to a value smaller than a few times. Therefore, the cooling block 30 has multiple slit-shaped passage holes 32 formed as microchannel flow paths.

[0044] More specifically, each layer of heat transfer plate 31 is made of stainless steel (SUS) plate with a plate thickness t1 of 0.1 mm as shown in Figure 2(b), and has multiple slit-shaped passage holes 32i in each layer with an outer diameter of 24 × 35 mm, having a plate width Lx and plate length Ly as shown in Figure 2(a). 2 Within the plate size, for example, 30 narrow grooves are punched out in parallel using a hydraulic precision press, with groove width ws of 0.75 mm, individual groove widths f1 and f2 of 0.4 mm, and length Ls of 23 mm. When dozens of these punched-out pieces are stacked as heat transfer plates 31 for each layer to form a cooling block 30, multiple slit-shaped passage holes 32 are formed in parallel as flow channels with a predetermined groove depth and a high aspect ratio, which would be significantly more expensive to achieve through etching or machining.

[0045] Each layer of heat transfer plate 31 can be made of a heat-conductive metal plate material such as aluminum or copper. In this case, even if the plate thickness t1 is 0.1 mm, the groove width ws is 0.4 mm, and the widths f1 and f2 are approximately 0.3 mm, precision press punching is possible, which allows for greater efficiency, including improved heat conductivity.

[0046] When a predetermined number of such heat transfer plates 31 are stacked, they are positioned on the inner side of the peripheral wall portion 12 of the first housing member 10. At that time, the multiple heat transfer plates 31 are sequentially stacked on the inner side of the peripheral wall portion 12, positioned in the x and y directions in Figures 2(a) and 2(b) by a pair of positioning recesses 12j that face each other in the aforementioned separation direction. After stacking, they are integrally clamped and held by the clamping portions 14 and 24, with the plates also positioned in the z direction. However, a predetermined number of heat transfer plates 31, either all of the stacked plates or a divided portion thereof, may be integrally joined in advance in a stacked state by diffusion bonding or partial brazing.

[0047] The first housing member 10 and the second housing member 20 of the housing 1H are joined together in a liquid-tight, or for example, airtight, manner by brazing, bolting at the four corners, or by interposing a sealing material, so as to form an inlet 15, an outlet 16, and a cooling chamber 11.

[0048] In this way, in the liquid-cooled heat sink 1, the heat conduction region 18 or / and 28 of the housing 1H in close proximity to the heat-generating element Dht, and the cooling region 33b (a stacked region of multiple feeder portions 33i) of the cooling block 30, in which multiple slit-shaped passage holes 32 are formed in parallel at a predetermined interval f2 in the aforementioned separation direction, are arranged facing each other from the inside out, with adjacent clamping portions 14 or / and 24 in between.

[0049] Furthermore, the housing 1H is configured such that the first housing member 10 and the second housing member 20 are each made of a heat conductive material, such as the aforementioned stainless steel plate, or an aluminum plate or copper plate, and when heat from the heating element Dht is transferred to at least one of the first housing member 10 and the second housing member 20, in this case exclusively by heat conduction, that heat is conducted to the cooling block 30 via the heat conduction regions 18 and / or 28 of the housing 1H.

[0050] On the other hand, while heat from the heat-generating element Dht is conducted to the cooling block 30, when a cooling fluid RF, in this case for example cooling water, is passed through the cooling chamber 11 in the housing 1H, the heat from the cooling block 30 is transferred to the cooling fluid RF passing through the multiple slit-shaped passage holes 32 in the cooling block 30, with the opposing inner walls of the multiple slit-shaped passage holes 32 and the inner walls at both ends acting as heat transfer surfaces, and thus released (heat removal, heat dissipation).

[0051] Furthermore, the clamping portions 14 and / or 24 of the housing 1H, and the first manifold portion 40 and the second manifold portion 50 are integrally formed with each other, forming a flat plate shape as a whole. Therefore, the heat conduction regions 18 and / or 28 that contribute to heat conduction from the heat generating element Dht to the cooling block 30 and the clamping portions 14 and / or 24 have a constant thickness in their main parts, and the first manifold portion 40 and the second manifold portion 50 also have a substantially uniform thickness (height) at each position in the plate surface direction (x direction and y direction) of the housing 1H.

[0052] Next, I will explain the mechanism of action.

[0053] In the liquid-cooled heat sink 1 of this embodiment having the configuration described above, a plurality of slit-shaped passage holes 32 penetrate the stacking direction of the plurality of heat transfer plates 31, extend from one end 32a near the inlet 15 to the other end 32c near the outlet 16, and are arranged in parallel with a predetermined interval f2 in a direction perpendicular to the stacking direction. Therefore, each slit-shaped passage hole 32 has a passage cross-section (heat transfer surface that releases heat to the cooling fluid RF) with a height h corresponding to the thickness of the cooling block 30 (stacking height of the plurality of heat transfer plates 31), and the cooling block 30 can be constructed by stacking a plurality of heat transfer plates 31 of one type that have been press-punched.

[0054] As a result, the manufacturing cost of the liquid-cooled heat sink 1 can be significantly reduced compared to conventional microchannel heat sinks, which require alternating stacking of multiple types of heat transfer plates, etching, and machining.

[0055] Furthermore, in this embodiment, multiple slit-shaped passage holes 32i in each layer of the heat transfer plate 31 are formed at low cost by press punching, and when the heat transfer plates 31 are stacked to form a cooling block 30, multiple slit-shaped passage holes 32 penetrating in the stacking direction of the multiple heat transfer plates 31 can be formed into high aspect ratio cooling passages with an aspect ratio (passage height h: passage width ws) corresponding to the number of stacked heat transfer plates 31. Therefore, cooling performance can be improved.

[0056] Furthermore, in this embodiment, the multiple branch pipe portions 43A and 43B on one and the other side in the stacking direction of the first manifold portion 40 and the multiple branch pipe portions 53A and 53B on one and the other side in the stacking direction of the second manifold portion 50 respectively have passage step areas of multiple pairs of openings on both sides in the stacking direction at one end 32a and the other end 32c of the multiple slit-shaped passage holes 32, that is, the inlets and outlets on both sides in the stacking direction at one end 32a and the other end 32c of the multiple slit-shaped passage holes 32. The opening size of the opening can be easily changed by modifying or setting multiple shapes of the clamping portions 14, 24 of the housing 1H surrounding the opening and the ends 30a, 30b on both sides in the passage length direction of the cooling block 30, according to the required entrance size. For example, by adding (partially machining) the positions of the end faces 14a, 14b on both sides of the clamping portion 14 and the end faces 24a, 24b on both sides of the clamping portion 24, or by preparing multiple types of housings 1H with different sizes of clamping portions 14, 24.

[0057] In addition, by making the housing 1H a shell structure having a first housing member 10 and a second housing member 20, the clamping hold of the cooling block 30 and the first manifold section 40 and the second manifold section 50 can be easily manufactured with an optimal branch passage opening size by utilizing both ends 30a and 30b in the passage length direction of the cooling block 30.

[0058] Furthermore, since the feed width f2 between the multiple slit-shaped passage holes 32i in each layer of the heat transfer plate 31 is more than twice the plate thickness t1, the press punching of the heat transfer plates 31 constituting each layer of the cooling block 30 can be performed quickly, accurately, and with the required processing precision.

[0059] Furthermore, since the cooling region 33b of the cooling block 30 is positioned as a stacked region of multiple feeder portions 33i on the inward side in the stacking direction, directly below the heat conduction region 18 or 28 of the first housing member 10 and / or the second housing member 20 to which heat is transferred from the heat-generating element Dht, effective heat conduction and heat dissipation to the cooling fluid RF in the cooling region 33b can be effectively generated.

[0060] In this embodiment, the cooling block 30 can be easily constructed by simply stacking multiple heat transfer plates 31 between the first housing member 10 and the second housing member 20, in contact with the clamping portions 14 and 24. Furthermore, at least one of the flat first housing member 10 and the second housing member 20, which are made of a heat conductive material, can be effectively used as a heat transfer surface, making it possible to use both sides.

[0061] Furthermore, by configuring the first housing member 10 and the second housing member 20 so that one is made of a thermal conductive material and the other is made of an insulating material, the heat transfer surface in close proximity to the heat-generating element Dht can be clearly defined, and heat conduction from that heat transfer surface side to the cooling block 30 side and heat dissipation to the cooling fluid RF can be effectively promoted.

[0062] Thus, this embodiment offers the advantage of providing a cooling device with a low manufacturing cost that includes a low-cost heatsink 1.

[0063] Furthermore, the other effects can be summarized as follows: (1) Potential for miniaturization and weight reduction: In addition to microchannelization, the use of aluminum for the heat transfer plate 31 will enable significant improvements in performance, weight reduction, and miniaturization. (2) Ease of specification changes: By increasing or decreasing the number of stacked plates according to the required specifications, flow rate adjustment and pressure loss countermeasures can be made inexpensively and freely. (3) Lower cost: In addition to adopting a cooling block 30 made by press-forming multiple heat transfer plates 31, bolt tightening, crimping, and fitting can be easily used when assembling it with the first and second housings 10 and 20, making it possible to manufacture it at a low cost and allowing for disassembly and cleaning, resulting in a heat sink with better cost performance. (4) Wide range of applicability: By combining multiple cooling blocks 30, each consisting of multiple stacked heat transfer plates 31, the cooling block can be applied to objects that generate even more heat. (5) Double-sided / single-sided cooling: Both sides of the plate-shaped heat sink 1 can be used. Of course, by changing the first housing member 10 or the second housing member 20 on one side to an insulating material, it can also be used as a single-sided cooling type.

[0064] (Other embodiments) Figures 5(a) and 5(b) show a liquid-cooled heat sink and a cooling device equipped therewith according to another embodiment of the present invention.

[0065] As shown in Figures 5(a) and 5(b), this embodiment is a cooling device comprising a cooling fluid RF, a liquid-cooled plate-shaped heat sink 2, a pump P that circulates the fluid through a predetermined circulation path L2, and a heat exchange type liquid cooling means C such as a radiator provided in the circulation path L2.

[0066] As shown in Figure 5(a), the liquid-cooled heat sink 2 comprises a housing 2H, for example, a rectangular plate-shaped housing, formed by joining a first housing member 60 and a second housing 70, at least one of which is concave, at the upper end of the peripheral wall portion 62 of the first housing member 60. An inlet 65 and outlets 66, 67 for the cooling fluid RF are formed through the rectangular frame-shaped peripheral wall portion 62 of the concave first housing member 60.

[0067] A cooling chamber 61 is defined between the first housing member 60 and the second housing 70 of the housing 2H through which the cooling fluid RF passes. The cooling fluid RF flows into the housing 2H from the central inlet 65 in the length direction of the passage (x direction) and is introduced into the cooling chamber 61, and flows out of the housing 2H through outlets 66 and 67 on both sides in the length direction of the passage.

[0068] Furthermore, inside the cooling chamber 61 of the housing 2H, a plurality of, for example, four rectangular plate-shaped cooling blocks 30A, 30B, 30C, and 30D, each configured similarly to the cooling block 30 in one embodiment, are housed, spaced apart from each other between their end faces on the central side in the passage length direction (x direction) near the inlet 65, and sufficiently spaced apart from the opposing inner wall surfaces of the housing 2H that form the cooling chamber 61, on the end faces near the outlets 66 and 67. In this case, the opposing inner wall surfaces of the housing 2H refer to a pair of inner wall surface portions 62i of the peripheral wall portion 62 of the first housing member 60 that face both outer end faces of the cooling blocks 30A to 30D.

[0069] Furthermore, the first housing member 60 and the second housing 70 of the housing 2H are provided with a pair of lower clamping portions 64 and a pair of upper clamping portions 74, respectively, which are spaced apart by a predetermined distance in the passage length direction, with the central inlet 65 in between. These pairs of 64 and 74 are also spaced apart by a predetermined distance from the outlets 66 and 67 on both sides in the passage length direction.

[0070] On the other hand, on both sides of the housing 2H in the thickness direction, heat conduction regions 68 and / or 78 are provided where the heat-generating element Dht can be placed in close proximity, depending on the installation position and range of the cooling blocks 30A to 30D in the respective flat plate surface directions (x direction and y direction in Figure 5(b)).

[0071] Furthermore, the housing 2H has a first manifold section 80 that connects multiple pairs of openings at one end 32a of multiple slit-shaped passage holes 32 in each of the cooling blocks 30A and 30C, and multiple pairs of openings at the other end 32c of multiple slit-shaped passage holes 32 in each of the cooling blocks 30B and 30D (hereinafter, both sets of multiple openings are collectively referred to as the inner end openings) to the inlet 65 of the cooling fluid RF. In addition, the housing 2H has a pair of left and right second manifold sections 90 that connect multiple pairs of openings at the other end 32c of multiple slit-shaped passage holes 32 in each of the cooling blocks 30A and 30C, and multiple pairs of openings at one end 32a of multiple slit-shaped passage holes 32 in each of the cooling blocks 30B and 30D (hereinafter, both sets of multiple openings are collectively referred to as the outer end openings) to the outlets 66 and 67 of the cooling fluid RF.

[0072] The first manifold section 80 has a substantially rectangular parallelepiped inlet tank section 82 that extends from the inlet 65 side in the direction of separation (y direction) of the aforementioned plurality of slit-shaped passage holes 32, as shown by the dashed line of the flow of the cooling fluid RF in Figure 5(a), thereby introducing the cooling fluid RF from the inlet 65 to the openings at the inner ends of the plurality of slit-shaped passage holes 32, and a plurality of inlet-side branch pipe sections 83A on one side of the stacking direction (z direction) and an inlet-side branch pipe section 83B on the other side of the stacking direction, respectively, which connect the openings at the inner ends of the plurality of slit-shaped passage holes 32 to the inlet tank section 82 on both sides of the stacking direction of the plurality of heat transfer plates 31. Here, the plurality of inlet-side branch pipe sections 83A on one side of the stacking direction and an inlet-side branch pipe section 83B on the other side of the stacking direction are composed of the vicinity of the opposing inner end faces of each pair of clamping sections 64, 74 of the housing 2H and the portion closer to the inlet 65 thereof, and the inner ends of the cooling blocks 30A to 30D.

[0073] Furthermore, the pair of left and right second manifold sections 90 each have a pair of substantially rectangular parallelepiped-shaped outlet tank sections 92 that extend from the outlet 66, 67 side in the direction of separation (y direction) of the plurality of slit-shaped passage holes 32, thereby discharging the cooling fluid RF from the plurality of slit-shaped passage holes 32 to the outlet 66, 67, and a plurality of outlet-side branch pipe sections 93A on one side of the stacking direction and an outlet-side branch pipe section 93B on the other side of the stacking direction, respectively, which connect the openings of the inner ends of the plurality of slit-shaped passage holes 32 to the outlet tank section 92 on both sides of the stacking direction of the plurality of heat transfer plates 31. Here, the plurality of outlet-side branch pipe sections 93A on one side of the stacking direction and an outlet-side branch pipe section 93B on the other side of the stacking direction are composed of the vicinity of the other outer end faces of the clamping sections 64, 74 of the housing 2H and the part further towards the outlet 66, 67, and the outer ends of the cooling blocks 30A to 30D in the passage length direction.

[0074] The first housing member 60 and the second housing member 70 of the housing 2H are joined together in a liquid-tight, or for example, airtight, manner by brazing, bolting at the four corners, or by interposing a sealing material, so as to form an inlet 65 and an outlet 66, 67 and a cooling chamber 61.

[0075] Furthermore, the heat conduction regions 68 and / or 78 of the housing 2H in close proximity to the heat-generating element Dht, and the multiple or entire cooling regions (the stacked regions of the multiple feeder portions 33i of each cooling block 30) of the cooling blocks 30A to 30D, in which multiple slit-shaped passage holes 32 are formed in parallel at predetermined intervals f2 in the aforementioned separation direction, are arranged facing each other from the inside out, with the adjacent clamping portions 64 and / or 74 in between.

[0076] In this embodiment, the multiple heat transfer plates 31 have, for example, a plate thickness t1 of 0.1 mm or less, an inner width ws of the slit-shaped passage holes 32i in each layer that is several times or less the plate thickness t1 and greater than the plate thickness t1, a feed width f2 between adjacent passage holes 32i in each layer that is twice or more the plate thickness t1, and a length Ls of the passage holes 32i in each layer and the slit-shaped passage holes 32 after lamination that is 10 times or more, preferably several tens of times, the inner width ws of the passage holes 32.

[0077] To give a more specific example, each layer of heat transfer plate 31 is made of aluminum or copper plate, with a plate thickness t1 of 0.1 mm, and within each layer of heat transfer plate 31, which has an outer diameter of 24 mm x 35 mm, there are 30 slit-shaped passage holes 32i for each layer, which are formed as multiple parallel narrow grooves, for example, with a groove width ws of 0.4 mm, each groove width f1, f2 of 0.3 mm, and a length Ls of 23 mm.

[0078] In this embodiment as well, each of the multiple cooling blocks 30A to 30D has multiple slit-shaped passage holes 32 that penetrate in the stacking direction of the multiple heat transfer plates 31, extend from the inner end side near the inlet 65 to the outer end side near the outlet 66, and are arranged in parallel with a predetermined interval f2 in a direction perpendicular to the stacking direction. Therefore, the height of the cross-section of each slit-shaped passage hole 32 (the height of the heat transfer surface that releases heat to the cooling fluid RF) corresponds to the stacking height h of the multiple heat transfer plates 31, which is equivalent to the thickness of each of the cooling blocks 30A to 30D, and each of the cooling blocks 30A to 30D can be constructed by stacking one type of heat transfer plate 31.

[0079] As a result, similar to the case of one embodiment, the manufacturing cost of the liquid-cooled heat sink 2 can be reduced compared to conventional microchannel structure heat sinks that require alternating stacking of multiple types of heat transfer plates or etching and machining.

[0080] Furthermore, depending on the number of cooling blocks 30A to 30D, it becomes possible to manufacture a liquid-cooled heatsink 2 with a larger cooling area.

[0081] In this embodiment, the distance between the pair of cooling blocks 30A and 30B adjacent to each other on the left and right in Figure 5(b), and the distance between the pair of cooling blocks 30B and 30D are set to be small. However, it is of course possible to adjust the distance between them, as well as the opening area of ​​the openings at the inner ends of the multiple slit-shaped passage holes 32.

[0082] Furthermore, in each of the embodiments described above, the cooling block 30 is a laminate of only one type of heat transfer plate 31. However, when changing the number of laminates from the standard specification for different required specifications, for example, a heat-conductive metal plate can be provided between the cooling block 30 and the clamping portion 14 and / or 24 of one embodiment, and the shape of the tip of the multiple branch passage portions of the first and second manifold portions 40 and 50 can be adjusted using the metal plate. Alternatively, the first housing member 10 can be made of multiple types with different heights of the peripheral wall portion 12, or the height of the peripheral wall portion 12 can be adjusted by secondary processing. Such partial machining is not applicable to a large number of heat transfer plates 31, and is particularly applicable when the first housing member 10 is molded and partial machining is required.

[0083] Furthermore, it goes without saying that the outer shape and hole shape of each layer of heat transfer plate 31 are not limited to the illustrated example. The groove width ws and feed width f2 of the multiple slit-shaped passage holes 32 may differ between the center and both ends in the separation direction (y direction), and the feed width f2 and the edge width f1 may also differ.

[0084] As described above, the liquid-cooled heat sink of the present invention can provide an inexpensive heat sink that constructs a cooling block with a microchannel structure by stacking inexpensive heat transfer plates of one type. Furthermore, it can provide a liquid-cooled heat sink in which the number of stacked heat transfer plates in each cooling block and the size of the entrances and exits of each cooling passage forming the microchannel structure can be easily changed, and the pressure loss and cooling performance within the cooling block can be easily adjusted. The present invention is useful for liquid-cooled heat sinks having a microchannel structure and cooling devices equipped therewith in general. [Explanation of symbols]

[0085] 1;2 Heatsink 1H; 2H Housing 10 First housing member 11 Cooling room 12,22 Peripheral wall part 12i,22i Inner wall part 12j recess 13,23 Full plate part 14,24 Clamping part 14a, 24a One side end surface 14b, 24b Other side end surface 15 Inlet 16 Outlet 18,28 Heat conduction region 20 Second housing member 30; 30A, 30B, 30C, 30D Cooling Block 30a One end 30b Other end 31 Heat transfer plate 32 Passage holes (multiple passage holes in the cooling block, cooling passages) 32a One end (openings on both sides in the thickness direction) 32b Central portion (closed portions on both sides in the thickness direction) 32c Other end (openings on both sides in the thickness direction) 32i Passageway holes (passageway holes on each level) 33b Cooling area (Laminated structure of the feeder section) 33i Sending part 34i En-san's part 40. First Manifold Section 42 Inflow tank section 43A, 43B Inlet side branch pipe section (branch pipe sections on both sides in the thickness direction) 50 Second Manifold Section 52 Outlet tank section 53A, 53B Outlet side branch pipe section (branch pipe sections on both sides in the thickness direction) 60 First housing member 61 Cooling room 62 Peripheral wall part 62i inner wall part 64,74 Clamping part 65 Inlet 66,67 Outlet 68,78 Heat conduction region 70 Second housing member 80 First Manifold Section 82 Inflow tank section 83A, 83B Inlet side branch pipe section (branch pipe sections on both sides in the thickness direction) 90 Second Manifold Section 92 Outlet tank section 93A, 93B Outlet side branch pipe section (branch pipe sections on both sides in the thickness direction) f1 Edge width f2 Feeder width (predetermined interval) h Height (stack height, cooling block thickness) L,L2 circulation path RF cooling fluid (cooling water) t1 plate thickness ws groove width x-direction (path length direction) y (separation direction) z-direction (stack direction, cooling block thickness direction)

Claims

1. A housing (1H) having an inlet (15) and an outlet (16) for a cooling fluid (RF) and a cooling chamber (11) through which the cooling fluid passes, The cooling block (30) comprises a plurality of heat transfer plates (31) stacked in the thickness direction and having a plurality of cooling passages (32) formed inside, A liquid-cooled heat sink is provided in which the cooling block is housed in the cooling chamber of the housing, and a heat conduction region (18 or / and 28) is provided in the housing in close proximity to a heat-generating element (Dht), The cooling block has a plurality of slit-shaped passage holes (32) that penetrate the stacking direction of the plurality of heat transfer plates and extend from one end (32a) near the inlet to the other end (32c) near the outlet, arranged in parallel at predetermined intervals (f2) in a direction perpendicular to the stacking direction. The aforementioned housing is The clamping portions (14, 24) that hold the cooling block close the plurality of slit-shaped passage holes from both sides in the stacking direction of the plurality of heat transfer plates at the central portion (32b) in the extending direction, while leaving the one end and the other end of the plurality of slit-shaped passage holes open on both sides in the stacking direction of the plurality of heat transfer plates, respectively. A first manifold section (40) connects one end of the plurality of slit-shaped passage holes to the cooling fluid inlet, It has a second manifold section (50) that connects the other end of the plurality of slit-shaped passage holes to the outlet of the cooling fluid, A liquid-cooled heat sink characterized in that each heat transfer plate (31) constituting each layer of the cooling block has a plurality of slit-shaped passage holes (32i) in each layer that are press-punched in the thickness direction at positions where the plurality of slit-shaped passage holes are formed in parallel.

2. The first manifold section includes an inlet tank portion (42) that extends from the inlet side in a spaced-out direction perpendicular to the stacking direction and introduces the cooling fluid from the inlet, and a plurality of inlet side branch pipe portions (43A) on one side of the stacking direction and an inlet side branch pipe portion (43B) on the other side of the stacking direction, each of which connects one end of the plurality of slit-shaped passage holes to the inlet tank on both sides of the stacking direction of the plurality of heat transfer plates. The liquid-cooled heat sink according to claim 1, characterized in that the second manifold portion includes an outlet tank portion (52) that extends from the outlet side in a spaced-out direction perpendicular to the stacking direction and discharges the cooling fluid to the outlet, and a plurality of outlet side branch pipe portions (53A) on one side of the stacking direction and an outlet side branch pipe portion (53B) on the other side of the stacking direction, each of which the other ends of the plurality of slit-shaped passage holes communicate with the outlet tank portion on both sides of the stacking direction of the plurality of heat transfer plates.

3. The housing is composed of a first housing member (10) and a second housing member (20) facing each other in the stacking direction of the plurality of heat transfer plates, and at least one of the first housing member and the second housing member has a concave shape that opens in the opposing direction. The liquid-cooled heat sink according to claim 1 or 2, characterized in that the first housing member and the second housing member are liquid-tightly joined to form the inlet and outlet and the cooling chamber.

4. The liquid-cooled heat sink according to claim 3, characterized in that the housing comprises a first housing and a second housing, each made of a thermal conductive material, and heat is transferred from the heating element to at least one of the first housing and the second housing.

5. The liquid-cooled heat sink according to claim 3, characterized in that the housing consists of a first housing made of a thermal conductive material and a second housing made of an insulating material, and heat is transferred from the heating element to the first housing.

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