Heatsink Structure

Abstract

To provide a heat sink structure capable of improving cooling performance while suppressing pressure loss of a cooling fluid even when a flow passage area is limited.SOLUTION: A heat sink structure 1 includes metal corrugated fins 2 each having a corrugated cross-sectional shape and having a plurality of through holes 21 opening in a plate surface 20 thereof, heat absorbing portions 3 and 4 that absorb heat from an object to be cooled and transmit the heat to the corrugated fins 2, and fluid channels 5 that supply a cooling fluid toward the plate surfaces 20 of the corrugated fins 2 to causes the fluid to flow along the through holes 21, and the heat transferred from the heat absorbing portions 3 and 4 to the corrugated fins 2 is dissipated into the fluid passing through the through holes 21.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat sink structure that is suitable for cooling a heat generating body that is an electronic circuit device that generates a large amount of heat, such as a CPU (Central Processing Unit) of a computer or a chipset. [Background technology]

[0002] Conventionally, a heat sink structure of this type has been proposed which includes a base on which a heat generating element is placed, and a number of plate-shaped fins supported on the base and parallel to each other at intervals, with each fin having a number of through holes extending in the thickness direction (arrangement direction), and in which a cooling fluid is caused to flow in the arrangement direction of the plate-shaped fins so that heat is dissipated into the cooling fluid as it passes sequentially through the through holes of each fin (see, for example, Patent Documents 1 and 2).

[0003] In this way, a heat sink structure configured to pass a cooling fluid such as air through plate-like fins having many through holes can obtain a heat transfer performance according to the contact area between the cooling fluid and the through holes. That is, in the above-mentioned heat sink structure, the smaller the diameter of the through holes and the greater the number, the better the cooling performance tends to be.

[0004] However, when the diameter of the through-hole is small, the flow resistance of the cooling fluid passing through the through-hole becomes large, and it is inevitable that the pressure loss becomes large. When the pressure loss becomes large, for example, a weak fan with a low noise level will not be able to provide a sufficient flow rate of the fluid. In order to ensure the required flow rate, it is possible to use a powerful fan, but this will increase the power consumption and noise required to drive the fan, and will also increase the equipment cost.

[0005] In addition, in order to increase the contact area between the cooling fluid and the through-holes without excessively reducing the diameter of the through-holes formed in the plate-like fins, it is possible to increase the width dimension (installation height) of the plate-like fins installed on the base of the heat sink structure. However, this would result in a problem that the heat sink would not be able to be installed in a narrow space, limiting the range of application. In addition, it would be difficult to transfer heat from the heat generating element to the tip of the plate-like fins, making it impossible to sufficiently improve the cooling performance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-358270 A [Patent Document 2] JP 2005-228948 A Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above-mentioned situation, the present invention aims to solve the problem of providing a heat sink structure that can improve cooling performance while suppressing pressure loss of the cooling fluid, even when the flow path area is limited. [Means for solving the problem]

[0008] That is, the present invention includes the following inventions.

[0009] (1) A heat sink structure comprising a metallic corrugated fin having a corrugated cross-sectional shape and a plurality of through holes opening onto its plate surface, a heat absorption section that absorbs heat from an object to be cooled and transfers the heat to the corrugated fin, and a fluid flow path that supplies a cooling fluid toward the plate surface of the corrugated fin and causes the fluid to flow along the through holes, wherein the heat transferred from the heat absorption section to the corrugated fin is dissipated into the fluid passing through the through holes.

[0010] (2) The heat sink structure according to (1), wherein the corrugated fan has a cross-sectional shape consisting of a continuous body of semicircular peaks and semicircular valleys.

[0011] (3) A heat sink structure as described in (1) or (2), wherein the heat absorption portion is a heat pipe, the peak portion and the valley portion have a radius of curvature corresponding to the heat pipe, and the heat pipe is joined along the inner surface of at least one of the peak portion or the valley portion.

[0012] (4) The heat sink structure according to any one of (1) to (3), wherein the through holes extend in a thickness direction of the corrugated plate-like fan.

[0013] (5) A heat sink structure described in any one of (1) to (4), in which a plurality of the corrugated fins are arranged at intervals with their plate surfaces facing each other, and the fluid is supplied sequentially toward the plate surfaces of each of the corrugated fins.

[0014] (6) A heat sink structure described in any one of (1) to (5), wherein the corrugated fin is a bent piece of a lotus-type porous metal molding having a plurality of pores extending in one direction and formed by a metal solidification method. Effect of the Invention

[0015] According to the heat sink structure of the present invention, the cross-sectional shape of the corrugated fins having the through holes for heat dissipation is formed in a corrugated shape, so that the total perimeter of the corrugated fin per the same cross-sectional area of ​​the flow path is longer than that of a flat fin, and the contact area between the cooling fluid and the corrugated fin is larger than that of a flat fin. In this way, the number of through holes increases in accordance with the increase in the contact area between the cooling fluid and the corrugated fin, so that a high cooling effect can be obtained, and at the same time, the flow speed of the fluid passing through each through hole can be suppressed, and the pressure loss of the fluid can be suppressed. Therefore, the cooling performance of the heat sink can be sufficiently improved without providing a powerful fan in the fluid flow path, and the problems of increased power consumption and noise generation can be avoided.

[0016] In addition, when the corrugated fin consists of a continuum of a mountain-shaped portion having a semicircular cross-sectional shape and a valley-shaped portion having a semicircular cross-sectional shape, the contact area between the cooling fluid and the corrugated fin can be increased by approximately 57% compared to flat fins, which has the advantage of providing better heat exchange capacity with a simple configuration.

[0017] In addition, when the heat absorption portion is a heat pipe, the peak-shaped portion and the valley-shaped portion have a radius of curvature corresponding to the heat pipe, and the heat pipe is joined along the inner surface of at least one of the peak-shaped portion or the valley-shaped portion, the heat pipe and the corrugated fin can be joined well, and the heat transfer area from the heat pipe to the corrugated fin can be effectively increased.

[0018] Furthermore, when the through holes are formed to extend in the thickness direction of the corrugated fin, the flow resistance of the cooling fluid passing through the through holes is reduced, thereby suppressing pressure loss and enabling efficient heat dissipation, thereby further improving the cooling performance of the heat sink.

[0019] Furthermore, in a configuration in which a plurality of corrugated fins are arranged with the plate surfaces facing each other at intervals and the fluid is supplied sequentially toward the plate surfaces of the corrugated fins, the cooling performance of the heat sink can be sufficiently ensured without taking measures such as increasing the installation height of the corrugated fins, etc. Therefore, the heat sink can be installed even in a narrow space, and can be made thinner and more compact than conventional heat sink structures.

[0020] Furthermore, when the corrugated fin is made of a cut piece of a lotus-type porous metal molding having a plurality of pores extending in one direction formed by a metal solidification method and bent, the corrugated fin can be easily manufactured at a lower cost than when each through-hole of the corrugated fin is machined by drilling, etc. Furthermore, the use of lotus metal doubles the contact area with the cooling fluid, which has the advantage of providing a high heat exchange capacity and a low-noise heat sink while suppressing pressure loss in the cooling fluid. [Brief description of the drawings]

[0021] [Figure 1] 1 is a perspective view showing a main part of a heat sink structure according to a first embodiment of the present invention; [Diagram 2] FIG. 2(a) is a front view showing a main portion of a plate-shaped material that forms a corrugated fin, and FIG. [Diagram 3] FIG. 4 is a partial cross-sectional view showing a flow state of a cooling fluid. [Figure 4] 1 is a perspective view showing a main part of a heat sink structure according to a second embodiment of the present invention. [Diagram 5] FIG. 11 is a plan cross-sectional view showing a modified example of the heat sink structure according to the second embodiment. [Figure 6] FIG. 11 is a plan cross-sectional view showing another modified example of the heat sink structure according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] First embodiment A heat sink structure according to a first embodiment of the present invention will be described with reference to Figures 1 to 3. The heat sink structure 1 according to the first embodiment of the present invention includes corrugated fins 2 made of a metal material such as aluminum, iron, or copper, which are formed in a corrugated cross section and have a plurality of through holes 21 opening on a plate surface 20 thereof, a pair of upper and lower heat absorbing parts 3 and 4 which absorb heat from an object to be cooled and transfer the heat to the corrugated fins 2, and a fluid flow path 5 which supplies a cooling fluid toward the plate surface 20 of the corrugated fins 2 and causes the fluid to flow along the through holes 21.

[0023] The heat absorbing parts 3 and 4 are formed in a rectangular plate shape using a metal material such as aluminum, iron, or copper. An object to be cooled (not shown), such as a CPU on a computer board, is placed on the upper surface of the heat absorbing part 3 in a state of close contact, and heat from the object to be cooled is transferred to the heat absorbing part 3 and absorbed. In this case, it is preferable to appropriately interpose a known grease having excellent thermal conductivity (so-called CPU grease) between the heat absorbing part 3 and the object to be cooled. The shape of the heat absorbing parts 3 and 4 is not limited to a rectangular plate shape, and one of the heat absorbing parts 3 and 4 may be omitted. In addition, the heat absorbing parts 3 and 4 may be flat heat dissipation fins of a conventional heat sink, and a corrugated fin 2 may be provided between the heat dissipation fins. The object to be cooled in the present invention is not limited to a CPU, and may be a chip set, which is an electronic circuit device that generates a large amount of heat, or other heat generating bodies.

[0024] Between the heat absorption sections 3, 4, a plurality of corrugated fins 2 are arranged in parallel at a fixed interval with the plate surfaces facing each other, and both upper and lower ends of each corrugated fin 2 are integrally joined to the heat absorption sections 3, 4 by brazing or the like. A fluid such as air blown between the heat absorption sections 3, 4 by a not shown blower fan or the like provided in the fluid flow path 5 is sequentially supplied toward the plate surfaces 20 of each of the corrugated fins 2. As a result, the cooling fluid flows along the through holes 21 of each of the corrugated fins 2, and the heat transferred to the corrugated fins 2 is dissipated into the fluid.

[0025] The corrugated fin 2 is formed using a plate-shaped material 2a (see FIG. 2) obtained by cutting a lotus-type porous metal body having a large number of pores extending in one direction formed by a metal solidification method in a direction intersecting the direction in which the pores extend. The lotus-type porous metal body is formed by a known method such as a pressurized gas method (for example, the method disclosed in Japanese Patent No. 4235813) or a thermal decomposition method.

[0026] As described above, the plate-shaped material 2a cut out from the lotus-type porous metal molding has through holes made of the pores, i.e., a plurality of through holes 21 that open on the plate surface of the plate-shaped material 2a and extend in the plate thickness direction of the plate-shaped material 2a, as shown in Fig. 2. In addition, a skin region 23 without pores is formed on the periphery of the plate-shaped material 2a by the inner wall of the mold used for molding.

[0027] Then, by pressing the plate-shaped material 2a, a metallic corrugated plate-like fin 2 is formed, which is made up of a continuum of semicircular mountain-shaped portions 24 and semicircular valley-shaped portions 25 and has a plurality of through holes 21... opening on its plate surface 20. By disposing this corrugated plate-like fin 2 between the heat absorption portions 3, 4 and supplying fluid from the fluid flow path 5 toward the plate surface 20 of the corrugated plate-like fin 2, it is possible to improve the cooling performance of the heat sink while suppressing pressure loss of the cooling fluid, even when the cross-sectional area of ​​the fluid flow path 5 is limited.

[0028] That is, when a corrugated fin 2 consisting of a continuum of semicircular mountain portions 24 and semicircular valley portions 25 is used, as shown in Fig. 3, if the diameters of the mountain portions 24 and valley portions 25 are D, then the perimeter S is πD / 2 (=1.57D), respectively. Therefore, the total perimeter of the corrugated fin 2 per the same flow passage cross-sectional area, that is, the perimeter from one end to the other end of the flow passage cross-section, is about 57% longer than that of a flat fin, and accordingly the contact area between the corrugated fin 2 and the cooling fluid is enlarged. In the illustrated example, the portions of the corrugated fin 2 that protrude in the direction along the fluid flow are defined as mountain portions 24, and the portions that recess in the opposite direction to the fluid flow are defined as valley portions 25.

[0029] As described above, as the contact area between the corrugated fins 2 and the cooling fluid increases, the number of through holes 21... provided in the fluid flow path 5 also increases, making it possible to efficiently dissipate heat into the fluid passing through the through holes 21..., while at the same time reducing the flow rate of the fluid passing through each of the through holes 21..., thereby making it possible to suppress pressure loss of the fluid. Therefore, the cooling performance of the heat sink can be fully exerted without using a powerful fan, and problems such as increased power consumption and noise generation can be avoided.

[0030] In addition, instead of the corrugated plate-like fin 2 consisting of a continuum of semicircular mountain portions 24 and semicircular valley portions 25 as described above, a corrugated plate-like fin having a cross-sectional shape curved like a sine curve, or a cross-sectional shape consisting of a continuum of oval mountain portions and valley portions, or a cross-sectional shape consisting of a continuum of triangular mountain portions and valley portions may be used.

[0031] Also, instead of the first embodiment described above in which each through hole 21 is formed to extend in the thickness direction of the corrugated plate-like fin 2, a structure in which a plurality of through holes inclined at a certain angle with respect to the thickness direction of the corrugated plate-like fin 2 may be provided. However, when a plurality of through holes 21 are formed to extend in the thickness direction of the corrugated plate-like fin 2 as shown in the first embodiment described above, the cooling fluid can flow evenly and smoothly along each through hole 21. As a result, the flow resistance of the cooling fluid passing through each through hole 21 can be reduced, the pressure loss can be suppressed, and heat can be efficiently dissipated into the fluid.

[0032] In the first embodiment described above, a plurality of corrugated fins 2 are arranged with their plate surfaces facing each other at intervals, and a cooling fluid is sequentially supplied toward the plate surface 20 of each corrugated fin 2 and flows along each of the through holes 21.... According to this configuration, heat transferred from the heat absorbing portion 3 to each corrugated fin 2 is sequentially dissipated into the fluid passing through the through holes 21... of each corrugated fin 2, and is cooled stepwise, so that the cooling performance of the heat sink can be sufficiently ensured without taking measures such as increasing the width dimension (installation height) of the corrugated fin 2. Therefore, it is possible to install the heat sink even in a place with a small space, and there are advantages such as being able to make the heat sink thinner and more compact than conventional heat sink structures.

[0033] Furthermore, as shown in the first embodiment described above, when multiple corrugated fins 2 are arranged parallel to each other at a certain interval, that is, as shown in Figure 3, with the mountain-shaped portions 24, 24 and the valley-shaped portions 25, 25 of adjacent corrugated fins 2, 2 facing in the same direction, it is possible to arrange each corrugated fin 2 at an appropriate interval while preventing contact between the mountain-shaped portions 24 and the valley-shaped portions 25 of adjacent corrugated fins 2, 2.

[0034] Furthermore, in the above embodiment, the lotus-type porous metal molding having a plurality of pores extending in one direction formed by a metal solidification method is cut in a direction intersecting the extending direction of the pores to form the plate-shaped material 2a, and then the plate-shaped material 2a is bent into a wave shape to form the corrugated fins 2, so that the corrugated fins 2 can be easily manufactured at lower cost than when a plurality of through holes are machined by drilling or the like. Moreover, since the skin region 23 is formed around the corrugated fins 2 as described above, the bonding area between the heat absorption parts 3, 4 and each of the corrugated fins 2 is secured, sufficient bonding strength can be maintained, and there is also the advantage that heat can be efficiently transferred from the heat absorption parts 3, 4 to the corrugated fins 2.

[0035] Second Embodiment A second embodiment of the heat sink structure according to the present invention will be described with reference to Fig. 4. The heat sink structure 1a according to the second embodiment includes a heat absorbing section made of a heat pipe 30 configured to transfer heat by vacuum sealing a working fluid in a copper tube and circulating the working fluid by generating convection according to the temperature difference between both ends, and a plurality of corrugated fins 2 made of a continuum of semicircular mountain portions 24 and semicircular valley portions 25 having a curvature radius corresponding to the heat pipe 30.

[0036] The corrugated fins 2 are arranged in parallel at intervals corresponding to the diameter of the heat pipe 30, and the heat pipe 30 is disposed between the opposing corrugated fins 2, 2. A semicircular portion located on one side of the heat pipe 30 is joined to the inner circumferential surface of the mountain-shaped portion 24, and the other side of the heat pipe 30 is joined to the outer circumferential surface of the valley-shaped portion 25. This allows the heat of the working fluid moving inside the heat pipe 30 to be transferred from the heat pipe 30 to the corrugated fin 2. In addition, the fluid blown through the fluid flow path 5 is sequentially supplied to the plate surface 20 of each corrugated fin 2, and the fluid flows along the through holes 21 of each corrugated fin 2, and the heat of the corrugated fin 2 is dissipated into the fluid, thereby exerting the cooling effect of the heat sink.

[0037] In this way, when the corrugated fin 2 is formed as a continuum of the circular mountain portion 24 and the semicircular valley portion 25, and the radii of curvature of the mountain portion 24 and the valley portion 25 are set to values ​​corresponding to the heat pipe 30, the heat pipe 30 and the corrugated fin 2 can be firmly joined by brazing or the like with the peripheral surface of the heat pipe 30 tightly aligned with the inner peripheral surface of the mountain portion 24, and heat can be efficiently transferred from the heat pipe 30 to the corrugated fin 2.

[0038] As shown in Fig. 4, instead of the second embodiment in which the semicircular portion located on one side of the heat pipe 30 is joined along the inner peripheral surface of the mountain portion 24 and the other side of the heat pipe 30 is abutted against the outer peripheral surface of the valley portion 25, the mountain portion 24 and the valley portion 25 of a pair of adjacent corrugated fins 2, 2 may be arranged to face each other, and the heat pipe 30 may be disposed and joined between the mountain portion 24 and the valley portion 25 as shown in Fig. 5. According to the heat sink structure 1b configured in this way, the contact area between the heat pipe 30 and the corrugated fin 2 can be increased, and the heat pipe 30 and the corrugated fin 2 can be joined more firmly, and heat can be transferred from the heat pipe 30 to the corrugated fin 2 more efficiently.

[0039] 6, a pair of adjacent corrugated fins 2, 2 may have peaks 24 and valleys 25 facing each other, and a heat pipe 30 may be disposed between the peaks 24 and valleys 25 to form a plurality of heat sink units 10... which are then joined together and stacked together. According to the heat sink structure 1c configured in this manner, the number of corrugated fins 2 can be easily increased as necessary, thereby significantly increasing the amount of heat dissipated into the fluid flowing along the through holes 21... of each corrugated fin 2.

[0040] Although the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and may be embodied in various forms without departing from the spirit and scope of the present invention, such as a water-cooling or liquid-cooling system in which a cooling fluid made of a cooling liquid is circulated. [Explanation of symbols]

[0041] 1. Heat sink structure 2. Corrugated fins 2a Plate material 3,4 Heat sink 5 Fluid Flow Path 10 Heat sink unit 8 Electronic Board 9. Cooling Object 20 Board surface 21 Through hole 23 Skin Area 24 Yamagata 25 Tanigata section 30 Heat Pipe

Claims

1. A plurality of corrugated metal fins each having a cross-sectional shape formed in a wave shape, which is a continuation of mountain-shaped and valley-shaped portions, and each having a plurality of through holes opening into the plate surface; a heat absorbing portion that absorbs heat from an object to be cooled and transfers the heat to each of the corrugated fins; a fluid flow path for supplying a cooling fluid toward a plate surface of the corrugated fin in a direction parallel to a protruding direction of a peak portion and a recessed direction of a valley portion, thereby causing the fluid to flow along the through holes, The plurality of corrugated fins are arranged in parallel at regular intervals with their plate surfaces facing each other, The fluid flow path sequentially supplies the fluid to the plate surfaces of the corrugated fins, a heat sink structure in which heat transferred from the heat absorption portion to each of the corrugated fins is dissipated into a fluid passing through the through hole of each of the corrugated fins, The corrugated fin has a cross-sectional shape that is a continuation of a semicircular mountain portion and a semicircular valley portion, The heat absorbing portion is a heat pipe, the peaks and valleys have a radius of curvature corresponding to the heat pipe; The heat pipe is joined along the inner circumferential surface of at least one of the peak-shaped portion and the valley-shaped portion, forming a heat sink structure.

2. 2. The heat sink structure according to claim 1, wherein the through holes extend in a thickness direction of the corrugated fins.

3. A plurality of the corrugated fins are arranged at intervals with their plate surfaces facing each other, 3. The heat sink structure according to claim 1, wherein the fluid is supplied sequentially toward the plate surfaces of the corrugated fins.

4. The heat sink structure according to any one of claims 1 to 3, wherein the corrugated fin is a bent piece of a lotus-type porous metal molding having multiple pores extending in one direction and formed by a metal solidification method.

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