Abstract
A heat sink for collecting thermal energy from a heat generating component. The heat sink comprises a base comprising a thermal transfer surface configured to be placed in thermal contact with the heat-generating component, an external surface opposite from the thermal transfer surface and an inlet side of the base extending between an edge of the thermal transfer surface and an edge of the external surface and a plurality of fins extending from the external surface. The fins define a plurality of fin passages therebetween, at least one fin of the plurality of fins having non-straight longitudinal edges extending along the external surface and defining at least in part at least one non-straight fin passage.
Claims
1. A heat sink for collecting thermal energy from a heat generating component, the heat sink comprising: a base comprising: a thermal transfer surface configured to be placed in thermal contact with the heat generating component, and an external surface opposite from the thermal transfer surface; and a plurality of fins extending from the external surface, wherein at least two adjacent fins of the plurality of fins define a curved fin passage therebetween along the external surface.
2. The heat sink of claim 1, wherein the at least two adjacent fins extend from a first edge of the heat sink to a second edge of the heat sink, and wherein an end of the second edge extends from an end of the first edge.
3. The heat sink of claim 2, wherein the first edge is perpendicular to the second edge.
4. The heat sink of claim 1, wherein the heat sink is made of a material selected from copper, aluminum, an aluminum alloy and a combination thereof.
5. The heat sink of claim 1, wherein an inlet side of the base extends between an edge of the thermal transfer surface and an edge of the external surface, and wherein the curved fin passage directs cooling fluid flow from the inlet side to a corner of the heat sink.
6. A system for collecting thermal energy from a plurality of heat generating components by circulating heat transfer fluid, wherein the system comprising a first heat sink and a second heat sink, wherein the first heat sink comprises: a base comprising: a thermal transfer surface configured to be placed in thermal contact with a first heat-generating component of the plurality of heat generating components, and an external surface opposite from the thermal transfer surface; and a first plurality of fins extending from the external surface, wherein at least two adjacent fins of the first plurality of fins define a curved fin passage therebetween along the external surface, wherein the second heat sink comprises a second plurality of fins forming a plurality of fin passages, and wherein the curved fin passage of the first heat sink directs the heat transfer fluid to the plurality of fin passages of the second heat sink.
7. The system of claim 6, wherein the heat transfer fluid is an immersive cooling liquid, and wherein the first heat sink and the second heat sink are at least partially immersed in the immersive cooling liquid.
8. The system of claim 6, wherein the at least two adjacent fins extend from a first edge of the first heat sink to a second edge of the first heat sink, and wherein an end of the second edge extends from an end of the first edge.
9. The system of claim 8, wherein the first edge is perpendicular to the second edge.
10. A system for collecting thermal energy from a plurality of heat generating components by circulating heat transfer fluid, wherein the system comprising a first heat sink and a second heat sink, wherein the first heat sink comprises: a base comprising: a thermal transfer surface configured to be placed in thermal contact with a first heat-generating component of the plurality of heat generating components, and an external surface opposite from the thermal transfer surface; and a first plurality of fins extending from the external surface, wherein at least one of the first plurality of fins is configured with a continuous fin structure comprising a straight portion and an angled portion to define at least one non-straight fin passage, wherein the second heat sink comprises a second plurality of fins forming a plurality of fin passages, and wherein the at least one non-straight fin passage of the first heat sink directs the heat transfer fluid to the plurality of fin passages of the second heat sink.
11. The system of claim 10, wherein the heat transfer fluid is an immersive cooling liquid, and wherein the first heat sink and the second heat sink are at least partially immersed in the immersive cooling liquid.
12. The system of claim 10, wherein fin sections of two adjacent fins of the first plurality of fins divergently extend from one another along the external surface.
13. The system of claim 10, wherein fin sections of two adjacent fins of the first plurality of fins convergently extend towards one another along the external surface.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] For a better understanding of the present technology, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where:
[0027] FIG. 1 (prior art) is a front elevation view of a conventional heat sink;
[0028] FIG. 2 (prior art) is a top view of the conventional heat sink of FIG. 1;
[0029] FIG. 3 is a front elevation view of a heat sink in accordance with an embodiment of the present technology;
[0030] FIG. 4 is a top view of the heat sink of FIG. 3;
[0031] FIG. 5 is a perspective view of the heat sink of FIG. 3;
[0032] FIG. 6 is a top view of another heat sink in accordance with an embodiment of the present technology;
[0033] FIG. 7 is a top view of yet another heat sink in accordance with another embodiment of the present technology;
[0034] FIG. 8 is a schematic diagram of a cooling system comprising the heat sink of FIG. 7; and
[0035] FIG. 9 is a schematic diagram of another cooling system comprising the heat sink of FIG. 7.
DETAILED DESCRIPTION
[0036] Various representative embodiments of the disclosed technology will be described more fully hereinafter with reference to the accompanying drawings, in which representative embodiments are shown. The presently disclosed technology may, however, be embodied in many different forms and should not be construed as limited to the representative embodiments set forth herein. Rather, these representative embodiments are provided so that the disclosure will be thorough and complete, and will fully convey the scope of the present technology to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. Like numerals refer to like elements throughout. And, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the described embodiments pertain.
[0037] Generally speaking, a heat sink is a passive heat exchanger that may be disposed on a heat generating component (e.g. Computing Processing Units (CPUs), Graphics Processing Units (GPUs), chipsets or Random-Access Memory (RAM) modules) to be cooled. The heat sink defines a plurality of fins and transfers the thermal energy generated by the heat generating component to a cooling fluid (e.g. ambient air or fluid medium) flowing between said fins. Thermal energy is thus carried away from the device, thereby allowing regulation of the temperature of the heat generating component.
[0038] Referring now to the drawings, FIGS. 1 and 2 respectively illustrate a front elevation view and a top view of a conventional heat sink 10 disposed on a heat generating component 50, the heat sink 10 being configured for dissipating thermal energy of the heat-generating component 50. In this example, the heat-generating component 50 is a central processing unit (CPU) of a computer system and is mounted to a motherboard thereof (not shown). In use, the CPU 50 generates a significant amount of thermal energy and can benefit from cooling. It is contemplated that the heat-generating component 50 could be any other suitable heat-generating electronic component (e.g., a graphics processing unit (GPU)) or an intermediary component disposed between the heat sink 10 and a heat-generating component.
[0039] In use, the heat sink 10 is typically disposed atop the heat-generating component 50 and is in thermal contact with the heat-generating component 50 such as to allow the heat sink 10 to absorb thermal energy therefrom. The fins 20 are straight and extend in a depth direction of the heat sink 10. The cooling fluid typically flows between the fins 20 and collects thermal energy of the heat sink 10. Thermal energy is thus carried away from the heat generating component 50.
[0040] Given the geometry of the fins 20, the flow of the cooling fluid is limited to having a straight direction, which may cause undesirable turbulences in the flow of the cooling fluid. As an example, two heat sinks 10 disposed in a vicinity from each other may mutually obstruct the flow of the cooling fluid when the fins 20 of both heat sinks 10 are not extending along a same direction. As an example, the depth directions of the two heat sinks may be orthogonal due to mechanical constraints. In this situation, the cooling fluid flowing between the fins 20 of one heat sink 10 is at least partially blocked by the other heat sink 10.
[0041] With reference to FIGS. 3 to 5, a heat sink 100 is illustrated in accordance with one embodiment of the present technology. The heat sink 100 comprises a base 110 and a plurality of fins 120 extending from the base 110. A geometry of the fins 120 is described in greater details hereinafter. In this embodiment, the base 110 comprises a thermal transfer surface 130 on a first side of the heat sink 100 configured to be in thermal contact with the heat-generating component 50. It is to be understood that in this context, the thermal transfer surface 130 is said to be in thermal contact with the heat-generating component 50 either when the thermal transfer surface 130 is in direct contact with the heat-generating component 50 or when a thermal paste or any thermal interface material (TIM) is applied between the thermal transfer surface 130 and the heat-generating component 50, as long as adequate heat transfer is provided between the heat-generating component 50 and the thermal transfer surface 130.
[0042] The base 110 also comprises an external surface 140 on an opposite side of the base 110 from the thermal transfer surface 130. The external surface 140 is generally parallel to the thermal transfer surface 130 and faces in a direction opposite thereof. The fins 120 extend from the external surface 140, for example perpendicularly therefrom. With reference to FIG. 4, in this embodiment, the base 110 has front and rear longitudinal ends 130.sub.1, 130.sub.2, and opposite lateral ends 131.sub.1, 131.sub.2. In the context of the present disclosure, a depth direction of the heat sink 100 is defined between the front and rear longitudinal ends 130.sub.1, 130.sub.2. Besides, the cooling fluid is expected to enter fin passages 124 from the front longitudinal ends 130.sub.1 (e.g. a fluid inlet delivering the cooling fluid may be disposed in a vicinity of the heat sink 100 and towards the front longitudinal ends 130.sub.1). As shown, the fin passages 124 are external in that they are defined between fins 120 that extend away from the base 110. As such, the front longitudinal ends 130.sub.1 may be referred to as an inlet side 130.sub.1 of the fin passages 124 for receiving, in use, the cooling fluid.
[0043] In this embodiment, the base 110 and the fins 120 are made of a thermally conductive material such as metal, for instance copper, aluminum or aluminum alloys. However, it is contemplated that the base 110 and the fins 120 could be made from different thermally conductive materials in other embodiments, including combining different materials (e.g., the base 110 made from a different material than the fins 120). In a non-limiting embodiment, the fins 120 are laser-welded to the base 110. In another non-limiting embodiment, the fin passages 124 are machined into the external surface 140 to form the fins 120. For example, the fin passages 124 may be milled into the external surface 140 by a milling machine (e.g., a numerically controlled mill). The fin passages 124 may be provided in any other suitable way in other embodiments (e.g., molded or machined using electro erosion). Other configurations of the heat sink 100 are contemplated. For instance, the heat sink 100 may be formed of a mono-block body that may be made via 3D printing.
[0044] In this embodiment, as best shown on FIG. 4, some of the fins 120 are non-straight fins. More specifically, in this illustrative embodiment, each fin of a first set of fins 120.sub.1 comprises a first fin section extending from the inlet side 130.sub.1 in the depth direction, and a second fin section extending from the first fin section of the respective fin 120.sub.1 at an angle (). In the illustrative embodiment, of FIG. 3, each second fin section of the fins 120.sub.1 extend in a same direction. Alternative embodiments wherein the second fin sections of the fins 120.sub.1 extend in different directions forming, for example, different angles .sub.i are also contemplated. The second fin sections of the first set of fins 120.sub.1 extend at an angle 0<<180relative to the depth direction. As such, the second fin sections of the fins 120.sub.1 extends divergently with respect to the straight fins 120 of the heat sink 100.
[0045] Similarly, in this illustrative embodiment, each fin of a second of set of fins 120.sub.2 comprises a first fin section extending from the inlet side 130.sub.1 in the depth direction, and a second fin section extending from the first fin section of the respective fin 120.sub.2 at an angle (). In the illustrative embodiment, of FIG. 3, each second fin section of the fins 120.sub.2 extend in a same direction. Alternative embodiments wherein the second fin sections of the fins 120.sub.2 extend in different directions forming, for example, different angles .sub.i are also contemplated. The second fin sections of the second set of fins 120.sub.2 extend at an angle =<0 relative to the depth direction. The absolute value of may be different from in alternative embodiments (0<||<180).
[0046] In the illustrative embodiment of FIGS. 3 to 5, the first set of fins 120.sub.1 may thus orient the cooling fluid flowing within the fin passages 124 from the inlet side 130.sub.1 to an area in a vicinity of a corner of the heat sink defined by intersection of the rear ends 130.sub.2 and lateral end 131.sub.1. As such, the first set of fins 120.sub.1 may thus orient the cooling fluid to collect thermal energy from another heat generating component located near said corner. Similarly, the second set of fins 120.sub.2 may thus orient the cooling fluid flowing within the fin passages 124 from the inlet side 130.sub.1 to an area in a vicinity of a corner of the heat sink defined by intersection of the rear ends 130.sub.2 and lateral end 131.sub.2. As such, the second of set of fins 120.sub.2 may thus orient the cooling fluid to collect thermal energy from another heat generating component located near said corner. In this embodiment, as shown in FIG. 4, the length of each fin 120 corresponds to at least a majority of the length of the heat sink 100, the length of the heat sink 100 being defined along the depth direction. In another embodiment, one or more fins 120 may comprise a plurality of straight fin sections, each fin section extending at an angle relative to a successive straight fin section.
[0047] Summarily, the first and second sets of fins 120.sub.1, 120.sub.2 define non-straight fin passages 124 that may conduct or at least orient a flow of the cooling fluid towards other heat generating component located in a vicinity of the heat generating component 50. Therefore, the heat sink 100 with non-straight fins may collect thermal energy from the heat generating component 50 while guiding the cooling fluid in a vicinity of the heat generating component 50 in specific directions. A flow generator (e.g. a fan, a pump) of the cooling fluid may thus consume less energy to direct the cooling fluid towards the heat generating components to be cooled.
[0048] As best shown in FIG. 4, the angles between two straight fin sections of the first and second sets of fins 120.sub.1, 120.sub.2 are sharp, but filleted angles are also contemplated.
[0049] It is contemplated that a fluid (e.g., a refrigerant, a dielectric fluid or any fluid suitable for heat transfer purposes) other than air could be used to collect thermal energy from the heat sink 100 in some embodiments. For example, in some instance, the fluid may be an oil, an alcohol, or a dielectric fluid (e.g., 3M Novec).
[0050] With respect to FIGS. 6 and 7, alternative embodiments of the heat sink 100 are illustrated. More specifically, FIG. 6 illustrates the heat sink 600 having a set 610 of non-straight fins and a set 620 of straight fins. Each fin of the set 610 comprises a first fin section that is straight with respect of the heat sink 600 (i.e. extending along the depth direction) and a second fin section extending from the first fin section at an angle. In this illustrative embodiment, the second fin section extends inwardly with respect to the heat sink 600. In other words, it can be said that the second fin section converge towards the set 620 of straight fins. More specifically, in the illustrative embodiment of FIG. 6, the second fin section of a rightmost non-straight fin convergently extend towards a leftmost one of the straight fins along the external surface 140.
[0051] As an example, the heat sink 600 of FIG. 6 may be used to prevent the cooling fluid entering at an inlet side 630.sub.1 from being directed towards a vicinity of the corner defined by intersection of a rear ends 630.sub.2 and a lateral end 631.sub.1.
[0052] In the illustrative embodiment of FIG. 7, the fins 120 extend along an ellipsoidal pattern such that the external fluid entering the fin passages 124 at the inlet side 130.sub.1 is guided, in this example, towards the corner of the heat sink 700 defined by intersection of a rear end 730.sub.2 and a lateral end 731.sub.1. More specifically, in the illustrative embodiment of FIG. 7, the cooling fluid exits the fin passages 124 either at the rear end 730.sub.2 or at the lateral end 731.sub.1 with an orientation of the flow defining an angle with respect to the depth direction.
[0053] Referring back to FIG. 3 to 7, it should be understood that each one of the non-straight fins of the heat sinks 100, 600 and 700 may have a different geometry. Notably, a heat sink according to one non-limiting embodiment may comprise, for example, a first set of fins having a geometry similar to the fins 120.sub.1 of the heat sink 100, a second set of fins having a geometry similar to the fins 120.sub.2 of the heat sink 100, a third set of fins having a geometry similar to the fins 120 of the set 610 of the heat sink 600, a fourth set of fins having a geometry similar to the fins 120 of the heat sink 700 and/or a fifth set of straight fins. More generally, a heat sink according to one non-limiting embodiment may comprise any combination of fins having different geometries described herein without departing from the scope of the present technology.
[0054] FIG. 8 is a schematic diagram of a cooling system 2000 comprising an immersion cooling arrangement 2100. In this embodiment, the immersion cooling arrangement 2100 comprises a tank 2110 filled with a dielectric heat transfer fluid collecting thermal energy of the heat generating components 50 (shown on earlier Figures), the heat generating components 50 being disposed under respective heat sinks 700 and on a support board 30 (e.g. a Printed Circuit Board). As such, the heat generating components 50 and the heat sinks 700 are at least partially immersed in the dielectric heat transfer fluid. On FIG. 8, the shown heat sinks 700 are as described in the foregoing description of FIG. 7. It should be understood that heat sinks 100 or 600 as described in FIGS. 3-6 could alternatively be mounted on the heat generating components 50. A pump 2120 fluidly connected to the tank 2110 maintains a flow of the dielectric heat transfer fluid within the tank 2110. The pump 2120 may be external with respect to the tank 2110 or immersed within the tank 2110. A cooling apparatus (not shown) may be provided along an external fluid conduit 2210 to cool the dielectric heat transfer fluid. On the illustrative example of FIG. 8, the pump 2120 causes a flow of the dielectric heat transfer fluid from a surface of the tank 2110 to a bottom thereof such that the tank 2110 receives cooled dielectric heat transfer fluid at a tank inlet 2102. In alternative embodiments, the pump 2120 may be omitted, the flow of the dielectric heat transfer fluid being caused by natural convection. In such embodiments, the tank inlet 2102, the tank outlet 2104, and the external fluid conduit 2210 may also be omitted, and the dielectric heat transfer fluid may be cooled by other means (e.g. immersed coils connected to an external cooling loop of a second heat transfer fluid).
[0055] As illustrated by the white arrows on FIG. 8, a flow of the dielectric heat transfer fluid is at least in part directed by the two heat sinks 700 of the support board 30. More specifically, the dielectric heat transfer fluid entering the tank 2110 at the tank inlet 2102 is directed towards the support board 30 comprising the heat-generating components 50 to be cooled. The dielectric heat transfer fluid flows in the fin passages 124 of the fins 120 of a first heat sink 700, the first heat sink 700 being disposed to substantially extend along a vertical axis on FIG. 8. In the particular example of FIG. 8, in which the fins 120 of the heat sinks 700 are non-straight, the heat transfer fluid flow is directed from a substantially horizontal direction to a substantially vertical direction. Mounting the heat sinks of FIG. 4 or 6 in various orientations on the heat-generating components 50 could provide to direct the heat transfer fluid flow in the same or other directions. In the example as illustrated on FIG. 8, the warm dielectric heat transfer fluid may then flow in the fin passages 124 of the fins 120 of a second heat sink 700, the second heat sink 700 being disposed such that the inlet side 130.sub.1 thereof may receive the dielectric heat transfer fluid exiting the fin passages 124 of the first heat sink 700, the second heat sink 700 being disposed to substantially extend along a horizontal axis on FIG. 8. In this example, the heated dielectric heat transfer fluid that collected thermal energy from the first and second heat sinks 700 is thus directed towards a tank outlet 2104 by the fins of the second heat sink 700.
[0056] With reference to FIG. 9, a support board 40 is disposed within the tank 2110, the support board 40 comprising a first heat generating component 50 (not visible), the heat sink 700 of FIG. 7 disposed on the first heat generating component 50, and a second heat generating component 50. The second heat generating component 50 may be, for example, cooled via a channelized cooling liquid flowing in a conduit (not shown). As such, it may be desirable that the warm cooling fluid exiting the fin passages 124 of the heat sink 700 does not have thermal exchange with the second heat generating component 50. For example, a temperature of the cooling fluid exiting the fin passages 124 of the heat sink 700 may be above an operating temperature of the second heat generating component 50. The fins 120 of the heat sink 700 are thus positioned to orient a flow of the cooling fluid such that the latter is not directed towards the second heat generating component 50 upon exiting the fin passages 124. Dielectric cooling fluid that did not pass in the fin passages 124 of the heat sink 700 may collect thermal energy of the second heat generating component 50.
[0057] More specifically, the dielectric heat transfer fluid entering the tank 2110 at the tank inlet 2102 is directed towards the support board 40 as the flow of dielectric cooling fluid is maintained between the tank inlet 2102 and the tank outlet 2104 by the pump 2120. The dielectric heat transfer fluid flows in the fin passages 124 of the fins 120 of the heat sink 700, thereby being directed substantially away from the second heat generating component 50.
[0058] Modifications and improvements to the above-described embodiments of the present technology may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present technology is therefore intended to be limited solely by the scope of the appended claims.
