Heat sink for an electronic component, and corresponding cooling arrangement

Abstract

The invention relates to a heat sink for at least one microchip, comprising a thermally conductive heat sink which has a channel structure for a cooling fluid, which channel structure has a supply and a return, characterised in that the heat sink comprises a cooling plate on each of two opposing outer faces, which cooling plate is thermally and mechanically coupled to the channel structure. The invention also relates to a corresponding cooling arrangement.

Description

[0001] Heat sink for an electronic component and a corresponding cooling arrangement

[0002] The invention is based on a heat sink, frequently also called a "cold plate," for at least one electronic component, comprising a heat-conducting heat sink having a channel structure for a cooling fluid with a supply and a return line. Such a heat sink is described in US 10,485,143 B2. A heat sink having the features of the preamble of claim 1 is disclosed in US 2009 / 0114373 Ai. Similar arrangements are also described in JP 4027353 B2 and EP 2386 194 Bi. Further cooling elements are also disclosed in US 2010 / 0084120 Ai and DE 212012 000 233 Ai.

[0003] As the computing power of many electronic components, such as IT components such as microchips (CPUs, GPUs, etc.), inverters, and the like, increases, so does their power dissipation and thus their heat generation. Progressive advancements in microchip technology, for example, enable power levels of more than 400 watts per chip. Due to the increased power density, conventional air-cooled heat sinks and heat sinks are no longer suitable for adequately dissipating the resulting power dissipation, given the limited space available in server enclosures, for example. New cooling technologies, such as "direct chip cooling," do make it possible to cool microchips effectively. However, these technologies are significantly more complex and comparatively less resilient to failure than conventional heat sinks.Even the heat pipes known from the prior art, based on copper tubes and aluminum fins, have only limited cooling capacity. Fundamentally, the goal is to maximize the performance of electronic components while offering a product at the lowest possible cost. One way to reduce infrastructure and its costs is to better utilize the available space on the server and increase the server's computing power without thereby increasing the available volume. This also makes it possible to upgrade existing data centers with higher computing power, given a given space requirement. It is therefore the object of the invention to further develop a heat sink of the type described above in such a way that it provides high cooling performance with a small space requirement.

[0004] This object is achieved by a heat sink having the features of claim 1. The subordinate claim 13 relates to a corresponding cooling arrangement.

[0005] Accordingly, a heat sink is provided with a cooling plate on each of the opposing outer sides, which is thermally coupled to the channel structure. The invention is therefore based on the idea of ​​designing the heat sink in a plate-shaped, i.e., flat, manner, unlike the heat sinks known from the prior art, in order to provide the largest possible surface area for the conductive heat transfer from an electronic component requiring cooling to the heat sink, while maintaining a small dimension perpendicular to the opposing outer sides.

[0006] As a result, not only one of the two opposite outer sides of the heat sink can be used for cooling an electronic component requiring cooling, but both sides can preferably be used for cooling at least one electronic component. With respect to the two outer sides comprising the cooling plates, the heat sink, in particular its heat-conducting heat sink, can be designed symmetrically, so that the heat sink has an identical cooling plate for the thermal coupling of an electronic component requiring cooling in two positions rotated by 180° to each other.

[0007] If the channel structure of the heat sink is thermally coupled to both of the cooling plates arranged on the opposite outer sides, the cooling power provided by the heat sink is provided equally by both cooling plates. The heat sink can thus also be designed symmetrically with regard to the channel structure with respect to the two cooling plates. For example, the heat sink can be fully symmetrical with respect to a center plane of the heat sink, which extends parallel to the two cooling plates. The supply and return lines can be arranged on a front side of the heat sink oriented perpendicular to the cooling plates, so that they do not represent an interfering structure with respect to the mounting of electronic components requiring cooling on the opposite cooling plates.When a cooling fluid is described in the present application, this can be a single-phase, but also a multi-phase, in particular a two-phase cooling fluid with a liquid phase and a vapor phase, for example a cooling fluid that has a vapor phase.

[0008] In order to provide a particularly good thermal conductivity of the heat sink and thus the most uniform distribution of the cooling power possible over the volume of the heat sink or over the surface of the at least one cooling plate, the heat sink, in particular at least the at least one cooling plate and the channel structure, can be formed in one piece in an additive manufacturing process, for example by means of build-up welding.

[0009] The channel structure can be meandering and run through the heat sink parallel to at least one or both cooling plates. To achieve the greatest possible channel structure length, the channel structure can have at least two channel sections that extend through the heat sink substantially parallel to one another and preferably as densely packed as possible. At least one fluidic transition can be provided between the at least two channel sections on opposite end faces of the heat sink, within which fluidic transition successive of the at least two parallel channel sections are connected to one another via an 180° deflection to form the meandering channel structure.

[0010] The channel structure preferably consists of a plurality of channel sections that are connected to one another via fluidic transitions, wherein at least one of the channel sections consists, at least in sections, of a plurality of sub-channels that are fluidically separated from one another along the channel section. The sub-channels can in particular extend parallel to one another. The sub-channels can be fluidically separated from one another by partition walls. The partition walls can be thermally coupled on opposite longitudinal sides to at least one or both of two opposing cooling plates, preferably formed integrally with the cooling plate or plates, in order to achieve optimal heat transfer between the at least one cooling plate and the fluid flowing through the sub-channels. Consequently, the partition walls themselves are preferably made of a thermally conductive material.If a thermal transition is provided between the partition walls and at least one cooling plate, the partition walls can contribute to the heat exchange to the fluid flowing through the sub-channels.

[0011] The separate subchannels can each be thermally coupled to both cooling plates. Thus, the subchannels can extend directly to the opposing cooling plates, so that a fluid flowing through the subchannels is in thermal contact with the cooling plates.

[0012] The partial channels can extend at least partially, preferably at least entirely, over a complete distance between the two cooling plates.

[0013] The channel section with the multiple sub-channels fluidically separated from one another along the channel section can flow directly into the fluidic transition with all of the sub-channels. It is therefore not necessary for the sub-channels to be merged before they flow into the fluidic transition. The fluid flows separated from one another by the sub-channels can only merge at the fluidic transition. Thus, in the flow direction, all of the sub-channels of the channel section feeding the transition, as well as all of the sub-channels of the channel section fed from the fluidic transition, can flow into the fluidic transition. The transition can be formed as a recess near an end face of the heat sink, into which all of the aforementioned sub-channels of the feeding and fed channel sections flow.

[0014] The channel structure can have a plurality of channel sections, which at least in sections consist of a plurality of sub-channels that are fluidically separated from one another along the respective channel section. The channel sections preferably have a different number of sub-channels. It is particularly preferably provided that, in the flow direction from the supply line to the return line, a second channel section following a first of the channel sections has a greater number of sub-channels than the first channel section. The increase in the number of channels in each channel section is designed to compensate for the increase in volume of the cooling medium due to the evaporation of the liquid. The more liquid transforms into the gaseous state, the more volume it occupies in order to keep the pressure loss in the channels essentially constant. When using a liquid medium such as water, there is no need to increase the number of channels in each channel section.In particular, the sum of the channel cross-sections of the sub-channels of the first channel section can be smaller than the sum of the channel cross-sections of the sub-channels of the second channel section. In this case, the aim can be to keep the cooling fluid velocity and thus the pressure loss constant. With a cooling fluid consisting essentially of a liquid phase, the flow velocity in the second channel section decreases with respect to the first channel section, so that due to the longer residence time of the cooling fluid in the second channel section in conjunction with the enlarged channel wall surface due to the increased number of sub-channels, a sufficient or constant cooling performance is still provided even if the cooling fluid temperature has increased compared to the first channel section.The increasing number of sub-channels and the resulting increased flow cross-section of the channel section compared to a preceding channel section in the flow direction can also serve to compensate for an increase in the volume of the refrigerant used, particularly when it is a 2-phase refrigerant which, as it passes through the heat sink and the heat transfer to the refrigerant increases, changes from the liquid phase to the gaseous phase with increasing proportion and accordingly occupies a larger volume.

[0015] The channel sections can have a number of sub-channels that continuously increases from channel section to channel section in the flow direction from the supply line to the return line.

[0016] The sub-channels of all channel sections can run parallel to one another, wherein the sub-channels preferably have a constant and particularly preferably a substantially equal or identical channel cross-section for all sub-channels.

[0017] The channel section opening into the return flow, and thus a terminal section in the direction of flow, can have a channel width which is at least twice, preferably at least three times and particularly preferably at least four times the width of the channel section opening into the flow flow.

[0018] The return line can have a cross-section at least twice as large, preferably at least three times as large, and particularly preferably at least four times as large as the supply line. This ensures optimal removal of the heated fluid from the heat sink, even at low fluid pressures or low flow velocities.

[0019] According to another aspect, a cooling arrangement comprising at least one heat sink of the type described above and at least two electronic components is described. The heat sink has a cooling plate on each of its two opposite outer sides. It is provided that the electronic components, with their heat-dissipating sides facing each other, are in thermal contact with the opposite outer sides of the cooling plate.

[0020] The electronic components and the opposite outer sides of the cooling plates may have complementary fastening means, preferably through holes and threaded receptacles.

[0021] It can be provided that the heat sink with the electronic components mounted on it on the opposing cooling plates represents a pre-assembled module, for example a pre-assembled module of a larger IT unit, e.g. a server chassis, in which it is mounted, for example by inserting the two electronic components into slots on a motherboard via connectors. The heat sink forms a supporting structure for the electronic components. The heat sink is therefore particularly suitable for retrofitting existing IT infrastructures, since by inserting the electronic components already pre-mounted on the heat sink, the electronic components are retrofitted and liquid cooling is provided in a single assembly step.

[0022] The electronic components can be designed as plug-in cards, wherein the plug-in cards can have a connector along an outer edge for vertical mounting and electrical connection of the electronic components, each with a separate slot of a plurality of slots on a motherboard. The distance between the outer sides of the heat sink can be precisely dimensioned so that the two electronic components have a distance between their connectors that corresponds to a grid spacing of the plurality of slots. Further details of the invention are explained with reference to the accompanying figures. Here:

[0023] Figure i shows a perspective view of an exemplary embodiment of a heat sink according to the invention;

[0024] Figure 2 is a sectional view of the heat sink according to Figure 1;

[0025] Figure 3 is a detailed view of the heat sink according to Figure 2;

[0026] Figure 4 shows the heat sink according to Figure 2 in perspective view;

[0027] Figure 5 is a detailed view of the heat sink according to Figure 4;

[0028] Figure 6 shows a perspective view of another exemplary embodiment of a heat sink according to the invention;

[0029] Figure 7 is a sectional view of the heat sink according to Figure 6;

[0030] Figure 8 shows a schematic representation of a cooling arrangement according to the invention;

[0031] Figure 9 is a detailed view of the cooling arrangement according to Figure 8; and

[0032] Figure 10 is a side view of the cooling arrangement according to Figure 8;

[0033] Figure 1 shows an exemplary embodiment of a heat sink 1 according to the invention. The heat sink 1 essentially consists of a thermally conductive heat sink 2, which has a channel structure for a cooling fluid inside, which is fluidically accessible via a supply line 4 and a return line 5 on one end face of the heat sink 2. In contrast to the heat sinks known from the prior art, the heat sink 2 has a cooling plate 6 on each of its two opposite outer sides, which are thermally coupled via the channel structure inside the heat sink 2 and are thus each supplied with cooling power. Both cooling plates 6 can thus be brought into thermal contact for the installation of an IT component requiring cooling, for example, a CPU or a GPU, for example by mounting the said electronic component with a heat-emitting side directly on the cooling plate 6.

[0034] Figures 2 to 5 show in particular the channel structure 3, which is formed in the interior of the heat sink 2 and is thermally and mechanically coupled to the two opposite cooling plates 6 of the heat sink 2.

[0035] The channel structure 3 consists of channel sections 7 extending parallel to one another, which extend in a meandering shape and parallel to the cooling plates 6 through the heat sink 2. The channel sections 7 are each divided into a plurality of sub-channels 8. The sub-channels 8 of the same channel section 7 are fluidically insulated from one another by partition walls 9 separating the sub-channels, so that no fluid exchange occurs between the sub-channels along the course of the sub-channels 8. All sub-channels 8 of the same channel section 7 open into a fluidic transition 10 at one end of the heat sink 2, where the partial volume flows of the sub-channels 8 are then combined. Furthermore, the combined partial volume flows are deflected by 180° in the fluid flow direction in the transition 10 and transferred to a subsequent channel section 7, wherein the volume flow is in turn divided among a plurality of sub-channels 8.

[0036] As can be seen, the channel structure 3 has four channel sections 7, each of which is divided into a different number of sub-channels 8. In the fluid flow direction from the supply line 4 to the return line 5, each subsequent channel section 7 has a higher number of sub-channels 8 than the previous channel section 7 in the flow direction, with all sub-channels 8 of the heat sink 2 having the same opening cross-section. The increase in the number of sub-channels thus results in a reduction in the flow velocity at the transition to each subsequent channel section 7 in the flow direction. Furthermore, the number of partition walls 9 and the area of ​​the cooling plates 6 with which the channel section or the fluid passing through the channel section is in thermal contact are increased, whereby a substantially constant cooling performance with respect to the cooling plates 6 can be provided even with increasing cooling fluid temperature.Figure 3 further illustrates that the partition walls 9 are formed integrally with the cooling plate 6, for example, using an additive manufacturing process. Furthermore, the partition walls 9 have a surface structure 12 on their inner sides facing the sub-channel 8, whereby the effective cross-section between the cooling fluid and the partition wall can be increased and, if necessary, turbulence can be generated to improve the heat exchange between the cooling fluid and the partition walls 9. Since the partition walls 9 merge directly into the cooling plates 6 or can even be formed integrally with the cooling plates 6, optimal heat transfer is achieved from the cooling plate 6 via the partition walls 9 and the surface structure 12 to the cooling fluid flowing through the sub-channels 8.

[0037] Figures 4 and 5 illustrate that the fluidic transitions 10 can be designed as recesses which are particularly advantageous for construction using an additive manufacturing process, wherein all sub-channels 8 of the two channel sections 7 fluidically connected to one another via the transition 10 open into the transition 10.

[0038] Figures 6 and 7 show a further embodiment of a heat sink 1 according to the invention, which, in contrast to the previously described embodiments, has a cooling plate 6 on only one of its two opposite sides and a supply line 4 and a return line 5 on the side opposite the cooling plate 6. The cross-section according to Figure 7 further illustrates the preferred one-piece design of the heat sink 1, whereby, on the one hand, optimal heat transfer between the heat sink 1 and the cooling fluid flowing through the heat sink 1 and, on the other hand, optimal heat distribution within the heat sink 1 is achieved, thus making the entire heat capacity of the heat sink 1 available for heat transfer from an electrical component requiring cooling to the heat sink 1. The heat sink 1 according to Figures 6 and 7 is preferably manufactured using an additive process, which ensures the aforementioned one-piece design.

[0039] Figures 8 to 10 describe an embodiment of a cooling arrangement according to the invention, in which an electronic component 100, here a GPU, is mounted, for example screwed, on opposite outer sides forming the cooling plates 6 (see Figure 1), so that the electronic component 100 is in heat-transferring contact with one of the two opposing cooling plates 6. The IT components 100 are designed as plug-in cards, which can be mounted in corresponding slots 201 on a motherboard 200 for installation in a server housing 300, as is known from the prior art.Deviating from the prior art, the heat sink 1 according to the invention enables two IT components 100, with the heat sink 1 positioned between them, to form a pre-assembled assembly that can be mounted in a single assembly step, namely by inserting the connectors 102 of the two IT components 100 into one of the slots 201 in the housing 300 or on the motherboard 200, without requiring any further assembly steps to provide cooling for the IT components. If necessary, it is only necessary to connect the supply line 301 and the return line 302 to the supply line and the return line of the heat sink 1, respectively.

[0040] Particularly advantageously, the heat sink 1 thus has a dimension perpendicular to the two cooling plates 6, which, when the IT components 100 are mounted on the cooling plates 6, defines a distance to the two connectors 102 of the IT components 100, which corresponds to the distance between the two slots 201 or a grid spacing of the plurality of slots 201.

[0041] The heat sink 1 and the IT components 100 can have complementary fastening means, via which the IT components can be force-fitted to the heat sink 1 to form a one-piece unit. For example, the IT components 100 can have through-holes 101 and the heat sink 1 can have threaded holes 11, by means of which the IT components 100 can be screwed to the heat sink 1.

[0042] Figure 10 illustrates that, with the aid of the heat sink 1 according to the invention, a maximum packing density of the IT components 100 in the server housing 300 can be achieved. In particular, the heat sink 1 can have a dimension perpendicular to the cooling plates 6 that is precisely dimensioned such that, for a given grid dimension of the slots 201 according to the industry standard and with the IT components 100 mounted in these slots 201 with their heat-dissipating sides facing each other, the heat sink 1 just fills the remaining space between the heat-dissipating sides of the facing IT components 100, thus ensuring not only optimal space utilization but also optimal heat transfer between the components 100 and the heat sink 1.

[0043] List of reference symbols:

[0044] heat sink

[0045] heat sink

[0046] Channel structure

[0047] Lead-up

[0048] Return

[0049] Cooling plate

[0050] Canal section

[0051] Partial channel

[0052] partition

[0053] transition

[0054] Threaded mount

[0055] Surface structure of electronic component

[0056] Through hole

[0057] connectors

[0058] motherboard

[0059] slot

[0060] Server chassis

[0061] flow line

[0062] Return line

Claims

Claims: A heat sink (1) for at least one microchip (100), preferably a GPU or CPU, comprising a thermally conductive heat sink (2) having a channel structure (3) for a cooling fluid with a supply (4) and a return (5), characterized in that the heat sink (2) has a cooling plate (6) on each of two opposite outer sides, which is thermally and mechanically coupled to the channel structure (3). A heat sink (1) according to claim 1, wherein the channel structure (3) is meandering and parallel to the at least one cooling plate (6) or to both cooling plates. (6) is guided through the heat sink (2). Heat sink (1) according to one of the preceding claims, wherein the channel structure (3) consists of several channel sections (7) which are connected to each other via fluidic transitions (10), wherein at least one of the channel sections (7) consists at least sectionally of several sub-channels (8) which are fluidically separated from each other along the channel section (7). Heat sink (1) according to claim 3, wherein the separated sub-channels (8) are thermally coupled to the at least one cooling plate (6) or to both cooling plates (6), wherein the sub-channels (8) are preferably fluidically separated from each other by partitions (9) which are thermally and mechanically coupled to the at least one cooling plate or to both cooling plates (6) and are particularly preferably formed integrally with the at least one cooling plate or with both cooling plates (6).A heat sink (1) according to claim 3 or 4, wherein the partial channels (8) extend at least partially and preferably entirely over a complete distance between the two cooling plates (6), if the heat sink (2) has a cooling plate (6) on each of its opposite outer sides. A heat sink (1) according to any one of claims 3 to 5, wherein the channel section. (7) with the several along the canal section (7) fluidically from each other separate sub-channels (8) with all sub-channels (8) opening directly into the fluidic transition (10). - Heat sink (i) according to one of claims 3 to 6, in which the channel structure (3) has several channel sections (7) which at least sectionally consist of several sub-channels (8) fluidically separated from one another along the respective channel section (7), wherein the channel sections (7) have a different number of sub-channels (8). . Heat sink (1) according to claim 7, in which, in the flow direction from the inlet (4) to the outlet (5), a second channel section (7) following a first channel section (7) has a larger number of sub-channels (8) than the first channel section (7). . A cooling element (1) according to claim 7 or 8, wherein the channel sections (7) have a continuously increasing number of sub-channels (8) in the flow direction from the supply (4) to the return (5).A heat sink (1) according to claims 2 to 8, wherein the sub-channels (8) of all channel sections (7) run parallel to one another, the sub-channels (8) preferably having a constant and particularly preferably a channel cross-section that is substantially the same or identical for all sub-channels (8).

1. A heat sink (1) according to claims 2 to 9, wherein a channel section (7) opening into the return (5) has a channel width that is at least twice, preferably at least three times, and particularly preferably at least four times the width of the channel section (7) opening into the supply (4).

2. A heat sink (1) according to claims 2 to 9, wherein the return (5) has a cross-section that is at least twice, preferably at least three times, and particularly preferably at least four times that of the supply (4). - Cooling arrangement with at least one heat sink (1) according to one of the preceding claims, wherein the heat sink (2) has a cooling plate (6) on each of its two opposite outer sides, and with at least two microchips (100) whose heat-emitting sides face each other and are in thermal contact with the opposite outer sides of the cooling plate (6). . Cooling arrangement according to claim 13, wherein the electronic components (100) and the opposite outer sides of the cooling plates (6) have complementary fastening means (11, 101), preferably through holes (101) and threaded receptacles (11). .Cooling arrangement according to claim 12 or 13, wherein the electronic components (100) are designed as plug-in cards, the plug-in cards having along an outer edge a connector (102) for the vertical mounting and electrical connection of the electronic components (100) with each a separate slot (201) of a plurality of slots (201) on a main board (200), wherein the distance of the outer sides of the heat sink (2) is dimensioned such that the two electronic components (100) have a distance between their connectors (102) which corresponds to a grid spacing of the plurality of slots (201).

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