Device for cooling and data center

Abstract

The utility model relates to a device for cooling and a data center. Described is a device comprising a flow enhancing structure for enhancing the flow of a dip bath, in particular the flow of the dip bath through the spaces between the fins of the heat sink and / or through the base of the heat sink.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Patent Cooperation Treaty (PCT) application No. PCT / CN2023 / 093755 filed on May 12, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to cooling technology for electronic components. Background Art

[0004] As performance and power consumption in high performance computing environments, such as data centers, increase, system designers continue to seek ways to improve cooling techniques for the underlying electronic components that generate heat. Utility Model Content

[0005] In one aspect, an apparatus includes a flow enhancement structure for enhancing the flow of an immersion bath fluid, particularly the flow of the immersion bath fluid through spaces between fins of a heat sink and / or through a base of the heat sink.

[0006] In one embodiment, the flow enhancement structure comprises a suction conduit for returning the bathing liquid to the cooling distribution unit.

[0007] In one embodiment, the flow enhancement structure is adapted to receive a cooling fluid to be discharged into the bathing fluid after the bathing fluid flows through the flow enhancement structure.

[0008] In one embodiment, the flow enhancement structure comprises a bubble generating device.

[0009] In one embodiment, a bubble generating device is placed under the fins when an electronic circuit board having a semiconductor chip package coupled to a heat sink is immersed in a bathing fluid.

[0010] In one embodiment, when an electronic circuit board having a semiconductor chip package coupled to a heat sink is immersed in a bathing liquid, the bubble generating device is positioned to face the heat sink.

[0011] In one embodiment, the flow enhancement structure comprises a guide structure for guiding the position of the bubbles generated by the bubble generating device flowing within the bathing liquid.

[0012] In one embodiment, the bubble generating device is used to generate bubbles having a diameter in the range of 0.1 mm to 10 mm (inclusive).

[0013] In another aspect, an apparatus includes: an electronic component, the electronic component comprising: i) a frame; ii) an electronic circuit board mounted to the frame; iii) a semiconductor chip package coupled to the electronic circuit board; iv) a heat sink including fins, the heat sink coupled to the semiconductor chip package; v) a cover mounted to the frame and / or the electronic circuit board; vi) a flow enhancement structure for enhancing the flow of a bathing liquid, particularly the flow of the bathing liquid through the spaces between the fins and / or through the base of the heat sink when the component is immersed in the bathing liquid.

[0014] In one embodiment, the flow enhancement structure comprises a suction conduit for returning the bathing liquid to the cooling distribution unit, or the flow enhancement structure is for receiving cooling fluid to be discharged into the bathing liquid after the bathing liquid flows through the flow enhancement structure.

[0015] In one embodiment, the flow enhancement structure comprises a bubble generating device.

[0016] In one embodiment, the flow enhancement structure is integrated with the cover.

[0017] In one embodiment, the flow enhancement structure is mounted to the electronic circuit board and / or frame.

[0018] In one embodiment, the flow enhancement structure comprises an active device.

[0019] In another aspect, a data center includes: a network; multiple CPU pools coupled to the network; multiple memory pools coupled to the network; multiple storage pools coupled to the network; a chamber including an immersion fluid; an electronic unit located in the immersion fluid, the electronic unit being a component of one of the CPU pool, the memory pool, and the storage pool, the electronic unit including a flow enhancement structure for enhancing the flow of the immersion fluid, in particular the flow of the immersion fluid through the space between the fins of the heat sink and / or through the base of the heat sink, the heat sink being coupled to the semiconductor chip package of the electronic unit.

[0020] In one embodiment, the flow enhancement structure comprises a suction conduit for returning the bathing liquid to the cooling distribution unit, or the flow enhancement structure is for receiving cooling fluid to be discharged into the bathing liquid after the bathing liquid flows through the flow enhancement structure.

[0021] In one embodiment, the recirculated fluid flows over the lower liquid-free surface to increase the flow rate through the spaces between the fins.

[0022] In one embodiment, the flow enhancement structure comprises an active device.

[0023] In one embodiment, the flow enhancement structure comprises a bubble generating device.

[0024] In an embodiment, the flow enhancement structure is at least partially integrated with a cover of a component of the electronic unit and / or is at least partially mounted to an electronic circuit board and / or a frame of the electronic unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 depicts the immersion cooling system;

[0026] Figure 2a and Figure 2b depicts a circuit board submerged in an immersion chamber;

[0027] Figure 3 shows a printed circuit board having a flow enhancement structure near the fins of a heat sink;

[0028] Figure 4a , Figure 4b , Figure 4c and Figure 4d depicts an electronic unit assembly having a flow enhancement structure adjacent to the fins of a heat sink;

[0029] Figure 5a , Figure 5b , Figure 5c and Figure 5d involving a flow enhancing structure that also serves as a CDU return flow inlet;

[0030] Figure 6a , Figure 6b and Figure 6c A flow enhancing structure involving the generation of bubbles near the fins of a heat sink;

[0031] Figure 7 A data center environment is shown. DETAILED DESCRIPTION

[0032] Figure 1 An immersion cooling system is depicted. Figure 1 As shown, a plurality of electronic circuit boards 101 are immersed in a dielectric liquid 102, which electrically isolates the exposed electrical nodes of the electronic circuit boards 101 from their corresponding electronic components ( Figure 1 A side view depicting a circuit board 101 oriented vertically within a liquid 102. The electronic components generate heat when in operation, which is transferred to the liquid 102. The liquid 102 has a higher specific heat than air, which enables more efficient removal of heat from the electrical components than is achievable in an air-cooled environment.

[0033] The immersion chamber 103 is fluidly coupled to a coolant distribution unit (CDU) 104, which includes a pump 105 and a heat exchanger 106. During continued operation of the electronic components, the temperature of the liquid will increase due to the heat it receives from the operating electronic devices. The pump 105 draws the heated liquid 102 from the immersion chamber 103 to the heat exchanger 106. The heat exchanger 106 transfers heat from the heated fluid to a secondary liquid within a secondary cooling loop 107, which is fluidly coupled to a cooling tower and / or chiller unit 108. Removing heat from the liquid 102 by the heat exchanger 106 reduces the temperature of the liquid, which is then returned to the chamber 103 as cooled liquid.

[0034] In a high computing environment, such as a data center, respective CDUs of multiple immersion rooms are coupled to the secondary loop 107, and cooling towers and / or cooling units 108 remove heat generated by the electronics within the multiple immersion rooms from the data center.

[0035] As the performance of electronic components within the immersion fluid 102 increases and the corresponding heat dissipation increases, engineers and technicians continue to seek ways to increase the efficiency of heat transfer from the corresponding electronic components of the circuit board to the immersion fluid 102.

[0036] Figure 2a and Figure 2b A plurality of circuit boards 201 are depicted, which are immersed in a liquid 202 within an immersion chamber 203 ( Figure 2a A side view is shown, while Figure 2b 2. A top-down view is shown. It is noteworthy that the circuit board 201 is oriented vertically so that the high-performance semiconductor chip package and the corresponding faces of the fins 212 of the heat sink 211 coupled thereto are perpendicular to the horizontal x-axis (for ease of illustration, each circuit board 201 includes only one high-performance chip package and corresponding heat sink).

[0037] Ideally, the bathing fluid 202 exhibits a high velocity fluid flow through the heat sink fins 212 so that the large amounts of heat generated by one or more semiconductor chips operating within the underlying chip package can be efficiently transferred to the bathing fluid 202. Figure 2b , the special arrangement of the circuit board hinders the generation of this flow.

[0038] First, horizontal flow of the cooling fluid along the x-axis is substantially blocked by circuit board 201. Second, because the chamber walls, circuit board 201, and the circuit board's corresponding electronic devices and packaging introduce a large surface area over which fluid 202 will flow, fluid 202 will typically experience viscous forces that resist its flow throughout chamber 203 (viscous forces are proportional to the surface area of ​​the chamber walls, circuit board 201, and the circuit board's corresponding electronic devices and packaging).

[0039] Third, to some extent, attempts have been made to introduce high-speed flow, either horizontally along the y-axis or vertically along the z-axis, by placing various structures and / or components (e.g., baffles, nozzles) in the peripheral regions 213_1, 213_2 outside the circuit board 201. Unfortunately, in the case where the fluid is directed from the periphery 213_1, 213_2 toward the heat sink 211, the heat sink 211 may impose a flow impedance that causes the fluid to flow around the heat sink 211 rather than through their fins 212.

[0040] Finally, the bathing fluid 202 has a significant density and corresponding mass, causing the fluid 202 to experience a downward (-z) gravitational force that acts in opposition to the upward (buoyancy) fluid flow in the +z direction. The lack of upward fluid flow, combined with the viscous forces described above, causes flow stagnation and recirculation within the chamber 203, which in turn results in insufficient fluid flow (upward or otherwise) through the heat sink fins 212.

[0041] A solution (reference Figure 3 ) is to place a flow enhancement structure 321 near the heat sink 311, and the flow enhancement structure 321 generates a high-speed fluid flow that passes through the space between the heat sink fins 312 (also referred to as "through the fins"). In the case where the flow enhancement structure 321 is located near the heat sink 311 and / or the heat sink fins 312, the higher-speed fluid flow generated by the flow enhancement structure 321 will flow through the heat sink fins 312, thereby improving the heat transfer efficiency from the fins 312 to the liquid.

[0042] It is worth noting that in contrast to previous solutions, which typically only generally direct or increase fluid flow over multiple components, such as from the periphery 213 of the electronic circuit board (as described above with respect to Figure 2a and Figure 2b As described above, in contrast, the flow enhancement structure 321 is designed to direct and / or increase the flow particularly through the fins 312 of the heat sink 311.

[0043] Again, for ease of illustration, Figure 3 Only a single heat sink 311 is depicted on the circuit board 301 of FIG. 1 . It should be noted that other circuit boards may have multiple high-performance chip packages and a corresponding heat sink for each board. In this case, a corresponding flow enhancement structure 321 may be present near each heat sink (each board has multiple flow enhancement structures), and an enlarged flow enhancement structure 322 may be designed to enhance the flow through the corresponding fins of multiple heat sinks (and some combination thereof). Therefore, although the following description largely continues to present a single heat sink per circuit board, the reader should keep in mind that the teachings provided below can be easily extended to other types of circuit boards.

[0044] Figures 4a to 4d A more detailed embodiment is involved in which the printed circuit board is integrated into a larger assembly 400 before being immersed in the bath. As described in more detail below, assembly 400 can be a pluggable electronic unit that is inserted into an electrical / mechanical interface 433 (or a purely mechanical interface) within the bath.

[0045] Examples of such pluggable units include blade servers, CPU units, accelerator units, memory units, storage units, etc. Here, the functionality of the pluggable electronic unit largely corresponds to the functionality that the component's printed circuit board 401 is designed to perform or support (e.g., a computing system in the case of a blade server, one or more multi-core processor chips in the case of a CPU unit, one or more accelerators (e.g., one or more neural network chips, artificial intelligence machine learning chips, artificial intelligence inference engine chips, graphics processing unit (GPU) chips, etc.) in the case of an accelerator unit, multiple memory chips (e.g., multiple dual in-line memory modules (DIMMs)) in the case of a plurality of storage units, multiple storage devices (e.g., multiple solid-state drives (SSDs)) in the case of multiple storage units, etc.).

[0046] like Figure 4a and Figure 4b As shown, the assembly 400 includes a frame 431, a printed circuit board 401 and a cover 432 ( Figure 4a shows an exploded view, while Figure 4b The completed assembly is shown.) The printed circuit board 401 is mounted to the frame 431 (eg, using screws, bolts, or other types of fasteners), and the cover 432 is mounted to the printed circuit board 401 and / or the frame 431 .

[0047] The frame 431 mechanically supports the printed circuit board 401, while the cover 432 mechanically protects the printed circuit board and its electronic components from mechanical shock / blows that may be applied to the assembly 400, for example, during the insertion / removal of the assembly from the immersion liquid. It is worth noting that the frame 431 and the cover 432 have various perforations or other openings that allow fluid to enter the space where the printed circuit board 401 is located, so that the electronic components can be cooled by the flow of fluid through the assembly 400.

[0048] like Figure 4a and Figure 4b As shown in the specific embodiment of FIG. 4 , the flow enhancement structure 421_1 is integrated into the cover 432 of the assembly 400 near the heat sink 411 and / or the fins 412 of the heat sink.

[0049] In some other embodiments, Figure 4cAs shown in the side view of FIG. 4 , the flow enhancement structure 421_2 is composed of one or more structures and / or devices that are mechanically fixed (433) to the cover 432, the printed circuit board 401 and / or the frame 431. For example, the mechanical structure and / or active electrical components that enhance the flow through the heat sink fins 412 are mounted on posts extending from the printed circuit board 401 and / or the frame 431.

[0050] In still other embodiments, the flow enhancement structure is formed from a combination of elements formed in the cover 432 and individual elements mounted to any / all of the cover 432 , the printed circuit board 401 , and the frame 431 .

[0051] Figure 4d Another side view is provided, which shows that at least some of the flow enhancement structure 421_3 can extend beyond the cover 432 in the -x direction. However, here, in various embodiments, the "height" of the entire assembly along the x-axis is maintained within, for example, industry standard dimensions that specify the maximum dimension of the pluggable unit along the x-axis. For example, in the case of a pluggable electronic unit designed to conform to an industry standard format that specifies the maximum dimension along the x-axis in units of U, the extension of the flow enhancement structure 421_3 beyond the cover 432 does not cause the widest dimension of the assembly along the x-axis to exceed the maximum U dimension specified by the applicable standard along the x-axis.

[0052] Figure 5a to Figure 5d Various embodiments relate to flow enhancement structures 521 which not only increase the fluid flow rate through the fins of the underlying heat sink 511, but also act as a suction conduit for the liquid coolant returning to the CDU. Figure 5a , the flow enhancement structure 521 is coupled to a fluid channel 545 (eg, a hose, a pipe, etc.), which is coupled to a CDU fluid return channel 543 at an opposite end. Figure 5a and Figure 1 , CDU fluid return channel 543 corresponds to Figure 1 CDU return channel 109 in, or, corresponding to, feeding to Figure 1 The fluid passage in the CDU return passage 109 in the.

[0053] In various embodiments, the immersion bath includes a frame having a plurality of slots into which corresponding pluggable electronic units can be inserted. Figure 5a In a specific embodiment, each slot includes a pair of guide rails 546_1, 546_2 (guide rails 546_1 and 546_2 extend along the corresponding sides of the pluggable unit) and a backplane 541 into which the pluggable unit is physically inserted. The backplane 541 includes a first fluid connection 542 (e.g., a socket) that is aligned with a corresponding second fluid connection 548 (e.g., a nozzle) attached to the end of a fluid channel 545.

[0054] During installation of the pluggable unit, the pluggable unit enters the slot from the top of the immersion bath and is pressed down in the -z direction along the guide rails 546_1, 546_2 until it is inserted into the backing plate 541. As part of the installation into the slot, the first fluid connection 542 is connected to the second fluid connection 548, thereby fluidly coupling the channel 545 extending from the flow enhancement structure to the CDU return line 543.

[0055] exist Figure 5a During operation of the specific embodiment of the present invention, cooling fluid 544_1, 544_2 from the CDU is injected upward in the +z direction from below the pluggable unit. This upward injection causes a flow of cooling bath fluid that flows upward over the electronic components of the pluggable unit, but flows around the flow enhancement structure 521 covering the heat sink 511 (at Figure 5a In a specific embodiment, the bottom end of the flow enhancement structure 521 is shaped so that the upward flow bends around the structure 521).

[0056] The fluid continues to flow 544_1, 544_2 upwardly over the conduit 521. Due to suction from the CDU pumps and / or gravity, the submerged coolant streams 544_1, 544_2 are drawn into the suction conduit openings 547 of the flow enhancing structure 521. The fluids 544_1, 544_2 then flow through the flow enhancing structure 521 (ideally with high fluid velocity).

[0057] Here, the flow enhancement structure 521 is designed as a housing that surrounds the fins of the heat sink of the high-performance chip package 511, which is located directly below the flow enhancement structure 521. With the immersion coolant 544_1, 544_2 flowing through the flow enhancement structure 521 at high speed, and with the flow enhancement structure 521 constraining the fluid 544_1, 544_2 to flow through the space between the fins of the heat sink, heat is transferred from the heat sink fins to the immersion fluid 544_1, 544_2 with high efficiency (low thermal resistance).

[0058] It is worth noting that since the high-performance semiconductor chip(s) within the chip package below the heat sink 511 generates most of the heat of the pluggable unit, when the fluids 544_1, 544_2 flow around the flow enhancement structure 521 immediately after being injected into the immersion bath, they do not capture significant heat because the electronic devices through which the fluids 544_1, 544_2 flow / pass generate significantly less heat than the chips in the high-performance chip package below the heat sink 511. Therefore, when the fluid enters the intake duct 547, the temperature of the fluid should be relatively low (it is only slightly hotter than the temperature of the fluid entering the immersion bath from the CDU).

[0059] As described above, heat transfer from the radiator fins to the fluid within the flow enhancement structure 521 is more efficient as the fluid flow rate through the structure 521 increases. To increase the flow rate through the enhancement structure 521, the suction / intake from the CDU pump may be increased.

[0060] However, in other approaches, for example, to avoid overly powerful / expensive CDU pump equipment, the flow rate through the flow enhancement structure 521 is increased by establishing a sufficiently large height difference 553 between the upper surface of the coolant within the bath room 503 (upper liquid-free surface 551) and the opening 552 in the CDU return line 543 (lower liquid-free surface 552).

[0061] Specifically, Figure 5a As shown, immersion coolant flowing from immersion chamber 503 through return line 543 to the CDU flows through opening 552 in return line 543 and into plenum 549. Plenum 549 collects the fluid, and the CDU pump draws coolant from plenum 549 through return line 554 for cooling.

[0062] Importantly, openings 552 in return line 543 and openings in plenum 549 physically connect lower aneroid surface 552 to the same environment as upper aneroid surface 551. With this arrangement, gravity will cause the rate of fluid flow through enhancement structure 521 to increase as the height difference 553 between upper aneroid surface 551 and lower liquid free surface 552 increases. Thus, for example, by locating openings 552 in CDU return line 543 and plenum 549 sufficiently below bath room 503, extremely high flow rates through flow enhancement structure 521 may be achieved (e.g., without expensive / powerful CDU pump equipment).

[0063] It should be pointed out that Figure 5a The specific flow patterns 544_1, 544_2 and suction conduit arrangement 547 in FIG. 5 are only one example, and many other flow patterns and suction conduit arrangements are possible (e.g., the locations of the inlet / outlet of the liquid flowing into / out of the bath room and the flow enhancement structure 521 can be varied). For example, Figure 5b Another approach is shown, where the intake duct 547 faces the bottom of the bath. Here, liquid coolant 544_1, 544_2 is injected into the side of the pluggable unit along the y-axis and flows into the bottom intake duct opening 547 to return to the CDU. Figure 5c Another possible arrangement is shown, where there are multiple suction duct openings 547_1 , 547_2 on the side of the flow enhancing structure.

[0064] Figure 5dIt is also shown that the return lines from multiple flow enhancement structures on a single pluggable unit can feed fluid to each other, such as in a single fluid interface at the backplane. Specifically, Figure 561 shows an electronic circuit board 501 with two high-performance chip packages and corresponding flow enhancement structures 521_1, 521_2, while Figure 562 shows an electronic circuit board with four high-performance chip packages and corresponding flow enhancement structures 521_1, 521_2, 521_3, 521_4. In both Figure 561 and Figure 562, the CDU return from a set of flow enhancement structures flows into a common CDU return channel 545.

[0065] Note that the electromechanical interface may also be present at the backplane 541 and / or may be coupled to the pluggable unit through the upper surface of the bath 551. Figure 5a , Figure 5b and Figure 5c 541 ), the back plate 541 is simply a fixture at / near the bottom of the bath chamber 503 that aligns the pluggable unit's fluid connections 545 with corresponding connections 542 attached to the CDU return line 543. Thus, the back plate feature 541 does not necessarily have to extend end-to-end across the width of the electronics unit along the y-axis, but can be, for example, a simple mechanical fixture that merely holds and aligns the connections 542 (and perhaps provides mechanical support for the CDU return line 543).

[0066] and Figures 4a to 4d The discussion above is consistent with Figure 5a to Figure 5d Any flow enhancement structure 521 and / or fluid channel 545 may be: 1) a feature designed into the cover 432 of the component; 2) an independent feature mounted to the circuit board 401 and / or frame 431 of the component; or 3) some combination of 1) and 2) above.

[0067] In various embodiments, one or more conventional CDU return lines are also coupled to chamber 503 so that not all of the CDU returns through the chamber's flow enhancement structure(s).

[0068] Despite Figure 5a to Figure 5d The embodiments involve approaches in which flow enhancement structure 521 acts as an inlet for CDU return flow, but in other embodiments, flow enhancement structure 521 is coupled to a cooling fluid line from the CDU (having fluid channels similar to channel 545) and causes cooling fluid from the CDU to flow through the space between structure 521 and the radiator fins before the fluid is emitted from the flow enhancement structure to cool components in the bath other than those to which the radiator fins are connected.

[0069] Figures 6a to 6cAnother approach is contemplated in which the flow enhancement structure 621 is a bubble generating device that causes bubbles to flow (651) through the fins 612 of the heat sink 611. Here, as described in more detail below, the upward flow 651 of bubbles through the heat sink fins 612 results in increased buoyancy (upward) flow of the coolant liquid through the fins, which in turn increases the efficiency of heat transfer from the fins to the liquid.

[0070] Specifically, once created, the bubbles immediately begin to rise or otherwise flow at high speed through the space between the radiator fins 651 612 . Importantly, the gas pressure within the bubbles increases as the bubble diameter / size decreases. Therefore, small bubbles (e.g., with diameters in the range of 0.1 mm to 10 mm, inclusive) with high internal pressure are essentially "non-deformable" in the liquid. The non-deformable nature of the smaller bubbles causes them to exhibit effective "hardness", creating a wake behind the bubbles as they flow through the liquid (651). The wake creates a low-pressure area behind the bubbles, which is filled by the surrounding liquid 652. Therefore, as the bubbles rise upward, liquid is sucked in behind them, which in turn effectively increases the buoyancy fluid flow through the radiator fins 612.

[0071] Additionally, bubbles can create buoyancy forces near the fin surface that effectively thin the viscous (momentum) boundary layer and create a more uniform flow (increase flow velocity) across the fin area. When bubbles are located in the fin area, they effectively reduce the fluid density there and significantly increase buoyancy-induced flow. As mentioned above, bubbles will carry the cool fluid closer to the fin surface, which significantly reduces thermal resistance (increases heat transfer / efficiency). These dynamics can exist not only along the fin surface, but also at the root of the fin, which can significantly increase heat transfer.

[0072] Figure 6a A first embodiment is shown in which a bubble generating device 621 is placed below the heat sink 611 and / or its fins 612 when the corresponding electronic pluggable unit is installed in the immersion chamber. As the bubble generating device 621 generates bubbles below the heat sink 611 and / or the heat sink fins 612, the bubbles generated by the device 621 immediately rise through the fin area 612, thereby increasing the buoyancy flow through the fin area, as described above.

[0073] It is worth noting that the bubble generating device 621 can be an active device that requires power to operate. Therefore, there can be power wiring extending from the device 621 to the printed circuit board 601 to which the semiconductor chip package of the heat sink is mounted. In various embodiments, a first mechanical connector is mounted to the printed circuit board 601, and the wiring is a feature of the bubble generating device 621. The wiring includes a second mechanical connector that cooperates with the first mechanical connector. Alternatively, the opposite approach applies and the wiring is a feature of the printed circuit board 601.

[0074] The bubble generating device 621 may be mounted to any of the printed circuit board 601 (eg, with a standoff), the frame of the pluggable unit, the cover of the pluggable unit, or any combination of these.

[0075] In another or combined approach, e.g. Figure 6b As shown, the bubble generating device 621 faces the heat sink 611, rather than being located below the heat sink 611. In this approach, the bubble generating device 621 directly injects bubbles into most, if not all, of the heat sink fins 612. For example, the bubble generating device 621 can be a compressed air device that ejects a stream of bubbles laterally in the +x direction toward the face of the heat sink 611 in the space between the fins 612. Initially, this will cause a lateral flow of fluid past the heat sink fins before the bubbles begin to rise in the +z direction and generate the buoyancy flow described above.

[0076] exist Figure 6a and Figure 6b In either approach, the flow enhancement structure may also include one or more baffles or other flow guiding structures, which may be placed near the heat sink 611 to keep the bubbles in close proximity to the heat sink 611. Figure 6c Shows Figure 6a 612, but with a partial cover 655 placed over the upper half of the heat sink fins 612 (the cover may be integrated into and / or mounted to any of the cover, circuit board, or frame of the pluggable unit). The cover prevents air bubbles from escaping in the -x direction from the immediate vicinity of the upper half of the fins 612. Only half of the cover 655 is used to avoid creating excessive flow impedance for the source of the buoyant liquid flow.

[0077] Including as mentioned above Figure 6a , Figure 6b and Figure 6c The flow enhancement structure of the bubble generating device can be fully or partially integrated into the component cover 632, and / or include one or more separate components (e.g., the bubble generating device, (one or more) baffles, etc.) that are mounted to the cover, printed circuit board, frame, or any combination of two or more of these.

[0078] The design and operation of the bubble generating device 621 may vary from embodiment to embodiment. According to one approach, the bubble generating device is a frit device that generates bubbles by injecting air into a rough three-dimensional structure (eg, small carbon rocks like a typical aquarium filter).

[0079] According to another approach, the bubble generating device 621 is a chamber with holes for receiving compressed air. The compressed air flows out of the holes, forming a bubble stream from each hole. According to another approach, the hole is further defined as the hollow interior area of ​​a hollow needle extending from the chamber. The bubbles are emitted from the opening of the needle (similar to smoke coming out of multiple chimneys).

[0080] In either of these two approaches, the generation of bubbles can be promoted by lining the exposed hole surfaces with a coating that affects the ability of the coolant liquid to wet these surfaces. For example, if the bubbles are generated at least in part by the flow of coolant liquid into the hole or needle, the hole surfaces (including the exposed hole surfaces in the needle) can be coated with a material that promotes the coolant liquid to wet the hole surfaces. In contrast, if the bubbles are generated at least in part by preventing the coolant liquid from flowing into the hole or needle, the hole surfaces (including the exposed hole surfaces in the needle) can be coated with a material that inhibits the coolant liquid from wetting the hole surfaces.

[0081] In yet another bubble generation approach, the bubble generation device 621 is a peristaltic pump. For example, the bubble generation device 621 includes a hollow chamber covered by a porous diaphragm. A cam is continuously rotated in the chamber. The irregular shape of the cam causes air to be compressed against the inner surface of the diaphragm during a first portion of the cam's rotation. The compression of the air against the inner surface of the porous diaphragm causes bubbles to be discharged from the outer surface of the diaphragm into the surrounding liquid. During a second portion of the cam's rotation, new air is drawn into the inner surface of the diaphragm. The process is then repeated. In a further embodiment, the diaphragm is elastic. During the above-mentioned second rotation, the cam stretches the diaphragm outward to enhance the air impact intake suction against the inner surface of the diaphragm.

[0082] In another similar bubble generation approach, bubbles are generated by mechanical agitation (e.g., bending, vibration, etc.). Here, the agitation causes two phases: a first phase in which air is compressed within the chamber and expelled from holes within the chamber as bubbles; a second phase in which air is drawn into the chamber. For example, the different phases may correspond to opposite amplitudes of periodic mechanical motion (e.g., the chamber bends in a first direction in a first phase and in an opposite second direction in a second phase). The source of the mechanical agitation may be, for example, a piezoelectric device, an electromagnetic device (e.g., a speaker), etc.

[0083] In another approach, a multiphase (two-phase) flow of air and fluid is generated. The multiphase flow then passes through a structure that cuts the air in the flow into bubbles that are released into the coolant liquid. For example, a first fluid channel coupled to the coolant fluid and a second fluid channel coupled to an external air source are connected before a pump that draws fluid from the two fluid channels to generate the multiphase flow. As the multiphase flow flows through the pump, the pumping action of the pump "cuts" the air into bubbles. The fluid flows out of the pump and enters a chamber with holes. The bubbles pass through the holes into the liquid coolant.

[0084] In an alternative approach, a multiphase flow is generated by pumping only the coolant liquid through a pump. A venturi device is coupled downstream of the pump output. The venturi device is a fluid channel having a first portion with a wider flow cross-sectional area and a second portion with a narrower flow cross-sectional area. In the second portion, the velocity of the fluid increases and the pressure decreases. An air inlet is coupled to the second portion, which has a low pressure, and air is drawn into the second portion to generate a multiphase flow. The high velocity of the fluid in the second portion also cuts the air into small bubbles. The multiphase flow from the venturi device then enters a chamber having an orifice as described above.

[0085] In yet another approach, the bubble generating device includes a heat generator that nucleates the bubbles by heating the coolant liquid above the boiling point.

[0086] Since the bubble generating device 621 is an active component, its use can be adjusted as part of a larger power management scheme for the pluggable unit as its components and / or the device 621 are immersed in a larger immersion bath. For example, as long as the rate at which bubbles are generated can be adjusted (e.g., by compressing more or less air into the chamber, adjusting the rotational action of a cam or the pumping action of a pump, adjusting the amount of heat used to nucleate the bubbles), the bubble rate can be adjusted, for example, based on the power consumption and / or usage of (one or more) semiconductor chips within the chip package in which the bubble generating device 621 is positioned to generate bubbles against the fins of a heat sink of the package.

[0087] Thus, for example, at one extreme when the chip(s) are in sleep mode, there is no bubble generation activity; at another extreme when the chip(s) are in maximum power / usage mode, there is maximum bubble generation activity; and when the chip(s) are operating between these two extremes, there is less than maximum bubble generation activity. Thus, the above-described wiring of the bubble generation device may include, or be responsive to, a control software program executed, for example, on a processor on a circuit board of the pluggable unit or on some other computer or CPU system.

[0088] In the above teachings, it is noted that the heat sink fins are drawn as pin-like structures extending upward from the base of the heat sink. See, for example, Figure 3 The fins 312 and Figure 4a 412 in the heat sink. It is worth noting that other fin designs are possible, such as planar structures extending from the base of the heat sink. In this case (or similar cases), the heat sink should be oriented so that the fluid flow through the enhancement structure flows through the channels between the fins rather than being blocked by the planar walls of the fins. In addition, some heat sinks may not include fins, in which case the above teachings can still be utilized because the flow enhancement structure can be added to enhance the fluid flow through the exposed surface of the base of the heat sink.

[0089] Figure 7 A new, emerging paradigm for computing environments (e.g., data centers) is illustrated in which "infrastructure" tasks are offloaded from the traditional general-purpose "host" CPU (where application software programs are executed) to an infrastructure processing unit (IPU), a data processing unit (DPU), or a smart network interface card (SmartNIC), any / all of which are hereinafter referred to as an IPU.

[0090] Network-based computer services, such as cloud services and / or services provided by large enterprise data centers, typically execute application software programs for remote clients. Here, the application software programs typically perform specific (e.g., "business") end functions (e.g., customer service, procurement, supply chain management, email, etc.).

[0091] Remote clients call / use these applications through a temporary network session / connection established between the client and the application by the data center. A recent trend is to split at least some of the application's functionality into more fine-grained atomic functions ("microservices") that are called by client programs as needed. Microservices often strive to charge clients / customers based on their actual usage (function calls) of the microservice application.

[0092] However, in order to support the functionality of the network session and / or application, certain underlying computationally intensive and / or traffic intensive functions ("infrastructure" functions) are performed.

[0093] Examples of infrastructure functionality include encryption / decryption for secure network connections, compression / decompression for smaller footprint data storage and / or network communications, virtual networks between clients and applications and / or between applications, packet processing, ingress / egress queuing of network traffic between clients and applications and / or between applications, ingress or egress queuing of command / response traffic between applications and mass storage devices, error checking (including checksum calculations to ensure data integrity), distributed computing remote memory access capabilities, etc.

[0094] Traditionally, these infrastructure functions have been performed by CPU units that "sit below" their end-function applications. However, the intensity of infrastructure functions has begun to impact the ability of CPUs to execute their end-function applications in a timely manner relative to the expectations of clients, and / or in a power-efficient manner relative to the expectations of data center operators. Furthermore, CPUs are typically complex instruction set (CISC) processors that are better suited for executing processes for a variety of different application software programs than for more general and / or more focused infrastructure processes.

[0095] Therefore, if Figure 7 As shown, infrastructure functions are migrating to the Infrastructure Processing Unit (IPU). Figure 7 An exemplary data center environment 700 is depicted that integrates one or more IPUs 707_1 to offload infrastructure functions from a host CPU, as described above.

[0096] like Figure 7 As shown, an exemplary data center environment 700 includes a pool 701 of CPU units (e.g., multi-core processors) that execute final function application software programs 705 that are typically called by remote call clients. The data center 700 also includes a separate memory pool 702 and a large storage pool 703 to assist in executing the application program. The CPU pool 701, the memory pool 702, and the large storage pool 703 are coupled via one or more networks 704, respectively.

[0097] It is worth noting that each pool 701, 702, 703 has an IPU 707_1, 707_2, 707_3 on its front end or network side.

[0098] The IPU 707 performs pre-configured infrastructure functions on the inbound (request) packets it receives from the network 704 before passing the request to the final function of its corresponding pool (e.g., executing software in the case of the CPU pool 701, running memory in the case of the memory pool 702, and storing in the case of the mass storage pool 703). When the final function sends some communication to the network 704, the IPU 707 performs the pre-configured infrastructure functions on the outbound communication before sending it to the network 704.

[0099] According to an embodiment, one or more CPU pools 701, memory pools 702, mass storage pools 703, and networks 704 may exist within a single chassis, for example, as a conventional computing system (e.g., a server computer). In a decomposed computing system embodiment, one or more CPU pools 301, memory pools 702, and mass storage pools 703 are, for example, separate pluggable electronic units (e.g., pluggable CPU units, pluggable memory units (M), pluggable mass storage units (S)). Although Figure 7 Not shown, but similar to other pools, additional accelerator pools may also be coupled to network 704 via their own IPUs. An accelerator pool may include, for example, accelerator pluggable units including any combination of graphics processing units (GPUs), artificial intelligence inference semiconductor chips, artificial intelligence semiconductor chips, image processing accelerators, or other types of accelerators.

[0100] Notably, a conventional computing system and / or any of the above-described pluggable units may be mechanically configured to be submerged in an immersion bath, wherein the mechanical configuration is designed to increase fluid flow near a heat sink and / or heat sink fins, as described above.

[0101] In various embodiments, the software platform for executing the application 705 includes a virtual machine monitor (VMM) or a hypervisor that instantiates multiple virtual machines (VMs). Operating system (OS) instances are executed on VMs, respectively, and applications are executed on OS instances. Alternatively or in combination, container engines (e.g., Kubernetes container engines) are executed on OS instances, respectively. The container engine provides virtualized OS instances and containers that are executed on virtualized OS instances, respectively. Containers provide an independent execution environment for a set of applications, which may include applications for microservices.

[0102] Embodiments of the utility model may include various processes as described above. These processes may be embodied in program code (e.g., machine executable instructions). When the program code is processed, it causes a general or special processor to execute the process of the program code. Alternatively, these processes may be performed by specific / customized hardware components comprising hard-wired interconnect logic circuits (e.g., application specific integrated circuit (ASIC) logic circuits) or programmable logic circuits (e.g., field programmable gate array (FPGA) logic circuits, programmable logic device (PLD) logic circuits, etc.) for executing the process, or performed by any combination of program code and logic circuits.

[0103] The elements of the present invention may also be provided as machine-readable media for storing program codes. Machine-readable media may include, but are not limited to, floppy disks, optical disks, CD-ROMs and magneto-optical disks, flash memory, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, or other types of media / machine-readable media suitable for storing electronic instructions.

[0104] In the above description, the utility model has been described with reference to specific exemplary embodiments of the utility model. However, it is obvious that various modifications and changes can be made thereto without departing from the broader spirit and scope of the utility model as set forth in the appended claims. Therefore, the description and drawings should be regarded as illustrative rather than restrictive.

Claims

1. A device for cooling, characterized in that The device comprises: The flow enhancement structure is used to enhance the flow of the bathing liquid, especially the flow of the bathing liquid through the spaces between the fins of the heat sink and / or through the base of the heat sink.

2. The device according to claim 1, wherein: The flow enhancement structure comprises a suction conduit for returning the bathing liquid to a cooling distribution unit.

3. The device according to claim 1, wherein: The flow enhancement structure is for receiving a cooling fluid to be discharged into the bathing fluid after the bathing fluid flows through the flow enhancement structure.

4. The device according to claim 1, wherein: The flow enhancement structure comprises a bubble generating device.

5. The device according to claim 4, wherein: The bubble generating device is placed under the fins when an electronic circuit board having a semiconductor chip package coupled to the heat sink is immersed in the bathing liquid.

6. The device according to claim 4, wherein: When an electronic circuit board having a semiconductor chip package coupled to the heat sink is immersed in the bathing liquid, the bubble generating device is positioned to face the heat sink.

7. The device according to claim 4, wherein: The flow enhancement structure includes a guide structure for guiding the position where the bubbles generated by the bubble generating device flow within the bathing liquid.

8. The device according to claim 4, wherein: The bubble generating device is used to generate bubbles having a diameter in the range of 0.1 mm to 10 mm.

9. A device for cooling, characterized in that The device comprises: An electronic assembly, the electronic assembly comprising: i) Framework; ii) an electronic circuit board mounted to the frame; iii) a semiconductor chip package coupled to the electronic circuit board; iv) a heat sink including fins, the heat sink being coupled to the semiconductor chip package; v) a cover mounted to the frame and / or the electronic circuit board; vi) flow enhancing structure for enhancing the flow of bathing liquid, in particular the flow of the bathing liquid through the spaces between the fins and / or through the base of the heat sink when the component is immersed in the bathing liquid.

10. The device according to claim 9, wherein: The flow enhancement structure comprises a suction conduit for returning the bathing liquid to a cooling distribution unit or for receiving cooling fluid to be discharged into the bathing liquid after the bathing liquid has flowed through the flow enhancement structure.

11. The device according to claim 9, wherein: The flow enhancement structure comprises a bubble generating device.

12. The device according to claim 9, wherein: The flow enhancement structure is integral with the cover.

13. The device according to claim 9, wherein: The flow enhancement structure is mounted to the electronic circuit board and / or the frame.

14. The device according to claim 9, wherein: The flow enhancement structure includes an active device.

15. A data center, characterized in that The data center includes: network; a plurality of CPU pools coupled to the network; a plurality of memory pools coupled to the network; a plurality of storage pools coupled to the network; a chamber including a bathing fluid; An electronic unit located within the bathing liquid, the electronic unit being a component of one of the CPU pool, the memory pool, and the storage pool, the electronic unit comprising a flow enhancement structure for enhancing the flow of the bathing liquid, in particular the flow of the bathing liquid through the spaces between the fins of a heat sink and / or through the base of a heat sink, the heat sink being coupled to a semiconductor chip package of the electronic unit.

16. The data center according to claim 15, wherein: The flow enhancement structure comprises a suction conduit for returning the bathing liquid to a cooling distribution unit or for receiving cooling fluid to be discharged into the bathing liquid after the bathing liquid has flowed through the flow enhancement structure.

17. The data center according to claim 16, wherein: The recirculated fluid flows over the lower liquid-free surface to increase the flow rate through the spaces between the fins.

18. The data center according to claim 15, wherein: The flow enhancement structure includes an active device.

19. The data center according to claim 15, wherein: The flow enhancement structure comprises a bubble generating device.

20. The data center of claim 15, wherein: The flow enhancement structure is at least partially integrated with a cover of an assembly of the electronic unit and / or is at least partially mounted to an electronic circuit board and / or a frame of the electronic unit.

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