Hybrid Motherboard Cooling System for Air-Cooled Servers

Abstract

The motherboard assembly includes a motherboard, a first computing component attached to the motherboard, and a coolant container attached to the motherboard. An air-cooled heat sink is attached to the coolant container. The coolant container, the heat sink, and the motherboard form a hermetically sealed enclosure that contains the first computing component and is configured to hold a dielectric working fluid covering the first computing component. The heat sink is positioned to condense vapor formed from boiling of the dielectric working fluid and return the condensed dielectric working fluid to a pool of dielectric working fluid that includes the first computing component. Additionally, the motherboard assembly includes a second computing component attached to the motherboard and positioned outside the hermetically sealed enclosure.

Description

[Background technology]

[0001] Computing devices include heat-generating components that can generate significant amounts of heat during normal operation, such as central processing units (CPUs), graphic processing units (GPUs), tensor processing units (TPUs), memory devices, and other integrated circuits.

[0002] Computer cooling is the process of removing heat generated by heat-generating components within a computing device in order to keep the components within an acceptable operating temperature range. Cooling can be important because computer components are susceptible to temporary malfunction or permanent failure if they become overheated.

[0003] A data center is a physical facility used to house computing devices and related components. Data centers typically contain a large number of computing devices (e.g., servers) that may be stacked in racks arranged in rows. A colocation center is a type of data center where equipment, space, and network bandwidth are available for rental to customers.

[0004] Increasing power consumption of computing components has led to the introduction of novel cooling techniques, such as immersion cooling. Traditional immersion cooling methods involve immersing a computing device in a thermally conductive, electrically insulating dielectric fluid, sometimes referred to as a dielectric working fluid or thermal transfer fluid.

[0005] Broadly speaking, there are two different types of immersion cooling: single-phase immersion cooling and two-phase immersion cooling.

[0006] With a single-phase immersion cooling system, the dielectric working fluid never changes state and always maintains a liquid form. In some implementations, the dielectric working fluid can be actively circulated by pumping a dielectric coolant within, through, and around the computing device being cooled, which then transfers the heat absorbed by the coolant to a heat rejection device, such as a radiator, dry cooler, liquid-to-liquid heat exchanger, or cooling tower. Alternatively, the dielectric working fluid can be passively circulated by natural convection of the heated coolant to the heat rejection device.

[0007] In a two-phase immersion cooling system, the heat of vaporization and specific heat capacity properties of a dielectric working fluid are utilized for cooling. The dielectric working fluid generally has a relatively low boiling point so that heat absorbed by the dielectric working fluid surrounding the computing device boils off a portion of the dielectric working fluid, or vaporizes into a gas. The phase change of the dielectric working fluid carries heat away from the computing device. The vapor produced by the boiling of the dielectric working fluid rises above a fluid pool in contact with a condenser that is cooler than the boiling point of the dielectric working fluid. This causes the vapor to condense into a liquid and drop back down into the fluid pool.

[0008] The subject matter in this Background section is intended to provide an overview of the overall context of the subject matter disclosed herein. The subject matter discussed in this Background section should not be assumed to be prior art merely as a result of its mention in the Background section. Similarly, it should not be assumed that any problem mentioned in this Background section or related to the subject matter of this Background section was previously recognized in the prior art. Summary of the Invention

[0009] According to one aspect of the disclosure, a coolant vessel subassembly for a hybrid cooling system is disclosed. The coolant vessel subassembly comprises a coolant vessel comprising an upper portion and a lower portion. The coolant vessel subassembly further comprises a lower surface on the lower portion of the coolant vessel. The lower surface is configured for attachment to a motherboard to form an airtight sealed enclosure that contains a first computing component on the motherboard and does not contain a second computing component on the motherboard. The airtight sealed enclosure is configured to hold a dielectric working fluid in fluid communication with the first computing component. The coolant vessel subassembly further comprises an air-cooled heat sink and an upper surface on the upper portion of the coolant vessel. The upper surface is configured for attachment to the air-cooled heat sink such that the air-cooled heat sink is positioned to condense vapor formed from boiling of the dielectric working fluid and return the condensed dielectric working fluid to a pool of dielectric working fluid that contains the first computing component.

[0010] In some embodiments, the first computing component can generate a greater amount of heat flow than the second computing component.

[0011] In some embodiments, the first computing component may comprise a central processing unit (CPU) and the second computing component may comprise a memory device.

[0012] In some embodiments, the motherboard may include a two-phase cooling zone and an air cooling zone separate from the two-phase cooling zone. The first computing component and the coolant container may be attached to the two-phase cooling zone of the motherboard. The second computing component may be attached to the air cooling zone of the motherboard.

[0013] In some embodiments, the coolant container subassembly may further include a first groove in an upper portion of the coolant container and a first gasket that fits into the first groove and seals the upper portion of the coolant container to the heat sink, a second groove in a lower portion of the coolant container and a second gasket that fits into the second groove and seals the lower portion of the coolant container to the motherboard.

[0014] In some embodiments, the coolant vessel subassembly may further include an isolation valve having an open position and a closed position, the isolation valve being coupled to the coolant vessel such that when the isolation valve is in the open position, the dielectric working fluid can flow into or out of the interior of the coolant vessel, and when the isolation valve is in the closed position, the dielectric working fluid is prevented from flowing into or out of the interior of the coolant vessel.

[0015] In some embodiments, the coolant vessel subassembly may further include a pressure relief valve coupled to the coolant vessel.

[0016] In some embodiments, the coolant vessel subassembly may further include a temperature sensor positioned to detect a temperature change resulting from release of the dielectric working fluid from the pressure relief valve.

[0017] In some embodiments, the coolant vessel subassembly can further include a pressure sensor coupled to the coolant vessel and positioned to detect pressure within the hermetically sealed enclosure. The pressure sensor can be configured to be communicatively coupled to an auxiliary service processor on the motherboard.

[0018] In some embodiments, the first computing component may be a central processing unit (CPU), and the auxiliary service processor may be configured to reduce a clock frequency of the CPU in response to receiving an indication from the pressure sensor that the pressure within the hermetically sealed enclosure exceeds a threshold.

[0019] In some embodiments, the coolant can subassembly may further include a plate configured for attachment to the lower portion of the coolant can through the underside of the motherboard.

[0020] In some embodiments, the motherboard may include a plurality of mounting holes, and the coolant canister subassembly may further include a plurality of fasteners for attaching the coolant canister to the motherboard via the plurality of mounting holes.

[0021] According to another aspect of the disclosure, a motherboard assembly with a hybrid cooling system is disclosed. The motherboard assembly includes a motherboard with a two-phase cooling zone and an air cooling zone. The motherboard assembly includes a coolant vessel with an upper portion and a lower portion. The motherboard assembly includes a coolant vessel subassembly further including a lower surface on the lower portion of the coolant vessel. The lower surface is configured for attachment to the two-phase cooling zone of the motherboard to form an airtight sealed enclosure containing a first computing component in the two-phase cooling zone. The airtight sealed enclosure is configured to hold sufficient dielectric working fluid to immerse the first computing component in the dielectric working fluid. The motherboard assembly further includes an air-cooled heat sink and an upper surface on the upper portion of the coolant vessel. The upper surface is configured for attachment to the air-cooled heat sink such that the air-cooled heat sink is positioned to condense vapor formed from boiling of the dielectric working fluid and return the condensed dielectric working fluid to a pool of dielectric working fluid containing the first computing component. The motherboard assembly further includes an isolation valve coupled to the coolant vessel, the isolation valve being in fluid communication with an interior of the coolant vessel.

[0022] In some embodiments, the motherboard may further comprise a passive cooling zone. A two-phase cooling zone may be positioned between the passive cooling zone and the air cooling zone.

[0023] In some embodiments, at least one additional computing component may be attached to the two-phase cooling zone of the motherboard and may be positioned within the hermetically sealed enclosure when the underside on the lower portion of the coolant receptacle is attached to the two-phase cooling zone of the motherboard.

[0024] In some embodiments, the isolation valve may include an open position and a closed position. When the isolation valve is in the open position, the isolation valve may be coupled to the coolant vessel such that the dielectric working fluid can flow into or out of the interior of the coolant vessel. When the isolation valve is in the closed position, the dielectric working fluid may be prevented from flowing into or out of the interior of the coolant vessel.

[0025] In some embodiments, the motherboard assembly may further include a pressure relief valve coupled to the coolant reservoir and a temperature sensor positioned to detect a temperature change resulting from release of the dielectric working fluid from the pressure relief valve.

[0026] In some embodiments, the motherboard assembly may further include a pressure sensor coupled to the coolant vessel and positioned to detect pressure within the hermetically sealed enclosure. The pressure sensor may be configured to be communicatively coupled to an auxiliary service processor on the motherboard.

[0027] According to another aspect of the disclosure, a method for cooling a computing component in a server using a hybrid cooling system is disclosed. The method includes dividing a motherboard into a plurality of thermal zones including a two-phase cooling zone and an air-cooling zone. The method further includes mounting a first computing component in the two-phase cooling zone. The method further includes mounting a second computing component in the cooling zone. The method further includes mounting a lower portion of a coolant container in the two-phase cooling zone of the motherboard. The method further includes mounting a heat sink to an upper portion of the coolant container to form an enclosure with the first computing component. The method further includes hermetically sealing the enclosure. The method further includes adding a dielectric working fluid to the enclosure to form a pool of dielectric working fluid, the first computing component being immersed in the pool of dielectric working fluid. The method further includes operating a server including the first computing component and the second computing component.

[0028] In some embodiments, operation of the first computing component may cause the dielectric working fluid to boil. The method may further include positioning the heat sink to condense vapor formed from the boiling of the dielectric working fluid and return the condensed dielectric working fluid to the pool of dielectric working fluid.

[0029] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0030] Additional features and advantages are set forth in the following description. The features and advantages of the disclosure may be realized and obtained by means of the systems and methods particularly pointed out in the appended claims. Features of the disclosure may become more fully apparent from the following description and appended claims, or may be learned by practice of the disclosed subject matter as set forth hereinafter.

[0031] To explain how the above and other features of the present disclosure can be obtained, a more particular description will be provided by reference to certain embodiments of the present disclosure as illustrated in the accompanying drawings. For better understanding, like elements have been designated by like numerals throughout the various accompanying drawings. With the understanding that the drawings illustrate several exemplary embodiments, the embodiments will be described and explained with additional specificity and detail through the use of the following accompanying drawings. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 illustrates an example of a motherboard assembly including a hybrid cooling system according to the present disclosure. [Figure 2A] FIG. 2 illustrates an example of a motherboard divided into multiple thermal zones for use in a hybrid cooling system according to the present disclosure. [Figure 2B] FIG. 2 illustrates an example of a motherboard divided into multiple thermal zones for use in a hybrid cooling system according to the present disclosure. [Figure 3A] FIG. 1 illustrates an example of a coolant vessel that can be used in a hybrid cooling system according to the present disclosure. [Figure 3B] FIG. 1 illustrates an example of a coolant vessel that can be used in a hybrid cooling system according to the present disclosure. [Figure 4A] FIG. 1 illustrates an example of a coolant vessel subassembly that can be used in a hybrid cooling system according to the present disclosure. [Figure 4B]FIG. 1 illustrates an example of a coolant vessel subassembly that can be used in a hybrid cooling system according to the present disclosure. [Figure 5A] FIG. 2 illustrates an example of a motherboard assembly according to the present disclosure. [Figure 5B] FIG. 2 illustrates an example of a motherboard assembly according to the present disclosure. [Figure 6] FIG. 1 illustrates components within a hybrid cooling system that can be used to implement CPU power management techniques. [Figure 7] 7 illustrates an example of a method that can be performed by an auxiliary service processor in the system of FIG. 6. [Figure 8] FIG. 1 illustrates an example of a method for cooling computing components in a server using a hybrid cooling system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Several types of two-phase immersion cooling systems are currently under development by various hardware vendors and cloud providers. Existing solutions rely on specialized cooling systems, enclosures, or immersion tanks for the servers, and / or rely on a water supply. Therefore, existing two-phase cooling systems are very difficult to deploy in current generation data centers.

[0034] The present disclosure generally relates to a novel hybrid cooling system for computing devices such as servers used in data centers. The cooling system according to the present disclosure can support high performance computing components (e.g., high performance CPUs, GPUs) and can be deployed in standard air-cooled racks in existing data centers.

[0035] The cooling system according to the present disclosure can utilize a hermetically sealed coolant enclosure constructed around one or more heat generating components on the motherboard of a computing device. Thus, two-phase immersion cooling can be performed for the computing components located inside the enclosure. This allows for effective heat removal by boiling of a dielectric working fluid. The cooling system according to the present disclosure can also incorporate an air-cooled heat sink designed to condense the coolant vapor.

[0036] The cooling system according to the present disclosure may be a hybrid cooling system utilizing both immersion and air cooling. Computing components located inside the coolant enclosure may be cooled using two-phase immersion cooling. Other components on the motherboard may be cooled with air. The design of the coolant enclosure may be optimized for reduced use of dielectric working fluid and efficient air cooling of other motherboard components. The thermal design of the motherboard may be optimized for efficient use of air flow for condensation of coolant vapor on an air-cooled heat sink and efficient cooling of other motherboard components.

[0037] According to one embodiment of the present disclosure, the hybrid cooling system may be implemented as part of a motherboard assembly. A coolant container may be attached to the motherboard. An air-cooled heat sink may be attached to the coolant container to form a hermetically sealed chamber configured to hold a pool of dielectric working fluid. The coolant container may be positioned such that at least one heat-generating component (e.g., a CPU) on the motherboard is located within the hermetically sealed chamber and immersed in the pool of dielectric working fluid. The heat sink may be positioned to condense vapor formed from boiling of the dielectric working fluid and return the condensed dielectric working fluid to the pool of dielectric working fluid. Other heat-generating components (e.g., memory devices) may be positioned on the motherboard outside of the hermetically sealed chamber. A cooling system according to the present disclosure may thereby be a hybrid cooling system utilizing both immersion and air cooling methods.

[0038] As mentioned above, current server designs implementing immersion cooling are integrated with specialized water cooling systems, specialized enclosures, or immersion tanks and cannot be deployed in existing data centers without lengthy and expensive modifications to the data center engineering system. In contrast to conventional immersion cooling systems, the cooling system according to the present disclosure can be deployed in standard air-cooled racks in existing data centers. No additional infrastructure is required for such data center deployment, allowing for the utilization of standardized data center deployment footprints. Thus, the servers can be deployed, operated, maintained, and repaired without significant changes to the data center engineering systems or operating procedures. This allows for rapid and massive deployment of next generation servers with high performance components (e.g., CPUs with high thermal design power (TDP)) without upgrading the existing data center infrastructure.

[0039] Cooling systems according to the present disclosure may also include a pressure monitoring and pressure relief system for the hermetically sealed dual-phase coolant vessel, which allows for safe operation of components (e.g., a CPU) within the enclosure at maximum capacity of the cooling system.

[0040] 1 is a diagram illustrating an example of a motherboard assembly 100 including a hybrid cooling system according to the present disclosure. The motherboard assembly 100 includes a motherboard 102. Multiple computing components may be attached to the motherboard 102. In the embodiment illustrated in FIG. 1, the multiple computing components include a CPU 104 and multiple memory devices 106. Of course, other types of computing components may also be included on the motherboard 102.

[0041] The coolant receptacle 108 may be attached to the motherboard 102. Additionally, a heat sink 110 may be attached to the coolant receptacle 108. The motherboard 102, the coolant receptacle 108, and the heat sink 110 together may form a hermetically sealed enclosure 112 over one or more of the computing components on the motherboard 102. The heat sink 110 may provide a ceiling for the enclosure 112, the coolant receptacle 108 may provide sidewalls for the enclosure 112, and the motherboard 102 may provide a floor for the enclosure 112.

[0042] In the illustrated embodiment, the hermetically sealed enclosure 112 is formed over a single heat-producing component, namely, the CPU 104. In alternative embodiments, the hermetically sealed enclosure may be formed over multiple computing components. For example, the hermetically sealed enclosure may be formed over multiple CPUs, over a CPU and a GPU, over a CPU and a memory device, etc.

[0043] The hermetically sealed enclosure 112 formed by the motherboard 102, the coolant reservoir 108, and the heat sink 110 may be configured to hold a dielectric working fluid 114 that can be used for immersion cooling. The hermetically sealed enclosure 112 may be filled with a sufficient amount of the dielectric working fluid 114 such that the CPU 104 is immersed in a pool of the dielectric working fluid 114 at the bottom of the hermetically sealed enclosure 112. The CPU 104 generates heat during normal operation, which causes the dielectric working fluid 114 to boil. The vapor 116 formed from the boiling of the dielectric working fluid 114 rises to the upper portion of the hermetically sealed enclosure 112 where it condenses upon contact with the heat sink 110. The condensed dielectric working fluid 118 then descends back to the pool of the dielectric working fluid 114 at the bottom of the hermetically sealed enclosure 112.

[0044] Some of the computing components on the motherboard 102 are positioned outside the hermetically sealed enclosure 112. In particular, the memory devices 106 are positioned outside the hermetically sealed enclosure 112. Thereby, the cooling system shown in FIG. 1 may be a hybrid cooling system utilizing both immersion cooling and air cooling. In particular, the immersion cooling method can be used for the CPU 104, and the air cooling method can be used for the memory devices 106. The CPU 104 generates a larger amount of heat flow than the memory devices 106. Thus, the immersion cooling method can be used for the computing components that generate a larger amount of heat flow (i.e., the CPU 104), and the air cooling method can be used for the computing components that generate a smaller amount of heat flow (i.e., the memory devices 106).

[0045] Advantageously, the heat sink 110 can be simply cooled by air. Thus, the cooling system can be completely passive. Cooling can be achieved without the use of coolant or water circulating pumps, thereby improving system reliability and potentially reducing costs. The heat sink 110 can include a number of fins 120. The fins 120 increase the surface area of ​​the heat sink 110. The effectiveness of transferring heat from a metal surface to air can depend at least in part on the surface area. Thus, by increasing the surface area of ​​the heat sink 110, the fins 120 improve the ability of the heat sink 110 to transfer heat to the surrounding air. In the illustrated embodiment, the fins 120 extend upwardly away from the body of the heat sink 110. However, there are many other possible fin configurations that can be used on a heat sink in accordance with the present disclosure. Additionally, there are other types of structures (e.g., spikes, ribs, dimples) that can be added to the heat sink to increase its surface area.

[0046] In the illustrated embodiment, the fins 120 on the heat sink 110 are positioned on the outside of the hermetically sealed enclosure 112. In alternative embodiments, the interior portion of the heat sink may be configured with structures (e.g., spikes, ribs, dimples) that increase the surface area of ​​the heat sink. Such structures may be used to increase the surface area available for the vaporized working fluid to condense and possibly provide points for the condensed working fluid to gather and help drip into the working fluid pool at the bottom of the enclosure. The structures may also be used to help direct the condensed working fluid across the surface toward the center of the enclosure as opposed to dripping at the sides. For example, if the heat sink is configured with long ribs oriented toward the center of the enclosure, the condensed working fluid may flow to the end of the point and then drip into the working fluid pool below.

[0047] In some embodiments, the coolant vessel 108 and the heat sink 110 may be separate components. In other embodiments, the coolant vessel 108 and the heat sink 110 may be different parts of the same component.

[0048] As mentioned above, one aspect of the present disclosure relates to a thermal design of a motherboard that allows for efficient use of airflow for condensation of coolant vapor on an air-cooled heat sink and efficient cooling of other motherboard components. Figures 2A and 2B show an example of one possible design for a motherboard 202 according to the present disclosure.

[0049] 2A , in the illustrated embodiment, the motherboard 202 can be divided into multiple thermal zones. The multiple thermal zones can include a dual-phase cooling zone 222, multiple air cooling zones (including a first air cooling zone 224-1, a second air cooling zone 224-2, and a third air cooling zone 224-3), and multiple passive cooling zones (including a first passive cooling zone 228-1 and a second passive cooling zone 228-2).

[0050] The two-phase cooling zone 222 can be used for computing components that generate a large amount of heat flow and should be cooled using immersion cooling. Examples of such computing components include CPUs and GPUs, although other types of computing components can be included in the two-phase cooling zone 222 as well. The coolant receptacle 108 can be attached to the motherboard 202 in the two-phase cooling zone 222, thereby forming a hermetically sealed enclosure 112 over the computing components. The two-phase cooling zone 222 can include a number of mounting holes 230 that can be used to attach the coolant receptacle 108 to the motherboard 202.

[0051] Other zones on the motherboard 202 can be used for other types of computing components that do not generate as much heat flow as the components located in the two-phase cooling zone 222. For example, the first air-cooled zone 224-1 and the second air-cooled zone 224-2 can be used for memory devices (e.g., RAM modules), components with small heat sinks, and components without heat sinks. The third air-cooled zone 224-3 can be used for components with large heat sinks. The motherboard 202 can also include a zone 232 for fans that provide air circulation in the air-cooled zones 224-1, 224-2, 224-3. This zone 232 may be referred to herein as the air circulation zone 232. The passive cooling zones 228-1, 228-2 can be used for computing components that do not require active airflow.

[0052] Referring now to FIG. 2B, FIG. 2B illustrates multiple computing components mounted on a motherboard 202 according to the thermal zones illustrated in FIG. 2A.

[0053] In the illustrated example, the CPU 204 is mounted on the motherboard 202 in the two-phase cooling zone 222. A first plurality of memory devices 206-1, a first plurality of data storage components 234-1, a second plurality of data storage components 234-2, and a first plurality of CPU voltage regulator (VR) metal oxide semiconductor field effect transistors (MOSFETs) 240-1 are mounted on the motherboard 202 in the first air cooling zone 224-1. A second plurality of memory devices 206-2, a plurality of medium TDP chips without heat sinks (collectively designated by reference numeral 236), and a second plurality of CPU VR MOSFETs 240-2 are mounted on the motherboard 202 in the second air cooling zone 224-2. A high TDP chip 238 with a large heat sink is mounted on the motherboard 202 in the third air cooling zone 224-3. A plurality of fans 246 are shown in the air circulation zone 232.

[0054] A number of input / output (I / O) components, connectors, and low TDP chips (collectively designated by reference numeral 242) are mounted to the motherboard 202 in the first passively cooled zone 228-1. A number of CPU VR capacitors and inductors 244 are mounted to the motherboard 202 in the second passively cooled zone 228-2.

[0055] Beneficially, the design and layout of the motherboard 202 shown in FIGS. 2A and 2B enables the formation of a hermetically sealed enclosure 112 that can meet the signal integrity, power distribution, and thermal design requirements of a conventional server motherboard, while still enabling two-phase immersion cooling of several computing components on the motherboard 202.

[0056] Of course, the particular arrangement of computing components shown in Figures 2A and 2B is provided for illustrative purposes only and should not be construed as limiting the scope of the present disclosure. Motherboards can incorporate the principles of the hybrid cooling system disclosed herein while still utilizing different layouts of computing components.

[0057] 3A and 3B are diagrams illustrating an example of a coolant vessel 308 that can be used in a hybrid cooling system according to the present disclosure. The coolant vessel 308 is an example of the coolant vessel 108 described above in connection with FIG. 1. FIG 3A is a top perspective view of the coolant vessel 308. FIG 3B is a bottom perspective view of the coolant vessel 308.

[0058] Referring first to Figure 3A, the coolant vessel 308 may include an upper portion 348 and a lower portion 350. In the illustrated embodiment, both the upper portion 348 and the lower portion 350 of the coolant vessel 308 have a rectangular shape. In alternative embodiments, the upper and / or lower portions of the coolant vessel may have different shapes.

[0059] The top portion 348 of the coolant vessel 308 may include an opening. The size and shape of the opening may be suitable to accommodate the heat sink 110.

[0060] The upper portion 348 of the coolant vessel 308 may include an upper surface 349 configured for attachment to the heat sink 110. The upper surface 349 may include a groove 352-1, which may be referred to herein as an upper groove 352-1. The size and shape of the upper groove 352-1 may be designed to allow a gasket to fit within the upper groove 352-1. The gasket that fits within the upper groove 352-1 may be referred to herein as an upper gasket.

[0061] The top surface 349 on the top portion 348 of the coolant vessel 308 may also include a number of holes 354 that may receive fasteners. The number of holes 354 may be, for example, threaded holes or blind holes with threaded inserts. The fasteners may attach the top portion 348 of the coolant vessel 308 to the heat sink 110, and the top gasket may hermetically seal the top portion 348 of the coolant vessel 308 to the heat sink 110.

[0062] The coolant vessel 308 may include multiple openings. In particular, the top portion 348 of the coolant vessel 308 may include a first small opening 356-1 and a second small opening 356-2, as well as a large opening 358 positioned between the first small opening 356-1 and the second small opening 356-2. Similarly, the bottom portion 350 of the coolant vessel 308 may include a first large opening 360-1 and a second large opening 360-2. As will be described in more detail below, various openings of the coolant vessel 308 may be used to accommodate shutoff valves, pressure relief valves, and / or sensors. In some embodiments, these openings may have the form of threaded openings or push-fit openings.

[0063] 3B. In some embodiments, the vertical height 362 of the lower portion 350 of the coolant canister 308 may be approximately the same as the vertical height of one or more computing components located below the upper portion 348 of the coolant canister 308 when the coolant canister 308 is in place on the motherboard 102. For example, the vertical height 362 of the lower portion 350 of the coolant canister 308 may be approximately the same as the vertical height of a memory device 106 (e.g., a RAM module) on the motherboard 102 shown in FIG.

[0064] The bottom portion 350 of the coolant vessel 308 may also include an opening. The size and shape of the opening may be designed to fit around a component to be included in the hermetically sealed enclosure 112 configured to hold the dielectric working fluid 114. For example, if the coolant vessel 308 may be used in connection with the motherboard 102 shown in FIG. 1, the size and shape of the opening may be designed to fit around the CPU 104. In embodiments where the hermetically sealed enclosure is to include multiple components (e.g., a CPU and a GPU), the size and shape of the opening may be increased accordingly to accommodate the multiple components.

[0065] The lower portion 350 of the coolant receptacle 308 may include a lower surface 351 configured for attachment to the motherboard 102. The lower surface 351 may include a groove 352-2, which may be referred to herein as a lower groove 352-2. The size and shape of the lower groove 352-2 may be designed to allow a gasket to fit within the groove 352-2. The gasket that fits within the lower groove 352-2 may be referred to herein as a lower gasket.

[0066] The lower surface 351 on the lower portion 350 of the coolant canister 308 may also include a number of holes 364 that may receive fasteners. The number of holes 364 may be, for example, threaded holes or blind holes with threaded inserts. The fasteners may attach the lower portion 350 of the coolant canister 308 to the motherboard 102. In some embodiments, the fasteners may attach the lower portion 350 of the coolant canister 308 to a plate, and the motherboard 102 may be located between the lower portion 350 of the coolant canister 308 and the plate. The lower portion 350 of the coolant canister 308 may be adjacent to the upper surface of the motherboard 102. The lower gasket may fit into the lower groove 352-2 to hermetically seal the lower portion 350 of the coolant canister 308 to the upper surface of the motherboard 102. The plate may be adjacent to the lower surface of the motherboard 102. This type of configuration is described in more detail below.

[0067] In some embodiments, the interior 366 of the lower portion 350 of the coolant vessel 308 may be made from a plastic material that is compatible with the dielectric working fluid 114 .

[0068] The size and shape of the upper portion 348 of the coolant vessel 308 may be designed to maximize the surface area that the heat sink 110 can contact with the vaporized working fluid 114, thereby allowing condensation of the vaporized working fluid 114 to occur more easily, thereby increasing the effectiveness of the cooling process. The size and shape of the lower portion 350 of the coolant vessel 308 may be designed to accommodate the computing components on the motherboard 102 that are to be cooled by two-phase immersion cooling. In the embodiment shown in FIGS. 3A-3B, the above constraints result in the volume of the upper portion 348 of the coolant vessel 308 being larger than the volume of the lower portion 350 of the coolant vessel 308. However, this is not necessary, and in some embodiments, the volume of the lower portion of the coolant vessel may be equal to or larger than the volume of the upper portion of the coolant vessel.

[0069] As mentioned above, in alternative embodiments, the top and / or bottom portions of the coolant container may have different shapes. For example, in some alternative embodiments, the coolant container may have a rounded cross-section. One potential advantage of having a rounded cross-section would be ease of manufacture. In some other alternative embodiments, the coolant container may be shaped as a triangle with one edge facing toward the fan on the motherboard. One potential advantage of such a shape would be reduced airflow resistance.

[0070] Figures 4A and 4B show a coolant canister subassembly 470 that includes a coolant canister 408 along with other components that may be attached to or used with the coolant canister 408. The coolant canister 408 may be similar to the coolant canister 308 described above in connection with Figures 3A and 3B. Figure 4A is an expanded view of the coolant canister subassembly 470. Figure 4B is a perspective view of the coolant canister subassembly 470 shown in Figure 4A with the various components in place.

[0071] The coolant canister subassembly 470 may include an upper gasket 472-1 that hermetically seals the upper portion 448 of the coolant canister 408 to the heat sink 110. The coolant canister subassembly 470 may also include a lower gasket 472-2 that hermetically seals the lower portion 450 of the coolant canister 408 to the upper surface of the motherboard 102. The upper portion 448 of the coolant canister 408 may also include an upper groove 452-1 configured to receive the upper gasket 472-1. The upper portion 448 of the coolant canister 408 may also include a plurality of holes 454 that may receive fasteners for attaching the upper portion 448 of the coolant canister 408 to the heat sink 110.

[0072] The coolant vessel subassembly 470 may also include a number of isolation valves 474. A first isolation valve 474-1 and a second isolation valve 474-2 are shown in FIG. 4. The isolation valves 474 may be used to fill the coolant vessel 408 with the dielectric working fluid 114 and also to remove the dielectric working fluid 114 from the coolant vessel 408. The isolation valves 474 may also be used to remove residual vapor 116 from the dielectric working fluid 114 before repair and / or maintenance operations are performed.

[0073] The isolation valves 474 may be coupled to the lower portion 450 of the coolant vessel 408. For example, the isolation valves 474 may be inserted into openings in the lower portion 450 of the coolant vessel 408. In particular, the first isolation valve 474-1 may be inserted into the first opening 460-1 and the second isolation valve 474-2 may be inserted into the second opening 460-2. As mentioned above, the openings 460-1, 460-2 may be threaded or push-fit holes.

[0074] Each isolation valve 474 may be configured to have an open position and a closed position. When an isolation valve 474 is in an open position, the dielectric working fluid 114 may flow into or out of the interior of the coolant vessel 408. When an isolation valve 474 is in a closed position, the dielectric working fluid 114 may be prevented from flowing into or out of the interior of the coolant vessel 408.

[0075] To fill the coolant vessel 408 with the dielectric working fluid 114, a source of the dielectric working fluid 114 may be connected to one or more shut-off valves 474 via some type of distribution mechanism, which may include hoses or pipes. The shut-off valves 474 may then be placed in an open position. Various techniques (e.g., pressure differential, gravity) can be used to cause the dielectric working fluid 114 to flow from the source of the dielectric working fluid 114 into the coolant vessel 408.

[0076] A similar process may then be performed to remove the dielectric working fluid 114 from the coolant vessel 408. However, instead of connecting a source of the dielectric working fluid 114 to the isolation valve 474, a receptacle for holding the dielectric working fluid 114 to be removed from the coolant vessel 408 may instead be connected to the isolation valve 474.

[0077] The coolant vessel subassembly 470 may also include a pressure relief valve 476. The pressure relief valve 476 may be a type of safety valve used to control or limit the pressure inside the hermetically sealed enclosure 112 that contains the dielectric working fluid 114. The pressure relief valve 476 may be configured to open at a predetermined amount of pressure inside the hermetically sealed enclosure 112, thereby allowing some of the steam 116 within the hermetically sealed enclosure 112 to escape in order to reduce the pressure inside.

[0078] The pressure relief valve 476 may be coupled to the top portion 448 of the coolant vessel 408. For example, the pressure relief valve 476 may be inserted into the opening 458 in the top portion 448 of the coolant vessel 408. As described above, the opening 458 may be a threaded opening or a push-fit opening.

[0079] The coolant vessel subassembly 470 may further include a number of sensors. In the illustrated embodiment, the number of sensors includes a temperature sensor 478 and a number of pressure sensors (specifically, a first pressure sensor 480-1 and a second pressure sensor 480-2). The coolant vessel subassembly 470 may further include a connector mount 482 for connecting the temperature sensor 478 to the coolant vessel 408.

[0080] The temperature sensor 478 may be configured to detect the release of the dielectric working fluid 114 (either in vaporized or liquid form) from the pressure relief valve 476. The temperature of the dielectric working fluid 114 inside the hermetically sealed enclosure 112 may be significantly different (e.g., higher) than the ambient temperature outside the hermetically sealed enclosure 112. Thus, when the dielectric working fluid 114 is released from the pressure relief valve 476, this may cause the temperature surrounding the pressure relief valve 476 to change. The temperature sensor 478 may be configured to detect this temperature change. In some embodiments, the temperature sensor 478 may be communicatively coupled to an external system, such as an administrator system responsible for monitoring the servers in a data center. When the release of the dielectric working fluid 114 is detected, the external system may be notified so that appropriate corrective action can be taken.

[0081] The multiple pressure sensors 480-1, 480-2 may be inserted into small openings in the top portion 448 of the coolant vessel 408. In particular, a first pressure sensor 480-1 may be inserted into a first small opening 456-1 and a second pressure sensor 480-2 may be inserted into a second small opening 456-2.

[0082] The multiple pressure sensors 480-1, 480-2 may be configured to detect pressure inside the hermetically sealed enclosure 112. In embodiments in which one or more CPUs are located inside the hermetically sealed enclosure 112, the multiple pressure sensors 480-1, 480-2 may enable various types of CPU power management to occur. For example, overclocking, frequency boosting, and / or throttling may be performed based on the pressure detected by the multiple pressure sensors 480-1, 480-2.

[0083] In some embodiments, an auxiliary service processor (e.g., a baseboard management controller) may be attached to the motherboard 102, and the multiple pressure sensors 480-1, 480-2 may be communicatively coupled to the auxiliary service processor. The auxiliary service processor may be configured to perform CPU power management based on signals received from the multiple pressure sensors 480-1, 480-2. For example, in some embodiments, the auxiliary service processor may be configured such that in response to receiving an indication from at least one of the multiple pressure sensors 480-1, 480-2 that the pressure within the hermetically sealed enclosure 112 has exceeded a threshold value, a clock frequency of a CPU located within the hermetically sealed enclosure 112 is reduced.

[0084] Now referring to FIG. 4B, the upper gasket 472-1 is disposed in the upper groove 452-1 of the upper portion 448 of the coolant vessel 408. Although not visible in FIG. 4B, the lower gasket 472-2 is disposed in the lower groove of the lower portion 450 of the coolant vessel 408. The isolation valves 474-1, 474-2 are inserted into the openings 460-1, 460-2 of the lower portion 450 of the coolant vessel 408. The pressure relief valve 476 is inserted into the opening 458 of the upper portion 448 of the coolant vessel 408. The multiple pressure sensors 480-1, 480-2 are inserted into the small openings 456-1, 456-2 of the upper portion 448 of the coolant vessel 408. The temperature sensor 478 is connected to the coolant vessel 408 via a connector mount 482.

[0085] 5A and 5B are diagrams illustrating an example of a motherboard assembly 500 according to the present disclosure. FIG. 5A is an enlarged view of the motherboard assembly 500. FIG. 5B is a perspective view of the motherboard assembly 500 shown in FIG. 5A in an assembled state. Referring first to FIG. 5A, the motherboard assembly 500 includes a coolant container subassembly 570. The coolant container subassembly 570 may be similar to the coolant container subassembly 470 described above in connection with FIGS. 4A and 4B. The coolant container subassembly 570 includes a coolant container 508 having an upper portion 548 and a lower portion 550. A first shutoff valve 574-1 and a second shutoff valve 574-2 are coupled to the lower portion 550 of the coolant container 508. A temperature sensor 578 is coupled to the upper portion 548 of the coolant container 508 via a connector mount 582. One or more pressure sensors and a pressure relief valve may also be coupled to the coolant vessel 508, although these components are not visible in FIGS. 5A-5B.

[0086] The motherboard assembly 500 also includes a heat sink 510. The heat sink 510 may be similar to the heat sink 110 described above in connection with the motherboard assembly 100 shown in FIG. 1. A number of fasteners 584 may be used to attach the heat sink 510 to the top portion 548 of the coolant vessel 508. In the illustrated embodiment, the fasteners 584 may be inserted through holes 586 in the heat sink and into corresponding holes 554 in the top portion 548 of the coolant vessel 508.

[0087] The motherboard assembly 500 also includes a motherboard 502. The motherboard 502 includes a top surface 588 and a bottom surface. The bottom surface is opposite the top surface 588, not shown in FIGS. 5A-5B. A number of computing components are attached to the motherboard 502. A portion of the motherboard 502 may be reserved for components that generate a large amount of heat flow (e.g., a CPU) and should be cooled using an immersion cooling method. In the above description, this portion of the motherboard 502 is referred to as the two-phase cooling zone 222. A coolant reservoir 508 may be attached to the motherboard 502, such that the two-phase cooling zone 222 is covered by the coolant reservoir 508.

[0088] The motherboard assembly 500 also includes a plate 590. The plate 590 may enable the coolant canister subassembly 570 to be attached to the motherboard 502. Specifically, the plate 590 may include a number of holes 592 around its periphery. These holes 592 may align with corresponding holes 530 in the motherboard 502 and corresponding holes in the lower portion 550 of the coolant canister 508 (similar to holes 364 shown in FIG. 3B). A number of fasteners 594 may be used to attach the plate 590 to the coolant canister 508 through the motherboard 502. In particular, the lower portion 550 of the coolant canister 508 may be attached to the upper surface 588 of the motherboard 502, and the plate 590 may be attached to the lower portion 550 of the coolant canister 508 through the lower surface of the motherboard 502. When the motherboard assembly 500 is in an assembled state (as shown in FIG. 5B), the lower portion 550 of the coolant container 508 is positionable adjacent to the upper surface 588 of the motherboard 502, and the plate 590 is positionable adjacent to the lower surface of the motherboard 502.

[0089] Plate 590 may further include a groove 596. The size and shape of plate 590 may be designed to allow a gasket 598 to fit within groove 596. When plate 590 is attached to coolant canister 508, gasket 598 can seal plate 590 to the underside of motherboard 502. In addition to allowing coolant canister subassembly 570 to be attached to motherboard 502, plate 590 may also function to stiffen motherboard 502. This can help support motherboard 502 and reduce the chance of damage when motherboard 502 is being handled (e.g., for repair and / or maintenance).

[0090] 5B, the motherboard assembly 500 is shown in an assembled state. The coolant container 508 is shown having an upper portion 548 and a lower portion 550. The heat sink 510 is attached to the upper portion 548 of the coolant container 508. The lower portion 550 of the coolant container 508 is attached to the upper surface 588 of the motherboard 502. As mentioned above, a hybrid cooling system as disclosed herein may include one or more pressure sensors (e.g., pressure sensors 480-1, 480-2 shown in FIGS. 4A-4B) that may be configured to detect pressure inside the hermetically sealed enclosure. In embodiments where one or more CPUs are located inside the hermetically sealed enclosure, the multiple pressure sensors may enable various types of CPU power management to occur. FIG. 6 is a diagram illustrating components within a hybrid cooling system 600 that may be used to implement this feature.

[0091] 6 illustrates the logical relationships between the various components. The CPU 604 may be located in a hermetically sealed enclosure 612. The hermetically sealed enclosure 612 may be similar to the hermetically sealed enclosure 112 described above in connection with FIG. 1. The pressure sensor 680 may be configured to detect pressure inside the hermetically sealed enclosure 612. The auxiliary service processor 626 may be communicatively coupled to the pressure sensor 680 and further to the CPU 604. The auxiliary service processor 626 may be configured to perform one or more power management operations with respect to the CPU 604 based on signals received from the pressure sensor 680.

[0092] 7 illustrates an example of a method 700 executable by the auxiliary service processor 626 in the system 600 of FIG. 6. As indicated above, the auxiliary service processor 626 may be communicatively coupled to a pressure sensor 680. At 701, the auxiliary service processor 626 may receive a signal from the pressure sensor 680. The signal may be indicative of a pressure level inside the hermetically sealed enclosure 612. At 703, the auxiliary service processor 626 may determine, based on the signal received from the pressure sensor 680, whether the pressure inside the hermetically sealed enclosure 612 has exceeded a predefined threshold.

[0093] If the pressure inside the hermetically sealed enclosure 612 does not exceed the predefined threshold, method 700 may return to 701 and proceed as described above. However, if the pressure inside the hermetically sealed enclosure 612 does not exceed the predefined threshold, then at 705 the auxiliary service processor 626 may reduce the clock frequency of the CPU 604. This may involve sending one or more signals (e.g., commands) to the CPU 604.

[0094] In some embodiments, the method 700 shown in FIG. 7 enables overclocking to be performed with respect to the CPU 604. Broadly speaking, overclocking is the technique of increasing the clock speed of a computing component to exceed the clock speed certified by the manufacturer. In other words, overclocking increases the operating speed of a given component. Typically, overclocking is used to increase the performance of a major chip or subsystem, such as a main processor (e.g., CPU 604) or a graphics controller.

[0095] Overclocking increases power consumption. When a particular component is overclocked, higher currents and voltages are applied to the component, thereby increasing power consumption. With reference to the system 600 shown in FIG. 6, if overclocking is performed on the CPU 604, this may increase the temperature (and therefore pressure) within the hermetically sealed enclosure 612. If the temperature and pressure are increased too much, the CPU 604 may be damaged. By using a pressure sensor 680 to monitor the pressure inside the hermetically sealed enclosure 612 and taking corrective action (e.g., reducing the clock frequency of the CPU 604) if the pressure exceeds a predefined threshold, overclocking can be performed in a safe manner.

[0096] 8 illustrates an example method 800 for cooling computing components in a server using a hybrid cooling system. The method 800 will be described with reference to the components listed above.

[0097] At 801, the motherboard 102 may be divided into multiple thermal zones, including the dual-phase cooling zone 222 and one or more air-cooled zones 224-1, 224-2, 224-3. The motherboard 102 may include other thermal zones as well, such as one or more passive cooling zones 228-1, 228-2.

[0098] At 803, a first computing component (e.g., CPU 104) may be installed in the two-phase cooling zone 222. At 805, a second computing component (e.g., memory device 106) may be installed in the air cooling zone 224-1.

[0099] At 807, a lower portion 350 of the coolant canister 308 may be attached to the two-phase cooling zone 222 of the motherboard 102. At 809, a heat sink 110 may be attached to an upper portion 348 of the coolant canister 308 to form an enclosure 112 that includes the first computing component. At 811, the enclosure 112 may be hermetically sealed.

[0100] At 813, the dielectric working fluid 114 may be added to the enclosure 112. A sufficient amount of the dielectric working fluid 114 can be added such that a first computing component (e.g., the CPU 104) can be immersed in a pool of the dielectric working fluid 114.

[0101] At 815, the server (including the first computing component and the second computing component) may be operated. Operation of the server generates heat in the first computing component inside the hermetically sealed enclosure 112, which may cause the dielectric working fluid 114 to boil. The heat sink 110 may be positioned such that it condenses the vapor 116 formed from the boiling of the dielectric working fluid 114 and returns the condensed dielectric working fluid 118 to the pool of dielectric working fluid 114.

[0102] The techniques disclosed herein provide many advantages for computer cooling compared to current approaches, some of which are described below. Those skilled in the art may recognize additional benefits and advantages of the disclosed techniques beyond those specifically described herein.

[0103] As discussed above, one aspect of the present disclosure is directed to a fully enclosed air-cooled design of a dual-phase cooling enclosure, which offers several benefits compared to current approaches. For example, the compact cooling system design allows for high density compute deployments and allows for higher TDP CPUs to be used compared to traditional air-cooled systems. Additionally, the self-enclosed cooling system design allows the servers to be packaged as standalone deployable units. Furthermore, the servers can be deployed in standard air-cooled racks in existing data centers. No additional infrastructure is required for data center deployment, allowing for the utilization of a standardized data center deployment footprint. To the extent that the new immersion cooling system is incorporated into future data centers, the server fleet can be upgraded to the proposed new cooling system over time without the high up-front costs of infrastructure upgrades.

[0104] The hermetic design of the two-phase cooling enclosure also provides several benefits over current approaches. For example, the hermetic design of the two-phase cooling enclosure allows for a completely passive operation of the cooling system to be achieved without the use of coolant or water circulation pumps, thereby improving the reliability of the overall system. In addition, coolant loss can be eliminated during normal operation of the server. Also, the server can be serviced independently without exposure of personnel and the environment to coolant vapor or liquid. Furthermore, the amount of two-phase coolant usage per server can be significantly reduced. Furthermore, external server connections (I / O ports, power supplies, etc.) are not exposed to the coolant liquid. The overall design of the cooling system also provides several benefits over current approaches. For example, the cooling system can be built using off-the-shelf industry components. Existing designs of server motherboards can be adapted with minimal modifications. Existing designs of air-cooled servers can be used for packaging with minimal modifications.

[0105] As an example, the term "dielectric working fluid" (or simply "working fluid") may refer to any non-conductive fluid in which a computing device may be immersed for the purpose of cooling the computing device. Some examples of dielectric working fluids that may be used include synthetic fluids, fluorocarbon-derived fluids, mineral oil, and deionized water. The dielectric working fluid may have a relatively low boiling point (e.g., 40-50°C) such that heat generated by the computing device will normally boil the dielectric working fluid.

[0106] As an example, the term "auxiliary service processor" may refer to a specialized microcontroller in a computing device that is separate from the general-purpose processor. One example of an auxiliary service processor is a baseboard management controller (BMC). It may be useful for an auxiliary service processor to be included in a server that is part of a cloud computing system because a system administrator can perform various tasks remotely. For example, a system administrator can use a management system (e.g., a fabric controller) to remotely communicate with the auxiliary service processor to take corrective action, such as resetting or power cycling the server.

[0107] As an example, two structures may be "fluidly connected" to one another if a path exists by which a fluid can flow between the structures. In this context, the term "fluid" may generally refer to any substance that tends to assume the shape of its container and may include a liquid or a gas.

[0108] As an example, the term "heat flow" may refer to the rate of thermal energy flow per unit surface area of ​​a heat transfer surface.

[0109] As an example, the term "thermal design power" or "TDP" may refer to the maximum amount of heat generated by a computing component that a cooling system is designed to dissipate under a given workload. In some contexts, TDP may refer to the maximum amount of heat generated by a component that a cooling system can dissipate under real-world conditions.

[0110] As an example, the phrase "communicatively coupled" may refer to coupling components such that they can communicate with one another, for example, through wired, wireless, or other communications media. The phrase "communicatively coupled" may include direct communications couplings as well as indirect or "mediated" communications couplings. For example, component A may be directly communicatively coupled to component B by at least one communications path, or component A may be indirectly communicatively coupled to component B by at least a first communications path directly coupling component A to component C and at least a second communications path directly coupling component C to component B. In this case, component C is said to mediate the communications coupling between component A and component B.

[0111] The word "determining" (and grammatical variations thereof) may encompass a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, examining, looking up (e.g., looking up in a table, database, or another data structure), verifying, and the like. Also, the word "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also, the word "determining" may include resolving, selecting, choosing, establishing, and the like.

[0112] The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. In addition, it should be understood that references to "one embodiment" or "embodiments" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. For example, any element or feature described herein in connection with an embodiment may be combined with an element or feature of any other embodiment described herein, where compatible.

[0113] The phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" describes both "based only on" and "based at least on."

[0114] The steps, operations, and / or actions described herein may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps, operations, and / or actions is required for proper functional performance of the methods being described, the order and / or use of specific steps, operations, and / or actions may be modified without departing from the scope of the claims.

[0115] In the above description, reference numbers may be used in conjunction with various terms. When a term is used in conjunction with a reference number, this may be intended to refer to a specific element shown in one or more of the figures. When a term is used without a reference number, this may be intended to refer to the term generally, without limitation to any particular figures.

[0116] The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments should be considered as illustrative and not limiting. The scope of the present disclosure is therefore defined by the appended claims, rather than the above description. All changes within the meaning and range of equivalence of the claims are intended to be embraced within their scope.

Claims

1. 1. A coolant vessel subassembly for a hybrid cooling system, comprising: a coolant vessel having an upper portion and a lower portion; a lower surface of the lower portion of the coolant vessel, the lower surface configured for attachment to the motherboard to form a hermetically sealed enclosure that contains a first computing component on the motherboard and does not contain a second computing component on the motherboard, the hermetically sealed enclosure configured to hold a dielectric working fluid in fluid communication with the first computing component; An air-cooled heat sink; an upper surface of the upper portion of the coolant vessel, the upper surface being configured for attachment to the air-cooled heat sink such that the air-cooled heat sink is positioned to condense vapor formed from boiling of the dielectric working fluid and return the condensed dielectric working fluid to a pool of the dielectric working fluid that contains the first computing component; A coolant vessel subassembly comprising:

2. 2. The coolant vessel subassembly of claim 1, wherein an upper cross-sectional area of ​​the coolant vessel has a surface area greater than a lower cross-sectional area of ​​the coolant vessel.

3. 3. The coolant container subassembly of claim 1 or 2, wherein the first computing component generates a greater amount of heat flow than the second computing component.

4. 3. A coolant container subassembly according to claim 1 or 2, comprising: the first computing component includes a central processing unit (CPU); the second computing component includes a memory device; Coolant vessel subassembly.

5. 3. The coolant vessel subassembly of claim 1 or 2, wherein the motherboard includes a two-phase cooling zone and an air cooling zone separate from the two-phase cooling zone; the first computing component and the coolant container are attached to the two-phase cooling zone of the motherboard; the second computing component is mounted in the air cooling zone of the motherboard; Coolant vessel subassembly.

6. 3. A coolant container subassembly according to claim 1 or 2, comprising: a first groove in the upper portion of the coolant vessel; a first gasket that fits within the first groove and seals the top portion of the coolant vessel to the air-cooled heat sink; a second groove in the lower portion of the coolant vessel; a second gasket that fits within the second groove and seals the lower portion of the coolant vessel to the motherboard; and The coolant vessel subassembly further comprises:

7. 3. The coolant vessel subassembly of claim 1 or 2, further comprising an isolation valve including an open position and a closed position, the isolation valve comprising: when the isolation valve is in the open position, the dielectric working fluid can flow into or out of the interior of the coolant vessel; When the isolation valve is in the closed position, the dielectric working fluid is prevented from flowing into or out of the interior of the coolant vessel. a coolant container subassembly coupled to said coolant container.

8. 3. The coolant vessel subassembly of claim 1 or 2, further comprising a pressure relief valve coupled to the coolant vessel.

9. 9. The coolant vessel subassembly of claim 8, further comprising a temperature sensor positioned to detect a temperature change resulting from release of the dielectric working fluid from the pressure relief valve.

10. 3. A coolant container subassembly according to claim 1 or 2, comprising: the coolant vessel subassembly further comprising a pressure sensor coupled to the coolant vessel and positioned to detect pressure within the hermetically sealed enclosure; the pressure sensor is configured to be communicatively coupled to an auxiliary service processor on the motherboard; Coolant vessel subassembly.

11. 11. The coolant container subassembly of claim 10, the first computing component is a central processing unit (CPU); the auxiliary service processor is configured to reduce a clock frequency of the CPU in response to receiving an indication from the pressure sensor that the pressure within the hermetically sealed enclosure has exceeded a threshold. Coolant vessel subassembly.

12. 3. The coolant canister subassembly of claim 1 or 2, further comprising a plate configured for attachment to the lower portion of the coolant canister through a lower surface of the motherboard.

13. 3. A coolant container subassembly according to claim 1 or 2, comprising: the motherboard has a plurality of mounting holes; the coolant container subassembly further comprising a plurality of fasteners for attaching the coolant container to the motherboard through the plurality of mounting holes. Coolant vessel subassembly.

14. 1. A motherboard assembly with a hybrid cooling system, comprising: a motherboard having a dual-phase cooling zone and an air cooling zone; a coolant vessel having an upper portion and a lower portion; a lower surface of the lower portion of the coolant vessel, the lower surface configured for attachment to the two-phase cooling zone of the motherboard to form a hermetically sealed enclosure containing a first computing component in the two-phase cooling zone, the hermetically sealed enclosure configured to retain sufficient dielectric working fluid to immerse the first computing component in the dielectric working fluid; An air-cooled heat sink; an upper surface of the upper portion of the coolant vessel, the upper surface configured for attachment to an air-cooled heat sink such that the air-cooled heat sink is positioned to condense vapor formed from boiling of the dielectric working fluid and return the condensed dielectric working fluid to a pool of the dielectric working fluid that contains the first computing component; and an isolation valve coupled to the coolant vessel, the isolation valve being in fluid communication with an interior of the coolant vessel; A motherboard assembly comprising:

15. 15. The motherboard assembly of claim 14, wherein an upper cross-sectional area of ​​the coolant vessel has a greater surface area than a lower cross-sectional area of ​​the coolant vessel.

16. 16. A motherboard assembly according to claim 14 or 15, the motherboard further comprises a passive cooling zone; the two-phase cooling zone being positioned between the passive cooling zone and the air cooling zone. Motherboard assembly.

17. 16. A motherboard assembly as described in claim 14 or 15, wherein at least one additional computing component is attached to the two-phase cooling zone of the motherboard and positioned within the hermetically sealed enclosure when the underside of the lower portion of the coolant container is attached to the two-phase cooling zone of the motherboard.

18. 16. A motherboard assembly as claimed in claim 14 or 15, wherein the isolation valve includes an open position and a closed position, the isolation valve comprising: when the isolation valve is in the open position, the dielectric working fluid can flow into or out of the interior of the coolant vessel; When the isolation valve is in the closed position, the dielectric working fluid is prevented from flowing into or out of the interior of the coolant vessel. a motherboard assembly coupled to said coolant container.

19. 16. A motherboard assembly according to claim 14 or 15, a pressure relief valve coupled to the coolant vessel; a temperature sensor positioned to detect a temperature change resulting from the release of the dielectric working fluid from the pressure relief valve; a motherboard assembly further comprising:

20. 16. A motherboard assembly according to claim 14 or 15, the motherboard assembly further comprising a pressure sensor coupled to the coolant vessel and positioned to sense pressure within the hermetically sealed enclosure; the pressure sensor is configured to be communicatively coupled to an auxiliary service processor on the motherboard; Motherboard assembly.

21. 1. A method of using a hybrid cooling system for cooling computing components in a server, comprising: Dividing the motherboard into a number of thermal zones, including a dual-phase cooling zone and an air cooling zone; installing a first computing component in the dual-phase cooling zone; installing a second computing component in the air cooling zone; attaching a lower portion of a coolant can to the two-phase cooling zone of the motherboard; attaching a heat sink to an upper portion of the coolant container to form an enclosure containing the first computing component; hermetically sealing the enclosure; adding a dielectric working fluid to the enclosure to form a pool of the dielectric working fluid, the first computing component being immersed in the pool of the dielectric working fluid; operating the server including the first computing component and the second computing component, the server including operating without a pump for the dielectric working fluid; The method includes:

22. 22. The method of claim 21 , wherein operation of the first computing component boils the dielectric working fluid, the method further comprising positioning the heat sink to condense vapor formed from the boiling of the dielectric working fluid and return condensed dielectric working fluid to the pool of dielectric working fluid.

23. 3. The coolant can subassembly of claim 1 or 2, wherein the top portion extends over a portion of the motherboard.

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