Ball grid array vapor tube for two-phase immersion cooling systems

Abstract

A conduit provides a pressure-relief mechanism for computing system including a cavity between a substrate and a computing device such as an integrated circuit. The computing device is attached to the substrate through a ball grid array and sealed around the edges of the computing device using a sealant. The conduit fluidically couples the cavity to an environment surrounding the computing device. When the computing system is immersed in immersion cooling liquid, immersion cooling vapor generated by the operation of the computing device within the cavity can escape through the conduit and prevent the cavity from over-pressurizing.

Description

BALL GRID ARRAY VAPOR TUBE FOR TWO-PHASE IMMERSION COOLINGSYSTEMSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This Application claims the benefit of provisional U.S. Application No. 63 / 568,230, filed on March 21, 2024, and entitled “BALL GRID ARRAY VAPOR TUBE FOR TWO-PHASE IMMERSION COOLING SYSTEMS,” which is hereby incorporated by reference in its entirety.

[0002] In cases where the present application conflicts with a document incorporated by reference, the present application controls.BACKGROUND

[0003] As feature sizes and transistor sizes have decreased for computing hardware such as integrated circuits (ICs) including chips and semiconductor dies, the amount of heat generated by a single chip, such as a microprocessor, has increased. Computing hardware that has traditionally been air cooled has evolved to levels of power consumption requiring more heat dissipation than can be provided by air alone. In some cases, immersion cooling of ICs in a tank containing a coolant fluid is employed to maintain ICs at appropriate operating temperatures.

[0004] One type of immersion cooling is two-phase immersion cooling, in which heat from a semiconductor die is high enough to boil the coolant fluid. The boiling creates a coolant fluid vapor in the tank, which is condensed by cooling coils back to liquid form. Heat from the semiconductor dies can then be sunk into the liquid-to-gas and gas-to-liquid phase transitions of the coolant fluid with the result that the semiconductor dies are kept at an acceptable temperature.

[0005] The flow, movement, and circulation of immersion cooling vapor plays a significant role in a cooling system efficiency. In certain instances, immersion cooling vapor generated by a first computing device may increase a pressure in a cavity formed between the computing device and a substrate to which it is mounted. If the pressure is not managed, the computing device may be damaged or destroyed.SUMMARY

[0006] A vapor tube conduit enables dynamic regulation of vapor pressure in a four-sided edge bonded ball grid array (BGA) application-specific integrated circuit (ASIC). The tube opening in the liquid may open below the BGA (e.g., about 10 mm below). The conduit may be solderattached to a printed circuit board (PCB) substrate or on a corner of the ASIC substrate itself. A polymer tube can also be epoxied to the PCB to have a similar function as a metal tube. A vapor tube can also be designed into the PCB as a hollow trace within the layers of the PCB to a predesignated opening in the PCB that is below the liquid level of the ASIC.

[0007] In some aspects, the techniques described herein relate to a computing system configured for immersion in a coolant liquid of a two-phase immersion cooling system, the computing system including: a substrate; a device mounted to the substrate, the device including an integrated circuit; a sealant directly coupled to the substrate and the device and disposed along at least a portion of each edge of the device such that the sealant, the device, and the substrate together form a cavity configured to trap one or more bubbles of a gas when the computing system is immersed in the coolant liquid; and a conduit configured to provide a fluidic connection between the cavity and an environment surrounding the computing system.

[0008] In some aspects, the techniques described herein relate to a computing system, wherein the conduit is disposed in contact with at least one of the substrate, the device, or the sealant.

[0009] In some aspects, the techniques described herein relate to a computing system, wherein the conduit includes an inner diameter of equal to or less than 1 mm.

[0010] In some aspects, the techniques described herein relate to a computing system, wherein the conduit includes a length equal to or greater than 10 mm.

[0011] In some aspects, the techniques described herein relate to a method for vapor management, the method including: generating, by a device attached to a substrate and immersed in immersion cooling liquid, waste heat; vaporizing, by the waste heat, the immersion cooling liquid to create immersion cooling vapor in a cavity formed by the substrate, the device, and a sealant directly coupled to the substrate and the device; and directing the immersion cooling vapor out of the cavity through a conduit, the conduit fluidically coupling the cavity to an environment surrounding the device.

[0012] In some aspects, the techniques described herein relate to a method, wherein the conduit is disposed in contact with at least one of the substrate, the device, or the sealant.

[0013] In some aspects, the techniques described herein relate to a method, wherein the conduit includes an inner diameter of equal to or less than 1 mm.

[0014] In some aspects, the techniques described herein relate to a method, wherein the conduit includes a length equal to or greater than 10 mm.

[0015] All combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are part of the inventive subject matter disclosed herein. The terminology used herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The skilled artisan will understand that the drawings primarily are for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and / or structurally similar elements).

[0017] FIGS. 1A-1C show an example computing system with an edge sealed electronic device according to the inventive concepts disclosed herein.

[0018] FIGS. 2A-F illustrate several views of a computing system including a conduit for allowing trapped immersion cooling vapor to escape from cavity.

[0019] FIGS. 3 A-B illustrate aspects of conduit including longitudinal axis, inner diameter, and outer diameter.

[0020] FIG. 4 depicts aspects of an immersion cooling system for dissipating heat from one or more heat-generating components such as semiconductor die packages via immersion cooling.DETAILED DESCRIPTION

[0021] FIGS. 1A-1C show an example computing system 100 with an edge sealed electronic device 110. As shown, the device 110 is mounted to a substrate 120 via a ball grid array (BGA) 112. It should be appreciated that the computing system is a non-limiting example and that the edge sealed devices disclosed herein may be mounted to a substrate in other ways, such as with a pin grid array (PGA) or a land grid array (LGA). The device 110 may include an integrated circuit. For example, the device 110 may be a computer processor unit (CPU), a graphics processor unit (GPU), a data processing unit (DPU), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), memory (e.g., rapid access memory), and / or the like. The substrate 120 may be a printed circuit board (PCB) or a printed circuit board assembly(PCBA), e.g., a PCB with other electronic components mounted thereto.

[0022] As shown in FIG. 1 A, the computing system 100 includes a sealant 130 disposed on the edges 111-1, 111-2, 111-3, and 111-4 of the device 110. The sealant 130 forms an edge bond that seals gaps formed between the device 110 and the substrate 120, thus preventing fluid from passing through the gaps between the device 110 and the substrate 120 where the sealant 130 is present. For example, FIG. 1C shows the sealant 130 may fill the gaps between the device 110 and the substrate 120 along the edges 111-2 and 111-3.

[0023] For the example computing system 100, FIG. 1 A shows the sealant 130 may cover the entirety of the edges 111-1, 111-2, 111-3, and 111-4. In some implementations, the computing system 100 may be oriented such that the edges 111-2 and 111-3 are oriented vertically and the edges 111-1 and 111-4 are oriented horizontally with the edge 111-1 disposed above the edge 111-4, as shown in FIG. 1 A (the vector g represents the direction of gravity). Thus, the edges 111-1, 111-2, 111-3, and 111-4 may correspond to a top edge, left-side edge (or, alternatively, a right-side edge), a right-side edge (or, alternatively, a left-side edge), and a bottom edge, respectively.

[0024] It should also be appreciated that the orientation of the computing system 100 and / or the device 110 described above (e.g., with the edges 111-1 and 111-4 oriented horizontally and the edges 111-2 and 111-3 oriented vertically) is a non-limiting example.

[0025] It should also be appreciated that the sealant 130 may be applied to devices of various shapes. For example, the device 110 may generally be substantially flat and have a shape that includes, but is not limited to, a square, a rectangle, a circle, a polygon, and any combinations of the foregoing. Additionally, the device 110 may have beveled or rounded comers.

[0026] The sealant 130 may be formed from a compound that hardens (e.g., a UV epoxy, a composite, or a eutectic metal), as described above in Section 1.1. In one non-limiting example, the sealant 130 may be formed of 3M Scotch-Weld DP420 (see Appendix B). In another nonlimiting example, the sealant 130 may be formed of Zymet X2821 (see Appendix C). In some implementations, the sealant 130 may have a resistivity, dielectric constant, dielectric strength, and coefficients of thermal expansion within 25%, preferably within 5% to 10%, of one or both of 3M Scotch-Weld DP420 and / or Zymet X2821. The sealant 130 may generally be applied after the device 110 is mounted to the substrate 120. After application, the sealant 130 may be cured, for example, by heating the sealant 130 to an elevated temperature, exposing the sealant 130 to radiation (e.g., ultraviolet radiation), and / or waiting for a predetermined period of time for the sealant 130 to harden.

[0027] The sealant 130 may substantially cover the edges 111-1, 111-2, 111-3, and 111-4 such that the device 110, the substrate 120, and the sealant 130 together form a cavity 116 sufficient to trap one or more bubbles of a gas (e.g., coolant vapor, air). These bubbles of gas may be formed during operation of the device 110, for example, due to the waste heat produced by the device 110 while performing computations.

[0028] FIGS. IB and 1C illustrate side perspectives of computing system 100. FIG. IB shows sealant 130 along an edge of device 110, sealing (in combination with the other edges 111-1 through 111-4) the volume beneath device 110.

[0029] Absent a suitable mechanism for relieving pressure, the bubbles of gas may increase a pressure of cavity 116 beyond an ability of sealant 130 to hold the device 110 in contact with substrate 120. This pressure may cause one or more solder connections of BGA 112 and / or sealant 130 to fracture, disconnect, or otherwise fail, which may damage or destroy computing system 100 including solder ball connections of BGA 112. Thus, the inventors have recognized and appreciated the need for managing an increase in pressure caused by creation of vapor during device operation.

[0030] Further examples of arrangements of computing devices such as integrated circuits mounted to substrates, ball grid arrays, and similar components and sealed with sealants may be found in U.S. Provisional Patent Application 63 / 503,405, filed May 19, 2023 and entitled “Application of Underfilling BGA Devices in Two Phase Immersion Cooling;” U.S. Provisional Patent Application 63 / 589,509, filed October 11, 2023 and entitled “Under-Sided Stiffening Ring for BGA for Fluid Isolation;” U.S. Provisional Patent Application 63 / 581,260, filed September 7, 2023 and entitled “Edge Sealed Electronic Device for Immersion Cooling Environment and Methods for Making Same;” U.S. Provisional Patent Application 63 / 514,103, filed July 17, 2023 and entitled “Edge Sealed Electronic Device for Immersion Cooling Environment and Methods for Making Same;” U.S. Provisional Patent Application 63 / 503,401, filed May 19, 2023 and entitled “Edge Bonding for Immersion Cooling;” U.S. Provisional Patent Application 63 / 549,664, filed February 5, 2024 and entitled “Edge Sealed Electronic Device for Immersion Cooling Environment and Methods for Making Same,” each of which is incorporated by reference herein in its entirety.

[0031] FIGS. 2A-F illustrate several views of a computing system 200 including a conduit 240 for allowing trapped immersion cooling vapor to escape from cavity 216. Conduit 240 may be positioned and / or oriented in any suitable manner to allow immersion cooling vapor to escape from conduit 240. Substrate 220 may include a via through which conduit 240 is disposed.

[0032] Conduit 240 may be a tube, pipe, cylinder, or other suitable structure. Conduit 240 may be disposed on contact with one or more of device 210, substrate 220, sealant 230, or any suitable portion of computing system 200. Conduit 240 may be preferentially disposed such that a first end of conduit 240 is positioned away from substrate 220. This may prevent distillation products from depositing within cavity 216. This further provides a pressure relief mechanism for cavity 216 and prevents excess pressure from damaging or destroying device 210.

[0033] Conduit 240 may include a profile along a cross section that is circular, ovular, square, or any suitable profile shape. For example, conduit 240 may be a cylindrical tube having an outer diameter, an inner diameter, and a length along a longitudinal axis. An inner diameter of conduit 240 may be about 1 mm, between about 0.95 mm and about 1.05 mm, between about 0.9 mm and about 1.10 mm, between about 0.8 mm and about 1.2 mm, between about 0.5 mm and about 1.5 mm, between about 0.25 mm and about 2 mm, greater than about 0.9 mm, less than about 1.1 mm, equal to or greater than any of the aforementioned values, or any suitable diameter.

[0034] An outer diameter of conduit 240 may be about 1.1 mm, between about 1.05 mm and about 1.15 mm, between about 1 mm and about 1.2 mm, between about 0.9 mm and about 1.3 mm, between about 0.6 mm and about 1.6 mm, between about 0.4 mm and about 2.5 mm, greater than about 1 mm, less than about 1.2 mm, equal to or greater than any of the aforementioned values, equal to or less than any of the aforementioned values, or any suitable diameter.

[0035] A length of conduit 240 may be about 5 mm, about 8 mm, about 10 mm, about 15 mm, about 20 mm, about 50 mm, about 100 mm, between about 5 mm and about 10 mm, between about 8 mm and about 15 mm, between about 10 mm and about 20 mm, between about 15 mm and about 50 mm, between about 25 mm and about 75 mm, between about 50 mm and about 100 mm, equal to or greater than any of the aforementioned values, equal to or less than any of the aforementioned values, or any suitable length.

[0036] Conduit 240 may be made of any suitable material, including stainless steel, aluminum, copper, polymer, or the like. A material for conduit 240 may be selected for compatibility with an immersion cooling liquid. In an embodiment, conduit 240 may include one or more coatings to help prevent an accumulation of contamination and / or deposition of impurities dissolved in an immersion cooling liquid.

[0037] For example, when water is introduced to an immersion cooling system (for example, from the atmosphere when an immersion cooling tank lid is open or from an accidental spillage of water into an immersion cooling tank from cooling pipes), the water may mix with immersion cooling liquid and form acidic or corrosive compounds. These compounds may significantly disrupt the operation of components within an immersion cooling system or destroy componentsentirely. A coating in accordance with the present technology may help mitigate or impede a deposition or corrosion associated with a contaminant in an immersion cooling liquid in which computing system 200 is immersed.

[0038] FIGS. 2A and 2B illustrate a computing system 200 including conduit 240 in accordance with the present invention. FIG. 2B in particular illustrates a cutaway side perspective of computing system 200 with BGA 212 visible. Components of computing system 200 may be the same as or similar to analogous components of computing system 100. Conduit 240 may be disposed through substrate 220 and provide a fluidic coupling between cavity 216 and an environment surrounding computing system 200. In an embodiment, conduit 240 may be a hole or hollow trace through the substrate 220.

[0039] Conduit 240 may be disposed such that a longitudinal axis 242 is perpendicular to a surface of device 210. Computing system 200 may be oriented such that longitudinal axis 242 of conduit 240 is oriented parallel to a vector in the direction of gravity. However, any suitable orientation may be acceptable, including an orientation of computing system 200 such that longitudinal axis 242 is perpendicular to a vector in the direction of gravity.

[0040] FIGS. 2C and 2D illustrate an embodiment of computing system 200 in which conduit 240 is disposed near a bottom portion of computing system 200 (in a direction of gravity). Conduit 240 may be angled or bent such that a first longitudinal axis 242 along a first portion of conduit 240 is perpendicular to a surface of device 210, while a second portion of conduit 240 is perpendicular to the first portion of conduit 240.

[0041] FIGS. 2E and 2F illustrate an embodiment of computing system 200 in which conduit 240 is disposed in a direction of gravity. In such an embodiment, computing system 200 may be oriented analogously to computing system 100 and longitudinal axis 242 is aligned with a vector in the direction of gravity. This may prevent immersion cooling liquid from easily flowing back into cavity 216 and adding to potential contamination.

[0042] In FIGS. 2E and 2F, conduit 240 may be disposed through sealant 230. In an embodiment, conduit 240 may be placed on substrate 220 and sealant 230 may be placed around it while sealing device 210, serving to additionally seal conduit 240 in place.

[0043] FIGS. 3 A and 3B illustrate aspects of conduit 240 including longitudinal axis 242, inner diameter 244, and outer diameter 246. Longitudinal axis 242 may run through a centroid of conduit 240.

[0044] FIG. 4 depicts aspects of an immersion cooling system 400 for dissipating heat from one or more heat-generating components such as semiconductor die packages 405 via immersioncooling. Each package 405 can include one or more semiconductor dies that produce heat when the system is in operation. The immersion cooling system 400 in the illustrated example of FIG. 4 is a two-phase immersion cooling system, though the invention may also be implemented in a single-phase immersion cooling system.

[0045] Immersion cooling system 400 includes a container such as tank 420 filled, at least in part, with immersion cooling liquid 464. The immersion cooling system 400 can further include at least one chiller 480 that flows a heat-transfer fluid through at least one condenser tube 470 that is disposed in the tank 420 and headspace 408. Condenser tubes 470 and chiller 480 may be part of a heat exchanger. The packages 405 can be mounted on one or more printed circuit boards (PCBs) 457 that are immersed, at least in part, in the immersion cooling liquid 464. Immersion-cooling system 400 may further include a filter 475 disposed adjacent to the tank 420. Package 405 may be analogous to computing system 100 and / or computing system 200 of the present technology and include edge bonding sealant and one or more conduits for relieving pressure in accordance with the present technology.

[0046] Filter 475 may include a filtration media, a housing, and a pump configured to force immersion cooling liquid 464 through filter 475 to remove contaminants, particulates, or other impurities that may be added to immersion cooling liquid 464 during use. Filter 475 may be housed outside of tank 420 while being in fluidic communication with immersion cooling liquid 464 in tank 420. Alternatively, filter 475 may be submerged within immersion cooling liquid 464 inside of tank 420.

[0047] Immersion cooling liquid 464 may be a hydrocarbon, a fluoroketone, an oil, or a similar dielectric liquid that will act as an insulator while simultaneously transferring heat from package 405 more efficiently than air. An example of immersion cooling liquid 464 is Novec™ 649 produced by 3M™. An exemplary immersion cooling liquid 464 used in accordance with embodiments of the present invention may have a dielectric constant baseline value of about 1.8- 2 at a frequency of about 1 kHz.

[0048] In an embodiment of the invention, immersion cooling liquid 464 may be considered unacceptably contaminated if the dielectric constant and / or dielectric loss tangent of immersion cooling fluid being used in an immersion cooling system 400 differs by a threshold amount as compared to unused or pure immersion cooling liquid 464. For example, immersion cooling liquid 464 may be considered unacceptably contaminated or degraded if the dielectric constant and / or dielectric loss tangent differs by a threshold of 10% or more as compared to unused or pure immersion cooling liquid 464. In an embodiment, a dielectric constant and / or dielectric loss tangent variation threshold may be 20%, 15%, 5%, 3%, 1%, or any suitable threshold.

[0049] Contamination of the immersion cooling liquid 464 and resulting changes to dielectric constant and / or dielectric loss tangent may alter or negatively impact operation of components within immersion cooling liquid 464 including semiconductor die(s) 450. An altered dielectric constant and / or dielectric loss tangent may result in undesirable cross-talk between components on a PCB, additional noise or reduction in signal strength transmitted along exposed wires of a PCB or semiconductor die(s) 450 submerged in immersion fluid, and / or signal dissipation through the immersion cooling liquid 464. Signal loss may be severe enough that two elements may be effectively represented as being separated by an open circuit despite being physically connected. In an embodiment, a dielectric constant and / or dielectric loss tangent variation threshold may be selected based on an observed or inferred effect on one or more submerged semiconductor die(s) 450. For example, an increase in PCIe bit error rate above an error rate baseline may be correlated with an increase in dielectric constant and / or dielectric loss tangent above a dielectric constant and / or dielectric loss tangent baseline. Accordingly, operation of semiconductor die(s) 450 may be throttled or suspended when a dielectric constant and / or dielectric loss tangent of immersion cooling liquid 464 exceeds a predetermined threshold.

[0050] Changes to dielectric constant and / or dielectric loss tangent may be caused by contaminants within immersion cooling liquid 464. In some cases, changes to dielectric constant and / or dielectric loss tangent may be reversed by filtering the contaminants from immersion cooling liquid 464. In some embodiments, upon detecting an increase in dielectric constant and / or dielectric loss tangent of immersion cooling liquid 464, controller 402 may instruct filter 475 to increase filtration throughput or notify a user that an immersion cooling liquid 464 filtration media may need to be replaced. If a dielectric constant and / or dielectric loss tangent exceeds a predetermined threshold, controller 402 may throttle or shut down one or more semiconductor die(s) 450, generate a notification that immersion cooling liquid 464 should be replaced, trigger an alarm, etc.

[0051] The illustrated example of FIG. 4 is not intended to be to scale. The immersion cooling system 400 may house and provide immersion cooling liquid 464 to tens, hundreds, or even thousands of packages 405. In some cases, the immersion cooling system 400 can be small (e.g., the size of a floor unit air conditioner, approximately 1 meter high, 0.5 meter width, 0.5 meter depth or length). In some implementations, the immersion cooling system can be large (e.g., the size of a van or larger, approximately 2.5 meters high, 2.5 meters width, 4 meters depth or length).

[0052] The immersion cooling system 400 can also include a controller 402 (e.g., a microcontroller, programmable logic controller (PLC), microprocessor, field-programmable gatearray, logic circuitry, memory, or some combination thereof) to manage system operation. Controller 402 can perform various system functions such as monitoring temperatures of system components, cooling fluid level, tank access, chiller operation etc. The controller 402 can further issue commands to control system operation such as executing a start-up sequence, executing a shut-down sequence, assigning workloads among the packages, changing cooling fluid level, changing the temperature of the heat-transfer fluid circulated by the chiller 480, etc. In some implementations, controller 402 can include (or itself be) a baseboard management controller (BMC) 404. That is, the BMC 404 may monitor and control all aspects of system operation for the immersion cooling system 400 in addition to monitoring and controlling workloads of the semiconductor dies 450 in the packages 405 cooled by the system. The immersion cooling system 400 can also include a network interface controller (NIC 403) to allow the system to communicate over a network, such as a local area network or wide area network. The immersion cooling system 400 can further include a fluid sensor array 490 having a plurality of fluid sensors 410. Fluid sensors 410 may include one or more leak detection sensors at least partially submerged in immersion cooling liquid 464.

[0053] The semiconductor die(s) 450 and can be mounted on and attached to a printed circuit board (PCB) 455 (sometimes referred to as a substrate) in device package 405. The package 405 can be made commercially available as an off-the-shelf (OTS) product. The package 405 can be used for single-phase or two-phase immersion cooling of at least one semiconductor die 450, such as a microprocessor (e.g., a central processing unit (CPU) and / or graphics processing unit (GPU)), voltage regulator (VR), high bandwidth memory (HBM), a digital signal processing (DSP) die, an artificial intelligence (Al) accelerator, an application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), and / or other densely patterned semiconductor die.

[0054] In the two-phase immersion cooling system 400 of FIG. 4, heat flows from the semiconductor die 450 where it is generated into the heat spreader 452. The heat spreader 452 is in thermal contact with an immersion cooling liquid 464 that can flow over and extract heat from the heat spreader 452. The amount of heat delivered by the heat spreader 452 to the immersion cooling liquid 464 is enough to boil the immersion cooling liquid 464 that contacts the heat spreader 452 (creating bubbles 465 and potentially creating froth 467 when bubbles 465 reach the surface of immersion cooling liquid 464). The vapor 466 from the boiled immersion cooling liquid 464 can be cooled and condensed back to liquid droplets 468, for example, by the condenser tube 470. The heat-transfer fluid, such as chilled water, from the chiller 480 can be circulated through the condenser tube 470 to lower the temperature of the condenser tube 470below the condensation point in the headspace 408 of the tank 420. As a result, vapor 466 condenses on exterior surfaces of the condenser tube 470 and liquid droplets 468 from the condensed vapor can drip and / or flow back to the immersion cooling liquid 464. There may be a plurality of condenser tubes 470 in tank 420 to condense the vapor 466 into droplets. Some or all of the condenser tubes 470 may or may not be located directly over the PCBs 457. Instead, the condenser tube(s) 470 can be located near one or more walls of the tank 420, such that the condenser tube(s) 470 are not directly over the PCBs 457 on which the packages 405 are mounted.

[0055] To improve thermal performance in two-phase immersion cooling system 400, the heat spreader 452 can include a boiling enhancement coating (BEC) on at least one surface. The BEC can be formed from copper or a copper alloy and can be porous, for example, though BECs can take various forms. In some cases, the BEC is a micro porous copper coating having a thickness from approximately or exactly 50 microns to 500 microns thick (which may be produced by electroplating and / or etching). In some implementations, the BEC comprises a mesh copper layer bonded (e.g., via resistance heating) to at least an outer surface of the heat spreader 452. In some cases, the BEC is applied as particulates to at least one smooth surface of the heat spreader 452 and then subsequently sintered to adhere to one another and to the heat spreader 452. The BEC provides an improved surface area to contact the immersion cooling liquid 464 and can increase the heat transfer coefficient from the heat spreader 452 to the immersion cooling liquid 464 by up to a factor of 15 versus a smooth surface on the heat spreader 452. Accordingly, BECs can increase thermal conductivity to, and accelerate the boiling of, the immersion cooling liquid 464.

[0056] Further implementations of boiling enhancement coatings and enclosures are possible. Additional arrangements, applications, and methods of use of boiling enhancement coatings and enclosures, including with semiconductor dies and 3DIC stacks, are described in the below U.S. Patent Applications.

[0057] U.S. Patent Application No. 18 / 327,615, filed June 1, 2023 and entitled "Boiler Enhancement Coatings with Active Boiling Management,” discloses heat spreader and boiling enhancement enclosure architectures thermally and / or mechanically coupled to one or more semiconductor dies or logic ICs that may be used for passive and / or active management of immersion cooling fluid boiling, including through the use of valves to control pressure of boiling immersion cooling fluid within a boiling enhancement chamber, particularly in paragraphs

[0018] -

[0039] and FIGS. 3-5B. The entirety of U.S. Patent Application No. 18 / 327,615 is incorporated herein by reference.

[0058] U.S. Provisional Patent Application No. 63 / 500,167, filed May 4, 2023 and entitled “Direct to Chip Heat Spreader and Boiler Enhancement Coatings for Microelectronics,” discloses heat spreader and BECs thermally and / or mechanically coupled to one or more semiconductor dies, logic ICs, and / or 3DIC stacks, particularly in paragraphs

[0015] -

[0033] and FIGS. 2A-4. BEC form factors may include graphite heat spreader architectures, vapor chambers, heat pipes, copper plates, fins, and the like. BEC form factors may be thermally and / or mechanically coupled to the one or more semiconductor dies, logic ICs, and / or 3DIC stacks through a thermally conductive epoxy, and may have varying dimensions relative to a surface to which the semiconductor dies and / or logic ICs are mounted. The entirety of U.S. Provisional Patent Application No. 63 / 500,167 is incorporated herein by reference.

[0059] U.S. Patent Application No. 18 / 460,091, filed September 1, 2023 and entitled “Direct to Chip Application of Boiling Enhancement Coating,” discloses BECs and methods for applying BECs to semiconductor dies, logic ICs, and / or 3DIC stacks in accordance with the present technology. In particular, paragraphs

[0024] -

[0046] and FIGS. 2A-5 disclose embodiments of BEC layers, adhesives, solders, sintering, laser ablation, meshes, and other BECs and BEC application methods. The entirety of U.S. Patent Application No. 18 / 460,091 is incorporated herein by reference.

[0060] U.S. Provisional Patent Application No. 63 / 506,945, filed June 8, 2023 and entitled “Vapor- Shedding Structures for Boiler Plates in Two-Phase Immersion Cooling Systems,” discloses structures that may be thermally and / or mechanically coupled to computing hardware such as one or more semiconductor dies, logic ICs, and / or 3DIC stacks to enable the shedding of immersion cooling vapors generated from the boiling of immersion cooling fluid during operation of the computing hardware. In particular, paragraphs

[0021] -

[0039] and FIGS. 3A-5 disclose vapor-shedding structures including varying porosities, constituent materials, and geometries relative to the computing hardware on which they are mounted. The entirety of U.S. Provisional Patent Application No. 63 / 506,945 is incorporated herein by reference.

[0061] U.S. Provisional Application No. 63 / 513,828, filed July 14, 2023 and entitled “Grinding Apparatuses and Methods for Mechanically Modifying Surfaces of Processors to Promote Boiling of a Coolant Liquid,” discloses methods for creating boiling enhancement modifications to surfaces such as the surfaces of computing hardware such as one or more semiconductor dies, logic ICs, and / or 3DIC stacks, particularly in paragraphs

[0036] -

[0095] and FIGS. 2A-8. For example, grooves, patterns, gouges, trenches, or other structures may be added to a surface or lid of a processor, semiconductor die, logic IC, 3DIC stack component, and / or BEC to encourage nucleation sites for bubbles of immersion cooling vapor to form during a cooling process, thusdecreasing the thermal resistance between the processor, semiconductor die, logic IC, and / or 3DIC stack component and the surrounding immersion cooling fluid. The entirety of U.S. Provisional Application No. 63 / 513,828 is incorporated herein by reference.

[0062] U.S. Provisional Patent Application No. 63 / 513,829, filed July 14, 2023 and entitled “Electrical Connector Having a Heater to Facilitate Boiling of a Coolant Liquid to Improve Signal Integrity in Immersion Cooling Environment,” discloses heaters for promoting boiling of immersion cooling fluid near electrical connectors such as connections between components of a 3DIC stack and enable improved impedances at those connectors, particularly in paragraphs

[0019] -

[0052] and FIGS. 1 A-3B. The entirety of U.S. Provisional Patent Application No. 63 / 513,829 is incorporated herein by reference.

[0063] U.S. Provisional Patent Application No. 63 / 603,242, filed November 28, 2023 and entitled “Woven Boiler Enhancement Coatings,” provides additional examples of BECs including woven BECs with variable weave patterns, densities, attachment mechanisms, and materials (including copper and tungsten) that may be attached to computing hardware such as one or more semiconductor dies, logic ICs, and / or 3DIC stacks in order to promote more efficient heat transfer and immersion cooling vapor nucleation, particularly in paragraphs

[0031] -

[0055] and FIGS. 3-7. The entirety of U.S. Provisional Patent Application No. 63 / 603,242 is incorporated herein by reference.Conclusion

[0064] While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the function and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the inventive teachings is / are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination oftwo or more such features, systems, articles, materials, kits, and / or methods, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0065] Also, various inventive concepts may be embodied as one or more methods, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0066] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0067] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0068] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0069] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consistingessentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0070] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0071] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

CLAIMS1. A computing system configured for immersion in a coolant liquid of a two-phase immersion cooling system, the computing system comprising: a substrate; a device mounted to the substrate, the device comprising an integrated circuit; a sealant directly coupled to the substrate and the device and disposed along at least a portion of each edge of the device, such that the sealant, the device, and the substrate together form a cavity configured to trap one or more bubbles of a gas when the computing system is immersed in the coolant liquid; and a conduit configured to provide a fluidic connection between the cavity and an environment surrounding the computing system.

2. The computing system of claim 1, wherein the conduit is disposed in contact with at least one of the substrate, the device, or the sealant.

3. The computing system of claim 1, wherein the conduit comprises an inner diameter equal to or less than 1 mm.

4. The computing system of claim 1, wherein the conduit comprises a length equal to or greater than 10 mm.

5. A method for vapor management, the method comprising: generating, by a device attached to a substrate and immersed in immersion cooling liquid, waste heat; vaporizing, by the waste heat, a portion of the immersion cooling liquid to create immersion cooling vapor in a cavity, the cavity being formed between the substrate, the device, and a sealant directly coupled to the substrate and the device; and directing at least a portion of the immersion cooling vapor out of the cavity through a conduit, the conduit fluidically coupling the cavity to an environment surrounding the device.

6. The method of claim 5, wherein the conduit is disposed in contact with at least one of the substrate, the device, or the sealant.

7. The method of claim 5, wherein the conduit comprises an inner diameter of equal to or less than 1 mm.

8. The method of claim 5, wherein the conduit comprises a length equal to or greater than 10 mm.

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