Closed liquid cooling system

Abstract

A liquid cooling system includes a printed circuit board, a gasket on a top side of the printed circuit board surrounding one or more components on the printed circuit board, a housing on the gasket and secured against the printed circuit board to form a sealed chamber, and a transfer liquid on the sealed chamber, and the transfer liquid contacts one or more components mounted on the printed circuit board within the sealed chamber to provide cooling for the one or more components.

Description

Technical Field

[0001] This application relates to thermal management systems, and more specifically to liquid-cooled housings integrated with printed circuit boards (PCBs) to dissipate heat generated by electronic components. Background Technology

[0002] Integrated circuits (ICs), such as central processing units (CPUs), systems-on-a-chip (SOCs), graphics processing units (GPUs), tensor processing units (TPUs), neural processing units (NPUs), field-programmable gate arrays (FPGAs), and application-specific integrated circuits (ASICs), power transistors, DC-DC converters, power controllers with integrated switching transistors, triacs, thyristors, diode bridge rectifiers, insulated-gate bipolar transistors (IGBTs), voltage regulators, motor drivers, power factor correction (PFC) circuits, and load switches, generate heat during operation. These components must be properly cooled to maintain optimal performance and prevent failure.

[0003] In previous technologies, various heat dissipation methods have been used to absorb and remove heat from the IC and redistribute that heat away from the hardware.

[0004] Traditionally, cooling methods rely on a combination of heat sinks and fans, where air flows over the heat sink to dissipate heat. However, such methods are often insufficient to manage the thermal demands of modern high-performance components.

[0005] A prior art solution is liquid cooling. In this system, a liquid (such as water or a specialized dielectric fluid), instead of air, circulates to remove heat. The system typically consists of a substrate attached to the CPU's metal casing via thermal paste. The substrate forms the portion of the water block, which is filled with coolant. As the coolant absorbs heat from the substrate, the heat is transferred through the water block and then directed to a heatsink. At the heatsink, the liquid is exposed to air for cooling, typically accelerated by a fan. The coolant then re-enters the water block, completing the cycle.

[0006] Semiconductor components exhibit characteristics known as thermal runaway; in which power consumption increases exponentially with rising temperature. As the die temperature rises, the power required to perform the same computational operations increases, thus exacerbating the thermal load. Without effective heat removal, this thermal runaway can gradually escalate, leading to the reaching of critical temperature levels in the semiconductor system.

[0007] Traditionally, cooling semiconductor dies involves two methods. The first involves heat dissipation through the top surface of the die, where thermal paste bridges the die to a metal heatsink cooled by air or liquid. The second method utilizes a ground pad connected to the package via gold wires, which in turn connects to a printed circuit board (PCB). This allows some heat to be transferred from the die to the PCB through pins or balls. While relatively inefficient, even these small contributions can help alleviate thermal problems in high-performance systems.

[0008] The combined effect of these traditional cooling methods follows the superposition principle, meaning that each thermal gradient (any interface or material transition with a temperature difference) contributes to reducing the internal temperature of the semiconductor grain. However, even with the most advanced conductive cooling technologies available today, high-performance semiconductor devices typically exhibit internal grain temperatures exceeding 100°C in an ambient environment of 30°C.

[0009] To further manage grain temperature, many systems include thermal sensors that monitor temperature levels and initiate throttling or other thermal management strategies when approaching critical thresholds.

[0010] Although immersion cooling has been practiced in the electronics industry for many years, it presents several drawbacks because the entire motherboard or sub-components must be submerged in a liquid bath. In such configurations, interconnects such as wires and cables must be kept out of the liquid, resulting in complex and often cumbersome installation. Furthermore, the large volume of liquid required makes the system expensive, prone to evaporation losses, and difficult to manage. Attached Figure Description

[0011] The invention is illustrated in the accompanying drawings by way of example rather than limitation, wherein similar reference numerals refer to similar elements, and in the drawings:

[0012] Figure 1 This is a top view of an exemplary configuration of a liquid cooling system.

[0013] Figure 2A and 2B This is an exploded view of an exemplary configuration of a liquid cooling system.

[0014] Figure 2C This is a view of an exemplary configuration of a printed circuit board that includes some components and spacers.

[0015] Figures 3A-3C These are cross-sectional views of different embodiments of the gasket and housing.

[0016] Figure 4 This is a cross-sectional view of one embodiment of a liquid cooling system.

[0017] Figure 5A and 5B This is an internal view of an exemplary version of the top and bottom of the casing.

[0018] Figure 6A It is a cross-sectional view of a liquid cooling system with symmetrical attachments.

[0019] Figure 6B This is a schematic diagram simulating the movement of liquid transferred inside the shell.

[0020] Figure 6C This is a schematic diagram simulating heat dissipation inside the casing.

[0021] Figure 7A and 7B This is a perspective view of the front and rear of the housing of a liquid cooling system configuration.

[0022] Figure 8A This is a schematic diagram of a liquid cooling system that includes a filling valve for a single-sided system and a conformal coating.

[0023] Figure 8B This is a flowchart of various embodiments of a liquid-filled cooling system.

[0024] Figures 9A-9F This is a schematic diagram of a liquid cooling system.

[0025] Figure 9G An example of intra-chip cooling is shown, where the liquid flow-hole does not pass through the encapsulation molding of the integrated circuit package.

[0026] Figures 10A-10C This is a schematic diagram of an embodiment of using a liquid cooling system for in-chip cooling.

[0027] Figure 10D Examples of in-chip cooling are provided for systems that include chiplets in integrated circuit packages.

[0028] Figure 11A-11B This is a schematic diagram of a flip-chip type packaging with liquid flow holes.

[0029] Figure 12 This is a schematic diagram of the cross-section of the chip, where the liquid flow holes are connected to the inner plane of the PCB.

[0030] Figures 13A-13C These are schematic diagrams of various embodiments of a system including a liquid driver.

[0031] Figures 14A-14C This is a schematic diagram of one embodiment of a liquid cooling system that provides electrical isolation.

[0032] Figure 15 This is a flowchart of a liquid cooling system designed using electronic design automation (EDA) tools.

[0033] Figure 16 It is a block diagram of a computer system that can be used with this system. Detailed Implementation

[0034] This invention describes a liquid cooling system comprising a housing coupled to a printed circuit board using gaskets. The housing is filled with a transfer liquid having a high heat transfer coefficient but being non-conductive (i.e., electrically insulating). The transfer liquid can be single-phase or two-phase. The system provides board-level cooling, cooling one or more chips on the printed circuit board. In various embodiments, the system provides inter-chip cooling by providing improved cooling through inter-chip liquid flow orifices beneath the components, ensuring contact between the transfer liquid and the bottom portion of one or more components on the printed circuit board. In some embodiments, the system can provide intra-chip cooling using flow orifices through an integrated circuit package, allowing the transfer liquid to flow closer to the heat source. Intra-chip cooling allows the transfer liquid to enter the circuit package. In some embodiments, the transfer liquid is in direct contact with the die within the integrated circuit package. Additionally, the housing protects the components from radiation.

[0035] Electronic design automation (EDA) tools can be used to design the housing for the liquid cooling system, including its positioning, dimensions, and other configuration details. These EDA tools can be integrated into existing EDA systems, allowing for printed circuit board layout design that takes into account factors such as liquid orifices, enclosures, positioning, and others. In this context, liquid orifices are holes in a printed circuit board or component package through which liquid can be transferred.

[0036] This system offers the advantages of immersion cooling, but limits the coolant to a subset of the system. This subset includes components requiring thermal management. The system of this invention encloses the transfer fluid within a sealed system, ensuring that the transfer fluid does not leak or evaporate. The transfer fluid does not need to be replenished during the product's lifespan.

[0037] Closed-loop liquid cooling systems significantly enhance bottom-side cooling of semiconductor components, replacing the traditional inefficient method of top-side cooling, while also improving heat transfer from the bottom.

[0038] In various embodiments, the transfer liquid contacts the bottom of the chip, allowing direct liquid cooling of all sides of the die and effectively cooling the pins, balls, and surface areas beneath the chip. It also cools the PCB itself. Through strategically placed liquid orifices, it cools the internal planes of the PCB, allowing for more uniform heat dissipation throughout the system with a smaller thermal gradient. Furthermore, the positioning of the liquid orifices provides a path for the transfer liquid to move around the interior of the chamber or housing, increasing heat transfer from the components.

[0039] This method offers a synergistic effect: as the internal temperature of the grain decreases, its power consumption also decreases, resulting in a reverse thermal runaway effect. Reduced power consumption further lowers the temperature (or limits or prevents temperature rise), thereby enhancing the overall energy efficiency of the system. Therefore, this system offers multiple technical advantages, enhanced efficiency, and improved performance. The system further improves durability, reliability, and stability because components are maintained at more efficient operating temperatures. Systems operating at a given performance level will operate at lower temperatures, reducing power consumption and improving overall energy efficiency. Systems designed for maximum performance can achieve higher output while consuming less power and maintaining thermal stability.

[0040] As semiconductor die sizes shrink and / or more dies are integrated onto a single chip, power density increases, resulting in increased heat generation in a smaller area. Closed-loop liquid cooling systems allow for more efficient heat transfer throughout the entire system, including multiple dies, chips, power delivery components, and the PCB itself, thereby improving the system's overall power consumption, thermal management, and power density.

[0041] In various embodiments, the system of the present invention includes a thermal sensor for monitoring the die temperature. In some embodiments, once the die reaches a critical temperature, performance throttling is initiated to prevent further thermal runaway. The system reduces the workload on the die, stabilizing the temperature at an equilibrium point where maximum permissible performance can be maintained without overheating the chip. In other cases, such as during overclocking, the die performance is intentionally increased beyond recommended levels. This intentional overclocking results in increased power consumption and heat generation, requiring careful monitoring and control to ensure the temperature remains within safe operating limits.

[0042] Furthermore, as the demand for computing power continues to grow, so too does the power consumption of data centers worldwide. By integrating enclosed liquid cooling technology into individual chips and compute nodes within data centers, overall power consumption can be reduced. This reduction in power demand not only improves the efficiency of individual data centers but also helps to reduce the overall energy footprint required for computing power.

[0043] The following detailed description of the invention refers to the accompanying drawings, wherein similar reference numerals denote similar elements, and various embodiments of the invention are illustrated by way of example. The description of these embodiments is detailed enough to enable those skilled in the art to practice the invention. Those skilled in the art will understand that various embodiments may be applied in different configurations, and that logical, mechanical, electrical, functional, and other modifications may be made without departing from the scope of the invention. Therefore, the following detailed description should not be considered limiting, and the scope of the invention is defined only by the appended claims.

[0044] Figure 1 This is a top view of a configuration of a liquid cooling system. The liquid cooling system includes a housing, also known as a chamber. (Only in...) Figure 1A partially visible housing 100 covers a portion of a printed circuit board 130, which includes a heat-generating chip (or component) 105. As will be explained, this housing works with other components to define a housing volume, which may be referred to as a chamber. The housing is typically attached using mounting holes 140. The system has a rubber seal or gasket 115 used to provide a leak-proof seal between the printed circuit board 130 and the housing, i.e., forming a seal through which transfer liquids cannot pass. The gasket is located on the PCB, although there may not be any mounting slots on the PCB. The housing is located on the gasket. Mounting slots may be provided on the housing to facilitate the placement and positioning of the gasket on the PCB. In various embodiments, outer silkscreen lines 120 and inner silkscreen lines 125 provide mounting slots that define the location for the gasket 115. The silkscreen lines provide positioning for the housing and ensure that the housing is leak-proof. The use of silkscreen lines 120 and 125 also allows PCB trace 135 to be guided under the housing and pads as a through-type PCB trace 137 without creating gaps. The housing is filled with a transfer fluid used to transfer heat from the assembly 105 to the heat sink (not shown).

[0045] The transfer liquid flows in a convection mode, moving heat from chip 105 to metal housing 100, which includes fins for heat dissipation. Liquid flow orifices 110 are dispersed in a pattern to optimize the movement of heat from the chip to the exterior of the housing. Hotter material or gas rises, creating a temperature difference between the heated transfer fluid and the cooler exterior of the housing, inducing liquid flow within the housing. In various embodiments, the transfer liquid may be used in only one phase, meaning it remains in liquid form throughout the process. Here, the entire volume of the chamber is filled with the transfer liquid in liquid form. In another embodiment, the transfer liquid may transition between phases, wherein the transfer liquid transforms from liquid to gas at a specific location heated above its boiling point, and then transforms back to liquid as the gas flows into a region where it cools below that boiling point. This can increase the level of convection because the gas rises faster than the heated liquid due to its lower density.

[0046] Perfluorinated compounds (PFCs) and perfluorinated carbons can be used as transfer liquids. In one embodiment, 3M... TM The company's Fluorinert TMElectron fluids can be used as transfer fluids. One example of such a fluid is FC-72, which has a boiling point (the phase transition point between liquid and gas) of 56 degrees Celsius at atmospheric pressure. This means that if a semiconductor embedded in this fluid is heated to a temperature exceeding this boiling point of 56 degrees Celsius on its outer surface, the fluid within the casing, at atmospheric pressure, will cause the fluid to boil (transform into a gas) around the top, sides, and bottom surfaces of the semiconductor. The gas will then bubble up against gravity, causing it to flow away from the chip and cool as it mixes with the cooler fluid, while new, cooler fluid flows into the surface around the chip. At higher pressures, the liquid-to-gas phase transition will occur at higher temperatures. Other non-conductive fluids can also be used.

[0047] The housing is designed to cover an enclosed assembly group 150 including one or more heat-generating components 105 and exclude external components 155, which may include edge connectors 175, through-hole connectors 170, surface mount connectors 165, and power connectors 160. In various embodiments, for a two-sided housing, one or more liquid flow holes 110 allow liquid to circulate between the two sides of the printed circuit board.

[0048] The design may include more or fewer excluded components 155 or enclosed components 150. Configurations excluding excluded components are also possible, where the housing covers the entirety of one or both sides of the PCB. This configuration can be used, for example, with a PCB using a PCI (External Device Interconnect) high-speed bus. In this configuration, the PCB is designed to insert into a PC motherboard, and the PCB has no external components because all computational instructions pass through the PCI high-speed bus.

[0049] The system may not include silkscreen lines or may include single lines with a pad positioned above them. In a single-sided housing, there may be no liquid flow holes because the transfer liquid does not move between the sides of the PCB.

[0050] Figure 2A and 2B This is an exploded view of an example configuration of a liquid cooling system. The illustrated system is... Figure 2A The exploded front view 200 of the double-sided shell is provided, as well as in Figure 2BThe system provides an exploded perspective or isometric view of the dual-sided housing. The system shows a printed circuit board 240 with two rubber gaskets 230, 250, to which a top housing 220 and a bottom housing 260 are coupled. In various embodiments, screws 270 are used to attach the bottom chamber 260 to the top chamber 220 through mounting holes in the PCB 240. The screws may be oriented from the top and / or bottom. The screws may terminate within the housing. The screws may be replaced by rivets or other fasteners. Housings 220 and 260 are fastened to the PCB 240 by fastening each other. They are also fastened to the PCB, thus forming a leak-proof housing.

[0051] The housing can be made of any material with high thermal conductivity. In various embodiments, the housing is made of aluminum, graphite, ceramic, and / or aluminum oxynitride. The housing can also be made of another material that is thermally conductive but not electrically conductive. Housings 220, 260 are in contact with the transfer fluid, and heat moves from the transfer fluid to the housing, where it is dissipated into the space. The top housing 220 and / or the bottom housing 260 may have fins, needle fins, or other components for better heat dissipation. An optional external fan 210 may also be used. Alternatively, external liquid cooling may be used, or instead of using a fan and airflow to dissipate heat from the housing. Other methods of heat dissipation from outside the housing may be used.

[0052] Printed circuit board 240 and pad 230 in Figure 2C It is shown in more detail in the middle. Figure 2C A perspective view of the printed circuit board is illustrated, showing the spacer correctly positioned. It can be seen that some components are located within the housing. These components are within the area defined by the spacer. The spacer surrounds these components because it encircles them in its plane. It can be seen that some other components are outside the housing (e.g., outside the rubber spacer defining the edge of the housing). In various embodiments, these other components are used to couple the printed circuit board and its components to other components of the computer system. In addition to I / O (input / output) components, or alternatives to I / O components, other components on the PCB may also be located outside the housing.

[0053] Figures 3A-3C These are cross-sectional views of various embodiments of the gasket and housing. Figure 3A An example of housing 310 is shown, which is coupled to a printed circuit board 345 using mounting screws 340. Two parallel silkscreen layers 350 define the locations for gaskets or rubber seals 315. Housing 310 includes threaded holes 320 to receive mounting screws 340. Gaskets 315 and silkscreen layers 350 are located on top of solder mask 325, which covers a copper layer with traces 330 and is located on top of PCB dielectric layer 335.

[0054] Figure 3BAn example configuration using a single silkscreen layer 360 is shown, with a gasket 315 positioned on top of the single solid silkscreen layer 360. This silkscreen layer provides positioning guidance and a smooth surface to ensure that the cavity defined by the housing 310 is leak-proof.

[0055] Figure 3C An example configuration without a silkscreen layer is shown, where a gasket rests on top of the solder mask layer 325.

[0056] A gasket provides a seal between the chamber and the printed circuit board to create a leak-proof seal that prevents liquid from passing through. This seal may be referred to as leak-proof or waterproof, although the transferred liquid is not water, and the required level of sealing for a transferred liquid can differ at a given pressure difference compared to water. Furthermore, the leak-proof seal does not allow the transferred liquid to leak in gaseous form. The gasket maintains a seal between components under various operating conditions, ensuring consistent and effective performance. The gasket may be made of rubber, silicone, foam, or other sealing materials. In various embodiments, the gasket provides EMI / RFI blocking. This can be achieved using foam and wire mesh composites or other materials. The gasket may alternatively be made of a conductive material or may have a conductive outer surface to assist in preventing EMI leakage. In another embodiment, the system may include a first gasket for sealing and a second gasket for blocking electrical signals.

[0057] although Figures 3A-3C The illustration illustrates the configuration of the printed circuit board, copper layers, and solder mask layers; however, those skilled in the art will understand that the configuration of these components is not essential to the present invention. Instead, the system includes a housing that forms a chamber for enclosing all or part of the printed circuit board, using gaskets for a leak-proof seal between the housing and the PCB. The actual configuration of the layers on the PCB is irrelevant to this design, as are the dimensions and positions of the components on the PCB.

[0058] Figure 4 This is a cross-sectional view of a liquid cooling system having a top compartment and a bottom compartment. The system includes a top housing 410 coupled to a bottom housing 420. Housings 410 and 420 are made of aluminum, aluminum alloy, aluminum oxynitride (ALON), or other heat-transferring materials.

[0059] become

[0060] The housings 410 and 420 are coupled to a printed circuit board 440, which includes one or more heat-generating components (not shown). The printed circuit board 440 includes one or more holes 450 or liquid flow holes to allow transfer liquid to circulate between the top and bottom portions of the chamber. The liquid-filled chamber 460 is formed by the top and bottom portions of the housings. The housing assemblies 410 and 420 are coupled to the printed circuit board with rubber seals or gaskets 430 and 435 to ensure that the transfer liquid does not leak.

[0061] The shape of the chamber shown is defined by the shape of the enclosing components on a printed circuit board (not shown). In this configuration, one portion of the printed circuit board has taller components, and another portion has shorter components. The actual shape of the chamber can be modified to suit the configuration of the components on the printed circuit board.

[0062] In various embodiments, the outer surface of the housing may include fins 470, needle-like fins, and / or other protrusions to dissipate heat transferred by the transfer liquid filling the chamber. The fins are sized to maximize the cooling area, but are thick enough for ease of manufacture and stability without deformation, and still thin enough to maximize airflow and area. The system can use any configuration of fin or protrusion shape. One or more optional fans may be positioned on or near the top of the chamber. Other methods of heat dissipation from the chamber may be used.

[0063] The liquid cooling system utilizes advanced materials and structural enhancements to maximize the heat dissipation efficiency of the self-cooling chamber. In various embodiments, the housing is constructed of aluminum, chosen for its thermal conductivity and lightweight properties. In another embodiment, the housing is constructed of aluminum oxynitride, a transparent ceramic composite material comprising aluminum, often referred to as ALON (Al₂O₃). TM In one embodiment, the casing is made of graphite, ceramic, or a composite material.

[0064] To optimize heat dissipation, the housing may have thin walls, cooling ribs or fins, and / or surface treatments to increase its surface area. The housing walls can be as thin as 1 mm, providing rapid heat transfer without adding unnecessary weight. Cooling ribs, pins, and / or fins may be designed on its (multiple) outer surfaces. These structural features increase the surface area of ​​the housing, thereby promoting greater heat exchange between the housing and the surrounding air.

[0065] One or more surface treatments may be applied to the interior or exterior of the housing. Surface treatments may include sandblasting, powder coating, anodizing, emissive coatings, etc. The purpose of surface treatment is to increase heat transfer.

[0066] Aluminum surfaces can be sandblasted to create a rougher texture, thereby increasing the surface area available for heat dissipation. Sandblasting can be applied only to the outer surface of the housing, while the inner surfaces remain smooth to reduce turbulence in the transferred liquids.

[0067] Heat-resistant powder coatings can be applied to the exterior of the housing. This coating can be formulated to emit infrared radiation when heated, thereby improving heat transfer by radiating heat energy into the surrounding air.

[0068] Anodizing enhances aluminum's corrosion resistance and improves its heat transfer capabilities. The anodized layer also increases surface durability, especially in environments with moisture or chemicals. The inner surface of the housing can be anodized.

[0069] A specialized infrared-emitting coating can be applied to the exterior of the housing. When the housing heats up, the coating radiates heat in the form of infrared radiation, further improving overall heat dissipation from the system.

[0070] Other surface treatments can be applied to increase heat transfer to the housing.

[0071] By combining structural enhancements such as cooling ribs and sandblasting with advanced surface treatments such as powder coating or anodizing, the system significantly enhances its thermal management capabilities. The inclusion of an infrared-emitting coating provides additional mechanisms for heat transfer, utilizing radiation as a means of more effectively cooling the system.

[0072] In addition to these thermal benefits, the system's metal casing also improves the mechanical robustness of the PCB and protects enclosed components. The high-strength metal casing provides excellent protection against physical stresses such as vibration, shock, and external pressure. This increased durability not only protects electronic equipment from physical damage but also extends the product's lifespan in harsh environments. These design choices ensure that the system not only maximizes heat transfer from the internal fluid to the external environment but also contributes to improving the overall mechanical resilience, energy efficiency, and reliability of high-performance electronic equipment.

[0073] Figure 5A and 5B This is an internal view of a specific configuration of the top and bottom components of the housing. The housing includes a first liquid-filled compartment or chamber, which is a liquid chamber 520. The housing includes a mounting groove 530 for gaskets surrounding the liquid chamber 520. In one embodiment, the housing may also include a second compartment, namely protective cavities 525, 540 for components outside the liquid chamber 520. These protective cavities 525, 540 allow the housing to enclose the entire printed circuit board while keeping I / O ports and other connectors outside the liquid chamber 520. In one embodiment, a portion of the housing has open screw holes 560, while another portion has threaded screw holes 570 to receive screws that attach the housing portions to each other. In another embodiment, the top and bottom portions of the housing may each have two open screw holes and two threaded screw holes. In some embodiments, the top and bottom portions of the housing are symmetrical.

[0074] Figure 6AThis is a cross-sectional view of the liquid cooling system, showing symmetrical attachment. In this configuration, one of the mounting screws 635 passes through the top housing 610 and is inserted into a threaded hole in the bottom housing, and the other does the reverse. This configuration allows for the use of symmetrical chambers in the top housing 610 and bottom housing 620, each chamber being attached with rubber seals, namely a top seal 615 and a bottom seal 625. A top silkscreen layer 670 and a bottom silkscreen layer 675 define the locations for the top rubber seal 615 and the bottom rubber seal 625, respectively. It can be seen that the top and bottom housing assemblies appear identical in this cross-section. However, in some other embodiments, the two portions of the housing may have different shapes to accommodate the configuration of components on the PCB.

[0075] In various embodiments, the system includes one or more liquid flow holes 680 or liquid vias through a printed circuit board 660, including through a solder mask top 640, a traced copper layer top 650, a traced copper layer bottom 655, and a solder mask bottom 645. The liquid flow holes 680 allow transferred liquid for cooling components to circulate around the chamber. The PCB 660 may also include one or more component vias 685, also referred to as through-hole vias. Such component vias 685 are typically plated with metal to enable component connection.

[0076] Figure 6B This is a schematic diagram simulating the liquid flow inside the housing and the airflow outside the housing. It can be seen that the transfer liquid rises from the heat of the chip and cools as it reaches the outside of the chamber. The cooled transfer liquid then falls, creating convection illustrated by the lines shown. The transfer liquid used can be a two-phase transfer liquid, comprising a liquid phase and a gas phase in use. Here, most of the transfer liquid is in the liquid phase and some is in the vapor / gas phase. The transition from liquid to gas requires energy, and the reverse transition releases energy. Thus, during operation, the liquid absorbs heat, causing it to evaporate. It then condenses back into liquid at different locations, effectively transferring heat from one location within the system (specifically, the location of the heat-generating components) to another location within the system (specifically, the location where heat can be transferred out of the system).

[0077] Figure 6CAn example is shown of the hot zone of a chip inside the housing. It can be seen that once the heated transfer liquid moves away from the heat source (chip), it cools rapidly, and thus the circulating transfer liquid can be used to cool the chip, with a relatively small gap between the top of the chip and the top of the housing. This system optimizes the location and size of the liquid orifices, allowing the transfer liquid to flow between the top and bottom portions of the system. Simulations show that an orifice 1.5 mm below the circuitry performs better than a larger orifice because the increased flow rate through the smaller orifice improves cooling by supplying cooler liquid more quickly. In various embodiments, the size of the liquid orifice below the chip to be cooled is between 1 mm and 3 mm. The size of the liquid orifice in different locations can vary. The liquid orifice below the chip can be smaller than the liquid orifice on the PCB surrounding the chip(s). The maximum size of the liquid orifice below the chip is defined by the spacing between the BGA balls / contacts. The liquid orifices are designed not to interfere with the connection between the components and the printed circuit board.

[0078] Figure 7A and 7B This is a perspective view of the front and rear of an embodiment of a liquid cooling system with an assembled housing. The assembled housing 710 has fins on all four sides and provides openings for connectors to connect to other components. In the configuration shown, a fan 720 is integrated between the fins to increase airflow along the exterior of the housing 710.

[0079] Figure 8A This is a schematic diagram of a liquid cooling system including a filling valve and conformal coating for a single-sided system. In this configuration, the housing 810 is only on one side, and the opposite side of the PCB is coated with a conformal coating 830 or epoxy resin, which is leak-proof. Therefore, liquid 838 circulates only on one side of the printed circuit board 822. In this configuration, the heat-requiring component 826 is on one side of the printed circuit board 822. The conformal coating 830 may be epoxy resin, parylene, silicone coating, polyurethane, acrylic, fluoropolymer, or another leak-proof material that can withstand the transferred liquid and heat levels within the chamber. In one embodiment, one or more liquid flow holes 840 may be present in the printed circuit board 822. The liquid flow holes may provide improved cooling by contacting metal layers within the PCB, which are plated. The liquid flow holes 840 pass through the PCB, including through the solder mask 818 and the traced copper layer 820. In various embodiments, the housing 810 is coupled to the PCB 822 using mounting screws 814 in threaded holes 812. Rubber seal 816 ensures the connection between housing 810 and PCB 822. Two parallel silkscreen layers 824 define the location for rubber seal 816.

[0080] In various embodiments, housing 810 includes a fill valve 842. Fill valve 842 allows liquid 838 to be added into the interior of the cavity. Fill valve 842 includes one or more threaded holes into the housing. Once liquid has been filled to a specified level in the chamber, the fill valve is closed securely with a closing screw 844, closing bolt, plug, or another type of fastener. The fill valve may include a one-way valve element that allows liquid to enter through the valve but prevents liquid from exiting through the valve.

[0081] Figure 8B This is a flowchart of various embodiments of a liquid filling cooling system. The process begins at block 850. At block 855, the process determines whether a filling valve is being used. If yes, the process continues to block 880. If no filling valve is being used, the process continues to block 860.

[0082] At block 860, the housing is partially attached to the printed circuit board, leaving a gap. The screws are partially tightened, but enough space is left for the liquid.

[0083] At block 865, the housing and PCB are immersed in a transfer liquid bath, and at block 870, the transfer liquid fills the housing. The transfer liquid only partially fills the housing so that the two-phase transfer liquid can expand when it turns into a gas. Alternatively, if it is a single-phase transfer liquid that remains liquid at all relevant temperatures and does not expand when heated, the liquid can completely fill the housing.

[0084] At block 875, the housing is fully attached, providing a leak-proof seal to enclose the transfer liquid. The housing and PCB are then removed from the transfer liquid bath. The process concludes at block 899.

[0085] If the process determines to use a filling valve at block 855, the procedure continues to block 880.

[0086] At block 880, the process determines whether the filling valve is open. If not, the filling valve is opened at block 885. Note that in this configuration, the housing is fully attached before liquid is added. Therefore, the housing is sealed to the printed circuit board in a leak-proof manner.

[0087] In block 890, the fill valve is used to fill the chamber with liquid to the appropriate level. As noted above, the fill can be made to a level that allows for expansion of the transferred liquid, including two-phase transferred liquids (if used).

[0088] At block 895, the filling valve is sealed. The filling valve can be sealed using a screw, plug, or other component. The filling process may also include changing the pressure level within the housing. Changing the pressure within the housing may include removing some or all of the remaining air from the chamber using a vacuum pump to reduce the pressure within the chamber. Changing the pressure may further include adding additional air or another gas, which may be heavier or lighter than air, to increase the pressure within the chamber. By changing the pressure within the chamber, the flow pattern of the transferred liquid can be altered. The process then ends at block 899.

[0089] Figures 9A-9E These are schematic diagrams of various embodiments of cooling using a liquid cooling system. Figure 9A An illustration of a configuration with a single BGA chip 920 is shown. In this schematic, rubber pads 925, 927 and mounting holes 915 for the top and bottom components of the housing are shown, but the top and bottom housings are not illustrated. The design includes liquid flow holes 930 in the PCB 910. Liquid flow holes 930 are present near component 920. For BGA (Ball Grid Array) coupled integrated circuits (as shown), additional inter-chip liquid flow holes 935 are present below the BGA chip among the solder balls of the ball grid array. This provides improved cooling, where transferred liquid contacts not only the top of chip 920 but also the bottom of the chip through the inter-chip liquid flow holes 935. Although only a single chip is illustrated, those skilled in the art will understand that this configuration may include multiple chips, with inter-chip liquid flow holes below some or all of the components on the printed circuit board. One or more of the chips may have inter-chip liquid flow holes 935 below the chip. This configuration utilizes a dual-sided housing. Liquid in contact with the bottom of chip 920 may flow out between the ball interconnect pins or through other liquid flow holes 935.

[0090] Figure 9B It is a semi-transparent side view showing the closed rubber gasket 925, and the external liquid flow hole 930 and in Figure 9A The liquid flow hole 935 between the chips below the BGA chip.

[0091] Figure 9C This is a simplified schematic diagram of the design. The printed circuit board 910 has a double-sided housing 940 surrounding the BGA chip 920. The BGA chip 920 has multiple solder balls 950 that provide connections between the BGA chip 920 and the printed circuit board 910. The solder balls 950 are arranged in a pattern, for example... Figure 9B The pattern shown.

[0092] The printed circuit board has an inter-chip flow via 935 below the chip 920, which allows a liquid flow 970 formed in a liquid chamber 955 between the top and bottom of the dual-sided housing 940 to pass through the PCB 910. In one embodiment, the liquid flow 970 may be upward or downward depending on the orientation of the system. In various embodiments, the liquid within the dual-sided housing 940 moves in a pattern such that the liquid passes through the thermal assembly 920 to absorb heat, and external cooling fins / ribs 960 dissipate heat to the outside of the housing 940. In one embodiment, in addition to the illustrated inter-chip liquid flow via 935, additional liquid flow vias located outside the component area of ​​the PCB may also exist, such as... Figure 9B As shown.

[0093] Figure 9D An embodiment of a dual-sided housing with in-chip liquid flow holes and inter-chip liquid flow holes is illustrated. In addition to the flow holes in the PCB 910 below component 920 (i.e., inter-chip flow holes 935), this configuration also has in-chip flow holes 970 passing through the chip package 920. In one embodiment, the transfer liquid flows through the chip package via the in-chip liquid flow holes 970, improving cooling of the interior of the chip package 920 and bringing the transfer liquid closer to the actual heat-generating die. This configuration requires a redesign of the chip package 920 to include the in-chip flow holes 970. For the in-chip liquid flow holes via the overmolded molding compound, the liquid flow holes can be unplated because the overmolded molding compound is non-conductive and therefore plating these liquid flow holes does not provide a cooling advantage.

[0094] Figure 9E This is a top view of the design, showing all three types of liquid flow holes. External liquid flow holes 930 in the PCB allow liquid to pass between the two sides of the PCB for use in a dual-sided housing. Inter-chip liquid flow holes 935 are holes in the PCB below the chip package. Inter-chip liquid flow holes 935 are positioned such that they are located in locations where there are no solder ball contacts for the chip 920. In-chip liquid flow holes 970 are holes in the chip package 920 rather than in the PCB, allowing liquid to be diverted closer to the die within the chip package 920 for improved cooling. The illustrated closed-loop liquid cooling system may include one or more of these types of liquid flow holes. Thus, a single system may include external liquid flow holes in the PCB, inter-chip liquid flow holes below the component, and / or in-chip liquid flow holes in the component package. For example, in a single-sided housing, there may be no external liquid flow hole 930.

[0095] Figure 9FThis is an X-ray of a typical BGA chip, showing the solder balls and in-chip vias 970. These in-chip liquid flow holes allow liquid to enter the chip package. This allows the liquid to flow through portions of the chip package. However, in this configuration, the transferred liquid does not come into direct contact with the die, but rather flows through the outer portion of the package to increase heat transfer. In another configuration, as shown in the figure below, the transferred liquid flows through the chip package and comes into direct contact with the die.

[0096] Figure 9G An example of in-chip cooling is illustrated, where liquid flow holes do not penetrate the integrated circuit overlay molding. In this configuration, the chip package 920 includes a die 980 attached to an IC (integrated circuit) substrate 990 via epoxy resin 982 and bonding wires 984, a via 986 penetrating the IC substrate, and solder balls 992 on the bottom of the IC substrate 990. The substrate 990 includes the via 986. A portion of the IC substrate 990 is covered by the overlay molding 996, which may be epoxy resin, resin, ceramic, or another material. In-chip liquid flow holes 970 penetrate the IC substrate 990. The liquid flow holes 970 are plated 994 to increase thermal conductivity. This plating 994 contacts the internal metal layer of the IC substrate 990. However, the in-chip flow holes do not penetrate the overlay molding 996.

[0097] Figures 10A-10C This is a schematic diagram of various embodiments of in-chip cooling using a liquid cooling system. Figure 10A Example: Chip package 1005 includes in-chip vias 1010 for liquid cooling. The vias 1010 extend through a portion of an overmolding, which is an epoxy, plastic, or resin cap on the outside of the chip package 1005. Some or all of the vias 1010 may be plated to increase thermal conductivity to the substrate. In some configurations, portions of the in-chip liquid vias within the overmolding are not plated, while portions 1015 of the in-chip liquid vias extending through the IC substrate 1040 are plated. Typically, the chip package 1005 also includes a die 1020, bonding wires 1030, vias 1035, and solder balls 1045. The in-chip vias 1010 are positioned not to interfere with any of these components. The liquid from the die 1020 is transferred through the epoxy resin 1025, and in part through the bonding wires 1030, solder balls 1045, and the die package itself, and through the metal layer in the substrate 1040, to the liquid flowing through the in-chip vias 1010. Note that, although not shown, the chip package 1005 forms a chamber on the PCB enclosed within the housing to contain the transfer liquid.

[0098] Figure 10BA similar configuration is illustrated for a wire-bonded ball grid array chip, where the die 1050 is coupled to the substrate 1040 via solder bumps 1055. The configuration of the in-chip vias 1010 remains the same. In-chip vias can also be used in other types of component packages and are independent of package format.

[0099] Figure 10C An example configuration for in-chip cooling is shown, in which the transfer liquid contacts the die 1060. The die 1060 is coupled to the substrate 1040 via solder bumps 1065. An in-chip flow via 1070 for liquid cooling leads to the center of the package 1005, allowing the liquid 1075 to directly contact the die 1060 and the interior of the package 1005. A plating layer 1015 may be applied to the exterior of the substrate 1040 to increase thermal conductivity.

[0100] Figure 10D This illustration illustrates in-chip cooling in a system comprising chiplets within an integrated circuit package. In this configuration, multiple chiplets 1080 are contained within the integrated circuit package 1005 and coupled to a substrate 1040 via solder bumps 1085. While this configuration illustrates a direct contact configuration where the liquid is in direct contact with the die(s), those skilled in the art will understand that... Figure 10A and 10B The configuration shown (where the flow holes contain transfer liquid and the transfer liquid does not directly contact the (multiple) die) can be used with chiplet 1080.

[0101] Figure 11A-11B This is a schematic diagram of a flip-chip type packaging with liquid flow holes. Figure 11A The figure shows a top isometric view 1110, a top view 1120, a bottom isometric view 1145, and a side view 1115 of a flip-chip package with a plastic overlay molding 1130. The flip-chip package includes solder balls 1140 and a plastic overlay molding 1130 covering one or more small chips or dies 1150. Liquid flow holes 1185 within the chip pass through a portion of the substrate of the chip package, as shown. Figure 11B The same flip chip, without a plastic overlay molding, is shown, illustrating die bonding 1155 and traces 1175 to the substrate. Pads 1160 on the die and 1165 on the substrate are also shown. The pads connect the die 1150 to the substrate via wire bonding 1170 and vias 1180. In this example, liquid flow vias 1185 are located on the outer periphery of the flip chip. Figure 10A-11B Examples of chips with various contact types and configurations are shown. This system is independent of chip type and can be used with the illustrated contact types and chip packages, or with any other contact or chip package that can be modified to include the described internal vias.

[0102] Figure 12 This is a schematic diagram of a cross-section of the chip, showing a liquid flow hole connected to an inner plane of the PCB. The liquid flow hole 1220 contacts an inner plane 1215 of the PCB 1210. The inner plane 1215 of the PCB is typically a copper layer, providing a ground plane for the PCB 1210. Heat transfer from the inner plane of the PCB to the transfer liquid flowing within the flow hole 1220 is increased by using a plating layer 1230 on the edge of the liquid flow hole 1220. This schematic diagram helps to understand the connection of external liquid flow holes to the PCB and the in-chip liquid flow holes through the IC substrate.

[0103] Figures 13A-13C This is a schematic diagram of a system including a liquid actuator. The transfer liquid moves through the housing because it becomes less dense and rises when heated, and falls as it cools by contacting the housing. However, in various embodiments, such as Figures 13A-13C As illustrated, a liquid actuator 1360 is added within a housing. The housing is not shown in the diagram, but its location is indicated by a pad 1320 on the PCB 1310. A liquid through-hole 1340 may be present within the housing. The liquid actuator 1360 can be, for example, an integrated micropump configured to actively circulate and transfer liquid within the housing, a vibrating motor within the housing for generating mechanical stirring, a small immersion fan or propeller, a thermoelectric cooler (TEC) within the housing for generating a temperature gradient (facilitating fluid movement through thermal circulation), a speaker for generating sound waves, and a piezoelectric buzzer for generating ultrasonic vibrations (facilitating the movement of the transferred liquid). Such a liquid actuator can be used with all configurations of the housing (single-sided or double-sided) and all configurations of the flow orifice.

[0104] The liquid actuator 1360 can be continuously turned on to continuously move and transfer liquid, or the system can turn the liquid actuator on and off as needed. The system may include a thermal sensor and a controller 1350 for the liquid actuator 1360. The thermal sensor and controller 1350 may be one or more chips within a housing that provide temperature sensing and control of the operation of the liquid actuator 1360. In this embodiment, the controller 1350 may turn on the liquid actuator 1360 when the temperature is above a threshold. By using the sensor and controller 1350, the system can adjust the speed and direction of the motor to control the flow rate and pattern of the transferred liquid, and reduce the power consumption of the liquid actuator 1360 when not needed or when reducing the rate is sufficient. Figure 13A Example fan motor, which can be used as a liquid drive.

[0105] Figure 13BAn example of a vibration motor that can be used as a liquid actuator is shown. These types of motors are commonly used in a variety of applications to provide haptic feedback, such as in mobile phones, game controllers, and other handheld devices. The vibration motor 1370 includes a housing / shell, an eccentric weight, a motor shaft, a commutator and brushes, windings / coils, and mounting pins / leads. The housing / shell is an external cylindrical structure that protects the internal components of the motor. It is typically made of metal or durable plastic to provide structural integrity and protection. Inside the housing, an eccentric weight (typically an eccentric counterweight) is attached to the motor shaft. When the motor rotates, this weight creates an imbalance, resulting in vibration. The motor shaft is a rotating shaft connected to the eccentric weight. The rotation of the shaft is the cause of the vibration. Inside the motor, the commutator and brushes facilitate the flow of current through the windings, causing the motor to rotate. The motor includes windings / coils that generate a magnetic field when current flows through them. The interaction between this magnetic field and permanent magnets within the motor produces rotation. Alternatively, a non-magnetic actuator known in the art can be used. Mounting pins / leads extend from the motor housing and are used to secure the motor to a PCB and provide electrical connections.

[0106] When the motor 1370 is powered via mounting pins / leads, current flows into the windings. The current through the windings generates a magnetic field, which interacts with the permanent magnets inside the motor, causing the shaft to rotate. As the motor shaft rotates, the eccentric weight generates centrifugal force due to its off-center position. This force produces vibration. This vibration is transmitted through the motor housing to the PCB and then to the device mounting the motor, providing movement for the transferred fluid and increasing the circulation speed.

[0107] Figure 13C An example of a propeller motor is shown, which can be used as a liquid actuator in this system. The propeller motor is similar to the vibratory motor described above, but instead of using an eccentric weight to generate vibration, it attaches a propeller 1365 to a shaft. A fan motor 1360 can be coupled to the PCB via mounting pin 1380. This configuration is designed to generate liquid flow, improving the system's cooling efficiency. The propeller can be configured to generate one of two types of liquid flow: unidirectional flow of transferred liquid and multidirectional flow of transferred liquid.

[0108] In one configuration, the system includes a housing / enclosure, a propeller, a motor shaft, a commutator and brushes, windings / coils, and mounting pins / leads. The housing protects the internal components and provides structural mounting for the PCB. It ensures the durability and integrity of the motor. The motor shaft is connected to the motor. The propeller is attached to the motor shaft—it is responsible for increasing the flow rate of the liquid within the cooling chamber. The blade design ensures efficient movement of the transferred liquid.

[0109] Inside the motor, commutators and brushes facilitate the flow of current through the windings, causing the motor to rotate. As current flows through the windings / coils, they generate a magnetic field that interacts with the permanent magnets inside the motor, thus producing rotation. Mounting pins secure the motor to the PCB and provide electrical connections to power the motor.

[0110] When power is supplied to the motor via mounting pins / leads, current flows into the windings. This current generates a magnetic field in the windings, which interacts with the permanent magnets within the motor, causing the motor shaft to rotate. This rotation of the motor shaft drives the propeller, creating a fluid flow within the chamber. The increased fluid velocity generated by the propeller helps to distribute heat more evenly within the chamber, improving overall cooling efficiency. This significantly improves the performance and reliability of electronic components by maintaining a more uniform temperature across the entire surface of the cooled assembly.

[0111] In another embodiment, different types of motors can be used as part of the liquid actuator. The motor may not include permanent magnets and may be an induction motor, wound rotor motor, synchronous reluctance motor, electrostatic motor, or a type of motor using piezoelectric elements.

[0112] Liquid actuators can be adapted to cooling chambers of different sizes and configurations, making them versatile for a wide range of applications. The use of propeller motors within the housing of liquid cooling systems represents a significant advancement in maintaining optimal operating temperatures for high-performance electronic components.

[0113] Figures 14A-14C This is a schematic diagram of a liquid cooling system configuration that provides electrical isolation. In this configuration, the system's metal casing acts as an effective shield against radiated electromagnetic interference (EMI) and radio frequency interference (RFI). In environments where high-performance electronic components operate, internally generated or externally received electromagnetic noise can significantly impact the performance and reliability of sensitive circuits. EMI and RFI are common problems in modern electronic systems, especially those operating in high-density environments such as data centers, telecommunications systems, and industrial applications.

[0114] The metal enclosure 1410 in the system forms a natural Faraday cage around the enclosed components. A Faraday cage is a structure made of conductive material that blocks electromagnetic fields by redistributing charges on its exterior, thus preventing interference from propagating through the enclosure. In this configuration, the metal enclosure provides a dual function: it protects the internal components from external electromagnetic interference and prevents any radiation / emissions generated within the system from affecting nearby sensitive equipment.

[0115] The continuous conductive surfaces and grounding points of the metal enclosure enable it to effectively mitigate EMI and RFI across a wide frequency spectrum. By containing both electrical and magnetic interference, the enclosure ensures that electronic components function optimally in environments where signal integrity is critical. This shielding effect is particularly useful in applications requiring precise and low-noise operation, such as in telecommunications systems, medical devices, and aerospace avionics.

[0116] Furthermore, the synergistic integration of thermal management and EMI / RFI shielding capabilities adds another layer of reliability to the entire system. The metal enclosure, through advanced surface treatments and structural design, ensures efficient heat dissipation while maintaining signal integrity and reducing the sensitivity of enclosed components to external interference. This results in a highly robust system that not only performs well in terms of thermal performance but also meets stringent electromagnetic compatibility (EMC) requirements. As mentioned above, gasket 1460 is used to ensure the enclosure is leak-proof.

[0117] By featuring EMI / RFI shielding as a system feature, the closed-loop liquid cooling system offers a comprehensive solution that improves both the thermal and electrical reliability of high-performance electronic equipment. This dual functionality further enhances the system's advantages across a wide range of industries where thermal management and electromagnetic shielding are paramount considerations.

[0118] For shielding, the housing is coupled to ground. This coupling may run along the inner edge of the housing. In various embodiments, the ground plane of the PCB may be used for this coupling. In various embodiments, grounding uses aluminum (or other metal) fingers 1420 along the inner edge of the housing 1410. These metal fingers cooperate with copper traces on the PCB to provide shielding for the electronic equipment within the cavity.

[0119] In various embodiments, exposed traces 1435 are used on the PCB 1430 following the inner silkscreen layer 1440. Trace 1435 is stitched between the top and bottom ground traces using frequently spaced stitched vias 1445, thus forming additional shielding for the electronic equipment within the cavity, protecting against radiation, EMI, RFI, and electrostatic discharge (ESD) pulses. These features also reduce electromagnetic noise leaking from within the PCB dielectric. This enables the use of cavitary components in sensitive environments, where radiation leakage is a concern, and in high-radiation environments.

[0120] Figure 15 This is a flowchart illustrating the design of a liquid cooling system using Electronic Design Automation (EDA) tools. Integrating closed-loop liquid cooling technology into electronic products can significantly improve their thermal management capabilities. Using advanced EDA tools allows designers to seamlessly integrate closed-loop liquid cooling features into their designs, simulate thermal performance, and optimize production. Figure 15This provides a typical workflow for this design. The process begins with block 1510. A typical PCB design process begins after the schematic is completed, and components are exported to the design software. The software imports all components, initially placing them in rows and columns outside the PCB outline. The designer then defines the PCB outline and begins placing components in the desired layout. EDA tools typically include automatic placement features that optimize component placement for routing efficiency, taking into account clock / interference / thermal energy dissipation. Adding integrated enclosed liquid cooling design capabilities can provide automatic placement preferences based on the location of the enclosure used for heat dissipation and the size and location of the liquid flow orifices. This process begins after the initial layout of the circuit components on the PCB.

[0121] In block 1515, components are grouped within the schematic design package to form one or more clusters that will be covered by a housing. These clusters are referred to as liquid-cooled clusters (LCCs). This can be done by the designer or automatically based on component identification and their expected thermal requirements. In the PCB design software, these groups are selected and assigned to LCCs, allowing for configuration and optimization. In various embodiments, a single printed circuit board may include multiple LCCs.

[0122] At block 1520, specific configuration data for each LCC is received, which may include one or more of the following: housing placement, chamber size, gasket selection, geometry preferences, mounting hole positioning, liquid flow orifice location and size, and shielding. Configuration data may be input by the designer. Some configuration data may be automatically generated based on anticipated usage configuration data. For example, usage configuration data may include the chip within the chamber, anticipated heat generation, anticipated location of the final product, and use case. The system can then generate chamber configuration data based on the usage configuration data. For example, the chamber volume may be selected based on the component configuration and the component's cooling requirements. The amount of liquid in the system, and therefore the size of the housing, depends on the component's cooling requirements.

[0123] The enclosure placement defines the option to place the liquid chamber on the top, bottom, or sides of the PCB. Enclosure dimensions define the maximum height, material thickness, and geometric cooling features (such as ribs, studs). Gasket options allow selection from standard or custom gasket sizes based on design requirements. Enclosure geometry preferences allow selection of rectangles, squares, the number of corners, and symmetry requirements for cost efficiency in mass production. Mounting holes specify the number, spacing, and location of mounting holes to ensure stability. Liquid flow orifices specify the number, location, and size of flow orifices. Liquid flow orifices can also specify plating for heat conduction paths and power plane connections. Optional EMI / RFI shielding provides specifications for stitching vias around the enclosure perimeter, including spacing and plane connections.

[0124] In block 1530, the housing design is created based on LCC and configuration data. Designers can manually draw the chamber outline or use automated features to ensure the chamber encloses all selected components.

[0125] In block 1535, the automatic placement tool optimizes component position and sides for connectivity and height constraints. Once the component is placed, designers can make manual adjustments and corrections.

[0126] In block 1540, the LC module calculates the retention area based on chamber specifications to prevent interference with the seal and ensure leak-free operation. This data is provided to EDA tools for wiring and clock design.

[0127] After routing, place liquid flow holes at block 1545. Depending on the requirements, liquid flow holes can be placed outside the component area on the PCB, below the component (between chips), or through the component package (inside the chip) at any of the aforementioned locations.

[0128] In block 1550, the system performs simulation-based analysis of the LCC's performance metrics. Simulation parameters may include chamber specifications (thickness, material type, coating, and texture), expected environmental conditions (ambient temperature, airflow, and external influences), component power distribution (power consumption curves and heat generation at various temperatures), and transfer liquid characteristics (density, heat capacity, and type of transfer liquid used).

[0129] In block 1555, the tool can optionally calculate outputs such as steady-state temperature, heat rise curves, chamber volume and weight, and detailed geometry. Then, in block 1560, the designer can fine-tune the details and iterate as needed.

[0130] Once the design is complete, the final design is exported at block 1565. The final design can be manufactured using a G-CODE format compatible with STL, STEP, GES, or CNC. The process then ends at block 1570.

[0131] Using EDA tools for the design and simulation of closed-loop liquid cooling systems offers numerous advantages, including efficiency, optimization, robustness, cost savings, performance, and integration with existing workflows.

[0132] Rapid prototyping and iterative design with real-time feedback offer increased efficiency. The ability to test various configurations and parameters to achieve optimal thermal performance provides optimization. Enhanced thermal management increases the robustness of electronics due to improved reliability and durability. Reduced development time and improved manufacturability result in lower production costs. Improved energy efficiency and extended lifespan of electronic components improve performance due to effective heat dissipation. By leveraging EDA tools, designers can more effectively integrate closed-loop liquid cooling technologies into their products, ensuring electronic devices meet the demanding thermal requirements of modern applications.

[0133] As described above, closed-loop liquid cooling systems utilize leak-proof chambers and one or more types of liquid flow orifices to allow for more efficient heat transfer from one or more components using a transfer liquid. This has numerous uses and advantages and can be used to improve key metrics of computing systems.

[0134] With advancements in semiconductor technology, the demand for improved computing efficiency and density is growing in parallel. Two key metrics—computing / watt efficiency and computing density—are critical performance indicators (KPIs) in computing system evaluation, especially in applications where energy consumption, space constraints, and operating costs are paramount considerations. As silicon-based systems evolve, power density challenges have become a critical factor influencing these two KPIs, necessitating more sophisticated thermal management solutions.

[0135] Computational / watt efficiency refers to the amount of computational work that can be performed per watt of power consumption in a system, typically measured in floating-point operations per watt per second (FLOPS). This metric is essential in a variety of situations, including:

[0136] ● Energy Management: As power consumption continues to be a significant cost driver in data centers and high-performance computing environments, systems with high compute / watt efficiency result in reduced energy consumption for a given compute workload.

[0137] ●Environmental impact: Reducing the power consumption of computing systems directly mitigates the carbon footprint associated with data centers and other energy-intensive operations, contributing to global sustainable development efforts.

[0138] ● Thermal Management: The efficient use of electricity translates into reduced heat output, minimizing the need for extensive cooling infrastructure and extending equipment lifespan by reducing thermal stress.

[0139] ● Battery usage: In portable or remote computing systems that rely on battery power, maximizing computing / watt efficiency is crucial for extending operating life while maintaining performance.

[0140] Computation density measures the available computing power in a given physical space, typically expressed as FLOPS per cubic meter or per rack unit in a data center. This KPI is particularly important in space-constrained or costly environments. Computation density is used to improve:

[0141] ● Space optimization: High computing density is crucial in facilities with limited physical space, such as edge computing nodes or urban data centers, enabling greater computing power to be achieved in a smaller space.

[0142] ● Cost efficiency: Increasing computing density reduces the need for additional physical infrastructure, such as expanded data center space or cooling systems, thereby reducing capital and operating expenditures.

[0143] ● Scalability: Systems with higher computing density allow for more scalable computing growth without a corresponding increase in physical space requirements, thus enabling efficient capacity planning.

[0144] ●Maximize performance: Optimize the use of computing resources to enable organizations to deploy more powerful, higher-performance systems, resulting in increased computing throughput and efficiency.

[0145] With advancements in semiconductor manufacturing processes, transistors and other components are being increasingly densely packed onto silicon chips, leading to a corresponding increase in power density. This presents several challenges:

[0146] ● Heat generation: As power density increases, the heat generated in a smaller surface area increases, making effective heat dissipation more challenging.

[0147] ● Thermal management complexity: Effective management of the thermal load on high-density silicon dies requires advanced cooling solutions to prevent thermal throttling, reduced system efficiency, and potential hardware failures.

[0148] This challenge is a key consideration across various use cases because it directly impacts compute / watt efficiency and compute density. For example, in data centers, high-density silicon designs lead to increased heat output, requiring sophisticated cooling solutions to maintain efficiency. The power density challenge underscores the necessity of improved thermal management to avoid energy waste in cooling systems. The increasing compute density in data centers presents significant thermal management challenges due to the difficulty in dissipating heat from densely packed components. Advanced cooling technologies, such as the closed-loop liquid cooling systems described in this application, can be used to overcome these limitations.

[0149] Edge devices, typically deployed in environments without dedicated cooling infrastructure, must effectively manage heat to maintain operational efficiency. The power density challenge is particularly acute for edge devices, as compact, high-density components generate significant heat within a limited space. Furthermore, achieving high computing density in physically confined edge environments requires compact, high-density silicon chips. This power density challenge for edge devices underscores the need for improved passive or active cooling methods to prevent overheating, such as the closed-loop liquid cooling system described in this paper.

[0150] AI workloads place high demands on GPUs and accelerators, which face challenges in terms of power density. Effective thermal management of these high-density components is crucial for maintaining efficiency and avoiding thermal throttling. AI clusters require high computational density to support multiple graphics processing units (GPUs) within a single chassis or rack. To maintain high-density AI computing without compromising performance, advanced cooling technologies, such as the closed-loop liquid cooling system described in this article, are needed to mitigate the thermal impact of power density challenges.

[0151] Gaming systems utilize high-density silicon chips, particularly in GPUs and CPUs, where the challenge of power density exacerbates the difficulty of heat dissipation. Custom cooling solutions are typically employed to maintain efficiency and performance. As gaming systems push higher power outputs in increasingly compact designs, the power density challenge necessitates effective thermal management to ensure high performance without overheating, such as closed-loop liquid cooling systems.

[0152] In automotive and aerospace systems, compact, high-density silicon designs must operate in harsh environments where power density challenges are critical. Effective thermal management is essential to maintain system reliability and performance. Aerospace applications, in particular, require lightweight, compact systems within space and weight constraints. Innovative cooling solutions, such as closed-loop liquid cooling systems, are needed to meet power density challenges and maintain high computing density in mission-critical environments.

[0153] Therefore, as silicon grains become denser, components shrink, and more computationally intensive processes are used, power density challenges are becoming increasingly prominent across various sectors. This challenge impacts compute / watt efficiency and compute density across industries, including data centers, edge computing, AI workloads, gaming systems, and automotive and aerospace applications. By addressing the thermal management challenges of high-density silicon designs utilizing the aforementioned closed-loop liquid cooling systems, organizations can optimize system performance, reduce energy consumption, and prevent the adverse effects of overheating.

[0154] Figure 16 This is a block diagram of a specific machine that can be used with the present invention. The computing system described herein can be used to provide the electronic design automation (EDA) tools described above. Furthermore, a closed-loop liquid cooling system can be used in such a computing system for cooling one or more components. However, it will be apparent to those skilled in the art that other alternative systems with various system architectures are also possible.

[0155] Figure 16The data processing system shown includes a bus or other internal communication device 1640 for communicating information, and a processing unit 1610 coupled to the bus 1640 for processing information. The processing unit 1610 may be a central processing unit (CPU), a digital signal processor (DSP), or another type of processing unit 1610. Alternatively, the system may include a graphics processing unit (GPU) or other processing system.

[0156] The system may further include random access memory (RAM) or other volatile storage device 1620 (referred to as memory) coupled to bus 1640 for storing information and instructions to be executed by processor 1610. Main memory 1620 may also be used to store temporary variables or other intermediate information during instruction execution by processing unit 1610.

[0157] The system may also include a read-only memory (ROM) 1650 and / or a static storage device 1650 coupled to the bus 1640 for storing static information and instructions for the processor 1610. The system may also include a data storage device 1630, such as a magnetic disk or optical disk and its corresponding disk drive, or flash memory or other memory capable of storing data when the system is not powered. The data storage device 1630 is coupled to the bus 1640 for storing information and instructions.

[0158] The system can be further coupled to an output device 1670, such as a cathode ray tube (CRT) or a liquid crystal display (LCD) via bus 1660 to bus 1640 for outputting information. The output device 1670 can be a visual output device, an audio output device, and / or a tactile output device (e.g., vibration).

[0159] Input device 1675 may be coupled to bus 1660. Input device 1675 may be an alphanumeric input device, such as a keyboard including alphanumeric and other keys, for enabling a user to convey information and command selections to processing unit 1610. Additional user input device 1680 may also be included. One such user input device 1680 is a cursor control device 1680, such as a mouse, trackball, stylus, cursor arrow keys, or touchscreen, which may be coupled to bus 1640 via bus 1660 for conveying directional information and command selections to processing unit 1610 and for controlling movement on display device 1670.

[0160] Another device that may optionally be coupled to computer system 1600 is a network device 1685 for accessing other nodes of the distributed system via a network. Communication device 1685 may include any of many commercial network peripherals, such as those for coupling to Ethernet, Token Ring, the Internet or a wide area network, a personal area network, a wireless network, or other methods of accessing other devices. Communication device 1685 may further be a modemless connection, or any other mechanism providing connectivity between computer system 1600 and the outside world.

[0161] Notice, Figure 16 Any or all components of this system shown, as well as the associated hardware, can be used in various embodiments of the present invention.

[0162] Those skilled in the art will understand that a particular machine embodying the present invention can be configured in various ways according to a particular implementation. The control logic or software implementing the present invention can be stored in main memory 1620, mass storage device 1630, or other storage media that are locally or remotely accessible to processor 1610.

[0163] It will be apparent to those skilled in the art that the design process described herein can be implemented as software stored in main memory 1620 or read-only memory 1650 and executed by processor 1610. This control logic or software may also reside on an article of manufacture comprising a computer-readable medium having computer-readable program code contained therein, and readable by mass storage device 1630, and used to cause processor 1610 to operate in accordance with the methods and teachings herein.

[0164] The computing system can also be configured as a handheld or portable device comprising a subset of the aforementioned computer hardware components. For example, a handheld device may be configured to include only bus 1640, processor 1610, and memory 1650 and / or 1620. The handheld device may be configured to include a set of buttons or input signal components that a user can use to select from a set of available options. These may be considered input device #1 1675 or input device #2 1680. The handheld device may also be configured to include output device 1670, such as a liquid crystal display (LCD) or a display element matrix, for displaying information to the user of the handheld device. Conventional methods can be used to implement such a handheld device. Based on the disclosure of the invention provided herein, embodiments of the invention for such devices will be readily apparent to those skilled in the art.

[0165] The invention can also be embodied in specialized appliances that include a subset of the aforementioned computer hardware components. For example, an appliance may include a processing unit 1610, a data storage device 1630, a bus 1640, and a memory 1620, and may lack an input / output mechanism or have only basic communication mechanisms, such as a small touchscreen that allows the user to communicate with the device in a basic manner. Generally, the more specialized the purpose of the device, the fewer components are required for its operation. In some devices, communication with the user may be via a touch-based screen or similar mechanism. In various embodiments, the device may not provide any direct input / output signals, but may be configured and accessed via a website or other network-based connection through a network device 1685.

[0166] Those skilled in the art will understand that, depending on the particular implementation, any configuration of a particular machine implemented as a computer system may be used. The control logic or software may be stored on any machine-readable medium that is locally or remotely accessible to the processor 1610. Machine-readable media includes any mechanism for storing information in a machine-readable (e.g., computer-readable) form. For example, machine-readable media include read-only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices, or other storage media that can be used for temporary or permanent data storage. The control logic may be implemented as transmissible data, such as electrical, optical, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.).

[0167] The claims define the subject matter to be protected.

[0168] In addition, the following aspects are provided in this specification.

[0169] A liquid cooling system comprising:

[0170] Printed circuit boards (130, 240);

[0171] Gaskets (115, 230) are located on the top side of the printed circuit board (130, 240) and surround one or more components (105) mounted on the printed circuit board (130, 240).

[0172] The housing (220, 260, 810) is located on the gasket and is secured against the printed circuit board to form a sealed chamber together with the printed circuit board (130, 240) and the gasket (115, 230);

[0173] Transfer liquid (838) into the sealed chamber and into contact with one or more components (105) mounted on the printed circuit board (130, 240).

[0174] The liquid cooling system, wherein the housing comprises:

[0175] A first component (220) is located on the top side of the printed circuit board, with the first side resting on the pad; and

[0176] The second component (260) is located on the bottom side of the printed circuit board, with the second side situated on the second pad.

[0177] The liquid cooling system further includes:

[0178] One or more liquid flow holes (110, 840, 935) are sized within the printed circuit board to allow the transfer liquid to circulate between the top and bottom sides of the printed circuit board. The liquid cooling system includes one or more additional components on the printed circuit board outside the housing.

[0179] The liquid cooling system includes one or more additional components, including input / output (I / O) components.

[0180] The liquid cooling system further includes:

[0181] The housing includes a first compartment (520) and a second compartment (525), the first compartment being surrounded by the gasket to provide a sealed housing, and the second compartment being non-leak-proof.

[0182] The liquid cooling system contains a two-phase liquid, which exists as both a liquid phase and a gas phase in the chamber.

[0183] The liquid cooling system wherein the transfer liquid contains one or more of the following: perfluorinated compounds (PFCs) and perfluorinated carbon.

[0184] The liquid cooling system further includes:

[0185] The silkscreen pattern (350, 360) is used to position the pad on the printed circuit board;

[0186] The gasket (315) is placed on the silkscreen pattern, wherein the silkscreen pattern provides positioning and sealing for the gasket, or wherein the silkscreen pattern is on one or both sides of the gasket and the gasket contacts the printed circuit board, without the silkscreen pattern being located between the gasket and the printed circuit board.

[0187] The liquid cooling system, wherein the component includes an integrated circuit having a component package and contacts, the system further includes:

[0188] Inter-chip liquid flow holes (935) are provided in the printed circuit board below the integrated circuit to allow the transfer liquid to pass through the printed circuit board to the volume below the integrated circuit.

[0189] The liquid cooling system, wherein the component includes an integrated circuit having a die within the component package and contacts, the system further includes:

[0190] A closed liquid passage in the component package is configured to allow the transfer liquid to pass through the component package and remove heat from the grain.

[0191] The liquid cooling system further includes:

[0192] A liquid via within the chip, which enters the package of one or more components on the printed circuit board.

[0193] The liquid cooling system, wherein the liquid via in the chip passes through one or more of the following: an integrated circuit substrate, an integrated circuit overlay molding.

[0194] The liquid cooling system includes a first portion of the inter-chip liquid via penetrating the integrated circuit substrate, plated in the liquid cooling system. The liquid cooling system also includes a second portion of the intra-chip liquid via penetrating the overmolded component, not plated in the liquid cooling system.

[0195] The liquid cooling system of claim 10, wherein the transfer liquid replaces one or more thermal ground connections of the integrated circuit.

[0196] The liquid cooling system further includes:

[0197] An active liquid actuator, configured to facilitate the movement of the transfer liquid within the housing;

[0198] The liquid actuator may optionally be one or more of the following: an integrated micro pump configured to actively circulate and transfer liquid within a housing; a vibrating motor within a housing for generating mechanical stirring; a small immersion fan or propeller; a thermoelectric cooler (TEC) within a housing for generating a temperature gradient to promote fluid movement through thermal cycling; a loudspeaker for generating sound waves; and a piezoelectric buzzer for generating ultrasonic vibrations to promote the movement of the transferred liquid.

[0199] The liquid cooling system further includes a control mechanism to adjust the speed and direction of the motor, thereby controlling the flow rate and pattern of the transferred liquid.

[0200] The liquid cooling system, wherein the active liquid driver is mounted on the printed circuit board and positioned to guide the transferred liquid across the subset of components with the highest heat output.

[0201] The liquid cooling system further includes:

[0202] A sensor is used to monitor the temperature of the transferred liquid, and this sensor is coupled to a feedback system to adjust the speed of the liquid drive for optimal cooling performance.

[0203] The liquid cooling system, wherein at least one of the one or more components is contained in a single package containing a small chip having multiple dies.

[0204] The liquid cooling system further includes electronic design automation (EDA) tools integrated to enable the design of the liquid cooling system, the EDA tools placing one or more components on the printed circuit board, the EDA tools further including:

[0205] A user interface that allows the user to define a cluster of one or more components to be included within the shell;

[0206] An automatic positioning tool for designing the housing based on the characteristics and positioning of one or more components.

[0207] The liquid cooling system includes an automated positioning tool designed for the housing, which is further used to calculate the housing's volume, weight, and geometry.

[0208] The liquid cooling system, wherein the automatic positioning tool is further used to identify the gasket specifications of the housing.

[0209] The liquid cooling system further includes:

[0210] An electric motor having a propeller attached to a shaft designed to generate a fluid flow within the housing, thereby enhancing heat distribution from one or more components.

[0211] A method using a closed-loop liquid cooling system, comprising:

[0212] Place the spacer on the printed circuit board, surrounding a portion of the printed circuit board;

[0213] The housing is placed above the gasket and secured against the printed circuit board to form a cavity between the printed circuit boards, the gasket and the housing forming a sealed cavity; and

[0214] The chamber was filled with a transfer fluid.

[0215] The method further includes:

[0216] Multiple liquid flow holes are placed in the printed circuit board so that the transfer liquid can flow through the liquid flow holes between the bottom portion of the housing at the bottom of the printed circuit board and the top portion of the housing at the top of the printed circuit board, wherein the liquid flow holes are optionally inter-chip liquid flow holes below the circuits on the printed circuit board.

[0217] In the foregoing specification, the invention has been described with reference to its specific exemplary configuration. However, it will be apparent that various modifications and alterations can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. Furthermore, the various examples and configurations are generally designed to be mixed and matched, unless they are mutually exclusive. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. A liquid cooling system comprising: Printed circuit boards (130, 240); Gaskets (115, 230) are located on the top side of the printed circuit board (130, 240) and surround one or more components (105) mounted on the printed circuit board (130, 240). The housing (220, 260, 810) is located on the gasket and is secured against the printed circuit board to form a sealed chamber together with the printed circuit board (130, 240) and the gasket (115, 230); Transfer liquid (838) into the sealed chamber and into contact with one or more components (105) mounted on the printed circuit board (130, 240).

2. The liquid cooling system according to claim 1, wherein, The housing contains: A first component (220) is located on the top side of the printed circuit board, with the first side resting on the pad; and The second component (260) is located on the bottom side of the printed circuit board, with the second side situated on the second pad.

3. The liquid cooling system according to claim 2, further comprising: One or more liquid flow holes (110, 840, 935) are sized in the printed circuit board such that the transfer liquid can circulate between the top and bottom sides of the printed circuit board.

4. The liquid cooling system according to any one of claims 1 to 3, wherein, There is one or more additional components on the printed circuit board outside the housing.

5. The liquid cooling system of claim 4, wherein the one or more additional components include input / output (I / O) components.

6. The liquid cooling system according to any one of claims 1-5, further comprising: The housing includes a first compartment (520) and a second compartment (525), the first compartment being surrounded by the gasket to provide a sealed housing, and the second compartment being non-leak-proof.

7. The liquid cooling system according to any one of claims 1-6, wherein the transfer liquid comprises two phases and is both liquid and gas in the chamber.

8. The liquid cooling system of claim 7, wherein the transfer liquid comprises one or more of the following: perfluorinated compounds (PFCs) and perfluorocarbons.

9. The liquid cooling system according to any one of claims 1-8, further comprising: The silkscreen pattern (350, 360) is used to position the pad on the printed circuit board; The gasket (315) is placed on the silkscreen pattern, wherein the silkscreen pattern provides positioning and sealing for the gasket, or wherein the silkscreen pattern is on one or both sides of the gasket and the gasket contacts the printed circuit board, without the silkscreen pattern being located between the gasket and the printed circuit board.

10. The liquid cooling system according to any one of claims 1-9, wherein the component comprises an integrated circuit having a component package and contacts, the system further comprising: Inter-chip liquid flow holes (935) are provided in the printed circuit board below the integrated circuit to allow the transfer liquid to pass through the printed circuit board to the volume below the integrated circuit.

11. The liquid cooling system according to any one of claims 1-10, wherein the component includes an integrated circuit having a die and contacts within a component package, the system further comprising: A closed liquid passage in the component package is configured to allow the transfer liquid to pass through the component package and remove heat from the grain.

12. The liquid cooling system according to any one of claims 1-11, further comprising: An active liquid actuator, configured to facilitate the movement of the transfer liquid within the housing; The liquid actuator may optionally be one or more of the following: an integrated micropump within the housing configured to actively circulate the transferred liquid; a vibrating motor within the housing for generating mechanical stirring; a small immersion fan or propeller; a thermoelectric cooler (TEC) within the housing for generating a temperature gradient to promote fluid movement through thermal cycling; a loudspeaker for generating sound waves; and a piezoelectric buzzer for generating ultrasonic vibrations to promote the movement of the transferred liquid.

13. The liquid cooling system of claim 12, further comprising: An electric motor having a propeller attached to a shaft designed to generate a fluid flow within the housing, thereby enhancing heat distribution from one or more components.

14. A method using a closed-loop liquid cooling system, comprising: Place the spacer on the printed circuit board, surrounding a portion of the printed circuit board; The housing is placed above the gasket and secured against the printed circuit board to form a cavity between the printed circuit board, the gasket, and the housing, forming a sealed cavity; and The chamber was filled with a transfer fluid.

15. The method of claim 14, further comprising: Multiple liquid flow holes are placed in the printed circuit board so that the transfer liquid can flow through the liquid flow holes between the bottom portion of the housing at the bottom of the printed circuit board and the top portion of the housing at the top of the printed circuit board, wherein the liquid flow holes are optionally inter-chip liquid flow holes below the circuit on the printed circuit board.

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