Sealed liquid cooling system

Abstract

Central processing units, integrated circuits, power transistors, voltage regulators, load switches, and other components generate heat during operation. These components must be properly cooled to maintain optimal performance and prevent failure. [Solution] The liquid cooling system comprises a printed circuit board 240, a gasket 230 seated on the upper side of the printed circuit board surrounding one or more components (IC chips) on the printed circuit board, a housing 220 located on the gasket and fastened to the printed circuit board to form a sealing chamber, and a transfer liquid in the sealing chamber that contacts one or more components mounted on the printed circuit board and provides cooling to one or more components.

Description

Technical Field

[0001] This application relates to a thermal management system, and more particularly to a liquid cooling housing integrated with a printed circuit board (PCB) for dissipating heat generated by electronic components.

Background Art

[0002] Integrated circuits (ICs) such as central processing units (CPUs), systems on a chip (SOCs), graphics processors (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, load switches, etc. generate heat during operation. These components must be properly cooled to maintain optimal performance and prevent failures.

[0003] In the prior art, various heat dissipation methods have been used to absorb, remove heat from the IC, and redistribute it away from the hardware.

[0004] Traditionally, cooling methods have relied on a combination of a heatsink and a fan, where air moves across the heatsink to dissipate heat. However, such methods are often insufficient to manage the thermal demands of modern high-performance components.

[0005] One prior-tech solution is liquid cooling. In this system, a liquid, such as water or a special dielectric fluid, circulates to remove heat instead of air. This system generally consists of a base plate connected to the CPU's metal cover via a thermal paste. The base plate forms part of a water block filled with coolant. The coolant absorbs heat from the base plate, is transferred through the water block, and then sent to a radiator. In the radiator, the liquid is exposed to air for cooling, and fans are often used to accelerate heat removal. The coolant then enters the water block again, completing the cycle.

[0006] Semiconductor components exhibit a characteristic known as thermal runaway, where power consumption increases exponentially with rising temperature. As die temperature rises, the power required to perform the same computational operation increases, exacerbating the thermal load. Without efficient heat dissipation, this thermal runaway can escalate, potentially leading to critical temperature levels in semiconductor systems.

[0007] Traditionally, cooling semiconductor dies involves two methods. First, heat dissipation through the upper surface of the die is achieved by a thermal paste bridging the die to a metal heatsink, which is then cooled by air or liquid. Second, grounding pads connected to the package via gold wires linked to a printed circuit board (PCB) are utilized. This allows some heat to be transferred from the die to the PCB via pins or balls. Although relatively inefficient, even these incremental contributions help reduce heat in high-performance systems.

[0008] The combined effect of these conventional cooling methods is consistent with the superposition principle, where any thermal gradient—any junction or material transition with a temperature difference—contributes to reducing the internal temperature of the semiconductor die. Nevertheless, even with state-of-the-art conduction cooling techniques, high-performance semiconductor devices often exhibit internal die temperatures exceeding 100°C in an ambient environment of 30°C.

[0009] To further manage die temperature, many systems incorporate thermal sensors that monitor temperature levels and initiate throttling or other thermal management strategies when approaching a critical threshold.

[0010] Immersion cooling has been used in the electronics industry for many years, but it presents several drawbacks because it requires the entire motherboard or subassembly to be submerged in a liquid tank. In such configurations, interconnects such as wires and cables must be kept out of the liquid, making installation complex and often cumbersome. Additionally, the large amount of liquid required makes the system expensive, and the liquid is easily lost through evaporation, making it difficult to manage. [Brief explanation of the drawing]

[0011] The present invention is illustrated in the accompanying drawings as an example, not as an limitation, and similar reference numerals refer to similar elements. [Figure 1] This is a top view of one exemplary configuration of a liquid cooling system. [Figure 2A] This is an exploded view of one exemplary configuration of a liquid cooling system. [Figure 2B] This is an exploded view of one exemplary configuration of a liquid cooling system. [Figure 2C] This is a diagram of one exemplary configuration of a printed circuit board, including several components and gaskets. [Figure 3A] These are cross-sectional views of different embodiments of the gasket and housing. [Figure 3B] These are cross-sectional views of different embodiments of the gasket and housing. [Figure 3C] These are cross-sectional views of different embodiments of the gasket and housing. [Figure 4] This is a cross-sectional view of one embodiment of a liquid cooling system. [Figure 5A] These are internal diagrams of exemplary versions of the upper and lower parts of the enclosure. [Figure 5B] These are internal diagrams of exemplary versions of the upper and lower parts of the enclosure. [Figure 6A] This is a cross-sectional view of a liquid cooling system having a symmetrical attachment. [Figure 6B] This is an illustrative diagram of a simulation of the movement of the transfer fluid inside the enclosure. [Figure 6C] This is an illustrative diagram of a simulation of heat dissipation within the enclosure. [Figure 7A] This is a front and rear perspective view of the enclosure of one component of a liquid cooling system. [Figure 7B] This is a front and rear perspective view of the enclosure of one component of a liquid cooling system. [Figure 8A] This is an illustrative diagram of a liquid cooling system including a filling valve and conformal coating for a single-sided system. [Figure 8B] This is a flowchart of various embodiments for filling a liquid cooling system. [Figure 9A] This is an illustrative diagram of a cooling system using a liquid cooling system. [Figure 9B] This is an illustrative diagram of a cooling system using a liquid cooling system. [Figure 9C] This is an illustrative diagram of a cooling system using a liquid cooling system. [Figure 9D] This is an illustrative diagram of a cooling system using a liquid cooling system. [Figure 9E] This is an illustrative diagram of a cooling system using a liquid cooling system. [Figure 9F] This is an illustrative diagram of a cooling system using a liquid cooling system. [Figure 9G] This example illustrates in-chip cooling where the liquid flow holes do not penetrate the overmolding of the integrated circuit package. [Figure 10A]An illustrative diagram of an embodiment of in-chip cooling using a liquid cooling system. [Figure 10B] An illustrative diagram of an embodiment of in-chip cooling using a liquid cooling system. [Figure 10C] An illustrative diagram of an embodiment of in-chip cooling using a liquid cooling system. [Figure 10D] Illustrates in-chip cooling for a system that includes dielets within an integrated circuit package. [Figure 11A] An illustrative diagram of a flip-chip type package having liquid flow holes. [Figure 11B] An illustrative diagram of a flip-chip type package having liquid flow holes. [Figure 12] An illustrative diagram of a cross-section of a chip having liquid flow holes connected to the inner surface of a PCB. [Figure 13A] An illustrative diagram of various embodiments of a system including a liquid driver. [Figure 13B] An illustrative diagram of various embodiments of a system including a liquid driver. [Figure 13C] An illustrative diagram of various embodiments of a system including a liquid driver. [Figure 14A] An illustrative diagram of an embodiment of a liquid cooling system that provides electrical insulation. [Figure 14B] An illustrative diagram of an embodiment of a liquid cooling system that provides electrical insulation. [Figure 14C] An illustrative diagram of an embodiment of a liquid cooling system that provides electrical insulation. [Figure 15] A flowchart using an electronic design automation (EDA) tool for designing a liquid cooling system. [Figure 16] A block diagram of a computer system that can be used with the present system.

Best Mode for Carrying Out the Invention

[0012] This invention describes a liquid cooling system including a housing connected to a printed circuit board using a gasket. The housing is filled with a transfer fluid that has a high coefficient of heat transfer but is not conductive (i.e., electrically insulating). The transfer fluid may be a single-phase or two-phase liquid. The system can provide board-level cooling for cooling one or more chips on a printed circuit board. In various embodiments, the system can provide inter-chip cooling, which provides improved cooling by including inter-chip liquid flow holes beneath the components to ensure that the transfer fluid comes into contact with the lower portion of one or more components on the printed circuit board. In some embodiments, the system can provide intra-chip cooling using flow holes through the integrated circuit package to allow the transfer fluid to flow closer to the heat source. Intra-chip cooling allows the transfer fluid to enter the circuit package. In some embodiments, the transfer fluid comes into direct contact with the die within the integrated circuit package. Additionally, the housing can protect the components from radiation.

[0013] The system may be designed using electronic design automation (EDA) tools that can design the housing for the liquid cooling system, as well as its positioning, size, and other configuration details. The EDA tools may be integrated into an existing EDA system and enable the design of a printed circuit board layout that takes the liquid cooling system into account, including liquid flow holes, sealing parts, positioning, and other factors. As used herein, a liquid flow hole is a hole in a printed circuit board or component package into which a transfer fluid can enter.

[0014] This system offers the advantages of immersion cooling but limits the coolant to only a subset of the system. This subset includes components that require thermal management. The system seals the transfer fluid within a sealed system, ensuring that the transfer fluid neither leaks nor evaporates. The transfer fluid should not require replenishment throughout the product's lifespan.

[0015] The sealed liquid cooling system significantly improves the cooling of semiconductor components from the bottom, simultaneously improving heat transfer from below, while replacing the conventional, inefficient methods of top-side cooling.

[0016] In various embodiments, the transfer fluid contacts the underside of the chip, enabling direct liquid cooling of all sides of the die, effectively cooling the pins, balls, and surface area beneath the chip. It also cools the PCB itself. This is achieved by cooling the inner surface of the PCB through strategically placed fluid flow holes, allowing for more uniform heat dissipation throughout the system with a smaller thermal gradient. Furthermore, the positioning of the fluid flow holes provides a path for the transfer fluid to move around the inside of the chamber or housing, and this movement increases heat transfer from the components.

[0017] This method offers a synergistic effect where a decrease in the internal die temperature also reduces power consumption, creating a reverse thermal runaway effect. Reduced power consumption further lowers the temperature (or limits or prevents temperature rise), improving the overall energy efficiency of the system. Therefore, this system offers multiple technical benefits, improved efficiency, and enhanced performance. The system further increases durability, reliability, and stability because its components are kept at more efficient operating temperatures. A system operating at a given performance level operates at lower temperatures, reduces power consumption, and increases overall energy efficiency. A system designed for maximum performance can achieve higher output while consuming less power and maintaining thermal stability.

[0018] As semiconductor die sizes decrease and / or more dies are integrated onto a single chip, power density increases, and therefore, heat generated within a smaller area increases. Sealed liquid cooling systems enable more efficient heat transfer across systems including multiple dies, chips, power delivery components, and the PCB itself, thus improving the overall power consumption, thermal management, and power density of the system.

[0019] In various embodiments, the system includes a thermal sensor for monitoring die temperature. When the die reaches a critical temperature, in some embodiments, performance throttling is initiated to prevent further thermal runaway. The system reduces the workload on the die and stabilizes the temperature at an equilibrium point where maximum allowable performance is maintained without overheating the chip. In other cases, such as during overclocking, 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 that the temperature remains within safe operating limits.

[0020] Furthermore, as the demand for computing power continues to increase, the power consumption of data centers worldwide will also continue to rise. By integrating sealed liquid cooling technology into individual chips and computing nodes within data centers, overall power consumption can be reduced. This reduction in power requirements not only improves the efficiency of individual data centers but also contributes to reducing the global energy footprint required for computing power.

[0021] The following detailed description of the invention is made with reference to the accompanying drawings, where similar reference numerals indicate similar elements and illustrate various embodiments for carrying out the invention. The descriptions of these embodiments are sufficiently detailed to enable those skilled in the art to carry out the invention. Those skilled in the art will understand that various embodiments may be used in alternative configurations and that logical, mechanical, electrical, functional, and other modifications may be made without departing from the scope of the invention. Accordingly, the following detailed description should not be construed as restrictive, and the scope of the invention is defined solely by the appended claims.

[0022] Figure 1 is a top view of one configuration of a liquid cooling system. The liquid cooling system includes a housing, also referred to as a chamber. The housing 100, which is only partially visible in Figure 1, covers a portion of a printed circuit board 130, which includes a heat-generating chip (or component) 105. As described, the housing, together with other components, acts to define a sealed volume that may be referred to as a chamber. The housing is generally mounted using mounting holes 140. The system has a rubber seal or gasket 115, which is used to provide a leak-proof seal between the printed circuit board 130 and the housing, for example, a seal that prevents the transfer fluid from passing through. The gasket is seated on the PCB, although there may not be any seating grooves on the PCB. The housing is seated on the gasket. To facilitate the seating and placement of the gasket on the PCB, seating grooves may be provided on the housing. In various embodiments, outer silkscreen lines 120 and inner silkscreen lines 125 provide seating grooves that define the position of the gasket 115. The silkscreen lines are used to provide positioning for the enclosure and to ensure that the enclosure is leak-proof. The use of silkscreen lines 120, 125 also provides the ability to guide PCB traces 135 under the enclosure and gasket as pass-through PCB traces 137 without creating gaps. The enclosure is filled with a transfer fluid used to transfer heat from component 105 to a heat sink (not shown).

[0023] The transfer fluid flows in a convection pattern, transferring heat from the tip 105 to the metal housing 100, which includes fins for heat dissipation. The liquid flow holes 110 are dispersed in a pattern to optimize heat transfer from the tip to the outside of the housing. A hotter material or gas rises, creating a temperature difference that induces liquid flow within the housing between the heated transfer fluid and the cooler outside of the housing. In various embodiments, the transfer fluid 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 fluid in liquid form. In another embodiment, the transfer fluid can transition between liquid and gas phases at specific locations where it is heated above its boiling point, and then revert back to liquid as it flows into a region where the gas cools below its boiling point. This can increase the convection level because, due to its lower density, the gas rises faster than the heated liquid.

[0024] Perfluorinated compounds (PFCs) and perfluorocarbons can be used as transfer fluids. In one embodiment, Fluorinert® Electronic Liquid from 3M® Corporation can be used as a transfer fluid. An example of such a liquid that can be used is FC-72, which has a boiling point (phase transition point between liquid and gas) of 56 degrees Celsius at atmospheric pressure. This means that when the liquid in the housing is at atmospheric pressure, the semiconductor embedded in this liquid is heated to such an extent that its external surface temperature exceeds this boiling point of 56 degrees Celsius, causing the liquid to boil (convert to gas) around the top, sides, and bottom surfaces of the semiconductor, and then the gas bubbles against gravity, flows away from the chip, cools as it mixes with a cooler liquid, and simultaneously the new, cooler liquid flows over the surface surrounding the chip. At higher pressures, the conversion of the liquid to the gas phase occurs at higher temperatures. Other non-conductive liquids can also be used.

[0025] The enclosure is designed to cover a group of sealed components 150 including one or more heat-generating components 105, and to 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, in the case of a double-sided enclosure, one or more liquid flow holes 110 allow liquid to circulate between the two sides of the printed circuit board.

[0026] The design may include more or fewer excluded components 155, or enclosed components 150. There may be configurations that do not include excluded components, where the enclosure covers one or both sides of the PCB. This configuration may be used, for example, with a PCB that uses a PCI (Peripheral Component Interconnect) express bus. In such a configuration, the PCB is designed to be inserted into a PC motherboard, and since all computational instructions pass through the PCI express bus, the PCB has no external components.

[0027] The system may not include silkscreen lines, or it may include a single line that positions the gasket on top. In a single-sided enclosure, there may be no fluid flow holes because the transfer fluid does not move between the sides of the PCB.

[0028] Figures 2A and 2B are exploded views of an exemplary configuration of a liquid cooling system. The illustrated system provides an exploded front view 200 in Figure 2A and an exploded perspective or isometric view of a double-sided housing in Figure 2B. The system shows a printed circuit board 240 having two rubber gaskets 230, 250 to which the upper 220 and lower 260 of the housing are connected. In various embodiments, screws 270 are used to attach the lower 260 of the chamber to the upper 220 of the chamber through mounting holes in the PCB 240. The screws may be oriented from the top and / or bottom. The screws may be terminated within the housing. The screws may be replaced by rivets or other fasteners. The housings 220 and 260 are fastened to the PCB 240 by being fastened to each other. They are also fastened to the PCB to form a leak-proof housing.

[0029] The enclosure can be made from any high thermal conductivity material. In various embodiments, the enclosure is made from aluminum, graphite, ceramic, and / or aluminum oxynitride. The enclosure can be made from another material that is thermally conductive but not conductive. The enclosures 220, 260 are in contact with the transfer fluid, and heat is transferred from the transfer fluid to the enclosure, where it is dissipated into the space. The upper 220 and / or lower 260 of the enclosure may have fins, pin fins, or other components for better heat dissipation. An optional external fan 210 may also be used. In addition to, or instead of, using fans and airflow to dissipate heat, external liquid cooling may be used. Additional methods for dissipating heat from outside the enclosure may be used.

[0030] The printed circuit board 240 and gasket 230 are shown in detail in Figure 2C, illustrating a perspective view of the printed circuit board showing the precisely positioned gasket. As can be seen, some components are located inside the enclosure. These components are located within the area defined by the gasket. The gasket surrounds these components, i.e., encloses them within the plane of the gasket. As can be seen, some other components are located outside the enclosure (e.g., outside the rubber gasket defining the edge of the enclosure). These other components are used in various embodiments to connect the printed circuit board and its components to other components of the computer system. In addition to, or instead of, I / O (input / output) components, other components on the PCB may also be located outside the enclosure.

[0031] Figures 3A to 3C are cross-sectional views of various embodiments of the gasket and housing. Figure 3A illustrates a housing 310 connected to a printed circuit board 345 using mounting screws 340. Two parallel silkscreens 350 define the position of the gasket or rubber seal 315. The housing 310 includes threaded holes 320 for receiving the mounting screws 340. The gasket 315 and silkscreens 350 are located on top of a solder mask 325, which is superimposed on a copper layer having traces 330 on top of the PCB dielectric 335.

[0032] Figure 3B illustrates a configuration in which a single silkscreen layer 360 is used and the gasket 315 is positioned on top of the single solid silkscreen layer 360. The silkscreen provides positioning guidance and a smooth surface to ensure that the chamber defined by the housing 310 is leak-proof.

[0033] Figure 3C illustrates a configuration in which there is no silkscreen layer and the gasket rests on top of the solder mask 325.

[0034] A gasket provides a seal between the chamber and the printed circuit board, creating a leak-proof seal that prevents the passage of liquid. The seal may be described as leak-proof or watertight, although the required level of sealing may differ depending on the pressure difference of the liquid compared to water, and the liquid is not water. Furthermore, a leak-proof seal also prevents leakage of the liquid in gaseous form. The gasket maintains the seal between components, ensuring consistent and efficient performance under various operating conditions. Gaskets may be made from rubber, silicone, foam, or other sealing materials. In various embodiments, the gasket provides EMI / RFI shielding. This can be achieved using a combination of foam and wire mesh materials, or other materials. Alternatively, the gasket may be made from a conductive material or may have a conductive outer surface to help prevent EMI leakage. In another embodiment, the system may include a first gasket for sealing and a second gasket for electrical signal shielding.

[0035] Figures 3A to 3C illustrate the configuration of a printed circuit board, copper layer, and solder mask, but those skilled in the art will understand that the configuration of these components is not essential to the present invention. Rather, the system includes a housing that forms a chamber enclosing all or part of the printed circuit board, using a gasket to seal the housing against the PCB in a leak-proof manner. The actual configuration of the layers on the PCB is independent of the design, as is the size and position of the components on the PCB.

[0036] Figure 4 is a cross-sectional view of a liquid cooling system having an upper compartment and a lower compartment. The system includes an upper housing 410 connected to a lower housing 420. The housings 410 and 420 are made of aluminum, aluminum alloy, aluminum oxynitride (ALON), or another heat-conducting material.

[0037] The housings 410 and 420 are connected 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 the transfer fluid to circulate between the upper and lower parts of the chamber. The liquid-filled chamber 460 is formed by the upper and lower parts of the housing. The housing components 410 and 420 are connected to the printed circuit board using rubber seals or gaskets 430 and 435 to ensure that the transfer fluid does not leak.

[0038] The shape of the chamber shown is defined by the shape of the sealing components on a printed circuit board (not shown). In this configuration, some parts of the printed circuit board have higher components, while others have lower components. The actual shape of the chamber can be modified to fit the configuration of the components on the printed circuit board.

[0039] In various embodiments, the outer surface of the housing may include fins 470, pin fins, and / or other protrusions to dissipate heat transferred by the transfer fluid filling the chamber. The fins are sized to maximize the cooling area, but are thick enough for manufacturability, stable and non-deformable, and thin enough to further maximize airflow and area. The system may use any configuration of fin or protrusion shapes. One or more optional fans may be positioned above or near the chamber. Other methods of removing heat from the chamber may be used.

[0040] Liquid cooling systems utilize advanced materials and structural reinforcements to maximize the efficiency of heat dissipation from the cooling chamber. In various embodiments, the housing is constructed from aluminum, selected for its thermal conductivity and lightweight properties. In another embodiment, the housing is constructed from aluminum oxynitride, often referred to as ALON®, a transparent ceramic composite material containing aluminum. In one embodiment, the housing is constructed from graphite, ceramic, or a composite material.

[0041] To optimize heat dissipation, the enclosure may have thin walls, cooling ribs or fins, and / or surface treatments to increase its surface area. The enclosure walls may be as thin as 1 mm, providing rapid heat transfer without adding unnecessary weight. The enclosure may be designed to have cooling ribs, pins, and / or fins on its outer surface. These structural features increase the surface area of ​​the enclosure and promote greater heat exchange between the enclosure and the ambient air.

[0042] One or more surface treatments may be applied to the interior or exterior of the enclosure. Examples of surface treatments include sandblasting, powder coating, anodizing, and radioactive coating. The purpose of the surface treatment is to increase heat transfer.

[0043] Sandblasting the aluminum surface can create a rougher texture, increasing the surface area available for heat dissipation. Sandblasting may be applied only to the outer surface of the housing, while the inner surface remains smooth to reduce turbulence in the transfer fluid.

[0044] A heat-resistant powder coating may be applied to the exterior of the enclosure. This coating can be formulated to emit infrared radiation when heated, thereby improving heat transfer by radiating thermal energy into the surrounding air.

[0045] Anodizing aluminum improves its corrosion resistance and enhances its ability to conduct heat. Anodized layers also increase surface durability, particularly in environments with moisture or chemicals. The inner surface of the enclosure can be anodized.

[0046] A special infrared radiation coating may be applied to the exterior of the enclosure. When the enclosure is heated, the coating radiates heat in the form of infrared radiation, further improving overall heat dissipation from the system.

[0047] Other surface treatments may be applied to increase heat transfer through the enclosure.

[0048] By combining structural reinforcements such as cooling ribs and sandblasting with advanced surface treatments such as powder coating or anodizing, the system significantly improves its thermal management capabilities. The inclusion of infrared radiation coatings provides an additional mechanism for heat transfer, utilizing radiation as a means to cool the system more efficiently.

[0049] In addition to these thermal advantages, the system's metal enclosure also improves the mechanical robustness of the PCB substrate and protects the sealed components. The high-strength metal enclosure provides superior protection against physical stresses such as vibration, shock, and external pressure. This added durability not only protects the electronics from physical damage but also increases the product's lifespan in demanding environments. These design choices ensure that the system maximizes heat transfer from the internal fluid to the external environment, as well as contributes to the overall mechanical resilience, energy efficiency, and reliability of high-performance electronics.

[0050] Figures 5A and 5B are internal views of specific configurations of the upper and lower components of the housing. The housing includes a first liquid-filled compartment or chamber, which is a liquid chamber 520. The housing includes a seating groove for a gasket 530 that surrounds the liquid chamber 520. In one embodiment, the housing may also include a second compartment, protective cavity 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, one part of the housing has open screw holes 560, and the other part has threaded screw holes 570 for receiving screws that attach the housing components to each other. In another embodiment, the upper and lower parts of the housing may each have two open screw holes and two threaded screw holes. In some embodiments, the upper and lower parts of the housing are symmetrical.

[0051] Figure 6A is a cross-sectional view of a liquid cooling system showing a symmetrical attachment. In this configuration, one mounting screw 635 is inserted through the upper housing 610, with a threaded hole located in the lower housing, and the other is the other. This configuration allows for the use of symmetrical upper chambers 610 and lower chambers 620. As can be seen, the upper and lower housing components in this cross-section appear identical. However, in some other embodiments, the two parts of the housing may have different shapes to accommodate the configuration of components on the PCB.

[0052] In various embodiments, the system includes one or more liquid flow holes 680 or liquid vias through a printed circuit board 660. The liquid flow holes 680 allow a transfer fluid used to cool the components to circulate around the chamber. The PCB 660 may also include one or more component vias 685. Such component vias 685 are generally plated with metal to allow connection of components.

[0053] Figure 6B is an illustrative diagram of the simulation of liquid flow inside the enclosure and air flow outside. As can be seen, the transfer fluid rises due to the heat from the tip and cools when it reaches the outside of the chamber. The cooled transfer fluid then falls, thereby creating convection illustrated by the lines shown. The transfer fluid used may be a two-phase transfer fluid containing a liquid phase and a gas phase during use. Here, the majority of the transfer fluid is in the liquid phase, and a portion of the transfer fluid is in the vapor / gas phase. The transition from the liquid phase to the gas phase requires energy, and the transition in the opposite direction releases energy. Thus, during operation, the liquid absorbs heat and evaporates it. It then condenses back into a liquid at different locations, effectively transferring heat from one location in the system (specifically, where there are heat-generating components) to another location in the system (specifically, where heat can be transferred from the system to the outside).

[0054] Figure 6C illustrates the high-temperature region of the chip inside the enclosure. As can be seen, as the heated transfer fluid moves away from the heat source (chip), the transfer fluid cools rapidly, and therefore the circulating transfer fluid can be used to cool the chip in the relatively small gap between the top of the chip and the top of the enclosure. This system optimizes the position and size of the liquid flow holes so that the transfer fluid can flow between the top and bottom of the system. Simulations show that 1.5 mm flow holes under the circuit work better than larger holes, as increased flow through smaller holes improves cooling by supplying cooler liquid more quickly. In various embodiments, the liquid flow holes under the chip being cooled are sized between 1 and 3 mm. Liquid flow holes in different locations may be sized differently. Liquid flow holes under the chip may be smaller than liquid flow holes on the PCB around the chip. The maximum size of the liquid flow holes under the chip is defined by the spacing between BGA balls / contacts. The liquid flow holes are designed so as not to interfere with the connection of components to the printed circuit board.

[0055] Figures 7A and 7B are perspective views of one embodiment of the front and rear of an assembled housing of a liquid cooling system. The assembled housing 710 has fins all around its perimeter and provides openings for connectors to other components. In the shown configuration, an integrated fan 720 is present between the fins to increase airflow along the outside of the housing 710.

[0056] Figure 8A is an illustrative diagram of a liquid cooling system including a filling valve and conformal coating for a one-sided system. In this configuration, the housing 810 has only one side, and the opposite side of the PCB is coated with a leak-proof conformal coating 830. Therefore, the liquid 838 circulates only on one side of the printed circuit board 822. In this configuration, the high-temperature components 826 that require cooling are located on one side of the printed circuit board 822. The conformal coating 830 may be epoxy, parylene, silicone-based coating, urethane, acrylic, fluoropolymer, or another material that is leak-proof and can withstand the transfer fluid and the heat level in the chamber. In one embodiment, one or more liquid flow holes 840 may be present within the printed circuit board 822. The liquid flow holes may be plated to provide improved cooling by contacting a metal layer in the PCB.

[0057] In various embodiments, the housing 810 includes a filling valve 842. The filling valve 842 allows for the addition of liquid 838 into the chamber 810. The filling valve 842 includes one or more threaded holes in the housing. Once the liquid has filled the chamber to a specified level, the filling valve is closed by a closing screw 844, a closing bolt, a plug, or another type of fastener to ensure the filling valve 842 is closed. The filling valve may include a one-way valve element that allows the liquid to enter through the valve but prevents the liquid from exiting through the valve.

[0058] Figure 8B is a flowchart of various embodiments for filling a liquid cooling system. The process starts in block 850. In block 855, the process determines whether a filling valve is used. If it is used, the process proceeds to block 880. If a filling valve is not used, the process proceeds to block 860.

[0059] In block 860, the enclosure is partially attached to the printed circuit board, leaving a gap. The screws are partially tightened, but sufficient space is left for the fluid.

[0060] In block 865, the enclosure and PCB are immersed in a transfer fluid tank, and in block 870, the transfer fluid fills the enclosure. The transfer fluid partially fills the enclosure so as to allow the expansion of the two-phase transfer fluid when it turns into a gas. Alternatively, if the transfer fluid is a single-phase fluid that remains liquid for all relevant temperatures and does not expand when heated, the fluid can completely fill the enclosure.

[0061] In block 875, the enclosure is fully mounted, providing a leak-proof seal and sealing the transfer fluid. The enclosure and PCB are then removed from the transfer fluid tank. The process then ends in block 899.

[0062] If, in block 855, the process determines that a filling valve is to be used, the process proceeds to block 880.

[0063] In block 880, the process determines whether the filling valve is open. If it is not open, in block 885, the filling valve is opened. Note that in this configuration, the housing is fully installed before the addition of the liquid. Therefore, the housing is sealed to the printed circuit board in a leak-proof manner.

[0064] In block 890, a filling valve is used to fill the chamber with liquid to the appropriate level. As described above, the filling may be to a level that allows for the expansion of the transfer fluid, including the two-phase transfer fluid, if used.

[0065] In block 895, the filling valve is sealed. The filling valve may be sealed using a screw, a plug, or other component. Filling may also involve changing the pressure level inside the housing. Changing the pressure inside the housing may involve reducing the pressure inside the chamber by using a vacuum pump to remove some or all of the residual air from the chamber. Changing the pressure may further involve adding additional air or another gas that is heavier or lighter than air to increase the pressure inside the chamber. By changing the pressure inside the chamber, the flow pattern of the transfer fluid may be altered. The process then ends in block 899.

[0066] Figures 9A to 9E illustrate various embodiments of cooling using a liquid cooling system. Figure 9A illustrates a configuration having a single BGA chip 920. In this illustration, rubber gaskets 925, 927 for the upper and lower components of the housing are shown, but the upper and lower housings are not illustrated. This design includes a liquid flow hole 930 within the PCB 910. The liquid flow hole 930 is located in close proximity to the component 920. In a BGA (ball grid array) linked integrated circuit (as illustrated), additional inter-chip liquid flow holes 935 are located between the solder balls of the ball grid array beneath the BGA chip. This improves cooling, as the transfer fluid contacts not only the top of the 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 having inter-chip liquid flow holes beneath some or all of the components on the printed circuit board. One or more chips may have inter-chip liquid flow holes 935 beneath the chip. This configuration utilizes a double-sided housing. Liquid in contact with the underside of chip 920 may flow out between ball interconnecting pins or through other liquid flow holes 935.

[0067] Figure 9B is a translucent side view showing the sealing rubber gasket 925 beneath the BGA chip in Figure 9A, as well as the outer fluid flow holes 930 and the inter-chip fluid flow holes 935.

[0068] Figure 9C is a simplified diagram illustrating the design. The printed circuit board 910 has a double-sided housing 940 surrounding the BGA chip 920. The BGA chip 920 has a plurality of 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, the pattern shown in Figure 9B.

[0069] The printed circuit board has inter-chip flow holes 935 beneath the chip 920, which allow a liquid flow 970 through the PCB 910 between the upper and lower parts of the double-sided housing 940. In one embodiment, the liquid flow 970 can rise or fall depending on the orientation of the system. In various embodiments, the liquid within the double-sided housing 940 moves in a pattern, allowing the liquid to pass through the high-temperature components 920 to absorb heat and then pass through the external cooling ribs / fins 960 to release the heat to the outside of the housing 940. In one embodiment, in addition to the illustrated inter-chip liquid flow holes 935, additional liquid flow holes may exist through the PCB outside the area of ​​the components, as shown in Figure 9B.

[0070] Figure 9D illustrates one embodiment of a double-sided enclosure having intra-chip liquid flow holes and inter-chip liquid flow holes. In addition to a flow hole in the PCB 910 below the component 920, which is an inter-chip flow hole 935, this configuration also has an intra-chip flow hole 970 that passes through the chip package 920. In one embodiment, the transfer fluid flows through the chip package through the intra-chip liquid flow hole 970, increasing the cooling effect on the inside of the chip package 920 and bringing the transfer fluid closer to the actual die that generates heat. This configuration requires a redesign of the chip package 920 to include the intra-chip flow hole 970. In the case of intra-chip liquid flow holes that penetrate an overmolding, the liquid flow holes do not need to be plated, as the overmolding is not conductive and therefore plating these liquid flow holes does not provide any cooling benefit.

[0071] Figure 9E is a top view of the design, showing all three types of liquid flow holes. The outer liquid flow hole 930 in the PCB allows the liquid to pass between the two sides of the PCB in the case of a double-sided enclosure. The inter-chip liquid flow hole 935 is a hole in the PCB below the chip package. The inter-chip liquid flow hole 935 is positioned so that there is no contact between the solder balls and the chip 920. The intra-chip liquid flow hole 970 is a hole in the chip package 920, not in the PCB, which allows the transfer fluid to approach the die within the chip package 920 to improve cooling. The described sealed liquid cooling system may include one or more of these types of liquid flow holes. Therefore, a single system may include the outer liquid flow hole in the PCB, the inter-chip liquid flow hole below the component, and / or the intra-chip liquid flow hole within the component package. For example, in a single-sided enclosure, the outer liquid flow hole 930 may not be present.

[0072] Figure 9F is an X-ray of a typical BGA chip, showing solder balls and intrachip fluid flow holes 970. These intrachip fluid flow holes penetrate the chip package, allowing the fluid to enter the package. This allows the transfer fluid to pass through a portion of the chip package. However, in this configuration, the transfer fluid does not directly contact the die, but rather passes through external components of the package to increase heat transfer. In another configuration illustrated below, the transfer fluid flows through the chip package and directly contacts the die.

[0073] Figure 9G illustrates an in-chip cooling configuration in which the liquid flow holes do not penetrate the integrated circuit overmolding. In this configuration, the chip package 920 includes a die 980 mounted on an IC (integrated circuit) substrate 990. A portion of the IC substrate 990 is covered by an overmolding 996, which may be epoxy, resin, ceramic, or another material. The in-chip liquid flow holes 970 penetrate the IC substrate 990. The liquid flow holes 970 are plated 994 to increase thermal conductivity. The plating 994 is in contact with the internal metal layer of the IC substrate 990. However, the in-chip flow holes do not penetrate the overmolding 996.

[0074] Figures 10A to 10C illustrate various embodiments of in-chip cooling using a liquid cooling system. Figure 10A illustrates a chip package 1005 that includes an in-chip flow hole 1010 for liquid cooling. The flow hole 1010 extends through a portion of the overmold, which is an epoxy, plastic, or resin cover on the outside of the chip package 1005. Part or all of the flow hole 1015 may be plated to increase thermal conductivity to the substrate. In some configurations, the portion of the in-chip liquid flow hole within the overmold is not plated, while the portion of the in-chip liquid flow hole that penetrates the IC substrate 1040 is plated 1015. The chip package 1005 also includes a die 1020, coupling wires 1030, and solder balls 1045, as usual. The in-chip flow hole 1010 is positioned so as not to interfere with any of these components. Heat is transferred from the die 1020 through the epoxy 1025 combination, partially through the bonding wires 1030, solder balls 1045, and the die package itself, through the metal layer in the substrate 1040, and to the liquid flowing through the internal flow holes 1010. Note that, although not illustrated, the chip package 1005 is located on a PCB that is sealed within a housing and forms a chamber that contains the transfer liquid.

[0075] Figure 10B illustrates a similar configuration for a wire-coupled ball grid array chip, where the die 1050 is connected to the substrate 1040 through solder bumps 1055. The configuration of the through-holes 1010 remains the same. Through-holes can also be used in other types of component packages and are independent of the package format.

[0076] Figure 10C illustrates an exemplary configuration of in-chip cooling in which the transfer fluid is in contact with the die 1060. The die 1060 is connected to the substrate 1040. The in-chip flow hole 1070 for liquid cooling opens in the center of the package 1005 so that the liquid 1075 is in direct contact with the inside of the die 1060 and the package 1005. Plating 1015 can be used on the outside of the substrate 1040 to increase thermal conductivity.

[0077] Figure 10D illustrates intrachip cooling for a system containing chiplets within an integrated circuit package. In this configuration, multiple chiplets are present within the integrated circuit package 1005. While this configuration illustrates a direct contact configuration in which the liquid is in direct contact with the die, those skilled in the art will understand that configurations shown in Figures 10A and 10B, in which a flow path contains the transfer fluid and the transfer fluid does not come into direct contact with the die, can also be used with chiplets.

[0078] Figures 11A to 11B illustrate an illustrative flip-chip package with a liquid flow hole. The flip-chip package includes a solder ball 1040 and a plastic overmold 1030 covering one or more chiplets or dies. The in-chip liquid flow hole 1035 passes through a portion of the substrate of the chip package, as shown. Figure 11B illustrates the same flip-chip without the plastic overmold, showing the die and trace bonded to the substrate. In this example, the in-chip liquid flow hole 1185 is located on the outer periphery of the flip-chip. Figures 10A to 11B illustrate chips with various contact types and configurations. The system is chip-type independent and can be used with the illustrated types of contacts and chip packages, or with any other contacts or chip packages that can be modified to include the described in-chip flow hole.

[0079] Figure 12 is an illustrative cross-section of a chip having a liquid flow hole connected to the inner surface of a PCB. The liquid flow hole 1220 is in contact with the inner surface 1215 of the PCB 1210. The inner surface 1215 of the PCB is generally a copper layer, providing a contact surface with the PCB 1210. By using plating 1230 on the edge of the liquid flow hole 1220, heat transfer from the inner surface of the PCB to the transfer fluid flowing through the flow hole 1220 is increased. This illustrative diagram can be used to understand the connection between an external liquid flow hole to the PCB and an internal liquid flow hole through the IC substrate.

[0080] Figures 13A to 13C illustrate an example of a system including a liquid driver. The transfer fluid moves through the housing by the fact that when the transfer fluid is heated, its density decreases and therefore it rises, and when it is cooled by contact with the housing, it descends. However, in various embodiments, a liquid driver 1036 is added to the housing, as illustrated in Figures 13A to 13C. The liquid driver 1360 may be, for example, an integrated micropump in the housing configured to actively circulate the transfer fluid, an in-housing vibration motor to create mechanical agitation, a small underwater fan or propeller, an in-housing thermoelectric cooler (TEC) to create a temperature gradient and facilitate fluid movement through a thermal cycle, a speaker to generate sound waves, and a piezoelectric buzzer to create ultrasonic vibrations and facilitate the movement of the transfer fluid. Such a liquid driver may be used with all configurations of single-sided or double-sided housings, as well as all configurations of flow holes.

[0081] The liquid driver 1360 may be continuously on to continuously move the transfer fluid, or the system may turn the liquid driver on and off as needed. The system may include a thermal sensor and controller 1350 for the liquid driver 1360. The thermal sensor and controller 1350 may be one or more chips in a housing that provide temperature sensing and control the operation of the liquid driver 1360. In this embodiment, the controller 1350 may turn on the liquid driver 1360 when the temperature exceeds 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 transfer fluid and reduce power consumption by the liquid driver 1360 when not needed or when the reduced flow rate is sufficient. Figure 13A illustrates an exemplary fan motor that may be used as a liquid driver.

[0082] Figure 13B illustrates a vibration motor that can be used as a liquid driver. 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 / casing, an eccentric mass, a motor shaft, a commutator and brushes, windings / coils, and mounting pins / leads. The housing / casing is an outer 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 is an eccentric mass (often an eccentric weight) attached to the motor shaft. When the motor rotates, this mass creates an imbalance, resulting in vibration. The motor shaft is the axis of rotation connected to the eccentric mass. The rotation of the shaft is what drives 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 create a magnetic field when current passes through them. The interaction between this magnetic field and the permanent magnets inside the motor causes rotation. Alternatively, non-magnetic drivers may be used, as is known in the art. Mounting pins / leads extend from the motor housing and are used to secure the motor to the PCB and provide electrical connectivity.

[0083] When power is supplied to the motor 1370 through mounting pins / leads, current flows through the windings. The current through the windings generates a magnetic field that interacts with the permanent magnets inside the motor, causing the shaft to rotate. As the motor shaft rotates, the eccentric mass creates a centrifugal force because of its eccentricity. This force generates vibrations. These vibrations are transmitted through the motor housing to the PCB, and then to the device to which the PCB is mounted, providing movement to the transfer fluid and increasing its circulation speed.

[0084] Figure 13C illustrates a propeller motor that can be used as a liquid driver in this system. The propeller motor is similar to the vibration motor described above, but instead of having an eccentric weight to generate vibration, it has a propeller mounted on a shaft. This configuration is designed to create a liquid flow, improving cooling efficiency within the system. The propeller can be configured to generate either a unidirectional flow of the transfer fluid or a multidirectional flow of the transfer fluid.

[0085] The system, in one configuration, includes a housing / casing, propeller, motor shaft, commutator and brushes, windings / coils, and mounting pins / leads. The housing protects the internal components and provides structural mounting to the PCB, thereby ensuring the motor's durability and integrity. The motor shaft is connected to the motor. The propeller is mounted on the motor shaft and causes an increase in the fluid flow velocity within the cooling chamber. The blade design ensures efficient movement of the transfer fluid.

[0086] Inside the motor, the commutator and brushes facilitate the flow of current through the windings, causing the motor to rotate. The windings / coils generate a magnetic field as current flows through them, interacting with the permanent magnets inside the motor to produce rotation. Mounting pins secure the motor to the PCB and provide electrical connectivity for supplying power to the motor.

[0087] When power is supplied to the motor through mounting pins / leads, current flows through the windings. This current generates a magnetic field within the windings, which interacts with the permanent magnets inside the motor, causing the motor shaft to rotate. The rotation of the motor shaft rotates the propeller, creating a flow of liquid within the chamber. The increased velocity of the liquid flow generated by the propeller helps to distribute heat more evenly within the chamber, improving overall cooling efficiency. This can significantly improve the performance and reliability of electronic components by maintaining a more uniform temperature across the entire surface of the cooled components.

[0088] In another embodiment, a different type of motor may be used as part of the fluid driver. The motor may not contain permanent magnets, such as an induction motor, a wound-rotor motor, a synchronous reluctance motor, an electrostatic motor, or a motor of the type that uses a piezoelectric element.

[0089] Liquid drivers can be adapted to different sizes and configurations of cooling chambers, making them versatile for a variety of applications. Using propeller motors within the housing of liquid cooling systems represents a significant advance in maintaining optimal operating temperatures for high-performance electronic components.

[0090] Figures 14A to 14C illustrate the configuration of a liquid cooling system that provides electrical isolation. In this configuration, the system's metal enclosure acts as effective shielding against radiation, electromagnetic interference (EMI), and radio frequency interference (RFI). In environments where high-performance electronic components operate, internally generated electromagnetic noise or electromagnetic noise received from external sources can significantly affect the performance and reliability of sensitive circuits. EMI and RFI are common problems in modern electronic systems, particularly those operating in high-density environments such as data centers, telecommunications systems, and industrial applications.

[0091] The metal enclosure within the system forms a natural Faraday cage around the sealed components. A Faraday cage is a structure made of conductive material that blocks electromagnetic fields by redistributing charge around its exterior, thereby preventing the transmission of interference through the enclosure. In this configuration, the metal enclosure serves a dual purpose: protecting internal components from external electromagnetic interference and preventing any radiation / emissions occurring within the system from affecting nearby sensitive devices.

[0092] The continuous conductive surfaces and grounding points of a metal enclosure allow for effective mitigation of 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 telecommunications systems, medical devices, and aerospace electronics.

[0093] Furthermore, the synergistic integration of the system's thermal management and EMI / RFI shielding capabilities adds another layer of reliability to the entire system. The metal enclosure ensures efficient heat dissipation through advanced surface treatment and structural design, while simultaneously maintaining signal integrity and reducing the susceptibility of sealed components to external interference. As a result, the system not only performs well thermally but also meets stringent requirements for electromagnetic compatibility (EMC), resulting in an extremely robust system.

[0094] By incorporating EMI / RFI shielding as a system feature, sealed liquid-cooled systems offer a comprehensive solution for improving both the thermal and electrical reliability of high-performance electronic devices. This dual functionality further enhances the system's benefits across a wide range of industries where both thermal management and electromagnetic shielding are critical considerations.

[0095] For shielding purposes, the enclosure is grounded. The connection can run along the inner edge of the enclosure. In various embodiments, the grounding surface of the PCB can be used for this connection. In various embodiments, the grounding uses aluminum (or other metal) fingers 1410 along the inner edge of the enclosure. These metal fingers mate with copper traces on the PCB to provide shielding for the electronic equipment inside the chamber.

[0096] In various embodiments, exposed traces 1435 on PCB 1430 following an internal silkscreen are used. Traces 1435 are stitched with stitching vias 1445, which are spaced at high frequency between the upper and lower ground traces, to form additional shielding for the electronics inside the chamber against radiation, EMI, RFI, and electrostatic discharge (ESD) pulses. These features also reduce electromagnetic noise leaking from within the PCB dielectric. This makes it possible to use the components with the chamber in highly sensitive environments, locations where radiation leakage is a concern, and high-radiation environments.

[0097] Figure 15 is a flowchart illustrating the use of electronic design automation (EDA) tools for designing a liquid cooling system. Integrating sealed liquid cooling technology into electronic products can significantly improve their thermal management capabilities. The use of advanced electronic design automation (EDA) tools allows designers to seamlessly integrate sealed liquid cooling features into the design, simulate thermal performance, and optimize production. Figure 15 provides a typical workflow for this design. The process begins in block 1510. A typical PCB design process begins after the completion of the schematic diagram, and the components are exported to the design software. The software imports all components and first places them in rows and columns outside the PCB board contour. The designer then defines the PCB contour and begins placing the components in the desired layout. EDA tools often include automatic placement features that optimize component placement for routing efficiency, taking into account clocking / interference / heat dissipation. Adding integrated sealed liquid cooling design capabilities can provide automatic placement preferences based on enclosure positioning for heat dissipation, as well as the size and location of the liquid flow holes. This process begins after the initial layout of the circuit components on the PCB.

[0098] In block 1515, components are grouped in the schematic design package to form one or more clusters that will be covered by a housing. These clusters are referred to as Liquid Cooling Clusters (LCCs). This may be done by the designer or automatically based on the identification of components and their expected heat dissipation needs. In PCB design software, these groups are selected, assigned to LCCs, and configured and optimized. In various embodiments, a single printed circuit board may contain multiple LCCs.

[0099] In block 1520, specific configuration data is received for each LCC, which may include one or more of the following: housing arrangement, chamber dimensions, gasket options, geometric preferences, mounting hole positioning, liquid flow hole position and size, and shielding. The configuration data may be entered by the designer. Some of the configuration data may be generated automatically based on expected usage configuration data. For example, usage configuration data may include chips in the chamber, expected heat generation, expected position of the final product, and use cases. The system may then generate chamber configuration data based on the usage configuration data. For example, the chamber volume may be selected based on the configuration of the components and the cooling requirements of the components. The amount of liquid in the system, and the resulting housing size, are selected according to the cooling requirements of the components.

[0100] Enclosure placement defines the options for positioning the liquid chamber on the top, bottom, or sides of the PCB. Enclosure dimensions define the maximum height, material thickness, and geometric cooling features (e.g., ribs, studs). Gasket options allow selection from standard gasket sizes or customization based on design requirements. Geometric preferences for the enclosure allow selection of rectangular, square, number of corners, and symmetry requirements for cost-effectiveness in mass production. Mounting holes specify the number, spacing, and positioning of mounting holes for stability. Liquid flow holes specify the number, arrangement, and dimensions of the flow holes. Liquid flow holes can also specify plating and power surface mounts for heat conduction paths. Optional EMI / RFI shielding provides specifications for stitching vias around the enclosure, including spacing and planar mounting.

[0101] In block 1530, the enclosure design is created based on the LCC and configuration data. The designer can ensure that the chamber encloses all selected components by manually drawing the chamber contour or by using an automated function.

[0102] In block 1535, the automatic placement tool optimizes the position and lateral configuration of components for connectivity and height constraints. Once the components are placed, the designer can manually adjust and modify them.

[0103] In block 1540, the LC module prevents interference with the sealing and ensures leak-free operation by calculating the keep-out zone based on the chamber specifications. This data is provided to the EDA tool for use in routing and clock design.

[0104] Following routing, liquid flow holes are located in block 1545. The liquid flow holes may be located in any of the above locations, as needed, on the PCB outside the area of ​​the component, under the component (between chips), and through the component package (inside the chip).

[0105] In block 1550, the system analyzes the performance metrics of the LCC based on simulations. Simulation parameters may include chamber specifications (thickness, material type, coating, and texture), expected environmental conditions (ambient temperature, airflow, and external influences), component power profiles (power consumption curves and thermal energy generation at various temperatures), and transfer fluid characteristics (density, heat capacity, and type of transfer fluid used).

[0106] In block 1555, the tool optionally calculates outputs such as steady-state temperature, thermal rise curve, chamber volume and weight, and detailed geometry. Then, in block 1560, the designer can fine-tune the details and iterate as needed.

[0107] Once the design is complete, the final design is exported in block 1565. The final design may be in a format such as STL, STEP, GES, or CNC-compatible G-code for manufacturing. The process then ends in block 1570.

[0108] Using EDA tools for the design and simulation of sealed liquid cooling systems offers numerous advantages, including efficiency, optimization, robustness, cost reduction, performance, and integration into existing workflows.

[0109] Rapid prototyping and iteration of designs with real-time feedback provides increased efficiency. The ability to test various configurations and parameters to achieve optimal thermal performance provides optimization. Improved thermal management enhances the reliability and durability of electronic products, increasing robustness. Reduced development time and improved manufacturability lead to lower production costs. Increased energy efficiency and extended lifespan of electronic components due to effective heat dissipation enhance performance. By utilizing EDA tools, designers can more effectively integrate sealed liquid cooling technology into their products, ensuring that electronic devices meet the stringent thermal requirements of modern applications.

[0110] As described above, sealed liquid cooling systems utilize leak-proof chambers and one or more types of liquid flow ports to allow the use of a transfer fluid to more efficiently transfer heat from one or more components. This has numerous applications and advantages and can be used to improve critical metrics for computing systems.

[0111] The demand for increased computational efficiency and density has grown in parallel with advancements in semiconductor technology. Two key metrics, computation / watt efficiency and computational density, serve as important performance indicators (KPIs) in evaluating computing systems, particularly in applications where energy consumption, space constraints, and operating costs are major considerations. As silicon-based systems evolve, power density challenges have emerged as a significant factor impacting both of these KPIs, necessitating more sophisticated thermal management solutions.

[0112] Computational / watt efficiency refers to the amount of computational work a system can perform per watt of power consumed, and is typically measured in floating-point operations per second (FLOPS). This metric is essential in a variety of contexts, including: • Energy Management: Power consumption remains a significant cost factor in data centers and high-performance computing environments; therefore, systems with high compute / watt efficiency result in reduced energy consumption for a given computational workload. • Environmental impact: Reducing power consumption in computing systems directly mitigates the carbon footprint associated with data centers and other energy-intensive operations, contributing to global sustainability efforts. • Thermal management: Efficient use of power leads to reduced heat output, minimizing the need for large-scale cooling infrastructure and increasing the operating life of equipment by reducing thermal stress. • Battery Use: In portable or remote computing systems that rely on battery power, maximizing computation / watt efficiency is crucial to extend the operating life while maintaining performance.

[0113] Computational density measures the computing power available in a given physical space and is often expressed as FLOPS per cubic meter or per rack within a data center. This KPI is particularly important in environments where space is limited or costly. Computational density is used for improvement: • Spatial optimization: High computational density is crucial in facilities with constrained physical space, such as edge computing nodes or urban data centers, enabling greater computing power in a smaller footprint. • Cost-effectiveness: Increased computing density reduces the need for expanded data center space or additional physical infrastructure such as cooling systems, thereby lowering both capital and operating expenses. • Scalability: Systems with higher computational density enable more scalable computational growth without a proportional increase in physical space requirements, and allow for more efficient capacity planning. • Maximizing Performance: Optimizing space usage for computing resources enables organizations to deploy more powerful, higher-performing systems, leading to improved computing throughput and efficiency.

[0114] As semiconductor manufacturing processes advance, transistors and other components are increasingly densely packed onto silicon dies, leading to a corresponding increase in power density. This presents several challenges: • Heat generation: As power density increases, the amount of heat generated within a smaller surface area increases, making effective heat dissipation more difficult. • Complexity of thermal management: Effective management of the thermal load from high-density silicon dies requires advanced cooling solutions to prevent thermal throttling, reduced system efficiency, and potential hardware failures.

[0115] This challenge directly impacts both computation / watt efficiency and computation density, making it a critical consideration across various use cases. For example, in data centers, high-density silicon designs lead to increased thermal output, requiring sophisticated cooling solutions to maintain efficiency. Power density challenges highlight the need for improved thermal management to avoid energy waste in cooling systems. Increasing computation density in data centers presents significant thermal management challenges due to the difficulty in dissipating heat from densely packed components. To overcome these limitations, advanced cooling techniques, such as the sealed liquid cooling systems described in this application, can be used.

[0116] Edge devices are often deployed in environments without dedicated cooling infrastructure and must efficiently manage heat to maintain operational efficiency. Power density challenges are particularly severe for edge devices because small, high-density components generate significant heat in limited spaces. Additionally, achieving high computational density in physically confined edge environments requires compact, high-density silicon chips. The power density challenges of edge devices reinforce the need for improved passive or active cooling methods to prevent overheating, such as the sealed liquid cooling systems described herein.

[0117] AI workloads place high demands on GPUs and accelerators, which are subject to power density challenges. Effective thermal management of these high-density components is crucial to maintaining efficiency and avoiding thermal throttling. AI clusters require high computational density to support multiple graphical processing units (GPUs) within a single chassis or rack. To maintain high-density AI computing without compromising performance, advanced cooling techniques, such as the sealed liquid cooling systems described herein, are necessary to mitigate the thermal effects of power density challenges.

[0118] Game systems, particularly in GPUs and CPUs, utilize high-density silicon chips, and power density issues exacerbate the difficulty of heat dissipation. Customized cooling solutions are often used to maintain efficiency and performance. As game systems increasingly require more compact designs and higher power output, the power density challenge necessitates effective thermal management, such as sealed liquid cooling systems, to ensure high performance without overheating.

[0119] 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 maintaining system reliability and performance. Aerospace applications, in particular, require lightweight and compact systems where space and weight are limited. Innovative cooling solutions, such as sealed liquid cooling systems, are needed to address power density challenges and maintain high computational density in critical environments.

[0120] Therefore, power density challenges are becoming increasingly prominent across a wide range of fields as silicon dies become denser, components shrink, and more computationally intensive processes are used. This challenge impacts compute / watt efficiency and compute density across various industries, including data centers, edge computing, AI workloads, gaming systems, and automotive and aerospace applications. By addressing the thermal management challenges posed by high-density silicon designs utilizing the aforementioned sealed liquid cooling systems, organizations can optimize system performance, reduce energy consumption, and prevent the detrimental effects of overheating.

[0121] Figure 16 is a block diagram of a specific machine that may be used in conjunction with the present invention. The computing system described may be used to provide the electronic design automation (EDA) tools described above. Furthermore, a sealed liquid cooling system may be used in such a computing system to cool one or more components. However, it will be apparent to those skilled in the art that other alternative systems with various system architectures may also be used.

[0122] The data processing system illustrated in Figure 16 includes a bus or other internal communication means 1640 for transmitting information and a processing unit 1610 connected 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. Additionally or alternatively, the system may include a graphical processing unit (GPU) or other processing system.

[0123] The system may further include random access memory (RAM) or other volatile storage device 1620 (referred to as memory) connected to the bus 1640 for storing information and instructions executed by the processor 1610. The main memory 1620 may be used to store temporary variables or other intermediate information during the execution of instructions by the processing unit 1610.

[0124] The system may also include a read-only memory (ROM) 1650 and / or static storage device 1650 connected 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 or optical disk and its corresponding disk drive, flash memory, or other storage device that can store data when the system is not powered. The data storage device 1630 is connected to the bus 1640 for storing information and instructions.

[0125] The system may be further connected to an output device 1670 for outputting information, such as a cathode ray tube (CRT) or liquid crystal display (LCD), which is connected to bus 1640 via bus 1660. The output device 1670 may be a visual output device, an audio output device, and / or a tactile output device (e.g., vibration).

[0126] An input device 1675 may be connected to bus 1660. Input device 1675 may be an alphanumeric input device, such as a keyboard, including alphanumeric and other keys, to enable the user to transmit information and command selections to processing unit 1610. Additional user input devices 1680 may be included. One such user input device 1680 is a cursor control device 1680, such as a mouse, trackball, stylus, cursor directional keys, or touchscreen, which may be connected to bus 1640 via bus 1660 to transmit directional information and command selections to processing unit 1610 and control movement on display device 1670.

[0127] Another device that may optionally be connected to the computer system 1600 is a network device 1685 for accessing other nodes of the distributed system via a network. The communication device 1685 may include any of several commercially available networking peripheral devices, such as Ethernet, Token Ring, the Internet, or those used to connect to wide area networks, personal area networks, or wireless networks, or any other method of accessing other devices. The communication device 1685 may further be a null modem connection or any other mechanism that provides connectivity between the computer system 1600 and the outside world.

[0128] It should be noted that any or all of the components and related hardware of this system illustrated in Figure 16 may be used in various embodiments of the present invention.

[0129] Those skilled in the art will understand that a particular machine embodying the present invention may be configured in various ways according to a particular embodiment. The control logic or software for implementing the present invention may be stored in the main memory 1620, the mass storage device 1630, or other storage medium accessible locally or remotely to the processor 1610.

[0130] It will be apparent to those skilled in the art that the design process described herein may 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 a product including a computer-readable medium in which computer-readable program code is embodied and readable by mass storage device 1630, causing processor 1610 to operate according to the methods and teachings herein.

[0131] The computing system may also be configured as a handheld or portable device including a subset of the computer hardware components described above. For example, a handheld device may be configured to include only a bus 1640, a processor 1610, and memory 1650 and / or 1620. The handheld device may be configured to include a set of buttons or a set of input signaling components that the user can select from a set of available options. These may be considered as a first input device 1675 or a second input device 1680. The handheld device may also be configured to include an 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 may be used to implement such a handheld device. Implementations of the present invention for such a device will be obvious to those skilled in the art, given the disclosures of the present invention as provided herein.

[0132] The present invention can also be embodied in a dedicated device that includes a subset of the computer hardware components described above. For example, the device may include a processing unit 1610, a data storage device 1630, a bus 1640, and a memory 1620, and may not include an input / output mechanism, or may include only a rudimentary communication mechanism, such as a small touchscreen, that allows a user to communicate with the device in a basic manner. Generally, the more specialized the purpose of the device, the fewer elements are essential for it to function. In some devices, communication with the user may occur through 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 through a website or through other network-based connections via a network device 1685.

[0133] It will be understood by those skilled in the art that any configuration of a particular machine implemented as a computer system may be used according to its particular implementation. Control logic or software may be stored on any machine-readable medium accessible locally or remotely to the processor 1610. The machine-readable medium includes any mechanism for storing information in a format readable by a machine (e.g., a computer). For example, the machine-readable medium includes read-only memory (ROM), random-access memory (RAM), magnetic disk storage medium, optical storage medium, flash memory device, or other storage medium that may be used for temporary or permanent data storage. The control logic may be implemented as transmittable data, such as electrical, optical, acoustic, or other forms of propagating signals (e.g., carrier waves, infrared signals, digital signals, etc.).

[0134] The claims define the matters for which protection is sought.

[0135] In addition, aspects of this specification provide the following:

[0136] A liquid cooling system, Printed circuit boards (130, 240) and A gasket (115, 230) seated on the upper side of a printed circuit board (130, 240), the gasket (115, 230) surrounding one or more components (105) attached to the printed circuit board (130, 240), A housing (220, 260, 810) that sits on the gasket and is fastened to the printed circuit board, forming a sealing chamber together with the printed circuit board (130, 240) and the gasket (115, 230), A liquid cooling system comprising a transfer fluid (838) located within a sealing chamber and in contact with one or more components (105) mounted on a printed circuit board (130, 240).

[0137] The casing is, A first component (220) on the upper side of a printed circuit board, wherein the first side surface of the first component (220) is seated on a gasket, A liquid cooling system comprising: a second component (260) on the lower side of a printed circuit board, wherein the second side surface of the second component (260) is seated on a second gasket.

[0138] A liquid cooling system further comprising one or more liquid flow holes (110, 840, 935) within a printed circuit board, sized to allow circulation of a transfer fluid between the upper and lower sides of the printed circuit board.

[0139] A liquid cooling system in which one or more additional components are present on the printed circuit board outside the enclosure.

[0140] A liquid cooling system comprising one or more additional components, including input / output (I / O) components.

[0141] A liquid cooling system, A liquid cooling system comprising a housing having a first compartment (520) and a second compartment (525), wherein the first compartment is surrounded by a gasket to provide a sealed housing, and the second compartment further comprises a non-leak-proof housing.

[0142] A liquid cooling system in which the transfer fluid contains a two-phase liquid that exists in both liquid and gaseous states within the chamber.

[0143] A liquid cooling system in which the transfer fluid contains one or more perfluorinated compounds (PFCs) and perfluorocarbons.

[0144] A liquid cooling system, The printed circuit board further includes silkscreen printed patterns (350, 360) for positioning the gasket, A liquid cooling system in which a gasket (315) is positioned on a silkscreen printed pattern, the silkscreen printed pattern provides positioning and sealing for the gasket, or the silkscreen printed pattern is on one or both sides of the gasket, and the gasket contacts the printed circuit board without the silkscreen printed pattern being positioned between the gasket and the printed circuit board.

[0145] The components comprise an integrated circuit having a component package and contacts, and the system is A liquid cooling system further comprising interchip liquid flow holes (935) in the printed circuit board beneath the integrated circuit, to allow the transfer fluid to pass through the printed circuit board and reach the volume beneath the integrated circuit.

[0146] The components comprise an integrated circuit having a die and contacts within the component package, and the system is A liquid cooling system further comprising sealed liquid through-holes within the component package, configured to allow the transfer fluid to pass through the component package and remove heat from the die.

[0147] A liquid cooling system, A liquid cooling system further comprising an intrachip liquid through-hole that enters one or more packages of components on a printed circuit board.

[0148] A liquid cooling system in which a liquid through-hole in the chip passes through one or more of the integrated circuit substrate and the integrated circuit overmolding.

[0149] A liquid cooling system in which the first portion of the liquid through-holes within the chip that pass through the circuit board is plated. A liquid cooling system in which the second portion of the liquid through-holes within the chip that pass through the overmolding is not plated.

[0150] The liquid cooling system according to claim 10, wherein the transfer fluid replaces one or more thermal ground connections of an integrated circuit.

[0151] A liquid cooling system, The system further includes an active fluid driver configured to facilitate the movement of the fluid within the housing, A liquid cooling system in which the liquid driver is one or more of the following: an integrated micropump in a housing configured to optionally actively circulate the transfer fluid; a vibration motor in the housing to create mechanical agitation; a small underwater fan or propeller; a thermoelectric cooler (TEC) in the housing to create a temperature gradient and facilitate fluid movement through a thermal cycle; a speaker to generate sound waves; and a piezoelectric buzzer to create ultrasonic vibrations and facilitate the movement of the transfer fluid.

[0152] A liquid cooling system further comprising a control mechanism for adjusting the speed and direction of a motor, thereby controlling the flow rate and pattern of the transfer fluid.

[0153] A liquid cooling system in which an active liquid driver is mounted on a printed circuit board and positioned to direct the transfer fluid across a subset of components with the highest thermal output.

[0154] A liquid cooling system, A liquid cooling system further equipped with sensors to monitor the temperature of the transfer fluid, and connected to a feedback system for adjusting the speed of the liquid driver for optimal cooling performance.

[0155] A liquid cooling system in which at least one of one or more components comprises a chiplet having multiple dies within a single package.

[0156] A liquid cooling system, further comprising the integration of an electronic design automation (EDA) tool to enable the design of the liquid cooling system, wherein the EDA tool is for laying out one or more components on a printed circuit board, and the EDA tool is A user interface that allows the user to define a cluster of one or more components contained within the enclosure, A liquid cooling system further comprising an automatic positioning tool for designing a housing based on the characteristics and positioning of one or more components.

[0157] A liquid cooling system where an automated positioning tool for designing the enclosure further calculates the enclosure's volume, weight, and geometric shape.

[0158] An automated positioning tool further identifies the gasket specifications of the housing for the liquid cooling system.

[0159] A liquid cooling system, A liquid cooling system further comprising a motor having a shaft-mounted propeller designed to generate a liquid flow within the housing, thereby improving the distribution of heat from one or more components.

[0160] A method using a sealed liquid cooling system, The process involves placing a gasket on the printed circuit board that surrounds a portion of the printed circuit board, The housing is seated on the gasket, and the housing is fastened to the printed circuit board, forming a chamber between the printed circuit board, the gasket, and the housing, thereby forming a sealing chamber. A method comprising filling a chamber with a transfer fluid.

[0161] It is a method, A method comprising arranging a plurality of liquid flow holes within a printed circuit board such that a transfer fluid can flow through the liquid flow holes between the lower part of the lower housing of the printed circuit board and the upper part of the upper housing of the printed circuit board, further comprising optionally arranging the liquid flow holes to be interchip liquid flow holes beneath circuits on the printed circuit board.

[0162] In the aforementioned specification, the present invention is described with reference to certain exemplary embodiments. However, it will be apparent that various modifications and changes may be made without departing from the broader spirit and scope of the invention as described in the appended claims. Furthermore, the various examples and configurations are generally designed to be mixed and adapted, as long as they are not mutually exclusive. Accordingly, this specification and the drawings should be considered illustrative rather than restrictive.

Claims

1. A liquid cooling system, Printed circuit board (130, 240) and A gasket (115, 230) seated on the upper side of the printed circuit board (130, 240), the gasket (115, 230) surrounding one or more components (105) mounted on the printed circuit board (130, 240), A housing (220, 260, 810) that sits on the gasket and is fastened to the printed circuit board, and together with the printed circuit board (130, 240) and the gasket (115, 230), forms a sealing chamber, A liquid cooling system comprising a transfer fluid (838) located within the sealing chamber and in contact with one or more components (105) mounted on the printed circuit board (130, 240).

2. The aforementioned enclosure is The first component (220) on the upper side of the printed circuit board, wherein the first side surface of the first component (220) is seated on the gasket, The liquid cooling system according to claim 1, further comprising: a second component (260) on the lower side of the printed circuit board, wherein the second side surface of the second component (260) is seated on a second gasket.

3. The liquid cooling system according to claim 2, further comprising one or more liquid flow holes (110, 840, 935) in the printed circuit board, which are sized to allow circulation of the transfer fluid between the upper and lower sides of the printed circuit board.

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

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

6. A liquid cooling system according to any one of claims 1 to 5, comprising a housing having a first compartment (520) and a second compartment (525), wherein the first compartment is surrounded by the gasket to provide the sealed housing, and the second compartment further comprises a housing that is not leakproof.

7. The liquid cooling system according to any one of claims 1 to 6, wherein the transfer fluid comprises a two-phase liquid and is in both liquid and gaseous states within the chamber.

8. The liquid cooling system according to claim 7, wherein the transfer fluid contains one or more perfluorinated compounds (PFCs) and perfluorocarbons.

9. To position the gasket, the printed circuit board further comprises patterns (350, 360) printed on a silkscreen, A liquid cooling system according to any one of claims 1 to 8, wherein the gasket (315) is positioned on the silkscreen printed pattern, the silkscreen printed pattern provides positioning and sealing for the gasket, or the silkscreen printed pattern is on one or both sides of the gasket, the gasket contacts the printed circuit board without the silkscreen printed pattern being positioned between the gasket and the printed circuit board.

10. The aforementioned components include a component package and an integrated circuit having contacts, and the system is The liquid cooling system according to any one of claims 1 to 9, further comprising interchip liquid flow holes (935) in the printed circuit board below the integrated circuit, for allowing the transfer fluid to pass through the printed circuit board and reach the volume below the integrated circuit.

11. The aforementioned component comprises an integrated circuit having dies and contacts within a component package, and the system is The liquid cooling system according to any one of claims 1 to 10, further comprising a sealed liquid through-hole in the component package, configured to allow the transfer fluid to pass through the component package and remove heat from the die.

12. The housing further comprises an active liquid driver configured to facilitate the movement of the transfer fluid within the housing, A liquid cooling system according to any one of claims 1 to 11, wherein the liquid driver is optionally one or more of the following: an integrated micropump in the housing configured to actively circulate the transfer fluid; a vibration motor in the housing for creating mechanical agitation; a small underwater fan or propeller; a thermoelectric cooler (TEC) in the housing for creating a temperature gradient and facilitating fluid movement through a thermal cycle; a speaker for generating sound waves; and a piezoelectric buzzer for creating ultrasonic vibrations and facilitating the movement of the transfer fluid.

13. The liquid cooling system according to claim 12, further comprising a motor having a propeller mounted on a shaft designed to generate a liquid flow within the housing, thereby improving the distribution of heat from one or more components.

14. A method using a sealed liquid cooling system, A gasket is placed on the printed circuit board to surround a portion of the printed circuit board, The housing is seated on the gasket, and the housing is fastened to the printed circuit board, thereby forming a chamber between the printed circuit board, the gasket, and the housing, and thus forming a sealing chamber. A method comprising filling the chamber with a transfer fluid.

15. The method according to claim 14, wherein a plurality of liquid flow holes are arranged in the printed circuit board such that the transfer fluid can flow through the liquid flow holes between the lower part of the housing below the printed circuit board and the upper part of the housing above the printed circuit board, further comprising optionally arranging the liquid flow holes to be interchip liquid flow holes below circuits on the printed circuit board.

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