A cooling system for server motherboards

Abstract

This invention proposes a cooling system suitable for server motherboards, relating to the field of cooling technology. The cooling system includes a cooling component, a cooling chamber, and a cooling plate. A gas-solid mixture generated by the cooling component is sprayed onto the cooling plate through the cooling chamber, rapidly cooling the chip attached to the back of the cooling plate. The cooling component includes a reaction element and a spray element connected to the reaction element. The cooling chamber and the spray element are connected by threads. The cooling plate is fixedly connected to the bottom of the cooling chamber, and the cooling plate is in close contact with the chip. The reaction element converts liquid carbon dioxide into subcritical carbon dioxide, which is then sprayed into the cooling chamber through the spray element. Because the cooling plate is positioned in the spray direction of the spray element, the gas-solid mixture is ultimately sprayed directly onto the cooling plate, rapidly cooling it and consequently, the chip attached to the cooling plate is also rapidly cooled.

Description

Technical Field

[0001] This invention relates to the field of cooling technology, and in particular to a cooling system suitable for server motherboards. Background Technology

[0002] In the fields of semiconductor chip manufacturing and high-performance computing, as integrated circuit manufacturing processes have entered the sub-3nm node, the heat flux density of high-performance chips has exceeded 1000W / cm², making traditional heat dissipation technologies insufficient to meet the demands for efficient and precise temperature control. Existing chip heat dissipation methods mainly include air cooling, liquid cooling circulation systems, heat pipe heat conduction, and passive heat dissipation schemes based on phase change materials. While circulating coolant absorbs heat from the chip surface, this relies on fluid convection heat transfer mechanisms, resulting in a bottleneck in thermal conductivity.

[0003] Traditional liquid cooling media (such as water and fluorinated liquids) have limited specific heat capacity and thermal conductivity, which can easily lead to local hot spots when dealing with instantaneous high heat flux density, resulting in chip performance degradation or even burnout. In addition, existing phase change cooling systems require complex piping and external compressors, which pose a risk of leakage and have high maintenance costs. Furthermore, existing phase change thermal storage materials show significant thermal conductivity degradation (a decrease of more than 40%) after 200 solid-liquid phase changes, and are prone to interface delamination at high temperatures.

[0004] Existing defects have severely limited the performance release of high power density chips. Actual tests show that when the temperature exceeds 125℃, the maximum turbo frequency of 7nm process CPUs drops by up to 28%, and the electromigration effect caused by high temperature can shorten the lifespan by more than 60%. In the data center field, traditional cooling solutions account for 40% of the overall energy consumption, becoming a key bottleneck restricting the energy utilization efficiency from breaking through 1:1. Therefore, there is an urgent need for a chip high-efficiency heat dissipation solution that combines fast thermal response capability, compact structure and long-term reliability. Summary of the Invention

[0005] In view of the problems existing in the above-mentioned cooling systems applicable to server motherboards, this invention is proposed.

[0006] Therefore, the problem to be solved by this invention is how to efficiently cool down server motherboards.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a cooling system suitable for server motherboards, comprising a cooling component, including a reaction element and a spray element communicating with the reaction element; The reactant is capable of generating subcritical carbon dioxide, which is then ejected from the injector. A cooling box, wherein the cooling box is connected to the spraying component by a thread; A cooling plate is fixedly connected to the bottom of the cooling box, and the cooling plate is in close contact with the chip.

[0008] As a preferred embodiment of the cooling system for server motherboards described in this invention, the spraying component includes an input pipe and an air inlet disposed on the spray head. The input pipe is connected to the reaction device, and the air inlet is connected to the air pump. Gas, specifically carbon dioxide, is introduced into the nozzle via the air pump.

[0009] As a preferred embodiment of the cooling system for server motherboards described in this invention, the nozzle is provided with a first thread.

[0010] As a preferred embodiment of the cooling system for server motherboards described in this invention, the cooling box is provided with a second thread that mates with the first thread; The nozzle can be screwed into the cooling box, and the nozzle sprays directly at the cooling plate.

[0011] As a preferred embodiment of the cooling system for server motherboards described in this invention, the cooling box is provided with a vacuum wall, and the vacuum wall is provided on all surfaces of the cooling box except for the surface where the cooling plate is located.

[0012] As a preferred embodiment of the cooling system for server motherboards described in this invention, an extension plate is provided on the inner walls of the cooling box, and the length of the extension plate is 0.2 times the length of the cooling plate.

[0013] As a preferred embodiment of the cooling system for server motherboards described in this invention, the cooling box is provided with an exhaust pipe, and the exhaust pipe is provided with threads.

[0014] As a preferred embodiment of the cooling system for server motherboards described in this invention, the chip is provided with a temperature sensor, and the temperature sensor is electrically connected to the reactant.

[0015] As a preferred embodiment of the cooling system for server motherboards described in this invention, the reaction component includes a storage tank, a booster, and a temperature controller, and the storage tank, the booster, and the temperature controller are connected by a pipe. The booster and the temperature controller can convert liquid carbon dioxide into a subcritical state. The temperature sensor is electrically connected to the booster, and the pressure of the booster can be adjusted through the temperature sensor.

[0016] As a preferred embodiment of the cooling system for server motherboards described in this invention, the surface of the cooling plate is provided with irregular grooves.

[0017] The beneficial effects of this invention are: 1. Compared with single-phase liquid cooling medium, the overall cooling efficiency is improved by the triple heat transfer mechanism that occurs when the gas and solid phases collide with the cold plate. 2. The extension plate inside the spray box allows for more sustained cooling of the cold plate; 3. Furthermore, the design of the vacuum wall of the spray box can effectively isolate the internal and external temperatures, so that the cooling effect is only applied to the cold plate, improving the cooling efficiency and significantly reducing condensation. 4. At the same time, by setting up a thermal sensor, the carbon dioxide flow rate can be effectively and accurately controlled, thereby controlling the cooling temperature of the cold plate. 5. By using carbon dioxide for cooling, compared with the liquid cooling materials used in other cooling technologies, there is no need to worry about the derivative problems caused by leakage. It is environmentally friendly, harmless, and compatible with various applications, and will not cause damage to the application. 6. This cooling system cools the server motherboard chips. Compared with traditional liquid cooling and air cooling devices, it has a more compact structure, lower energy consumption, and lower overall cost. 7. Furthermore, liquid carbon dioxide mainly comes from the waste generated by power plants, and its price is low. By utilizing and recycling it, waste can be turned into treasure, thus improving energy efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an overall flowchart of a cooling system suitable for server motherboards.

[0020] Figure 2 This is a scenario diagram for a cooling system suitable for server motherboards.

[0021] Figure 3 This is a structural diagram of a cooling system suitable for server motherboards.

[0022] Figure 4 This is an enlarged structural diagram of the spray component for a cooling system suitable for server motherboards.

[0023] Figure 5 This is a cross-sectional view of a cooling system suitable for server motherboards.

[0024] Figure 6 This is a structural diagram of a cooling box for a cooling system suitable for server motherboards.

[0025] Figure 7 This is a cross-sectional view of a cooling box used in a cooling system for server motherboards.

[0026] Figure 8 This is a schematic diagram of the state of carbon dioxide. Detailed Implementation

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive, either alone or selectively, with other embodiments. Example 1

[0030] Reference Figure 1 and Figure 2 This is the first embodiment of the present invention. This embodiment provides a cooling system suitable for server motherboards. The cooling system suitable for server motherboards includes a cooling component 1, a cooling box 2, and a cold plate 3. The gas-solid mixture generated by the cooling component 1 is sprayed onto the cold plate 3 through the cooling box 2, so that the chip attached to the back of the cold plate 3 can be cooled down quickly.

[0031] Specifically, the cooling assembly 1 includes a reaction element 1-1 and a spray element 1-2 connected to the reaction element 1-1; Reactor 1-1 generates subcritical carbon dioxide, which is ejected from injector 1-2. The pressure and temperature of the carbon dioxide are controlled at a specific range. Figure 7 The subcritical range shown causes liquid carbon dioxide to transform into a subcritical state. Then, gaseous substances (such as carbon dioxide, air, etc.) are added at the injector 1-2, so that the injector 1-2 sprays out a gas-solid mixture.

[0032] Preferably, the cooling box 2 is connected to the spraying parts 1-2 by a thread.

[0033] Preferably, the cold plate 3 is fixedly connected to the bottom of the cooling box 2, and the cold plate 3 is in close contact with the chip.

[0034] In use, liquid carbon dioxide is converted into subcritical carbon dioxide through the reaction element 1-1, and then injected into the cooling box 2 through the spray element 1-2. Since the cold plate 3 is set in the spray direction of the spray element 1-2, the gas-solid mixture is ultimately sprayed directly towards the cold plate 3, thereby rapidly cooling the cold plate 3, and the chip attached to the cold plate 3 is also rapidly cooled down.

[0035] Example 2 Reference Figures 2-7 This is the second embodiment of the present invention, which is based on the previous embodiment.

[0036] Specifically, the spraying component 1-2 includes a nozzle 1-2-1, an input pipe 1-2-2 disposed on the nozzle 1-2-1, and an air inlet 1-2-3; The input pipe 1-2-2 is connected to the reaction vessel 1-1, and the air inlet 1-2-3 is connected to the air pump 1-2-4. Gas is input into the nozzle 1-2-1 through the air pump 1-2-4; the gas is carbon dioxide.

[0037] Preferably, the nozzle 1-2-1 is provided with a first thread 1-2-5. By screwing the nozzle 1-2-1 into the cooling box 2, it is easy to disassemble and assemble the whole, and also makes the whole more stable.

[0038] Preferably, the cooling box 2 is provided with a second thread 2-1 that mates with the first thread 1-2-5; Nozzle 1-2-1 can be screwed into cooling box 2, and the spray direction of nozzle 1-2-1 is directly facing the cold plate 3. Nozzle 1-2-1 sprays a gas-solid mixture towards the cold plate 3, and the gas-solid mixture is sprayed in a scattering form, which can more comprehensively cover the area of ​​cold plate 3. Furthermore, by spraying the gas-solid mixture directly onto the cold plate, a triple heat transfer mechanism can be brought about, namely, heat absorption by the sublimation of solid dry ice, heat transfer by the convection of gaseous carbon dioxide, and the conversion of the kinetic energy of micron-sized dry ice particles into surface energy.

[0039] When micron-sized dry ice particles (10-50 μm in diameter) strike the surface of a cold plate perpendicularly at a velocity ≥15 m / s, the formula for calculating their kinetic energy is:

[0040] in: E k The kinetic energy of micron-sized dry ice; m is the mass of micron-sized dry ice; v represents the impact velocity of micron-sized dry ice particles; ρ is the density of dry ice; r is the radius of the micron-sized dry ice particles; π is the ratio of the circumference of a circle to its diameter.

[0041] With typical values ​​( The kinetic energy of a single particle is calculated to be approximately (r=15μm, v=15m / s). J.

[0042] The collision instant (contact time approximately 0.1 μs) generates 10 8 Impact pressure in the Pa range exceeds the yield strength of copper (pure copper ≈ 70 MPa), causing plastic flow to occur on the surface of the cold plate 3. At the same time, about 35% of the kinetic energy is converted into surface defect energy (forming nanoscale pits), 20% is converted into lattice vibration energy (i.e., thermal energy), and the remainder is dissipated through elastic waves.

[0043] From a microscopic perspective, particle impacts create radial microcracks with characteristic sizes of 200-500 nm on the surface of the cold plate.

[0044] From a mesoscopic scale perspective, the crack network forms a penetration channel with a depth of 5-8 μm (increasing permeability to...). (magnitude) From a macroscopic perspective, it can increase the effective heat exchange area (the measured heat transfer coefficient of a rough surface is 210% higher than that of a smooth surface). Enhance the permeability of the working fluid (capillary pressure ΔP=2γcosθ / r, where γ is the surface tension, θ is the contact angle, and r is the diameter of the micron-sized dry ice particles). A transient micro-liquid reservoir is formed (extending the length of the gas-solid-liquid three-phase contact line).

[0045] Experimental results demonstrate that: through After several impact cycles, the microchannel structure retention rate was >85% (characterized by atomic force microscopy), and the surface wettability continued to improve (the contact angle decreased from the initial 112° to 69°).

[0046] This effect is essentially achieved through kinetic energy-driven self-generation of surface microstructures, which, while maintaining the integrity of the cold plate itself, constructs an in-situ heat transfer enhancement structure adapted to the working fluid characteristics. Compared to pre-fabricated microchannel methods, this dynamic penetration mechanism has real-time self-optimization characteristics—when the chip's thermal load changes, the surface microstructure characteristics can be dynamically altered by adjusting the CO2 injection parameters (velocity / particle concentration), achieving adaptive matching between heat dissipation performance and environmental conditions.

[0047] Moreover, compared with traditional liquid cooling and air cooling, it can be seen that the steady-state temperature of cooling by gas-solid mixture is 23% lower than that of liquid cooling, the cooling speed is 50% faster, the energy consumption is 50% of that of liquid cooling, and the temperature uniformity is improved by 100%.

[0048] As shown in the chart below: index Subcritical carbon dioxide cooling Traditional liquid cooling air-cooled Steady-state temperature: 85°C 50 65 85 Cooldown time (s) 30 60 120 Energy consumption (W) 40 80 15 Temperature uniformity (°C) ±1.5 ±3 ±5 Preferably, the cooling box 2 is provided with a vacuum wall 2-2. Except for the surface where the cold plate 3 is located, the cooling box 2 is provided with a vacuum wall 2-2. Through the design of the vacuum wall 2-2, the external heat input can be effectively isolated, and the internal cold output can also be prevented. Setting up vacuum wall 2-2 (vacuum degree ≤ Pa) Reduce external thermal interference, verified by the heat flux density formula:

[0049] Where ε is the emissivity and σ is the Stefan-Boltzmann constant.

[0050] For: heat leakage flux through the vacuum wall; The fourth power of the thermodynamic temperature outside the vacuum wall;

[0051] The fourth power of the thermodynamic temperature inside the vacuum wall; Meanwhile, by using carbon dioxide for refrigeration, carbon dioxide has a GWP (Global Warming Potential) of 1 and an ODP (October Small Potential) of 0, which is more environmentally friendly than HFO refrigerant (GWP=4) and has no PFAS residue risk.

[0052] characteristic HFO refrigerant Carbon dioxide refrigeration GWP 1-10 1 ODP 0 0 Environmental risks Contains PFAS Natural working material, risk-free Flammability Some are flammable Non-flammable Preferably, an extension plate 2-3 is provided on the inner walls of the cooling box 2, and the length of the extension plate 2-3 is 0.2 times the length of the cooling plate 3.

[0053] parameter size illustrate Extension plate width =Cold plate width The width should be the same as the corresponding edge of the cold-rolled steel plate to ensure full coverage of the cold-rolled steel plate edge. Extension plate depth =0.2 Cold plate length Take 20% of the length of the cold plate to form a sufficient reflux cavity. Extension plate thickness =0.1 cold sheet thickness Take 10% of the thickness of the cold-rolled plate to balance strength and thermal conductivity. Extension plate spacing =0.05 Cold plate length Maintaining a 5% clearance on each side facilitates the flow of the gas-solid mixture. Preferably, the cooling box 2 is provided with an exhaust pipe 2-4, which is threaded so that it can be directly screwed into the cooling box 2 without reducing the vacuum wall effect.

[0054] Preferably, a temperature sensor 2-5 is provided on the chip side, and the temperature sensor 2-5 is electrically connected to the reactant 1-1;

[0055] The flow rate of the gas-solid mixture is expressed in kg / min. P is the pressure applied to liquid carbon dioxide in the pressure booster temperature controller, so that its temperature is below the critical temperature (31.1℃) and its pressure is above the saturation pressure at that temperature, thus obtaining a subcritical fluid state; This refers to the temperature of the chip surface in steady state. Q represents the power of the cold zone, which is approximately equal to the heat absorbed during the phase change of carbon dioxide.

[0056] In the formula, Q represents the power of the cooling zone; The flow rate of the gas-solid mixture;

[0057] This is the latent heat of phase change of carbon dioxide (also called the latent heat of sublimation or latent heat of vaporization). in, ≈200kJ / kg. As can be seen from the above experiment, the flow rate can be adjusted in real time by setting temperature sensor 2-5. When the chip temperature is too low, the flow rate input of the gas-solid mixture is reduced, and when the chip temperature is too high, the flow rate input of the gas-solid mixture is increased.

[0058] Preferably, the reaction unit 1-1 includes a storage tank 1-1-1, a booster 1-1-2, and a temperature controller 1-1-3. The storage tank 1-1-1, the booster 1-1-2, and the temperature controller 1-1-3 are connected by a pipeline. The booster 1-1-2 can be a KSD301 model. The booster 1-1-2 and the temperature controller 1-1-3 can convert liquid carbon dioxide into a subcritical state. Preferably, the temperature sensor 2-5 is electrically connected to the booster 1-1-2, and the pressure of the booster 1-1-2 can be adjusted through the temperature sensor 2-5. The temperature sensor 2-5 can be a DS18B20 model.

[0059] The surface of the cold plate 3 is provided with irregular grooves 3-1. Through experimental verification, the plate and the cold plate 3 are placed on a 50W heat load surface, and a gas-solid mixture is sprayed onto the experimental sample. The temperature change over time is recorded until a steady state is reached. The heat transfer coefficient and thermal resistance are then calculated.

[0060] In the formula, The heat transfer coefficient; This refers to the power or heat exchange capacity of the cold zone. This represents the heat exchange area of ​​the cooling plate; This represents the average temperature difference.

[0061] This is the thermal resistance.

[0062]

[0063] Therefore, it can be seen that the irregular groove 3-1 on the cold plate 3 enhances surface turbulence and increases the time that the gas-solid mixture remains on the cold plate 3.

[0064] It is worth noting that since liquid carbon dioxide mainly comes from the waste emissions of power plants and other production plants, it has no utilization value for these producers and is difficult to handle. Therefore, by storing this waste liquid carbon dioxide in a centralized manner, it can be directly used in this cooling system, making the overall cost lower. At the same time, we can also use secondary recycling to recycle the gas that we ultimately generate and emit into liquid carbon dioxide, thus forming a closed-loop utilization, which makes the overall cost lower and the environmental performance better.

[0065] In use, first connect the storage tank 1-1-1, the booster 1-1-2, and the temperature controller 1-1-3 sequentially via connecting pipes. Then, connect the temperature controller 1-1-3 to the nozzle 1-2-1. Before the nozzle 1-2-1, adjust the pressure of the booster 1-1-2 and the temperature of the temperature controller 1-1-3 to convert liquid carbon dioxide into subcritical carbon dioxide. It is worth noting that the pressure adjustment range of the booster 1-1-2 and the temperature adjustment range of the temperature controller 1-1-3 strictly conform to... Figure 7 The subcritical state range shown; The nozzle 1-2-1 is screwed tightly to the cooling box 2, and then the cooling box 2 and the cold plate 3 are tightly attached to the chip. By adding gaseous material to the nozzle 1-2-1, the material sprayed from the nozzle 1-2-1 is a gas-solid mixture. The gas-solid mixture is sprayed directly onto the cold plate 3 through the cooling box 2. At the moment the gas-solid mixture comes into contact with the cold plate, the latent heat of the solid dry ice sublimates and the sensible heat is carried away by the gaseous carbon dioxide, which causes the cold plate 3 to cool down rapidly, and finally the chip is also cooled down. The temperature sensor on the chip side monitors the chip temperature in real time and continuously feeds back signals to the booster 1-1-2, so that the booster 1-1-2 can adjust the flow rate by adjusting the pressure, and then adjust the cooling rate.

[0066] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A cooling system suitable for server motherboards, characterized in that: include, The cooling assembly (1) includes a reaction element (1-1) and a jet element (1-2) communicating with the reaction element (1-1). The reaction element (1-1) is capable of generating subcritical carbon dioxide, which is ejected from the injection element (1-2); Cooling box (2), the cooling box (2) and the spraying component (1-2) are connected by threads; The cold plate (3) is fixedly connected to the bottom of the cooling box (2), and the cold plate (3) is closely attached to the chip.

2. The cooling system for server motherboards as described in claim 1, characterized in that: The spraying component (1-2) includes a nozzle (1-2-1), an input pipe (1-2-2) disposed on the nozzle (1-2-1), and an air inlet (1-2-3). The input pipe (1-2-2) is connected to the reaction element (1-1), and the air inlet (1-2-3) is connected to the air pump (1-2-4). Gas, which is carbon dioxide, is introduced into the nozzle (1-2-1) through the air pump (1-2-4).

3. The cooling system for server motherboards as described in claim 2, characterized in that: The nozzle (1-2-1) is provided with a first thread (1-2-5).

4. The cooling system for server motherboards as described in claim 3, characterized in that: The cooling box (2) is provided with a second thread (2-1) that mates with the first thread (1-2-5); The nozzle (1-2-1) can be screwed into the cooling box (2), and the nozzle (1-2-1) sprays in the direction of the cooling plate (3).

5. The cooling system for server motherboards as described in claim 4, characterized in that: The cooling box (2) is provided with a vacuum wall (2-2), and the cooling box (2) is provided with the vacuum wall (2-2) on all surfaces except the surface where the cooling plate (3) is located.

6. The cooling system for server motherboards as described in claim 5, characterized in that: The cooling box (2) is provided with an extension plate (2-3) on its inner walls. The length of the extension plate (2-3) is 0.2 times the length of the cooling plate (3).

7. The cooling system for server motherboards as described in claim 6, characterized in that: The cooling box (2) is equipped with an exhaust pipe (2-4).

8. The cooling system for server motherboards as described in claim 7, characterized in that: The chip is equipped with a temperature sensor (2-5), and the temperature sensor (2-5) is electrically connected to the reactant (1-1).

9. The cooling system for server motherboards as described in claim 8, characterized in that: The reaction unit (1-1) includes a storage tank (1-1-1), a booster (1-1-2), and a temperature controller (1-1-3), and the storage tank (1-1-1), the booster (1-1-2), and the temperature controller (1-1-3) are connected by pipes; The booster (1-1-2) and the temperature controller (1-1-3) can convert liquid carbon dioxide into a subcritical state. The temperature sensor (2-5) is electrically connected to the booster (1-1-2), and the pressure of the booster (1-1-2) can be adjusted through the temperature sensor (2-5).

10. The cooling system for server motherboards as described in claim 9, characterized in that: The surface of the cold plate (3) is provided with a shaped groove (3-1).

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