Cooling system and cooling method for electronic device

Abstract

[Problem] To provide a simple and efficient cooling system and cooling method with which the cooling performance of an electronic apparatus is improved. [Solution] This cooling system includes a cooling medium composite 100. The cooling medium composite 100 includes: a non-conductive bag 11 for wrapping an electronic apparatus including a substrate and a heating element mounted on the substrate; a heat sink 21; and a bonding layer 23 joining a rear surface of the heat sink 21 and one surface of the non-conductive bag 11. The bonding layer 23 is formed of a different material bonding film. A first opening 25 is formed in the different material bonding film. The first opening 25 provides a window for thermally connecting the rear surface of the heat sink 21 to one surface of the heating element.

Description

[Technical Field]

[0001] The present invention relates to a cooling system and a cooling method for electronic devices, and in particular to a cooling system and a cooling method for electronic devices that require high performance, stable operation, or low power consumption operation and generate a large amount of heat themselves, such as supercomputers, data centers, artificial intelligence processing systems, quantum computing systems, cryptographic processing systems, and blockchain processing systems. [Background technology]

[0002] In recent years, one of the biggest issues determining the performance limits of computer-related equipment is power consumption, and the importance of research into power efficiency, particularly in supercomputers, is already widely recognized. In other words, speed performance per watt of power (Flops / W) is one indicator for evaluating supercomputers. Furthermore, it is said that more than 30% of the total power consumption of data centers is spent on cooling, and there is a growing demand for reducing power consumption by improving cooling efficiency. Furthermore, due to recent global warming and extreme heat caused by abnormal weather, existing cooling methods are no longer able to cool data centers in the summer, making it urgent to improve the cooling capacity of existing systems. Furthermore, the rapid growth of artificial intelligence processing, the increasing need for encryption processing, the rapid increase in cryptocurrency mining processing, which is a major example of blockchain processing, and the development of the metaverse, which is predicted to grow rapidly, all require an exponential increase in the processing power of data centers and computer systems, and the demand for increased cooling capacity is becoming extremely great.

[0003] Air and liquid cooling methods have traditionally been used to cool supercomputers and data centers. Liquid cooling is generally considered to have better cooling efficiency because it uses a liquid, which has significantly better heat transfer properties than air. For example, the "TSUBAME-KFC" computer built by the Tokyo Institute of Technology achieved 4.50 GFlops / W using a synthetic oil immersion cooling system, earning it the top spot on the "Supercomputer Green500 List" published in November 2013 and June 2014. However, because the coolant uses synthetic oil, which is highly viscous and forms an oil film, it is difficult to completely remove the oil from electronic devices removed from the oil-immersion rack, making electronic device maintenance (specifically, adjustment, inspection, repair, replacement, and expansion) extremely difficult. Furthermore, the synthetic oil used has been reported to corrode electronic circuit boards and gaskets in the cooling system, causing failures and leaking refrigerant, resulting in operational problems.

[0004] On the other hand, immersion cooling systems that use fluorocarbon-based coolants instead of synthetic or mineral oils, which cause the above-mentioned problems, have been proposed. Specifically, these systems use fluorocarbon-based coolants (hydrofluoroether (HFE) compounds known under the trade names "Novec (a trademark of 3M; the same applies hereinafter) 7100," "Novec 7200," and "Novec 7300" from 3M) (see, for example, Patent Documents 1 and 2).

[0005] In addition to these, since 2014, the inventor has been developing a new liquid immersion cooling system and a series of related technologies that directly cools electronic devices by circulating a cooling liquid that is difficult to evaporate and contains a fully fluorinated substance as its main component within the open space of a cooling tank (for example, Patent Document 3).

[0006] However, PFAS (Perfluoroalkyl Substances and Polyfluoroalkyl Substances), which includes all of these fluorocarbon-based coolants, have long been known to have adverse effects on the human body, crops, and the natural environment. In December 2022, the world's largest manufacturer announced that it would completely cease production by the end of 2025, and in Europe, both production and use are expected to be banned by law within a few years. Therefore, there is a need for a new immersion cooling method that does not use any harmful compounds such as PFAS as refrigerants, has superior cooling capacity compared to immersion cooling methods that use PFAS as refrigerants, and is more affordable and can be used widely around the world.

[0007] A typical example of a cooling method that does not use any harmful compounds such as PFAS as a refrigerant is one that can use ordinary water (tap water or industrial water) rather than purified water. Specifically, instead of a heat sink that is attached in direct contact with the top surface of the semiconductor of the CPU (central processing unit), which is the main heat source in computer equipment, this method attaches a "water-cooled block" that contains a flow path for water to pass through inside a copper or aluminum block (for example, Patent Document 4).

[0008] Furthermore, another cooling method that can use water has been proposed, in which a semiconductor chip mounted on a circuit board is stored in a flexible bag, and the bag is immersed in a container filled with water as a cooling liquid. When the bag is filled with water or when the pressure inside the bag is reduced, the bag contracts and deforms due to the pressure difference between the inside and outside of the bag, and the bag is tightly attached to the semiconductor device (for example, Patent Document 5).

[0009] Another cooling method that can utilize water is the natural water-cooled computer, which uses river, lake, ocean, or tap water as a cooling source to directly cool the computer. Specifically, this cooling method involves immersing a computer whose board surface is coated with parylene resin in water (see, for example, Non-Patent Document 1).

[0010] Furthermore, a cooling method has been proposed in which the entire substrate is completely covered with an ultra-nano hydrophobic coating thin film made of silicon compound nanoparticles to create an electronic device with excellent waterproof and moisture-resistant properties, and the device is then immersed in water (e.g., Patent Document 6). [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-187251 [Patent Document 2] Special Publication No. 2012-527109 [Patent Document 3] Patent No. 5853072 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-119345 [Patent Document 5] Patent No. 2804640 [Patent Document 6] U.S. Patent No. 10,717,881 [Non-Patent Document 1] Kazuki Fujiwara et al., Information Processing Society of Japan Research Report High Performance Computing (HPC), "The First Step Towards a Direct Natural Water-Cooled Computer," 2017-HPC-158(5), pp.1-5 (March 1, 2017) URL: http: / / research.nii.ac.jp / ~koibuchi / pdf / ikki-sighpc158.pdf Summary of the Invention [Problem to be solved by the invention]

[0012] The cooling system disclosed in Patent Document 4 uses water as a refrigerant, rather than hazardous substances such as PFAS, as used in Patent Documents 1-3. A water-cooled block mounted on the surface of a semiconductor device mounted in an electronic device has a flowing water path installed within it, which first cools the water-cooled block and then only cools the semiconductor device in direct contact with the block. Therefore, other electronic components and electronic boards that are not in direct contact with the water-cooled block and generate significant heat but still require cooling cannot benefit from the cooling and must be cooled separately using methods such as air cooling. Furthermore, electronic devices used in modern supercomputers and data centers require cooling not only for central processing units (CPUs), but also for graphics processing units (GPUs), high-speed memory, chipsets, power-related components such as field-effect transistors (FETs), electrolytic capacitors, network units, bus switch units, solid-state drives (SSDs), and many other components. These components generate significantly different amounts of heat, making it difficult to adequately cool all of these components using air-cooling, which has inferior cooling capacity compared to liquid-cooling. Typically, a large amount of cooling water must be supplied to a water-cooled block, and because the water-cooled block itself is large and does not have a fin-like shape like a heat sink, it blocks the airflow path for cooling.Furthermore, at least two piping paths are required to supply water to the water-cooled block and then recover it, and these piping paths also block the airflow path for cooling to a certain extent, resulting in extremely low cooling efficiency for objects that are not directly cooled by the water-cooled block.

[0013] Furthermore, the cooling system disclosed in Non-Patent Document 1 completely covers the entire electronic components and electronic board with a thin film of parylene, which does not conduct electricity and is impermeable to water, and then the entire electronic components and electronic board coated with the parylene film are immersed in water or seawater, and the low temperature of the water or seawater that comes into contact with the entire parylene film is used to cool the equipment.

[0014] Similarly, the cooling system disclosed in Patent Document 6 completely covers the entire electronic components and electronic board with an ultra-nano hydrophobic coating film made of silicon compound nanoparticles that are non-conductive and impermeable to water, and then the entire electronic components and electronic board coated with the hydrophobic coating film are immersed in water, and the low temperature of the water that comes into contact with the entire hydrophobic coating film is used to cool the equipment.

[0015] In both the cooling systems of Non-Patent Document 1 and Patent Document 6, all of the electronic components and electronic boards to be cooled are in contact with the refrigerant, water or seawater, via a parylene thin film or a hydrophobic coating thin film. For this reason, when highly efficiently cooling a CPU or other major heat source, the cooling capacity and efficiency are inevitably inferior compared to cooling systems in which the heat sink is directly in contact with the semiconductor surface of a water-cooled block, for example, and the heat sink is directly cooled by a refrigerant such as water.

[0016] Furthermore, with the above-mentioned thin-film coating method, even a slight leakage of the coating can lead to water infiltration into the underlying electronic components and electronic boards, causing irreversible damage due to an electrical short circuit when electricity is applied, making this coating essential. However, since the only way to determine whether an electrical short circuit will occur is through visual inspection or by actually applying electricity to the electronic device, there is always the risk of losing the cooling target. This not only poses a problem when the electronic device is first used, but also leaves the thin coating vulnerable to subsequent breakdown due to deterioration or aging, or even slight contact with other electronic devices, inspection equipment, or tools during maintenance and inspection. Therefore, a dilemma exists when using parylene thin films and hydrophobic coating thin films: while the thin film thickness is desired to increase thermal conductivity from the refrigerant for cooling, a certain thickness is required to prevent leakage and breakdown of the coating to avoid damage to the electronic device.

[0017] Recent electronic substrates and their shapes are becoming increasingly complex in three-dimensional structures and are continuing to shrink in size, so it is expected that establishing a technology to coat them with a flawless thin film will pose considerable technical difficulties, and cooling systems that use these thin film coatings have not yet been widely adopted.

[0018] In addition, these thin film coatings need to be firmly coated by vapor deposition, etc., and electronic components and electronic substrates that have undergone such surface modification are no longer covered by the quality guarantee, so their use must be at one's own risk. Furthermore, even if one wishes to repurpose or resell the components after use, it is extremely difficult to find demand for coated electronic components, so in principle, reuse or resale cannot be expected.

[0019] Incidentally, the water-cooling method disclosed in Patent Document 5 involves storing a semiconductor device in a flexible bag and immersing it in a coolant such as water to achieve cooling. However, like a thin film coating, the bag prevents the surface of the semiconductor device from coming into direct contact with the coolant, which results in a problem of reduced cooling performance.

[0020] As described above, in the case of conventional liquid cooling methods, immersion cooling using PFAS will no longer be possible in the near future, and the cooling capacity is insufficient when using non-PFAS-containing non-conductive liquids such as synthetic oil or silicone. Furthermore, the immersion method using water, which has high cooling capacity, must ensure non-conductivity by thoroughly coating the entire surface with a thin film, but perfect coating formation is becoming increasingly difficult with the advancement of three-dimensional substrate structures and miniaturization of electronic components, hindering its widespread adoption. Furthermore, in conventional liquid cooling systems, the use of a water-cooled block can provide high cooling performance for the CPU, which is the main heat source, but the large water-cooled block and piping required for water cooling make it difficult to provide sufficient cooling for the majority of other electronic components and electronic boards that are cooled by air-cooling. Furthermore, in the conventional liquid cooling method in which a semiconductor device is stored in a flexible bag and cooled by immersing it in water, the bag prevents the surface of the semiconductor device from coming into direct contact with the refrigerant, thereby reducing cooling performance.

[0021] Therefore, an object of the present invention is to provide a cooling system and a cooling method that solve the above-mentioned problems of the conventional technology, improve the cooling performance of electronic devices, and are simple, efficient, inexpensive, and easy to maintain. [Means for solving the problem]

[0022] To solve the above-mentioned problems, one aspect of the present invention provides a cooling system in which an electronic device is immersed in ordinary water (tap water, industrial water, seawater, etc.), a typical example of a coolant with high electrical conductivity and high thermal conductivity, and a heat sink, which is often made of copper or aluminum and thermally connected to an electronic component such as a CPU, which is a major heat source, is directly cooled by the water. In a preferred embodiment of the cooling system according to the present invention, the cooling system includes a cooling medium composite. The cooling medium composite includes a non-conductive bag for encasing the electronic device, which includes a substrate and at least one heat-generating element mounted on the substrate, a heat sink, and a bonding layer connecting the back surface of the heat sink to one side of the non-conductive bag. The bonding layer is formed from a dissimilar material bonding film. A first opening is formed in the dissimilar material bonding film, and the first opening provides a window for thermally connecting the back surface of the heat sink to one side of the at least one heat-generating element.

[0023] In a preferred embodiment of the above cooling system, the bonding layer may provide a watertight connection between the back surface of the heat sink and the outer surface of the non-conductive bag.

[0024] In addition, in a preferred embodiment of the above cooling system, a second opening is formed in the non-conductive bag, and the first opening and the second opening may provide a window for thermally connecting the back surface of the heat sink to one surface of at least one heat generating element.

[0025] Furthermore, in a preferred embodiment of the above cooling system, a raised portion is formed on the back surface of the heat sink, and a second opening is formed in the non-conductive bag, and the first opening and the second opening may provide a window for thermally connecting the raised surface of the raised portion on the back surface side of the heat sink to one surface of at least one heat generating element.

[0026] In addition, in a preferred embodiment of the above cooling system, a third opening having an opening area larger than the back surface area of ​​the heat sink is formed in the non-conductive bag, and the bonding layer may watertightly connect the back surface of the heat sink located within the third opening to the inner surface of the non-conductive bag.

[0027] Furthermore, in a preferred embodiment of the above cooling system, a raised portion is formed on the back surface of the heat sink, and a third opening having an opening area larger than the area of ​​the raised surface on the back surface side of the heat sink is formed in the non-conductive bag, and the bonding layer may watertightly connect the back surface of the heat sink that does not include the raised surface located within the third opening to the inner surface of the non-conductive bag.

[0028] Furthermore, in a preferred embodiment of the cooling system, the heat sink may have a substrate fixing mechanism, and the substrate of the electronic device may be fixed to the substrate fixing mechanism of the heat sink.

[0029] In a preferred embodiment of the cooling system, the substrate fixing mechanism of the heat sink may be two or more screw holes formed at a distance from each other on the rear surface of the heat sink.

[0030] Furthermore, in a preferred embodiment of the above-described cooling system, the cooling medium composite may be configured so that, when a vacuum is drawn inside the non-conductive bag, the inner surface of the non-conductive bag comes into close contact with both surfaces of the substrate and the surfaces of various electronic components mounted on the substrate.

[0031] Additionally, in a preferred embodiment of the cooling system, the non-conductive bag may be configured with a check valve that provides a path for drawing a vacuum and allows the bag to maintain a seal.

[0032] Furthermore, in a preferred embodiment of the cooling system, the non-conductive bag may have a zipper mechanism that allows the electronic device to be placed inside the non-conductive bag when the zipper is open, and that maintains the airtightness of the non-conductive bag when the zipper is closed.

[0033] In addition, in a preferred embodiment of the above cooling system, the non-conductive bag has a heat sealing mechanism, and the heat sealing mechanism may be configured to allow an electronic device to be placed inside the non-conductive bag in an unheat-sealed state and to allow vacuuming after heat sealing, and to maintain the airtightness of the non-conductive bag in a heat-sealed state.

[0034] Furthermore, in a preferred embodiment of the above cooling system, a penetration portion may be formed in the non-conductive bag for passing a power cable, a network communication cable, or a control cable connected to the electronic device, and a sealant provided in the penetration portion may be configured to maintain the airtightness of the non-conductive bag.

[0035] In addition, in a preferred embodiment of the above-mentioned cooling system, the cooling medium composite may further include, within the non-conductive bag, a wireless power supply unit for supplying power to the electronic device and a wireless communication unit for enabling wireless communication between the electronic device and the outside.

[0036] Furthermore, in a preferred embodiment of the cooling system, the cooling system may further include a monitor unit within the non-conductive bag for monitoring the degree of vacuum within the non-conductive bag.

[0037] In addition, in a preferred embodiment of the above cooling system, the cooling system may further include a controller that controls the external vacuum pump to start and draw a vacuum inside the non-conductive bag when the output of the monitor unit indicates a vacuum level below a predetermined threshold.

[0038] Furthermore, in a preferred embodiment of the above cooling system, the cooling system may further include a shutdown unit that stops operation of the electronic device and cuts off power when the output of the monitor unit indicates a vacuum level below a predetermined threshold.

[0039] In addition, according to another aspect of the present invention, there is provided a method for cooling an electronic device, comprising the steps of: preparing a cooling medium composite formed by bonding a heat sink and a non-conductive bag using a dissimilar material bonding film so that the surface of the heat sink is located outside the non-conductive bag; placing the electronic device within the cooling medium composite and thermally connecting one surface of at least one heat generating element included in the electronic device to the back surface of the heat sink through a window formed in the dissimilar material bonding film; sealing the non-conductive bag; and immersing the sealed cooling medium composite in a refrigerant.

[0040] In a preferred embodiment of the cooling method, the step of sealing the non-conductive bag may include the step of drawing a vacuum inside the non-conductive bag. [Effects of the Invention]

[0041] The cooling system of the present invention uses a cooling intermediate composite body including a non-conductive bag for enclosing an electronic device including a substrate and at least one heat-generating element mounted on the substrate, a heat sink, and a bonding layer formed from a dissimilar material bonding film that watertightly connects the back surface of the heat sink to one side of the non-conductive bag. The dissimilar material bonding film also has a first opening that provides a window for thermally connecting the back surface of the heat sink to one side of the heat-generating element when the electronic device is placed in the cooling intermediate composite body. When the cooling intermediate composite body is immersed in a coolant, the coolant directly absorbs heat from the surface of the heat sink, and the heat sink locally and powerfully absorbs heat from the heat-generating element thermally connected to the back surface of the heat sink. Forming the bonding layer from the dissimilar material bonding film here achieves a strong and stable watertight bond between the back surface of the heat sink and one side of the bag. This ensures the overall hermeticity of the cooling intermediate composite body, even if windows are formed in the dissimilar material bonding film or the non-conductive bag. Conventional cooling methods, such as immersing an electronic device in a conductive coolant such as water or seawater, have the problem that the coating or bag used to keep the electronic device watertight from the surrounding coolant impedes heat transfer between the heat-generating element and the coolant. In contrast, the cooling system of the present invention uses the cooling medium composite configured as described above to completely eliminate the heat transfer problems between the heat-generating element and the coolant in conventional techniques, thereby improving the cooling performance of electronic devices. Furthermore, even if windows are formed in the dissimilar material bonded film or the non-conductive bag, the entire cooling medium composite can provide a strong and stable sealed structure. Furthermore, when the non-conductive bag is sealed, a vacuum is drawn inside the non-conductive bag, so that the inner surfaces of the non-conductive bag come into close contact with both sides of the substrate and the surfaces of various electronic components mounted on the substrate. This increases the efficiency of heat removal from the various electronic components, further improving the cooling performance of electronic devices.

[0042] The non-conductive bag can be made of a synthetic resin (e.g., polyethylene, polypropylene, polyester, etc.) that is water-resistant and resistant to relatively low temperatures (e.g., 100°C or higher) and can maintain airtightness (airtightness / watertightness) when sealed. This, combined with the use of a heterogeneous material bonding film that can form a bonding layer through rapid heat-pressing and cooling fixation (alternatively, pressure, ultrasound, electromagnetic waves, light irradiation, etc.), allows for simple, efficient, and inexpensive preparation of a cooling medium composite. Furthermore, when performing maintenance on an electronic device, all that is required is to tear the non-conductive bag of the cooling medium composite and remove the electronic device from the bag. This not only facilitates maintainability, but also provides advantages from the perspective of recycling used electronic devices, as it almost completely prevents the surface of the electronic device from being contaminated by foreign matter.

[0043] The above and other objects and advantages of the present invention will be more clearly understood through the following description of the embodiments, although the embodiments described below are merely examples and the present invention is not limited thereto. [Brief explanation of the drawings]

[0044] [Figure 1A] 1 is a front view showing the configuration of a main part of a cooling system according to an embodiment of the present invention; [Figure 1B] 1 is a side view showing the configuration of a main part of a cooling system according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded view showing an example of a cooling medium composite. [Figure 3A] FIG. 1 is a diagram illustrating an example of a cooling medium composite. [Figure 3B] FIG. 1 is a diagram illustrating an example of a cooling medium composite. [Figure 4] FIG. 2 is a cross-sectional view showing an example of a cooling medium composite. [Figure 5] FIG. 10 is an explanatory diagram showing an example of installing an electronic device in a cooling medium composite. [Figure 6] FIG. 10 is a cross-sectional view showing an example of installing an electronic device in a cooling medium composite. [Figure 7] FIG. 10 is an exploded view showing another example of a cooling medium composite. [Figure 8A] FIG. 10 is a diagram showing another example of a cooling medium composite. [Figure 8B] FIG. 10 is a diagram showing another example of a cooling medium composite. [Figure 9] FIG. 10 is a cross-sectional view showing another example of a cooling medium composite. [Figure 10] 10A and 10B are explanatory diagrams showing another example of installing an electronic device in a cooling medium composite. [Figure 11] FIG. 10 is a cross-sectional view showing another example of installing an electronic device in a cooling medium composite. [Figure 12] FIG. 10 is a bottom view of a heat sink applied to yet another example of the cooling medium composite. [Figure 13] 10 is an explanatory diagram showing yet another example of installing an electronic device in a cooling medium composite. FIG. [Figure 14] FIG. 10 is a cross-sectional view showing yet another example of installing an electronic device in a cooling medium composite. [Figure 15] FIG. 10 is a cross-sectional view showing yet another example of installing an electronic device in a cooling medium composite. [Figure 16] 10A and 10B are diagrams showing a heat sink applied to yet another example of the cooling medium composite. [Figure 17] FIG. 10 is an exploded view showing yet another example of a cooling medium composite. [Figure 18] FIG. 10 is a cross-sectional view showing yet another example of a cooling medium composite. [Figure 19] 10 is an explanatory diagram showing yet another example of installing an electronic device in a cooling medium composite. FIG. [Figure 20] FIG. 10 is a cross-sectional view showing yet another example of installing an electronic device in a cooling medium composite. [Figure 21] FIG. 10 is a bottom view of a heat sink applied to yet another example of the cooling medium composite. [Figure 22] 10 is an explanatory diagram showing yet another example of installing an electronic device in a cooling medium composite. FIG. [Figure 23] FIG. 10 is a cross-sectional view showing yet another example of installing an electronic device in a cooling medium composite. [Figure 24] FIG. 10 is an exploded view showing yet another example of a cooling medium composite. [Figure 25] FIG. 10 is a cross-sectional view showing yet another example of a cooling medium composite. [Figure 26] FIG. 10 is a cross-sectional view showing yet another example of installing an electronic device in a cooling medium composite. [Figure 27] FIG. 10 is a cross-sectional view showing yet another example of installing an electronic device in a cooling medium composite. [Figure 28] FIG. 1 is a diagram illustrating an example of operation of a cooling system. DETAILED DESCRIPTION OF THE INVENTION

[0045] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the cooling system according to the present invention will be described in detail below with reference to the accompanying drawings.

[0046] 1A and 1B, the cooling system 1 includes a cooling medium composite 100. The cooling medium composite 100 includes a non-conductive bag 11 for encasing the electronic device 10, a heat sink 21, and a bonding layer 23 (described later) that connects the back surface of the heat sink 21 to one surface of the non-conductive bag 11. The heat sink refers to a copper or aluminum radiator that can be thermally connected to a heat-generating element of the electronic device. The heat sink may have a number of plate-like or rod-like fins to increase its surface area.

[0047] The non-conductive bag 11 is made of a film made of synthetic resin (e.g., polyethylene, polypropylene, polyester, etc.) that is water-resistant and resistant to relatively low temperatures (e.g., 100°C or higher), and that can maintain airtightness (airtightness / watertightness) when sealed. One side of the non-conductive bag 11 is provided with a zipper mechanism 20. The zipper mechanism 20 is configured so that the electronic device 10 can be placed inside the non-conductive bag 11 when the zipper is open, and so that the airtightness of the non-conductive bag 11 is maintained when the zipper is closed. In addition, a check valve 19 is provided on one side of the non-conductive bag 11. The check valve 19 provides a path for drawing a vacuum inside the non-conductive bag 11, and maintains the airtightness during and after the vacuum is drawn.

[0048] The electronic device 10 includes a substrate 31, at least one heating element 33 (e.g., a CPU, as shown in FIG. 5 and elsewhere) mounted on the substrate 31, and various electronic components 35 such as an electrolytic capacitor. One end of each of a network communication cable 36 and a power cable 37 is connected via a connector to the electronic device 10 placed in the non-conductive bag 11. The network communication cable 36 and the power cable 37 each pass through a penetration formed on one surface of the non-conductive bag 11. Because a sealant 17 is provided in the penetration, the other end of each of the network communication cable 36 and the power cable 37 can be connected to network equipment and power distribution equipment outside the non-conductive bag 11 while maintaining the airtightness of the non-conductive bag 11.

[0049] FIG. 2 shows the components of the cooling medium composite 100, namely, the non-conductive bag 11, the heat sink 21, and the bonding layer 23, in an exploded state. FIG. 3A shows the cooling medium composite 100 from the outer surface 11A of the non-conductive bag 11, FIG. 3B shows the cooling medium composite 100 from the inner surface 11B of the non-conductive bag 11, and FIG. 4 shows a cross section taken along line AA in FIG. 3A. The bonding layer 23 connects the back surface of the heat sink 21 to the outer surface of the non-conductive bag 11, and in particular, the bonding layer 23 is formed from a dissimilar material bonding film. The dissimilar material bonding film that forms the bonding layer 23 has a first opening 25 formed therein. The first opening 25 provides a window for thermally connecting the back surface 21B of the heat sink 21 to one surface of the heating element 33, as described below. The size of the dissimilar material bonded film is preferably the same as or slightly larger than the size of the heat sink 21, and the size of the first opening 25 corresponding to the window is preferably the same as or slightly larger than the size of the heating element 33. It is preferable that a second opening 15 is also formed in the non-conductive bag 11. In this case, the size of the second opening 15 formed in the non-conductive bag 11 may be the same as the size of the first opening formed in the dissimilar material bonded film, and together with the first opening 23, provides a common window for thermally connecting the back surface of the heat sink 21 to one surface of the heating element 33.

[0050] An example of a dissimilar material bonding film for forming the bonding layer 23 is the "Metaseal" (a product name of Fujimori Kogyou Co., Ltd.) series. This dissimilar material bonding film is formed into a film of uniform thickness, so that the bonding layer 23 for bonding the heat sink 21 and the non-conductive bag 11 can be formed by sandwiching the film between the back surface 21B of the heat sink 21 and the outer surface 11A of the non-conductive bag 11 and then thermocompression bonding. A heat press or an iron-type heater can be used for thermocompression bonding, and the bonding process of the heat sink 21 and the non-conductive bag 11 can be completed easily and in a short time (several seconds or more). Note that the method for forming the bonding layer 23 is not limited to thermocompression bonding, and various methods, such as pressure, ultrasonic waves, electromagnetic waves, and light irradiation, can also be used.

[0051] By forming the bonding layer 23 from a dissimilar material bonding film, it is possible to achieve surface bonding between the back surface 21B of the heat sink 21 and the outer surface 11A of the non-conductive bag 11 with a uniform film thickness and without variations in adhesive strength. This makes it suitable for use in firmly bonding the heat sink and the bag.

[0052] Another example of a dissimilar material bonded film that forms the bonding layer 23 is "WelQuick" (a Resonac product name) manufactured by Resonac Corporation. This dissimilar material bonded film utilizes the solid-liquid phase change of the film materials, allowing the bonding process to be completed in a short time (a few seconds). It also allows for reheating after bonding to allow for peeling and re-adhesion. This makes it easy to recover the cooling medium composite 100 of a cooling system after a certain period of use and peel the heat sink 21 from the non-conductive bag 11, resulting in high resource reusability.

[0053] Here, the dissimilar material bonding film can be preferably a pre-formed sheet or film that can be cut and used. However, this is not limited thereto. For example, if a certain environment is established in which various conditions, including the film thickness and shape, can be appropriately controlled, a bonding layer 23 formed from the dissimilar material bonding film can be obtained starting with a liquid or gel adhesive material. Specifically, as an example, a mold is first placed on the back surface of the heat sink (or the back surface of the heat sink and the inner surface of the non-conductive bag) and filled with the liquid or gel adhesive material, thereby forming a coating of the adhesive material with the desired shape (i.e., a shape with a central window) and volume on the back surface of the heat sink (or the back surface of the heat sink and the inner surface of the non-conductive bag). Next, with the coating of the adhesive material in contact with the back surface of the heat sink and the outer surface of the non-conductive bag (or the back surface of the heat sink and the inner surface of the non-conductive bag), the coating of the adhesive material can be solidified by methods such as thermocompression, pressure, ultrasound, electromagnetic waves, or light irradiation. By doing so, a bonding layer formed of a dissimilar material bonding film can be obtained starting from a liquid or gel adhesive material.

[0054] FIG. 5 shows an example of installing an electronic device 10 in the cooling medium composite 100, and FIG. 6 shows a cross section taken along the line BB in FIG. 5 . As shown in FIG. 5 , the electronic device 10 is installed in the cooling medium composite 100. At this time, as shown in FIG. 6 , one surface of the heating element 33 is in surface contact with the back surface 21B of the heat sink 21 through windows formed in the non-conductive bag 11 and the dissimilar material bonding film 23, thereby providing thermal connection. To ensure surface contact and thermal connection, it is preferable to fill the minute gap between the one surface of the heating element 33 and the back surface 11B of the heat sink 21 with thermally conductive grease 34. After installing the electronic device 10 in the cooling medium composite 100, the zipper mechanism of the non-conductive bag 11 is closed, and then the non-conductive bag 11 is evacuated via the check valve 19. By evacuating, the inner surface of the non-conductive bag can be in close contact with both surfaces of the board and the surfaces of various electronic components mounted on the board.

[0055] FIG. 28 shows an example of the operation of the cooling system 1. A cooling tank 3 contains a sufficient amount of coolant 4 to immerse the cooling medium composite 100. The coolant 4 may be ordinary water (tap water, industrial water, seawater, etc.). A pipe 5 connected to the cooling tank 3 provides a path for discharging the coolant heated in the cooling tank 3 and returning the coolant cooled by a heat exchanger (not shown) to the cooling tank 3. In the cooling medium composite 100 immersed in the coolant 4, the coolant 4 directly absorbs heat from the surface of the heat sink 21, and the heat sink 21 locally and powerfully absorbs heat from the heat-generating element 33 thermally connected to the back surface 21B of the heat sink 21. Conventional cooling methods have had the problem that the coatings or bags covering electronic devices or semiconductor devices inhibit heat transfer between the heat-generating element and the coolant. This method solves this problem and improves the cooling performance of electronic devices. In addition, by drawing a vacuum inside the non-conductive bag 11 and bringing the inner surface of the non-conductive bag 11 into close contact with both sides of the substrate 31 and the surfaces of the various electronic components 35 mounted on the substrate 31, the efficiency of removing heat from the various electronic components 35 can be increased, and the cooling performance of the electronic device 100 can be further improved.

[0056] Next, other examples of the cooling medium composite will be described with reference to Figures 7 to 27. Note that the same reference numerals are used for the same parts as in Figures 1A to 6. FIG. 7 is an exploded view of another example of a cooling medium composite, showing the non-conductive bag 71, heat sink 21, and bonding layer 83, which are components of the cooling medium composite 200, in an exploded state. FIG. 8A shows the cooling medium composite 200 from the outer surface 71A of the non-conductive bag 71. FIG. 8B shows the cooling medium composite 200 from the inner surface 71B of the non-conductive bag 71. FIG. 9 shows the CC cross section of FIG. 8A. The bonding layer 83 connects the back surface of the heat sink 21 to the inner surface of the non-conductive bag 11 and is formed from a dissimilar material bonding film. The dissimilar material bonding film forming the bonding layer 83 has a first opening 85, which provides a window for thermally connecting the back surface 21B of the heat sink 21 to one surface of the heat-generating element 33. The size of the dissimilar material bonding film must be larger than the size of the heat sink 21. On the other hand, the size of the first opening 85 corresponding to the window is preferably the same as or slightly larger than the size of the heating element 33. A third opening 75 is formed in the non-conductive bag 71, and the size of the third opening 75 is preferably the same as or slightly larger than the size of the heat sink 21. A dissimilar material bonding film is placed so as to span between the back surfaces 21B of the heat sinks 21 and the inner surfaces 71A of the non-conductive bags 71 adjacent to each other, and is then heated and pressed to form a bonding layer 83 that bonds the heat sink 21 and the non-conductive bag 71 with a bridge.

[0057] Fig. 10 shows an example of installing an electronic device 10 in the cooling medium composite 200, and Fig. 11 shows a DD cross section of Fig. 10. As shown in Fig. 10, the electronic device 10 is installed in the cooling medium composite 200. At this time, as shown in Fig. 11, one surface of the heat generating element 33 is in surface contact with the rear surface 21B of the heat sink 21 through a window formed in the dissimilar material bonding film 83, and is thermally connected. A cooling system including the cooling medium composite 200 configured in this manner has the same effects as the cooling system including the cooling medium composite 100 described above.

[0058] 12 to 14 are diagrams showing yet another example of a cooling medium composite, and cooling medium composite 300 differs from cooling medium composite 100 shown in FIGS. 2 to 6 in that heat sink 41 has a substrate fixing mechanism 43. The substrate fixing mechanism 43 may be, for example, two or more screw holes formed at a distance from each other on the rear surface 41B of heat sink 41. In the example shown in FIG. 12, screw holes are formed in the four corners of the rear surface 41B of heat sink 41.

[0059] FIG. 13 shows an example of installing an electronic device 50 in the cooling medium composite 300, and FIG. 14 shows an E-E cross section of FIG. 13 . As shown in FIG. 13 , a through-hole 53 is also formed in a substrate 51 of the electronic device 50 at a position corresponding to the screw hole 43. When installing the electronic device 50 in the cooling medium composite 300, a screw 55 is passed through the through-hole 53 in the substrate 51, penetrates the non-conductive bag 11 and the bonding layer 23, and engages with the screw hole 43 in the heat sink 41. A cooling system including the cooling medium composite 300 configured in this manner strengthens the bond between the electronic device 50 and the heat sink 41 of the cooling medium composite 300. This is particularly advantageous, for example, when installing a large and heavy electronic device, or when the surface on which the electronic device 50 and the heat sink 41 of the cooling medium composite 300 are bonded is not horizontal but vertical or inclined. It goes without saying that a cooling system including the cooling medium composite 300 has the same effects as the cooling system including the cooling medium composite 100 described above.

[0060] Figure 15 is a diagram showing yet another example of a cooling medium composite. Cooling medium composite 400 has a similar configuration to cooling medium composite 200 shown in Figures 7 to 11. However, it differs from cooling medium composite 200 in that the heat sink 41 of cooling medium composite 400 has a substrate fixing mechanism 43 shown in Figure 12. A cooling system including cooling medium composite 400 configured in this manner has the same effects as the cooling system including cooling medium composite 300 described above.

[0061] 16 to 20, a further example of the cooling medium composite will be described. The cooling medium composite 500 uses a heat sink 81 having the structure shown in FIG. 16. That is, the heat sink 81 has a rectangular raised portion 82 formed near the center of its rear surface 81B. The raised portion 82 has a flat raised surface 82B. In FIG. 16, (A) shows a front view of the heat sink 81, (B) shows a central cross-sectional view, and (C) shows a bottom view.

[0062] FIG. 17 shows the non-conductive bag 11, heat sink 81, and bonding layer 23, which are components of the cooling medium composite 500, in an exploded state. FIG. 18 shows a central cross section of the cooling medium composite 500. The bonding layer 23 is a layer that connects the back surface 81B (not including the raised surface 82B) of the heat sink 81 to the outer surface of the non-conductive bag 11. In particular, the bonding layer 23 is formed from a dissimilar material bonding film. The dissimilar material bonding film that forms the bonding layer 23 has a first opening 25 formed therein. As described below, the first opening 25 provides a window for thermally connecting the raised surface 82B on the back surface of the heat sink 81 to one surface of the heat generating element 63 of the large-scale semiconductor device 32. The size of the dissimilar material bonding film is preferably the same as or slightly larger than the size of the heat sink 81. The size of the first opening 25, which corresponds to the window, is preferably the same as or slightly larger than the size of the raised surface 82B of the raised portion 82 on the back surface of the heat sink 81. It is preferable that a second opening 15 is also formed in the non-conductive bag 11. In this case, the size of the second opening 15 formed in the non-conductive bag 11 may be the same as the size of the first opening formed in the dissimilar material bonding film, and together with the first opening 23, provides a common window for thermally connecting the raised surface 82B on the back side of the heat sink 21 to one surface of the heating element 63.

[0063] Fig. 19 shows an example of installing an electronic device 60 in a cooling medium composite 500, and Fig. 20 shows an FF cross section of Fig. 19. As shown in Fig. 19, the electronic device 60 particularly has a large semiconductor device 32 mounted on a substrate 61, and the large semiconductor device 32 includes a heating element 63 with a relatively large area near its center. In addition, a semiconductor frame 65 (sometimes called a stiffener) is provided so as to surround the rectangular edge of the large semiconductor device 32. The semiconductor frame 65 is a reinforcing material, and the surface of the semiconductor frame 65 may be higher than the surface of the large semiconductor device 32.

[0064] The electronic device 60 is placed in the cooling medium composite 500. At this time, as shown in FIG. 20 , one surface of the heating element 63 is in surface contact with the raised surface 82B of the raised portion 82 on the back side of the heat sink 81 through the windows formed in the non-conductive bag 11 and the dissimilar material bonding film 23, thereby achieving thermal connection. Because the raised surface 82B of the raised portion 82 on the back side of the heat sink 81 is provided, such connection is possible even if the surface of the large semiconductor device 32, i.e., the surface of the heating element 63, is lower than the surface of the semiconductor frame 65. To ensure surface contact and thermal connection, it is preferable to fill the minute gap between the one surface of the heating element 63 and the raised surface 82B of the raised portion 82 on the back side of the heat sink 81 with thermally conductive grease 34.

[0065] 19 and 20 show an example in which the large-sized semiconductor device 32 includes one heat generating element 63, but it goes without saying that the large-sized semiconductor device 32 may include two or more heat generating elements. In this case, the raised surface 82B of one raised portion 82 on the back surface side of the heat sink 81 may be in surface contact with and thermally connected to each of the two or more heat generating elements.

[0066] 21 to 23 show yet another example of the cooling medium composite, and cooling medium composite 600 differs from cooling medium composite 500 shown in FIGS. 16 to 20 in that heat sink 81 has substrate fixing mechanism 43. Substrate fixing mechanism 43 may be, for example, two or more screw holes formed apart from each other on rear surface 81B, which does not include raised surface 82B, of the rear surface side of heat sink 81. In the example shown in FIG. 21, screw holes are formed in the four corners of rear surface 81B of heat sink 81.

[0067] FIG. 22 shows an example of installing an electronic device 60 in the cooling medium composite 600, and FIG. 23 shows a cross section taken along the line GG in FIG. 22. As shown in FIG. 22, a through-hole 53 is formed in the substrate 61 of the electronic device 60 at a position corresponding to the screw hole 43. When installing the electronic device 60 in the cooling medium composite 600, a screw 55 is passed through the through-hole 53 in the substrate 51, penetrates the non-conductive bag 11 and the bonding layer 23, and engages with the screw hole 43 in the heat sink 81. A cooling system including the cooling medium composite 600 configured in this manner strengthens the bond between the electronic device 60 and the heat sink 81 of the cooling medium composite 600. This is particularly advantageous, for example, when installing a large and heavy electronic device, or when the surface on which the electronic device 60 and the heat sink 81 of the cooling medium composite 600 are bonded is not horizontal but vertical or inclined. Needless to say, a cooling system including the cooling medium composite 600 has the same effects as the cooling system including the cooling medium composite 500 described above.

[0068] Another example of the cooling medium composite will be described with reference to FIGS. 24 to 26. FIG. 24 is an exploded view showing another example of the cooling medium composite, illustrating the non-conductive bag 71, heat sink 81, and bonding layer 83, which are components of the cooling medium composite 700, in an exploded state. FIG. 25 shows a central cross section of the cooling medium composite 700. The bonding layer 83 is a layer that connects the back surface 81B, which does not include the raised surface 82B on the back side of the heat sink 21, to the inner surface of the non-conductive bag 11. The bonding layer 83 is formed from a dissimilar material bonding film. The dissimilar material bonding film that forms the bonding layer 83 has a first opening 85 formed therein, which provides a window for thermally connecting the raised surface 82B on the back side of the heat sink 21 to one surface of the heat generating element 33 of the large-scale semiconductor device 32. The size of the dissimilar material bonding film must be larger than the size of the heat sink 81. On the other hand, the size of the first opening 85 corresponding to the window is preferably similar to or slightly larger than the size of the raised surface 82B of the raised portion 82 on the back surface side of the heat sink 81. A third opening 75 is formed in the non-conductive bag 71, and the size of the third opening 75 is preferably similar to or slightly larger than the size of the heat sink 81. A dissimilar material bonding film can be placed so as to span between the back surfaces 81B, not including the raised surfaces 82B on the back surface sides of the adjacent heat sinks 81, and the inner surface of the non-conductive bag 71, and then heat-pressed to form a bonding layer 83 that bonds the heat sinks 81 and the non-conductive bag 71 with a bridge.

[0069] 26 shows a central cross section of an example in which electronic device 60 is installed in cooling medium composite 700. When electronic device 60 is installed in cooling medium composite 700, one surface of heat generating element 63 of large semiconductor device 32 is in surface contact with and thermally connected to raised surface 82B on the back side of heat sink 21 through a window formed in dissimilar material bonding film 83. A cooling system including cooling medium composite 700 configured in this manner has the same effects as the cooling system including cooling medium composite 500 described above.

[0070] Figure 27 is a diagram showing yet another example of a cooling medium composite. Cooling medium composite 800 has a similar configuration to cooling medium composite 700 shown in Figures 24 to 26. However, it differs from cooling medium composite 700 in that the heat sink 81 of cooling medium composite 800 has the substrate fixing mechanism 43 shown in Figure 21. A cooling system including cooling medium composite 800 configured in this manner has the same effects as the cooling system including cooling medium composite 600 described above.

[0071] Referring again to FIG. 28 , an example of operation of the cooling system 1 will be described in more detail. Two or more cooling medium composites 100 may be immersed in the coolant 4 contained in the cooling tank 3. A top plate 3A may be installed in the cooling tank 3 to reduce evaporation of the coolant 4. Furthermore, the cooling medium composite 100 of the cooling system 1 may include, in the non-conductive bag 11, a wireless power supply unit (not shown) for supplying power to the electronic device 10, instead of a power cable, and may also include, in the non-conductive bag 11, a wireless communication unit (not shown) for enabling wireless communication between the electronic device 100 and the outside, instead of a network communication cable. In this case, a through hole for passing the cable and a sealant provided in the through hole are not required, and the effort required to ensure and maintain the airtightness of the through hole can be saved.

[0072] The cooling medium composite 100 of the cooling system 1 may also include a monitor unit 120 in the non-conductive bag 11 for monitoring the degree of vacuum within the non-conductive bag 11. The cooling system 1 may further include a controller 160 that controls the activation of an external vacuum pump 7 to evacuate the non-conductive bag 11 via an air tube 9 connected to a check valve 19 when the output of the monitor unit 120 indicates a degree of vacuum below a predetermined threshold. An operator may also be able to visually check the output value of the monitor unit 120 and the operating status of the controller 160 on a computer (PC) 180 communicatively connected to the controller 160. This allows the degree of vacuum to be monitored and vacuuming to be performed autonomously as needed, thereby maintaining the near-vacuum sealed structure of the cooling medium composite 100 for a long period of time. Additionally or alternatively, the cooling system 1 may include a shutdown unit 140 that stops operation of the electronic device 10 and cuts off power when the output of the monitor unit 120 indicates a degree of vacuum below a predetermined threshold. In the unlikely event that the vacuum in the cooling medium composite 100 is lost, the surrounding coolant may seep into the cooling medium composite 100, causing an electrical short circuit and potentially irreversible damage to the entire electronic device 100. The shutdown unit 140 can prevent such a problem from occurring by instantly stopping the operation and power supply to the electronic device 100.

[0073] Note that various modifications of the components are possible in the above-described embodiment of the cooling system. For example, instead of a zipper mechanism, the non-conductive bag may have a heat-sealing mechanism. The heat-sealing mechanism may be configured to allow the placement of an electronic device inside the non-conductive bag in an unheat-sealed state, allow vacuuming after heat-sealing, and maintain the airtightness of the non-conductive bag in a heat-sealed state. When two or more heating elements are mounted on the substrate of the electronic device, the size and / or number of the heat sinks, the size and / or number of the dissimilar material bonding films forming the bonding layer, the size and / or number of windows formed in the films, and the position, size and / or number of windows formed in the non-conductive bag may be appropriately determined taking into consideration the positions where the two or more heating elements are mounted on the substrate, the sizes of the heating elements, the expected maximum heat generation, etc. [Industrial Applicability]

[0074] The present invention can be widely applied to cooling systems and cooling methods that efficiently cool electronic devices by immersing them in a conductive coolant such as ordinary water, tap water, or seawater. [Explanation of symbols]

[0075] 1. Cooling system 3 Cooling tank 3A Top plate 4 Coolant (water) 5 Piping 7. Vacuum pump 9 Air Tube 10, 50, 60, electronic equipment 100, 200, 300, 400, 500, 600, 700, 800 Cooling Median Complex 120 Vacuum monitor unit 140 Shutdown Unit 160 Control Unit 180 Computers (PCs) 11, 71 Non-conductive bags 11A, 71A External surface 11B, 71B inner surface 15, 85 Window (second opening) 17 Sealing material 19 Check valve 20 Zipper mechanism 21, 41, 81 Heatsink 21B, 41B, 81B Backside of heat sink 82 elevated portion 81B back 82B Raised surface 23, 83, bonding layer 25, 85 Window (first opening) 31, 51, 61 PCB 32 Large-scale semiconductor devices 33, 63 Heating element (CPU) 34 Thermal grease 35 Electronic Components 36 Network communication cable 37 Power Cable 43 Screw holes (board fixing mechanism) 53 through hole 55 screws 65 Stiffener 75 Window (third opening)

Claims

1. A cooling system for cooling an electronic device by immersing it in a cooling liquid, The cooling system includes a cooling mediator complex; The cooling medium complex is a non-conductive bag for enclosing an electronic device including a substrate and at least one heating element mounted on the substrate; A heat sink; a joining layer that connects the back surface of the heat sink and one surface of the non-conductive bag in a watertight manner; Including, the bonding layer is formed from a dissimilar material bonding film, a first opening is formed in the dissimilar material bonding film, and the first opening provides a window for thermally connecting the back surface of the heat sink to one surface of the at least one heat generating element; Cooling system.

2. The cooling system of claim 1 , wherein the bonding layer provides a watertight connection between the back surface of the heat sink and an outer surface of the non-conductive bag.

3. 3. The cooling system of claim 2, wherein a second opening is formed in the non-conductive bag, the first opening and the second opening providing a window for thermally connecting the back surface of the heat sink to the one surface of the at least one heat generating element.

4. 3. The cooling system of claim 2, wherein a raised portion is formed on a back surface of the heat sink, and a second opening is formed in the non-conductive bag, the first opening and the second opening providing a window for thermally connecting a raised surface of the raised portion on the back surface side of the heat sink to one side of the at least one heat generating element.

5. 2. The cooling system of claim 1, wherein the non-conductive bag has a third opening having an opening area larger than a rear surface area of ​​the heat sink, and the bonding layer watertightly connects the rear surface of the heat sink located within the third opening to an inner surface of the non-conductive bag.

6. 2. The cooling system of claim 1, wherein a raised portion is formed on the back surface of the heat sink, a third opening having an opening area larger than the area of ​​the raised surface of the raised portion on the back surface side of the heat sink is formed in the non-conductive bag, and the bonding layer watertightly connects the back surface of the heat sink that does not include the raised surface located within the third opening to the inner surface of the non-conductive bag.

7. The cooling system according to claim 1 , wherein the heat sink has a substrate fixing mechanism, and the substrate of the electronic device is fixed to the substrate fixing mechanism of the heat sink.

8. The cooling system according to claim 7 , wherein the substrate fixing mechanism of the heat sink is two or more screw holes formed at a distance from each other on the rear surface of the heat sink.

9. 2. The cooling system according to claim 1, wherein the cooling medium composite is configured such that, when a vacuum is drawn inside the non-conductive bag, the inner surfaces of the non-conductive bag come into close contact with both sides of the substrate and surfaces of various electronic components mounted on the substrate.

10. 10. The cooling system of claim 9, wherein the non-conductive bag is configured with a check valve that provides a path for drawing a vacuum and allows the bag to maintain a seal.

11. 10. The cooling system of claim 9, wherein the non-conductive bag has a zipper mechanism configured to allow placement of the electronic device inside the non-conductive bag in a zipper-open state and to maintain a seal of the non-conductive bag in a zipper-closed state.

12. 10. The cooling system of claim 9, wherein the non-conductive bag has a heat sealing mechanism that is configured to allow the electronic device to be placed inside the non-conductive bag in an unheat-sealed state and to allow vacuuming after heat sealing, and to maintain the airtightness of the non-conductive bag in a heat-sealed state.

13. 10. The cooling system of claim 9, wherein the non-conductive bag has a through hole formed therein for passing a power cable, a network communication cable, or a control cable connected to an electronic device, and a sealant provided in the through hole is configured to maintain the airtightness of the non-conductive bag.

14. 10. The cooling system according to claim 9, wherein the cooling medium composite further includes, within the non-conductive bag, a wireless power supply unit for supplying power to the electronic device and a wireless communication unit for enabling wireless communication between the electronic device and an outside.

15. The cooling system of claim 9 , wherein the cooling medium composite further includes a monitor unit disposed within the non-conductive bag for monitoring a degree of vacuum within the non-conductive bag.

16. 16. The cooling system of claim 15, further comprising an exhaust controller that controls, when the output of the monitor unit indicates a vacuum level below a predetermined threshold, to activate a vacuum pump disposed outside the cooling medium composite to draw a vacuum inside the non-conductive bag.

17. 16. The cooling system of claim 15, further comprising a shutdown unit that stops operation of the electronic equipment and cuts off power when the output of the monitor unit indicates a vacuum level below a predetermined threshold.

18. A method for cooling an electronic device, comprising: A step of preparing a cooling medium composite including a non-conductive bag for enclosing an electronic device including a substrate and at least one heat generating element mounted on the substrate, a heat sink, and a bonding layer that connects a back surface of the heat sink and one surface of the non-conductive bag in a watertight manner, the bonding layer being formed from a dissimilar material bonding film; placing the electronic device in the cooling medium composite, and thermally connecting one surface of the at least one heat generating element to a rear surface of the heat sink through a window formed in the dissimilar material bonding film; sealing the non-conductive bag; Immersing the sealed cooling medium composite in a coolant; A method comprising:

19. 20. The method of claim 18, wherein the bonding layer provides a watertight connection between the back surface of the heat sink and an outer surface of the non-conductive bag, or a watertight connection between the back surface of the heat sink and an inner surface of the non-conductive bag.

20. 20. The method of claim 18, wherein sealing the non-conductive bag comprises drawing a vacuum within the non-conductive bag.

Images