Cold plates and systems for cooling electronic devices

Abstract

To provide an improved liquid coolant-based system having high performance and efficiency.SOLUTION: A cold plate heat sink hybrid device 6 comprises a base 27, an upper housing 22, a cold plate internal volume 23, and a receptacle part 15. The base 27 is adapted to be mounted to an electronic device or component by means of mounting holes 28 formed in the base 27. An upper pin 21 is provided in the receptacle part 15, and a lower pin 26 is provided in the cold plate internal volume 23. An interface between the cold plate internal volume 23 and the receptacle part 15 defines a heat transfer zone between a primary liquid coolant and a secondary liquid coolant, and the secondary liquid coolant cools the heat transfer zone and the pin 21 within the receptacle part 15.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] Field of Disclosure The present disclosure relates to cold plates and systems for cooling electronic devices comprising such cold plates.

Background Art

[0002] Background of the Invention (Information technology or IT for short) Computers, servers, and other devices used for data processing typically comprise a printed circuit board (PCB). On these PCBs are small devices called integrated circuits (ICs), which may include a central processing unit (CPU), an application specific integrated circuit (ASIC), a graphics processing unit (GPU), a random access memory (RAM), and the like. All of these electronic components or devices generate heat during use. To maximize the performance of IT and to maintain the contents at an optimal temperature, heat must be transferred. These considerations also apply to other types of electronic devices or systems.

[0003] IT is usually housed within a case, enclosure, or housing. For example, in a server, this enclosure may be called a server chassis. Server chassis typically conform to some industry standards that specify the height of each chassis, called 1RU (one rack unit) or 1OU (one open unit), which are also abbreviated as 1U or 1OU. The smaller of the two main standards is 1RU / 1U with a height of 44.45 mm or 1.75 inches. Such units may be called "blade" servers in terms of shape and style, but such server chassis may not need to be slotted or plugged into, for example, a backplane.

[0004] Different server products can utilize multiple RUs / OUs in a single chassis; for example, a 2U chassis uses two rack units. The size of each server chassis is typically kept to a minimum to maximize computing power per server rack (a server rack is the main housing into which server chassis are added).

[0005] Typically, electronic components or devices used in or within IT systems are cooled using air. This usually involves some type of heat sink, where fins or similar elements are positioned in direct contact with the chip surface or with the TIM (Thermal Interface Material) between the two components. In addition to the heat sink, each enclosure uses a series of fans to draw air through the enclosure, remove heat from the heat sink, and expel it from the chassis. This type of heat sink is used in combination with server equipment-side cooling, such as air conditioning. This cooling method is not particularly efficient, has high running costs, and requires a large amount of space to manage the air used for cooling.

[0006] This method of cooling IT is used almost exclusively in mass-produced IT and server equipment. However, more recently, the limitations of cooling devices with air have suppressed the peak performance of heat-generating chips. As the size of technology halves every few years for the same performance (as exemplified by Moore's Law), the heat generated by the chip increases as the footprint of its components decreases. This has led to an increase in the size and complexity of heatsinks designed for air cooling. As a result, the required server chassis size is often larger, and therefore the computing power within a single rack decreases.

[0007] Liquid cooling can be used as an alternative to air cooling. Liquid cooling can, in some cases, provide more efficient heat transfer from electronic components or devices, and therefore greater cooling power. These liquids include, to name a few, dielectric fluids, mineral oil, and water. Several existing techniques using liquid cooling are known. For example, International Publication 2018 / 096362, jointly transferred with this disclosure, describes an immersion liquid cooling technique in which a primary liquid coolant, typically a dielectric liquid, is pumped within a sealed chassis so that it remains inside. A heat exchanger is also located within the chassis and transfers heat from the primary liquid coolant to a secondary liquid coolant that flows outside the chassis and (may be shared between multiple chassis) is typically water or a water-based system (which is advantageous as it has a high specific heat capacity).

[0008] Building upon this, International Publication 2019 / 048864, also transferred in common with this disclosure, describes several types of heatsinks that may be mounted on, around, or adjacent to an electronic device, or on or around an electronic device. The heatsink defines an internal volume for accumulating and holding a primary liquid coolant adjacent to one or more electronic devices. As the primary liquid coolant flows through the chassis (by pressure and / or convection), it is directed into the internal volume of the heatsink, improving the cooling of the electronic device (e.g., an IC or power supply unit that becomes particularly hot during operation). The primary liquid coolant then flows out of the internal volume of the heatsink (e.g., by overflow and / or by flowing through holes in the volume) and collects with the remaining primary liquid coolant in the chassis to cool other electronic devices (e.g., other components or ICs otherwise mounted on the PCB or in the chassis). The primary liquid coolant is again cooled by a heat exchanger in the chassis, and the heat is transferred to a secondary liquid coolant. This method allows the height of the primary liquid coolant within the chassis to be kept low, ensuring it remains below the height of the primary liquid coolant within the heatsink's internal volume. This creates a multi-level (height) liquid coolant, reducing the amount of liquid coolant required and enabling efficient single-phase (i.e., liquid-phase only) cooling of electronic devices. Since primary liquid coolants are expensive, difficult to contain, and potentially contaminated, this method offers significant advantages in terms of cost and complexity reduction.

[0009] In a different approach, U.S. Patent No. 7,724,524 describes a hybrid immersion cooling system for computing systems in which a blade server chassis houses electronic components. A cold plate is coupled to some of the electronic components for cooling, and pipes within the chassis supply coolant to the cold plate from the outside of the chassis. After passing through the cold plate (or multiple cold plates), the coolant is returned to the outside of the chassis. Another coolant is supplied into the chassis to immerse the remaining electronic components and the cold plate. The chassis is made liquid-tight to prevent leakage of this coolant. The immersion coolant is cooled by the coolant flowing through the cold plate. Making the server environment quieter and more energy-efficient is identified as a key consideration in this document.

[0010] It would be desirable to provide improved liquid coolant-based systems with high performance and efficiency. [Overview of the project] [Means for solving the problem]

[0011] Summary of Disclosure Against this backdrop, the cold plate described in claim 1 and the system for cooling electronic devices described in claim 8 are provided. Further preferred and / or advantageous features are identified in the dependent claims and the remainder of this disclosure. Methods for manufacturing and / or operating cold plates and / or systems for cooling electronic devices are also conceivable, which have steps corresponding to the structural features of the cold plates and / or systems.

[0012] A cold plate having an external receptacle is provided. The external receptacle defines a volume that can receive, accumulate, and / or hold primary liquid coolant (e.g., through a nozzle) to provide heat transfer between primary liquid coolant outside the cold plate and secondary liquid coolant flowing through the cold plate (e.g., in a conventional manner). The primary and secondary liquid coolants are advantageously separate and isolated and physically isolated from each other (although thermally coupled). Such a method may be significantly more efficient than those described earlier.

[0013] The primary liquid coolant may be dielectric, and / or the secondary liquid coolant may be aqueous. The body of the cold plate is thermally conductive, allowing heat transfer from the electronic device to which the cold plate is mounted or to an adjacent electronic device to which the cold plate is mounted, to the secondary liquid coolant. The secondary liquid coolant typically flows through a liquid circuit completely separate from the primary liquid coolant. The external receptacle volume may be formed by the body of the cold plate or defined by a retaining wall integral with it, further facilitating heat transfer. The volume is generally closed except that one side is typically open. The open side may be parallel (e.g., opposite) to the mounting surface of the cold plate (typically a plane), and such embodiments may be suitable for horizontal mounting. Alternatively, the open side may be perpendicular (e.g., adjacent) to the mounting surface of the cold plate, which may be suitable for vertical mounting.

[0014] Protrusions (pins and / or fins) may be formed within the volume of the external receptacle. This can facilitate heat transfer between the primary and secondary liquid coolants. In addition, or alternatively, protrusions (pins and / or fins) may be formed within the cold plate. These can facilitate heat transfer more generally, in particular, if the protrusions extend entirely (or at least substantially) between the inner surface of the cold plate adjacent to the electronic device being cooled and the inner surface of the cold plate opposite to it (generally adjacent to the volume of the external receptacle).

[0015] A cold plate generally forms part of a system that also includes a chassis housing electronic devices, and the cold plate is mounted on or adjacent to one of the electronic devices to cool one of the electronic devices and a primary liquid coolant. The primary liquid coolant flows (e.g., by pressure and / or convection) and is directed through a suitable nozzle into the volume of the cold plate's external receptacle. Thus, the primary liquid coolant can be cooled by contact with the cold plate, specifically its external receptacle. Multiple such cold plates may be provided, each cooling one or more different electronic devices, and they may be connected in series and / or parallel, as discussed below.

[0016] Advantageously, the primary liquid coolant flows out of the volume of the external receptacle (e.g., by overflow) and then at least partially immerses other electronic devices within the chassis. The height of the primary liquid coolant in the chassis outside the heatsink is lower than the height held within the volume of the external receptacle. This forms multiple heights of primary liquid coolant, reducing the amount of primary liquid coolant required without reducing the efficiency of heat transfer. In particular, the system may be configured so that all primary liquid coolant flows through the volume of the external receptacle of one or more cold plates.

[0017] The chassis is advantageous (for example, by using quick-release connectors) outside the chassis. It is provided with inlets and outlets for the secondary liquid coolant, both to and from the outside. Piping may then be provided for transferring the cold secondary liquid coolant from the inlet to the cold plate and the heated secondary liquid coolant from the cold plate to the outlet. An inlet manifold may be provided between the inlet and the piping, and / or an outlet manifold may be provided between the piping and the outlet. Manifolds may be useful for connecting multiple cold plates in parallel to the same inlet and outlet. In addition, or alternatively, the cold plates may be connected in series. If multiple cold plates are provided, one, some, or all of the cold plates may conform to the cold plate designs disclosed herein.

[0018] The primary liquid coolant may flow by convection and / or pressure. If a pump is used, a pump manifold may be provided to connect a single pump to multiple cold plates. In embodiments, multiple pumps may be used. For example, each pump may form part of its respective cold plate. This may take the form of, for example, a micropump.

[0019] This disclosure may be put into practice in several ways, and preferred embodiments are described herein by reference only with reference to the accompanying drawings. [Brief explanation of the drawing]

[0020] [Figure 1] This is a schematic isometric view of the interior of a server chassis according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a schematic plan view of the inside of the server chassis. [Figure 3] Figure 1 is a schematic isometric view of some of the components inside the server chassis shown. [Figure 4] Figure 1 schematically shows an isometric view of a cold plate according to one embodiment of the present disclosure for use in the server chassis shown. [Figure 5]Exploded view of the cold plate of FIG. 4. [Figure 6] Schematic cross-sectional view of a cold plate according to an embodiment of the present disclosure. [Figure 7] Schematic cross-sectional view of a cold plate according to a simplified or modified embodiment of the present disclosure is shown. [Figure 8] Schematic separated isometric view of a part of the components within a server chassis in yet another variant of what is shown in FIG. 1. [Figure 9] Schematic separated isometric view of a plurality of cold plates and a part of further components within a server chassis in yet another variant of what is shown in FIG. 1 is shown.

Mode for Carrying Out the Invention

[0021] Detailed Description of Preferred Embodiments The present disclosure generally provides hybrid cold plate and heat sink components for use in multi-stage (single-phase) liquid cooling systems, particularly for cooling computer server blades, although those skilled in the art will recognize the applicability of the technology to cooling other electronic components and devices. The primary liquid coolant circulates within the server chassis (typically by pumping, although convection may also be used in addition to or instead of that). The general height of the primary liquid coolant within the chassis is used to cool the cooler components within the chassis. The hotter components are cooled by a cold plate thermally coupled to the component (particularly, attached to the cold plate). The cold plate receives secondary liquid coolant from outside the chassis. The primary liquid coolant and the secondary liquid coolant are isolated from each other in that they are separate and different (particularly, the primary liquid coolant is typically non-conductive while the secondary liquid coolant is generally aqueous) and do not directly contact each other. However, the primary liquid coolant is pumped directly onto the cold plate and held against the heat conductor of the cold plate in the container-shaped (receptacle) portion of the cold plate. The primary with respect to the cold plate body This retention of the liquid coolant allows for heat transfer between the primary and secondary liquid coolants.

[0022] Thus, the cold plate of this disclosure may represent a hybrid of a cold plate (using a water-based coolant) and a heatsink of the type disclosed in International Publication 2019 / 048864 (using a dielectric coolant). Cold plate technology provides high-performance cooling and focuses on cooling the hottest components. However, the approach taken by this disclosure avoids the need for the cold plate to be directly attached to each component. The cold plate cools the hottest components (e.g., a processor or graphics processing unit, GPU), while the remaining components are cooled using a dielectric coolant.

[0023] In a generalized first embodiment, a cold plate may be considered. The cold plate is configured to use isolated (in other words, separate, isolated, or unmixed) primary and secondary liquid coolants. The cold plate comprises a heat conductor, which is configured to be mounted to an electronic device (e.g., by one or more of the following: molding and / or sizing of the heat conductor, and providing mounting points and / or holes) to define an internal volume (for receiving the secondary liquid coolant) and to transfer heat from the electronic device to the internal volume (through the heat conductor), and the cold plate further comprises a coolant inlet for receiving the secondary liquid coolant into the internal volume to receive the transferred heat, and a coolant outlet for the secondary liquid coolant to flow out of the internal volume. The heat conductor is further configured (e.g., molded or positioned) to define an external receptacle (i.e., a receptacle outside the cold plate body or housing, as opposed to the internal volume inside the body). The external receptacle has a certain volume and is configured to receive and hold the primary liquid coolant for heat transfer between the primary and secondary liquid coolants. In particular, the volume of the external receptacle is substantially closed on all sides except one side (e.g., except for a relatively small hole).

[0024] Such a configuration offers significant advantages compared to existing methods. A cold-plate heatsink hybrid device of such design provides an efficient primary (e.g., dielectric) liquid coolant loop in which heat is efficiently transferred from the flowing primary liquid coolant to a secondary (e.g., aqueous or essentially water-based) liquid coolant. As will be discussed further below, there are resulting benefits in terms of pressure, space, and power. Further optional and / or preferred features will be discussed below in a more generalized sense, but further details of specific embodiments are presented first.

[0025] Referring first to Figure 1, a schematic isometric view of the interior of a server chassis 1 according to an embodiment of the present disclosure is shown. In this figure, the aqueous (secondary) coolant loop is particularly shown. This includes an inlet quick-release connector 2; an inlet hose 3; an inlet manifold 4; an inlet piping hose 5; a cold plate heat sink hybrid device 6; an outlet piping hose 7; an outlet manifold 8; an outlet hose 10; and an outlet quick-release connector 11. Other features forming part of this embodiment are discussed below with reference to Figure 2.

[0026] The secondary coolant enters the liquid-tight chassis housing 1 through the inlet quick-release connector 2 at the rear of the chassis 1. The coolant then passes through the inlet hose 3 and, via the inlet manifold 4 (in this case there are two paths, but it will be understood that there could be more), is divided into two paths defined by each inlet piping hose 5, each directing the secondary liquid coolant to its respective cold plate heatsink hybrid device 6. The secondary liquid coolant passes through each cold plate heatsink hybrid device 6, cooling the electronic components to which the device 6 is mounted. These are relative. Although the electronic components are relatively hot, they are not visible in this diagram (due to the cold plate heat sink hybrid device 6). After passing through the cold plate heat sink hybrid device 6, the secondary liquid coolant (which is still in liquid form as it is a single-phase system) flows through the outlet piping hose 7 to the outlet manifold 8, and then through the outlet hose 10 and the outlet quick-release device 11.

[0027] Referring next to Figure 2, a schematic plan view of the interior of the server chassis 1 shown in Figure 1 is shown. The same reference numerals are used where the same features as in Figure 1 are shown. This shows the primary (dielectric) liquid coolant loop in more detail. In this regard, the embodiment further includes a base 12; a pump 13; a pump inlet nozzle 14; an outlet nozzle 16; a relatively low-temperature component 17; a primary coolant pipe 18; a pump outlet hose 19; and a pump outlet manifold 20. Further details regarding the cold plate heat sink hybrid device 6 are also more visible in that the device 6 includes a receptacle portion that defines the volume outside the cold plate heat sink hybrid device 15. The dielectric coolant typically sits in the base 12 of the liquid-tight chassis 1. The pump 13 picks up the hot liquid dielectric coolant through the pump inlet nozzle 14. The primary liquid coolant proceeds through the pump outlet hose 19 to the pump outlet manifold 20, through the coolant pipe 18, and enters the receptacle portion 15 of the cold plate heat sink hybrid device 6 via the outlet nozzle 16. The primary liquid coolant is then cooled by the secondary liquid coolant flowing through the cold plate portion of the cold plate heat sink hybrid device 6. The primary liquid coolant accumulates and overflows in the receptacle portion 15. The overflowed primary liquid coolant then collects with other primary liquid coolants and cools all other cryogenic components 17 before or when returning to the pump inlet nozzle 14.

[0028] Typically, the height of the primary liquid coolant within the base 12 is lower than the height of the primary liquid coolant held within the receptacle portion 15 of the cold plate heat sink hybrid device 6. In this way, neither the cryogenic component 17 nor the cold plate heat sink hybrid device is immersed in the primary liquid coolant. However, the cryogenic component 17 is at least partially immersed in the primary liquid coolant, and the primary liquid coolant receives at least some of the heat generated by the cryogenic component.

[0029] Referring to Figure 3, schematic isometric views of some of the components within the server chassis shown in Figures 1 and 2 are shown. This part relates to the primary liquid coolant loop (or circuit) as described above, but the flow from the receptacle portion 15 of the cold plate heat sink hybrid device 6 to the base 12 of the chassis 1 is not shown in this figure. The same reference numerals are used to label the same features as those shown in the previous drawings.

[0030] A key aspect of the cold plate heat sink hybrid device 6 is that the primary liquid coolant (and typically all primary liquid coolants) is cooled by a secondary liquid coolant loop, specifically by the primary liquid coolant being pumped onto the cold plate and held relative to the cold plate within a special receptacle section. The secondary liquid (aqueous) coolant flowing through the cold plate heat sink hybrid device 6 is colder than the heated primary (dielectric) liquid coolant. This will be further explained below.

[0031] Next, referring to Figure 4, an isometric view of the cold plate heat sink hybrid device 6, shown in more detail in the previous drawing, is schematically shown. Also refer to Figure 5, which shows an exploded view of the cold plate heat sink hybrid device 6 of Figure 4 and is used to illustrate the possible structure and operation of this device. The same reference numerals are used when the same features as those shown in the previous drawing are shown. The cold plate heat sink hybrid device 6 consists of a base 27; an upper housing 22; a cold plate internal volume 23; and This includes the receptacle portion 15 (described above). The base 27 and upper housing 22 define a closed cold plate internal volume 23 for receiving a secondary liquid coolant. The upper housing 22 also defines the receptacle portion 15. The base 27 is adapted for attachment to an electronic device or component, for example, by mounting holes 28 formed in the base 27. An upper pin 21 is provided on the receptacle portion 15, and a lower pin 26 is provided on the cold plate internal volume 23.

[0032] The interface between the internal volume 23 of the cold plate and the receptacle portion 15 defines a heat transfer zone between the primary and secondary liquid coolants. The relatively cool (water-based) secondary liquid coolant cools the heat transfer zone and pins 21 within the receptacle portion 15. This then cools the primary (dielectric) liquid coolant before it overflows into the server chassis 1. Since the pump 13 constantly circulates the hot primary liquid coolant through this circuit, all of the primary liquid coolant passes through the cold plate heat sink hybrid device 6, particularly its receptacle portion 15, and is therefore actively cooled by the secondary (water-based) liquid coolant side of the system. By pumping the primary liquid coolant through this loop so that all of it is cooled, no stagnant regions (where the primary liquid coolant remains hot) are created in the server chassis 1. Thus, the heat transfer performance of such an implementation is high.

[0033] Furthermore, cooling the entire primary liquid coolant in a cold-plate heatsink hybrid device 6, rather than using a plate heat exchanger (as described, for example, in International Publication 2019 / 048864), means that the overall pressure drop within the primary liquid coolant loop is significantly smaller. This has several advantages, namely, fewer pumps are required for this cooling loop, saving space; less pump power is required, saving energy; valuable space within the chassis 1 is not occupied by one or more plate heat exchangers; the area for cooling the primary liquid coolant is confined on the cold plate 6, which can be kept within a height of 1U, resulting in zero footprint on the primary liquid coolant within the chassis 1.

[0034] Returning to the generalized meaning discussed above, the side that is not substantially closed can be considered to be approximately parallel to the surface of the body that is configured to be mounted on an electronic device.

[0035] In embodiments, the cold plate may further include external projections formed within the volume of the external receptacle to facilitate heat transfer between the primary and secondary liquid coolants. For example, the heat conductor may form a retaining wall that at least partially defines the volume of the external receptacle. In this case, the external projections are advantageously substantially the same size as (and nearly parallel to) the height of the retaining wall.

[0036] Additionally or alternatively, the cold plate may further comprise internal projections formed within the internal volume of the heat conductor to facilitate heat transfer, particularly from the electronic device to the internal volume and / or between the primary and secondary liquid coolants. In a preferred embodiment, the internal projections substantially extend between (or over the entire distance between) the surface of the internal volume distal to the external receptacle and the surface of the internal volume adjacent to the external receptacle. This may provide improved heat transfer and increased structural integrity.

[0037] Optionally, the outer projection and / or inner projection may be equipped with pins and / or fins.

[0038] In another generalized embodiment, which may be combined with any other embodiments described herein, a system for cooling an electronic device may be considered, the electronic device and comprising a sealable module (e.g., liquid-tight) for housing a primary liquid coolant, the system is configured such that the primary liquid coolant flows (e.g., by convection and / or pressure) during operation, the system further comprising a cold plate mounted on at least one of the electronic devices (in particular to receive heat from at least one of the electronic devices) and having an external receptacle for receiving the primary liquid coolant (and configured to receive a secondary liquid coolant internally), and a nozzle configuration configured to direct the flowing primary liquid coolant into the volume of the external receptacle of the cold plate. The system is advantageously configured such that (all) of the primary liquid coolant is cooled by contact with the cold plate, specifically its external receptacle. Preferably, according to the present disclosure, the system is configured such that all of the primary liquid coolant flows through the volume of the external receptacle of at least one cold plate.

[0039] Advantageously, the primary liquid coolant flows from the nozzle configuration into the volume of the cold plate's external receptacle and out of the volume of the cold plate's external receptacle (e.g., by overflow) to at least partially immerse other electronic devices housed within the sealable module. These other electronic devices typically have operating temperatures lower than those of the electronic devices cooled by the cold plate. In particular, the height of the primary liquid coolant at least partially immersing the other electronic devices housed within the sealable module is lower than the height of the primary liquid coolant held within the volume of the cold plate's external receptacle.

[0040] The system may further include a module coolant inlet for receiving secondary liquid coolant from outside the sealable module, and an inlet piping configuration configured to supply secondary liquid coolant from the module coolant inlet to the coolant inlet of the cold plate. In addition, or alternatively, the system may further include a module coolant outlet for supplying secondary liquid coolant to outside the module, and an outlet piping configuration configured to supply secondary liquid coolant from the coolant outlet of the cold plate to the module coolant outlet.

[0041] In some embodiments, the system further includes an inlet manifold connected to the module coolant inlet and configured to direct secondary coolant from the module coolant inlet to the inlet piping configuration. Additionally or alternatively, the system may further include an outlet manifold connected to the module coolant outlet and configured to direct secondary coolant from the outlet piping configuration to the module coolant outlet.

[0042] The system preferably further comprises a pump configuration configured to deliver a primary liquid coolant to a nozzle configuration of a cold plate within a sealable module. The pump configuration may have one or more pumps, as will be discussed below. Convection may assist the flow of the primary liquid coolant, and in some less preferred embodiments, the flow of the primary liquid coolant may be entirely convective. In this case, piping and one or more nozzles are provided to direct the flow of the coolant accordingly.

[0043] Multiple cold plates may be used, each of which may be configured to cool one or more electronic devices within the module. For example, the cold plate described in general terms above may be considered the first cold plate. The system may then further include a second cold plate mounted on it to receive heat from at least one other electronic device among the electronic devices, the second cold plate having a coolant inlet and a coolant outlet. The second cold plate may conform to any of those described herein, or may be a different, for example, more conventional cold plate.

[0044] In some embodiments, the inlet piping configuration further includes a secondary liquid coolant in the inlet manifold. The system is configured to supply coolant from the first to the coolant inlet of the second cold plate. The outlet piping configuration may further supply the second liquid coolant from the coolant outlet of the second cold plate to the outlet manifold. In other words, the secondary liquid coolant loops of the first and second cold plates may be arranged in parallel.

[0045] Alternatively, the secondary liquid coolant loops of the first and second cold plates may be arranged in series. The outlet piping configuration is then further configured to supply secondary liquid coolant from the coolant outlet of the first cold plate to the coolant inlet of the second cold plate, and from the coolant outlet of the second cold plate to the module coolant outlet.

[0046] If a second cold plate is used, the system may further include a pump manifold configured to direct the primary liquid coolant from the pump to the nozzle configuration of the first cold plate and the nozzle configuration of the second cold plate. Additionally or alternatively, the pump configuration may include a plurality of pumps, for example, a first pump configured to direct the primary liquid coolant to the nozzle configuration of the first cold plate and a second pump configured to direct the primary liquid coolant to the nozzle configuration of the second cold plate.

[0047] In some embodiments, the system may further include a heat exchanger located outside the sealable module, configured to receive a secondary liquid coolant from the sealable module and to transfer heat from the secondary liquid coolant to, for example, a fluid (which may be liquid or gas). In some embodiments, the heat removal unit may be unitized for this purpose.

[0048] Here, we will discuss further details of a specific embodiment. Generalized explanations will also be given in the following respects.

[0049] Referring now to Figure 6, a schematic cross-sectional view of the cold plate heat sink hybrid device 6 as shown in the previous drawing is shown. The same features as shown previously are given the same reference numerals. In this figure, the cold plate heat sink hybrid device 6 is mounted on an electronic component 25 (integrated circuit, IC, etc.). The electronic component 25 is mounted on a substrate 24, which may be a printed circuit board (PCB) or even the base 12 of the chassis 1. Other low-temperature components 17 mounted on the substrate 24 are also shown. Both the upper pin 21 in the receptacle portion 15 and the lower pin 26 in the cold plate internal volume 23 are shown. The pin 26 in the cold plate internal volume 23 is full height, extends, contacts, and bridges the gap between the base 27 (which is in contact with the electronic component 25) and the heat transfer zone defined in the upper housing 22. In other words, the pin 26 connects the base 27 to the upper housing (lid) 22 of the cold plate heat sink hybrid device 6. This provides a significant benefit to heat transfer between the primary and secondary liquid coolants, improving cooling performance. The full-height pins 26 also improve the strength of the components and eliminate the ability of the coolant to take shortcuts around the pins 26.

[0050] Referring now to Figure 7, a schematic cross-sectional view of a simplified or modified cold plate heat sink hybrid device 6 is shown. This is essentially the same as that shown in Figure 6, except that the upper pin 21 and lower pin 26 are absent. The omission of these pins allows us to see further details. In particular, the height 30 of the primary liquid coolant within the chassis 1 is shown. In this example, the height 30 is sufficient to cover the electronic components 25 (which will be cooled by the cold plate 6 in any case) and partially cover the cryogenic components 17. Thus, the height 30 of the primary liquid coolant within the chassis 1 is generally low and is lower than the height of the primary liquid coolant within the receptacle portion 15 of the cold plate heat sink hybrid device 6 (which extends from the upper housing 22 to the height of the receptacle portion 15).

[0051] Similar to the heatsink described in International Publication 2019 / 048864, the cold plate heatsink hybrid device of this disclosure can be mounted either horizontally or vertically to accommodate high-temperature components on different format PCBs or motherboards. Referring to Figure 8, a schematic isometric view of some components within a server chassis in a further variation of the one shown in Figure 1, where the electronic components to be cooled and the cold plate heatsink hybrid device cooling them are mounted vertically. The same reference numerals label the same features as those shown in the other drawings. In this embodiment, a vertically mounted cold plate heatsink hybrid device 36 is shown together with a vertically oriented PCB 5 on which other low-temperature components 37 are provided above. This is substantially the same as the cold plate heatsink hybrid device 6 shown previously, but with a different configuration of its upper housing to define the receptacle portion to be slightly different. While the receptacle portion 15 of the previously described cold plate heat sink hybrid device 6 has an open side opposite the internal volume of the cold plate, in this modified cold plate heat sink hybrid device 36, the open side of the receptacle portion is adjacent to the internal volume of the cold plate, allowing the coolant to be retained within the receptacle portion when the cold plate heat sink hybrid device 36 is mounted such that the open side is distal to the base of the chassis. Furthermore, the outlet nozzle 16 is positioned to direct the primary liquid coolant into the volume of the receptacle portion distal to the open side. This allows the primary coolant to flow within the receptacle portion from the bottom until it overflows at the open side.

[0052] In the general terminology discussed above, if the volume of an external receptacle is substantially closed on all but one side, the substantially unclosed side may be considered perpendicular to the surface of the body to which it is to be mounted on an electronic device. In this case, if an external projection is provided and the thermal conductor forms a retaining wall that at least partially defines the volume of the external receptacle, the external projection may, advantageously, be substantially perpendicular to at least a portion of the retaining wall.

[0053] Referring to Figure 9, schematic isometric views of some of the multiple cold plates and further components within the server chassis in yet another modification are shown. Again, the same features are given the same reference numerals. In this modification, each cold plate heatsink hybrid unit 6 has its own individual micropump 28. The micropump 28 replaces the need for a single central pump 13, as shown in the previous drawings. This has several advantages, namely, a lower pressure drop; a lower coolant height; reduced cost; partial redundancy (failure of a single micropump 28 does not have to prevent the successful operation of the system); and the micropump 28 and cold plate heatsink hybrid unit 6 can be installed as a single subassembly. This modification may also be applied to a vertically mounted cold plate heatsink hybrid unit 36, as shown, for example, in Figure 8.

[0054] In the generalized sense discussed above, each pump in the pump configuration may form (or be integrated with) a portion of its respective cold plate. For example, the first pump may form a portion of the first cold plate, and the second pump may form a portion of the second cold plate. For this purpose, the pumps (or each pump) may be micropumps.

[0055] While specific embodiments have been described, those skilled in the art will understand that various modifications and changes are possible. For example, the structure and / or design of the cold plate heat sink hybrid device 6,36 may differ from those shown. Other applications are also possible. A flat surface is preferred, but for example, a stepped base (thermal interface) surface (having multiple parallel planes) may be used. Any combination of pins, fins or other protrusions may be used, where pins are shown to increase the cooling surface area and / or improve the structural integrity. While specific multi-part cold plate assemblies are described, it should be understood that cold plate heat sink hybrid devices may be realized using other multi-part assemblies or as devices constructed as a single unit. The main flow of primary liquid coolant from the receptacle portion of cold plate heat sink hybrid devices 6, 36 is described by overflow, but in addition, or alternatively, holes may be provided in the receptacle portion to allow the primary liquid coolant to flow out to the rest of the chassis internal volume. Multiple cold plates are shown in the drawings with their secondary liquid coolant loops in a favorable parallel configuration, but configurations in series or a combination of series and parallel are possible.

[0056] All features disclosed herein may be combined in any combination, except for any combination in which at least some of such features and / or steps are mutually exclusive. In particular, preferred features of the present invention are applicable to all aspects of the invention and can be used in any combination. Similarly, features described in non-essential combinations may be used separately (rather than in combination).

Claims

1. A cold plate configured to use separated primary and secondary liquid coolants, A heat conductor configured to define an internal volume and transfer heat from an object to be cooled to the internal volume, A coolant inlet for receiving the secondary liquid coolant into the internal volume so as to receive the transferred heat, Equipped with a coolant outlet, A cold plate wherein the heat conductor is further configured to define an external receptacle having a volume configured to receive and hold the primary liquid coolant for heat transfer between the primary liquid coolant and the secondary liquid coolant.

2. The cold plate according to claim 1, wherein the volume of the external receptacle is substantially closed on all sides except one side.

3. The cold plate according to claim 2, wherein the substantially open side is substantially parallel or perpendicular to the surface of the heat conductor configured for mounting on the object to be cooled.

4. The cold plate according to any one of claims 1 to 3, further comprising an external projection formed within the volume of the external receptacle to facilitate heat transfer between the primary liquid coolant and the secondary liquid coolant.

5. The cold plate according to claim 4, wherein the heat conductor forms a retaining wall that at least partially defines the volume of the external receptacle, and the external projection is substantially the same size as the height of the retaining wall.

6. The cold plate according to any one of claims 1 to 3, further comprising internal protrusions formed within the internal volume of the heat conductor to facilitate heat transfer from the object to be cooled to the internal volume and / or heat transfer between the primary liquid coolant and the secondary liquid coolant.

7. The cold plate according to claim 6, wherein the internal projection substantially extends between the surface of the internal volume distal to the external receptacle and the surface of the internal volume adjacent to the external receptacle.

8. A system for cooling an object to be cooled, The system comprises a sealable module that houses the object to be cooled and a primary liquid coolant, the system is configured such that the primary liquid coolant flows during operation, and the system further comprises A cold plate according to any one of claims 1 to 3, which is attached to at least one of the objects to be cooled, A system comprising a nozzle configuration configured to direct the flowing primary liquid coolant into the volume of the external receptacle of the cold plate.

9. The system according to claim 8, wherein the primary liquid coolant is further configured to flow from the nozzle configuration into the volume of the external receptacle of the cold plate, and out of the volume of the external receptacle of the cold plate, at least partially immersing other objects to be cooled housed in the sealable module.

10. The system according to claim 9, wherein the height of the primary liquid coolant that at least partially immerses other objects to be cooled housed within the sealable module is lower than the height of the primary liquid coolant held within the volume of the external receptacle of the cold plate.

11. A module coolant inlet for receiving the secondary liquid coolant from the outside of the sealable module, A module coolant outlet for supplying the secondary liquid coolant to the outside of the sealable module, An inlet piping configuration configured to supply the secondary liquid coolant from the module coolant inlet to the coolant inlet of the cold plate, The system according to claim 8, further comprising an outlet piping configuration configured to supply the secondary liquid coolant from the coolant outlet of the cold plate to the module coolant outlet.

12. An inlet manifold connected to the module coolant inlet and configured to direct the secondary liquid coolant from the module coolant inlet to the inlet piping configuration, The system according to claim 11, further comprising an outlet manifold connected to the module coolant outlet and configured to direct the secondary liquid coolant from the outlet piping configuration to the module coolant outlet.

13. The cold plate is a first cold plate, and the system further comprises: The system comprises a second cold plate mounted on at least one of the objects to be cooled, the second cold plate having a coolant inlet and a coolant outlet, The system according to claim 12, wherein the inlet piping configuration is further configured to supply the secondary liquid coolant from the inlet manifold to the coolant inlet of the second cold plate, and the outlet piping configuration is further configured to supply the secondary liquid coolant from the coolant outlet of the second cold plate to the outlet manifold.

14. The cold plate is a first cold plate, and the system further comprises: The system comprises a second cold plate mounted on at least one of the objects to be cooled, the second cold plate having a coolant inlet and a coolant outlet, The system according to claim 11, wherein the outlet piping configuration is further configured to supply the secondary liquid coolant from the coolant outlet of the first cold plate to the coolant inlet of the second cold plate, and from the coolant outlet of the second cold plate to the module coolant outlet.

15. The system according to claim 13, wherein the second cold plate is according to any one of claims 1 to 3.

16. The system according to claim 8, further comprising a pump configuration configured to flow the primary liquid coolant into the nozzle configuration of the cold plate within the sealable module.

17. The cold plate is a first cold plate, and the system further comprises: A second cold plate according to any one of claims 1 to 3, The system according to claim 16, further comprising a pump manifold configured to direct the primary liquid coolant from the pump configuration to the nozzle configuration of the first cold plate and the nozzle configuration of the second cold plate.

18. The cold plate is a first cold plate, and the system further comprises: Further comprising a second cold plate according to any one of claims 1 to 3, The system according to claim 16, wherein the pump configuration includes a first pump configured to direct the primary liquid coolant towards the nozzle configuration of the first cold plate, and a second pump configured to direct the primary liquid coolant towards the nozzle configuration of the second cold plate.

19. The system according to claim 18, wherein the first pump forms part of the first cold plate, and the second pump forms part of the second cold plate.

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