Multi-channel based cooling device for chips

Abstract

Disclosed is a multi-channel cold plate for cooling a chip, wherein a first set of cooling channels acts as a primary cooling channel and a second set of cooling channels acts as a secondary and / or backup cooling channel. The two sets of cooling channels are fluidically isolated from each other such that cooling fluid from one set of channels cannot flow or mix with the cooling fluid of the other cooling channel. The secondary cooling channels can be operated when the heat dissipation requirements increase or when the primary cooling channels cannot properly manage the thermal conditions of the chip.

Description

Technical Field

[0001] Embodiments of the present invention generally relate to enhanced and reliable cooling of advanced microchips, such as those used in servers within data centers. Background Technology

[0002] Cooling is a critical factor in computer system and data center design. The number of high-performance electronic components, such as high-performance processors, packaged within servers is steadily increasing, thereby increasing the heat generated and dissipated during normal server operation. The proper functioning of these processors is highly dependent on the reliable removal of the heat they generate. Therefore, proper cooling of the processors can provide high overall system reliability.

[0003] Cooling electronic devices is critical for computing hardware and other electronic devices such as CPU servers, GPU servers, storage servers, networking devices, edge and mobile systems, and in-vehicle computing boxes. All these devices and computers are used in mission-critical environments and are fundamental to the company's day-to-day operations. Improvements in the design of hardware components and electronic device packages are needed to continuously support performance requirements. Cooling these electronic devices is becoming increasingly challenging, requiring the provision of a properly designed and reliable thermal environment to ensure their proper functioning.

[0004] Many advanced chips, especially high-power-density chips, require liquid cooling. These chips are very expensive, so every effort must be made to ensure proper heat dissipation from them. Moreover, the liquid cooling equipment must be highly reliable, as any irregular heat dissipation can lead to chip loss, resulting in lost processing time during replacement operations, and may even affect the service level agreement processed by the lost chip.

[0005] While liquid cooling solutions must provide the required thermal performance and reliability, the cost of such systems must be kept acceptable given that data centers may have thousands of chips requiring liquid cooling. The cost of a liquid cooling system may include the cost of introducing redundancy to improve reliability. Furthermore, since different chips have different cooling requirements, it is desirable to provide cooling designs that can adapt to these diverse requirements. Summary of the Invention

[0006] To address the technical problems existing in the prior art, this invention proposes a cold plate for cooling microchips and a cooling system for cooling microchips.

[0007] The present invention proposes a cold plate for cooling a microchip, comprising a heat-conducting plate assembly having a first set of cooling channels and a second set of cooling channels, and further having an inlet port and a return port, wherein the inlet port is used to deliver cooling fluid to the first set of cooling channels, the return port is used to remove vapor from the first set of cooling channels, and wherein the second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent the cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels.

[0008] In some embodiments, the second set of cooling channels includes multiple isolated, independently sealed chambers, each forming a two-phase evaporation and condensation chamber.

[0009] In some implementations, each of the isolated, individually sealed cavities includes a wicking block.

[0010] In some embodiments, the second set of cooling channels includes multiple secondary cooling channels connected to a cooling fluid inlet and a return outlet.

[0011] In some embodiments, each of the cooling channels in the first group includes fins, and each of the cooling channels in the second group does not have fins.

[0012] In some embodiments, the cooling channels in the first set of cooling channels are interleaved with the cooling channels in the second set of fluid channels.

[0013] In some embodiments, the cross-section of the cooling channel in the first group of cooling channels has a different size than the corresponding cross-section of the cooling channel in the second group of cooling channels.

[0014] In some embodiments, the coverage area of ​​the cooling channel in the first group of cooling channels has a different size than the corresponding coverage area of ​​the cooling channel in the second group of cooling channels.

[0015] In some embodiments, the heat-conducting plate assembly includes: a contact plate; an upper plate; a core sandwiched between the contact plate and the upper plate, wherein a first set of cooling channels and a second set of cooling channels are formed within the core; and a main cooling fluid supply manifold formed in one of the contact plate or the upper plate.

[0016] In some embodiments, the core includes alternating ridges and grooves that form corrugations.

[0017] In some embodiments, the corrugations are skewed, such that the cooling channels in the first set of cooling channels have different dimensions than the cooling channels in the second set of cooling channels.

[0018] In some embodiments, the cold plate further includes a secondary cooling fluid supply manifold formed in one of the contact plate or the upper plate; and wherein the primary cooling fluid supply manifold is fluidly connected to the first set of cooling channels, and the secondary cooling fluid supply manifold is fluidly connected to the second set of cooling channels.

[0019] In some embodiments, the first set of cooling channels is configured for a thermal cycle selected from pumped single-phase cooling, pumped two-phase cooling, and pumpless single-loop thermosiphon cooling, and the second set of cooling channels is configured for a thermal cycle selected from pumped single-phase cooling, pumped two-phase cooling, and pumpless single-loop thermosiphon cooling, wherein the thermal cycle of the second set of cooling channels is different from the thermal cycle of the first set of cooling channels.

[0020] In some embodiments, the second set of cooling channels includes a secondary fluid that is different from the cooling fluid delivered to the first set of cooling channels.

[0021] The present invention also proposes a cooling system for cooling microchips, comprising:

[0022] A cold plate assembly, wherein the cold plate assembly incorporates a first set of cooling channels and a second set of cooling channels, wherein the second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent the cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels;

[0023] Main condenser;

[0024] A main supply line, which is fluidly connected between the main condenser and the first set of cooling channels;

[0025] A main return line is fluidly connected between the main condenser and the first set of cooling channels.

[0026] In some embodiments, the cooling system further includes:

[0027] Secondary condenser;

[0028] A secondary supply line, fluidly connected between the secondary condenser and the first set of cooling channels; a pump connected to the secondary supply line; and

[0029] The secondary return line is fluidly connected between the secondary condenser and the first set of cooling channels.

[0030] In some embodiments, the second set of cooling channels includes multiple isolated, independently sealed chambers, each forming a two-phase evaporation and condensation chamber.

[0031] In some embodiments, the cold plate assembly includes: a contact plate; an upper plate; and a core sandwiched between the contact plate and the upper plate; wherein the first set of cooling channels and the second set of cooling channels are formed within the core.

[0032] In some embodiments, the cooling system further includes: at least one inlet manifold formed in one of the contact plate or the upper plate; and at least one return manifold formed in one of the contact plate or the upper plate.

[0033] In some embodiments, the cold plate assembly further includes at least one heat radiator that is in physical contact with the first set of cooling channels and the second set of cooling channels. Attached Figure Description

[0034] In the accompanying drawings, embodiments of the invention are shown by way of example rather than limitation, and the same reference numerals refer to similar elements.

[0035] Figure 1 This is a block diagram illustrating an example of a data center facility according to one implementation.

[0036] Figure 2 This is a block diagram illustrating an example of an electronic rack according to one embodiment.

[0037] Figure 3 This is a block diagram illustrating an example of a cold plate construction according to one embodiment.

[0038] Figure 4 This is a conceptual schematic diagram showing a cross-section of a cold plate according to an embodiment.

[0039] Figure 5 This is a general schematic diagram of a cold plate with a corrugated structure according to an embodiment.

[0040] Figure 6 A cold plate according to an embodiment is shown, wherein the secondary cooling channel is a separate evaporation chamber.

[0041] Figure 7 This is a top view of a cold plate with a heat radiator according to an embodiment.

[0042] Figure 8 The fluid flow and distribution in a cold plate according to the disclosed embodiment are shown.

[0043] Figure 9 An overall overview of a cooling system employing a cold plate according to an embodiment is shown.

[0044] Figure 10This is a general schematic diagram showing the operation of the cooling system according to an embodiment. Detailed Implementation

[0045] Various embodiments and aspects of the invention will be described with reference to the details discussed below, and the accompanying drawings will illustrate various embodiments. The following description and drawings are illustrative of the invention and should not be construed as limiting the invention. Numerous specific details are described to provide a thorough understanding of various embodiments of the invention. However, in some cases, well-known or conventional details are not described in order to provide a concise discussion of embodiments of the invention.

[0046] The reference to "one embodiment" or "an embodiment" in the specification means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the invention. The phrase "in one embodiment" appearing in different places in the specification does not necessarily refer to the same embodiment.

[0047] The disclosed embodiments provide enhanced cooling systems for electronic devices, which may include single-chip modules (SCMs), system-on-a-chip (SoCs), multi-chip modules (MCMs), system-in-package (SIPs), etc. For the sake of brevity, these are referred to herein as microchips or simply chips, but any such reference should be understood to include any of these and similar variations. It will be understood that such devices may even have different cooling requirements in different areas of the package itself. That is, different areas of the package may require different heat dissipation rates.

[0048] A cooling solution is disclosed that provides improved reliability and heat dissipation capabilities. Redundancy can be used to increase the heat dissipation rate as needed or to provide backup cooling in the event of a cooling system failure. The disclosed implementation also allows for the customization of different heat dissipation rates in different areas of the package. The following disclosure begins by providing background information on an example application of the disclosed implementation, and then proceeds to disclose specific implementations. While this example relates to operations within a data center, the disclosed implementation is not limited to data centers.

[0049] Figure 1 This is a block diagram illustrating an example of a data center or data center unit according to one implementation method. In this example, Figure 1 A top view of at least a portion of the data center is shown. (Reference) Figure 1According to one embodiment, a data center system 100 includes one or more rows of electronic racks of information technology (IT) components, equipment, or instruments 101-102 (e.g., computer servers or computing nodes) that provide data services to various clients via a network (e.g., the Internet). In this embodiment, each row includes an array of electronic racks such as electronic racks 110A-110N. However, more or fewer rows of electronic racks can be implemented. Typically, rows 101-102 are aligned in parallel, with their front ends facing each other and their rear ends facing each other, forming an aisle 103 between them to allow administrators to walk through. However, other configurations or arrangements can also be applied. For example, two rows of electronic racks can be back-to-back facing each other without forming an aisle between them, while their front ends face each other. The rear ends of the electronic racks can be connected to a room coolant manifold.

[0050] In one implementation, each electronic rack (e.g., electronic racks 110A-110N) includes a housing to accommodate a plurality of stacked IT components operating therein. The electronic rack may include a coolant manifold, a plurality of server slots (e.g., standard shelves or chassis configured with the same or similar form factor), and a plurality of server enclosures (also referred to as server blades or server shelves) capable of being inserted into and removed from the server slots. Each server enclosure represents a compute node having one or more processors, memory, and / or persistent storage devices (e.g., hard drives), wherein the compute node may include one or more servers operating therein. At least one processor is attached to a liquid cold plate (also referred to as a cold plate assembly) to receive coolant. Additionally, one or more optional cooling fans are associated with the server enclosure to provide air cooling to the compute nodes contained therein. Note that cooling system 120 may be coupled to multiple data center systems, such as data center system 100.

[0051] In one embodiment, the cooling system 120 includes an external liquid loop connected to a cooling tower or dry cooler outside the building / house container. The cooling system 120 may include, but is not limited to, evaporative cooling, free air cooling, large heat rejection, and waste heat recovery designs. The cooling system 120 may include or be coupled to a coolant source that provides coolant.

[0052] In one embodiment, each server chassis is modularly coupled to a coolant manifold, allowing server chassis to be removed from the electronics rack without affecting the operation of the remaining server chassis and coolant manifold within the rack. In another embodiment, each server chassis is coupled to a coolant manifold via a quick-release coupling assembly having a server liquid inlet connector and a server liquid outlet connector, which are coupled to flexible hoses to distribute coolant to the processors. The server liquid inlet connector receives coolant from a coolant manifold mounted at the rear end of the electronics rack via a rack liquid inlet connector. The server liquid outlet connector discharges warmer or hotter liquid, carrying heat exchanged from the processors, into the coolant manifold and then back to the coolant distribution unit (CDU) within the electronics rack via the rack liquid outlet connector.

[0053] In one embodiment, a coolant manifold disposed at the rear end of each electronic rack is connected to a liquid supply line 132 (also referred to as a room supply manifold) to receive coolant from the cooling system 120. The coolant is distributed via a liquid distribution loop attached to a cold plate assembly on which the processor is mounted to remove heat from the processor; the cold plate is constructed similarly to a radiator, with the liquid distribution pipe attached or embedded therein. The resulting warmer or hotter liquid, carrying the heat exchanged from the processor, is then delivered back to the cooling system 120 via a liquid return line 131 (also referred to as a room return manifold).

[0054] Liquid supply / return lines 131-132, referred to as data center or room liquid supply / return lines (e.g., global liquid supply / return lines), supply coolant to all electronic racks in rows 101-102. Liquid supply line 132 and liquid return line 131 are coupled to heat exchangers located within each electronic rack's CDU, forming a primary loop. The secondary loops of the heat exchangers are coupled to each server chassis within the electronic rack to deliver coolant to the processor's cold plate.

[0055] In one embodiment, the data center system 100 also includes an optional airflow delivery system 135 to generate airflow that passes through the air space of the server chassis of the electronic racks to exchange heat generated by the computing nodes (e.g., servers) due to their operation, and to exhaust the heat-exchanged airflow to the external environment or a cooling system (e.g., an air-to-liquid heat exchanger) to reduce the temperature of the airflow. For example, the air supply system 135 generates a cool / cold airflow to circulate from aisle 103 through electronic racks 110A-110N to remove the exchanged heat.

[0056] Cool air enters the electronic rack through the front end, while warm / hot air exits from the rear end. The warm / hot air, with exchanged heat, is exhausted from the room / building or cooled using a separate cooling system such as an air-liquid heat exchanger. Thus, the cooling system is a hybrid liquid-air cooling system, in which a portion of the heat generated by the processor is removed by coolant via corresponding cold plates, while the remaining heat generated by the processor (or other electronic equipment or processing unit) is removed by airflow cooling. Furthermore, liquid cooling can be a multiphase system in which the fluid flows in either a liquid or gas phase.

[0057] Figure 2 This is a block diagram illustrating an electronic rack according to one embodiment. The electronic rack 200 can be represented as follows: Figure 1 Any of the electronic racks shown, such as electronic racks 110A-110N. (Reference) Figure 2 According to one embodiment, the electronic rack 200 includes, but is not limited to, a CDU 201, a rack management unit (RMU) 202, and one or more server chassis 203A-203E (collectively referred to as server chassis 203). The server chassis 203 can be inserted into a server slot array (e.g., a standard shelf) from either the front end 204 or the rear end 205 of the electronic rack 200. Note that although five server chassis 203A-203E are shown here, more or fewer server chassis may be maintained within the electronic rack 200. It should also be noted that the specific locations of the CDU 201, RMU 202, and / or server chassis 203 are shown for illustrative purposes only; other arrangements or configurations of the CDU 201, RMU 202, and / or server chassis 203 may also be implemented. In one embodiment, the electronic rack 200 may be open to the environment or partially contained within a rack container, provided that cooling fans can generate airflow from the front to the rear end.

[0058] Additionally, for at least some of the server chassis 203, optional fan modules (not shown) are associated with the server chassis. Each fan module includes one or more cooling fans. The fan modules may be mounted on the rear end of the server chassis 203 or on the electronic rack to generate airflow that flows from the front end 204, travels through the air space of the server chassis 203, and is present at the rear end 205 of the electronic rack 200.

[0059] In one embodiment, CDU 201 primarily includes a heat exchanger 211, a liquid pump 212, and a pump controller (not shown), as well as other components such as a reservoir, power supply, monitoring sensors, etc. The heat exchanger 211 can be a liquid-liquid or multiphase heat exchanger. The heat exchanger 211 includes a first loop having an inlet port and an outlet port, the inlet and outlet ports having a first pair of liquid connectors connected to external liquid supply / return lines 131-132 to form a main loop. The connectors connected to the external liquid supply / return lines 131-132 can be arranged or mounted on the rear end 205 of the electronics rack 200. The liquid supply / return lines 131-132 (also referred to as room liquid supply / return lines) can be connected to the cooling system 120 as described above. As will be shown below in a specific embodiment of the cold plate, the arrangement of the liquid supply / return lines 131-132 can be doubled to provide two independent cooling loops. One circuit can operate continuously, while the second circuit can be used when additional cooling capacity is needed or as a backup.

[0060] Additionally, heat exchanger 211 includes a second loop with two ports having a second pair of liquid connectors that connect to liquid manifold 225 (also referred to as a rack manifold) to form a secondary loop. This secondary loop may include a supply manifold (also referred to as a rack liquid supply line or rack supply manifold) supplying coolant to server chassis 203 and a return manifold (also referred to as a rack liquid return line or rack return manifold) returning warmer liquid to CDU 201. Note that CDU 201 can be any kind of commercially available or custom CDU. Therefore, details of CDU 201 will not be described herein.

[0061] Each server chassis 203 may include one or more IT components (e.g., a central processing unit or CPU, a general-purpose / graphics processing unit (GPU), memory, and / or storage devices). Each IT component may perform data processing tasks, and the IT component may include software installed on storage devices, loaded into memory, and executed by one or more processors to perform data processing tasks. Server chassis 203 may include a host server (referred to as a master node) connected to one or more compute servers (also called compute nodes, such as CPU servers and GPU servers). The host server (having one or more CPUs) is typically connected to a client interface via a network (e.g., the Internet) to receive requests for specific services, such as storage services (e.g., cloud-based storage services such as backup and / or recovery), or applications to perform certain operations (e.g., image processing, deep data learning algorithms, or modeling, etc., as part of a Software as a Service or SaaS platform). In response to the request, the host server assigns the task to one or more compute nodes or compute servers (having one or more GPUs) managed by the host server. The compute servers perform the actual tasks and may generate heat during operation.

[0062] The electronics rack 200 also includes an optional RMU 202 configured to provide and manage power supplied to the server 203 and CDU 201. The RMU 202 can be coupled to a power supply unit (not shown) to manage the power consumption of the power supply unit. The power supply unit may include the necessary circuitry (e.g., AC-to-DC or DC-to-DC power converters, batteries, transformers, or regulators) to power the remaining components of the electronics rack 200.

[0063] In one implementation, RMU 202 includes an optimization module 221 and a rack management controller (RMC) 222. RMC 222 may include a monitor that monitors the operational status of various components within the electronic rack 200, such as compute nodes 203, CDU 201, and fan modules. Specifically, the monitor receives operational data from various sensors representing the operating environment of the electronic rack 200. For example, the monitor may receive operational data representing the temperature of the processor, coolant, and airflow, which may be captured and collected via various temperature sensors. The monitor may also receive data representing the fan power and pump power generated by the fan modules and liquid pump 212, which may be proportional to their respective speeds. This operational data is referred to as real-time operational data. Note that the monitor may be implemented as a separate module within RMU 202.

[0064] Based on the operating data, optimization module 221 performs optimization using a predetermined optimization function or optimization model to derive a set of optimal fan speeds for the fan module and optimal pump speeds for the liquid pump 212, minimizing the total power consumption of the liquid pump 212 and the fan module, while ensuring that the operating data associated with the cooling fans of the liquid pump 212 and the fan module are within their respective design specifications. Once the optimal pump speed and optimal fan speed are determined, RMC 222 constructs the cooling fans for the liquid pump 212 and the fan module based on the optimal pump speed and fan speed.

[0065] As an example, based on an optimal pump speed, RMC 222 communicates with the pump controller of CDU 201 to control the speed of liquid pump 212, which in turn controls the flow rate of coolant supplied to liquid manifold 225 to be distributed to at least some of the server chassis 203. Similarly, based on an optimal fan speed, RMC 222 communicates with each fan module to control the speed of each cooling fan in the fan module, which in turn controls the airflow rate of the fan module. Note that each fan module can be individually controlled with its specific optimal fan speed, and different fan modules and / or different cooling fans within the same fan module can have different optimal fan speeds.

[0066] Note that, as Figure 2 The rack configuration shown is for illustrative purposes only; other configurations or arrangements are also applicable. For example, CDU 201 may be an optional unit. The cold plate of server chassis 203 may be connected to a rack manifold that can be directly connected to room manifolds 131-132 without using a CDU. Although not shown, a power supply unit may be arranged within the electronics rack 200. The power supply unit may be implemented as a standard chassis identical or similar to the server chassis, wherein the power supply chassis can be inserted into any standard shelf, replacing any server chassis 203. Additionally, the power supply chassis may include a backup battery unit (BBU) that provides battery power to server chassis 203 when the main power supply is unavailable. The BBU may include one or more battery packs, and each battery pack includes one or more battery cells, as well as the necessary charging and discharging circuitry for charging and discharging the battery cells.

[0067] Figure 3 This is a block diagram illustrating a chip cold plate construction according to one embodiment. The chip / cold plate assembly 300 can be represented as follows: Figure 2 Any processor / cold plate configuration of the server chassis 203 shown. Reference Figure 3Chip 301 is inserted into a socket mounted on a printed circuit board (PCB) or motherboard 302, which is connected to other electrical components or circuitry of a data processing system or server. Chip 301 also includes a cold plate 303 attached to it, which is connected to a rack manifold, for example, via a blind-fit connector, to a liquid supply line 132 and / or a liquid return line 131. A portion of the heat generated by chip 301 is removed by the cold plate 303. The remaining heat enters the air space below or above and can be removed by airflow generated by a cooling fan 304. Note that although a single arrow is shown for both the liquid supply and return, some embodiments disclosed below may require two separate liquid supply lines and two separate liquid return lines.

[0068] Figure 4 This is a conceptual representation of a multi-channel cold plate 403 shown in cross-section according to an embodiment, which is placed on top of a chip 450. The body of the cold plate 403 may be made of a thermally conductive material such as a metal (e.g., copper or aluminum) or silicon. The cold plate 403 may be attached to or pressed against the chip 450 by various packaging devices, but the attached packaging devices are unrelated to the disclosed embodiment.

[0069] Multiple channels are fabricated within a single cold plate, with different channels functioning according to different thermal designs. The channels can be distributed along the entire coverage area of ​​the cold plate, which can cover the entire area of ​​the chip. In the disclosed embodiments, the multiple channels can be customized to operate two different phase change coolants or two different cooling modes, thereby constructing primary and secondary cooling channels for operation according to different thermal cycles. The two coolants can be independently distributed in two different cooling cycle systems, for example, one pumpless and one actively driven by a pump. The two cooling systems can be selected from various thermal cycles, such as pumped single-phase or two-phase cooling, pumpless single-loop thermosiphon systems, two-phase evaporative dielectric coolants, etc., and the coolant can include water or other types of phase change coolants. In one embodiment, the design includes a 3D vapor chamber and a phase change channel (thermosiphon) coexisting in a single cooling device. The 3D vapor chamber can function differently to perform heat dissipation from the recirculating cooling channel at different rates or with different capacities. In this arrangement, the 3D vapor chamber is an independent, autonomous cooling chamber, while the phase change channel is actively cooled by a cooling system that removes vapor from the channel and delivers cooled liquid into it.

[0070] By employing two distinct cooling channel cycles, the cold plate can operate in different modes. For example, one cooling cycle can operate as the primary cooling cycle and run continuously, while the second cooling cycle can act as a backup cycle when the primary cooling fails. In another example, the primary cooling can operate continuously, while the second cooling operates as an enhancer whenever the chip experiences high processing demands and thus generates more heat. In yet another example, the size and number of channels for each coolant type can be distributed across the plate area according to the chip design, allowing areas with enhanced processing to receive increased cooling rates, while areas with low heat dissipation receive less cooling. In yet another example, the cross-sections and / or coverage areas of the two channels are different; for example, the channels of the primary cooling cycle are larger than the channels of the backup or enhancer channel.

[0071] Back Figure 4 In the example shown, the cold plate 403 has two inlet ports 410 and 420. The plate also has two outlet ports, but these are not visible in this particular view. In this example, the main port 410 is the port of the main cooling system and supplies cooling fluid to the main channel 412 via the main manifold 414. The main channel 412 may include microfins to enhance heat transfer, and the main cooling system may be a pump-free two-phase cooling system (e.g., a two-phase thermosiphon system). The secondary port 420 delivers cooling fluid to the secondary channel 422 via the secondary manifold 424. As shown, the secondary channel 422 may be an open channel without microfins, or it may include fins similar to those in the main channel 412, and the secondary cooling system may be a pumped two-phase cooling system. Moreover, as Figure 4 As shown, the secondary channel 422 is smaller than the main channel 412, i.e., it occupies less area. The main channel 412 can operate continuously as the main cooling system for the chip. The secondary channel 422 can operate as an enhancer or backup cooling system, which operates only when additional cooling is required or when the main cooling system fails.

[0072] Therefore, a cold plate is typically provided, including a heat-conducting plate assembly that combines a first set of cooling channels and a second set of cooling channels, and further having an inlet port for delivering cooling fluid to the first set of cooling channels and a return port for removing vapor from the first set of cooling channels, wherein the second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels. The second set of cooling channels may also be coupled to a cooling fluid inlet and a return outlet. Each cooling channel in the first set of cooling channels may include fins, while each cooling channel in the second set of cooling channels may or may not have fins. The cooling channels in the first set of cooling channels may be staggered with the cooling channels in the second set of cooling channels.

[0073] Figure 5An example of an implementation is shown, which is a corrugated structure similar to corrugated cardboard. The cold plate 503 is composed of a contact plate 534 that physically contacts the chip 550. A core unit 530 is sandwiched between the contact plate 534 and the upper plate 532. The core unit 530 is shaped with alternating ridges and grooves, thus forming corrugations. One side of the corrugations forms channels for the primary cooling system, such as channel 512, while the other side forms channels for the secondary cooling system, such as channel 522. Therefore, the primary and secondary channels are staggered. In the example shown, the corrugations are uniform, such that all channels have the same dimensions. In another example, the corrugations may be skewed, such that the channels on the primary cooling system have different dimensions than the channels on the secondary cooling system.

[0074] exist Figure 5 In the example shown, the corrugations facing the opening of contact plate 534 are designated #1, and circulate the main cooling fluid via manifold 514 leading to inlet 410. The outlet is not visible in this view. Conversely, the corrugations facing the opening of upper plate 532 are designated #2, and circulate the secondary cooling fluid via manifold 524 leading to inlet 420. The secondary outlet is not visible in this view. Figure 5 As indicated by the label, in one example, fins 536 are added within the corrugation labeled #1, but not within the corrugation labeled #2. Conversely, in other embodiments, fins 536 may also be included within the corrugation labeled #2.

[0075] The disclosed embodiments provide a heat-conducting plate assembly including: a contact plate; an upper plate; a core sandwiched between the contact plate and the upper plate, wherein a first set of cooling channels and a second set of cooling channels are formed within the core; and a main cooling fluid supply manifold formed in one of the contact plate or the upper plate, wherein the second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels. The core may include alternating ridges and grooves forming corrugations. Furthermore, the corrugations may be deflected such that the cooling channels in the first set of cooling channels have different dimensions than the cooling channels in the second set of cooling channels.

[0076] Figure 6 This is a cross-section of another embodiment of a multi-channel cold plate incorporating two different cooling methods. This particular illustration utilizes a corrugated structure, but the features can be incorporated into any structure disclosed herein or other suitable structures. In this embodiment, the main cooling channel, identified as #1, is a pure evaporation channel designed for thermosiphoning, while the secondary cooling channel, identified as #2, is designed for two-phase cooling, wherein both evaporation and condensation occur within each channel.

[0077] In the cold plate 603, the contact plate 634 may be incorporated with an inlet manifold 614 that delivers cooling fluid from the inlet port 610 to the main channel 612. The contact plate 634 physically contacts the chip 650 to remove heat from the chip. The cooling channel 612 operates as an evaporation channel and collects vapor to the outlet port 618 via an outlet manifold 616 that may be incorporated into the upper plate 632. As indicated by the label, the main channel may be incorporated with cooling fins 636.

[0078] The core unit 630 is formed as a corrugated structure, with a main cooling channel on one side and a secondary cooling channel on the opposite side. In this example, the corrugations are asymmetrical or skewed, causing the dimensions of the main cooling channel to differ from those of the secondary channels. In this particular figure, the secondary channel is shown to be larger than the main channel, but the channels can have the same dimensions, or the main channel can be larger than the secondary channel. Figure 6 In this embodiment, the secondary cooling channels are designed as fully two-phase channels, allowing evaporation and condensation to occur within the channels themselves. Therefore, there are no fluid supply or return ports for the secondary channels, which can be independent sealed cavities. As indicated by the dashed lines, the bottom of each secondary channel may include a wicking block 639, which holds the coolant. When the coolant heats up, it evaporates and rises toward the top of the channel, where it contacts the upper plate 632 and condenses. During condensation, the liquid returns to the wicking block 639, as indicated by the curved arrow. To enhance condensation, a heatsink 638 contacts and cools the upper plate 632. The heatsink 638 can be an air- or liquid-cooled heatsink. Therefore, in this embodiment, the bottom of each secondary channel 622 extracts heat from the chip, and the top of each channel requires liquid or air cooling to enable condensation.

[0079] In the optional embodiment indicated by the dotted line, the secondary cooling channels are formed as 3D vapor chambers. Each channel is an independent autonomous cooling unit, which includes an evaporation chamber 642 and an evaporator-condenser tube 644 attached to a cooling plate 646. When the liquid in the evaporation chamber 642 becomes hot, the liquid evaporates and rises in the tube 644. The tube is cooled by the plate 646, which also acts as a condenser, with the plate serving as fins. The condensed liquid returns to the evaporation chamber 642. Therefore, in this embodiment, coolant is supplied and returned only from the main cooling channel 612, and there is no supply and return line to the secondary cooling channels 622, as they are independent.

[0080] This disclosure typically provides a cold plate comprising a heat-conducting plate assembly incorporating a first set of cooling channels and a second set of cooling channels, and further having an inlet port for delivering cooling fluid to the first set of cooling channels, and a return port for removing vapor from the first set of cooling channels. The second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels. The second set of cooling channels includes a plurality of isolated, independently sealed chambers, each forming a two-phase evaporation and condensation chamber. Each isolated, independently sealed chamber may include a wicking block.

[0081] It is understandable that the heat dissipation rates and capabilities of the primary and secondary channels can differ. Therefore, the heat dissipation of the cold plate is uneven across its surface. In some applications, this uneven heat dissipation is acceptable or even desirable. However, there are applications where uniform heat dissipation is desired. Figure 7 The document illustrates an implementation method for improving heat dissipation uniformity.

[0082] Figure 7 This is a top view of the cold plate 703. The cold plate 703 can be any of the embodiments shown herein and has a main channel 712 (which may include fins 736) and a secondary channel 722. Additionally, a heat radiator 752 is incorporated on each side of the cold plate 703, which may be, for example, a heat-conducting plate, such as a copper plate. The heat radiator 752 is used to diffuse heat between the two different cooling channels, thereby making the heat uniform on the surface of the cold plate 703. Furthermore, when the secondary channel is not in operation, heat from the area below the secondary channel can be removed by the main channel because the heat will be conducted by the heat radiator 752. Conversely, if the cooling system of the main channel fails and the secondary channel operates as standby capacity, heat from the area below the inactive main channel will be conducted to the secondary channel by the heat radiator 752.

[0083] Therefore, a cold plate is typically provided, including a heat-conducting plate assembly that incorporates a first set of cooling channels and a second set of cooling channels, and further having an inlet port for delivering cooling fluid to the first set of cooling channels and a return port for removing vapor from the first set of cooling channels, wherein the second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels, and wherein the cold plate assembly also includes at least one heat radiator in physical contact with the first set of cooling channels and the second set of cooling channels.

[0084] Figure 8This is a top view of the cooling plate, illustrating the method of generating cooling fluid flow in the main and secondary channels. In this figure, the fluid flow in the secondary channel is opposite to the flow direction in the main channel, but the flow can also be in the same direction. Moreover, in some embodiments, the fluid manifold can be integrated into the heat radiator. The fluid flow in the main cooling channel 812 is indicated by dashed arrows, while the fluid flow in the secondary cooling channel 822 is indicated by dotted-dash arrows. Fins 836 enhance the heat collection of the cooling fluid in the main channel 812.

[0085] Figure 9 This is a schematic diagram illustrating an example of a cooling system utilizing a multi-channel cold plate 903 according to an embodiment disclosed herein. While the cold plate 903 can be constructed according to any embodiment disclosed herein, in… Figure 9 In the example, the cold plate 903 incorporates a main cooling channel operating on a thermosiphon two-phase pumpless thermal cycle, while the secondary cooling channel operates on a phase change pumped thermal cycle. Of course, this is merely an example, and other thermal cycles can be used.

[0086] exist Figure 9 In this system, cooling fluid is supplied from condenser 970 to inlet port 910 of cold plate 903 via inlet line 972. The cooling fluid flowing in inlet line 972 can be any liquid coolant selected from standard coolants. The cooling fluid flowing in main cooling channel 912 is converted into vapor, and the vapor returns to condenser 970 from outlet 916 via return line 974. Similarly, cooling fluid is pumped from subcondenser 980 to inlet port 920 of cold plate by pump 988 via inlet line 982. The cooling fluid flows and evaporates in secondary channel 922. The vapor returns to condenser 980 from outlet 923 via return line 982. By activating the pump, the secondary cooling system is powered on, either as backup cooling or to enhance heat dissipation as needed.

[0087] As can be seen, a cooling system for a microchip is disclosed, comprising: a cold plate assembly incorporating a first set of cooling channels and a second set of cooling channels, wherein the second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels; a main condenser; a main supply line fluidly connected between the main condenser and the first set of cooling channels; and a main return line fluidly connected between the main condenser and the first set of cooling channels. The system may further include: a secondary condenser; a secondary supply line fluidly connected between the secondary condenser and the first set of cooling channels; a pump connected to the secondary supply line; and a secondary return line fluidly connected between the secondary condenser and the first set of cooling channels. Optionally, the second set of cooling channels includes multiple isolated, independently sealed chambers, each forming a two-phase evaporation and condensation chamber.

[0088] Figure 10 The operation of a multi-channel system is illustrated, in which two separate cooling systems operating on the same cold plate employ two thermal cycles. As indicated in 10, in this particular embodiment, the primary system utilizes a pump-free thermal cycle, such as a thermosiphon cycle. The secondary system utilizes a pumped phase-change thermal cycle. As indicated in 12, during normal operation, the pumps are off (i.e., idle), and circulation in both systems occurs naturally via convection. When enhanced or standby cooling is required, as indicated in 14, the pumps are energized to mechanically force fluid into the secondary cooling channels. According to the indication in 16, the boiling point of the coolant in the secondary system should be lower than that of the coolant in the primary cooling system.

[0089] Therefore, through the disclosed embodiments, a microchip cold plate is provided, having a first set of cooling fluid channels and a second set of fluid channels, wherein the second set of fluid channels is fluidly isolated from the first set of fluid channels, preventing cooling fluid from the first set of cooling channels from entering the second set of fluid channels, and preventing cooling fluid flowing in the second set of cooling channels from entering the first set of fluid channels. The cooling channels in the first set of cooling channels may intersect with the cooling channels in the second set of fluid channels.

[0090] According to another embodiment, the inlet manifold distributes cooling fluid between the cooling channels of the first group, and the return manifold collects steam from the cooling channels of the first group and directs the steam to the condenser. The cooling channels in the second group can be independent two-phase chambers, or they can have a cooling fluid inlet and a steam outlet. When the second group of cooling channels includes a fluid inlet and a steam outlet, it is desirable to include a pump to deliver cooling fluid to the second group of cooling channels.

[0091] According to the disclosed embodiments, a microchip cooling system is provided, including a main condenser; a cold plate includes multiple main cooling channels and multiple secondary cooling channels, the secondary cooling channels being fluidly isolated from the main cooling channels; a main inlet pipe is connected between the inlet ports of the main condenser and the main cooling channels, and a return pipe is connected between the outlet ports of the main condenser and the main cooling channels.

[0092] In the foregoing description, embodiments of the invention have been described with reference to specific exemplary embodiments. However, it will be apparent that various modifications can be made without departing from the broader spirit and scope of the invention as set forth in the appended claims. Therefore, the description and drawings should be considered illustrative rather than restrictive.

Claims

1. A cold plate for cooling a microchip, comprising a heat-conducting plate assembly, the heat-conducting plate assembly having a first set of cooling channels and a second set of cooling channels, and further having an inlet port and a return port, wherein the inlet port is for delivering cooling fluid to the first set of cooling channels, the return port is for removing vapor from the first set of cooling channels, and wherein, The second set of cooling channels is fluidly isolated from the first set of cooling channels, thereby preventing the cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels; The heat-conducting plate assembly includes: a contact plate; an upper plate; and a core sandwiched between the contact plate and the upper plate, wherein a first set of cooling channels and a second set of cooling channels are formed within the core; the core includes alternating ridges and grooves forming corrugations. The second set of cooling channels is the main cooling system, which needs to operate continuously. The first set of cooling channels is the secondary cooling system, which only operates when additional cooling is needed or when the main cooling system fails. The first set of cooling channels is configured for pumping two-phase cooling, and the second set of cooling channels is configured for a pumpless single-loop thermosiphon cooling thermal cycle, wherein the thermal cycle of the second set of cooling channels is different from the thermal cycle of the first set of cooling channels. The second set of cooling channels includes multiple isolated, independently sealed chambers, each forming a two-phase evaporation and condensation chamber.

2. The cold-rolled plate according to claim 1, wherein, Each side of the cold plate is fitted with a heat radiator, which is used to diffuse heat between two different cooling channels to make the heat uniform on the surface of the cold plate.

3. The cold-rolled plate according to claim 2, wherein, Each of the isolated, individually sealed cavities includes a wicking block.

4. The cold-rolled plate according to claim 1, wherein, The first set of cooling channels includes multiple secondary cooling channels connected to the cooling fluid inlet and return outlet.

5. The cold-rolled plate according to claim 1, wherein, Each of the cooling channels in the first group includes fins, and each of the cooling channels in the second group does not have fins.

6. The cold-rolled plate according to claim 1, wherein, The cooling channels in the first group of cooling channels are interleaved with the cooling channels in the second group of cooling channels.

7. The cold-rolled plate according to claim 6, wherein, The cross-section of the cooling channel in the first group of cooling channels has a different size than the corresponding cross-section of the cooling channel in the second group of cooling channels.

8. The cold-rolled plate according to claim 6, wherein, The coverage area of ​​the cooling channel in the first group of cooling channels has a different size than the corresponding coverage area of ​​the cooling channel in the second group of cooling channels.

9. The cold-rolled plate according to claim 1, wherein, The heat-conducting plate assembly further includes a main cooling fluid supply manifold, which is formed in one of the contact plate or the upper plate.

10. The cold-rolled plate according to claim 9, wherein, The corrugations are skewed, causing the cooling channels in the first group of cooling channels to have different dimensions than the cooling channels in the second group of cooling channels.

11. The cold plate according to claim 9, wherein the main cooling fluid supply manifold is fluidly connected to the first set of cooling channels.

12. The cold-rolled steel plate according to any one of claims 1-11, wherein, The second set of cooling channels includes a secondary fluid that is different from the cooling fluid delivered to the first set of cooling channels.

13. A cooling system for cooling a microchip, comprising: A cold plate assembly, wherein the cold plate assembly is combined with a first set of cooling channels and a second set of cooling channels, wherein the second set of cooling channels is fluidly isolated from the first set of cooling channels to prevent cooling fluid from the first set of cooling channels from flowing into the second set of cooling channels; Main condenser; A main supply line, which is fluidly connected between the main condenser and the first set of cooling channels; A main return line, which is fluidly connected between the main condenser and the first set of cooling channels; The cold plate assembly includes: a contact plate; an upper plate; and a core, the core being sandwiched between the contact plate and the upper plate; wherein the first set of cooling channels and the second set of cooling channels are formed within the core; The second set of cooling channels is the main cooling system, which needs to operate continuously. The first set of cooling channels is the secondary cooling system, which only operates when additional cooling is needed or when the main cooling system fails. The first set of cooling channels is configured for pumping two-phase cooling, and the second set of cooling channels is configured for a pumpless single-loop thermosiphon cooling thermal cycle, wherein the thermal cycle of the second set of cooling channels is different from the thermal cycle of the first set of cooling channels. The second set of cooling channels includes multiple isolated, independently sealed chambers, each of which forms a two-phase evaporation and condensation chamber.

14. The cooling system according to claim 13, further comprising: Secondary condenser; A secondary supply line is fluidly connected between the secondary condenser and the first set of cooling channels; Pump, the pump being connected to the secondary supply line; as well as The secondary return line is fluidly connected between the secondary condenser and the first set of cooling channels.

15. The cooling system according to claim 13, wherein, Each side of the cold plate is fitted with a heat radiator, which is used to diffuse heat between two different cooling channels to make the heat uniform on the surface of the cold plate.

16. The cooling system according to claim 15, further comprising: At least one inlet manifold is formed in one of the contact plate or the upper plate; and at least one return manifold, the at least one return manifold being formed in one of the contact plate or the upper plate.

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