Microchannel cold plate and heat dissipation system

Abstract

This application relates to a microchannel cold plate and a heat dissipation system. The microchannel cold plate includes: a substrate; a cooling channel extending through the substrate along its length, with inlets and outlets formed at opposite ends of the cooling channel; wherein multiple cooling channels are provided, arranged in parallel along the width of the substrate, and the inlets of the cooling channels are independently arranged; in this application, the cooling channels extend linearly along the length of the substrate, and multiple cooling channels are arranged along the width of the substrate to form an array of short-pitch, straight-through flow channels. After the coolant is injected from each inlet, it flows short and straight through its respective cooling channel to the outlet, reducing the temperature rise of the coolant. Throughout the flow process within the microchannel cold plate, it maintains efficient heat dissipation capacity, improving the uniformity of the chip surface temperature; the flow resistance of the coolant is significantly reduced, reducing the demand for coolant supply pressure.

Description

Technical Field

[0001] This application relates to the field of heat dissipation technology for electronic devices, specifically to a microchannel cold plate and heat dissipation system. Background Technology

[0002] Microchannel cold plates are high-efficiency heat dissipation devices with internally processed micron-sized fluid cooling channels. Compared with traditional cold plates, microchannel cold plates have a significantly improved convective heat transfer coefficient, making them suitable for high-performance computing chips with extremely high power density.

[0003] However, in existing microchannel cold plates, the micro-cooling channels are often long cooling channels that extend continuously from the inlet to the outlet and repeatedly turn back to cover the entire chip area. However, when the coolant flows along the channel, the flow path is long and the temperature rise of the coolant along the way is significant, resulting in poor heat dissipation performance of the microchannel cold plate, uneven temperature distribution on the chip surface, and large pressure loss along the way. It also requires a high supply pressure of coolant and is prone to further weakening the heat dissipation effect due to insufficient supply pressure. Utility Model Content

[0004] The technical problem to be solved by this application is to provide a microchannel cold plate and heat dissipation system, which can effectively improve heat dissipation performance and chip temperature uniformity, and reduce the requirements for coolant supply pressure.

[0005] According to a first aspect of the present application, a microchannel cold plate is provided, comprising: a substrate; a cooling channel extending through the substrate along its length, and an inlet and an outlet formed at opposite ends of the cooling channel; wherein, multiple cooling channels are provided, the multiple cooling channels are arranged in parallel along the width direction of the substrate, and the inlets of the cooling channels are independently arranged to form an array of straight-through flow channels; the array of straight-through flow channels is adapted to allow coolant to be injected from the inlet and then flow straight through the corresponding cooling channel to the outlet.

[0006] In one embodiment, a partition is provided in the cooling channel, the partition extending along the length of the substrate and connected to the inner wall of the cooling channel to divide the cooling channel into multiple flow channels.

[0007] In one embodiment, at least two flow channels are provided within the cooling channel along the thickness direction of the substrate.

[0008] In one embodiment, a baffle plate is provided on the inner wall of the flow channel, and the baffle plate is arranged parallel to the length direction of the substrate.

[0009] In one embodiment, a plurality of the baffles are spaced apart along the length of the substrate to form a baffle bar; the baffle bar is provided in multiple spaces along the width of the substrate.

[0010] In one embodiment, the baffle is made of a porous material.

[0011] In one embodiment, a gap is left between the first end of the partition along the length direction of the substrate and the inlet.

[0012] In one embodiment, the outlets of each of the cooling channels are interconnected.

[0013] In one embodiment, the substrate is covered with a thermally conductive layer on at least one side of its thickness direction. According to a second aspect of the embodiments of this application, a heat dissipation system is provided, comprising: a coolant supply source; a microchannel cold plate as described in any of the preceding claims; wherein the coolant supply source is connected to the inlet of each of the cooling channels via multiple pipelines, and a flow valve is provided at each pipeline.

[0014] Compared with existing technologies, the microchannel cold plate provided in this embodiment has cooling channels that extend linearly along the length of the substrate, and multiple cooling channels are arranged along the width of the substrate to form an array of short-pitch, straight-through flow channels. After the coolant is injected from each inlet, it flows straight through its respective cooling channel to the outlet. On the one hand, the temperature rise of the coolant is reduced, and it maintains efficient heat dissipation capacity throughout its flow within the microchannel cold plate. Compared with traditional cold plates, it has higher heat dissipation performance at the same flow rate and improves the uniformity of chip surface temperature. On the other hand, the flow resistance of the coolant is significantly reduced, thereby reducing the demand for coolant supply pressure, avoiding the impact of insufficient coolant supply pressure on heat dissipation performance, and reducing system operating energy consumption. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a microchannel cold plate.

[0016] Figure 2 This is a schematic diagram of a microchannel cold plate.

[0017] Figure 3 This is a schematic diagram of a microchannel cold plate.

[0018] Figure 4 This is a schematic diagram showing the interaction between the microchannel cold plate and the chip.

[0019] Figure 5 This is a schematic diagram of the structure of a traditional cold plate in existing technology.

[0020] Figure 6 This is a schematic diagram of the temperature distribution of chips under a traditional cold plate in existing technology.

[0021] Figure 7 This is a schematic diagram of the temperature distribution of the chip under the microchannel cold plate in this embodiment.

[0022] Figure 8 This is a schematic diagram of the pressure distribution in a traditional cold plate in existing technology.

[0023] Figure 9 This is a schematic diagram of the pressure distribution of the microchannel cold plate in this embodiment.

[0024] Explanation of reference numerals in the attached figures 1. Substrate; 2. Cooling channel; 21. Inlet; 22. Outlet; 23. Baffle; 24. Flow channel; 25. Baffle plate; 3. Thermal conductive layer; 4. Chip; 5. Traditional cold plate; 51. Liquid cooling channel. Detailed Implementation

[0025] Unless otherwise defined, the technical or scientific terms used in this specification and claims shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. Specific embodiments of this application will be described below in conjunction with the accompanying drawings. It should be noted that, in order to provide a concise description, this specification cannot exhaustively describe all features of the actual embodiments. Without departing from the spirit and scope of this application, those skilled in the art can modify and substitute the embodiments of this application, and the resulting embodiments are also within the protection scope of this application.

[0026] refer to Figures 1 to 9 This application provides a microchannel cold plate, comprising: a substrate 1; a cooling channel 2 extending through the substrate 1 along its length, with an inlet 21 and an outlet 22 formed at opposite ends of the cooling channel 2; wherein multiple cooling channels 2 are provided, arranged in parallel sequence along the width direction of the substrate 1, and the inlets 21 of the cooling channels 2 are independently arranged to form an array of straight-through flow channels; the array of straight-through flow channels is suitable for allowing coolant to be injected from the inlet 21 and then flow straight through the corresponding cooling channel 2 to the outlet 22; it should be noted that the length direction of the substrate 1 is perpendicular to the width direction, i.e. Figure 1 The substrate 1 also has the following orientation: as shown; Figure 1 The thickness direction shown is perpendicular to the plane containing the length and width directions; one side of the substrate 1 along the thickness direction is used to bond with the chip 4 for heat exchange.

[0027] Specifically, in use, the microchannel cold plate has substrate 1 bonded to chip 4, and coolant flowing through cooling channels 2 to exchange heat with chip 4; among other things, compared to... Figure 5In the conventional cold plate 5, the liquid cooling channel 51 is arranged in an S-shaped meandering pattern. In the microchannel cold plate provided in this embodiment, the cooling channel 2 extends linearly along the length direction of the substrate 1, and multiple cooling channels 2 are arranged along the width direction of the substrate 1 to form an array of straight-through flow channels. This allows the coolant to be injected from each inlet 21 and then flow directly to the outlet 22 along its respective cooling channel 2 in a short distance. On the one hand, the temperature rise of the coolant is greatly reduced, and the heat dissipation capacity is maintained throughout the flow process in the microchannel cold plate. Compared with the conventional cold plate 5, the heat dissipation performance is higher at the same flow rate, and the uniformity of the surface temperature of the chip 4 is improved. On the other hand, the flow resistance of the coolant is significantly reduced, thereby reducing the demand for coolant supply pressure, which greatly reduces the system pump power demand, avoids the reduction in heat dissipation performance caused by insufficient coolant supply pressure, and greatly reduces the system operating energy consumption. In addition, the straight-through flow channel makes the coolant flow velocity uniform, avoiding the sudden change in local flow velocity and eddy phenomenon caused by the bend in the flow channel in the conventional cold plate 5, thereby reducing the hot spot effect caused by uneven local flow velocity and improving the heat dissipation uniformity and heat dissipation performance.

[0028] Furthermore, the inlets 21 of each cooling channel 2 are independent of each other, so that the coolant flow rate can be set individually for each cooling channel 2 according to the heat distribution difference of the chip 4 along the width direction of the substrate 1; a larger flow rate is allocated to the cooling channel 2 corresponding to the high heat flux density area, and a smaller flow rate is allocated to the cooling channel 2 corresponding to the low heat flux density area, so that the temperature distribution on the surface of the chip 4 is more uniform, and the heat dissipation performance of the microchannel cold plate is further improved.

[0029] It should be added that... Figure 5 The simulation results of the conventional cold plate 5 shown below and the microchannel cold plate provided in this embodiment are shown in the table below:

[0030] It should be noted that both the conventional cold plate 5 and the microchannel cold plate of this embodiment are made of diamond-copper composite material; the unit of total coolant flow rate cfm refers to cubic feet per minute, which is used to express the volume flow rate of gas or liquid passing through a certain cross section per unit time; the unit of coolant pressure drop in H2O refers to inches of water column, which is used to express the pressure loss, that is, the pressure drop of coolant from inlet 21 to outlet 22.

[0031] As can be seen from the table above, under the premise that all parameters are the same, compared with the traditional cold plate 5, the microchannel cold plate provided in this embodiment reduces the temperature of chip 4 by 7.1°C due to the use of array and straight-through flow channels, and greatly improves the heat dissipation performance; the cooling pressure drop is reduced by 20.55 in H2O, and the coolant flow resistance is smaller.

[0032] Furthermore, Figure 6 This is a temperature distribution diagram of chip 4 under a traditional cold plate 5. Figure 7This is a temperature distribution diagram of chip 4 under the microchannel cold plate in this embodiment. As can be seen from the comparison, under the traditional cold plate 5, chip 4 has a significant high-temperature area, with the highest temperature approaching 70°C; while under the microchannel cold plate in this embodiment, the surface temperature of chip 4 is significantly reduced, with the overall temperature between 50°C and 60°C, and the temperature distribution is more uniform. In addition, the temperature of the microchannel cold plate itself in this embodiment is also significantly reduced. The highest temperature of the traditional cold plate 5 is close to 100°C, while the temperature of the microchannel cold plate in this embodiment is between 60°C and 80°C, which is significantly lower than that of the traditional cold plate 5.

[0033] Furthermore, Figure 8 This is the pressure distribution diagram of a traditional cold-rolled plate 5. Figure 9 This is a pressure distribution diagram of the microchannel cold plate in this embodiment. As can be seen from the comparison, the traditional cold plate 5 has a large pressure loss, with the inlet pressure at 21 being about 33 in H2O and dropping to negative pressure near the outlet at 22, resulting in an overall pressure drop of more than 35 in H2O. This leads to extremely high resistance to coolant flow and places very high demands on the supply pump. In contrast, the inlet pressure of the microchannel cold plate in this embodiment is only about 2.1 in H2O, and the outlet pressure at 22 is about -0.2 in H2O, with an overall pressure drop of only 2.3 in H2O. This is significantly lower than that of the traditional cold plate 5, greatly reducing the resistance to coolant flow. Furthermore, the system can use a supply pump with a lower head, reducing energy consumption and operating costs.

[0034] In one embodiment, a partition 23 is provided in the cooling channel 2. The partition 23 extends along the length of the substrate 1 and is connected to the inner wall of the cooling channel 2 to divide the cooling channel 2 into multiple flow channels 24. In this embodiment, the partition 23 divides the cooling channel 2 into at least two independent and parallel flow channels 24. After the coolant enters from the inlet 21 of each cooling channel 2, it is forced to flow into different flow channels 24 by the partition 23, so that the original flow along a single path is transformed into multiple parallel flows. The coolant in each flow channel 24 exchanges heat with the corresponding chip 4 area, ensuring that the heat exchange performance of the coolant is maximized and further improving the heat exchange efficiency of the coolant.

[0035] In one embodiment, at least two flow channels 24 are provided in the cooling channel 2 along the thickness direction of the substrate 1. In this embodiment, at least two layers of flow channels 24 are provided along the thickness direction of the substrate 1, so that both sides of the substrate 1 along the thickness direction can contact the chip 4 for heat exchange. During heat exchange, the flow channel 24 closest to the chip 4 (hereinafter referred to as the main heat exchange channel) undertakes the main heat dissipation task and absorbs the heat of the chip 4. The flow channel 24 located on the side of the main heat exchange channel away from the chip 4 (hereinafter referred to as the auxiliary heat exchange channel) performs heat exchange and cooling on the main heat exchange layer, so as to avoid the main heat exchange channel from degrading its heat dissipation performance due to excessive temperature rise and ensure that the main heat exchange channel always maintains good heat exchange performance.

[0036] Optionally, in this embodiment, the partition 23 is a cross-shaped plate that divides the cooling channel 2 into multiple rectangular sub-channels to form a grid-like sub-channel array. Furthermore, each sub-channel 24 has the same cross-sectional area, ensuring that the coolant flows at a uniform speed and has a balanced pressure within each sub-channel 24.

[0037] In one embodiment, a baffle plate 25 is provided on the inner wall of the flow channel 24, and the baffle plate 25 is arranged parallel to the length direction of the substrate 1. In this embodiment, the baffle plate 25 is used to increase local disturbance during the flow of coolant, destroy the flow boundary layer, and promote the generation of secondary flow and vortex in the fluid, thereby enhancing the convective heat transfer between the coolant and the wall of the flow channel 24 and further improving the heat transfer performance.

[0038] In one embodiment, multiple baffles 25 are spaced apart along the length of the substrate 1 to form a baffle bar; multiple baffle bars are spaced apart along the width of the substrate 1; in this embodiment, the baffles 25 are fin-shaped and all the baffles 25 are arranged in an array; when the coolant flows along the length of the flow channel, it flows through each fin in sequence, generating local flow around each fin, and the multiple fins cooperate with each other to further disrupt the flow boundary layer.

[0039] In one embodiment, the baffle 25 is made of a porous material; in this embodiment, the porous material can be a sintered copper powder porous medium or foamed copper metal; the porous material has tiny pores, and when the coolant flows through the baffle 25, in addition to generating disturbance to break the boundary layer and enhance convective heat transfer, the capillary force of the tiny pores can also cause the coolant to be drawn into the pores; the coolant drawn into the pores spreads inside and on the surface of the baffle 25 and continuously replenishes the wall of the distribution channel 24, enhancing the stability of heat transfer.

[0040] Optionally, based on the porous baffle 25, the microchannel cold plate has the ability to be packaged as a two-phase heat exchange plate. That is, by sealing, evacuating and injecting phase change working fluid, the porous baffle 25 is used as a liquid wick, and the capillary force is used to drive the condensate back to achieve gas-liquid two-phase circulation heat dissipation.

[0041] In one embodiment, a gap is left between the first end of the partition 23 along the length of the substrate 1 and the inlet 21. After the coolant enters from the inlet 21, it first flows a certain distance in the cooling channel 2 (i.e., the gap between the first end and the inlet 21), and then enters each of the branch channels 24 separated by the partition 23. This avoids the coolant directly impacting the end of the partition 23 and causing local eddies, making the inlet flow of each branch channel 24 more consistent and improving the uniformity and stability of the overall heat exchange.

[0042] In one embodiment, the outlets 22 of each cooling channel 2 are interconnected, so that the coolant flowing out of each cooling channel 2 converges and mixes in the outlet 22 area. The temperature of the coolant after heat exchange tends to be consistent, and then it flows back to the coolant supply source in a unified manner, which is conducive to the stable control of system temperature and avoids thermal stress caused by local temperature difference after recirculation.

[0043] Optionally, in this embodiment, a confluence channel is formed between the outlet 22 of the cooling channel 2 and the end of the substrate 1. One side of the confluence channel is connected to the outlet 22 of each cooling channel 2, and the other side is connected to the coolant supply source through a pipeline, which effectively reduces the confluence resistance and ensures that the coolant flows back smoothly after heat exchange.

[0044] In one embodiment, a thermally conductive layer 3 is applied to at least one side of the substrate 1 along its thickness direction. In this embodiment, when the microchannel cold plate is used, the thermally conductive layer 3 is sandwiched between the substrate 1 and the chip 4. In this embodiment, the thermally conductive layer 3 can be an indium sheet, which can be fixed to the chip 4 and the substrate 1 by a reflow soldering process at a soldering temperature of about 260°C. Due to the excellent ductility and thermal conductivity of the indium sheet, it can fully fill the microscopic gap between the chip 4 and the substrate 1 during the reflow soldering process, forming a dense metal bonding interface, thereby significantly reducing the contact thermal resistance between the chip 4 and the substrate 1. Compared with the traditional packaging scheme that uses a heat sink and multiple layers of thermally conductive interface materials, this embodiment directly solders the chip 4 and the microchannel cold plate together with the indium sheet, eliminating the need for a heat sink and the thermally conductive interface layers on both sides, significantly shortening the path of heat transfer from the chip 4 to the coolant, further reducing the overall thermal resistance and improving the heat dissipation efficiency.

[0045] In a second aspect, this application provides a heat dissipation system, including: a coolant supply source; a microchannel cold plate as described above; the coolant supply source is connected to the inlet 21 of each cooling channel 2 via multiple pipelines, and flow valves are provided at the pipelines; in this embodiment, by adjusting the opening of each flow valve, according to the distribution difference of the heat source on the surface of the chip 4 along the width direction of the substrate 1, a larger coolant flow rate is allocated to the cooling channel 2 corresponding to the high heat flux density area, and a smaller coolant flow rate is allocated to the low heat flux density area, so as to achieve on-demand coolant supply.

[0046] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. A micro-channel cold plate characterized by, include: substrate; A cooling channel is provided through the substrate along its length, and an inlet and an outlet are formed at opposite ends of the cooling channel. The cooling channel is provided with multiple channels, which are arranged in parallel along the width direction of the substrate, and the inlets of the cooling channels are independently set to form an array of straight-through flow channels. The array of straight-through flow channels is adapted to allow coolant to flow directly from the inlet to the outlet along the corresponding cooling channel after being injected.

2. The microchannel cold plate as described in claim 1, characterized in that, The cooling channel is provided with a partition that extends along the length of the substrate and is connected to the inner wall of the cooling channel to divide the cooling channel into multiple flow channels.

3. The microchannel cold plate as described in claim 2, characterized in that, Within the cooling channel, at least two flow channels are provided along the thickness direction of the substrate.

4. The microchannel cold plate as described in claim 2, characterized in that, A baffle plate is provided on the inner wall of the flow channel, and the baffle plate is arranged parallel to the length direction of the substrate.

5. The microchannel cold plate as described in claim 4, characterized in that, Multiple baffles are spaced apart along the length of the substrate to form a baffle bus. The baffles are provided in multiple rows at intervals along the width direction of the substrate.

6. The microchannel cold plate as described in claim 4, characterized in that, The baffle is made of a porous material.

7. The microchannel cold plate as described in claim 2, characterized in that, There is a gap between the first end of the partition along the length of the substrate and the inlet.

8. The microchannel cold plate as described in claim 1, characterized in that, The outlets of each of the cooling channels are interconnected.

9. The microchannel cold plate as described in claim 1, characterized in that, The substrate is covered with a thermally conductive layer on at least one side of its surface along the thickness direction.

10. A heat dissipation system, characterized in that, include: Coolant supply source; The microchannel cold plate as described in any one of claims 1 to 9 above; The coolant supply source is connected to the inlet of each of the cooling channels through multiple pipelines, and a flow valve is provided at each pipeline.

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