Two-phase heat dissipation cold plate and system for heat dissipation of high-power chip

Abstract

The invention relates to a two-phase heat dissipation cold plate and system for heat dissipation of a high-power chip, and belongs to the technical field of heat dissipation of electronic equipment.The two-phase heat dissipation cold plate comprises a bottom plate, a cover plate, a liquid inlet and a liquid outlet, the bottom plate and the cover plate are connected in a sealed mode to form an inner cavity, and a plurality of rows of heat dissipation ribs are arranged in the inner cavity; the plurality of rows of radiating ribs are arranged at intervals in a multi-row manner in the working medium flowing direction from the liquid inlet to the liquid outlet, and a main runner is formed between every two adjacent radiating ribs; the height of at least part of the sections of each row of radiating ribs is gradually reduced in the working medium flowing direction, so that a connecting flow channel which is used for connecting two adjacent rows of main flow channels and is gradually increased in cross section area is formed; fluid mixing flow channels are reserved in the heat dissipation ribs at equal intervals, and the fluid mixing flow channels and the connecting flow channels can be used for disturbing flowing of fluid in the adjacent main flow channels. While excellent fluid expansion adaptability and enhanced heat exchange capacity are guaranteed, regularization and flattening of the cold plate structure are achieved, and the cold plate has the advantage of being low in manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for electronic devices, and in particular to a two-phase heat dissipation plate and system for high-power chip heat dissipation. Background Technology

[0002] As chip power density continues to rise, traditional single-phase liquid cooling technology has reached a bottleneck in handling high heat flux density heat dissipation demands exceeding 500W due to the limited specific heat capacity of the working fluid. Pump-driven two-phase cooling technology utilizes the latent heat of phase change of the working fluid, enabling the transfer of a large amount of heat at a relatively low temperature difference, making it a superior solution. However, existing two-phase heat sinks often face the challenge of balancing enhanced heat transfer with the need to accommodate the volume expansion of the working fluid in their structural design.

[0003] Chinese invention patent CN120878656A discloses a two-phase cold plate with variable thickness. It adapts to the volume expansion of the working fluid after vaporization by gradually increasing the height of the entire flow channel along the flow direction (i.e., gradually expanding the channel cross-section). While this helps reduce flow pressure drop, this structure results in irregularly shaped internal cavities (such as wedge-shaped cavities). These irregular cavities are difficult and costly to manufacture (e.g., CNC machining, mold development, or welding assembly), and hinder the precise forming of complex internal rib structures, thus limiting further performance improvements and large-scale application.

[0004] Therefore, there is an urgent need for a two-phase heat dissipation cold plate that can maintain excellent heat dissipation performance and reduce flow resistance while having a more regular and easier-to-manufacture internal cavity structure. Summary of the Invention

[0005] To address the shortcomings in the aforementioned background technology, this invention proposes a two-phase heat dissipation cold plate and system for high-power chip heat dissipation. It aims to solve the problems of high processing complexity and high manufacturing cost caused by the irregular flow channels used in existing two-phase cold plates to accommodate volume expansion, while ensuring efficient heat exchange and smooth working fluid output.

[0006] The technical solution of this invention is implemented as follows: A two-phase heat dissipation plate for high-power chip heat dissipation includes a base plate, a cover plate, an inlet, and an outlet. The base plate and the cover plate are sealed together to form an internal cavity. The inlet and outlet are connected to the internal cavity. The internal cavity is provided with several rows of heat dissipation ribs. The several rows of heat dissipation ribs are arranged in multiple rows at intervals along the working fluid flow direction from the inlet to the outlet, and a main flow channel is formed between adjacent heat dissipation ribs. The height of at least a portion of each row of heat dissipation ribs gradually decreases along the working fluid flow direction, thereby forming a connecting flow channel that connects two adjacent main flow channels and has a gradually increasing cross-sectional area. The heat dissipation ribs are provided with through openings at equal intervals to connect the two main flow channels. A fluid mixing flow channel is formed at the through opening. The extension direction of the fluid mixing flow channel is at a non-zero angle with the working fluid flow direction. Both the fluid mixing flow channel and the connecting flow channel can be used to disturb the fluid flow in the adjacent main flow channels.

[0007] Preferably, the heat dissipation rib includes a straight rib unit, the length extension direction of the straight rib unit is parallel to the working fluid flow direction, the bottom of the straight rib unit is fixedly connected to the inner wall surface of the base plate, and the top highest point or the top surface of the top section is in contact with the inner wall surface of the cover plate.

[0008] Preferably, the height of at least some segments of the heat dissipation ribs gradually decreases along the working fluid flow direction in a stepped, linear, or curved manner. The heat dissipation ribs are integrally formed with the base plate. The internal cavity is a cubic opening formed at the bottom of the cover plate.

[0009] Preferably, the diameter of the inlet is smaller than the diameter of the outlet, in order to adapt to the volume change characteristics of the working fluid before and after it is in a single-phase liquid state at the inlet and a two-phase gas-liquid state at the outlet.

[0010] Preferably, both the liquid inlet and the liquid outlet are located on the cover plate. The liquid inlet is connected to a distribution chamber located at the liquid inlet end of the internal cavity, and the liquid outlet is connected to a collection chamber located at the liquid outlet end of the internal cavity. The outer wall surface of the base plate is a heat-absorbing mounting surface for contacting the heating surface of a high-power chip, and the projected area of ​​the heat dissipation ribs covers the chip contact area of ​​the heat-absorbing mounting surface.

[0011] A two-phase heat dissipation system includes a two-phase heat dissipation plate for high-power chip heat dissipation as described above. An inlet and an outlet are connected by a pipe. A pumping device and a condenser are installed on the pipe. The pumping device drives the working fluid to circulate along the pipe. The working fluid is deionized water or a fluorinated liquid.

[0012] The beneficial effects of this invention are:

[0013] The core innovation of this invention lies in creating space to accommodate the expansion of the working fluid by changing the height of the heat dissipation ribs rather than the depth of the cover plate cavity. This allows the internal cavity formed by the cover plate and the bottom plate on the cold plate to be designed as a regular cuboid or cube shape. The design of the cavity structure as a regular shape greatly simplifies the processing technology, makes processing more convenient, makes the precision easier to control, and increases the yield rate, thereby effectively reducing production costs.

[0014] Simultaneously, this invention achieves a synergistic effect of highly efficient heat exchange and smooth heat dissipation. By employing a "gradually decreasing height of the heat dissipation ribs," a connecting flow channel with a gradually increasing cross-sectional area is formed within a limited space. Its physical function is the same as that of an irregularly expanding flow channel, providing smooth expansion space for the downstream vaporized two-phase working fluid, effectively reducing flow pressure drop and the risk of flow instability. Furthermore, the fluid mixing channel formed by the through-openings on the heat dissipation ribs strongly disturbs the working fluid in adjacent main flow channels, enhancing lateral mixing, disrupting the thermal boundary layer, and significantly strengthening boiling heat transfer. The combination of these two aspects achieves heat dissipation performance within a regular cavity that is comparable to, and even superior to, that of an irregularly shaped flow channel cold plate.

[0015] Furthermore, the present invention, through its design of a small inlet and a large outlet, accommodates the volume change of the working fluid after phase change, which helps to balance the system pressure. The regular overall structure also facilitates standardized connection and integration with the dispensing chamber, collecting chamber, and other system components, resulting in superior system adaptability. Attached Figure Description

[0016] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional perspective structural diagram of the present invention;

[0018] Figure 2 This is a perspective view of the side structure of the present invention;

[0019] Figure 3 This is a perspective view of the cover plate structure of the present invention;

[0020] Figure 4 This is a schematic diagram of the heat dissipation ribs of the present invention in a stepped form to reduce the structural density;

[0021] Figure 5 This is a schematic diagram of the heat dissipation ribs of the present invention in a curved shape to reduce the structural height.

[0022] Figure 6 This is a schematic diagram of the heat dissipation ribs of the present invention in a stepped form to reduce the structural density;

[0023] In the diagram: 1-base plate, 2-cover plate, 3-liquid inlet, 4-liquid outlet, 5-heat dissipation rib, 6-fluid mixing channel, 7-connecting channel, 8-liquid distribution chamber, 9-liquid collection chamber, 10-main channel, 11-reinforcing rib. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 , 2 As shown in Figure 3, in Embodiment 1, a two-phase heat dissipation plate for high-power chip cooling includes a base plate 1 and a cover plate 2. The base plate 1 and the cover plate 2 are sealed together by a sealing ring and bolts or by direct welding, forming a pressure-bearing internal cavity. In this embodiment, the internal cavity is preferably a regular cubic open cavity, which can be achieved by directly machining a cuboid groove on the bottom of the cover plate 2, making the manufacturing of the cover plate 2 very simple and standardized.

[0026] In addition, the cover plate 2 is provided with an inlet 3 and an outlet 4, which are connected to the internal cavity and are used for the inflow and outflow of the cooling working fluid, respectively. Further in this embodiment, both ends of the cover plate 2 are provided with base blocks, and the inlet 3 and outlet 4 are respectively located on the base blocks at both ends. The inlet 3 is connected to a distribution chamber 8, which is located on the base block and connected to the inlet end of the internal cavity, for uniformly distributing the working fluid to each column of flow channels. The outlet 4 is connected to a collection chamber 9, which is located on another base block and connected to the outlet end of the internal cavity, for collecting the working fluid flowing out from each wedge-shaped flow channel 7.

[0027] Within the internal cavity, multiple rows of heat dissipation ribs 5 are arranged parallel to each other along the direction of the working fluid flow from the inlet 3 to the outlet 4 (i.e., the direction of working fluid flow). The heat dissipation ribs 5 can be integrally formed with the base plate 1 by milling or metal additive manufacturing to ensure good heat transfer performance and integrity. The space between two adjacent rows of heat dissipation ribs 5 forms the main flow channel 10 for the longitudinal flow of the working fluid. After entering the internal cavity through the liquid distribution chamber 8, the working fluid is diverted to each main flow channel to absorb heat and then transforms from a single-phase liquid to a gas-liquid two-phase working fluid, which is then collected and discharged through the liquid collection chamber 9.

[0028] In this embodiment, at least a portion of each heat dissipation rib 5 (usually the middle and lower reaches) has a height (along the direction perpendicular to the inner wall of the bottom plate 1) that gradually decreases along the working fluid flow direction. As an optional solution, the height can be gradually reduced in a stepped, linear, or curved manner, thereby utilizing the upper edge of the heat dissipation rib to further disturb the flowing working fluid, improve heat exchange efficiency, and facilitate gas precipitation. Figure 4 , 5 Figures 6 and 7 respectively demonstrate several implementation methods where the height decreases in a stepped, linear, and curved manner. Setting it to a stepped or curved form can further enhance the disturbance effect. Since the top highest point or the top surface of the initial section of the heat dissipation rib 5 is in close contact with the inner wall surface of the cover plate 2, as the rib height decreases, a space is naturally formed between the top of the heat dissipation rib 5 and the inner wall surface of the cover plate 2. This space, located above and connected to the adjacent two columns of main flow channels 10, constitutes the connecting flow channel 7, and the cross-sectional area of ​​the connecting flow channel 7 gradually increases along the flow direction.

[0029] In addition, several through openings are evenly spaced along the length of the heat dissipation rib 5, thus connecting both sides of the heat dissipation rib to form a fluid mixing channel 6. Alternatively, the through openings can be located on the heat dissipation rib itself, or the entire heat dissipation rib can be broken into multiple segments through the through openings. The extension direction of the fluid mixing channel 6 forms a non-zero angle with the working fluid flow direction, preferably perpendicular, and the entire heat dissipation rib is broken for ease of processing. Its function is to allow the working fluid in adjacent main channels 10 to undergo lateral exchange and mixing through the fluid mixing channel 6, thereby generating vortices, enhancing turbulence, facilitating the release of gas after heat absorption, and greatly improving heat exchange efficiency.

[0030] As a further specific implementation, the outer wall surface of the base plate 1 is a flat heat-absorbing mounting surface, which is used to directly contact and adhere to the heat-generating surfaces of high-power chips such as CPUs and GPUs or other electronic components. The projection area of ​​all heat dissipation ribs 5 on the base plate 1 should completely cover the bonding area of ​​the chip to ensure that heat can be efficiently conducted.

[0031] As a further optional implementation, in order to improve structural strength, a reinforcing rib 11 is provided in the middle of the internal cavity along the flow direction of the working fluid, thereby improving the overall structural strength.

[0032] The working process of the two-phase heat dissipation plate in this embodiment is as follows: A single-phase liquid cooling medium (such as deionized water or fluorinated liquid) is pumped in through the inlet 3 and evenly distributed to the inlets of each main channel 10 via the distribution chamber 8. The medium flows within the main channel 10, absorbing heat from the chip transferred from the base plate 1, causing its temperature to rise and begin to boil. During this process, the fluid mixing channel 6 on the heat dissipation rib 5 causes vigorous lateral mixing of the medium, which may have different temperatures and dryness in adjacent main channels 10, disrupting the flow boundary layer, promoting bubble nucleation, detachment, and merging, and significantly enhancing phase change heat transfer. Secondly, as the medium flows downstream and continues to absorb heat and vaporize, its volume continuously expands. As the height of the heat dissipation rib 5 gradually decreases, the space of the connecting channel 7 above it becomes larger and larger, providing a smooth expansion channel for the expanding gas-liquid two-phase medium. This allows the medium to smoothly transition within the connecting channel 7 after flowing out of the main channel 10, effectively avoiding the problems of rapid flow rate increase and excessive pressure drop caused by insufficient flow cross-sectional area. Finally, after sufficient heat exchange and expansion, the two-phase working fluid enters the liquid collection chamber 9 through the connecting channel 7, and is finally discharged from the cold plate through the large-diameter liquid outlet 4, completing the heat dissipation cycle.

[0033] Example 2, based on Example 1, provides a two-phase heat dissipation system, including a two-phase heat dissipation cold plate as described in Example 1, which is integrated into the system as a heat dissipation terminal. The system also includes a pumping device and a condenser, which are connected sequentially by pipes to form a circulation system. The inlet 3 and outlet 4 of the two-phase heat dissipation cold plate are connected to this circulation system. The pumping device drives the working fluid (such as deionized water or fluorinated liquid) to flow in a closed loop: the low-temperature liquid working fluid is pumped into the cold plate to absorb heat and evaporate; the resulting gas-liquid two-phase mixture condenses and releases heat in the condenser, becoming liquid again, thereby achieving circulating heat dissipation.

[0034] This invention achieves regularization, standardization, and flattening of the main structure of the cold plate (especially the internal cavity) while ensuring excellent fluid expansion adaptability and enhanced heat exchange capacity, thus combining the advantages of high performance, high reliability, and low manufacturing cost.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A two-phase heat dissipation plate for high-power chip heat dissipation, comprising a base plate (1), a cover plate (2), a liquid inlet (3), and a liquid outlet (4), wherein the base plate (1) and the cover plate (2) are sealed together to form an internal cavity, and the liquid inlet (3) and the liquid outlet (4) are in communication with the internal cavity, characterized in that: The internal cavity is provided with several rows of heat dissipation ribs (5). The several rows of heat dissipation ribs (5) are arranged in multiple rows at intervals along the working fluid flow direction from the liquid inlet (3) to the liquid outlet (4). A main channel is formed between adjacent heat dissipation ribs (5). The height of at least a portion of each row of heat dissipation ribs (5) gradually decreases along the working fluid flow direction, thereby forming a connecting channel that connects two adjacent main channels and has a gradually increasing cross-sectional area. The heat dissipation ribs (5) are provided with through openings at equal intervals to connect the main channels on both sides. A fluid mixing channel (6) is formed at the through opening. The extension direction of the fluid mixing channel (6) is at a non-zero angle with the flow direction of the working fluid. Both the fluid mixing channel (6) and the connecting channel can be used to disturb the fluid flow in the adjacent main channels.

2. The two-phase heat dissipation plate for high-power chip heat dissipation according to claim 1, characterized in that, The heat dissipation rib (5) includes a straight rib unit. The length extension direction of the straight rib unit is parallel to the working fluid flow direction. The bottom of the straight rib unit is fixedly connected to the inner wall surface of the base plate (1), and the top highest point or the top surface of the highest section is in contact with the inner wall surface of the cover plate (2).

3. The two-phase heat dissipation plate for high-power chip heat dissipation according to claim 2, characterized in that, The height of at least some segments of the heat dissipation ribs (5) gradually decreases in a stepped, straight, or curved manner along the direction of working fluid flow.

4. The two-phase heat dissipation plate for high-power chip heat dissipation according to claim 3, characterized in that, The heat dissipation rib (5) is integrally formed with the base plate (1).

5. The two-phase heat dissipation plate for high-power chip heat dissipation according to claim 1, characterized in that, The internal cavity is a cubic opening at the bottom of the cover plate (2).

6. The two-phase heat dissipation plate for high-power chip heat dissipation according to any one of claims 1 to 5, characterized in that, The diameter of the inlet (3) is smaller than that of the outlet (4) to accommodate the volume change characteristics of the working fluid before and after it is in a single-phase liquid state at the inlet (3) and a two-phase gas-liquid state at the outlet (4).

7. The two-phase heat dissipation plate for high-power chip heat dissipation according to claim 6, characterized in that, The inlet (3) and outlet (4) are both located on the cover plate (2). The inlet (3) is connected to the liquid distribution chamber (8), which is located at the inlet end of the internal cavity. The outlet (4) is connected to the liquid collection chamber (9), which is located at the outlet end of the internal cavity.

8. The two-phase heat dissipation plate for high-power chip heat dissipation according to claim 1 or 7, characterized in that, The outer wall of the base plate (1) is a heat-absorbing mounting surface for bonding with the heat-generating surface of a high-power chip, and the projected area of ​​the heat dissipation rib (5) covers the chip bonding area of ​​the heat-absorbing mounting surface.

9. A two-phase heat dissipation system, characterized in that, It includes a two-phase heat dissipation plate for high-power chip heat dissipation as described in any one of claims 1 to 8, wherein the liquid inlet (3) and the liquid outlet (4) are connected by a pipe, and a pumping device and a condenser are provided on the pipe, wherein the pumping device is used to drive the working fluid to circulate along the pipe.

10. The two-phase heat dissipation system according to claim 9, characterized in that, The working fluid is deionized water or fluorinated liquid.

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