Variable-thickness two-phase cold plate

Abstract

The invention relates to a variable-thickness two-phase cold plate, belongs to the technical field of chip heat dissipation, and solves the technical problems of overhigh local temperature, overlarge overall resistance and the like caused by an existing cold plate structure. The micro-channel two-phase cold plate comprises a bottom plate, a liquid inlet, a liquid outlet, a liquid separation cavity, a liquid collection cavity, a cover body and a fin group, the liquid inlet and the liquid outlet are formed in the bottom plate and / or the cover body; the fin group is arranged in an internal space formed by the bottom plate and the cover body; an internal space defined by the cover body and the bottom plate forms a liquid working medium flowing space of a phase change refrigerant; and fins of the fin group are arranged in a variable-height manner. The height of the flow channel is increased in the flowing direction, the overall heat exchange area of the flow channel is increased, a phase change refrigerant can effectively absorb heat from the bottom plate and the fin set, and the heat exchange capacity of the cold plate is improved; bubble blockage and backflow are reduced, the problems of local evaporation drying, too high temperature and the like of the micro-channel close to the liquid collection cavity are avoided, and friction loss and the overall pressure drop of the two-phase cold plate are reduced.

Description

Technical Field

[0001] This invention relates to the field of chip heat dissipation technology, specifically a two-phase cold plate with variable thickness. Background Technology

[0002] With the continuous advancement of chip technology, the heat flux density per unit area increases with chip power. To ensure the stable operation of chips, the chip temperature must be controlled within a certain range, which places stringent requirements on heat dissipation technology. Traditional air cooling technology cannot meet the heat dissipation needs, while single-phase liquid cooling technology is either limited by the heat transfer performance of the working fluid or cannot avoid the risk of working fluid leakage. More efficient and safer heat dissipation technologies are needed to solve the chip heat dissipation problem.

[0003] Two-phase cold plate liquid cooling technology uses heat to be transferred from the cold plate wall to the liquid, and the liquid changes from a liquid state to a gas state. The latent heat of the liquid phase change makes the two-phase heat exchange performance better and the temperature more uniform. At the same time, the power consumption is lower. Combined with microchannel enhanced heat exchange technology, microchannel two-phase cold plate is an effective solution to solve the heat dissipation needs of high-power chips.

[0004] Currently, as the heat flux density of chips further increases, the heat exchange capacity of microchannel two-phase cold plates needs to be further improved. Existing microchannel two-phase cold plates mostly improve heat exchange efficiency by changing the heat exchange surface structure. However, with the liquid-gas phase change of the working fluid, bubble blockage and backflow are easily formed during flow. At the same time, the uneven distribution of heat source power makes the dryness change of the working fluid flowing through the high heat flux region greater and the volume expansion greater, which can easily lead to problems such as excessively high local temperature of the cold plate and excessive overall resistance. Summary of the Invention

[0005] In view of the above problems, the present invention provides a two-phase cold plate with variable thickness, which solves the technical problems of excessive local temperature and excessive overall resistance caused by the existing cold plate structure, and improves the heat dissipation effect of the two-phase cold plate.

[0006] The present invention provides a two-phase cold plate with variable thickness, including a base plate 1, a liquid inlet 4, a liquid outlet 5, a liquid distribution chamber 7, a liquid collection chamber 8, a cover and a fin assembly 6;

[0007] The liquid inlet 4 and the liquid outlet 5 are provided on the base plate 1 and / or the cover;

[0008] The fin assembly 6 is disposed on the base plate 1 and within the internal space formed by the cover;

[0009] The internal space enclosed by the cover and the base plate 1, and the liquid working medium flow space formed by the fin assembly 6 for the phase change refrigerant; the fin height of the fin assembly 6 gradually increases from the inlet position of the phase change refrigerant to the outlet position.

[0010] Optionally, adjacent fins are spaced apart to form microchannels 9; the liquid working fluid flows in the microchannels 9.

[0011] Optionally, the liquid distribution chamber 7 is located at one end of the phase change refrigerant inlet; the liquid collection chamber 8 is located at one end of the phase change refrigerant outlet.

[0012] Optionally, the height of the top plate 3 is adapted to the shape or height of the fins of the fin assembly 6.

[0013] Optionally, the liquid inlet 4 and the liquid outlet 5 are simultaneously or separately provided on the end plate or the top plate.

[0014] Optionally, the liquid inlet 4 is located near the liquid distribution chamber 7.

[0015] Optionally, the liquid outlet 5 is located near the liquid collection chamber 8.

[0016] Optionally, the liquid inlet 4 and the liquid outlet 5 are respectively located at opposite ends of the cover.

[0017] Optionally, the top plate includes multiple top plate regions; the fin assembly includes multiple fin regions.

[0018] Optionally, the height of multiple fin regions from the liquid inlet 4 to the liquid outlet 5 increases at different slope angles.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] (1) The variable thickness two-phase cold plate of the present invention is configured to vary the height of the microchannel flow channel and the height of the fin assembly along the liquid working fluid flow direction by one or more angles (e.g., increase) according to the change in heating power in different areas of the heat source. Compared with the conventional two-phase cold plate with the same height, the flow channel height of the present invention is increased along the flow direction, which improves the overall heat exchange area of ​​the flow channel, enabling the phase change refrigerant to effectively absorb heat from the base plate and the fin assembly, thereby improving the heat exchange capacity of the cold plate.

[0021] (2) In the microchannel two-phase cold plate of the present invention, when the liquid working fluid flows through the microchannel, it exchanges heat with the bottom plate and fin assembly. At the same time, a phase change occurs, transforming the liquid phase into a gas-liquid two-phase. The closer the microchannel is to the liquid collection chamber, the larger its channel cavity height. The channel fin height can be increased according to the heating power of different areas of the heat source to increase the channel area of ​​the two-phase working fluid after the liquid-gas phase change. This adapts well to the dryness changes of the working fluid in different areas and the increasing volume flow rate of the two-phase fluid, which increases the demand for increased flow area. It also reduces the flow pressure drop of the two-phase working fluid and facilitates the movement of bubbles generated by the phase change from the channel to the downstream liquid collection chamber along the flow direction, reducing bubble blockage and backflow. This avoids problems such as local evaporation and excessive temperature in the microchannel near the liquid collection chamber, reducing friction loss and the overall pressure drop of the two-phase cold plate. Attached Figure Description

[0022] Figure 1 This is an overall structural diagram of Embodiment 1 of the variable thickness two-phase cold plate of the present invention;

[0023] Figure 2 This is an exploded view of Embodiment 1 of the variable thickness two-phase cold plate of the present invention;

[0024] Figure 3 for Figure 1 The variable thickness two-phase cold plate along Figure 1 A cross-sectional view of the structure in the AA direction, indicating the direction of fluid flow;

[0025] Figure 4 This is a schematic diagram of the structure of the base plate in Embodiment 1 of the variable thickness two-phase cold plate of the present invention;

[0026] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0027] Figure 6 This is a front view of the base plate in Embodiment 1 of the variable thickness two-phase cold plate of the present invention;

[0028] Figure 7 This is an overall structural diagram of Embodiment 2 of the variable thickness two-phase cold plate of the present invention;

[0029] Figure 8 This is an exploded view of Embodiment 2 of the variable thickness two-phase cold plate of the present invention;

[0030] Figure 9 for Figure 7 The variable thickness two-phase cold plate along Figure 7 Cross-sectional view of the structure in the BB direction, indicating the direction of fluid flow.

[0031] Figure 10 This is a schematic diagram of the base plate in Embodiment 2 of the variable thickness two-phase cold plate of the present invention;

[0032] Figure 11 This is a front view of the base plate in Embodiment 2 of the variable thickness two-phase cold plate of the present invention;

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Base plate; 2. End plate; 3. Top plate; 4. Liquid inlet; 5. Liquid outlet; 6. Fin assembly; 7. Liquid distribution chamber; 8. Liquid collection chamber; 9. Microchannel flow path. Detailed Implementation

[0035] To better understand the above-described objectives, features, and advantages of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other. Furthermore, the present invention can be implemented in other ways different from those described herein; therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0036] like Figures 1-11 This invention discloses a two-phase cold plate with variable thickness.

[0037] Example 1:

[0038] This invention provides a two-phase cold plate with variable thickness, such as... Figure 1-3 As shown, it includes a base plate 1, a liquid inlet 4, a liquid outlet 5, a cover and a fin assembly 6; the fin assembly 6 is disposed on the base plate 1; the cover is disposed on the base plate 1 and the fin assembly 6; the fins of the fin assembly 6 are set with varying heights; the internal space enclosed by the cover and the base plate 1 forms a liquid working fluid flow space for the phase change refrigerant.

[0039] The enclosure includes a side plate, an end plate 2, and a top plate 3; the end plate 2 is perpendicular to the bottom plate 1 and perpendicular to the flow direction of the phase change refrigerant; the bottom plate 1, the side plate, the end plate 2, and the top plate 3 are sealed together to form a space for the liquid working fluid of the phase change refrigerant to flow.

[0040] The fins of fin group 6 are arranged parallel to the flow direction of the phase change refrigerant; adjacent fins are spaced apart to form microchannel flow channels 9.

[0041] Furthermore, the fin height of the fin assembly 6 gradually increases from the inlet position of the phase change refrigerant to the outlet position; the height of the top plate 3 is adapted to the shape of the fin height of the fin assembly 6.

[0042] Furthermore, the height of the top plate 3 gradually increases from the inlet position of the phase change refrigerant to the outlet position.

[0043] Furthermore, two side plates and two end plates 2 are provided. The two end plates 2 are located at both ends of the cover body, and the two end plates are respectively located between the two end plates 2.

[0044] Furthermore, the liquid inlet 4 and the liquid outlet 5 are respectively located at opposite ends of the cover; respectively located on the end plates at both ends of the cover; the axes of the liquid inlet 4 and the liquid outlet 5 are parallel to the flow direction of the phase change refrigerant.

[0045] In another embodiment, the inlet 4 and the outlet 5 can be located on the same end plate 2, or on different end plates 2, or on the top plate 3, wherein the inlet 4 is close to the liquid distribution chamber 7, and the outlet 5 is close to the liquid collection chamber 8; the diameter of the outlet 4 is less than, greater than or equal to the diameter of the outlet 5.

[0046] In another embodiment, the liquid inlet 4 and the liquid outlet 5 can be located on the same side plate or on different side plates.

[0047] Furthermore, it also includes forming a liquid distribution chamber 7 and a liquid collection chamber 8; the liquid distribution chamber 7 is located at the liquid inlet end of the fin assembly 6, in the liquid working fluid flow space between the liquid inlet end of the fin assembly 6 and the liquid inlet 4; the liquid collection chamber 8 is located at the liquid outlet end of the fin assembly 6, in the coolant flow space between the liquid outlet end of the fin assembly 6 and the liquid outlet 5.

[0048] Furthermore, the side of the end plate 2 facing the bottom plate 1 is the bottom surface of the end plate, and the side of the bottom plate 1 facing the bottom surface of the end plate is the top surface of the bottom plate, and vice versa. The fin assembly 6 is disposed on the top surface of the bottom plate, and the bottom surface of the end plate, the bottom of the fin assembly, and the top surface of the bottom plate are flush. The bottom surface of the bottom plate is in close contact with the heat source, and the projected area of ​​the fin assembly 6 and the microchannel flow channel 9 completely covers the area of ​​the heat source.

[0049] Further, see Figure 3 The height of the microchannel 9 and the height of the fin assembly 6 increase along the liquid working fluid flow direction at a slope angle of θ0 (the angle formed by the top of the fin assembly and the bottom plate plane). The height of the end plate near the liquid outlet is greater than the height of the end plate near the liquid inlet, and the overall height of the cold plate increases from the liquid inlet to the liquid outlet. The tilt angle of the top plate 3 is equal to the slope angle θ0 of the height of the fin assembly 6. Preferably, θ0 = 15°.

[0050] In use, within the microchannel two-phase cold plate, the liquid working medium flows sequentially through the inlet 4, the dispensing chamber 7, the microchannel channel 9, the collecting chamber 8, and the outlet 5 under the action of external driving force. When the liquid working medium flows through the microchannel channel 9, it exchanges heat with the heat absorbed by the bottom plate 1, and at the same time, the liquid working medium undergoes a liquid-gas phase change.

[0051] Furthermore, the base plate 1 and end plate 2 are made of high thermal conductivity materials, such as copper and aluminum.

[0052] In one specific embodiment, the base plate 1 has a length of 55mm, a width of 50mm, and a thickness of 1.5mm, the end plate 2 has a width of 50mm, the end plate height at the liquid inlet end is 7.657mm, and the end plate height at the liquid outlet end is 12.469mm.

[0053] In one specific embodiment, the microchannel flow channel 9 has a length of 37 mm, a fin spacing of 0.4 mm, a single fin width of 0.2 mm in the fin group 6, and a minimum height of 6 mm and a maximum height of 9.237 mm for both the microchannel flow channel 9 and the fin group 6.

[0054] In one specific embodiment, the inlet 4 has a diameter of 4 mm, and the outlet 5 has a diameter of 6.5 mm.

[0055] Example 2:

[0056] like Figure 11 As shown, the height of the microchannel and the height of the fin assembly increase along the liquid working fluid flow direction at two different slope angles; the top plate includes a first top plate region and a second top plate region; the fin assembly includes a first fin region and a second fin region, and the heights of the first fin region and the second fin region increase at different slope angles; the first top plate region is correspondingly arranged with the first fin region and is located near the liquid distribution chamber 7, corresponding to the position of the low heat flux zone; the second top plate region is correspondingly arranged with the second fin region and is located near the liquid collection chamber 8, corresponding to the position of the high heat flux zone.

[0057] See Figure 9 When the heating power on the heat source surface varies in different areas, the height of the microchannel and the height of the fin assembly increase at different slope angles according to the heat flux in different areas, dividing them into low heat flux zones (e.g., heat flux Q1 = 100 W / cm). 2 ) and the high heat flux region (heat flux is Q2 = 200 W / cm²) 2 In the two regions, the height of the microchannel flow path and the height of the fin assembly gradually increase along the liquid working fluid flow direction at the base slope angle θ0 in the low heat flux region, and gradually increase along the liquid working fluid flow direction at the slope angle θ > θ0 in the high heat flux region.

[0058] Furthermore, the relationship between θ and θ0 is: Where k represents the coefficient by which the slope angle changes with heat flow.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A two-phase cold plate with variable thickness, characterized in that, It includes a base plate, liquid inlet, liquid outlet, liquid distribution chamber, liquid collection chamber, cover body, and fin assembly; The liquid inlet and liquid outlet are located on the base plate and / or the cover; The fin assembly is disposed within the internal space formed by the base plate and the cover; The internal space enclosed by the cover and the base plate, and the liquid working medium flow space formed by the fin assembly; the fin height of the fin assembly gradually increases from the inlet position of the phase change refrigerant to the outlet position.

2. The variable thickness two-phase cold plate according to claim 1, characterized in that, Adjacent fins are spaced apart to form microchannels; the liquid working fluid flows in the microchannels.

3. The variable thickness two-phase cold plate according to claim 1 or 2, characterized in that, The liquid separation chamber is located at the inlet end of the phase change refrigerant; the liquid collection chamber is located at the outlet end of the phase change refrigerant.

4. The variable thickness two-phase cold plate according to claim 1 or 2, characterized in that, The height of the top plate is adapted to the shape or height of the fins in the fin assembly.

5. The variable thickness two-phase cold plate according to claim 1, characterized in that, The liquid inlet and liquid outlet are simultaneously or separately located on the end plate or the top plate.

6. The variable thickness two-phase cold plate according to claim 1, characterized in that, The inlet is located near the dispensing chamber.

7. The variable thickness two-phase cold plate according to claim 1, characterized in that, The liquid outlet is located near the liquid collection chamber.

8. The variable thickness two-phase cold plate according to claim 1 or 7, characterized in that, The liquid inlet and liquid outlet are located at opposite ends of the cover.

9. The variable thickness two-phase cold plate according to claim 1 or 7, characterized in that, The top plate includes multiple top plate areas; the fin assembly includes multiple fin areas.

10. The variable thickness two-phase cold plate according to claim 9, characterized in that, The height of multiple finned regions from the liquid inlet to the liquid outlet increases at different slope angles.

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