Two-phase cold plate with three-stage porous heat dissipation and processing method thereof

Abstract

The present application relates to the technical field of semiconductor device heat dissipation, in particular to a two-phase cold plate with three-stage porous heat dissipation and a processing method thereof.The present application discloses a two-phase cold plate with three-stage porous heat dissipation, comprising a substrate, and a micro flow channel is arranged in the substrate.In one aspect, the micro flow channel based on topological optimization is used to regulate flow distribution;in another aspect, micron-level blind holes are processed in the inner bottom of the micro flow channel to improve the surface liquid storage capacity during two-phase boiling and regulate the bubble detachment diameter;in still another aspect, nanometer-level blind holes are processed in the inner bottom and inner wall of the micro flow channel and the micron-level blind holes to increase the gasification core density and strengthen the liquid wicking performance;the three aspects are combined to form three-stage heat dissipation, which can significantly improve the heat dissipation performance of the cold plate.The present application solves the problem of unreasonable design of the existing conventional two-phase cold plate, which is prone to physical damage and affects the heat dissipation performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor device heat dissipation, in particular to a two-phase cold plate with three-stage porous heat dissipation and a processing method thereof. BACKGROUND

[0002] With the continuous increase of electronic equipment power and the increase of integration, the heat generated by the chip is also increasing. If the heat dissipation system is not reasonably designed or the radiator has poor performance, it will cause the chip temperature to be too high, affecting the stability and life of the equipment. The traditional heat dissipation method mainly relies on heat dissipation fans and heat dissipation fins for air cooling. However, this method has certain limitations in heat dissipation effect. With the increase of chip power consumption, more efficient heat dissipation methods such as liquid cooling, heat pipe cooling, etc. are needed. Two-phase cold plate is a kind of high-efficiency cooling device for heat management and heat dissipation. It adopts the working principle of two-phase fluid (liquid and gas) circulation and has a wide application in high-power electronic equipment heat dissipation and heat management.

[0003] The two-phase cold plate is usually composed of multiple small channels, and these channels are filled with working medium (usually liquid or vapor generated by liquid evaporation). When the heat source is applied to the two-phase cold plate, the working medium in the channel realizes heat transfer and absorption through the process of evaporation and condensation.

[0004] Although the two-phase cold plate has many advantages in heat management and heat dissipation, it also has some limitations and improvement space:

[0005] The existing conventional two-phase cold plate is generally designed with flat flow channels, which will inevitably cause the dryness to rise along the channel for the two-phase flow boiling heat transfer process. And with the increase of heat flux, the premature dryout of the downstream often severely limits the heat dissipation limit of the microchannel heat sink. The heat spot caused by local dryout will cause the temperature gradient of the cold plate to increase, resulting in thermal stress, which will cause deformation, fatigue damage and warping of the cold plate material and other physical damage. At the same time, the gas-liquid alternating flow in the microchannel under high heat flux will also cause serious boiling instability; the flow boiling instability in the microchannel is manifested as the regular or irregular oscillation of the wall temperature, inlet and outlet pressure and flow during the boiling process, which eventually triggers the critical heat flux prematurely, thereby deteriorating its heat dissipation performance.

[0006] In summary, the existing conventional two-phase cold plate design is unreasonable and prone to physical damage, affecting its heat dissipation performance. SUMMARY

[0007] Therefore, it is necessary to provide a two-phase cold plate with three-stage porous heat dissipation and a processing method thereof to solve the problem of unreasonable design of the existing conventional two-phase cold plate and the physical damage and the influence on the heat dissipation performance.

[0008] The application adopts the following technical solutions to achieve the above technical effects.

[0009] In a first aspect, the application discloses a two-phase cold plate with three-level porous heat dissipation, comprising a substrate.

[0010] The substrate is provided with a micro channel; one end of the substrate is provided with a liquid inlet, and the other end is provided with a liquid outlet; the liquid inlet is communicated with the liquid outlet through the micro channel.

[0011] The micro channel is a shape-optimized channel obtained by topological optimization for the object to be cooled.

[0012] The inner bottom of the micro channel is uniformly distributed with micrometer-level blind holes.

[0013] The inner bottom and inner wall of the micro channel, and the micrometer-level blind holes are also uniformly distributed with nanometer-level blind holes.

[0014] The nanometer-level blind holes, micrometer-level blind holes and micro channel form three-level heat dissipation.

[0015] The two-phase cold plate with three-level porous heat dissipation is realized according to the method or process of the embodiment of the present application.

[0016] In a second aspect, the application discloses a processing method of a two-phase cold plate with three-level porous heat dissipation, which is used to process the two-phase cold plate with three-level porous heat dissipation disclosed in the first aspect.

[0017] The processing method of the two-phase cold plate with three-level porous heat dissipation comprises the following steps:

[0018] Step one: topological optimization is performed on the flat channel of the conventional two-phase cold plate according to the object to be cooled, to obtain an optimized channel model;

[0019] Step two: the optimized channel model is processed into a three-dimensional entity and used as a raw piece;

[0020] Step three: micrometer-level blind holes are first machined on the inner bottom of the micro channel of the raw piece, and then nanometer-level blind holes are machined on the inner bottom and inner wall of the micro channel and in the micrometer-level blind holes, to obtain a two-level processed piece;

[0021] Step four: the two-level processed piece is used as a bottom plate, and a folded edge is machined on the edge of the bottom plate;

[0022] Step five: a matching top plate is machined according to the specifications of the bottom plate;

[0023] Step six: the top plate and the bottom plate are assembled, and the folded edge and the top plate are sealed, to form the two-phase cold plate with three-level porous heat dissipation.

[0024] The processing method of the two-phase cold plate with three-level porous heat dissipation is implemented according to the method or process of the embodiment of the present disclosure.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The present application develops a two-phase cold plate with three-level porous heat dissipation. On the one hand, the flow distribution is regulated based on the micro-channel of topological optimization. On the other hand, micron-level blind holes are processed in the inner bottom of the micro-channel to improve the surface liquid storage capacity during two-phase boiling and regulate the bubble detachment diameter. In addition, nanometer-level blind holes are processed in the inner bottom and inner wall of the micro-channel and the micron-level blind holes to increase the gasification core density and strengthen the liquid wicking performance. The three-level heat dissipation can significantly improve the heat dissipation performance of the cold plate. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 The structure diagram of the two-phase cold plate with three-level porous heat dissipation provided for embodiment 1 of the present application;

[0029] Figure 2 The top view of the micro-channel in Figure 1

[0030] Figure 3 The top view of the micron-level blind hole in the micro-channel;

[0031] Figure 4 The top view of the nanometer-level blind hole in the micro-channel, which is a circular hole;

[0032] Figure 5 The top view of the nanometer-level blind hole in the micro-channel, which is a regular hexagonal hole;

[0033] Figure 6 The flowchart of the processing method of the two-phase cold plate with three-level porous heat dissipation provided for embodiment 2 of the present application;

[0034] Figure 7 The actual picture of the micron-level and nanometer-level blind holes in the two-phase cold plate with three-level porous heat dissipation provided for embodiment 2 of the present application;

[0035] Figure 8 The performance comparison chart of the two cold plates provided for embodiment 3 of the present application.

[0036] In the drawings, the components represented by each number are listed as follows:​

[0037] 100, bottom plate, 101, folded edge, 102, liquid inlet, 103, liquid outlet, 104, protruding part, 105, recessed part, 200, top plate. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0039] It should be noted that when a component is referred to as "mounted on" another component, it can be directly on the other component or there can be a middle component. When a component is referred to as "disposed on" another component, it can be directly disposed on the other component or there can be a middle component. When a component is referred to as "fixed on" another component, it can be directly fixed on the other component or there can be a middle component.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "including" and "having" are intended to be inclusive and mean that there can be additional

[0041] Embodiment 1

[0042] Referring to Figure 1 which shows the structure of the two-phase cold plate with three-level porous heat dissipation disclosed in Embodiment 1.

[0043] It should be noted that the two-phase cold plate with three-level porous heat dissipation disclosed in Embodiment 1 is intended to cool a to-be-cooled object (such as a chip mentioned in the background art).

[0044] As Figure 1 shown, the two-phase cold plate with three-level porous heat dissipation includes a substrate.

[0045] The substrate is provided with a micro channel. The substrate is provided with a liquid inlet 102 at one end and a liquid outlet 103 at the other end, and the liquid inlet 102 is in communication with the liquid outlet 103 through the micro channel. In this way, the fluid enters from the liquid inlet 102, flows through the micro channel, and is discharged from the liquid outlet 103, and in the process, heat exchange occurs with the substrate, thereby cooling the to-be-cooled object.

[0046] Firstly, considering the subsequent processing mode, the substrate can be divided into a bottom plate 100 and a matched top plate 200.

[0047] The side of the bottom plate 100 facing the top plate 200 is provided with a plurality of protruding parts 104, and the space between the protruding parts 104 is a groove part 105 and forms a micro flow channel; the edge of the bottom plate 100 facing the top plate 200 is further provided with a folded edge 101; the top plate 200 presses the folded edge 101 and the protruding part 104, the protruding part 104 is attached to the top plate 200, and the folded edge 101 is sealed between the top plate 200; the liquid inlet 102 and the liquid outlet 103 are arranged on the folded edge 101.

[0048] Secondly, considering the use effect of the substrate, it is suggested to use a material with a large heat exchange coefficient, such as any one of aluminum, copper, aluminum alloy, and copper alloy.

[0049] It should be emphasized that:

[0050] 1. Referring to Figure 2 , the micro flow channel is a shape-optimized flow channel obtained by topology optimization for the object to be cooled.

[0051] Topology optimization is an iterative optimization method that optimizes the structure to the best design in gradual evolution based on the flow and thermal field of the last iteration. Therefore, for a specific object to be cooled, topology optimization is used to optimize the shape of the flow channel, which can control the flow distribution to a more reasonable state, and to a certain extent, it can strengthen the two-phase boiling heat transfer and improve the premature dryout condition of the downstream.

[0052] In this embodiment 1, the flow channel after topology optimization is as shown in Figure 2 .

[0053] 2. Referring to Figure 3 , the inner bottom of the micro flow channel is uniformly distributed with micron-level blind holes.

[0054] Since topology optimization is a flow channel layout optimization based on single-phase flow, its impact on boiling heat transfer is limited, and it is difficult to solve the problem of local dryout in a targeted manner, therefore, micron-level blind holes are uniformly machined (recommended to use femtosecond laser machining) on the inner bottom of the micro flow channel to further increase the solid-liquid contact area, increase the vapor core density, optimize the bubble detachment diameter and frequency, suppress the expansion of periodic dry spots in the two-phase boiling bubble flow stage, and at the same time, improve the surface liquid storage capacity, suppress the evaporation of the liquid film in the annular flow stage, and avoid the occurrence of local dryout phenomenon.

[0055] In this embodiment 1, as shown in Figure 3As shown, the micron-level blind holes are suggested to be processed into circular holes and arranged in an array: the hole diameter D1 is 30-100 pm, the hole center distance L1 is 150-300 pm, and the hole depth H1 is 170-120 pm; and the more recommended parameters are: the hole diameter D1 is 50 pm, the hole center distance L1 is 200 pm, and the hole depth H1 is 100 pm.

[0056] Of course, the micron-level blind holes can also be processed into other shapes and distribution modes, but should meet the above functional requirements.

[0057] 3. Referring to Figure 4 , the inner bottom and inner wall of the micro channel and the micron-level blind holes are also uniformly distributed with nanometer-level blind holes.

[0058] The inventor found that in addition to the micron-level blind holes improving the liquid storage capacity of the surface, the nanometer-level blind holes can improve the capillary pressure of the surface pores and enhance the surface wicking performance, which is also an effective way to inhibit the evaporation of the two-phase flow micro-liquid film. Therefore, the nanometer-level blind holes are uniformly processed (recommended to use anodic oxidation method) in the inner bottom and inner wall of the micro channel and the micron-level blind holes to improve the wicking performance of the surface, strengthen the ability of liquid transport from the liquid region to the dry region, and inhibit the expansion of the dry region.

[0059] In this embodiment 1:

[0060] 1. As shown in Figure 4 , the nanometer-level blind holes can be processed into circular holes and arranged in a honeycomb shape: the hole diameter D2 is 70-120 nm, the hole center distance L2 is 100-300 nm, and the hole depth H2 is 90-110 nm; and the more recommended parameters are: the hole diameter D2 is 90 nm, the hole center distance L2 is 200 nm, and the hole depth H2 is 100 nm.

[0061] 2. As shown in Figure 5 , the nanometer-level blind holes can also be processed into regular hexagonal holes and arranged in a honeycomb shape: the hole diameter D3 of the circumscribed circle of the regular hexagonal hole is 70-120 nm, the hole center distance L3 is 100-300 nm, and the hole depth H3 is 90-110 nm; and the more recommended parameters are: the hole diameter D3 of the circumscribed circle of the regular hexagonal hole is 90 nm, the hole center distance L3 is 200 nm, and the hole depth H3 is 100 nm.

[0062] Of course, the nanometer-level blind holes can also be processed into other shapes and distribution modes, but should meet the above functional requirements.

[0063] Based on the above structure of the two-phase cold plate, the nanometer-level blind holes, micron-level blind holes, and micro channels in it form a three-level heat dissipation, which can significantly improve the heat dissipation performance of the cold plate.

[0064] Embodiment 2

[0065] This embodiment 2 provides a processing method for a two-phase cold plate with three-stage porous heat dissipation, which is used to process the two-phase cold plate with three-stage porous heat dissipation proposed in embodiment 1.

[0066] See Figure 6 The processing method of a two-phase cold plate with three-stage porous heat dissipation includes the following steps:

[0067] Step 1: Based on the object to be cooled, perform topology optimization on the flat DC channel of the conventional two-phase cold plate to obtain the optimized channel model.

[0068] This step involves applying topology optimization to the design of cold plate microchannels. The specific process is as follows:

[0069] S101, based on CFD simulation, according to the heat distribution of the object to be cooled, with the objective function f as the optimization objective, performs topology optimization on the original straight microchannel of the conventional two-phase cold plate to obtain a two-dimensional topology pattern.

[0070] Heat distribution data of the object to be cooled is obtained using heat capture technology (such as infrared imaging), and a simplified two-dimensional thermal model of the object is constructed to reflect its heat distribution. Then, CFD simulation is performed to adjust the flow channel shape according to the original straight microchannel to verify its effect—with the minimum f as the optimization objective.

[0071] The objective function f is expressed as follows:

[0072] f = a * ΔT + b * T 均 +c*Q+d*ΔF;

[0073] In the formula, ΔT represents the temperature difference on the surface of the cold plate; T 均 ΔF represents the average surface temperature of the cold plate; Q represents the heat exchange capacity of the cold plate; ΔF represents the internal pressure drop of the cold plate.

[0074] a, b, c, and d are weighting coefficients, where a > 0, b > 0, c < 0, and d > 0.

[0075] In other words, f aims to achieve a balance between small surface temperature difference of the cold plate, small average surface temperature of the cold plate, strong heat exchange capacity of the cold plate, and small internal pressure drop of the cold plate. At this time, the flow channel shape corresponds to a two-dimensional topological pattern.

[0076] S102, an optimized flow channel model is constructed based on a two-dimensional topological pattern.

[0077] Since microchannels exist in a three-dimensional entity, it is necessary to convert the two-dimensional topological pattern into three dimensions—that is, to increase the depth to form the channel.

[0078] Step two: The optimized flow channel model is processed into a three-dimensional solid and used as the original part.

[0079] Generally, it is recommended to adopt machine tool processing or 3D printing: the former has lower processing cost, and the latter has higher processing precision, and the selection is made as needed.

[0080] Step three, uniformly distributed micron-level blind holes are processed on the inner bottom of the micro channel of the original piece to obtain a first-level processed piece.

[0081] Step three is recommended to adopt femtosecond laser processing. Femtosecond laser has a very short pulse time of femtosecond (10 -15 s) and a large peak power, which can exceed the damage threshold of most materials, and is very suitable for processing micron-level blind holes.

[0082] In step three, a femtosecond laser processing system is adopted: the femtosecond laser is emitted by a laser, passes through a filter and a focusing lens in a galvanometer system and is focused on the original piece, and the motion trajectory of the original piece is controlled by an optical platform stably moving in x-y-z three-axis directions, so that uniformly distributed micron-level blind holes are processed on the inner bottom of the micro channel.

[0083] Of course, step three can also adopt other ways, but the processed blind holes need to reach micron level.

[0084] Step four, uniformly distributed nanometer-level blind holes are processed on the inner bottom and inner wall of the micro channel and in the micron-level blind holes of the first-level processed piece to obtain a second-level processed piece.

[0085] Step four specifically includes:

[0086] S401, annealing the first-level processed piece to obtain an annealed first-level processed piece;

[0087] In this way, the micron-level blind holes of the annealed first-level processed piece are arranged more regularly.

[0088] S402, electrochemical polishing the annealed first-level processed piece to obtain an electrochemically polished first-level processed piece;

[0089] In this way, through electrochemical polishing, scratches on the surface of the first-level processed piece can be reduced or even eliminated, so that the surface is smoother and more flat.

[0090] S403, first anodizing the electrochemically polished first-level processed piece to obtain a first anodized first-level processed piece;

[0091] In this way, through the first anodizing, the rudimental holes of the nanometer-level blind holes are processed on the inner bottom and inner wall of the micro channel and in the micron-level blind holes, but the rudimental holes are still irregular at this time.

[0092] S404, performing chemical etching treatment on the first-level processed piece after the first anodization to obtain a first-level processed piece after chemical etching;

[0093] In this way, the rough hole processed in S403 is subjected to chemical etching to remove the film to form a shallow pit.

[0094] S405, performing second anodization treatment on the first-level processed piece after chemical etching to obtain a first-level processed piece after second anodization and as a second-level processed piece.

[0095] In this way, in the second anodization treatment, the shallow pit induces an electric field to make the anodization preferentially performed in the shallow pit, so that the nanoscale blind hole is more regular.

[0096] Referring to the above, since two anodization treatments are required, the setting parameters of the two anodization treatments follow the following principles:

[0097] The electrolyte temperature used in the first anodization treatment is lower than the electrolyte temperature used in the second anodization treatment;

[0098] The anodization voltage used in the first anodization treatment is the same as the anodization voltage used in the second anodization treatment;

[0099] The electrolysis time of the first anodization treatment is less than the electrolysis time of the second anodization treatment.

[0100] In the second embodiment, step four is more specifically:

[0101] S401: placing the first-level processed piece into a high-temperature sintering furnace for high-temperature annealing at 400-500°C for 2-4 hours.

[0102] S402: placing the first-level processed piece after annealing into a polishing liquid (a mixed solution of perchloric acid and anhydrous ethanol, the volume ratio of perchloric acid to anhydrous ethanol being 1:4), applying a polishing voltage of 21V, and continuously polishing for 8-10 minutes; the polishing liquid temperature is controlled at 0-5°C.

[0103] S403: placing the first-level processed piece after electrochemical polishing into a 5°C electrolyte (a mixed solution of oxalic acid and anhydrous ethanol, the volume ratio of oxalic acid to anhydrous ethanol being 1:1) as an anode, and using a high-purity graphite sheet as a cathode; applying an anodization voltage of 190V, and continuously anodizing for 8-12 minutes.

[0104] S404: placing the first-level processed piece after the first anodization into a film-removing liquid (a mixed solution of phosphoric acid and chromium trioxide, the volume ratio of phosphoric acid to chromium trioxide being 50mL / L:30g / L), and continuously etching for 80-100 minutes.

[0105] S405: The chemically etched primary workpiece is placed in an electrolyte at 20℃ (using a mixed solution of oxalic acid and anhydrous ethanol, with a volume ratio of oxalic acid to anhydrous ethanol of 1:1) as the anode, and a high-purity graphite sheet is used as the cathode; an anodizing voltage of 190V is applied, and the anodizing time is 60-100min.

[0106] Of course, step four can also be done in other ways, but the blind holes need to be processed to the nanometer scale.

[0107] Step 4: Use the secondary processed part as the base plate 100 and process the folded edge 101 on its edge;

[0108] The matching top plate 200 is manufactured according to the specifications of the base plate 100;

[0109] The top plate 200 and the bottom plate 100 are assembled, and the folded edge 101 is sealed with the top plate 200 to form a two-phase cold plate with three-stage porous heat dissipation.

[0110] Thus, a two-phase cold plate with three-stage porous heat dissipation was fabricated. See the electron microscope images of the micron-sized and nano-sized blind holes contained therein. Figure 7 .

[0111] Example 3

[0112] This embodiment 3 aims to verify the effectiveness of the two-phase cold plate with three-stage porous heat dissipation proposed in embodiment 1: a conventional two-phase cold plate with a flat DC channel design (referred to as conventional MCHS) is compared with the two-phase cold plate with three-stage porous heat dissipation proposed in embodiment 1 (referred to as optimized MCHS), and the effects of the two on different heat flux densities q are examined. w The average pressure drop ΔP and the average heat transfer coefficient h ave For the comparison, see the results. Figure 8 .

[0113] Depend on Figure 8 (a) It can be seen that, compared with the traditional MCHS, the average voltage drop ΔP of the optimized MCHS is significantly reduced; Figure 8 (b) It can be seen that, compared with the traditional MCHS, the average heat transfer coefficient h of the optimized MCHS is higher. ave Significant increase.

[0114] comprehensive Figure 8 It can be seen that the optimized MCHS has lower power consumption in terms of pump power consumption and higher performance in terms of heat exchange capacity, which verifies the effect of the two-phase cold plate with three-stage porous heat dissipation in Example 1.

[0115] Any combination of the technical features in the above embodiments can be made, and for the sake of brevity, not all possible combinations are described above, however, as long as the combination of the technical features does not exist in contradiction, it shall be considered within the scope of the present disclosure.

[0116] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it shall not be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be within the protection scope of the present application. Therefore, the protection scope of the present application patent shall be subject to the appended claims.

Claims

1. A two-phase cold plate with three-level porous heat dissipation, comprising a substrate; a micro-channel is arranged in the substrate; a liquid inlet is arranged at one end of the substrate, and a liquid outlet is arranged at the other end of the substrate; the liquid inlet is communicated with the liquid outlet through the micro-channel; characterized in that, the micro-channel is a shape-optimized channel obtained by topological optimization for a to-be-cooled object; the inner bottom of the micro-channel is uniformly distributed with micron-level blind holes; the micron-level blind holes are used for improving the surface liquid storage capacity during two-phase boiling and regulating the bubble detachment diameter; the inner bottom and inner wall of the micro-channel, and the micron-level blind holes are also uniformly distributed with nanometer-level blind holes; the nanometer-level blind holes are used for increasing the vapor core density and strengthening the liquid wicking performance; the nanometer-level blind holes, the micron-level blind holes, and the micro-channel form three-level heat dissipation. The material of the substrate is any one of aluminum, copper, aluminum alloy, and copper alloy. The micron-level blind holes are circular holes and are arranged in an array. The nanometer-level blind holes are circular holes or regular hexagonal holes and are arranged in a honeycomb shape. The substrate comprises a bottom plate and a matching top plate.

2. The two-phase cold plate with three-stage porous heat dissipation of claim 1, wherein, A plurality of raised portions are arranged on the side of the bottom plate facing the top plate, and the raised portions are arranged between groove portions and form the micro-channel; a folded edge is further arranged on the edge of the bottom plate facing the top plate; the top plate presses the folded edge and the raised portions, the raised portions are attached to the top plate, and the folded edge is sealed with the top plate; the liquid inlet and the liquid outlet are arranged on the folded edge.

3. The two-phase cooling plate with three-stage porous heat dissipation of claim 1, wherein, The method is used for processing the two-phase cold plate with three-level porous heat dissipation. The aperture of the micro-sized blind hole D 1 is 30-100 μm, hole center distance L 1 is 150-300 μm, hole depth H 1 is 170-120 μm.

4. The two-phase cooling plate with three-stage porous heat dissipation of claim 1, wherein, The processing method of the two-phase cold plate with three-level porous heat dissipation comprises the following steps: If the nanoscale blind pore is a circular pore, then its pore diameter... D 2 is 70~120nm, hole center distance L 2 represents 100~300nm, pore depth H 2 is 90~110nm; If the nanoscale blind hole is a regular hexagonal hole, the hole diameter of the circumscribed circle thereof D 3 is 70-120 nm, the hole center distance L 3 is 100-300 nm, the hole depth H 3 is 90-110 nm.

5. The two-phase cooling plate with three-stage porous heat dissipation of any one of claims 1-4, wherein, Step one: topological optimization is performed on the flat channel of a conventional two-phase cold plate according to a to-be-cooled object to obtain an optimized channel model; Step two: the optimized channel model is processed into a three-dimensional entity and used as an original piece; 6. A method of processing a two-phase cold plate with three-stage porous heat dissipation, characterized in that, Step three: micron-level blind holes are uniformly distributed on the inner bottom of the micro-channel of the original piece to obtain a first-level processed piece; Step four: nanometer-level blind holes are uniformly distributed on the inner bottom and inner wall of the micro-channel and in the micron-level blind holes of the first-level processed piece to obtain a second-level processed piece; Step five: the second-level processed piece is used as a bottom plate, and a folded edge is processed on the edge of the bottom plate; A matching top plate is processed according to the specification of the bottom plate; The top plate and the bottom plate are assembled, and the folded edge is sealed with the top plate to form the two-phase cold plate with three-level porous heat dissipation. Step one comprises: S102: constructing an optimized channel model based on a two-dimensional topological pattern. The processing of step three is femtosecond laser processing. Step four comprises:

7. The processing method of a two-phase cold plate with three-stage porous heat dissipation of claim 6, wherein, S401: annealing the first-level processed piece to obtain an annealed first-level processed piece; S101, based on the CFD simulation, according to the heat distribution of the object to be cooled, taking the objective function f The original flat micro-channel of the conventional two-phase cold plate is topologically optimized to obtain a two-dimensional topological pattern, with the minimum being the optimization target. wherein f = ΔT a * ΔT b = T 均 + ΔF c = Q d = ΔF In the formula, ΔT represents the temperature difference on the surface of the cold plate; T 均 represents the average temperature on the surface of the cold plate; Q represents the heat exchange capacity of the cold plate; and ΔF represents the pressure drop in the cold plate. a , b , c , d is a weight coefficient, a > 0, b > 0, c < 0, d > 0; S402: electrochemical polishing the annealed first-level processed piece to obtain an electrochemically polished first-level processed piece; 8. The processing method of a two-phase cold plate with three-stage porous heat dissipation of claim 6, wherein, S403: performing first anodic oxidation on the electrochemically polished first-level processed piece to obtain a first anodically oxidized first-level processed piece; 9. The method of claim 6, wherein the two-phase cooling plate has a three-stage porous heat dissipation. S404: chemically etching the first anodically oxidized first-level processed piece to obtain a chemically etched first-level processed piece; S405: performing second anodic oxidation on the chemically etched first-level processed piece to obtain a second anodically oxidized first-level processed piece, which is used as a second-level processed piece. ​ ​ ​ ​ 10. The method of claim 9, wherein the two-phase cooling plate has a three-stage porous heat dissipation. In the fourth step, the temperature of the electrolyte used in the first anodization process is lower than the temperature of the electrolyte used in the second anodization process; The anodization voltage used in the first anodization process is the same as the anodization voltage used in the second anodization process; The electrolysis time of the first anodization process is less than the electrolysis time of the second anodization process.

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