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

Abstract

The invention relates to the technical field of heat dissipation of semiconductor devices, in particular to a two-phase cold plate with three-stage porous heat dissipation and a processing method of the two-phase cold plate. The invention discloses a two-phase cold plate with three-stage porous heat dissipation, which comprises a substrate, and a micro-channel is arranged in the substrate. On one hand, flow distribution is regulated and controlled based on the micro-channel of topological optimization, and on the other hand, the surface liquid storage capacity during two-phase boiling is improved and the separation diameter of bubbles is regulated and controlled by machining the micron-sized blind holes in the inner bottom of the micro-channel; on the other hand, nanoscale blind holes are formed in the inner bottom and the inner wall of the micro-channel and in the micron-sized blind holes to improve the gasification core density and strengthen the liquid wicking performance; and the three are combined to form three-stage heat dissipation, so that the heat dissipation performance of the cold plate can be remarkably improved. The problems that an existing conventional two-phase cold plate is unreasonable in design, physical damage is prone to occurring, and the heat dissipation performance of the two-phase cold plate is affected are solved.

Description

Technical Field

[0001] The invention relates to the technical field of heat dissipation of semiconductor devices, and in particular to a two-phase cold plate with three-level porous heat dissipation and a processing method thereof. Background Art

[0002] As the power of electronic devices continues to increase and the integration level increases, the heat generated by chips is also increasing. If the heat dissipation system is not designed properly or the radiator performance is poor, the chip temperature will be too high, affecting the stability and life of the equipment. The traditional heat dissipation method mainly relies on cooling fans and heat sinks for air heat dissipation. However, this method has certain limitations in the heat dissipation effect. As the power consumption of chips increases, more efficient heat dissipation methods are needed, such as liquid cooling, heat pipe cooling, etc. The two-phase cold plate is an efficient cooling device for thermal management and heat dissipation. It adopts the working principle of two-phase fluid (liquid and gaseous) circulation and is widely used in heat dissipation and thermal management of high-power electronic equipment.

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

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

[0005] The existing conventional two-phase cold plates are generally designed with flat straight channels. Therefore, for the two-phase flow boiling heat transfer process, its heat dissipation form will inevitably cause the dryness in the flow boiling process to increase along the process. And with the increase of heat flux density, the premature drying up of the downstream often severely limits the heat dissipation limit of the microchannel heat sink. The hot spots caused by local drying up will cause the temperature gradient of the cold plate to increase and generate thermal stress, thereby causing physical damage such as deformation, fatigue damage and warping of the cold plate material. At the same time, the alternating flow of gas-liquid in the microchannel under high heat flux density will also lead to the generation of serious boiling instability; the flow boiling instability in the microchannel is manifested as regular or irregular oscillations of the wall temperature, inlet and outlet pressures and flow rate during the boiling process, which eventually triggers the critical heat flux density prematurely, thereby deteriorating its heat dissipation performance.

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

[0007] Based on this, it is necessary to provide a two-phase cold plate with three-level porous heat dissipation and a processing method thereof to address the problem that the existing conventional two-phase cold plate is designed unreasonable and prone to physical damage, which affects its heat dissipation performance.

[0008] The present invention is implemented by the following technical solutions:

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

[0010] A microchannel 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, and the liquid inlet is connected with the liquid outlet through the microchannel.

[0011] The microchannel is a shape-optimized channel obtained through topology optimization for the object to be cooled;

[0012] The inner bottom of the microchannel is evenly distributed with micrometer-sized blind holes;

[0013] The inner bottom and inner wall of the microchannel, as well as the micron-scale blind holes, are evenly distributed with nano-scale blind holes;

[0014] Nanoscale blind holes, micron-scale blind holes and microchannels form three-level heat dissipation.

[0015] The implementation of the two-phase cold plate with three-level porous heat dissipation is based on the method or process of an embodiment of the present disclosure.

[0016] In a second aspect, the present invention discloses a method for processing 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 method for manufacturing a two-phase cold plate with three-level porous heat dissipation comprises the following steps:

[0018] Step 1: topologically optimize the flat flow channel of the conventional two-phase cold plate according to the object to be cooled, and obtain an optimized flow channel model;

[0019] Step 2: Processing the optimized flow channel model into a three-dimensional entity as an original part;

[0020] Step 3, firstly, processing the original part into micron-scale blind holes on the inner bottom of the microfluidic channel, and then processing nano-scale blind holes on the inner bottom and inner wall of the microfluidic channel and in the micron-scale blind holes to obtain a secondary processed part;

[0021] Step 4, using the secondary processed part as the base plate and processing the folded edge on the edge thereof;

[0022] Step 5: Process the matching top plate according to the specifications of the bottom plate;

[0023] Step six, assemble the top plate and the bottom plate, and seal the folded edge and the top plate to form a two-phase cold plate with three-level porous heat dissipation.

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

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

[0026] The present invention develops a two-phase cold plate with three-level porous heat dissipation. On the one hand, the flow distribution is regulated based on the topologically optimized microchannel. On the other hand, micron-level blind holes are machined on the inner bottom of the microchannel to improve the surface liquid storage capacity during two-phase boiling and regulate the bubble detachment diameter. On the other hand, nanometer-level blind holes are machined on the inner bottom and inner wall of the microchannel and in the micron-level blind holes to increase the gasification core density and enhance the liquid wicking performance. The combination of the three forms three-level heat dissipation, which can significantly improve the heat dissipation performance of the cold plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A structural diagram of a two-phase cold plate with three-level porous heat dissipation provided in Example 1 of the present invention;

[0029] Figure 2 for Figure 1 A top view of the microfluidic channel in FIG.

[0030] Figure 3 A top view of a micrometer-scale blind hole in a microfluidic channel;

[0031] Figure 4 It is a top view when the nanoscale blind hole in the microfluidic channel is a circular hole;

[0032] Figure 5 It is a top view when the nanoscale blind hole in the microfluidic channel is a regular hexagonal hole;

[0033] Figure 6 A flow chart of a method for processing a two-phase cold plate with three-level porous heat dissipation provided in Example 2 of the present invention;

[0034] Figure 7 A physical picture of two types of blind holes, micron-scale and nanometer-scale, in a two-phase cold plate with three-level porous heat dissipation provided in Example 2 of the present invention;

[0035] Figure 8 This is a performance comparison chart of two cold plates provided in Example 3 of the present invention.

[0036] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0037] 100, bottom plate, 101, folded edge, 102, liquid inlet, 103, liquid outlet, 104, raised portion, 105, groove portion, 200, top plate. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0041] Example 1

[0042] See also Figure 1 , which shows the structural diagram of the two-phase cold plate with three-level porous heat dissipation disclosed in Example 1.

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

[0044] like Figure 1 As shown, a two-phase cold plate with three-stage porous heat dissipation includes a base plate.

[0045] A microchannel is provided in the substrate. A liquid inlet 102 is provided at one end of the substrate and a liquid outlet 103 is provided at the other end. The liquid inlet 102 is connected to the liquid outlet 103 through the microchannel. In this way, the fluid enters from the liquid inlet 102, flows through the microchannel, and is discharged from the liquid outlet 103. In this process, heat is exchanged with the substrate, thereby cooling the object to be cooled.

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

[0047] A plurality of raised portions 104 are provided on one side of the bottom plate 100 facing the top plate 200, and groove portions 105 are provided between the raised portions 104 to form a microchannel; a folded edge 101 is also provided on the edge of the bottom plate 100 facing the top plate 200; the top plate 200 presses the folded edge 101 and the raised portions 104, the raised portions 104 fit the top plate 200, and the folded edge 101 and the top plate 200 are sealed; a liquid inlet 102 and a liquid outlet 103 are provided on the folded edge 101.

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

[0049] It is important to emphasize that:

[0050] 1. See Figure 2 The microchannel is a shape-optimized channel obtained through 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 a gradual evolution based on the flow and thermal field of the previous iteration. Then, for the specific object to be cooled, the topology optimization is used to optimize the flow channel shape, which can adjust the flow distribution to a more reasonable state, and to a certain extent strengthen the two-phase boiling heat transfer and improve the situation of premature drying downstream.

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

[0053] 2. See Figure 3 ,The inner bottom of the microchannel is evenly distributed with micron-sized blind holes.

[0054] Since topology optimization is based on the optimization of flow channel layout for single-phase flow and has limited influence on boiling heat transfer, and it is difficult to solve the problem of local drying up in a targeted manner, micron-level blind holes are uniformly processed (femtosecond laser processing is recommended) on the inner bottom of the microchannel to further increase the solid-liquid contact area, increase the gasification core density, optimize the bubble detachment diameter and frequency, and inhibit the expansion of periodic dry spots in the two-phase boiling bubble flow stage. At the same time, the surface liquid storage capacity is improved, the evaporation of the liquid film in the annular flow stage is inhibited, and the occurrence of local drying up is avoided.

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

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

[0057] 3. See Figure 4 , nanoscale blind holes are evenly distributed on the inner bottom and inner wall of the microchannel, as well as in the micron-scale blind holes.

[0058] The inventors found that in addition to micron-scale blind holes improving the surface liquid storage capacity, nano-scale blind holes can be used to increase the capillary pressure of surface pores and enhance the surface wicking performance, which is also an effective way to inhibit the evaporation of two-phase flow micro-liquid membranes. Therefore, nano-scale blind holes are uniformly processed (anodization is recommended) on the inner bottom and inner wall of the microchannel and in the micron-scale blind holes to improve the surface wicking performance, strengthen the ability of liquid to be transported from the liquid area to the dry area, and inhibit the expansion of the dry area.

[0059] In this embodiment 1:

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

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

[0062] Of course, nanoscale blind holes can also be processed into other shapes and distributions, but they should meet the above functional requirements.

[0063] Based on the two-phase cold plate of the above structure, the nanoscale blind holes, micrometer-scale blind holes and microchannels therein form three-level heat dissipation, which can significantly improve the heat dissipation performance of the cold plate.

[0064] Example 2

[0065] This embodiment 2 provides a method for processing 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 proposed in embodiment 1.

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

[0067] Step 1: Topologically optimize the flow channel of a conventional two-phase cold plate according to the object to be cooled to obtain an optimized flow channel model.

[0068] This step is to apply topology optimization to the cold plate microchannel design. The specific process is as follows:

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

[0070] The heat distribution data of the object to be cooled is obtained by using heat capture technology (such as infrared photography), and a simplified two-dimensional thermal model of the object to be cooled is constructed to reflect its heat distribution. Then, the CFD simulation will adjust different flow channel shapes based on the original straight microchannel to verify its effect - with the minimum f as the optimization goal.

[0071] Among them, the expression of the objective function f is:

[0072] f=a*ΔT+b*T 均 +c*Q+d*ΔF;

[0073] Where ΔT represents the surface temperature difference of the cold plate; T 均 represents the average surface temperature of the cold plate; Q represents the heat exchange capacity of the cold plate; ΔF represents the pressure drop inside the cold plate;

[0074] a, b, c, d are weight coefficients, a>0, b>0, c<0, d>0.

[0075] In other words, f aims to obtain a situation in which the temperature difference on the cold plate surface is small, the average temperature on the cold plate surface is small, the heat exchange capacity of the cold plate is strong, and the pressure drop inside the cold plate is small. At this time, the shape of the flow channel corresponds to the two-dimensional topological pattern.

[0076] S102, constructing an optimized flow channel model based on the two-dimensional topological pattern.

[0077] Since microfluidics exist in three-dimensional entities, the two-dimensional topological pattern needs to be converted into three dimensions - that is, the depth needs to be increased to form the flow channel.

[0078] Step 2: Process the optimized flow channel model into a three-dimensional entity as a raw part.

[0079] Generally, it is recommended to use machine tool processing or 3D printing: the former has lower processing costs, and the latter has higher processing precision. You can choose according to your needs.

[0080] Step three, processing the original part into uniformly distributed micron-sized blind holes on the inner bottom of the microfluidic channel to obtain a primary processed part.

[0081] Step 3 is recommended to use femtosecond laser treatment. -15 s) and has 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 used: the femtosecond laser is emitted by the laser, focused on the original part through the filter and focusing lens in the galvanometer system, and the movement trajectory of the original part is controlled by an optical platform that can stably move in the xyz three-axis directions, thereby processing evenly distributed micron-level blind holes on the inner bottom of the microchannel.

[0083] Of course, step three may also be performed in other ways, but the blind hole to be processed needs to reach the micron level.

[0084] Step 4: Process the primary processed part to form uniformly distributed nanometer-scale blind holes on the inner bottom and inner wall of the microchannel and in the micrometer-scale blind holes to obtain a secondary processed part.

[0085] Step 4 specifically includes:

[0086] S401, performing annealing treatment on the primary workpiece to obtain the annealed primary workpiece;

[0087] In this way, the primary processed part after annealing will have a more regular arrangement of micron-sized blind holes.

[0088] S402, performing electrochemical polishing on the annealed primary workpiece to obtain an electrochemically polished primary workpiece;

[0089] In this way, electrochemical polishing can reduce or even eliminate scratches on the surface of the primary workpiece, making its surface smoother and flatter.

[0090] S403, performing a first anodizing treatment on the primary processed part after electrochemical polishing to obtain a primary processed part after first anodizing;

[0091] In this way, through the first anodizing treatment, the prototype holes of nanometer-scale blind holes are processed in the inner bottom and inner wall of the microchannel and in the micrometer-scale blind holes, but the prototype holes are still irregular at this time.

[0092] S404, chemically corroding the primary processed part after the first anodization to obtain a chemically corroded primary processed part;

[0093] In this way, the prototype hole processed by S403 is chemically etched to remove the film to form a shallow pit.

[0094] S405, performing a second anodizing treatment on the primary processed part after chemical etching to obtain the primary processed part after the second anodizing as the secondary processed part.

[0095] Thus, in the second anodizing treatment, the shallow pits will induce an electric field so that anodizing will be performed preferentially in the shallow pits, thereby making the nanoscale blind holes more regular.

[0096] As mentioned above, since two anodizing treatments are required, the setting parameters of the two follow the following principles:

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

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

[0099] The electrolysis time of the first anodizing treatment is shorter than that of the second anodizing treatment.

[0100] In this embodiment 2, step 4 is more specifically:

[0101] S401: placing the primary processed part into a high temperature sintering furnace and performing high temperature annealing at 400°C to 500°C for 2 to 4 hours.

[0102] S402: Place the annealed primary workpiece into a polishing liquid (a mixture of perchloric acid and anhydrous ethanol, with a volume ratio of perchloric acid to anhydrous ethanol of 1:4), apply a polishing voltage of 21V, and continue polishing for 8 to 10 minutes; the temperature of the polishing liquid is controlled at 0 to 5°C.

[0103] S403: The primary workpiece after electrochemical polishing is placed in a 5°C electrolyte (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 as the cathode; an anodic oxidation voltage of 190V is applied, and the continuous anodic oxidation time is 8 to 12 minutes.

[0104] S404: Put the primary processed parts after the first anodization into the membrane liquid (a mixed solution of phosphoric acid and chromium trioxide is used, and the volume ratio of phosphoric acid and chromium trioxide is 50mL / L:30g / L), and the chemical corrosion time is continued for 80 to 100 minutes.

[0105] S405: Place the primary processed part after chemical etching into a 20°C electrolyte (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 as the cathode; apply an anodic oxidation voltage of 190V, and continue the anodic oxidation time for 60 to 100 minutes.

[0106] Of course, step 4 may also be performed in other ways, but the blind hole to be processed needs to reach the nanometer level.

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

[0108] A matching top plate 200 is processed according to the specifications of the bottom plate 100;

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

[0110] At this point, a two-phase cold plate with three-level porous heat dissipation has been processed. The electron microscope images of the micron-scale blind holes and nano-scale blind holes contained in it can be seen in Figure 7 .

[0111] Example 3

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

[0113] Depend on Figure 8 (a) It can be seen that compared with the traditional MCHS, the average pressure 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 ave Significant increase.

[0114] comprehensive Figure 8 It can be seen that the optimized MCHS has lower 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 of Example 1.

[0115] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A two-phase cold plate with three-level porous heat dissipation, comprising a substrate; a microchannel 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, and the liquid inlet is connected to the liquid outlet through the microchannel; characterized in that: The microchannel is a shape-optimized channel obtained through topology optimization for the object to be cooled; The inner bottom of the microchannel is uniformly distributed with micrometer-sized blind holes; The inner bottom and inner wall of the microchannel, as well as the micron-scale blind holes, are evenly distributed with nano-scale blind holes; The nanometer-scale blind holes, micrometer-scale blind holes and microchannels form three levels of heat dissipation.

2. A two-phase cold plate with three-stage porous heat dissipation according to claim 1, characterized in that: The material of the substrate is any one of aluminum, copper, aluminum alloy and copper alloy.

3. A two-phase cold plate with three-stage porous heat dissipation according to claim 1, characterized in that: Micron-scale blind holes are circular holes and are distributed in an array; The aperture D1 of the micron-scale blind hole is 30-100 μm, the hole center distance L1 is 150-300 μm, and the hole depth H1 is 170-120 μm.

4. A two-phase cold plate with three-stage porous heat dissipation according to claim 1, characterized in that: Nanoscale blind holes are circular holes or regular hexagonal holes and are distributed in a honeycomb pattern; Wherein, if the nanoscale blind hole is a circular hole, its 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; If the nanoscale blind hole is a regular hexagonal hole, the diameter D3 of the circumscribed circle thereof is 70 to 120 nm, the hole center distance L3 is 100 to 300 nm, and the hole depth H3 is 90 to 110 nm.

5. A two-phase cold plate with three-stage porous heat dissipation according to any one of claims 1 to 4, characterized in that: The substrate comprises: a bottom plate and a matching top plate; A plurality of protrusions are arranged on one side of the bottom plate facing the top plate, and grooves are arranged between the protrusions to form microchannels; a folded edge is also arranged on the edge of the bottom plate facing the top plate; the top plate presses the folded edge and the protrusions, the protrusions fit the top plate, and the folded edge and the top plate are sealed; the liquid inlet and the liquid outlet are arranged on the folded edge.

6. A method for processing a two-phase cold plate with three-level porous heat dissipation, characterized in that: It is used to process the two-phase cold plate with three-level porous heat dissipation as claimed in claim 5; The processing method of the two-phase cold plate with three-level porous heat dissipation comprises the following steps: Step 1: topologically optimize the flat flow channel of the conventional two-phase cold plate according to the object to be cooled, and obtain an optimized flow channel model; Step 2: Processing the optimized flow channel model into a three-dimensional entity as an original part; Step 3, processing the original part into uniformly distributed micron-scale blind holes on the inner bottom of the microchannel to obtain a primary processed part; Step 4, machining the primary workpiece into uniformly distributed nanometer-scale blind holes on the inner bottom and inner wall of the microchannel and in the micrometer-scale blind holes to obtain a secondary workpiece; Step 5, using the secondary processed part as the base plate and processing the folded edge on the edge thereof; Process the matching top plate according to the specifications of the bottom plate; The top plate and the bottom plate are assembled, and the folded edge and the top plate are sealed to form a two-phase cold plate with three-level porous heat dissipation.

7. A method for processing a two-phase cold plate with three-level porous heat dissipation according to claim 6, characterized in that: Step one includes: S101, based on CFD simulation, according to the heat distribution of the object to be cooled, taking the minimum objective function f as the optimization goal, topologically optimizing the original straight microchannel of the conventional two-phase cold plate to obtain a two-dimensional topological pattern; where f = a*ΔT + b*T 均 + c*Q + d*ΔF; Where ΔT represents the surface temperature difference of the cold plate; T 均 represents the average surface temperature of the cold plate; Q represents the heat exchange capacity of the cold plate; ΔF represents the pressure drop inside the cold plate; a, b, c, d are weight coefficients, a>0, b>0, c<0, d>0; S102, constructing an optimized flow channel model based on the two-dimensional topological pattern.

8. The method for processing a two-phase cold plate with three-level porous heat dissipation according to claim 6, characterized in that: The processing in step three is femtosecond laser processing.

9. The method for processing a two-phase cold plate with three-level porous heat dissipation according to claim 6, characterized in that: Step 4 includes: S401, performing annealing treatment on the primary workpiece to obtain the annealed primary workpiece; S402, performing electrochemical polishing on the annealed primary workpiece to obtain an electrochemically polished primary workpiece; S403, performing a first anodizing treatment on the primary processed part after electrochemical polishing to obtain a primary processed part after first anodizing; S404, chemically corroding the primary processed part after the first anodization to obtain a chemically corroded primary processed part; S405, performing a second anodizing treatment on the primary processed part after chemical etching to obtain the primary processed part after the second anodizing as the secondary processed part.

10. A method for processing a two-phase cold plate with three-level porous heat dissipation according to claim 9, characterized in that: In step 4, the temperature of the electrolyte used in the first anodizing treatment is lower than the temperature of the electrolyte used in the second anodizing treatment; The anodizing voltage used in the first anodizing treatment is the same as the anodizing voltage used in the second anodizing treatment; The electrolysis time of the first anodizing treatment is shorter than that of the second anodizing treatment.

Images