A surface of a hybrid micro / nano structure matrix array and its preparation and testing methods

Abstract

The present invention discloses a hybrid micro / nano-structured matrix array surface and its preparation and testing methods, belonging to the technical field of multiphase flow and heat transfer. The copper surface is divided into a matrix grid array, and the matrix grid array includes micro-ribbed columns serving as nucleate boiling activation regions and micro-channels serving as liquid siphon replenishment regions. Microporous arrays are arranged on the surfaces of the micro-ribbed columns, and the micro-channels are arranged at the gaps between the micro-ribbed columns. The micro-ribbed columns are made of pure copper, and the micro-channels are filled with copper foam grids. A hybrid micro / nano-structured matrix array surface for enhancing boiling heat transfer prepared by the present invention aims to combine the unique advantages of different surface structures, efficiently utilize the solid-liquid heat transfer interface, and achieve an overall improvement in boiling heat transfer performance. This hybrid matrix array surface is convenient to prepare, has a low manufacturing cost, and has a strong structure, and will show great potential in future application scenarios with high heat flux density heat dissipation requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of multiphase flow and heat transfer, and particularly relates to a hybrid micro / nano structure matrix array surface and its preparation and testing methods. Background Art

[0002] With the progress of the microelectronics technology field in recent decades, electronic devices have shown iterative leaps in performance and efficiency. Inevitably, this is accompanied by a continuous increase in the heat dissipation density. The continuous increase in the heat flux density of electronic components and the gradual reduction in the size of device components have posed more stringent requirements and technical challenges to cooling technologies. How to solve the problems of reduced efficiency and shortened lifespan caused by overheating of high-power components has always been an important issue of concern. Traditional air cooling and single-phase liquid cooling methods are restricted by the problems of low heat transfer coefficient and poor heat transfer performance. The two-phase flow cooling method with greater performance potential has gradually attracted more attention. Among them, pool boiling / immersion cooling technology has many practical advantages such as high heat transfer coefficient, stable hydraulic and thermodynamic properties, good direct contact temperature control effect, and the flexibility to choose active or passive methods according to actual needs.

[0003] However, for decades, there have been three major problems in pool boiling heat transfer, including: the start-up (ONB) hysteresis of nucleate boiling, the low two-phase heat transfer coefficient (HTC), and the low critical heat flux density (CHF). There are many methods proposed by researchers in this technical field to enhance the surface structure of boiling heat transfer performance. However, the vast majority of methods use a single micro-structure design or a combination of two micro-structures. Therefore, a single structure form usually only brings significant advantages in one or two aspects of boiling heat transfer characteristics such as ONB, HTC, or CHF, and it is often difficult to comprehensively improve the comprehensive performance of boiling heat transfer. Summary of the Invention

[0004] The purpose of the present invention is to provide a hybrid micro / nano structure matrix array surface and its preparation and testing methods, aiming to combine the unique advantages of different surface structures, efficiently utilize the solid-liquid heat transfer interface, and achieve a comprehensive improvement in boiling heat transfer performance. This hybrid matrix array surface is easy to prepare, has a low manufacturing cost, and a strong structure, and will show great potential in future application scenarios with high heat flux density heat dissipation requirements.

[0005] To achieve the above purpose, the present invention provides a hybrid micro / nano structure matrix array surface. The copper surface is divided into a matrix grid array. The matrix grid array includes micro-rib columns as nucleate boiling activation regions and micro-channels as liquid siphon replenishment regions. The surface of the micro-rib columns is arranged with a micropore array as boiling activation cores, and the micro-channels are arranged at the gaps between the micro-rib columns.

[0006] Preferably, the micro-ribs are made of pure copper, the micro-channels are filled with copper foam grids, and the height of the copper foam grids is not higher than the height of the micro-ribs.

[0007] Preferably, the cavity radius of the micropore array is 40 um to 100 um.

[0008] Preferably, a super-hydrophilic CuO nano-coating structure is provided on the surface of the copper foam grid.

[0009] The present invention also provides a method for preparing a hybrid micro / nano structure matrix array surface, comprising the following steps:

[0010] S1, dividing a 10 mm × 10 mm copper surface into a matrix grid array to form micro-ribs and micro-channels with height differences;

[0011] S2, using a laser cutting machine to cut the pure copper foam into a copper foam grid that matches the size of the microchannel, cleaning it with an ultrasonic water bath device, and then performing an oxidation treatment to form a super-hydrophilic CuO nano-coating structure on the surface of the copper foam grid, and embedding the copper foam grid into the microchannel;

[0012] S3. Calculate the preferred diameter range of the pore size of the micropore array for nucleate boiling based on the boiling phase change activation theory; then design the planar layout based on the specific size of the selected pores; finally, according to the design drawing, use laser etching to drill the cavity array on the surface of the top of the micro-rib column.

[0013] Preferably, in step S2, the cleaning solution in the ultrasonic water bath device is dilute hydrochloric acid, the oxidation treatment solution is a mixed solution of sodium hydroxide and ammonium persulfate, and the oxidation treatment condition is heating in a 70° C. water bath for 30 min.

[0014] The present invention also provides a method for testing the surface of a hybrid micro / nano structure matrix array, which uses a pool boiling experimental device to continuously provide heat to a test sample on the surface of a hybrid micro / nano structure matrix array to deduce the surface temperature of the test sample.

[0015] Preferably, the pool boiling experimental device includes: a boiling water pool cavity, a bottom heating module, a heat transfer surface performance test part, a liquid temperature control unit, a power supply regulator, a data acquisition and processing system, a computer, a high-speed camera and a high-illuminance lamp. The heat transfer surface performance test part is arranged between the boiling water pool cavity and the bottom heating module, the boiling water pool cavity is electrically connected to the liquid temperature control unit, the heat transfer surface performance test part and the liquid temperature control unit are connected to the data acquisition and processing system, and the computer controls the data acquisition and processing system, the high-speed camera and the high-illuminance lamp.

[0016] Preferably, a serpentine condenser and a cover plate for maintaining the water level are provided at the upper part of the boiling water tank cavity, and an auxiliary heating rod electrically connected to the liquid temperature control unit is arranged inside the boiling water tank cavity. The test sample is hermetically fixed to the bottom partition of the boiling water tank cavity with high-temperature resistant glue.

[0017] The bottom heating module includes copper columns and a heating copper base arranged below the copper columns. Three T-type thermocouples are inserted into the copper columns, and an insert type heating rod is arranged below the heating copper base.

[0018] The test sample is arranged on the copper columns of the bottom heating module. The contact surface between the copper columns and the test sample uses a high thermal conductivity gallium-based liquid alloy. The gap between the insert type heating rod and the heating copper base is filled with silicone grease with good thermal conductivity. The outside of the heating copper base is wrapped with mica and alumina high-temperature resistant ceramics.

[0019] Preferably, a T-type thermocouple for detecting the temperature of the test sample is inserted into the test sample. Three T-type thermocouples are longitudinally inserted into the copper columns. The T-type thermocouples are connected to the heat transfer surface performance test part, and the surface temperature of the test sample is calculated based on the temperatures of the four T-type thermocouples.

[0020] Therefore, the present invention adopts the above-mentioned hybrid micro / nano structure matrix array surface and its preparation and testing method, and its beneficial effects are as follows:

[0021] 1. By constructing a hybrid surface, the present invention realizes nucleate boiling when the wall superheat is only 2°C. Compared with the ordinary copper surface, the increment of the two-phase heat transfer coefficient HTC is as high as 85%, and the increment of the critical heat flux density CHF is significantly increased by 226% (332.4 W / cm 2 ).

[0022] 2. The present invention provides a new idea for preparing a hybrid micro / nano structure matrix array surface on the material surface to improve its boiling heat transfer performance. It is not limited to copper materials, and other materials with high thermal conductivity such as aluminum materials can be used, and even semiconductor silicon Si can also be applied.

[0023] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a conceptual diagram of the hybrid micro / nano structure matrix array surface proposed by the present invention;

[0025] Figure 2 is a schematic diagram of the partition design and the planar layout of different functional areas of the hybrid micro / nano structure matrix array surface in Embodiments 1-3 of the present invention;

[0026] Figure 3 Calculation diagram of the laser hole cavity size on the top surface of the micro-ribbed column of the present invention;

[0027] Figure 4 Plan layout design diagram of the micro-hole array of the present invention;

[0028] Figure 5 Electron microscopic characterization diagram of the laser machined micro-hole array of the present invention;

[0029] Figure 6 Fabrication process of the foam grid with superhydrophilic CuO nano-coating structure;

[0030] Figure 7 Electron microscope characterization diagram of the copper foam grid with superhydrophilic CuO nano-coating structure;

[0031] Figure 8 Structural schematic diagram of three embodiments of the present invention;

[0032] Figure 9 Structural schematic diagram of the pool boiling experimental device of the present invention;

[0033] Figure 10 Placement schematic diagram of the test sample in the pool boiling experimental device of the present invention;

[0034] Figure 11 Comparison diagram of the boiling heat transfer performance of three embodiments of the present invention and the comparative example.

[0035] Reference numerals:

[0036] 1. Boiling water tank cavity; 11. Cover plate; 12. Vent hole; 13. Serpentine condenser; 14. Observation glass; 15. Auxiliary heating rod; 2. Test sample; 3. Bottom heating module; 31. Copper column; 32. Heating copper substrate; 33. Insertion type heating rod; 34. Mica stone; 35. Alumina high temperature resistant ceramic; 36. High thermal conductivity gallium oxide based liquid alloy; 37. Stainless steel support layer; 4. Heat transfer surface performance test part; 41. T-type thermocouple; 5. Liquid temperature control unit; 6. Data acquisition and processing system; 7. Computer; 8. High illuminator; 9. High speed camera. Detailed implementation manners

[0037] The technical solutions of the present invention will be further described below with reference to the drawings and embodiments.

[0038] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs.

[0039] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only one independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. These other embodiments are also covered by the protection scope of the present invention.

[0040] The present invention provides a hybrid micro / nano-structured matrix array surface, which divides a 10 mm × 10 mm copper surface into a matrix grid array. The matrix grid array includes micro-ribbed columns serving as nucleate boiling activation regions and micro-channels serving as liquid siphon replenishment regions. Microporous arrays serving as boiling activation cores are uniformly arranged on the surface of the micro-ribbed columns to accelerate the initiation of nucleate boiling and achieve efficient phase change heat transfer at the solid-liquid interface; the micro-channels are arranged at the gaps between the micro-ribbed columns. The micro-channels are embedded with copper foam grids with a super-hydrophilic CuO nano-coating structure, which is responsible for the rapid siphoning, storage of liquid, and resistance to wall dry-out phenomena caused by high heat flux conditions. The height of the copper foam grid is not higher than the height of the micro-ribbed column. The pore cavity radius of the microporous array is 40 μm to 100 μm.

[0041] The working principle of this hybrid micro / nano-structured matrix array surface is as shown in the attached Figure 1 description. In the figure, A shows the boiling phase change behavior of the hybrid micro / nano-structured matrix array surface proposed by the present invention under normal working conditions. The hybrid surface with functional partitions can, on the one hand, promote the generation and growth of boiling bubbles, have high liquid-vapor phase change conversion efficiency and a relatively high heat transfer coefficient (HTC); on the other hand, it can significantly enhance the siphon effect of the liquid, keep the bottom of the copper-based surface wet, and prevent dry-out or burnout phenomena from occurring at extremely high heat dissipation densities, thereby improving the performance limit value (CHF) of boiling phase change.

[0042] In the figure, B shows that at the onset of nucleate boiling (ONB), the artificial laser cavities at the top of the copper micro-ribbed columns can promote and accelerate the generation of bubbles, reduce the minimum starting energy requirement for nucleate boiling phase change, and greatly promote nucleate boiling.

[0043] In the figure, C shows that in the fully developed boiling (FDB) stage, as the heat flux density gradually increases, the bubbles merge with each other to form larger-volume bubbles. At the same time, the copper foam grid with a CuO nano-coating at the bottom of the copper micro-ribbed columns can continuously siphon and store liquid, maintain good wettability of the solid-liquid interface for a long time, and maintain a stable boiling phase change process.

[0044] In the figure, D shows that when approaching the critical heat flux (CHF) condition, huge volumes of bubbles are formed and cover the solid surface. At this time, the solid surface has lost the replenishment of the surrounding liquid, but can still be maintained in a wetted state for a certain period of time by the liquid stored in the copper foam grid of the CuO nano - coating at the bottom of the copper micro - rib columns, so as to keep the boiling phase change proceeding normally. Finally, the hybrid micro / nano - structured surface can obtain an ultra - high heat dissipation flux without being burned out.

[0045] A preparation method for a hybrid micro / nano - structured matrix array surface, comprising the following steps:

[0046] S1. Divide a 10mm×10mm copper surface into a matrix grid array to form micro - rib columns and micro - channels with a height difference;

[0047] S2. Use a laser cutting machine to cut pure copper foam into copper foam grids matching the size of the micro - channels. After cleaning with an ultrasonic water bath device, perform an oxidation treatment to form a super - hydrophilic CuO nano - coating structure on the surface of the copper foam grids. Embed the copper foam grids into the micro - channels. The process is as described in the attached Figure 6 description. The cleaning liquid in the ultrasonic water bath device is dilute hydrochloric acid, and the oxidation treatment solution is a mixed solution of sodium hydroxide and ammonium persulfate. The conditions for the oxidation treatment are heating in a 70°C water bath for 30 minutes;

[0048] The principle of the oxidation treatment is:

[0049] Cu + 2NaOH+(NH4)2S2O8 → Cu(OH)2+(NH4)2SO4+Na2SO4

[0050] Cu(OH)2 + 2OH - → [Cu(OH)4] 2-

[0051] [Cu(OH)4] 2- → CuO↓+H2O + 2OH - ;

[0052] Among them, the electron microscope characterization diagram of the copper foam grid with the super - hydrophilic CuO nano - coating structure is as shown in the attached Figure 7 description. A large number of nano - sized CuO coatings (nano - flower - like) cover the surface of the copper foam grid. This copper foam grid with a porous CuO nano - coating having super - hydrophilic properties can greatly accelerate liquid replenishment and storage under high - heat - flux conditions;

[0053] S3. Calculate the preferred diameter range of the pore cavities of the nucleate boiling micro - pore array according to the boiling phase - change activation theory. The calculation results are as shown in the attached Figure 3As shown; combined with the specific dimensions of the selected cavity, a planar layout design is carried out, and the design result is as shown in the attached Figure 4 of the specification; finally, according to the design drawing, by means of laser etching, a microporous array is drilled on the surface of the top of the micro-ribbed column, where the attached Figure 5 of the specification is the laser processing cavity array diagram, and it can be seen that the surface of the micro-ribbed column is distributed with a microporous array.

[0054] Example 1

[0055] S1. Divide the single-side copper surface of a 10mm×10mm×10mm standard specimen into a matrix grid array to form micro-ribbed columns and micro-channels with a height difference of 1.2mm; its surface structure diagram is as shown in the attached Figure 2 of the specification. The micro-ribbed columns and micro-channels are alternately distributed on the copper surface, with an edge width of 0.5mm and a normal width of 1.0mm;

[0056] S2. Use a laser cutting machine to cut pure copper foam into a copper foam grid that matches the size of the micro-channel. After cleaning with an ultrasonic water bath device, an oxidation treatment is carried out to form a super-hydrophilic CuO nano-coating structure on the surface of the copper foam grid, and the copper foam grid is embedded into the micro-channel, where the height of the copper foam grid is 0.8mm;

[0057] S3. Calculate the preferred diameter range of the cavity of the nucleate boiling microporous array according to the boiling phase change activation theory. The cavity diameter is 80μm; combined with the specific dimensions of the selected cavity, a planar layout design is carried out, and the center distance between the centers of two micropores is 120μm; finally, according to the design drawing, by means of laser etching, a microporous array is drilled on the surface of the top of the micro-ribbed column.

[0058] Example 2

[0059] S1. Divide the single-side copper surface of a 10mm×10mm×10mm standard specimen into a matrix grid array to form micro-ribbed columns and micro-channels with a height difference of 1.2mm; its surface structure diagram is as shown in the attached Figure 2 of the specification. The micro-ribbed columns and micro-channels are alternately distributed on the copper surface, with an edge width of 0.5mm and a normal width of 1.0mm;

[0060] S2. Use a laser cutting machine to cut pure copper foam into a copper foam grid that matches the size of the micro-channel. After cleaning with an ultrasonic water bath device, an oxidation treatment is carried out to form a super-hydrophilic CuO nano-coating structure on the surface of the copper foam grid, and the copper foam grid is embedded into the micro-channel, where the height of the copper foam grid is 1.0mm;

[0061] S3. Based on the boiling phase change activation theory, the preferred diameter range of the pore size of the micropore array for nucleate boiling is calculated, and the pore diameter is 80μm. Then, based on the specific size of the selected pore, a planar layout design is performed, and the distance between the centers of the two micropores is 120μm. Finally, according to the design drawing, a micropore array is drilled on the surface of the top of the micro-rib column by laser etching.

[0062] Example 3

[0063] S1. Divide the single copper surface of the 10mm×10mm×10mm standard sample into a matrix grid array to form micro-ribs and micro-channels with a height difference of 1.2mm; the surface structure diagram is shown in the attached manual. Figure 2 As shown, micro-ribs and micro-channels are alternately distributed on the copper surface, with an edge width of 0.5 mm and a normal width of 1.0 mm;

[0064] S2, using a laser cutting machine to cut the pure copper foam into a copper foam grid that matches the size of the microchannel, wherein the copper foam grid is cleaned by an ultrasonic water bath device, and then oxidized to form a super-hydrophilic CuO nano-coating structure on the surface of the copper foam grid, and the copper foam grid is embedded in the microchannel, wherein the height of the copper foam grid is 1.2 mm;

[0065] S3. Based on the boiling phase change activation theory, the preferred diameter range of the pore size of the micropore array for nucleate boiling is calculated, and the pore diameter is 80μm. Then, based on the specific size of the selected pore, a planar layout design is performed, and the distance between the centers of the two micropores is 120μm. Finally, according to the design drawing, a micropore array is drilled on the surface of the top of the micro-rib column by laser etching.

[0066] The structures of the samples prepared in Examples 1 to 3 are as shown in the attached manual. Figure 8 As shown. Three samples were tested, and a pool boiling test device was used to continuously provide heat to the test samples on the surface of the hybrid micro / nanostructure matrix array to estimate the surface temperature of the test samples. Figure 9 shown.

[0067] The pool boiling experimental device includes: a boiling water pool cavity 1, a bottom heating module 3, a heat transfer surface performance test part 4, a liquid temperature control unit 5, a data acquisition and processing system 6, a computer 7, a high-speed camera 9 and a high-illuminance lamp 8. The heat transfer surface performance test part 4 is arranged between the boiling water pool cavity 1 and the bottom heating module 3, the boiling water pool cavity 1 is electrically connected to the liquid temperature control unit 5, the heat transfer surface performance test part 4 and the liquid temperature control unit 5 are connected to the data acquisition and processing system 6, and the computer 7 controls the data acquisition and processing system 6, the high-speed camera 9 and the high-illuminance lamp 8.

[0068] At the upper part of the boiling water pool chamber 1, there is a serpentine condenser 13 and a cover plate 11 for maintaining the water level. There are ventilation holes 12 on the cover plate 11. Inside the boiling water pool chamber 1, there is an auxiliary heating rod 15 electrically connected to the liquid temperature control unit 5. The test sample 2 is hermetically fixed to the bottom partition of the boiling water pool chamber 1 using high-temperature resistant glue.

[0069] The bottom heating module 3 includes copper columns 31 and a heating copper base 32 disposed below the copper columns 31. Three T-type thermocouples 41 are inserted into the copper columns 31. Below the heating copper base 32, there is an inserted heating rod 33 (100W×7) to provide heating power for the test sample 2, which is controlled by an AC power regulator.

[0070] The test sample 2 is disposed on the copper columns 31 of the bottom heating module 3. The contact surface between the copper columns 31 and the test sample 2 uses a high thermal conductivity gallium-based liquid alloy 36. The gap between the inserted heating rod 33 and the heating copper base 32 is filled with silicone grease with good thermal conductivity. The outside of the heating copper base 33 is wrapped with mica 34 and alumina high-temperature resistant ceramics 35. The T-type thermocouples 41 are connected to the heat transfer surface performance test part 4.

[0071] During the test, as shown in the attached instruction manual Figure 10 As shown, the test sample 2 is inserted with T-type thermocouples 41 for detecting the temperature of the test sample 2. Three T-type thermocouples 41 are longitudinally inserted into the copper columns 31. The distance Δx between three adjacent T-type thermocouples 41 on the copper columns 31 is 7 mm. The three adjacent T-type thermocouples 41 measure the temperatures of different positions of the copper columns 31 from bottom to top. The distance L between the T-type thermocouple 41 at the middle position of the test sample 2 and the surface of the hybrid micro / nano structure matrix array of the test sample 2 is 4 mm, to measure the temperature in the middle of the test sample 2. Based on the temperatures of the four T-type thermocouples 41, the surface temperature of the hybrid micro / nano structure matrix array of the test sample 2 is deduced. During the test process, the heating power starts from 0 and gradually increases. When boiling bubbles start to appear, a high-speed camera 9 is used to shoot the generation and development behavior of the boiling bubbles. As the power continues to increase, the critical heat flux density (CHF) limit value of the test sample 2 is finally reached.

[0072] After testing, the results show that the CuO foam mesh with a thickness of 1.2 mm has the greatest improvement in the comprehensive heat transfer performance. Compared with the ordinary traditional smooth copper surface, the hybrid micro / nano structure matrix array surface has achieved: triggering the onset of nucleate boiling (ONB) with a nearly 7 °C reduction in the superheat wall temperature, obtaining a maximum 85% increase in the two-phase heat transfer coefficient (HTC), and a growth of up to 226% in the critical heat flux density.

[0073] At the same time, according to the test results, the boiling heat transfer performances of the existing different surfaces are compared with the three samples prepared in the three examples as comparative examples. The results are as shown in the attached instruction manualFigure 11 As shown, nucleate boiling occurs on the surface of the hybrid micro / nano structure matrix array when the wall superheat is only 2°C. Compared with the existing copper-treated surface in the comparative example, the increment of the two-phase heat transfer coefficient HTC is as high as 85%, and the increment of the critical heat flux density CHF is significantly increased by 226% (332.4 W / cm 2 ). It far exceeds the comprehensive heat transfer performance of boiling phase change of other ordinary traditional smooth copper walls or single-structure surfaces.

[0074] Therefore, a hybrid micro / nano structure matrix array surface and its preparation and testing method provided by the present invention can significantly improve the comprehensive performance of boiling heat transfer, and are particularly suitable for application scenarios with high-power cooling requirements such as evaporators, thermal power plants, nuclear reactors, laser weapons, high-power radars, and immersion cooling of data centers.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A hybrid micro / nanostructure matrix array surface, characterized in that: The copper surface is divided into a matrix grid array, wherein the matrix grid array includes micro-ribs as nucleate boiling activation areas and micro-channels as liquid siphon replenishment areas, the surface of the micro-ribs is arranged with a micro-pore array as a boiling activation core, and the micro-channels are arranged at the gaps between the micro-ribs; The micro-ribs are made of pure copper, the micro-channels are filled with copper foam grids, and the height of the copper foam grids is not higher than the height of the micro-ribs; The surface of the copper foam grid is provided with a super-hydrophilic CuO nano-coating structure.

2. A hybrid micro / nanostructure matrix array surface according to claim 1, characterized in that: The cavity radius of the micropore array is 40um to 100um.

3. A method for preparing a hybrid micro / nanostructure matrix array surface based on any one of claims 1 to 2, characterized in that: The following steps are involved: S1, dividing a 10 mm × 10 mm copper surface into a matrix grid array to form micro-ribs and micro-channels with height differences; S2, using a laser cutting machine to cut the pure copper foam into a copper foam grid that matches the size of the microchannel, cleaning it with an ultrasonic water bath device, and then performing an oxidation treatment to form a super-hydrophilic CuO nano-coating structure on the surface of the copper foam grid, and embedding the copper foam grid into the microchannel; S3. Calculate the preferred diameter range of the pore size of the micropore array for nucleate boiling based on the boiling phase change activation theory; then design the planar layout based on the specific size of the selected pores; finally, according to the design drawing, use laser etching to drill the cavity array on the surface of the top of the micro-rib column.

4. The method for preparing a hybrid micro / nanostructure matrix array surface according to claim 3, characterized in that: In step S2, the cleaning solution in the ultrasonic water bath device is dilute hydrochloric acid, the oxidation treatment solution is a mixed solution of sodium hydroxide and ammonium persulfate, and the oxidation treatment condition is heating in a 70° C. water bath for 30 minutes.

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