Steam cavity wick structure and preparation method thereof

Abstract

The invention provides a steam cavity wick structure and a preparation method thereof, and relates to the technical field of heat dissipation structures. The steam cavity wick structure comprises a substrate, a first-stage micro-column array structure composed of a plurality of micro-column structures at equal intervals is arranged on the substrate, and a second-stage micro-pit array structure composed of a plurality of micro-pit structures at equal intervals is arranged on the upper surface of the micro-column structure; the substrate is covered with a nanoneedle cluster-shaped structure. The problems that a traditional steam cavity wick is poor in boiling heat transfer performance, liquid transmission and gas-liquid separation are poor, and a micro-nano structure is difficult to prepare can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation structures, and in particular to a steam chamber liquid absorption core structure and a preparation method thereof. Background Art

[0002] A vapor chamber is a highly efficient passive heat transfer device that exchanges heat through latent heat of phase change. The evaporation end of the chamber undergoes boiling at high heat fluxes. The large amount of latent heat generated during boiling can dissipate significant amounts of heat, making it an ideal heat dissipation method for high-power density electronic devices. The efficient heat dissipation capability of boiling can meet the thermal management requirements of high-heat flux devices such as photovoltaic cells, fast-charging batteries, data centers, and integrated electronic devices.

[0003] The continued growth in energy demand has led to a growing emphasis on achieving higher boiling performance enhancements. Current efforts to enhance boiling heat transfer at the evaporation end of a steam chamber focus on increasing the critical heat flux (CHF) and heat transfer coefficient (HTC). When the CHF is reached, the device surface is covered by a gas film (film boiling). The high thermal resistance of the gas film causes a sudden temperature rise, potentially leading to device burnout.

[0004] The existing evaporation end wick structure design is relatively simple, and most of them can only unilaterally improve CHF or HTC. Structures with a high density of nucleation sites may increase HTC but reduce CHF. Structural designs that enhance capillary force can effectively delay the occurrence of CHF, but it is difficult to take into account the efficiency of HTC.

[0005] In terms of improving boiling performance, high critical heat flux (CHF) requires the surface structure to have high wettability to delay vapor film formation, while high heat transfer coefficient (HTC) requires a large number of vaporization cores on the surface to promote bubble generation. However, there is an inherent contradiction between improving surface wettability and increasing the number of vaporization cores - traditional structural design often finds it difficult to take both into account. Summary of the Invention

[0006] The problem solved by the present invention is how to resolve the inherent contradiction between improving the wettability of the surface of the traditional steam chamber liquid absorbent core and increasing the number of vaporization cores.

[0007] In the first aspect, the present invention provides a steam chamber wick structure, comprising a substrate, on which is provided a primary microcolumn array structure composed of a plurality of equally spaced microcolumn structures, and on the upper surface of the microcolumn structure is provided a secondary micropit array structure composed of a plurality of equally spaced micropit structures; the substrate is covered with a nanoneedle cluster structure.

[0008] Optionally, the cross-section of the microcolumn structure is an isosceles trapezoid, and the upper and lower bases are both square; the width of the lower base of the microcolumn structure is 350 to 550 μm.

[0009] Optionally, there are V-shaped grooves between the primary array micro-column structures; the width of the V-shaped grooves is 50 to 100 μm, and the ratio of the height to the width of the V-shaped grooves is 1.5 to 2.

[0010] Optionally, the depth of the micro-pit structure is 30 to 50 μm, and the top diameter of the micro-pit structure is 10 to 30 μm.

[0011] Optionally, the nanoneedle cluster structure has an average needle-like structure length of 260 to 300 nm, an average width of 30 to 60 nm, and a thickness ranging from 0.4 to 1.2 μm.

[0012] In a second aspect, the present invention provides a method for preparing the above-mentioned steam chamber wick structure, comprising the following steps:

[0013] S1: The optical path of the femtosecond laser is adjusted to an infrared femtosecond laser, and the surface of the substrate is scanned line by line in a vertical cross-line scanning path to etch a micro-pillar structure of the same size and spacing; then, the optical path of the femtosecond laser is adjusted to an ultraviolet femtosecond laser, and a regular micro-pit structure is etched on the top surface of the micro-pillar structure in a circular scanning path;

[0014] S2: Nanoneedle cluster structures are modified on the substrate using boiling water treatment.

[0015] Optionally, in step S1, the wavelength of the infrared femtosecond laser is 1020 to 1040 nm, the average laser power is 32 to 38 W, the scanning speed is 950 to 1050 mm / s, and the repetition frequency is 380 to 430 kHz.

[0016] Optionally, in step S1 , the wavelength of the ultraviolet femtosecond laser is 340 to 360 nm, the average laser power is 2.8 to 3.2 W, the scanning speed is 380 to 420 mm / s, and the repetition frequency is 180 to 220 kHz.

[0017] Optionally, in step S2, the boiling water treatment time is 160 to 200 minutes, and the boiling water temperature is 140 to 160°C.

[0018] Optionally, in step S1, the cross-section of the etched microcolumn structure is an isosceles trapezoid, and the upper and lower bases are both square; the width of the lower base of the microcolumn structure is 350 to 550 μm; the depth of the etched micropit structure is 30 to 50 μm, and the top surface diameter of the micropit structure is 10 to 30 μm; in step S1, an infrared femtosecond laser etches a V-shaped groove between adjacent microcolumn structures; wherein the width of the V-shaped groove is 50 to 100 μm, and the ratio of the height to the width of the V-shaped groove is 1.5 to 2; the average length of the needle-like structure of the nanoneedle cluster structure is 260 to 300 nm, the average width is 30 to 60 nm, and the thickness ranges from 0.4 to 1.2 μm.

[0019] The beneficial effects of a steam chamber wick structure and its preparation method of the present invention are: a hierarchical integrated design of a primary microcolumn array structure, a secondary micropit array structure and a nanoneedle cluster structure. The primary microcolumn array structure constitutes a spatial skeleton and forms a V-groove channel between the columns, which serves as the main capillary rehydration path to support continuous liquid supply; the secondary micropit array structure with regular arrangement on the top surface of the primary microcolumn array structure provides a high-density vaporization core to promote the start-up of bubbles at a lower superheat; the secondary micropit array structure and the nanoneedle cluster structure covered on the V-groove further expand the channel area of the capillary-driven liquid, while increasing the thin liquid film evaporation area and improving the latent heat transfer efficiency. During the boiling process, the larger bubbles generated at the bottom of the V-groove detach first, have higher buoyancy and inertia, and can swallow up small bubbles that have not yet grown or are trapped in the micropits, thereby forming a bubble cooperative detachment mechanism, significantly improving the bubble discharge rate, and avoiding surface dry spots and vapor film coverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic structural diagram of a steam chamber liquid wick structure of the present invention.

[0021] Figure 2 Schematic diagram of the dynamic process of boiling bubbles regulated by the wick structure at the middle evaporation end.

[0022] Figure 3 for Figure 1 Partial side view of area A in the middle.

[0023] Figure 4 The present invention is a flow chart of a method for preparing a steam chamber liquid wick structure.

[0024] Figure 5 Schematic diagram of the preset scanning path for laser texturing.

[0025] Figure 6 Schematic diagram of the surface morphology of the wick structure and the underwater gas contact angle.

[0026] Description of reference numerals:

[0027] 1. Substrate; 2. Primary array micropillar structure; 3. V-shaped groove; 4. Secondary micropit array structure; 5. Nanoneedle cluster tertiary structure; 6. Detached bubbles generated by the V-shaped groove; 7. Bubbles generated by the secondary micropit array structure; 8. Secondary liquid supply path; 9. Primary liquid supply path. DETAILED DESCRIPTION

[0028] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the present invention description are only for the purpose of describing specific embodiments and are not intended to limit the present invention;

[0030] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "multiple" means two or more.

[0031] In the related technology, a Chinese invention patent discloses a microscale synergistic surface structure for enhancing boiling heat transfer (application number 201910241520.4), in which the substrate surface is divided by ribs to form large grooves, small grooves and connecting grooves, and the small grooves are modified by a low surface energy superhydrophobic coating of a fluoropolymer to achieve the purpose of generating a vaporization core at a lower superheat. However, the structure of this groove has a constant cross-section in the vertical direction, which is not conducive to the vertical rise and detachment process of the bubble. In addition, this bonding method through non-covalent bond adsorption results in poor bonding strength of the coating, which is easily damaged by water erosion or mechanical friction, and is prone to failure in actual applications in harsh environments such as aerospace.

[0032] A Chinese invention patent discloses a non-uniform fractal micro-pit structure and super-hydrophilic composite surface for enhancing boiling heat transfer (application number 202411528872.5). The micro-pit structure is etched by nanosecond laser to provide a large number of vaporization cores, and is etched using NaClO2, NaOH, and Na3PO4 chemical solutions. This method is highly dangerous and environmentally polluting, and the capillary force of the formed nanostructure is weak, which cannot significantly increase CHF.

[0033] A Chinese invention patent discloses a micro-nano multi-scale structure for surface-enhanced boiling heat transfer and its manufacturing method (application number 202210582471.2). Efficient cooling liquid replenishment is achieved by combining micro-protrusion units with nanostructures. Although this design is beneficial for delaying the occurrence of critical heat flux density, it cannot guarantee the formation of a large number of vaporization cores in the early stage of boiling, and thus cannot achieve a high heat transfer coefficient in the boiling stage.

[0034] Therefore, how to design a surface micro-nanostructure that can regulate the dynamic behavior of boiling bubbles, so that they form a dense vaporization core at low heat flux density, and effectively delay bubble film formation at high heat flux density to increase CHF, has become a key challenge in the current field of boiling surface structure design and manufacturing. At the same time, in terms of structural preparation, the processing methods used in existing technologies to improve boiling heat transfer performance have obvious shortcomings: for example, the process steps based on the template method are cumbersome (such as involving photolithography, electroforming and other processes), making it difficult to achieve large-scale commercial production; and the chemical method, due to the use of highly corrosive reagents, poses environmental pollution and safety risks.

[0035] In view of the problems existing in the above-mentioned related technologies, an embodiment of the present invention provides a steam chamber liquid wick structure and a preparation method thereof.

[0036] like Figures 1 to 3 As shown, a steam chamber wick structure provided by one embodiment of the present invention includes: a substrate 1, a primary microcolumn array structure composed of a plurality of equally spaced microcolumn structures 2 is provided on the substrate 1, and a secondary micropit array structure composed of a plurality of equally spaced micropit structures 4 is provided on the upper surface of the microcolumn structure 2; the substrate 1 is covered with a nanoneedle cluster structure 5.

[0037] The substrate 1 is made of pure aluminum or aluminum alloy, and the maximum substrate size range is 150 mm*150 mm.

[0038] In this embodiment, a combination of a primary micropillar array structure, a secondary micropit array structure, and a nanoneedle cluster structure is used. This multi-level structural design can provide a rich variety of surface morphologies and functional properties. The primary micropillar array structure can increase the surface area and improve the adsorption and transmission capacity of the liquid; the secondary micropit array structure can provide a large number of vaporization cores, which is conducive to promoting the generation of bubbles under low heat flux density and improving the heat transfer coefficient (HTC); the rich nanoneedle cluster structure forms a secondary liquid replenishment channel 8, while expanding the area of thin liquid film evaporation, thereby increasing the critical heat flux (CHF), effectively taking into account the improvement of HTC and CHF. The substrate 1 is made of pure aluminum or aluminum alloy, which has good thermal conductivity and can quickly transfer heat from the heat source to the liquid wick structure, thereby improving the heat dissipation efficiency. At the same time, aluminum and aluminum alloy materials also have the advantages of light weight, high strength, and corrosion resistance, and are suitable for a variety of application scenarios, especially in fields with high requirements for weight and reliability, such as aerospace.

[0039] Alternatively, as Figure 3 As shown, the cross-section of the micropillar structure 2 (a cross-section perpendicular to the substrate) is an isosceles trapezoid, with both the upper and lower bases (i.e., the two opposing surfaces of the micropillar structure 2 parallel to the substrate) being square. The width W3 of the lower base of the micropillar structure 2 is 350 to 550 μm. V-shaped grooves 3 are formed between adjacent micropillar structures 2; the width W1 of the V-shaped grooves 3 is 50 to 100 μm, and the ratio H1 / W1 of the height H1 to the width W1 of the V-shaped grooves 3 is 1.5 to 2.

[0040] In this embodiment, the width of the microcolumnar structure 2 can not only ensure structural strength, but also increase the specific surface area, thereby enhancing the liquid absorption and heat transfer capabilities; the V-shaped groove 5 formed between the microcolumnar structures 2 can form a main liquid replenishment channel 9. The width of the V-shaped groove 5 is conducive to rapid liquid transmission and gas-liquid exchange, while the ratio of height to width can reasonably store liquid and optimize the bubble escape path.

[0041] Optionally, the depth H2 of the micro-pit structure 4 is 30 to 50 μm, and the top surface diameter W2 of the micro-pit structure 4 is 10 to 30 μm.

[0042] Optionally, the average length of the needle-like structures of the nanoneedle cluster structure 5 is 260 to 300 nm, the average width is 30 to 60 nm, and the thickness ranges from 0.4 to 1.2 μm.

[0043] In this embodiment, the depth of the micro-pit structure 4 can stabilize the gas-liquid interface and promote the formation of vaporization cores under low heat flux density. The size of the top surface diameter can increase the micro-pit density and the frequency of bubble generation. The sizes of each part cooperate with each other to jointly achieve efficient heat transfer and heat dissipation performance.

[0044] Since the heat flow reaches the bottom of the V-shaped groove 3 first, when the bubbles 7 generated by the micro-pit structure 4 begin to grow, the detached bubbles 6 generated by the V-shaped groove 3 are much larger than the bubbles 7 generated by the micro-pit structure 4. Due to the coordinated detachment mechanism of the bubbles, the detached bubbles 6 have higher buoyancy and inertia. During the floating process, they will swallow up small bubbles 7 that have not yet grown or are trapped in the micro-pits, thereby driving the small bubbles 7 to accelerate their detachment from the surface, which helps to quickly remove bubbles on the heating surface and avoid local dry spots.

[0045] On the vapor chamber wick structure, the nanoneedle cluster structure forms a secondary liquid replenishment channel 8, and the V-shaped groove 5 can form a main liquid replenishment channel 9. The liquid can flow in the above-mentioned channel. The secondary liquid supply path 8 and the main liquid supply path 9 cooperate to re-wet the surface, forming gas channels and liquid channels that do not affect each other during the boiling heat transfer process, effectively solving the liquid replenishment obstacles caused by bubble congestion in the traditional structure, improving the structure's resistance to dry spots and film states, significantly delaying the triggering of CHF, and greatly improving the boiling phase change heat transfer performance.

[0046] like Figure 4 and 5 As shown, a method for preparing a steam chamber wick structure provided by one embodiment of the present invention includes the following steps:

[0047] S1: The optical path of the femtosecond laser is adjusted to an infrared femtosecond laser, and the surface of the substrate 1 is scanned line by line in a vertical cross-line scanning path to etch micro-pillar structures 2 of the same size and spacing; then, the optical path of the femtosecond laser is adjusted to an ultraviolet femtosecond laser, and a regular micro-pit structure 4 is etched on the top surface of the micro-pillar structure 2 in a circular scanning path;

[0048] S2: A nanoneedle cluster structure is modified on substrate 1 by using boiling water treatment.

[0049] In this embodiment, the femtosecond laser includes an infrared femtosecond laser and an ultraviolet femtosecond laser dual path, with a pulse width of 218fs-5ps. It can realize one-key switching of the infrared femtosecond and ultraviolet femtosecond dual optical path systems, without the need for secondary dimming and without the need to dismantle the sample to be processed to operate normally, thereby improving processing efficiency. Infrared femtosecond laser has the advantages of high power and high efficiency, and is suitable for rapid etching of large-area micro-pillar structures, such as Figure 5As shown in the figure, the infrared femtosecond laser scans the substrate along the horizontal and vertical straight lines and etches the micro-pillar structure line by line with vertical cross lines. The ultraviolet femtosecond laser can achieve sub-micron precision morphology control and can further process more fine micro-pit structures on the top surface of the micro-pillar structure, such as Figure 5 As shown, a UV femtosecond laser etches a micropit structure along a circular path on the top surface of the micropillar structure. The narrow pulse width and high peak power of the femtosecond laser allow for high-precision control of structural parameters, along with a well-defined etching path and simple operation. Subsequently, an environmentally friendly boiling water treatment is used. The dense Al atoms on the aluminum surface adsorb Al-O atoms, which are deposited on the microstructure surface, inducing the formation of needle-like boehmite crystals, forming a nanoneedle cluster structure with high capillary force. This simple boiling water treatment can modify the nanoneedle cluster structure without the use of corrosive chemicals. The process is simple and efficient, significantly improving production efficiency, reducing costs, and possessing industrial scalability.

[0050] Optionally, in step S1, the wavelength of the infrared femtosecond laser is 1000 to 1060 nm, the average laser power is 32 to 38 W, the scanning speed is 950 to 1050 mm / s, and the repetition frequency is 380 to 430 kHz.

[0051] Preferably, the wavelength of the infrared femtosecond laser is 1030 nm, the average laser power is 35 W, the scanning speed is 1000 mm / s, and the repetition frequency is 400 kHz.

[0052] Optionally, in step S1 , the wavelength of the ultraviolet femtosecond laser is 340 to 360 nm, the average laser power is 2.8 to 3.2 W, the scanning speed is 380 to 420 mm / s, and the repetition frequency is 180 to 220 kHz.

[0053] Preferably, the wavelength of the ultraviolet femtosecond laser is 355 nm, the average laser power is 3 W, the scanning speed is 400 mm / s, and the repetition frequency is 200 kHz.

[0054] Optionally, in step S2, the boiling water treatment time is 160 to 200 minutes, and the boiling water temperature is 140 to 160°C.

[0055] Preferably, the boiling water treatment time is 180 min and the boiling water temperature is 150°C.

[0056] In this embodiment, the parameters described above have been carefully designed and play a key role in the quality and efficiency of the steam chamber wick structure fabrication. Within this parameter range, an infrared femtosecond laser can efficiently etch micropillar structures on the substrate, with optimized parameters further improving the dimensional accuracy and surface quality of the micropillar structures. Within this parameter range, an ultraviolet femtosecond laser can finely process micropits on the top surfaces of the micropillar structures, with optimized values resulting in a more uniform distribution and regular morphology of the micropits. Within this parameter range, a boiling water treatment creates optimal conditions for the modification of nanoneedle clusters, ensuring their full growth. Optimized parameters further optimize the nanoneedle cluster structure and enhance the boiling heat transfer performance of the wick.

[0057] Optionally, in step S1, the cross-section of the etched microcolumn structure 2 (the cross-section perpendicular to the substrate) is an isosceles trapezoid, the upper base and the lower base (i.e., the two opposite surfaces of the microcolumn structure 2 parallel to the substrate) are both squares, and the width of the lower base of the microcolumn structure 2 is 350 to 550 μm; the depth of the etched micropit structure is 30 to 50 μm, and the top surface diameter of the micropit structure is 10 to 30 μm.

[0058] Optionally, in step S1 , an infrared femtosecond laser is used to etch a V-shaped groove between adjacent microcolumn structures 2 ; wherein the width of the V-shaped groove is 50 to 100 μm, and the ratio of the height to the width of the V-shaped groove is 1.5 to 2.

[0059] In this embodiment, the above parameters can achieve a balance between vaporization core density and liquid replenishment capacity in boiling heat transfer, while taking into account both processing efficiency and structural reliability, providing an ideal solution for high-performance steam chamber wicks.

[0060] The present invention is further described below with reference to specific embodiments.

[0061] Example 1

[0062] like Figure 6 As shown, in a contact angle test of a vapor chamber wick structure according to the present invention, a sample is placed in deionized water with the surface of the structure facing downward. A syringe is used to inject 5 μL of air into the water below the sample. The contact angle obtained when the bubbles generated by the syringe come into contact with the surface structure is the underwater air contact angle.

[0063] The test results show a large underwater gas contact angle (CA = 153°), indicating that the wick structure has good gas repellency. During the boiling heat transfer process, this gas repellency facilitates the rapid detachment of gas (steam bubbles) from the surface, reducing the time bubbles remain attached to the surface and preventing gas from accumulating and forming a film on the surface, thereby preventing heat transfer degradation and increasing the critical heat flux (CHF).

[0064] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A steam chamber wick structure, characterized in that: The invention comprises a substrate (1), wherein a primary micro-column array structure composed of a plurality of equally spaced micro-column structures (2) is provided on the substrate (1), and a secondary micro-pit array structure composed of a plurality of equally spaced micro-pit structures (4) is provided on the upper surface of the micro-column structure (2); and the substrate (1) is covered with a nano-needle cluster structure (5).

2. The steam chamber wick structure according to claim 1, characterized in that: The cross section of the micro-column structure (2) is an isosceles trapezoid, and the upper and lower base surfaces are both square; the width of the lower base surface of the micro-column structure (2) is 350 to 550 μm.

3. The steam chamber wick structure according to claim 1, characterized in that: V-shaped grooves (3) are formed between the micro-column structures (2); the width of the V-shaped grooves (3) is 50 to 100 μm, and the ratio of the height to the width of the V-shaped grooves (3) is 1.5 to 2.

4. The steam chamber wick structure according to claim 1, characterized in that: The depth of the micro-pit structure (4) is 30 to 50 μm, and the top surface diameter of the micro-pit structure (4) is 10 to 30 μm.

5. The steam chamber wick structure according to claim 1, characterized in that: The average needle-like structure length of the nano-needle cluster structure (5) is 260 to 300 nm, the average width is 30 to 60 nm, and the thickness ranges from 0.4 to 1.2 μm.

6. A method for preparing a steam chamber wick structure according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: The optical path of the femtosecond laser is adjusted to an infrared femtosecond laser, and the surface of the substrate is scanned line by line in a vertical cross-line scanning path to etch a micro-pillar structure of the same size and spacing; then, the optical path of the femtosecond laser is adjusted to an ultraviolet femtosecond laser, and a regular micro-pit structure is etched on the top surface of the micro-pillar structure in a circular scanning path; S2: Nanoneedle cluster structures are modified on the substrate using boiling water treatment.

7. The method for preparing a steam chamber wick structure according to claim 6, wherein: In step S1 , the wavelength of the infrared femtosecond laser is 1020 to 1040 nm, the average laser power is 32 to 38 W, the scanning speed is 950 to 1050 mm / s, and the repetition frequency is 380 to 430 kHz.

8. The method for preparing a steam chamber wick structure according to claim 5, wherein: In step S1 , the wavelength of the ultraviolet femtosecond laser is 340 to 360 nm, the average laser power is 2.8 to 3.2 W, the scanning speed is 380 to 420 mm / s, and the repetition frequency is 180 to 220 kHz.

9. The method for preparing a steam chamber wick structure according to claim 6, wherein: In step S2, the boiling water treatment time is 160 to 200 minutes, and the boiling water temperature is 140 to 160°C.

10. The method for preparing a steam chamber wick structure according to claim 6, wherein: In step S1, the cross-section of the etched micro-column structure is an isosceles trapezoid, and the upper and lower bases are both square; the width of the lower base of the micro-column structure is 350 to 550 μm; The depth of the etched micro-pit structure is 30 to 50 μm, and the top surface diameter of the micro-pit structure is 10 to 30 μm; the infrared femtosecond laser etches V-shaped grooves between adjacent micro-column structures; wherein, the width of the V-shaped groove is 50 to 100 μm, and the ratio of the height to the width of the V-shaped groove is 1.5 to 2; the average length of the needle-like structure of the nanoneedle cluster structure is 260 to 300 nm, the average width is 30 to 60 nm, and the thickness ranges from 0.4 to 1.2 μm.

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