Heat plate and manufacturing method thereof, electronic device

Abstract

The application relates to the heat dissipation technical field, in particular to a vapor chamber and a manufacturing method thereof and an electronic device, wherein the manufacturing method of the vapor chamber comprises the following steps: providing a metal mesh, cutting the metal mesh into a predetermined size to obtain a wick; providing a first shell, fixing at least one layer of the wick on the inner wall surface of the first shell, and forming a capillary structure by the at least one layer of the wick; arranging a hydrophilic layer on the surface of the capillary structure; providing a second shell, arranging a hydrophobic layer on the inner wall surface of the second shell; fixing the first shell and the second shell to form a cavity, and arranging the capillary structure in the cavity between the first shell and the second shell; injecting a working medium into the cavity formed by the first shell and the second shell, and sealing after vacuumizing to obtain the vapor chamber. By arranging the hydrophilic layer on the surface of the capillary structure and arranging the hydrophobic layer on the inner wall surface of the second shell, the wettability regulation ability of the vapor chamber can be improved, and the gas-liquid circulation efficiency of the working medium in the vapor chamber can be optimized.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology, and more particularly to heat spreaders and their manufacturing methods, as well as electronic devices. Background Technology

[0002] As electronic devices rapidly evolve towards thinner, lighter, and higher-performance designs, chip heat flux density continues to surge, placing increasingly stringent demands on the heat dissipation efficiency and ultra-thin adaptability of vapor chambers. The wick, as a core functional component of the vapor chamber's heat transfer performance, directly determines the gas-liquid circulation efficiency and heat dissipation effect. Metal mesh, with its advantages of adaptability to ultra-thin designs, controllable cost, and convenient molding, has become the mainstream wick structure.

[0003] During the fabrication of a vapor chamber, an oxide layer easily forms between the metal mesh (capillary structure) and the top cover plate during high-temperature processes such as bonding and welding. This not only increases interfacial thermal resistance but also clogs capillary pores, severely weakening the heat transfer performance of the vapor chamber. Existing technologies often address the issue of surface energy regulation within the vapor chamber cavity by adding an oxidation-reduction process. However, this method only achieves a uniform hydrophilic treatment of the entire inner surface of the cavity. On the one hand, it extends the production cycle, increases equipment and consumable costs, and requires strict control over the process exposure time, significantly increasing process complexity and mass production difficulty, making it unsuitable for large-scale production. On the other hand, the strong hydrophilic state of the entire inner surface of the cavity easily leads to residual working fluid droplets and poor gas phase discharge, further exacerbating gas-liquid circulation resistance and restricting the improvement of the vapor chamber's heat dissipation performance. Summary of the Invention

[0004] This application proposes a heat spreader and its manufacturing method and electronic equipment, aiming to solve the problem of easy oxidation of capillary structure during the manufacturing process of heat spreader, improve the wettability control capability of heat spreader, and improve the heat dissipation performance of heat spreader.

[0005] In a first aspect, embodiments of this application provide a method for manufacturing a heat spreader, comprising the following steps: A metal mesh is provided, and the metal mesh is cut to the desired size to obtain a liquid-absorbing core; A first housing is provided, and at least one layer of the liquid-absorbing core is disposed on the inner wall surface of the first housing, wherein the at least one layer of the liquid-absorbing core forms the capillary structure; A hydrophilic layer is provided on the surface of the capillary structure; A second housing is provided, and a hydrophobic layer is provided on the inner wall surface of the second housing; The first housing and the second housing are fixed to form a cavity, and the capillary structure is located in the cavity between the first housing and the second housing; A working fluid is injected into the cavity formed by the first shell and the second shell, and after evacuation, it is sealed to obtain a heat spreader.

[0006] In some embodiments, a hydrophilic layer is formed on the surface of the capillary structure using chemical vapor deposition, wherein the precursor gas used includes at least one selected from tetraethyl orthosilicate, tetramethylsilane, hexamethyldisiloxane, titanium tetrachloride, titanium isopropoxide, tetra(dimethylamino)titanium, trimethylaluminum, triethylaluminum, and triisopropylaluminum, and the reactant gas used includes at least one selected from oxygen, nitrous oxide, and ammonia; or, A hydrophilic layer is formed on the surface of the capillary structure by magnetron sputtering. The sputtering target is selected from any one of silicon dioxide ceramic target, titanium dioxide ceramic target, pure titanium metal target, aluminum oxide ceramic target, pure aluminum metal target, silicon oxynitride ceramic target, and single crystal silicon target. The reaction gas used includes at least one of oxygen and nitrogen.

[0007] In some embodiments, a hydrophobic layer is formed on the inner wall surface of the second shell using chemical vapor deposition. The precursor gas used includes a titanium-containing precursor and / or a fluorine-containing precursor. The titanium-containing precursor includes at least one of titanium tetrachloride, titanium isopropoxide, and tetra(dimethylamino)titanium. The fluorine-containing precursor includes at least one of carbon tetrafluoride, sulfur hexafluoride, trifluoromethane, hexafluoroethane, and perfluorobutane. The reaction gas used includes at least one of oxygen, nitrous oxide, argon, and nitrogen. Alternatively, A hydrophobic layer is formed on the inner wall surface of the second shell using magnetron sputtering. The sputtering target is selected from any one of the following: fluorine-doped titanium dioxide ceramic target, composite target of titanium dioxide ceramic target and magnesium fluoride ceramic target, titanium fluoride ceramic target, polytetrafluoroethylene polymer target, organosilicon ceramic target, and siloxane composite target. The reaction gas used includes at least one of oxygen, carbon tetrafluoride, and nitrogen.

[0008] In some embodiments, the hydrophilic layer comprises at least one material selected from silicon dioxide, titanium dioxide, aluminum oxide, and silicon oxynitride; and / or, The hydrophobic layer comprises fluorine-doped titanium dioxide (TiO2:F) and fluorinated carbon (CF2). x At least one of the following materials: polysiloxane (organosilicon) hydrophobic layer.

[0009] In some embodiments, the fluorine doping content in the fluorine-doped titanium dioxide is 1.0~3.0 at%.

[0010] In some embodiments, the liquid-absorbing core is fixed to the inner wall surface of the first housing in a manner selected from any one of inert atmosphere sintering, adhesive fixing, and spot welding; and / or, The fixing method of the first housing and the second housing is selected from any one of laser welding, diffusion welding, and brazing.

[0011] In some embodiments, the inert atmosphere contains a reducing gas.

[0012] In some embodiments, after fixing the first housing and the second housing, the manufacturing method further includes the step of: injecting a working fluid into the cavity formed by the first housing and the second housing, evacuating the vacuum, and sealing it to obtain a heat spreader.

[0013] In some embodiments, the total thickness of the capillary structure is 0.04 to 2 mm.

[0014] In some embodiments, the thickness of the metal mesh is 0.04~0.15 mm.

[0015] In some embodiments, the wire diameter of the metal mesh is 0.005~0.1 mm.

[0016] In some embodiments, the porosity of the metal mesh is 60-95%.

[0017] In some embodiments, the mesh count of the metal mesh is 80 to 500 mesh.

[0018] In some embodiments, a plurality of support columns are protruding from the inner wall surface of the second housing. After the first housing and the second housing are fixed, the end of the support column away from the second housing abuts against the capillary structure or the first housing.

[0019] In some embodiments, a first injection tank is provided on the first housing and a second injection tank is provided on the second housing. After the first housing and the second housing are fixed, the first injection tank and the second injection tank are arranged opposite to each other and spliced ​​together to form an injection pipe for injecting working fluid into the heat spreader.

[0020] In some embodiments, the thickness of the hydrophilic layer is 100~400 nm.

[0021] In some embodiments, the thickness of the hydrophobic layer is 100~400 nm.

[0022] In some embodiments, the thickness of the first housing is 0.05 to 5 mm.

[0023] In some embodiments, the thickness of the second housing is 0.05 to 5 mm.

[0024] Secondly, this application also proposes a heat spreader, comprising: The housing includes a first housing and a second housing, the first housing and the second housing enclosing a cavity; A capillary structure is disposed in the cavity and fixed to the side of the first housing facing the second housing, the capillary structure comprising at least one liquid-absorbing core; The capillary structure is provided with a hydrophilic layer, and the inner wall surface of the second shell is provided with a hydrophobic layer.

[0025] Thirdly, this application also proposes an electronic device comprising a heat spreader prepared by the manufacturing method described in the first aspect.

[0026] Compared with the prior art, this technical solution has at least the following technical advantages: In this application's technical solution, the capillary structure is made of a metal mesh. The metal mesh capillary structure offers advantages such as adaptability to ultra-thin designs, controllable cost, and convenient molding, which helps improve the gas-liquid circulation efficiency and heat dissipation effect of the heat exchanger. By setting a hydrophilic layer on the surface of the capillary structure, high-temperature oxidation of the capillary structure during heat exchanger fabrication can be avoided, preventing increased thermal resistance and capillary pore blockage, thus improving the heat transfer performance of the heat exchanger. Furthermore, by setting a hydrophilic layer on the surface of the capillary structure and a hydrophobic layer on the inner wall of the second shell, the wettability control capability of the heat exchanger is improved: the hydrophilic layer enhances the hydrophilicity of the capillary structure, accelerating the transfer efficiency of the working fluid within it; the hydrophobic layer enhances the hydrophobicity of the second shell, reducing droplet residue and promoting gas phase discharge. The hydrophilic and hydrophobic layers synergistically optimize the gas-liquid circulation efficiency of the working fluid within the heat exchanger. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1 This is a process flow diagram of the manufacturing process of the heat spreader in some embodiments of this application; Figure 2 This is a schematic diagram of the heat spreader of this application in some embodiments; Figure 3 for Figure 2 Exploded view; Figure 4 for Figure 3 A structural diagram from another perspective; Figure 5 for Figure 4 Enlarged view of part B; Figure 6 for Figure 2 Top view; Figure 7 for Figure 6 Sectional view along axis AA; Figure 8 for Figure 7 Enlarged view of part C; Figure 9 for Figure 2A schematic diagram showing the connection between the capillary structure and the first shell. Figure 10 This is a schematic diagram of the capillary structure of this application in some embodiments.

[0029] Figure label: 100-Heating plate, 101-Injection trough (first injection tank / second injection tank), 102-Cavity, 110-First shell, 120-Second shell, 121-Support column, 130-Capillary structure, 131-Suction core. Detailed Implementation

[0030] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0032] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0034] In existing vapor chamber manufacturing processes, an oxide layer easily forms between the metal mesh and the shell during high-temperature processes such as bonding and welding. This not only increases interfacial thermal resistance but also clogs capillary pores, severely weakening the heat transfer performance of the vapor chamber. Current technologies often address the issue of surface energy regulation within the vapor chamber cavity by adding an oxidation-reduction process. However, this method only achieves a uniform hydrophilic treatment of the entire inner surface of the cavity. On the one hand, it extends the production cycle, increases equipment and material costs, and requires strict control over process exposure time, significantly increasing process complexity and mass production difficulty, making it unsuitable for large-scale production. On the other hand, a highly hydrophilic inner surface easily leads to residual working fluid droplets and impeded gas phase discharge, further exacerbating gas-liquid circulation resistance and restricting the improvement of the vapor chamber's heat dissipation performance.

[0035] While there have been many innovative attempts in related technologies, these technologies either focus on structural optimization or specific material modification, and none of them have fundamentally solved the problem of synergistic effect between high-temperature oxidation of metal mesh and process simplification.

[0036] Therefore, developing a manufacturing method that can fundamentally solve the problem of high-temperature oxidation of metal mesh, simultaneously simplify the production process and reduce manufacturing costs has become a key challenge that urgently needs to be overcome in this field.

[0037] Based on this, in the first aspect, this application proposes a method for manufacturing a heat spreader 100.

[0038] Please see Figures 1-10 In this embodiment of the application, the method for manufacturing the heat spreader 100 includes the following steps: S10. Provide a metal mesh and cut the metal mesh to the expected size to obtain a liquid-absorbing core 131; S20. A first housing 110 is provided, and at least one layer of the liquid-absorbing core 131 is fixed to the inner wall surface of the first housing 110, wherein the at least one layer of the liquid-absorbing core 131 forms a capillary structure 130; S30. A hydrophilic layer is provided on the surface of the capillary structure 130; S40. A second housing 120 is provided, and a hydrophobic layer is provided on the inner wall surface of the second housing 120; S50. The first housing 110 and the second housing 120 are fixed to form a cavity, and the capillary structure 130 is located in the cavity between the first housing 110 and the second housing 120; S60. Inject working fluid into the cavity 102 formed by the first housing 110 and the second housing 120, evacuate and seal it to obtain a heat spreader 100.

[0039] In this embodiment, the heat spreader 100 has a first housing 110 and a second housing 120 forming a closed cavity 102, within which the working fluid circulates. In some embodiments, the first housing 110 is flat, and the second housing 120 is recessed in the middle. The recessed sides of the first housing 110 and the second housing 120 are fitted together to form the cavity 102, meaning the depth of the recess in the second housing 120 is the width / height of the cavity 102.

[0040] In this embodiment, the inner wall surface of the first housing 110 refers to the wall surface located inside the heat spreader 100 after being assembled with the second housing 120 to form the heat spreader 100; the inner wall surface of the second housing 120 refers to the wall surface located inside the heat spreader 100 after being assembled with the first housing 110 to form the heat spreader 100.

[0041] In this application's technical solution, by providing a hydrophilic layer on the surface of the capillary structure 130, the high-temperature oxidation of the capillary structure 130 during the fabrication of the heat spreader 100 can be avoided, which would lead to increased thermal resistance and blockage of capillary pores, thus improving the heat transfer performance of the heat spreader 100. Furthermore, by providing a hydrophilic layer on the surface of the capillary structure 130 and a hydrophobic layer on the inner wall of the second shell 120, the wettability control capability of the heat spreader 100 is improved: the hydrophilic layer enhances the hydrophilicity of the capillary structure 130, accelerating the transfer efficiency of the working fluid within it; the hydrophobic layer enhances the hydrophobicity of the second shell 120, reducing droplet residue and promoting gas phase discharge. The hydrophilic and hydrophobic layers synergistically optimize the gas-liquid circulation efficiency of the working fluid within the heat spreader 100.

[0042] Furthermore, the manufacturing method of this application has the advantage of simple process. By providing a hydrophilic layer on the capillary structure 130 and a hydrophobic layer on the second shell 120, this application simultaneously solves the problems of easy oxidation of the capillary structure 130 and uneven distribution of surface energy within the cavity 102 of the heat spreader 100. Therefore, the manufacturing method of the heat spreader 100 of this application does not require an additional oxidation-reduction process or control of the opening exposure time of the second shell 120, greatly simplifying the production process and reducing the difficulty and cycle time of mass production.

[0043] The embodiments of this application will be described in more detail below: S10. Provide a metal mesh and cut the metal mesh to the expected size to obtain a liquid absorbent core 131.

[0044] In this embodiment, the material of the metal mesh can be selected from any one or more of copper alloy, stainless steel, and steel-copper alloy. The metal mesh is woven from several metal wires of the same or similar diameter in a warp and weft interlacing manner.

[0045] In some embodiments, the thickness of the metal mesh is 0.04~0.15 mm, specifically 0.04 mm, 0.10 mm, 0.15 mm, or any value between them. The wire diameter of the metal mesh is 0.005~0.1 mm, specifically 0.005 mm, 0.01 mm, 0.05 mm, 0.1 mm, or any value between them. The porosity of the metal mesh is 60~95%, specifically 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or any value between them. The mesh count of the metal mesh is 80~500 mesh, specifically 80 mesh, 100 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh, 500 mesh, or any value between them.

[0046] S20. A first housing 110 is provided, and at least one layer of the absorbent core 131 is fixed to the inner wall surface of the first housing 110, wherein the at least one layer of the absorbent core 131 forms a capillary structure 130.

[0047] In this embodiment, the capillary structure 130 is made of a metal mesh liquid-absorbing core 131. The metal mesh liquid-absorbing core 131 has advantages such as adaptability to ultra-thin design, controllable cost, and convenient molding, which is conducive to improving the gas-liquid circulation efficiency and heat dissipation effect of the heat spreader 100.

[0048] In the embodiments of this application, please refer to Figure 6 The capillary structure 130 includes at least one layer of the liquid-absorbing core 131. Preferably, the capillary structure 130 includes multiple layers of liquid-absorbing cores 131 stacked together. This arrangement increases the mesh count of the capillary structure 130. With the total thickness of the capillary structure 130 remaining constant, the mesh count of the multi-layer liquid-absorbing core 131 is higher than that of the single-layer liquid-absorbing core 131. As the mesh count increases, the capillary pressure increases, the capillary climbing ability of the capillary structure 130 becomes stronger, and the suction coefficient and volumetric flow rate also increase, which is more conducive to accelerating the gas-liquid circulation of the working fluid within the heat exchanger 100 and improving the heat dissipation effect of the heat exchanger 100.

[0049] In some embodiments, the total thickness of the capillary structure 130 is 0.04 to 2 mm, specifically 0.04 mm, 0.08 mm, 0.12 mm, 0.16 mm, 2 mm, or any value between them. The material of the first housing 110 can be selected from one or more of copper alloy, stainless steel, steel-copper alloy, or other materials commonly used in the art. The method by which the capillary structure 130 is fixed to the inner wall surface of the first housing 110 is selected from any one of inert atmosphere sintering, adhesive fixing, and spot welding. Inert atmosphere sintering, adhesive fixing, and spot welding can prevent the metal of the capillary structure 130 from being oxidized.

[0050] In one embodiment, the capillary structure 130 is composed of a single-layer absorbent core 131, and the capillary structure 130 / absorbent core 131 is fixed to the inner wall of the first housing 110 by sintering in an inert atmosphere or by adhesive bonding. In another embodiment, the capillary structure 130 is composed of multiple layers of absorbent cores 131 stacked together, and the capillary structure 130 / absorbent core 131 is fixed to the inner wall of the first housing 110 by sintering in an inert atmosphere or by spot welding. This arrangement allows the multiple layers of absorbent cores 131 to be fixed together, saving processes and time.

[0051] In some embodiments, the capillary structure 130 is fixed to the inner wall of the first housing 110 by sintering in an inert atmosphere. The sintering has a heating stage, a holding stage, and a cooling stage performed sequentially. The heating rate of the heating stage is 30~70 ℃ / min, specifically 30 ℃ / min, 40 ℃ / min, 50 ℃ / min, 60 ℃ / min, 70 ℃ / min, or any value between them.

[0052] The temperature during the heat preservation stage is 400~900 ℃, specifically 400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃, 900 ℃ or any value between them; the heat preservation time during the heat preservation stage is 0~5 h, specifically 0.1 h, 1 h, 2 h, 3 h, 4 h, 5 h or any value between them.

[0053] In some embodiments, the inert atmosphere environment contains not only inert gases such as nitrogen, argon, neon, and helium, but also reducing gases, such as H2. In this embodiment, during the sintering and fixing of the first shell 110 and the capillary structure 130 / liquid wick 131 in the inert atmosphere environment, the reducing gas can reduce the metal oxides on the surface of the capillary structure 130 / liquid wick 131, which helps to reduce the interfacial thermal resistance of the capillary structure 130 / liquid wick 131 and improve the heat transfer performance of the heat spreader 100.

[0054] S30. A hydrophilic layer is provided on the surface of the capillary structure 130.

[0055] In some embodiments, the hydrophilic layer comprises at least one material selected from silicon dioxide, titanium dioxide, aluminum oxide, and silicon oxynitride. Of course, those skilled in the art may also select other materials according to actual conditions. The water contact angle of the hydrophilic layer is ≤30°. Within this range, it is beneficial to significantly accelerate the gas-liquid circulation of the working fluid within the heat spreader 100, thereby improving the heat dissipation effect of the heat spreader 100. The thickness of the hydrophilic layer is 100~400 nm, specifically 100 nm, 250 nm, 400 nm, or any value between them.

[0056] In this application embodiment, there are various methods for setting the hydrophilic layer, including film application and deposition. Specifically, these methods can be chemical vapor deposition (PECVD) or magnetron sputtering (PVD). PECVD utilizes the glow discharge phenomenon; under the influence of an electric field, the gas in the deposition chamber is ionized into plasma. Active particles collide with the surface of the capillary structure 130, triggering a chemical reaction and depositing a thin film. PVD, in a vacuum environment, uses a magnetic field to confine high-energy plasma, bombarding the target surface to sputter target atoms / ions. These particles then deposit on the surface of the capillary structure 130, forming a uniform and dense thin film. Of course, other common film deposition methods can also be used, and those skilled in the art can choose flexibly according to the actual situation.

[0057] In some embodiments, a hydrophilic layer is formed on the surface of the capillary structure 130 using chemical vapor deposition, wherein the precursor gas used in the hydrophilic layer deposition process includes tetraethyl orthosilicate (TEOS, C8H). 20 O4Si), tetramethylsilane (TMS, Si(CH3)4), hexamethyldisiloxane (HMDSO, C6H 18 OSi2), titanium tetrachloride (TiCl4), titanium isopropoxide (TTIP, C 12 H 28 O4Ti), tetrakis(dimethylamino)titanium (TDMAT, C8H) 24 At least one of N4Ti; the reaction gas used includes at least one of oxygen (O2), nitrous oxide (N2O), and ammonia (NH3).

[0058] In some embodiments, the specific steps of forming a hydrophilic layer on the surface of the capillary structure 130 using chemical vapor deposition include: A chemical vapor deposition apparatus is provided, which has a first deposition chamber. A capillary structure 130 (fixed on a first housing 110) is placed in the first deposition chamber, and the first deposition chamber is evacuated to a first preset pressure. The capillary structure 130 was subjected to plasma bombardment cleaning. After plasma bombardment cleaning, a first mixed gas of precursor gas and reactive gas is introduced into the first deposition chamber to perform a first deposition coating treatment on the capillary structure 130, and then cooled to room temperature.

[0059] In some embodiments, the first preset pressure is 10~20 mTorr, specifically 10 mTorr, 15 mTorr, 20 mTorr, or any value between them. The bombardment gas for the first plasma bombardment cleaning includes Ar and N2O in a volume ratio of 1:(1~1.7), specifically 1:1, 1:1.4, 1:1.7, or any value between them. The total flow rate of the bombardment gas for the first plasma bombardment cleaning is 50~100 sccm, specifically 50 sccm, 70 sccm, 90 sccm, 100 sccm, or any value between them. The radio frequency power for the first plasma bombardment cleaning is 100~200 W, specifically 100 W, 130 W, 160 W, 200 W, or any value between them. The pressure for the first plasma bombardment cleaning is 55~60 mTorr, specifically 55 mTorr, 58 mTorr, 60 mTorr, or any value between them. The duration of the first plasma bombardment cleaning is 10-15 min, specifically 10 min, 13 min, 15 min, or any value between them. The temperature of the first deposition chamber during the first plasma bombardment cleaning is 23-27 ℃, specifically 23 ℃, 25 ℃, 27 ℃, or any value between them.

[0060] In some embodiments, the volume ratio of the precursor gas to the reactant gas is (12~14):1, specifically 12:1, 13:1, 14:1, or any value between them. The total flow rate of the first mixed gas is 200~300 sccm, specifically 200 sccm, 250 sccm, 300 sccm, or any value between them. The RF power of the first deposition coating process is 300~370 W, specifically 300 W, 340 W, 370 W, or any value between them. The duration of the first deposition coating process is 35~40 min, specifically 35 min, 38 min, 40 min, or any value between them. The pressure of the first deposition coating process is 80~85 mTorr, specifically 80 mTorr, 83 mTorr, 85 mTorr, or any value between them. The temperature of the first deposition chamber in the first deposition coating process is 26~30 °C, specifically 26 °C, 28 °C, 30 °C, or any value between them. The temperature of the substrate (capillary structure 130) for the first deposition coating treatment is 38~42 ℃, specifically 38 ℃, 40 ℃, 42 ℃ or any value between them.

[0061] In some embodiments, during the process of depositing a hydrophilic layer on the surface of the capillary structure 130 using chemical vapor deposition, after the first deposition coating treatment, the method further includes a step of subjecting the first deposition coating product to a first annealing treatment. This can increase the adhesion between the hydrophilic layer and the substrate (capillary structure 130).

[0062] In some embodiments, the temperature of the first annealing treatment is 120~160 °C, specifically 120 °C, 130 °C, 140 °C, 150 °C, 160 °C or any value between them. The duration of the first annealing treatment is 0.8~1.2 h, specifically 0.8 h, 0.9 h, 1 h, 1.1 h, 1.2 h or any value between them.

[0063] In PECVD deposition, radio frequency (RF) power determines plasma intensity, film density, and stress; the types and flow rates of precursor and reactant gases determine film composition, stoichiometry, and key photoelectric properties; pressure within the deposition chamber affects particle collisions, deposition rate, uniformity, and step coverage; substrate temperature regulates surface atomic migration, film density, adhesion, and hydrogen content; and electrode spacing, RF frequency, and deposition time affect plasma distribution, ion bombardment energy, and film thickness, respectively. These parameters are interconnected and jointly determine the film deposition rate, structure, stress, uniformity, and overall quality. When using PECVD to deposit hydrophilic layers, controlling the relevant process parameters within the above-mentioned ranges is beneficial for obtaining uniform, dense, and high-quality hydrophilic films.

[0064] In some embodiments, a hydrophilic layer is formed on the surface of the capillary structure 130 using magnetron sputtering. The sputtering target (referred to as the first sputtering target) used in the deposition of the hydrophilic layer is selected from any one of titanium dioxide ceramic target, pure titanium metal target, aluminum oxide ceramic target, pure aluminum metal target, silicon oxynitride ceramic target, and single crystal silicon target. The reaction gas used includes at least one of oxygen and nitrogen.

[0065] In some embodiments, the specific steps of forming a hydrophilic layer on the surface of the capillary structure 130 using magnetron sputtering include: A physical vapor deposition apparatus is provided, which has a second deposition chamber. The capillary structure 130 is placed in the second deposition chamber, and the second deposition chamber is evacuated to a second preset pressure. The capillary structure 130 was subjected to a second plasma bombardment cleaning. After the second plasma bombardment cleaning, a second mixed gas of the first sputtering gas and the reactive gas is introduced into the second deposition chamber. The first sputtering target is selected to perform a second deposition coating on the capillary structure 130, and then the chamber is cooled to room temperature.

[0066] In some embodiments, the second preset pressure is 5 × 10 -4 ~6×10 -4 Pa, specifically 5 × 10 -4 Pa, 5.5 × 10 -4 Pa, 6×10 -4 Pa or any value between them. The bombardment gas for the second plasma bombardment cleaning is argon. The total flow rate of the bombardment gas for the second plasma bombardment cleaning is 60~80 sccm, specifically 60 sccm, 70 sccm, 80 sccm or any value between them. The radio frequency power for the second plasma bombardment cleaning is 150~220 W, specifically 150 W, 180 W, 220 W or any value between them. The temperature of the second deposition chamber during the second plasma bombardment cleaning is 22~27 ℃, specifically 22 ℃, 25 ℃, 27 ℃ or any value between them. The duration of the second plasma bombardment cleaning is 8~15 min, specifically 8 min, 10 min, 15 min or any value between them.

[0067] In some embodiments, the volume ratio of the first sputtering gas to the reactant gas is (4-5):1, specifically 4:1, 4.5:1, 5:1, or any value between them. The first sputtering gas includes argon. The total flow rate of the second mixed gas is 100-200 sccm, specifically 100 sccm, 150 sccm, 200 m sccm, or any value between them. The sputtering power of the second deposition process is 200-270 W, specifically 220 W, 250 W, 270 W, or any value between them. The duration of the second deposition process is 67-75 min, specifically 67 min, 70 min, 75 min, or any value between them. The deposition rate of the second deposition process is 1.5-2 nm / min, specifically 1.5 nm / min, 1.8 nm / min, 2 nm / min, or any value between them. The temperature of the second deposition chamber in the second deposition coating process is 26~30 ℃, specifically 26 ℃, 28 ℃, 30 ℃ or any value between them. The temperature of the substrate (capillary structure 130) in the second deposition coating process is 38~42 ℃, specifically 38 ℃, 40 ℃, 42 ℃ or any value between them.

[0068] In some embodiments, during the deposition of a hydrophilic layer on the surface of the capillary structure 130 using magnetron sputtering, after the second deposition coating process, the method further includes a step of subjecting the second deposition coating product to a second annealing treatment. This can increase the adhesion between the hydrophilic layer and the substrate (capillary structure 130).

[0069] In some embodiments, the temperature of the second annealing treatment is 120~160 °C, specifically 120 °C, 130 °C, 140 °C, 150 °C, 160 °C or any value between them. The duration of the second annealing treatment is 0.8~1.2 h, specifically 0.8 h, 0.9 h, 1 h, 1.1 h, 1.2 h or any value between them.

[0070] In magnetron sputtering deposition, sputtering power determines the sputtering rate and particle energy, affecting film density and adhesion; operating pressure affects particle scattering, deposition rate, and film stress; substrate temperature affects atomic migration, crystallinity, and internal stress; and the ratio of sputtering gas to reactive gas directly controls the composition and stoichiometry of the reactive sputtered film. These parameters are interdependent and jointly determine the deposition rate, density, uniformity, adhesion, stress, microstructure, and overall performance of the thin film. When using magnetron sputtering to deposit a hydrophilic layer, controlling the relevant process parameters within the above-mentioned ranges is beneficial for obtaining a uniform, dense, high-quality hydrophilic film.

[0071] S40. Provide a second housing 120, and provide a hydrophobic layer on the inner wall surface of the second housing 120.

[0072] In this embodiment, a hydrophobic layer can be provided on the entire inner wall surface of the second housing 120, or a hydrophobic layer can be provided at a local location on the inner wall surface of the second housing 120. Those skilled in the art can make adjustments according to the actual situation.

[0073] In some embodiments, the hydrophobic layer includes fluorine-doped titanium dioxide (TiO2:F) and carbon fluoride (CF2). x At least one material selected from polysiloxane (organosilicon). In some embodiments, the fluorine doping content in fluorine-doped titanium dioxide (TiO2:F) is 1.0 to 2.5 at% (atomic percentage), specifically 1 at%, 1.5 at%, 2 at%, 2.5 at%, or any value between them.

[0074] Fluorine content is a core parameter determining hydrophobic properties. Introducing an appropriate amount of fluorine atoms can replace hydroxyl (-OH) and hydrogen atoms in the film layer, reducing surface energy, significantly increasing the water contact angle, and enhancing hydrophobicity and self-cleaning ability. Simultaneously, the introduction of fluorine can reduce the film's refractive index, increase density, reduce defects, and improve insulation and corrosion resistance. When the fluorine content is too low, there are insufficient low-surface-energy fluorine groups on the film surface, which cannot effectively replace the surface hydroxyl (-OH) groups, leading to poor hydrophobicity, a low water contact angle, and easy water absorption and fouling of the film. At the same time, the improvement in film density and defects is not significant, and weather resistance, corrosion resistance, and insulation are also difficult to achieve ideal levels. Overall, the hydrophobic effect is weak, stability is poor, and the functional advantages of fluorine-doped hydrophobic layers cannot be fully utilized. When the fluorine content is too high, it leads to increased internal stress and a loose structure in the film layer, resulting in problems such as decreased adhesion, easy cracking, reduced deposition rate, and poor uniformity. Furthermore, excessive fluorine enrichment may cause abnormal surface roughness, which in turn weakens hydrophobic stability. Therefore, only by controlling the appropriate fluorine content can the optimal balance be achieved between hydrophobicity, structural density, adhesion and mechanical stability.

[0075] In some embodiments, the thickness of the hydrophobic layer is 100~400 nm, specifically 100 nm, 250 nm, 400 nm, or any value between them. The water contact angle on the surface of the hydrophobic layer is ≥110°. Within this range, it is beneficial to significantly accelerate the gas-liquid circulation of the working fluid within the heat spreader 100, thereby improving the heat dissipation effect of the heat spreader 100.

[0076] In the embodiments of this application, there are various methods for setting the hydrophobic layer. It can be set by film application or by coating. Specifically, it can be set by chemical vapor deposition (PECVD), magnetron sputtering (PVD) or other common film deposition methods. Those skilled in the art can choose flexibly according to the actual situation.

[0077] In some embodiments, a hydrophobic layer is formed on the inner wall surface of the second housing 120 using chemical vapor deposition. The precursor gas used in the hydrophobic layer deposition process includes a titanium-containing precursor and / or a fluorine-containing precursor. The titanium-containing precursor includes at least one of titanium tetrachloride, titanium isopropoxide, and tetra(dimethylamino)titanium. The fluorine-containing precursor includes at least one of carbon tetrafluoride, sulfur hexafluoride, trifluoromethane, hexafluoroethane, and perfluorobutane. The reaction gas used includes at least one of oxygen, nitrous oxide, argon, and nitrogen. The specific steps for forming the hydrophobic layer on the inner wall surface of the second housing 120 using chemical vapor deposition include: A chemical vapor deposition apparatus is provided, which has a third deposition chamber. The second housing 120 is placed in the third deposition chamber, and the third deposition chamber is evacuated to a third preset pressure. The inner wall surface of the second housing 120 is subjected to a third plasma bombardment cleaning. After the third plasma bombardment cleaning, a third mixed gas of precursor gas and reactive gas is introduced into the third deposition chamber to perform a third deposition coating treatment on the inner wall surface of the second shell 120, and then cooled to room temperature.

[0078] In some embodiments, the third preset pressure is 10-15 mTorr, specifically 10 mTorr, 12 mTorr, 15 mTorr, or any value between them. The bombardment gas for the third plasma bombardment cleaning includes argon and nitrous oxide in a volume ratio of 1:(1-2), specifically a volume ratio of 1:1, 1:1.5, 1:2, or any value between them. The total flow rate of the bombardment gas for the third plasma bombardment cleaning is 100-200 sccm, specifically 100 sccm, 130 sccm, 160 sccm, 200 sccm, or any value between them. The radio frequency power for the third plasma bombardment cleaning is 100-150 W, specifically 100 W, 130 W, 150 W, or any value between them. The pressure for the third plasma bombardment cleaning is 60-75 mTorr, specifically 60 mTorr, 70 mTorr, 75 mTorr, or any value between them. The temperature of the third deposition chamber in the third plasma bombardment cleaning is 23~27 ℃, specifically 23 ℃, 25 ℃, 27 ℃ or any value between them. The duration of the third plasma bombardment cleaning is 8~15 min, specifically 8 min, 10 min, 15 min or any value between them.

[0079] In some embodiments, the volume ratio of the titanium-containing precursor gas, the fluorine-containing precursor, and the reactant gas is 1:1:15 to 1:1:2.2, specifically 1:1:15, 1:1:10, 1:1:5, 1:1:2.2, or any value between them. The total flow rate of the third mixed gas is 80 to 100 sccm, specifically 80 sccm, 90 sccm, 100 sccm, or any value between them. The RF power of the third deposition coating process is 90 to 120 W, specifically 90 W, 100 W, 120 W, or any value between them. The duration of the third deposition coating process is 30 to 45 min, specifically 30 min, 38 min, 45 min, or any value between them. The pressure of the third deposition coating process is 35 to 40 mTorr, specifically 35 mTorr, 38 mTorr, 40 mTorr, or any value between them. The temperature of the third deposition chamber in the third deposition coating process is 24~27 ℃, specifically 24 ℃, 25 ℃, 27 ℃ or any value between them. The temperature of the substrate (second shell 120) in the third deposition coating process is 38~42 ℃, specifically 38 ℃, 40 ℃, 42 ℃ or any value between them.

[0080] In some embodiments, during the deposition of a hydrophobic layer on the inner wall surface of the second housing 120 using chemical vapor deposition, after the third deposition coating treatment, the process further includes a step of subjecting the third deposition coating product to a third annealing treatment. This increases the adhesion between the hydrophobic layer and the substrate (second housing 120). The temperature of the third annealing treatment is 120~160℃, specifically 120℃, 130℃, 140℃, 150℃, 160℃ or any value between them. The duration of the third annealing treatment is 0.8~1.2 h, specifically 0.8 h, 0.9 h, 1 h, 1.1 h, 1.2 h or any value between them.

[0081] During the process of depositing a hydrophobic layer on the inner wall surface of the second housing 120 using chemical vapor deposition, controlling the relevant process parameters within the above-mentioned range is beneficial to forming a uniform, firm, and moderately thick hydrophobic coating.

[0082] In some embodiments, a hydrophobic layer is formed on the inner wall surface of the second housing 120 using magnetron sputtering. The sputtering target (referred to as the second sputtering target) used in the deposition of the hydrophobic layer is selected from any one of the following: fluorine-doped titanium dioxide ceramic target, composite target of titanium dioxide ceramic target and magnesium fluoride ceramic target, titanium fluoride ceramic target, polytetrafluoroethylene polymer target, organosilicon ceramic target, and siloxane composite target. The reaction gas used includes at least one of oxygen, carbon tetrafluoride, and nitrogen.

[0083] In some embodiments, the fluorine doping content of the composite target of titanium dioxide ceramic target and magnesium fluoride ceramic target is 1.0~2.5 at%, specifically 1.0 at%, 1.5 at%, 2.0 at%, 2.5 at%, or any value between them.

[0084] In some embodiments, the specific steps of forming a hydrophobic layer on the inner wall surface of the second housing 120 using magnetron sputtering include: A physical vapor deposition apparatus is provided, which has a fourth deposition chamber. The second housing 120 is placed in the fourth deposition chamber, and the fourth deposition chamber is evacuated to a fourth preset pressure. The inner wall surface of the second housing 120 is subjected to a fourth plasma bombardment cleaning. After the fourth plasma bombardment cleaning, a fourth mixed gas of the second sputtering gas and the reaction gas is introduced into the fourth deposition chamber. The second sputtering target is selected to perform the fourth deposition coating treatment on the inner wall surface of the second shell 120, and then cooled to room temperature.

[0085] In some embodiments, the fourth preset pressure is 5 × 10 -4 ~6×10 -4 Pa, specifically 5 × 10 -4 Pa, 5.5 × 10 -4 Pa, 6×10 -4 Pa or any value between them. The bombardment gas for the fourth plasma bombardment cleaning is argon. The total flow rate of the bombardment gas for the fourth plasma bombardment cleaning is 80~100 sccm, specifically 80 sccm, 90 sccm, 100 mSccm or any value between them. The radio frequency power for the fourth plasma bombardment cleaning is 150~220 W, specifically 150 W, 180 W, 220 W or any value between them. The temperature of the fourth deposition chamber in the fourth plasma bombardment cleaning is 23~27℃, specifically 23℃, 25℃, 27℃ or any value between them. The duration of the fourth plasma bombardment cleaning is 8~15 min, specifically 8 min, 10 min, 15 min or any value between them.

[0086] In some embodiments, the reaction gas includes O2 and CF4 in a volume ratio of 1:2 to 1:3, specifically 1:2, 1:2.5, 1:3, or any value between them. The total flow rate of the fourth mixed gas is 90 to 120 sccm, specifically 90 sccm, 100 sccm, 120 sccm, or any value between them. The sputtering power of the fourth deposition process is 150 to 220 W, specifically 150 W, 180 W, 220 W, or any value between them. The deposition rate of the fourth deposition process is 1 to 2 nm / min, specifically 1 nm / min, 1.5 nm / min, 2 nm / min, or any value between them. The temperature of the fourth deposition chamber in the fourth deposition process is 24 to 28 °C, specifically 24 °C, 26 °C, 28 °C, or any value between them. The temperature of the substrate (second shell 120) for the fourth deposition coating treatment is 38~42 ℃, specifically 38 ℃, 40 ℃, 42 ℃ or any value between them.

[0087] During the process of depositing a hydrophobic layer on the inner wall of the second housing 120 using magnetron sputtering, controlling the relevant process parameters within the above-mentioned range is beneficial to forming a uniform, firm, and moderately thick hydrophobic coating.

[0088] It should be noted that when both hydrophilic and hydrophobic layers are deposited using chemical vapor deposition, the first and third deposition chambers can be the same deposition chamber of the same chemical vapor deposition equipment; when both hydrophilic and hydrophobic layers are deposited using magnetron sputtering, the second and fourth deposition chambers can be the same deposition chamber of the same physical vapor deposition equipment.

[0089] S50. The first housing 110 and the second housing 120 are fixed to form a cavity 102, and the capillary structure 130 is located in the cavity 102 between the first housing 110 and the second housing 120.

[0090] In some embodiments, the material used to make the second housing 120 may be any one or more of copper alloy, stainless steel, steel-copper alloy, or other materials commonly used in the art.

[0091] In some embodiments, the thickness of the second housing 120 is 0.05 to 5 mm, specifically 0.05 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or any value between them. Provided that the hardness and weight of the second housing 120 meet product requirements, the heat spreader 100 does not break or leak during the manufacturing process, and the overall product weight meets customer requirements, the second housing 120 can be as thin and light as possible.

[0092] In some embodiments, the fixing method of the first housing 110 and the second housing 120 can be selected from any one of laser welding, diffusion welding, brazing, etc.

[0093] In some embodiments, a plurality of support columns 121 protrude from the inner wall surface of the second housing 120. After the first housing 110 is fixed to the second housing 120, the end of the support column 121 away from the second housing 120 abuts against the capillary structure 130 or the first housing 110. On the one hand, the provision of the support column 121 can improve the structural strength of the uniform plate; on the other hand, the provision of the support column 121 can make the capillary structure 130 more stably fixed to the inner wall surface of the first housing 110. The support column 121 can be cylindrical, conical, or other shapes, and those skilled in the art can design it according to actual application requirements.

[0094] In some embodiments, the connection surface between the support column 121 and the second housing 120 is arc-shaped. The arc-shaped transition structure does not disrupt the grain continuity of the second housing 120 and can maintain the high thermal conductivity of the alloy, while avoiding local heat accumulation problems caused by connection defects.

[0095] In the above embodiments, the height of the support column 121 is adaptively adjusted according to the size of the heat spreader 100 or the cavity 102 inside it.

[0096] In some embodiments, the extension length of the support column 121 from the inner wall of the second housing 120 toward the direction opposite to the second housing 120 is 0.05~5 mm. Under the condition of meeting the total thickness requirement of the heat spreader 100, the longer the extension length, the better. The longer the extension length, the larger the space of the inner cavity 102 of the heat spreader 100, the larger the space for working fluid circulation, and the smaller the flow resistance.

[0097] In some embodiments, a first injection groove 101 is provided on one side of the first housing 110, and a second injection groove 101 is provided on one side of the second housing 120. After the first housing 110 and the second housing 120 are fixed, the first injection groove 101 and the second injection groove 101 are arranged opposite to each other and spliced ​​to form an injection pipe for injecting working fluid into the cavity 102 within the heat spreader 100. The first injection groove 101 and the second injection groove 101 can be semi-circular, rectangular, or other irregular in shape, and those skilled in the art can make adjustments according to the actual situation. The length of the injection pipe is 5 to 100 mm, specifically 5 mm, 15 mm, 30 mm, 50 mm, 80 mm, 100 mm, or any value between them. The diameter of the injection pipe is 1 to 10 mm, specifically 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, or any value between them. By limiting the length and diameter of the injection tube to an appropriate range, it is easier to control the time for injecting working fluid into the cavity 102 within the heat spreader 100 and for evacuating the vacuum during the tube control process.

[0098] S60. A liquid working medium is injected into the cavity 102 formed by the first shell 110 and the second shell 120, and then the cavity is sealed after evacuation to obtain a heat spreader 100.

[0099] In some embodiments, the liquid working medium may include at least one of deionized water, ethanol, or acetone.

[0100] In some embodiments, the amount of liquid working fluid injected is 60% to 100% of the volume of the internal cavity 102 of the heat spreader 100, specifically 60%, 70%, 80%, 90%, 100%, or any value between them. Within this range, it is beneficial to improve the heat dissipation effect of the heat spreader 100.

[0101] In some embodiments, the vacuuming process can be repeated multiple times. Repeated vacuuming reduces residual gas, which helps ensure long-term stability during use.

[0102] Secondly, embodiments of this application also provide a heat spreader 100, which can be manufactured using the manufacturing method of the first aspect.

[0103] Please see Figures 2-10 In this embodiment of the application, the heat spreader 100 includes a shell and a capillary structure 130; wherein, the shell includes a first shell 110 and a second shell 120, and the first shell 110 and the second shell 120 enclose a cavity 102; the capillary structure 130 is disposed in the cavity 102 and fixed to the side of the first shell 110 facing the second shell 120, and the capillary structure 130 includes at least one liquid-absorbing core 131; a hydrophilic layer is disposed on the capillary structure 130, and a hydrophobic layer is disposed on the inner wall surface of the second shell 120.

[0104] Since the heat spreader 100 of this embodiment can be manufactured using the manufacturing method of the first aspect, the specific structure of the heat spreader 100 can refer to the structure of the heat spreader 100 manufactured using the manufacturing method of the first aspect. Since the heat spreader 100 adopts all the technical solutions of the heat spreader 100 in all the above embodiments, it has at least all the beneficial effects brought about by the heat spreader 100 in the above embodiments, which will not be elaborated upon here.

[0105] Thirdly, this application also proposes an electronic device, which includes a heat spreader 100. The manufacturing method and specific structure of the heat spreader 100 are as described in the above embodiments. Since this electronic device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0106] The following provides more detailed embodiments to illustrate the effects of the heat spreader 100 and its manufacturing method of this application.

[0107] Example 1 1. Preparation of raw materials and equipment The heat spreader substrate: the upper cover plate (second shell, the same below) and the lower cover plate (first shell, the same below) are made of H62 brass (copper-zinc alloy), and the capillary structure is made of Cu-ETP oxygen-free copper wire; Capillary structure (metal mesh) parameters: copper wire diameter 0.05 mm, mesh count 200, thickness after weaving 0.12 mm, porosity 70%; Tooling and equipment: PECVD coating machine, vacuum sintering furnace, laser welding machine, two-stage vacuum pump, deionized water preparation device.

[0108] Precursor for coating (PECVD process): Hydrophilic layer: titanium tetrachloride (TiCl4, purity ≥99.99%), oxygen (O2, purity ≥99.99%), argon (Ar, purity ≥99.999%). Hydrophobic layer: titanium tetrachloride (TiCl4, purity ≥99.99%), oxygen (O2, purity ≥99.99%), carbon tetrafluoride (CF4, purity ≥99.99%), argon (Ar).

[0109] 2. Preparation steps (1) Preparation and modification of capillary structure (single-layer metal mesh / liquid absorbent core) Capillary structure attachment: The single-layer copper mesh capillary structure, cut to the target size, is flatly attached to the preset area on the surface of the lower cover plate; Sintering process: The lower cover plate with the attached capillary structure is placed in a vacuum sintering furnace, and a N2 / H2 mixed gas (volume ratio 9:1) is introduced. The temperature is raised to 750 ℃ ​​at a rate of 50 ℃ / min, held for 3 h, and then allowed to cool naturally to room temperature to complete the sintering and fixing of the capillary structure and the lower cover plate.

[0110] PECVD coating modification: Vacuuming: Place the sintered lower cover plate (containing capillary structure) into the PECVD deposition chamber and evacuate to 10 mTorr; Plasma bombardment cleaning: Set the radio frequency power to 100 W, introduce a mixed gas of Ar:N2O=1:1 (volume ratio), gas flow rate of 100 sccm, maintain furnace pressure at 60 mTorr, chamber temperature at 25 ℃, and clean for 10 min. Precipitation coating: Adjust the RF power to 300 W, introduce the precursor mixed gas of TiCl4:O2=1:14 (volume ratio), the total flow rate is 200 sccm, the furnace pressure is 80 mTorr, the chamber temperature is 28 ℃, the substrate temperature is 40 ℃, and the coating is carried out for 35 min to form a 50 nm thick TiO2 hydrophilic layer. Cooling and sampling: Turn off the RF power supply and precursor gas, introduce argon gas (flow rate 80 sccm), and after the chamber cools naturally to room temperature, slowly depressurize to atmospheric pressure and remove the sample.

[0111] (3) Coating modification of the top cover plate a. Pretreatment of the top cover plate: The top cover plate (2.6mm thick, with a cylindrical support column in the middle recessed area, the support column height is 1mm) is ultrasonically degreased, acid-washed and activated, and then dried for later use.

[0112] b. PECVD coating: Vacuuming: Place the pretreated top cover plate into the PECVD deposition chamber and evacuate to 10 mTorr; Plasma bombardment cleaning: Set the radio frequency power to 100 W, introduce a mixed gas of Ar:N2O=1:1 (volume ratio), gas flow rate of 100 sccm, maintain furnace pressure at 60 mTorr, chamber temperature at 25 ℃, and clean for 10 min. Precipitation coating: Set the RF power to 90 W, introduce a precursor gas mixture of TiCl4:O2:CF4 = 1:1:15 (volume ratio), with a total flow rate of 80 sccm, furnace pressure of 35 mTorr, chamber temperature of 26 ℃, substrate temperature of 40 ℃, and coating for 30 min to form a 200 nm thick TiO2:F hydrophobic layer; Cooling and sampling: Turn off the power and gas, introduce argon gas (flow rate 60 sccm), cool to room temperature, and then depressurize and take out the sample.

[0113] (4) Welding of upper and lower cover plates Assembly: Align and fit the coated upper cover plate and lower cover plate (including capillary structure) together to ensure that there is no interference between the support column and the capillary structure area of ​​the lower cover plate. The first injection tank and the second injection tank are spliced ​​together to form a complete injection tube (20mm in length and 3mm in diameter). Laser welding: A fiber laser welding machine with a welding power of 1500 W and a welding speed of 3 mm / s is used to seal the edges of the upper and lower cover plates to form a closed cavity.

[0114] (5) Liquid injection and sealing tube Liquid injection: Deionized water (working fluid) is injected into the cavity through the injection tube, with the injection volume being 60% of the cavity volume; First vacuuming: Start the two-stage vacuum pump to evacuate the chamber to a vacuum level of 5 × 10⁻⁶. -3 Pa, maintain for 15 min; Second vacuuming: The cavity is heated to 60 ℃ and held for 30 min, then the vacuum is continued to 1×10 -4 Pa; Tube sealing process: Laser welding is used to seal the injection tube, and excess injection tube is cut off to complete the fabrication of the heat spreader.

[0115] 3. Product performance testing Antioxidant performance: The product was placed in a high-temperature environment of 300 ℃ for 2 h. After cooling, no oxide layer was formed on the surface of the capillary structure and the capillary pores were not blocked.

[0116] Wetting properties: Water contact angle on capillary surface ≤30°, water contact angle on inner surface of top cover plate ≥110°.

[0117] Heat dissipation performance: 100 W / cm 2 At a given heat flux density, the temperature uniformity of the heat spreader is ≤3℃, and the heat dissipation efficiency is 25% higher than that of products using traditional processes.

[0118] Reliability: After 1000 cycles of thermal cycling (-40~85 ℃), the coating did not peel off and there was no leakage at the weld.

[0119] Example 2 1. Preparation of raw materials and equipment Heat spreader substrate: Same as in Example 1; Capillary structure (2-layer metal mesh) parameters: copper wire diameter 0.025 mm, mesh count 235, single layer braid thickness 0.06 mm, porosity 75%, total thickness after 2 layers are bonded 0.11 mm; Equipment and precursors: Same as in Example 1.

[0120] 2. Preparation steps (1) Capillary structure preparation and modification Metal mesh bonding: Align and overlap the two layers of copper mesh, and then flatly attach them to the preset area on the surface of the lower cover plate; Burning treatment: Same as in Example 1 (N2 / H2 environment, 750 ℃ ​​for 3 h); PECVD coating modification: The parameters are the same as those in Example 1 capillary structure coating, but an annealing treatment (N2 environment, 150 ℃ for 1 h) is added after coating to improve the adhesion of the film layer.

[0121] (2)~(4): Coating of the upper cover plate, welding of the upper and lower cover plates, liquid injection and sealing. Except for the injection tube dimensions of 25 mm in length and 4 mm in diameter, the other corresponding steps and parameters are the same as in Example 1.

[0122] 3. Product performance testing Antioxidant performance: No oxide layer is formed after holding at 300 ℃ for 2 h.

[0123] Wettability: Water contact angle on the surface of the absorbent core ≤28°, water contact angle on the inner surface of the top cover ≥115°.

[0124] Heat dissipation performance: At a heat flux density of 100 W / cm², the temperature uniformity is ≤2.5℃, and the heat dissipation efficiency is 30% higher than that of products made with traditional processes.

[0125] Capillary performance: The capillary climb height is increased by 18% compared to single-layer absorbent core products, and the liquid reflux rate is increased by 22%.

[0126] Example 3 1. Preparation of raw materials and equipment Heat spreader substrate: The upper cover, lower cover, and capillary structure are made of 316 L stainless steel; Capillary structure (single-layer metal mesh) parameters: metal mesh wire diameter 0.05 mm, mesh count 200, thickness 0.12 mm, porosity 70%; Tooling and equipment: PVD (magnetron sputtering) coating machine, vacuum sintering furnace, laser welding machine, two-stage vacuum pump, deionized water preparation device.

[0127] Precursor for coating (PVD process): TiO2 hydrophilic layer: TiO2 ceramic target (purity ≥99.9%), argon (Ar, purity ≥99.999%), oxygen (O2, purity ≥99.99%). TiO2:F hydrophobic layer: TiO2:MgF2 composite ceramic target (fluorine doping 1.5 at%), argon (Ar), oxygen (O2), carbon tetrafluoride (CF4, purity ≥99.99%).

[0128] 2. Preparation steps (1) Capillary structure preparation and PVD coating Capillary attachment and screen burning process: Same as in Example 1.

[0129] PVD (magnetron sputtering) coating modification: Vacuuming: Place the spot-welded lower cover plate (including capillary structure) into the PVD deposition chamber and evacuate to 5×10⁻⁶. - 4 Pa; Plasma cleaning: Set the radio frequency power to 150 W, introduce pure argon gas at a flow rate of 80 sccm, maintain the chamber temperature at 25℃, and clean for 8 min to remove residual impurities from the capillary surface. Sputtering coating: TiO2 ceramic target was used, sputtering power was 200 W, volume ratio of sputtering gas Ar to reactive gas O2 was 4:1, total flow rate was 100 sccm, substrate temperature was 40 ℃, deposition rate was 1.5 nm / min, continuous coating was carried out for 67 min, forming a 100 nm thick TiO2 hydrophilic layer. Cooling and sampling: Turn off the target power and reaction gas, introduce argon gas (flow rate 100 sccm), allow it to cool naturally to room temperature, then depressurize and take out the sample.

[0130] (2) PVD coating on the top cover plate Top cover pretreatment: Same as in Example 1.

[0131] PVD (magnetron sputtering) coating: Vacuuming: Place the pre-treated top cover plate into the PVD chamber and evacuate to 5×10⁻⁶. -4 Pa; Plasma cleaning: RF power 150 W, argon flow rate 80 sccm, temperature 25 ℃, duration 8 min (parameters consistent with capillary cleaning). Sputtering coating: TiO2:MgF2 composite ceramic target, sputtering power 150 W, volume ratio of sputtering gas Ar, reactive gas O2 and CF4 5:1:2, total flow rate 90 sccm, substrate temperature 40 ℃, deposition rate 1 nm / min, continuous coating for 400 min, forming a 400 nm thick TiO2:F hydrophobic layer; Cooling and sampling: Turn off the power and gas, introduce argon gas (flow rate 80 sccm), cool to room temperature, and then depressurize and take out the sample.

[0132] (3)~(4): Welding, liquid injection and sealing of pipes Except for the injection tube length being 30 mm and the diameter being 3 mm, the other corresponding steps and parameters are the same as in Example 1.

[0133] 3. Product performance testing Antioxidant performance: No oxide layer is formed after holding at 350 ℃ for 2 h.

[0134] Wettability: Water contact angle on the surface of the absorbent core ≤25°, water contact angle on the inner surface of the top cover ≥120°.

[0135] Abrasion resistance: After 50 friction tests (load 5 N), the coating showed no damage or peeling.

[0136] Heat dissipation performance: At a heat flux density of 100 W / cm², the temperature uniformity of the heat spreader is ≤2.8 ℃, and the heat dissipation efficiency is 28% higher than that of products using traditional processes.

[0137] Example 4 1. Preparation of raw materials and equipment Heat spreader substrate: Same as in Example 3; Capillary structure (2-layer metal mesh) parameters: consistent with Example 2; Equipment and precursors: Same as in Example 3.

[0138] 2. Preparation steps (1) Preparation of double-layer wick and PVD coating (deposition of 100 nm TiO2 film) The steps for attaching and spot welding the absorbent core are the same as those in Example 2.

[0139] PVD (magnetron sputtering) coating modification: The parameters are the same as the corresponding steps in Example 3.

[0140] (2) PVD coating of the top cover plate: the same as the corresponding steps in Example 3.

[0141] (3)~(4): Welding, liquid injection and sealing of pipes Except for the injection tube length of 28 mm and diameter of 4 mm, the other parameters of the corresponding steps are the same as in Example 1.

[0142] 3. Product performance testing Antioxidant performance: No oxide layer is formed after holding at 350 ℃ for 2 h.

[0143] Wettability: Water contact angle on the surface of the absorbent core ≤23°, water contact angle on the inner surface of the top cover ≥125°.

[0144] Heat dissipation performance: 100 W / cm 2 At the heat flux density, the temperature uniformity is ≤2.2 ℃, and the heat dissipation efficiency is 35% higher than that of products made with traditional processes.

[0145] Long-term stability: After being placed in an environment of 85 ℃ and 85% relative humidity for 1000 h, there is no performance degradation, the coating is firmly bonded to the substrate, and there is no peeling.

[0146] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a heat spreader, characterized in that, Includes the following steps: A metal mesh is provided, and the metal mesh is cut to the desired size to obtain a liquid-absorbing core; A first housing is provided, and at least one layer of the liquid-absorbing core is fixed to the inner wall surface of the first housing, wherein the at least one layer of the liquid-absorbing core forms a capillary structure; A hydrophilic layer is provided on the surface of the capillary structure; A second housing is provided, and a hydrophobic layer is provided on the inner wall surface of the second housing; The first housing and the second housing are fixed to form a cavity, and the capillary structure is located in the cavity between the first housing and the second housing; A working fluid is injected into the cavity formed by the first shell and the second shell, and after evacuation, it is sealed to obtain a heat spreader.

2. The manufacturing method as described in claim 1, characterized in that, A hydrophilic layer is deposited on the surface of the capillary structure using chemical vapor deposition. The precursor gas used includes at least one selected from tetraethyl orthosilicate, tetramethylsilane, hexamethyldisiloxane, titanium tetrachloride, titanium isopropoxide, tetra(dimethylamino)titanium, trimethylaluminum, triethylaluminum, and triisopropylaluminum. The reactant gas used includes at least one selected from oxygen, nitrous oxide, and ammonia. Alternatively, A hydrophilic layer is formed on the surface of the capillary structure by magnetron sputtering. The sputtering target is selected from any one of silicon dioxide ceramic target, titanium dioxide ceramic target, pure titanium metal target, aluminum oxide ceramic target, pure aluminum metal target, silicon oxynitride ceramic target, and single crystal silicon target. The reaction gas used includes at least one of oxygen and nitrogen.

3. The manufacturing method as described in claim 1, characterized in that, A hydrophobic layer is formed on the inner wall surface of the second shell using chemical vapor deposition. The precursor gas used includes a titanium-containing precursor and / or a fluorine-containing precursor. The titanium-containing precursor includes at least one of titanium tetrachloride, titanium isopropoxide, and tetra(dimethylamino)titanium. The fluorine-containing precursor includes at least one of carbon tetrafluoride, sulfur hexafluoride, trifluoromethane, hexafluoroethane, and perfluorobutane. The reaction gas used includes at least one of oxygen, nitrous oxide, argon, and nitrogen. Alternatively, A hydrophobic layer is formed on the inner wall surface of the second shell using magnetron sputtering. The sputtering target is selected from any one of the following: fluorine-doped titanium dioxide ceramic target, composite target of titanium dioxide ceramic target and magnesium fluoride ceramic target, titanium fluoride ceramic target, polytetrafluoroethylene polymer target, organosilicon ceramic target, and siloxane composite target. The reaction gas used includes at least one of oxygen, carbon tetrafluoride, and nitrogen.

4. The method for manufacturing a heat spreader as described in claim 1, characterized in that, The hydrophilic layer comprises at least one material selected from silicon oxide, titanium dioxide, aluminum oxide, and silicon oxynitride; and / or, The hydrophobic layer comprises at least one material selected from fluorine-doped titanium dioxide, fluorinated carbon, and polysiloxane.

5. The method for manufacturing a heat spreader as described in claim 4, characterized in that, The fluorine doping content in the fluorine-doped titanium dioxide is 1.0~3.0 at.

6. The manufacturing method as described in claim 1, characterized in that, The liquid-absorbing core is fixed to the inner wall of the first housing in any one of the following methods: sintering in an inert atmosphere, adhesive fixing, or spot welding; and / or, The fixing method of the first housing and the second housing is selected from any one of laser welding, diffusion welding, and brazing.

7. The manufacturing method as described in claim 6, characterized in that, The inert atmosphere contains reducing gases.

8. The manufacturing method as described in claim 1, characterized in that, Includes at least one of the following features: (1) The total thickness of the capillary structure is 0.04~2 mm; (2) The thickness of the metal mesh is 0.04~0.15 mm; (3) The diameter of the wire mesh is 0.005~0.1 mm; (4) The porosity of the metal mesh is 60-95%; (5) The mesh count of the metal mesh is 80~500 mesh.

9. The manufacturing method as described in claim 1, characterized in that, The inner wall of the second housing is provided with a plurality of support columns. After the first housing and the second housing are fixed, the end of the support column away from the second housing abuts against the capillary structure or the first housing.

10. The manufacturing method as described in claim 1, characterized in that, The first housing is provided with a first injection tank, and the second housing is provided with a second injection tank. After the first housing and the second housing are fixed, the first injection tank and the second injection tank are arranged opposite to each other and spliced ​​together to form an injection pipe for injecting working fluid into the heat spreader.

11. The manufacturing method according to any one of claims 1-10, characterized in that, Includes at least one of the following features: (1) The thickness of the hydrophilic layer is 100~400 nm; (2) The thickness of the hydrophobic layer is 100~400 nm; (3) The thickness of the first shell is 0.05~5 mm; (4) The thickness of the second shell is 0.05~5 mm.

12. A heat spreader, characterized in that, include: The housing includes a first housing and a second housing, the first housing and the second housing enclosing a cavity; A capillary structure is disposed in the cavity and fixed to the side of the first housing facing the second housing, the capillary structure comprising at least one liquid-absorbing core; The capillary structure is provided with a hydrophilic layer, and the inner wall surface of the second shell is provided with a hydrophobic layer.

13. An electronic device, characterized in that, Including the heat spreader obtained by the manufacturing method as described in any one of claims 1-11.

Images