Directional wick vapor chamber and preparation method and application thereof

Abstract

The invention relates to a directional wick vapor chamber and a preparation method and application thereof in the technical field of vapor chambers. The preparation method comprises the following steps: preparing a lower substrate and an upper substrate; a directional liquid absorption core structure is printed on one side of the lower base plate through the 3D printing technology, the directional liquid absorption core structure comprises a plurality of liquid absorption core units, and the liquid absorption core units are arranged in an equidistant or unequidistant array mode in the X-axis direction and the Y-axis direction; the side, provided with the directional wick structure, of the lower substrate and the periphery of the upper substrate share the same edge and are sealed and packaged, and a position for containing a liquid injection pipe is reserved and used for liquid injection and degassing; carrying out accurate liquid injection, primary degassing and secondary degassing on the sealed upper substrate and lower substrate; and sealing: cutting off the liquid injection pipe part, and finally packaging the liquid injection pipe part to form the complete directional wick vapor chamber with the directional transmission characteristic. According to the directional wick vapor chamber prepared through the preparation method, the heat flow distribution of the vapor chamber can be improved, and the heat transfer performance is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vapor chambers, and in particular to a directional liquid wick vapor chamber and a preparation method and application thereof. Background Art

[0002] With the rapid development of science and technology, high heat flux density devices such as 5G chips and IGBTs have put forward higher requirements for heat dissipation technology. Thermal diodes are favored by researchers for their excellent high thermal rectification ratio ability, precise control of heat source temperature, and prevention of equipment overheating. At the same time, their unique one-way heat transfer characteristics can effectively prevent heat backflow and protect equipment from damage. However, in the face of the rapid enhancement of the performance of core components of electronic equipment and the trend of equipment towards miniaturization and thinness, the design of thermal diodes in shape and size is limited by the size of the equipment space, and it is mainly one-dimensional linear heat conduction. For electronic equipment with high heat flux density, the heat transfer efficiency is limited.

[0003] In order to overcome these limitations, ultra-thin phase change heat dissipation technology with two-dimensional heat transfer function came into being, providing a more efficient heat dissipation solution. However, the current heat spreader's liquid wick mostly adopts a porous foam metal liquid wick structure or a porous wire mesh liquid wick structure, which is mainly made by sintering. The prepared liquid wick structure and heat spreader are not only thick and heavy, but also have low thermal conductivity efficiency, high thermal resistance, and high energy consumption, which can easily affect the performance of electronic equipment with high heat flux density. Summary of the invention

[0004] In view of the problems existing in the background technology, the present application provides a directional liquid wick vapor chamber and a preparation method and application thereof. The directional liquid wick vapor chamber prepared by the preparation method can improve the heat flow distribution of the vapor chamber and enhance the heat transfer performance.

[0005] According to a first aspect of the present invention, a method for preparing a directional wick heat spreader is provided, comprising the following steps: preparing a lower substrate and an upper substrate; using 3D printing technology to print a directional wick structure on one side of the lower substrate, the directional wick structure comprising a plurality of wick units, and the plurality of wick units are arranged in an array with equal or unequal spacing along the X and Y axis directions; the side of the lower substrate with the directional wick structure is co-edge-jointed with the periphery of the upper substrate and sealed and packaged, and a position for placing a liquid injection tube is reserved for liquid injection and degassing; the sealed upper and lower substrates are accurately injected, degassed once, and degassed twice; sealing and cutting off the liquid injection tube portion, and finally packaging it to form a complete directional wick heat spreader with directional transmission characteristics.

[0006] In some embodiments of the present invention, the wick unit is selected from one or more of a concave angle structure, a convex angle structure, an asymmetric trapezoidal pillar structure, a blade bionic structure, a gradient structure and an optimized gradient structure; wherein

[0007] The concave angle structure is a three-dimensional structure in which a closed plane formed by two parallel arcs extends to a certain height in the Z-axis direction;

[0008] The convex angle structure is a three-dimensional structure formed by extending a closed plane formed by two parallel V-shaped lines to a certain height in the Z-axis direction;

[0009] The asymmetric trapezoidal pillar structure is a three-dimensional structure formed by stretching a trapezoidal plane arranged at an acute angle or a right angle to the lower substrate along a set direction to a certain thickness;

[0010] The blade bionic structure is a three-dimensional structure formed by stretching a blade-shaped closed surface arranged at an acute angle with the lower substrate in the Z-axis direction to a certain thickness;

[0011] The gradient structure is a three-dimensional structure formed by stacking rectangular parallelepiped structures of different or same thickness in the Z-axis direction and displacing them in the X-axis direction or the Y-axis direction;

[0012] The optimized gradient structure is a three-dimensional structure formed by opening a groove of a certain depth from the side close to the lower substrate to the side close to the upper substrate.

[0013] In some embodiments of the present invention, the height of the wick unit in the Z-axis direction is 100 μm-75 mm.

[0014] In some embodiments of the present invention, the thickness of the lower substrate and the upper substrate are independently 0.025-0.075 mm.

[0015] In some embodiments of the present invention, the directional liquid wick vapor chamber is a vapor chamber with gas and liquid coplanarly or a vapor chamber with gas and liquid skewedly arranged in different planes.

[0016] In some embodiments of the present invention, printing a directional wick structure on one side of the lower substrate using 3D printing technology includes the following steps: using ultra-high precision light-curing additive manufacturing technology to integrally print array-arranged wick units on the lower substrate; chemically plating the integrally printed array-arranged wick units; and oxidizing the chemically plated array-arranged wick units.

[0017] In some embodiments of the present invention, printing a directional wick structure on one side of the lower substrate using 3D printing technology includes the following steps: selecting a hydrophilic resin slurry for 3D printing; using ultra-high precision light-curing 3D printing technology to integrate the hydrophilic resin slurry into an array of wick units on the lower substrate.

[0018] In some embodiments of the present invention, the hydrophilic resin slurry is a photosensitive resin slurry or a hydrogel resin slurry to which an emulsifier is added.

[0019] According to a second aspect of the present invention, there is provided a directional liquid absorbent wick vapor chamber prepared by the above-mentioned method for preparing the directional liquid absorbent wick vapor chamber.

[0020] According to a third aspect of the present invention, there is provided a directional wick vapor chamber prepared by the preparation method of the directional wick vapor chamber or the application of the directional wick vapor chamber in heat dissipation of electronic equipment.

[0021] The present invention proposes a method for preparing a high-performance directional liquid-wick heat spreader, which is used to solve the heat dissipation problem in electronic devices with strict requirements on the directional control of heat flow. The present invention can greatly optimize the thermal management performance, improve the heat flow distribution of the heat spreader, and improve the heat transfer performance through six innovative directional liquid-wick structure designs and two preparation methods. It can accurately control the temperature of the heat source with its excellent high thermal rectification ratio capability to prevent the equipment from overheating. At the same time, its unique unidirectional heat transfer characteristics can effectively prevent heat backflow and protect the equipment from damage, which helps to reduce the power consumption of the equipment during operation, thereby extending the battery life of the equipment, improving the overall performance and user experience, and providing a heat spreader that meets specific heat dissipation requirements, providing a customized solution for thermal management of electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0023] Figure 1 It is a side view of the vapor chamber of the gas-liquid coplanar directional liquid wick of the present invention;

[0024] Figure 2 It is a side view of the heat soaking plate of the gas-liquid non-uniform directional liquid absorbing core of the present invention;

[0025] Figure 3 Schematic diagram of the arrangement of the liquid absorbent core unit array of the concave angle structure of the present invention;

[0026] Figure 4Schematic diagram of the arrangement of the liquid absorbent core unit array of the convex corner structure of the present invention;

[0027] Figure 5 Schematic diagram of the arrangement of the liquid absorbent core unit array of the asymmetric trapezoidal pillar structure of the present invention;

[0028] Figure 6 Schematic diagram of the arrangement of the liquid-absorbing core unit array of the bionic leaf structure of the present invention;

[0029] Figure 7 Schematic diagram of the arrangement of the liquid-absorbing core unit array of the gradient structure of the present invention;

[0030] Figure 8 Schematic diagram of the arrangement of the liquid-absorbing core unit array of the optimized gradient structure of the present invention;

[0031] Fig. 9 This is an exploded view of the vapor chamber of the gas-liquid coplanar directional liquid wick of the present invention;

[0032] Fig.10 This is an exploded view of the heat soaking plate of the gas-liquid non-uniform directional liquid absorbing core of the present invention;

[0033] Fig.11 This is a flow chart of the present invention using common 3D printing resin materials to print a directional liquid-absorbing core structure;

[0034] Fig.12 It is a flow chart of the present invention using 3D printing hydrophilic resin slurry to print a directional liquid-absorbing core structure.

[0035] The reference numerals in the accompanying drawings represent the following: 1. lower substrate; 2. directional liquid absorption core structure; 3. gas flow channel; 4. upper substrate; 5. liquid injection tube; 6. support column. DETAILED DESCRIPTION

[0036] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0037] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0038] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0039] A first aspect of the present invention provides a method for preparing a directional liquid wick vapor chamber, the method comprising the following steps:

[0040] (1) Prepare a lower substrate and an upper substrate.

[0041] In the present invention, the lower substrate and the upper substrate are preferably made of an ultra-thin structure with excellent high thermal conductivity, such as Figure 1 and Figure 2 As shown, the prepared oriented liquid wick heat spreader has an upper substrate 4 and a lower substrate 1 that are parallel and spaced apart.

[0042] The materials with excellent high thermal conductivity include but are not limited to metal materials and non-metal materials, and the lower substrate and the upper substrate can be made of the same or different materials.

[0043] The thickness of the lower substrate and the upper substrate in the present invention can be independently 0.025mm-0.075mm; it should be noted that the thickness of the lower substrate and the upper substrate is not particularly limited, and those skilled in the art can make reasonable choices based on actual needs. As some specific examples, the thickness of the lower substrate or the upper substrate can be 0.025mm, 0.035mm, 0.045mm, 0.055mm, 0.065mm, 0.075mm, etc.

[0044] (2) Use 3D printing technology to print a directional liquid-absorbing core structure on one side of the lower substrate.

[0045] In the present invention, if Figure 1 and Figure 2 As shown, the directional wick structure 2 includes a plurality of wick units, which are arranged in an equidistant or unequally spaced array along the X and Y axis directions, and form a gas flow channel 3 for vapor / liquid flow channels, and are used to fill liquid working media.

[0046] It should be noted that the X-axis set in the present invention can be the length (or width) direction of the lower substrate, the Y-axis can be the width (or length) direction of the lower substrate, the X-axis and the Y-axis are perpendicular to each other, and the Z-axis direction can be the thickness direction of the lower substrate.

[0047] In some embodiments of the present invention, the wick unit may be selected from one or more of a concave angle structure, a convex angle structure, an asymmetric trapezoidal pillar structure, a blade bionic structure, a gradient structure, and an optimized gradient structure.

[0048] In the present invention, Figure 3 As shown, the concave angle structure is a three-dimensional structure formed by a closed plane formed by two parallel arcs extending a certain height in the Z-axis direction.

[0049] The concave angle structure is arranged in an array with equal or unequal spacing in the X and Y axis directions to form a directional liquid-absorbing core structure. By optimizing the distribution of the angle, array direction and number of the concave angle structure, the capillary force and permeability are enhanced, a unique liquid flow path can be provided, the liquid absorption performance is optimized, the phase change efficiency and circulation speed of the liquid working fluid are improved, and rapid thermal response and low thermal load startup performance are achieved.

[0050] Furthermore, the angle of the concave angle structure is preferably 30° to 60°. It should be noted that the angle and diameter of the concave angle structure are not particularly limited, and those skilled in the art can make reasonable selections based on actual needs.

[0051] like Figure 4 As shown, the convex angle structure includes but is not limited to a leaf vein bionic structure and a pitcher plant structure. The convex angle structure can specifically be a three-dimensional structure formed by extending a closed plane formed by two parallel V-shaped lines to a certain height in the Z-axis direction.

[0052] The convex angle structure is formed by two line segments forming an angle less than 180° to form a closed plane and extending a certain height in the Z-axis direction. The convex angle structure is arranged in an equidistant or unequally spaced array in the X and Y-axis directions. Similarly, by adjusting the size of the V-shaped angle and the distribution optimization of the array direction and number, the convex angle structure helps the diffusion of the liquid working fluid, avoids local drying and high temperature, enhances the directional transmission of the liquid working fluid, and improves the heat conduction efficiency. It has the advantages of low energy consumption, low flow resistance and high material energy exchange efficiency. Especially under high power conditions, the heat spreader of the convex angle structure exhibits stable thermal resistance and excellent heat transfer performance.

[0053] like Figure 5As shown, the asymmetric trapezoidal pillar structure is a three-dimensional structure formed by stretching a trapezoidal plane arranged at an acute angle or a right angle to the lower substrate to a certain thickness along a set direction, that is, the trapezoidal plane is inclined at a certain angle or arranged vertically on the lower substrate, and the asymmetric trapezoidal pillar structure is obtained by stretching the trapezoidal plane to a certain thickness.

[0054] Preferably, the longer lower bottom of the trapezoidal plane contacts the lower substrate, and one end of the asymmetric trapezoidal pillar structure formed by stretching and facing the lower substrate contacts the surface of the lower substrate.

[0055] By optimizing the shape and layout of the asymmetric trapezoidal pillar structure, the resistance to steam flow can be reduced, and the thickness of the steam chamber can be increased while meeting the size requirements, thereby improving the heat transfer efficiency. The asymmetric design can guide the flow direction of the liquid and enhance heat conduction. In addition, the asymmetric trapezoidal pillar structure helps to diffuse the liquid working medium on the lower substrate and prevent local overheating. It has the advantages of low energy consumption, low flow resistance and high-efficiency material and energy exchange.

[0056] Furthermore, the angle between the trapezoidal plane and the lower substrate is 15° to 90°. It should be noted that the angle between the trapezoidal plane and the lower substrate is not particularly limited. Those skilled in the art can make a reasonable choice based on actual needs. As some specific examples, the angle between the trapezoidal plane and the lower substrate can be 15°, 30°, 45°, 60°, 75°, 90°, etc.

[0057] Furthermore, the thickness of the asymmetric trapezoidal pillar structure is preferably 0.3 mm to 0.5 mm.

[0058] like Figure 6 As shown, the blade bionic structure is a three-dimensional structure formed by stretching a blade-shaped closed plane arranged at an acute angle with the lower substrate in the Z-axis direction to a certain thickness.

[0059] The blade bionic structure adopts a blade bionic design, imitating the fractal structure of plant veins in nature, optimizing the liquid distribution to promote uniform diffusion of liquid working fluid along the capillary core and improve heat dissipation efficiency. Its optimized liquid working fluid transport mode increases the vaporization core and enhances the boiling heat transfer effect. Its polygonal leaf veins serve as a supporting structure, providing numerous reflux channels for the liquid working fluid and realizing gas-liquid separation, thereby ensuring that the heat spreader has excellent heat transfer performance.

[0060] Furthermore, the closed surface of the blade shape may be a plane or an arc-shaped curved surface, that is, the three-dimensional structure formed by stretching the closed surface of the blade shape to a certain thickness may be a flat plate or an arc-shaped plate.

[0061] like Figure 7 As shown, the gradient structure is a three-dimensional structure formed by stacking rectangular parallelepiped structures of different or same thicknesses in the Z-axis direction and staggering them in the X-axis direction or the Y-axis direction.

[0062] The gradient structure adopts a stepped design to increase the heat exchange area and improve the heat dissipation effect. The gradient structure is arranged in an equidistant or unequally spaced array in the X and Y axis directions, which can optimize the heat load in different areas, thereby more effectively managing and dissipating heat, and significantly improving the thermal response speed and heat distribution uniformity of the heat spreader.

[0063] Furthermore, the misalignment distance of each layer of the rectangular parallelepiped structure may be 20 μm to 30 μm.

[0064] like Figure 8 As shown, the optimized gradient structure is a three-dimensional structure formed by a groove of a certain depth from the side close to the lower substrate to the side close to the upper substrate; the groove is preferably arranged in the middle part of the gradient structure and communicated with the side wall.

[0065] The optimized gradient structure can increase the capillary driving force by opening a groove of a certain depth from the side close to the lower substrate to the side close to the upper substrate in the above-mentioned gradient structure. It has the advantages of high permeability and low flow resistance, and can further improve the thermal conductivity performance.

[0066] In some embodiments of the present invention, the height of the wick unit in the Z-axis direction is preferably 100 μm-75 mm; it should be noted that the height of the wick unit in the Z-axis direction is not particularly limited, and those skilled in the art can make a reasonable choice according to actual needs.

[0067] In some embodiments of the present invention, the thickness of each type of wick unit is not particularly limited, and those skilled in the art can make a reasonable selection according to actual needs.

[0068] In some embodiments of the present invention, it should be understood that according to the needs of heat dissipation of the electronic equipment used, six types of liquid-wicking core unit designs, including concave angle structure, convex angle structure, asymmetric trapezoidal pillar structure, blade bionic structure, gradient structure and optimized gradient structure, can be selected to apply one design in the heat spreader, or multiple designs can be selected to be applied in different areas in the same heat spreader.

[0069] The present invention optimizes the directional wick structure according to the direction and intensity of the heat flow, greatly improving the heat transfer capacity, heat transfer efficiency, anti-gravity performance, reliability and directional transmission characteristics of the heat spreader, can achieve the best heat dissipation effect, can meet the heat dissipation needs of electronic equipment with high heat flux density, help to improve the local thermal management capabilities of the heat spreader, can optimize the heat load in different areas, so as to more effectively manage and disperse heat, improve the thermal response speed and heat distribution uniformity of the heat spreader, effectively enhance the control of heat dissipation of electronic equipment, and can better adapt to different heat dissipation scenarios and performance requirements.

[0070] The heat spreader can be customized according to the specific appearance and spatial layout requirements of various electronic devices to meet the heat dissipation requirements of different products. Its sophisticated design not only saves space, but also does not cause additional occupation of the overall design of the equipment, and maximizes the use of limited space resources.

[0071] In some embodiments of the present invention, based on the different 3D printing materials of the directional wick structure, the directional wick structure can be obtained by direct printing or printing combined with post-processing.

[0072] For example, a common 3D printing resin material can be used to obtain a directional wick structure by printing and molding combined with post-processing, which includes the following steps: using ultra-high precision light-curing additive manufacturing technology to integrally print array-arranged wick units on a lower substrate; chemically plating the integrally printed array-arranged wick units; and oxidizing the chemically plated array-arranged wick units.

[0073] For example, a directional wick structure can be obtained by 3D printing a hydrophilic resin slurry in a direct printing and molding manner, which includes the following steps: using ultra-high precision light-curing 3D printing technology to integrate the hydrophilic resin slurry into an array of wick units on the lower substrate.

[0074] Furthermore, the hydrophilic resin slurry may be selected from a photosensitive resin slurry or a hydrogel resin slurry to which an emulsifier is added.

[0075] (3) The side of the lower substrate with the directional liquid wick structure is co-edge-joined with the periphery of the upper substrate and sealed, and a position for placing the liquid injection tube 5 is reserved for liquid injection and degassing, such as Fig. 9 and Fig.10 shown.

[0076] (4) Precisely inject liquid, perform primary degassing, and perform secondary degassing on the sealed upper substrate and lower substrate.

[0077] (5) Seal and cut off the injection tube part, and finally package it to form a complete directional liquid absorption core heat sink with directional transmission characteristics.

[0078] In the present invention, the directional liquid wick vapor chamber can be a vapor chamber with gas and liquid coplanar, such as Figure 1 and Fig. 9 As shown; it can also be a gas-liquid hot plate with different surfaces, such as Figure 2 and Fig.10 shown.

[0079] The upper and lower substrates of the gas-liquid heterogeneous heat spreader are connected by array-arranged support columns 6 , and the directional liquid wick structure 2 is in close contact with the lower substrate 1 and spaced apart from the upper substrate 4 .

[0080] The present invention focuses on the preparation of high-performance directional liquid-wick heat-sinks and their applications in electronic equipment cooling systems, especially for occasions with strict requirements for heat flow directionality control. A variety of innovative directional liquid-wick structure designs and a variety of heat-sink preparation methods are adopted to meet specific heat dissipation requirements, provide customized solutions for thermal management of electronic equipment, and solve the heat dissipation problem in electronic equipment with strict requirements for heat flow directionality control.

[0081] The present invention provides an efficient and precise heat flow control technology. The heat spreader with a liquid-absorbing core structure having directional transmission characteristics can accurately control the temperature of the heat source and prevent the equipment from overheating with its excellent high heat rectification ratio capability. At the same time, its unique unidirectional heat transfer characteristic can effectively prevent heat backflow and protect the equipment from damage, so that it can flexibly select a suitable preparation method according to the heat dissipation requirements and be integrated into various electronic devices, which helps to reduce the power consumption of the equipment, enhance the endurance of the equipment, and bring users a more efficient and lasting use experience. It can effectively cope with the growing heat dissipation challenges of modern electronic equipment, such as electronic equipment thermal management, building integrated design, solar water heaters, thermal cooling systems, and heat dissipation of microelectronic devices.

[0082] The second aspect of the present invention provides a directional liquid wick vapor chamber, and the directional liquid wick vapor chamber is prepared by the preparation method provided by the first aspect of the present invention.

[0083] The third aspect of the present invention provides an application of a directional liquid wick vapor chamber for heat dissipation of electronic equipment, which is a directional liquid wick vapor chamber prepared by the preparation method provided by the first aspect of the present invention or a directional liquid wick vapor chamber provided by the second aspect of the present invention.

[0084] According to the difference in the structural materials of the directional liquid absorbent core prepared in the present invention, the preparation method of the directional liquid absorbent core vapor chamber in the present invention is further described in combination with the following examples.

[0085] Example 1

[0086] Print the directional liquid-wick structure with ordinary 3D printing resin materials, the steps are as follows Fig.11 shown.

[0087] S1. Select ultra-thin materials with excellent high thermal conductivity as the upper and lower substrates, with a thickness of 0.025-0.075mm. The material is metal or non-metal. The upper and lower substrates can be made of the same or different materials.

[0088] S2. Use ultra-high precision photo-curing additive manufacturing technology and micro-scale additive manufacturing process to print the directional liquid-absorbing core structure with directional transmission characteristics on the lower substrate and ensure a firm and stable connection with the lower substrate. This manufacturing process not only fully utilizes the advantages of ultra-high precision photo-curing additive manufacturing technology and micro-scale additive manufacturing process, but also optimizes the array structure at the microscopic level, thereby improving their overall performance and durability.

[0089] S3, chemically plate the integrated printed directional liquid wick structure with directional transmission characteristics. The chemical plating is to metallize the directional liquid wick structure through five steps of degreasing-roughening-sensitization-activation-chemical plating. By copper plating on the surface of ordinary materials, its thermal conductivity is enhanced.

[0090] S4, oxidizing the liquid wick structure after chemical plating. The purpose is to oxidize the metal element after metallization into metal oxide, thereby enhancing the hydrophilicity of the directional liquid wick structure and the support column structure. The oxidation treatment steps are: soaking the article in a 20-30wt% H2O2 solution for 20min-30min, then taking it out for thorough water washing, and finally drying it with hot air from a hair dryer.

[0091] S5. The upper and lower substrates are sealed around the periphery, and the upper and lower substrates are sealed around the periphery, leaving a position for the injection tube to be inserted for subsequent injection and degassing operations.

[0092] After the bonding process of the upper substrate and the lower substrate is completed, it is important to ensure that the two are seamlessly fitted to ensure the tightness of the structure. In addition to the reserved injection tube position, the remaining edges of the fittings must be accurately placed in a heat sealer or laser welding machine for sealing to ensure that the final package structure is both strong and stable. This series of sophisticated operation processes is designed to achieve efficient connection between substrates and meet high standards of package quality requirements. The upper and lower substrates that have undergone this packaging process, together with the injection tube, form a composite substrate.

[0093] S6. Liquid is accurately injected into the composite substrate through the injection pipe at the tail using a special injection device. The volume of the injected liquid working fluid accounts for 30% to 90% of the volume of the substrate cavity. Common working fluids include but are not limited to deionized water, ethanol, fluorinated liquid and acetone. After the injection is completed, the composite substrate is placed in a low-temperature environment to maintain the low temperature state of the injected liquid. Subsequently, the low-temperature liquid-injected composite substrate is degassed to reduce the air pressure in the cavity to below 100 Pa. This process facilitates the gas-liquid phase change cycle in the cavity, thereby improving the efficiency of heat transfer.

[0094] S7, sealing and cutting off the injection tube part, and finally packaging it to form a complete heat spreader with a liquid wick structure having directional transmission characteristics.

[0095] Example 2

[0096] Print the directional liquid-absorbing core structure with 3D printing hydrophilic resin slurry, the steps are as follows Fig.12 shown.

[0097] N1. Select ultra-thin materials with excellent high thermal conductivity as the upper and lower substrates, which is the same as the above step S1.

[0098] N2. Select a 3D printing hydrophilic resin slurry with high thermal conductivity and excellent temperature resistance. The hydrophilic resin slurry includes but is not limited to photosensitive resin slurry with added emulsifier and hydrogel resin slurry. Traditional photocurable resin slurry often faces the problems of low surface energy and non-hydrophilicity after curing, which limits its performance in specific application scenarios. The present invention introduces an improved solution to add 3%-8% emulsifier to the photosensitive resin. This significantly increases the surface energy of the resin after curing, giving it good hydrophilicity, thereby greatly improving the surface properties of the material.

[0099] The emulsifier has a wide range of choices, including but not limited to: nonionic emulsifiers, such as polyoxyethylene ethers and nonylphenol polyoxyethylene ethers; anionic emulsifiers, such as sodium dodecyl sulfate and sodium dodecylbenzene sulfonate; and cationic emulsifiers, such as hexadecyltrimethylammonium chloride.

[0100] By precisely controlling the printing parameters and selecting and optimizing the resin, a firm bond between the directional wick structure and the lower substrate can be achieved, and the hydrophilic property can be improved. In addition, the hydrophilic resin slurry can also be a hydrogel resin slurry.

[0101] N3. Using ultra-high precision light-curing 3D printing technology, the hydrophilic resin slurry is integrated into an integrated form to accurately construct the directional liquid-absorbing core structure with directional transmission characteristics on the lower substrate.

[0102] N4, seal and package the upper and lower substrates along four common edges, and reserve a position for the injection tube. The injection tube is used for injection and degassing. The specific operation steps are the same as the above step S5.

[0103] N5, the sealed upper and lower plates are precisely injected with liquid, degassed once, and degassed twice. The specific operation steps are the same as the above step S6.

[0104] N6, seal and cut off the injection tube part, and finally package it to form a complete heat spreader with a directional liquid absorption core structure with directional transmission characteristics.

[0105] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing a directional liquid wick vapor chamber, characterized in that: The following steps are involved: preparing a lower substrate and an upper substrate; Printing a directional wick structure on one side of the lower substrate using 3D printing technology, wherein the directional wick structure comprises a plurality of wick units, and the plurality of wick units are arranged in an array with equal or unequal spacing along the X and Y axis directions; The side of the lower substrate with the directional liquid wick structure is co-edge-joined with the periphery of the upper substrate and sealed and packaged, and a position for placing a liquid injection tube is reserved for liquid injection and degassing; Precisely injecting liquid, performing primary degassing, and performing secondary degassing on the sealed upper substrate and the lower substrate; The liquid injection tube part is sealed and cut off, and finally packaged to form a complete directional liquid absorption core heat spreader with directional transmission characteristics.

2. The method for preparing a directional liquid wick vapor chamber according to claim 1, characterized in that: The liquid wick unit is selected from one or more of a concave angle structure, a convex angle structure, an asymmetric trapezoidal pillar structure, a blade bionic structure, a gradient structure and an optimized gradient structure; wherein The concave angle structure is a three-dimensional structure in which a closed plane formed by two parallel arcs extends to a certain height in the Z-axis direction; The convex angle structure is a three-dimensional structure formed by extending a closed plane formed by two parallel V-shaped lines to a certain height in the Z-axis direction; The asymmetric trapezoidal pillar structure is a three-dimensional structure formed by stretching a trapezoidal plane arranged at an acute angle or a right angle to the lower substrate along a set direction to a certain thickness; The blade bionic structure is a three-dimensional structure formed by stretching a blade-shaped closed surface arranged at an acute angle with the lower substrate in the Z-axis direction to a certain thickness; The gradient structure is a three-dimensional structure formed by stacking rectangular parallelepiped structures of different or same thicknesses in the Z-axis direction and displacing them in the X-axis direction or the Y-axis direction; The optimized gradient structure is a three-dimensional structure formed by opening a groove of a certain depth from the side close to the lower substrate to the side close to the upper substrate.

3. The method for preparing a directional liquid wick vapor chamber according to claim 2, characterized in that: The height of the liquid wick unit in the Z-axis direction is 100 μm-75 mm.

4. The method for preparing a directional liquid wick vapor chamber according to claim 2, characterized in that: The thickness of the lower substrate and the upper substrate are independently 0.025-0.075 mm.

5. The method for preparing a directional liquid wick vapor chamber according to claim 2, characterized in that: The directional liquid wick vapor chamber is a vapor chamber with gas and liquid coplanarly or a vapor chamber with gas and liquid skewedly arranged on different surfaces.

6. The method for preparing a directional liquid wick vapor chamber according to claim 2, characterized in that: Printing a directional wick structure on one side of the lower substrate using 3D printing technology includes the following steps: The array of liquid-wick units is integrated and printed on the lower substrate using ultra-high precision light-curing additive manufacturing technology; Chemically plating the integrated printed array-arranged wick units; The liquid-absorbing core units arranged in the array after chemical plating are subjected to oxidation treatment.

7. The method for preparing a directional liquid wick vapor chamber according to claim 2, characterized in that: Printing a directional wick structure on one side of the lower substrate using 3D printing technology includes the following steps: Select hydrophilic resin slurry for 3D printing; Using ultra-high precision light-curing 3D printing technology, the hydrophilic resin slurry is integrated onto the lower substrate to form an array of liquid-absorbing core units.

8. The method for preparing a directional liquid wick vapor chamber according to claim 7, characterized in that: The hydrophilic resin slurry is a photosensitive resin slurry or a hydrogel resin slurry with an emulsifier added.

9. A directional liquid wick vapor chamber prepared by the method for preparing a directional liquid wick vapor chamber according to any one of claims 1 to 8.

10. Use of a directional wick vapor chamber prepared by the preparation method of the directional wick vapor chamber according to any one of claims 1 to 8 or the directional wick vapor chamber according to claim 9 in heat dissipation of electronic equipment.

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