Aluminum-based vapor chamber manufacturing method based on SLM and vapor chamber

Abstract

The invention discloses an SLM-based aluminum-based vapor chamber manufacturing method and a vapor chamber. The method comprises the following steps: establishing a three-dimensional model of an aluminum-based vapor chamber; first printing process parameters are adopted when areas, needing to be compactly formed, of the first cover plate and the second cover plate are printed, second printing process parameters are adopted when the porous wick structure is printed, and the first printing process parameters and the second printing process parameters at least comprise laser power and scanning speed; sLM equipment is started, a second cover plate, a porous liquid absorption core structure and a first cover plate are printed in sequence, a reserved opening is formed, and a vapor chamber blank is obtained; and the aluminum-based vapor chamber is obtained after the vapor chamber blank is subjected to aftertreatment. And after the aluminum-based vapor chamber is vacuumized, working medium liquid is injected into the aluminum-based vapor chamber through the reserved opening, and the reserved opening is blocked. According to the vapor chamber, integrated forming of the vapor chamber shell, the wick and the radiator is achieved, the interface thermal resistance is eliminated, and the temperature equalizing performance and the thermal load capacity are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of heat exchange technology, and in particular to a method for manufacturing an aluminum-based vapor chamber based on SLM and the vapor chamber. Background Art

[0002] A vapor chamber is typically made of copper, with a first cover plate and a lower base plate brazed or diffusion-bonded to form a cavity. A porous material (such as sintered copper powder, metal mesh, or microgrooves) is placed inside as a wick, which is then filled with a certain amount of fluid (such as deionized water or ethanol). This type of vapor chamber utilizes the capillary action, vaporization, and condensation phase transitions of the fluid in the wick to transfer heat, achieving efficient heat dissipation.

[0003] In existing technology, the vapor chamber shell and wick are typically manufactured separately and then assembled. The wick and shell are joined by welding or bonding, which inevitably creates interfacial thermal resistance, affecting heat transfer efficiency. Furthermore, the multi-piece assembly process increases the risk of interface defects and leakage, reducing product reliability and consistency. Furthermore, the pore morphology of traditional wick structures cannot be precisely controlled, making it difficult to balance capillary force and permeability, limiting the maximum heat transfer capacity of the vapor chamber.

[0004] Based on this, a new technical solution is needed. Summary of the Invention

[0005] In view of this, an embodiment of the present invention provides an aluminum-based vapor chamber manufacturing method and vapor chamber based on SLM, so as to at least solve the problem of low interface thermal resistance conduction efficiency caused by separate manufacturing and reassembly in the existing process.

[0006] The embodiments of the present invention provide the following technical solutions:

[0007] An embodiment of the present invention provides a method for manufacturing an aluminum-based vapor chamber based on SLM, comprising:

[0008] Establish a three-dimensional model of an aluminum-based vapor chamber, comprising a first cover plate and a second cover plate. The first and second cover plates, when combined, form a cavity structure with a reserved opening, and both inner surfaces have a porous wick structure, which is a TPMS topological three-dimensional pore network.

[0009] Laying the dried aluminum or aluminum alloy powder into a forming cylinder of a SLM device, wherein the SLM device is equipped with a power-adjustable fiber laser;

[0010] When printing the areas of the first cover plate and the second cover plate that require dense formation, first printing process parameters are used, and when printing the porous wick structure, second printing process parameters are used, wherein the first printing process parameters and the second printing process parameters both include at least laser power and scanning speed, and the energy density of the first printing process parameters is greater than the energy density of the second printing process parameters;

[0011] Starting the SLM device, and sequentially printing the second cover plate, the porous wick structure, and the first cover plate, and forming the reserved opening to obtain a vapor chamber blank;

[0012] The aluminum-based vapor chamber is obtained by post-processing the vapor chamber blank, wherein the post-processing includes one or more of dredging the reserved opening, removing the peripheral support residual material, cleaning the interior of the vapor chamber blank, stress heat treatment, and grinding the joint surface;

[0013] After the aluminum-based vapor chamber is vacuumed, a working fluid is injected into the aluminum-based vapor chamber through the reserved opening, and the reserved opening is sealed.

[0014] Furthermore, overlapping edges are reserved between the first cover plate and the second cover plate in the three-dimensional model, so that the first cover plate and the second cover plate are metallurgically connected to form an integrated structure.

[0015] Furthermore, the thickness of the first cover plate and the second cover plate ranges from 1 to 3 mm;

[0016] The total thickness of the three-dimensional model ranges from 4 to 10 mm;

[0017] The porosity of the TPMS topological three-dimensional pore network is 50%-80%, and the characteristic scale of the pores is 50-500 microns.

[0018] Furthermore, the aluminum or aluminum alloy powder is Al-Si pre-alloyed powder, and the particle size range is 15-53 microns.

[0019] Furthermore, the first cover plate, the second cover plate and the porous wick structure are printed in an inert gas protection environment to prevent oxidation of aluminum.

[0020] Furthermore, when printing the second cover plate and the first cover plate, scanning is performed in an interlaced rotation scanning manner, and the first printing process parameters include a laser power of 380W, a scanning speed of 1000mm / s, a scanning pitch of 0.1mm, and a layer thickness of 30 microns, so as to fully melt the powder;

[0021] When printing the porous wick structure, the physical boundary of the porous wick structure is first scanned, and then the interior is filled. In the second printing process parameters, the laser power is 100-200w and the scanning speed is 1600-2000mm / s, so that the powder is not completely melted and a sintered bridge is formed.

[0022] Furthermore, the reserved opening dredging includes:

[0023] Unclogging the reserved opening by ultrasonic vibration or flushing;

[0024] The stress heat treatment comprises:

[0025] The heat spreader blank was placed at 300° C. and kept at this temperature for 2 hours, and then slowly cooled.

[0026] Furthermore, after the aluminum-based heat plate is evacuated, the vacuum degree of the aluminum-based heat plate is 10 -3 -10 -4 Pa;

[0027] The working fluid is acetone, and the working fluid injection amount is 30%-70% of the internal volume of the cavity structure.

[0028] The present invention further provides a vapor chamber, formed using any of the above-described aluminum-based vapor chamber manufacturing methods, comprising a first cover plate, a second cover plate, and a porous wick structure, wherein a vacuum cavity structure is formed between the first cover plate and the second cover plate, the cavity structure being filled with a working fluid, and the porous wick structure being integrally connected to the inner sides of the first cover plate and the second cover plate, respectively, wherein the porous wick structure is a TPMS topological three-dimensional pore network;

[0029] There is a space between the porous wick structure on the first cover plate and the porous wick structure on the second cover plate.

[0030] Further, a plurality of spaced support columns are formed between the porous wick structure on the first cover plate and the porous wick structure on the second cover plate, and the support columns and the adjacent porous wick structures are integrally formed; or

[0031] A plurality of heat dissipation fins arranged at intervals are formed on the outer side of the first cover plate or the second cover plate to increase the heat exchange area.

[0032] Compared with the prior art, the at least one technical solution adopted in the embodiment of the present invention can achieve the following beneficial effects:

[0033] The present invention provides an SLM-based aluminum-based heat sink manufacturing method, which uses SLM technology to print an aluminum-based heat sink shell containing a TPMS porous liquid wick at one time, eliminating the welding interface thermal resistance in traditional split manufacturing and improving the heat transfer efficiency. The TPMS topological pore network can achieve precise capillary performance regulation. Combined with the zoning control of SLM process parameters (high energy density printing of dense shells and low energy density forming of porous structures), the permeability and capillary force balance of the liquid wick are also optimized. Finally, since the aluminum alloy material reduces weight and the SLM overall forming avoids aluminum welding defects (such as pores and deformation), combined with the post-processing process (stress heat treatment, etc.), the structural strength and sealing are further guaranteed. The reserved port design also reduces complex processes such as traditional vacuum brazing, thereby improving production consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 This is a flow chart of a method for manufacturing an aluminum-based vapor chamber based on SLM according to an embodiment of the present invention;

[0036] Figure 2 This is an example of a process for manufacturing an aluminum-based vapor chamber based on SLM according to an embodiment of the present invention;

[0037] Figure 3 is the maximum heat load of the vapor chamber manufactured according to the SLM-based aluminum vapor chamber manufacturing method according to an embodiment of the present invention;

[0038] Figure 4 The temperature balancing performance of the vapor chamber manufactured according to the SLM-based aluminum vapor chamber manufacturing method according to the embodiment of the present invention;

[0039] Figure 5 is the thermal resistance of the vapor chamber manufactured according to the SLM-based aluminum vapor chamber manufacturing method according to an embodiment of the present invention;

[0040] Figure 6 A side cross-sectional view of a vapor chamber according to an embodiment of the present invention;

[0041] Figure 7 A side cross-sectional view of a vapor chamber with heat dissipation fins according to an embodiment of the present invention;

[0042] Figure 8 This is a partially enlarged schematic diagram of a porous wick structure in a vapor chamber according to an embodiment of the present invention.

[0043] The accompanying drawings of the present invention are as follows:

[0044] 1. First cover plate; 2. Second cover plate; 3. Cavity structure; 4. Porous wick structure; 5. Support column; 6. Heat dissipation fins. DETAILED DESCRIPTION

[0045] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0046] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0047] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0048] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0049] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples, however, one skilled in the art will appreciate that the examples can be practiced without these specific details.

[0050] With the rapid development of microelectronics technology and power devices, electronic products are moving towards high performance, high power, portability, and miniaturization. This has led to an increasing heat generation per unit area, with local heat flux densities on chips reaching hundreds of watts per square centimeter. This high heat flux can easily lead to overheating failures in space-constrained electronic devices, severely impacting device performance and reliability. Therefore, there is an urgent need to develop efficient heat dissipation technologies to address this high heat flux challenge.

[0051] Vapor chambers are an effective solution to this problem, as they utilize the phase transitions of the working fluid between vaporization and condensation to transfer large amounts of heat energy. Traditional vapor chambers are typically made of copper, with an upper cover and lower base plate brazed or diffusion-bonded to form a cavity. A porous material acts as a wick within the cavity, which is then filled with a predetermined amount of working fluid.

[0052] However, existing vapor chamber manufacturing processes have several limitations. First, the shell and wick of a traditional vapor chamber are typically manufactured separately and then assembled. The wick is often made of sintered copper powder, metal mesh, or micro-grooves, and then bonded to the inner wall of the shell. This structure inevitably creates contact thermal resistance at the interface between the wick and shell, affecting heat transfer efficiency.

[0053] In addition, the multi-piece assembly process increases the risk of interface defects and leakage. Copper-based heat spreaders are also heavy and are limited in weight-sensitive applications (such as aerospace and mobile electronic devices). When the heat spreader material is replaced with a lighter aluminum alloy, its heat dissipation performance and manufacturing reliability are difficult to guarantee because aluminum's thermal conductivity is not as good as copper and traditional processing methods are difficult to manufacture complex internal microstructures. Finally, the pore morphology of the internal liquid wick structure of the traditional heat spreader (such as sintered porous materials) cannot be precisely controlled, and capillary force and permeability are a pair of contradictions that are difficult to take into account. As a result, insufficient liquid supply or drying up may occur under ultra-high heat flux density, limiting the maximum heat transfer capacity of the heat spreader.

[0054] In recent years, the development of additive manufacturing (3D printing) technology has provided new ideas for the innovation of thermal management devices. Among them, selective laser melting (SLM), as an important method of metal additive manufacturing, can directly print and form complex metal parts.

[0055] For example, 3D printing can directly print microstructured wicks for loop heat pipe evaporators or heat dissipation substrates with built-in cooling channels. 3D printing can create complex biomimetic structures that are difficult to process with traditional methods, such as continuous porous networks like tri-periodic minimal surfaces (TPMS) to optimize capillary circulation channels.

[0056] However, there is currently no mature solution that relies entirely on additive manufacturing to directly form the entire heat spreader (including the shell and internal wick) in one piece. Existing attempts often only print certain components (such as the wick or support frame), which still require subsequent assembly and packaging, failing to fundamentally eliminate interfacial thermal resistance and assembly errors. At the same time, for additive manufacturing of aluminum alloy materials, due to the high reflectivity and high thermal conductivity of aluminum, controlling porosity and deformation during the printing process is challenging, and the process parameters need to be optimized to obtain a structure that is both dense and has designed porosity.

[0057] Therefore, a new technical solution is urgently needed to utilize the advantages of SLM additive manufacturing to achieve the integrated molding of the shell, liquid absorption core and heat dissipation structure of the aluminum-based heat sink, while improving the heat transfer performance while taking into account the weight and manufacturing reliability to meet the heat dissipation needs of high heat flux density electronic devices.

[0058] Based on this, this specification proposes a solution: Figures 1-2 As shown, the present invention relates to a method for manufacturing an aluminum-based heat spreader based on SLM and a heat spreader. The heat spreader is constructed of an integrally formed aluminum or aluminum alloy material, and includes a first cover plate 1, a second cover plate 2, and a vacuum-sealed cavity. A porous wick structure 4 is integrated in the cavity, and the wick is metallurgically bonded to the inner wall of the cavity. The wick adopts a bionic three-periodic minimal surface (TPMS) structure to achieve the synergy of high porosity and continuous channels, provide strong capillary force and good permeability, and can efficiently reflux liquid. Heat dissipation fins 6 are integrated into the outer surface of the heat spreader to directly and efficiently conduct heat to the surrounding environment, thereby avoiding the contact thermal resistance between the traditional heat spreader and the radiator.

[0059] The fabrication method utilizes a selective laser melting (SLM) additive manufacturing process to directly print the vapor chamber. This involves constructing a three-dimensional model containing the TPMS porous wick and cavity. Adjusting parameters such as laser power, scanning speed, and layer thickness to create a dense cavity wall and porous wick structure 4, respectively, the printing process is complete. Residual powder within the cavity is removed, and the cavity is vacuumed, filled with a working fluid, and sealed. This method achieves the integrated formation of the vapor chamber housing, wick, and heat sink, eliminating interfacial thermal resistance and significantly improving temperature uniformity and heat load capacity. It is suitable for efficient heat dissipation in high-heat-flux electronic devices.

[0060] The following describes the technical solutions provided by various embodiments of the present application in conjunction with the accompanying drawings.

[0061] Example 1

[0062] like Figures 1-2 As shown, an embodiment of the present invention provides a method for manufacturing an aluminum-based vapor chamber based on SLM, comprising:

[0063] Step S102: Establish a three-dimensional model of the aluminum-based heat sink. The three-dimensional model includes a first cover plate 1 and a second cover plate 2. When the first cover plate 1 and the second cover plate 2 are covered, a cavity structure 3 with a reserved opening is formed, and the inner side surfaces both have a porous wick structure 4. The porous wick structure 4 is a TPMS topological three-dimensional pore network.

[0064] The aluminum-based vapor chamber can be modeled using 3D modeling software to obtain a three-dimensional model of the aluminum-based vapor chamber.

[0065] Wherein, the first cover plate 1 and the second cover plate 2 both have side walls, so that when they are covered together, a cavity structure 3 with a reserved opening is formed.

[0066] The first cover plate 1 and the second cover plate 2 described in the present application are only used to illustrate the installation position of the porous absorbent core structure 4, and they are not two cover plates that can be separated from each other.

[0067] For example, in a three-dimensional model including a first cover plate 1 , a second cover plate 2 and a side wall between the first cover plate 1 and the second cover plate 2 , the porous wick structure is disposed on the inner side of the corresponding first cover plate 1 or the second cover plate 2 .

[0068] In some of the embodiments, the three-dimensional model also includes a plurality of support columns 5, which are used to support the first cover plate 1 and the second cover plate 2, so as to support the first cover plate 1 and the second cover plate 2 when the printed aluminum-based heat sink is vacuumed.

[0069] Among them, TPMS is a bionic three-periodic minimal surface structure to ensure the balance between capillary force and permeability.

[0070] The reserved opening is used to discharge the residual powder inside after printing is completed and to inject the working fluid.

[0071] In some of the embodiments, overlapping edges are reserved in the three-dimensional model between the first cover plate 1 and the second cover plate 2 so that the first cover plate 1 and the second cover plate 2 and the corresponding side walls are metallurgically connected to form an integrated structure.

[0072] Specifically, in the present invention, the thickness range of the first cover plate 1 and the second cover plate 2 is 1-3 mm; the total thickness range of the three-dimensional model is 4-10 mm; the porosity of the TPMS topological three-dimensional pore network is 50%-80%, the characteristic scale of the pores is 50-500 microns, and the diameter range of the reserved opening is 1-3 mm.

[0073] For example, the length, width and height of the three-dimensional model can be 100mm*100mm*4mm. The thickness of the first cover plate 1 and the second cover plate 2 is 1mm, the thickness of the internal cavity is 2mm, and the diameter of the reserved opening is 2mm.

[0074] The porous wick structure 4 of this embodiment can employ a Gyroid-type three-periodic minimal surface structure, occupying the majority of the cavity volume and forming a connected three-dimensional pore network. In this embodiment, the Gyroid structure has a periodic unit size of 0.5 mm, an average pore diameter of approximately 0.2 mm, and a porosity of approximately 60%.

[0075] Step S104: Laying the dried aluminum or aluminum alloy powder into a forming cylinder of an SLM device, wherein the SLM device is equipped with a power-adjustable fiber laser.

[0076] In this step, aluminum or aluminum alloy powder is selected as the printing raw material, preferably Al-Si series pre-alloyed powder suitable for SLM process, with a particle size range of 15-53 μm and good fluidity and dryness.

[0077] For example, the aluminum or aluminum alloy powder may be an AlSi10Mg aluminum alloy premix powder.

[0078] The powder is loaded into the powder feed system of the SLM machine, which is equipped with a power-adjustable fiber laser (maximum power 500W) and an inert gas protection environment (high-purity argon) to prevent aluminum oxidation during the printing process. The build plate is preheated to a suitable temperature (around 150°C) to reduce thermal stress.

[0079] Step S106: When printing the areas of the first cover plate 1 and the second cover plate 2 that require dense forming, the first printing process parameters are used, and when printing the porous wick structure 4, the second printing process parameters are used. The first printing process parameters and the second printing process parameters both include at least laser power and scanning speed, and the energy density of the first printing process parameters is greater than the energy density of the second printing process parameters.

[0080] Among them, laser energy density refers to the laser energy contained per unit area on the cross-section of the beam. If the laser power is large, the energy density is large.

[0081] In this step, scanning parameters (printing process parameters) can be set separately according to the molding requirements of different areas of the 3D model.

[0082] Specifically, in areas that require dense molding, such as the side walls between the cover plates, a higher energy density is used to fully melt the powder.

[0083] For example, when printing the second cover plate 2 and the first cover plate 1, an interlaced rotational scanning pattern was used to reduce anisotropy. The first printing process parameters included a laser power of 380W, a scanning speed of 1000mm / s, a scanning pitch of 0.1mm, and a layer thickness of 30μm to fully sinter the powder. When printing the porous wick structure 4, the solid boundary of the porous wick structure 4 was scanned first, followed by filling the interior. The second printing process parameters included a laser power of 100-200W and a scanning speed of 1600-2000mm / s to prevent the powder from completely melting and forming sintered bridges.

[0084] Step S108 , start the SLM equipment, and print the second cover plate 2 , the porous wick structure 4 and the first cover plate 1 in sequence, and form a reserved opening to obtain a heat spreader blank.

[0085] In this step, the SLM (Selective Laser Melting) additive manufacturing process is activated and printed layer by layer according to the slicing program. The laser beam scans and melts the flattened aluminum or aluminum alloy powder layer along a set path.

[0086] Specifically, the second cover plate 2, the porous liquid-absorbing core structure 4 and the supporting structure are first formed, and then connected with the first cover plate 1 area, and finally the physical construction of the entire heat sink is completed.

[0087] During the printing process, the powder coating and melt pool conditions are monitored in real time, and scanning parameters are adjusted as necessary to ensure the quality of the deposit in key areas. After printing is complete, the workpiece is slowly cooled to room temperature and the formed part is removed. The entire printing process, which consists of approximately 1,200 cross-section layers, can be performed under argon protection. The printed blank is attached to a substrate and removed after cooling.

[0088] By setting different process parameters for different areas, it is possible to ensure that the dense areas and porous areas in the same workpiece are formed at the same time and both meet the expected density requirements during path planning printing.

[0089] Step S110: The aluminum-based vapor chamber is obtained by post-processing the vapor chamber blank. The post-processing includes one or more of clearing the reserved opening, removing the peripheral support residual material, cleaning the interior of the vapor chamber blank, stress heat treatment, and grinding the joint surface.

[0090] After printing is completed and the vapor chamber blank is obtained, the formed vapor chamber blank is removed from the forming base plate and the peripheral support residue is removed. The unsintered residual powder inside the cavity is poured out through the reserved opening, and ultrasonic vibration or flushing is applied to ensure that the channel is unobstructed. The vapor chamber blank is then subjected to stress relief heat treatment, kept at 300°C in a protective atmosphere for 2 hours and then slowly cooled to release the residual stress of printing and stabilize the size. Finally, after heat treatment, the appearance of the vapor chamber blank can be machined or surface finished as necessary, such as polishing the mating surface, but it should be ensured that the cavity is not damaged.

[0091] Step S112: After the aluminum-based vapor chamber is vacuumed, a working fluid is injected into the aluminum-based vapor chamber through the reserved opening, and the reserved opening is sealed.

[0092] Specifically, the post-processed heat spreader is used to evacuate the interior of the cavity through the reserved opening, and the vacuum degree reaches 10 -3 -10 -4 Pa. Then, a predetermined amount of working fluid (acetone) is filled in through the reserved port. The working fluid filling volume is about 30%-70% of the cavity volume, which ensures that there is enough liquid to cover the wick and leaves space for steam generation. After the filling is completed, the small-diameter filling hole integrally printed on the shell can be inserted with a matching aluminum plug and welded securely; if a threaded filling hole is used, a metal screw plug is screwed in and sealed with solder. After the sealing is completed, the finished heat sink is subjected to a helium leak test or a vacuum pressure test to ensure that the cavity is completely sealed and leak-free.

[0093] Specifically, the vapor chamber blank was placed on a vibration platform, and the loose powder in the cavity was poured out through a previously designed reserved opening. Compressed air was then blown to ensure that any remaining powder in the tiny pores was also removed. The vapor chamber blank was then placed in a muffle furnace and kept at 300°C for 2 hours to eliminate internal stress and improve the material's mechanical properties. After heat treatment, the shell was checked for vacuum sealing. Since the dense SLM-molded area was essentially free of through-hole defects, helium mass spectrometry leak testing confirmed a cavity leakage rate of less than 1×10 -9 Pa·m 3 / s, meeting the vacuum requirements. Then, the cavity is evacuated and filled with working fluid through the reserved opening: the heat sink blank is connected to the vacuum filling device and the vacuum is evacuated to about 1×10 -4 At 1.50 Pa, approximately 5 mL of acetone is quantitatively injected to fill the cavity to approximately 50%. After injection, the reserved opening is quickly sealed using electron beam welding, forming a molten weld to seal it. After sealing, a leak test is conducted again to confirm that there are no leaks, completing the vapor chamber fabrication.

[0094] Step S114: Install the sealed vapor chamber sample on a test platform and perform a heat transfer performance test at different powers.

[0095] Specifically, if Figures 3-5 As shown in the figure, during the performance test, the temperature distribution of the vapor chamber after heating is observed to verify its temperature uniformity; the heating power is gradually increased to the designed maximum heat load to check whether the vapor chamber can operate stably, and the thermal resistance is calculated.

[0096] More specifically, the test used a heating block with a heating size of 20mm×20mm close to the center area of ​​the second cover plate 2 of the heat spreader as a simulated heat source. The heating power was gradually increased from 20W, and the temperature was recorded after 20 minutes of steady-state operation at each level. The results showed that when the heating power was 100W, the surface temperature of the heat spreader only differed by about 1.3°C between the center and the edge, proving that it had good temperature uniformity; when the power was increased to 200W, the heat spreader was still able to operate stably without signs of drying out, with a maximum surface temperature of about 85°C and a total thermal resistance of about 0.04K / W. The above experiments verified the excellent heat dissipation performance and reliability of the aluminum-based integrated heat spreader of the present invention under high heat flux conditions.

[0097] like Figure 2 As shown, in a specific embodiment of the present invention, a CAD model can be established first, then the model can be sliced, a suitable material (such as aluminum or aluminum alloy powder) can be selected, the parameters of the SLM equipment can be set, and the powder can be melted and formed using a laser. After forming, heat treatment and cleaning operations are performed, and the air tightness of the molded blank is checked. If there is no problem with the air tightness, the molded blank can be vacuumed, injected (injected with working fluid), sealed, and finally a performance test is performed.

[0098] The porous wick structure 4 of the present invention is directly integrated with the first cover plate 1 and the second cover plate 2 through the SLM additive manufacturing process. There is no delamination or adhesive material at the interface, ensuring that the process of heat transfer from the wall to the wick is efficient and unobstructed.

[0099] Example 2

[0100] like Figures 6-8 As shown, the present invention also provides a heat spreader, which is formed by the aluminum-based heat spreader manufacturing method as described in any one of Example 1, and includes a first cover plate 1, a second cover plate 2 and a porous liquid-absorbing core structure 4. A vacuum cavity structure 3 is formed between the first cover plate 1 and the second cover plate 2. The cavity structure 3 is filled with a working fluid, and the inner sides of the first cover plate 1 and the second cover plate 2 are respectively integrally connected to the porous liquid-absorbing core structure 4, and the porous liquid-absorbing core structure 4 is a TPMS topological three-dimensional pore network; there is a gap between the porous liquid-absorbing core structure 4 on the first cover plate 1 and the porous liquid-absorbing core structure 4 on the second cover plate 2.

[0101] The heat spreader of this embodiment is entirely made of aluminum or aluminum alloy material through an integrated molding process to form a vacuum-sealed flat cavity structure 3 .

[0102] The first and second cover plates 1 and 2 are welded together at their peripheries to form a vacuum-sealed cavity. A porous wick structure 4, integrally connected to the housing, is located within the cavity. The wick structure is a biomimetic tri-periodic minimal surface (TPMS) topology, such as a gyroid, achieving a synergistic combination of high porosity and mechanical continuity.

[0103] The first cover plate 1 and the second cover plate 2 are respectively metallurgically bonded to the corresponding porous wick structure 4 , such as by 3D printing to form an integrated structure.

[0104] Specifically, when the heat sink is working, the working fluid at the heat source vaporizes on the surface of the wick, the vapor diffuses in the cavity space to the far end and condenses, and the condensed liquid returns through the capillary action of the wick, continuing to circulate to evenly conduct heat.

[0105] Furthermore, a plurality of spaced support columns 5 are formed between the porous wick structure 4 on the first cover plate 1 and the porous wick structure 4 on the second cover plate 2 , and the support columns 5 and the adjacent porous wick structures 4 are integrally formed.

[0106] The support column 5 is used to maintain the vapor-liquid passage unobstructed, and at the same time supports the upper / second cover plate 2 to prevent the cavity from being deformed due to the vacuum pressure difference.

[0107] Furthermore, the outer surface of the vapor chamber can be integrally formed with an additional structure according to heat dissipation requirements.

[0108] For example, when convection heat exchange with the air is required, a number of parallel heat dissipation fins 6 are printed on the outer surface of the first cover plate 1. The heat dissipation fins 6 and the first cover plate 1 are integrally formed, so that the heat spreader achieves a high degree of integration of evaporation, conduction and heat dissipation functions, reduces the intermediate thermal resistance, and improves the overall heat transfer efficiency.

[0109] The heat dissipation fins 6 may be 100 mm long (same length as the board surface), 5 mm high, and 1 mm thick, with a 3 mm fin spacing, and are arranged along the board surface to cover the heat source area.

[0110] Among them, the heat dissipation fins 6 are directly printed on the board surface from aluminum alloy, which has good thermal contact and does not require subsequent installation, greatly improving the ability of the heat spreader to dissipate heat into the air.

[0111] In some of the embodiments, an integrally connected liquid cooling plate may be printed on the outer surface of the first cover plate 1 to apply liquid cooling heat dissipation scenarios.

[0112] In a specific implementation, either fin air cooling or liquid cooling plate cooling can be selected as needed, or even used simultaneously in different areas to achieve the best cooling effect.

[0113] Compared with the prior art, the present invention has the following positive effects:

[0114] 1. The vapor chamber shell and wick are formed in one step using the SLM process. The wick and cavity wall are connected by a continuous metallurgical connection, eliminating the need for post-assembly. This avoids the thermal resistance and poor contact issues at the interface between the traditional sintered wick and the shell, and improves the thermal conductivity and temperature uniformity of the vapor chamber.

[0115] 2. The biomimetic TPMS three-dimensional interconnected wick achieves both high capillary suction and good permeability. The TPMS structure's pores gradually curve and connect, similar to the capillary network in biological tissue, increasing the surface area for capillary action and reducing fluid flow resistance. Compared to traditional randomly sintered porous materials, the TPMS structure's pore size distribution can be precisely designed, effectively balancing capillary force and permeability.

[0116] 3. The use of aluminum and aluminum alloys as the substrate significantly reduces weight compared to commonly used copper, making it suitable for weight-sensitive applications (such as aerospace). Although aluminum has a lower thermal conductivity than copper, excellent heat dissipation performance can still be achieved by integrating a high-efficiency wick and optimizing the heat dissipation structure during the SLM printing process. Furthermore, aluminum is easily integrated with other aluminum cooling components, avoiding the potential for electrochemical corrosion caused by dissimilar metal contact.

[0117] 4. The heat dissipation fins 6 printed directly on the outer surface achieve seamless connection between the heat spreader and the downstream cooling device (air-cooled radiator), which reduces the need for additional thermal interfaces and makes the device more compact and efficient.

[0118] 5. Utilizing SLM additive manufacturing to directly mold complex internal structures eliminates the multiple sintering, pressing, and welding steps typically required in traditional vapor chamber manufacturing, streamlining the production process. Furthermore, by eliminating numerous sealing welds and retaining only the final filling seal, the overall risk of leakage is significantly reduced, improving both the yield rate and operational reliability of finished products. The digital nature of SLM printing also facilitates rapid iterative design optimization. Customized vapor chamber structures can be achieved by adjusting the model to accommodate varying heat source geometries and heat flow requirements.

[0119] In this specification, references to the same or similar parts between the various embodiments can be made to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the product embodiments described later, since they correspond to the methods, the description is relatively simple, and the relevant parts can be referred to the partial description of the system embodiment.

[0120] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for manufacturing an aluminum-based heat sink based on SLM, characterized in that: include: Establish a three-dimensional model of an aluminum-based vapor chamber, comprising a first cover plate and a second cover plate. The first and second cover plates, when combined, form a cavity structure with a reserved opening, and both inner surfaces have a porous wick structure, which is a TPMS topological three-dimensional pore network. Laying the dried aluminum or aluminum alloy powder into a forming cylinder of a SLM device, wherein the SLM device is equipped with a power-adjustable fiber laser; When printing the areas of the first cover plate and the second cover plate that require dense formation, first printing process parameters are used, and when printing the porous wick structure, second printing process parameters are used, wherein the first printing process parameters and the second printing process parameters both include at least laser power and scanning speed, and the energy density of the first printing process parameters is greater than the energy density of the second printing process parameters; Starting the SLM device, and sequentially printing the second cover plate, the porous wick structure, and the first cover plate, and forming the reserved opening to obtain a vapor chamber blank; The aluminum-based vapor chamber is obtained by post-processing the vapor chamber blank, wherein the post-processing includes one or more of dredging the reserved opening, removing the peripheral support residual material, cleaning the interior of the vapor chamber blank, stress heat treatment, and grinding the joint surface; After the aluminum-based vapor chamber is vacuumed, a working fluid is injected into the aluminum-based vapor chamber through the reserved opening, and the reserved opening is sealed.

2. The method for manufacturing an aluminum-based vapor chamber according to claim 1, wherein: The first cover plate and the second cover plate have overlapping edges reserved in the three-dimensional model, so that the first cover plate and the second cover plate are metallurgically connected to form an integrated structure.

3. The method for manufacturing an aluminum-based vapor chamber according to claim 1, wherein: The thickness of the first cover plate and the second cover plate ranges from 1 to 3 mm; The total thickness of the three-dimensional model ranges from 4 to 10 mm; The porosity of the TPMS topological three-dimensional pore network is 50%-80%, and the characteristic scale of the pores is 50-500 microns.

4. The method for manufacturing an aluminum-based vapor chamber according to claim 1, wherein: The aluminum or aluminum alloy powder is Al-Si pre-alloyed powder, and the particle size range is 15-53 microns.

5. The method for manufacturing an aluminum-based vapor chamber according to claim 1, wherein: The first cover plate, the second cover plate and the porous wick structure are printed in an inert gas protection environment to prevent oxidation of aluminum.

6. The method for manufacturing an aluminum-based vapor chamber according to claim 1, wherein: When printing the second cover plate and the first cover plate, scanning is performed in an interlaced rotation scanning mode, and the first printing process parameters include a laser power of 380W, a scanning speed of 1000mm / s, a scanning pitch of 0.1mm, and a layer thickness of 30 microns to fully melt the powder; When printing the porous wick structure, the physical boundary of the porous wick structure is first scanned, and then the interior is filled. In the second printing process parameters, the laser power is 100-200w and the scanning speed is 1600-2000mm / s, so that the powder is not completely melted and a sintered bridge is formed.

7. The method for manufacturing an aluminum-based vapor chamber according to claim 1, wherein: The reserved opening dredging includes: Unclogging the reserved opening by ultrasonic vibration or flushing; The stress heat treatment comprises: The heat spreader blank was placed at 300° C. and kept at this temperature for 2 hours, and then slowly cooled.

8. The method for manufacturing an aluminum-based vapor chamber according to claim 1, wherein: After the aluminum-based heat plate is evacuated, the vacuum degree of the aluminum-based heat plate is 10 -3 -10 -4 Pa; The working fluid is acetone, and the working fluid injection amount is 30%-70% of the internal volume of the cavity structure.

9. A heat sink, characterized in that: The aluminum-based vapor chamber is formed using the manufacturing method of any one of claims 1 to 8, comprising a first cover plate, a second cover plate, and a porous wick structure, wherein a vacuum cavity structure is formed between the first cover plate and the second cover plate, the cavity structure is filled with a working fluid, and the porous wick structure is integrally connected to the inner sides of the first cover plate and the second cover plate, respectively, wherein the porous wick structure is a TPMS topological three-dimensional pore network; There is a space between the porous wick structure on the first cover plate and the porous wick structure on the second cover plate.

10. The vapor chamber according to claim 9, wherein: A plurality of spaced support columns are formed between the porous wick structure on the first cover plate and the porous wick structure on the second cover plate, and the support columns and the adjacent porous wick structures are integrally formed; or A plurality of heat dissipation fins arranged at intervals are formed on the outer side of the first cover plate or the second cover plate to increase the heat exchange area.

Images