SLM-based aluminum-based vapor chamber manufacturing method and vapor chamber

Abstract

The application discloses a kind of aluminum-based heat plate manufacturing method and heat plate based on SLM, the method includes establishing the three-dimensional model of aluminum-based heat plate;When the area that first cover plate and second cover plate need dense forming is printed, first printing process parameters are used, and when porous wick structure is printed, second printing process parameters are used, first printing process parameters and second printing process parameters at least include laser power and scanning speed;Start SLM equipment, and sequentially print second cover plate, porous wick structure and first cover plate, and form reserved port, to obtain heat plate blank;After aluminum-based heat plate is obtained after processing heat plate blank;After vacuumizing aluminum-based heat plate, working fluid is injected into aluminum-based heat plate through reserved port, and reserved port is blocked.The application realizes the integrated forming of heat plate shell, wick and radiator, eliminates interface thermal resistance, and significantly improves temperature uniformity and heat load capacity.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, specifically to a method for manufacturing an aluminum-based vapor chamber based on SLM and the vapor chamber itself. Background Technology

[0002] Vapor chambers are typically made of copper and consist of a first cover plate and a lower base plate encapsulated by brazing or diffusion welding to form a cavity. Inside, a porous material (such as sintered copper powder, metal mesh, or microgrooves) serves as the wick, and a certain amount of working fluid (such as deionized water or ethanol) is filled in. This type of vapor chamber utilizes the capillary action, vaporization, and condensation phase change of the working fluid within the wick to transfer heat, achieving efficient heat dissipation.

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

[0004] Therefore, a new technological solution is needed. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a method for manufacturing an aluminum-based heat exchanger based on SLM and a heat exchanger, so as to at least solve the problem of low interfacial thermal resistance and 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] This invention provides a method for manufacturing an aluminum-based heat spreader based on SLM, comprising:

[0008] A three-dimensional model of an aluminum-based heat exchange plate is established. The three-dimensional model includes a first cover plate and a second cover plate. After the first cover plate and the second cover plate are closed, a cavity structure with a reserved opening is formed. The inner surface of the cover plate has a porous liquid absorption core structure. The porous liquid absorption core structure is a TPMS topological three-dimensional pore network.

[0009] Dry aluminum or aluminum alloy powder is laid into the forming cylinder of an 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 need to be densely formed, a first printing process parameter is used, and when printing the porous liquid-absorbing core structure, a second printing process parameter is used. Both the first printing process parameter and the second printing process parameter include at least laser power and scanning speed, and the energy density of the first printing process parameter is greater than the energy density of the second printing process parameter.

[0011] Start the SLM device and print the second cover plate, the porous liquid-absorbing core structure and the first cover plate in sequence, and form the reserved opening to obtain a heat spreader blank;

[0012] The aluminum-based heat-spreading plate is obtained by post-processing the heat-spreading plate blank. The post-processing includes one or more of the following: clearing the reserved opening, removing the excess material of the outer support, cleaning the inside of the heat-spreading plate blank, stress heat treatment, and grinding the mating surface.

[0013] After the aluminum-based heat exchanger is evacuated, a working fluid is injected into the heat exchanger through the reserved port, and the reserved port is then sealed.

[0014] Furthermore, 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 into a single 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 porous network is 50%-80%, and the characteristic scale of the pores is 50-500 micrometers.

[0018] Furthermore, the aluminum or aluminum alloy powder is an Al-Si pre-alloyed powder with a particle size range of 15-53 micrometers.

[0019] Furthermore, the first cover plate, the second cover plate, and the porous liquid-absorbing core structure are printed in an inert gas protective environment to prevent aluminum oxidation.

[0020] Furthermore, when printing the second cover plate and the first cover plate, scanning is performed in an interlaced rotational scanning manner, and the laser power in the first printing process parameters is 380w, the scanning speed is 1000mm / s, the scanning spacing is 0.1mm, and the layer thickness is 30 micrometers, so as to fully melt the powder;

[0021] When printing the porous liquid-absorbing core structure, the solid boundary of the porous liquid-absorbing core structure is scanned first, and then the interior is filled. The laser power in the second printing process parameters is 100-200w, and the scanning speed is 1600-2000mm / s, so that the powder does not completely melt and forms a sintered bridge.

[0022] Furthermore, the unblocking of the reserved opening includes:

[0023] The reserved opening is cleared by ultrasonic vibration or flushing.

[0024] The stress heat treatment includes:

[0025] The heat spreader blank is placed at 300°C for 2 hours and then slowly cooled down.

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

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

[0028] The present invention also provides a heat spreader, which is formed by the aluminum-based heat spreader manufacturing method described above. It includes a first cover plate, a second cover plate and a porous liquid-absorbing core structure. 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. The porous liquid-absorbing core structure is integrally connected to the inner side of the first cover plate and the second cover plate respectively. The porous liquid-absorbing core structure is a TPMS topological three-dimensional pore network.

[0029] There is a gap between the porous liquid-absorbing core structure on the first cover plate and the porous liquid-absorbing core structure on the second cover plate.

[0030] Furthermore, a plurality of spaced-apart support pillars are formed between the porous liquid-absorbing core structure on the first cover plate and the porous liquid-absorbing core structure on the second cover plate, and the support pillars and the adjacent porous liquid-absorbing core structures are integrally formed; or

[0031] The outer side of the first cover plate or the second cover plate is formed with a plurality of heat dissipation fins spaced apart to increase the heat exchange area.

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

[0033] This invention discloses a method for manufacturing an aluminum-based vapor chamber based on SLM (Self-Drying Molding). The method uses SLM technology to print an aluminum-based vapor chamber shell containing a TPMS (Porous Phosphate-Mechanical System) wicking core in a single process, eliminating the thermal resistance at the welding interface in traditional split manufacturing and improving heat transfer efficiency. Furthermore, the TPMS topological pore network allows for precise control of capillary performance. Combined with zoned control of SLM process parameters (high energy density printing of a dense shell, low energy density molding of a porous structure), the permeability and capillary force balance of the wicking core are optimized. Finally, the aluminum alloy material reduces weight, and the integral SLM molding avoids aluminum welding defects (such as porosity and deformation). Post-processing (stress heat treatment, etc.) further ensures structural strength and sealing. The pre-reserved opening design also reduces complex processes such as traditional vacuum brazing, improving production consistency. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a flowchart illustrating a method for manufacturing an aluminum-based heat spreader based on SLM according to an embodiment of the present invention.

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

[0037] Figure 3 The maximum heat load of the heat exchanger manufactured according to the SLM-based aluminum-based heat exchanger manufacturing method in this embodiment of the invention;

[0038] Figure 4 This describes the temperature uniformity of a heat spreader manufactured according to an SLM-based aluminum-based heat spreader manufacturing method in an embodiment of the present invention.

[0039] Figure 5 The thermal resistance of the heat exchange plate manufactured according to the SLM-based aluminum-based heat exchange plate manufacturing method in this embodiment of the invention;

[0040] Figure 6 This is a side cross-sectional view of a heat spreader according to an embodiment of the present invention;

[0041] Figure 7 This is a side cross-sectional view of a heat dissipation finned heat sink according to an embodiment of the present invention.

[0042] Figure 8 This is a partially enlarged schematic diagram of a porous liquid-absorbing core structure in a heat spreader according to an embodiment of the present invention.

[0043] The reference numerals in the drawings of this invention are as follows:

[0044] 1. First cover plate; 2. Second cover plate; 3. Cavity structure; 4. Porous liquid suction core structure; 5. Support column; 6. Heat dissipation fins. Detailed Implementation

[0045] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0046] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one 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 aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

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

[0049] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0050] With the rapid development of microelectronics technology and power devices, electronic products are evolving towards high performance, high power, and portable miniaturization. This has led to a significant increase in heat generation per unit area, with local heat flux density on chips reaching hundreds of watts per square centimeter. Such high heat flux density can easily cause 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 solve the problem of high heat flux density heat dissipation.

[0051] Vapor chambers can transfer a large amount of heat energy by utilizing the vaporization and condensation phase change of the working fluid, making them one of the effective solutions to the aforementioned problems. Traditional vapor chambers are typically made of copper, with an upper cover plate and a lower base plate encapsulated by brazing or diffusion welding to form a cavity. The interior is filled with a porous material as a liquid wick and a certain amount of working fluid.

[0052] However, existing vapor chamber manufacturing processes have some limitations. First, in traditional vapor chambers, the shell and wick are usually manufactured separately and then assembled. The wick is often made using sintered copper powder, metal mesh, or microgrooves, and then bonded to the inner wall of the shell. This structure inevitably introduces contact thermal resistance at the interface between the wick and the shell, affecting heat transfer efficiency.

[0053] Furthermore, the multi-part assembly process increases the risk of interface defects and leakage. Copper-based vapor chambers are also relatively heavy, limiting their use in weight-sensitive applications such as aerospace and mobile electronic devices. Replacing the vapor chamber material with lighter aluminum alloys presents challenges due to aluminum's lower thermal conductivity and the difficulty of fabricating complex internal microstructures using traditional processing methods, making it difficult to guarantee heat dissipation performance and manufacturing reliability. Finally, the pore morphology of the internal liquid wick structure (such as sintered porous materials) in traditional vapor chambers cannot be precisely controlled. Capillary force and permeability are contradictory and difficult to balance, potentially leading to insufficient liquid supply or drying out under ultra-high heat flux densities, thus limiting the maximum heat transfer capacity of the vapor chamber.

[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 complex metal parts.

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

[0056] However, there is currently no mature solution that can directly and integrally mold the entire vapor chamber (including the shell and internal wicking core) using additive manufacturing. Existing attempts often only print certain components (such as the wicking core or support frame), and then still require subsequent assembly and encapsulation, failing to fundamentally eliminate interfacial thermal resistance and assembly errors. Furthermore, for additive manufacturing of aluminum alloys, due to aluminum's high reflectivity and high thermal conductivity, controlling porosity and deformation during the printing process is challenging, requiring optimization of process parameters to obtain a structure that is both dense and has the designed porosity.

[0057] Therefore, there is an urgent need for a new technical solution that utilizes the advantages of SLM additive manufacturing to achieve integrated molding of the shell, liquid wick, and heat dissipation structure of the aluminum-based heat spreader, thereby improving heat transfer performance while taking into account weight and manufacturing reliability, and meeting the heat dissipation needs of high heat flux density electronic devices.

[0058] Based on this, the embodiments of this specification propose a processing solution: such as Figures 1-2 As shown, this invention relates to a method for manufacturing an aluminum-based vapor chamber based on SLM (Surface Mount Technology), and the vapor chamber itself. The vapor chamber is integrally formed from aluminum or aluminum alloy and includes a first cover plate 1, a second cover plate 2, and a vacuum-sealed cavity. A porous liquid-absorbing core structure 4 is integrated within the cavity, and the liquid-absorbing core is metallurgically bonded to the inner wall of the cavity. The liquid-absorbing core employs a biomimetic three-period minimal surface (TPMS) structure to achieve a synergy between high porosity and continuous channels, providing strong capillary force and good permeability, enabling efficient liquid recirculation. Heat dissipation fins 6 are integrally integrated on the outer surface of the vapor chamber for directly and efficiently transferring heat to the surrounding environment, thereby avoiding the contact thermal resistance between the vapor chamber and the radiator in traditional methods.

[0059] The fabrication method employs selective laser melting (SLM) additive manufacturing to directly print the aforementioned vapor chamber as a whole. This includes constructing a three-dimensional model containing a porous TPMS wick and a cavity; adjusting parameters such as laser power, scanning speed, and layer thickness to prepare the dense cavity wall and porous wick structure 4; removing residual powder from the inner cavity after printing; vacuuming and filling with working fluid; and sealing. This invention achieves integrated molding of the vapor chamber shell, wick, and heat sink, eliminating interfacial thermal resistance, significantly improving temperature uniformity and heat load capacity, and is suitable for efficient heat dissipation of high heat flux density electronic devices.

[0060] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0061] Example 1

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

[0063] Step S102: Establish a three-dimensional model of the aluminum-based heat exchange plate. The three-dimensional model includes a first cover plate 1 and a second cover plate 2. After the first cover plate 1 and the second cover plate 2 are closed, a cavity structure 3 with a reserved opening is formed. The inner surface of the cavity structure 3 has a porous liquid absorption core structure 4. The porous liquid absorption core structure 4 is a TPMS topology three-dimensional pore network.

[0064] One method is to use 3D modeling software to model the aluminum-based heat exchanger to obtain a three-dimensional model of the aluminum-based heat exchanger.

[0065] The first cover plate 1 and the second cover plate 2 both have side walls, so that when they are closed, they form a cavity structure 3 with a reserved opening.

[0066] The first cover plate 1 and the second cover plate 2 described in this application are only for showing the installation position of the porous liquid absorption core structure 4, and 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 the sidewall between the first cover plate 1 and the second cover plate 2, a multi-hole liquid-absorbing core structure is disposed on the inner side of the corresponding first cover plate 1 or second cover plate 2.

[0068] In some embodiments, the three-dimensional model also includes multiple support columns 5, which support the first cover plate 1 and the second cover plate 2 to support the first cover plate 1 and the second cover plate 2 when the printed aluminum-based heat spreader is in a vacuum.

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

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

[0071] In some embodiments, the first cover plate 1 and the second cover plate 2 have overlapping edges reserved in the three-dimensional model so that the first cover plate 1 and the second cover plate 2 and the corresponding sidewalls are metallurgically connected as an integral structure.

[0072] Specifically, in this invention, the thickness of the first cover plate 1 and the second cover plate 2 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% to 80%, the pore feature scale is 50 to 500 micrometers, and the diameter of the reserved opening ranges from 1 to 3 mm.

[0073] For example, the dimensions of the 3D 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 liquid-absorbing core structure 4 in this embodiment can adopt a Gyroid-type three-period minimal curved surface structure, occupying most of the cavity volume and forming a connected three-dimensional pore network. Furthermore, the periodic unit size of the Gyroid structure in this embodiment is 0.5 mm, the average pore diameter is approximately 0.2 mm, and the porosity is approximately 60%.

[0075] Step S104: The dried aluminum or aluminum alloy powder is laid into the forming cylinder of the SLM equipment, wherein the SLM equipment 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 powders suitable for SLM process, with a particle size range of 15-53μm and good flowability and dryness.

[0077] For example, aluminum or aluminum alloy powder can be AlSi10Mg aluminum alloy premixed powder.

[0078] The powder supply system loads the powder into the SLM equipment, which is equipped with an adjustable-power fiber laser (maximum power 500W) and an inert gas protective environment (high-purity argon) to prevent aluminum from oxidizing during printing. The forming base plate is preheated to a suitable temperature (around 150°C) to reduce thermal stress.

[0079] Step S106: When printing the areas where the first cover plate 1 and the second cover plate 2 need to be densely formed, the first printing process parameters are used, and when printing the porous liquid-absorbing core structure 4, the second printing process parameters are used. Both the first printing process parameters and the second printing process parameters include at least laser power and scanning speed. The energy density of the first printing process parameters is greater than the energy density of the second printing process parameters.

[0080] Laser energy density refers to the laser energy contained per unit area on the cross-section of a laser beam; a higher laser power results in a higher energy density.

[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 requiring dense forming, such as the sidewalls 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 interleaved rotational scanning method is used to reduce anisotropy. The first printing process parameters include a laser power of 380W, a scanning speed of 1000mm / s, a scanning interval of 0.1mm, and a layer thickness of 30 micrometers to fully melt the powder. When printing the porous liquid-absorbing core structure 4, the solid boundary of the porous liquid-absorbing core structure 4 is scanned first, and then the interior is filled. The second printing process parameters include a laser power of 100-200W and a scanning speed of 1600-2000mm / s to ensure that the powder is not completely melted, thus forming a sintered bridge.

[0084] Step S108: Start the SLM equipment and print the second cover plate 2, the porous liquid absorption core 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, after starting the SLM (Selective Laser Melting) additive manufacturing equipment, the process is 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 support structure are first formed, and then they are connected to the area of ​​the first cover plate 1 to finally complete the solid construction of the entire heat spreader.

[0087] During the printing process, the powder spreading and molten pool status are monitored in real time, and scanning parameters are adjusted as needed to ensure the quality of molten deposition in critical areas. After printing, the workpiece is slowly cooled to room temperature and then removed. The entire printing process can be carried out under argon protection, and it involves approximately 1200 cross-sections. The printed blank adheres to the substrate and is removed after cooling.

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

[0089] Step S110: After post-processing the heat-spreading plate blank, an aluminum-based heat-spreading plate is obtained. The post-processing includes one or more of the following: clearing the reserved opening, removing excess material from the outer support, cleaning the inside of the heat-spreading plate blank, stress heat treatment, and grinding the mating surface.

[0090] After printing to obtain the vapor chamber blank, the formed vapor chamber blank is removed from the forming base plate, and excess material from the outer supports is removed. Unsintered residual powder inside the cavity is then poured out through the pre-drilled opening, while ultrasonic vibration or flushing is applied to ensure the channels are unobstructed. The vapor chamber blank is then subjected to stress-relief heat treatment, held at 300°C in a protective atmosphere for 2 hours, followed by slow cooling to release residual printing stress and stabilize dimensions. Finally, after heat treatment, necessary machining or surface finishing can be performed on the appearance of the vapor chamber blank, such as grinding the mating surfaces, but care must be taken to ensure that the cavity is not damaged.

[0091] Step S112: After vacuuming the aluminum-based heat exchanger, inject the working fluid liquid into the aluminum-based heat exchanger through the reserved port and then seal the reserved port.

[0092] Specifically, the post-treated heat spreader is used to evacuate the interior of the cavity through a pre-reserved opening, achieving a vacuum level of 10. -3 -10 -4 Pa. Then, a predetermined amount of working fluid (acetone) is filled through the pre-drilled port. The filling volume is approximately 30%-70% of the cavity volume, ensuring sufficient liquid coverage of the wick while leaving space for steam generation. After filling, for small-diameter filling holes integrally printed on the housing, a matching aluminum plug can be inserted and welded securely; if a threaded filling hole is used, a metal plug is screwed in and sealed with solder. After sealing, the finished vapor chamber undergoes helium leak testing or vacuum pressure testing to ensure the cavity is completely sealed and leak-free.

[0093] Specifically, the heat-soaking plate blank is placed on a vibrating platform, and loose powder inside the cavity is poured out through a pre-designed opening. Compressed air is then used to purge the cavity, ensuring that any remaining powder in the fine pores is also cleaned. Next, the heat-soaking plate blank is placed in a muffle furnace and held at 300°C for 2 hours to eliminate internal stress and improve the material's mechanical properties. After heat treatment, the shell is checked to ensure it remains vacuum-sealed. Since the dense area of ​​the SLM molding process has virtually no through-hole defects, helium mass spectrometry leak detection confirms that the cavity leakage rate is less than 1×10⁻⁶. -9 Pa·m 3 / s, meeting the vacuum requirements. Subsequently, the cavity is evacuated and filled with working fluid through the pre-reserved opening: the heat exchange plate blank is connected to the vacuum filling device, and the vacuum is evacuated to approximately 1×10⁻⁶. -4 At pressure 100°C, approximately 5 mL of acetone working fluid is injected to fill the cavity to about 50%. After injection, the pre-reserved opening is quickly sealed using electron beam welding to form a molten weld. A leak test is performed again after sealing to confirm no leakage, thus completing the fabrication of the heat spreader.

[0094] Step S114: Install the sealed heat spreader sample on the test platform and test its heat transfer performance at different power levels.

[0095] Specifically, such as Figures 3-5 As shown, during the performance test, the temperature distribution of the heat spreader after being heated was observed to verify its temperature uniformity; the heating power was gradually increased to the design maximum heat load to check whether the heat spreader could operate stably, and the thermal resistance was calculated.

[0096] More specifically, the test used a 20mm×20mm heating block attached to the central 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 the surface temperature of the heat spreader differed by only about 1.3℃ between the center and the edge when the heating power was 100W, proving its good temperature uniformity. When the power was increased to 200W, the heat spreader still operated stably without any signs of drying out, with a maximum surface temperature of about 85℃ 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 shaped using a laser. After the shaped powder is heat-treated and cleaned, the airtightness of the shaped blank can be checked. If the airtightness is not a problem, the shaped blank can be vacuumed, injected with liquid (injecting working fluid), sealed, and finally the performance test can be performed.

[0098] The porous liquid-absorbing core 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 are no delamination or adhesive materials at the interface, which ensures that the heat is transferred from the wall to the liquid-absorbing core in an efficient and unobstructed manner.

[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 of Embodiment 1. It 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. The porous liquid-absorbing core structure 4 is integrally connected to the inner side of the first cover plate 1 and the second cover plate 2 respectively. 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] In this embodiment, the heat spreader is constructed entirely of aluminum or aluminum alloy through an integrated molding process, forming a vacuum-sealed flat cavity structure 3.

[0102] The first cover plate 1 and the second cover plate 2 are fused together to form a vacuum-sealed cavity; a porous liquid-absorbing core structure 4 is integrally connected to the shell inside the cavity. The liquid-absorbing core structure is a biomimetic three-period minimal surface (TPMS) topology, such as a Gyroid, to achieve a synergy between high porosity and mechanical continuity.

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

[0104] Specifically, when the heat exchanger is working, the working fluid at the heat source vaporizes on the surface of the wick, and the vapor diffuses into the cavity space to condense at the far end. The condensate returns through the capillary action of the wick, and the cycle continues to conduct heat evenly.

[0105] Furthermore, a plurality of spaced support columns 5 are formed 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, and the support columns 5 and the adjacent porous liquid-absorbing core structure 4 are integrally formed.

[0106] Among them, the support column 5 is used to maintain the smooth flow of the vapor-liquid channel, and at the same time supports the upper / second cover plate 2 to prevent the cavity from deforming due to vacuum pressure difference.

[0107] Furthermore, the outer surface of the heat spreader can be integrally formed with additional structures according to heat dissipation requirements.

[0108] For example, when heat exchange with air convection is required, several 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, thereby enabling the heat spreader to achieve a high degree of integration of evaporation, conduction and heat dissipation functions, reducing intermediate thermal resistance and improving overall heat transfer efficiency.

[0109] The heat dissipation fins 6 can be 100mm long (equal to the length of the plate), 5mm high, and 1mm thick, with a fin spacing of 3mm, and are arranged along the plate to cover the heat source area.

[0110] Among them, the heat dissipation fins 6 are made of aluminum alloy directly printed on the plate surface, which has good thermal contact, requires no later installation, and greatly improves the heat dissipation capacity of the heat spreader to the air.

[0111] In some embodiments, an integrally connected liquid cooling plate can be printed on the outer surface of the first cover plate 1 for use in liquid cooling heat dissipation scenarios.

[0112] In practice, either finned air cooling or liquid 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 positive effects of the present invention are:

[0114] 1. The heat spreader shell and liquid wick are formed in one piece by SLM process. The liquid wick and the cavity wall are continuously metallurgically connected, eliminating the need for post-assembly. This avoids the thermal resistance and poor contact problems at the interface between the traditional sintered core and shell, and improves the heat conduction efficiency and temperature uniformity of the heat spreader.

[0115] 2. Employing a biomimetic TPMS three-dimensional interconnected suction core, high capillary suction power and good permeability can be achieved simultaneously. The gradually tortuous and interconnected pores of the TPMS structure resemble the capillary network in biological tissue, increasing the surface area for capillary action and reducing liquid flow resistance. Compared to traditional randomly sintered porous materials, the pore size distribution of the TPMS structure can be precisely designed, better reconciling the contradiction between capillary force and permeability.

[0116] 3. Using 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 liquid suction core and optimizing the heat dissipation structure during SLM printing. Furthermore, aluminum is easily integrated with other aluminum cooling components, avoiding electrochemical corrosion that may occur from contact with dissimilar metals.

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

[0118] 5. Utilizing SLM additive manufacturing to directly form complex internal structures eliminates the multiple sintering, pressing, and welding processes involved in traditional vapor chamber manufacturing, simplifying the production process. Simultaneously, by eliminating numerous sealing welding points and retaining only the final filling seal, the overall leakage risk is significantly reduced, improving the yield rate and 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 address different heat source shapes and heat flow requirements.

[0119] In this specification, the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the product embodiments described later, since they correspond to the methods, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions in the system embodiments.

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

Claims

1. A method for manufacturing an aluminum-based heat spreader based on SLM, characterized in that, include: A three-dimensional model of an aluminum-based heat exchange plate is established. The three-dimensional model includes a first cover plate and a second cover plate. After the first cover plate and the second cover plate are closed, a cavity structure with a reserved opening is formed. The inner surface of the cover plate has a porous liquid absorption core structure. The porous liquid absorption core structure is a TPMS topological three-dimensional pore network. Dry aluminum or aluminum alloy powder is laid into the forming cylinder of an 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 need to be densely formed, a first printing process parameter is used, and when printing the porous liquid-absorbing core structure, a second printing process parameter is used. Both the first printing process parameter and the second printing process parameter include at least laser power and scanning speed, and the energy density of the first printing process parameter is greater than the energy density of the second printing process parameter. The SLM device is started, and the second cover plate, the porous liquid-absorbing core structure, and the first cover plate are printed sequentially to form the reserved opening, thereby obtaining a heat spreader blank. When printing the second cover plate and the first cover plate, an interlaced rotational scanning method is used, and the laser power in the first printing process parameters is 380W, the scanning speed is 1000mm / s, the scanning interval is 0.1mm, and the layer thickness is 30μm, so as to fully melt the powder. When printing the porous liquid-absorbing core structure, the solid boundary of the porous liquid-absorbing core structure is scanned first, and then the interior is filled. The laser power in the second printing process parameters is 100-200W, and the scanning speed is 1600-2000mm / s, so that the powder is not completely melted and a sintering bridge is formed. The aluminum-based heat-spreading plate is obtained by post-processing the heat-spreading plate blank. The post-processing includes one or more of the following: clearing the reserved opening, removing the excess material of the outer support, cleaning the inside of the heat-spreading plate blank, stress heat treatment, and grinding the mating surface. After the aluminum-based heat exchanger is evacuated, a working fluid is injected into the heat exchanger through the reserved port, and the reserved port is then sealed.

2. The method for manufacturing an aluminum-based heat spreader according to claim 1, characterized in that, 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 into a single structure.

3. The method for manufacturing an aluminum-based heat spreader according to claim 1, characterized in that, 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 porous network is 50%-80%, and the characteristic scale of the pores is 50-500 micrometers.

4. The method for manufacturing an aluminum-based heat spreader according to claim 1, characterized in that, The aluminum or aluminum alloy powder is an Al-Si pre-alloyed powder with a particle size range of 15-53 micrometers.

5. The method for manufacturing an aluminum-based heat spreader according to claim 1, characterized in that, The first cover plate, the second cover plate, and the porous liquid-absorbing core structure are printed in an inert gas protective environment to prevent aluminum from oxidizing.

6. The method for manufacturing an aluminum-based heat spreader according to claim 1, characterized in that, The unblocking of the reserved opening includes: The reserved opening is cleared by ultrasonic vibration or flushing. The stress heat treatment includes: The heat spreader blank is placed at 300°C for 2 hours and then slowly cooled down.

7. The method for manufacturing an aluminum-based heat spreader according to claim 1, characterized in that, After evacuating the aluminum-based heat spreader, the vacuum level of the aluminum-based heat spreader is 10. -3 -10 -4 Pa; The working fluid is acetone, and the amount of the working fluid injected is 30%-70% of the internal volume of the cavity structure.

8. A heat spreader, characterized in that, The aluminum-based heat exchange plate is formed using the manufacturing method of any one of claims 1 to 7, comprising a first cover plate, a second cover plate, and a porous liquid-absorbing core structure. 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 liquid-absorbing core structure is integrally connected to the inner side of the first cover plate and the second cover plate, respectively. The porous liquid-absorbing core structure is a TPMS topological three-dimensional pore network. There is a gap between the porous liquid-absorbing core structure on the first cover plate and the porous liquid-absorbing core structure on the second cover plate.

9. The heat spreader according to claim 8, characterized in that, A plurality of spaced support pillars are formed between the porous liquid-absorbing core structure on the first cover plate and the porous liquid-absorbing core structure on the second cover plate, and the support pillars and the adjacent porous liquid-absorbing core structures are integrally formed; or The outer side of the first cover plate or the second cover plate is formed with a plurality of heat dissipation fins spaced apart to increase the heat exchange area.

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