Method for manufacturing a vacuum chuck

Abstract

The application discloses a manufacturing method of a vacuum chuck. Specifically comprising: processing a base material to form a chuck base body and an adsorption layer; performing surface treatment on the chuck base body and the adsorption layer, clamping the chuck base body and the adsorption layer to form a workpiece to be welded, and then placing the workpiece into a vacuum diffusion welding furnace to perform welding; placing the workpiece after diffusion welding into a vacuum brazing furnace to perform welding; performing surface treatment on the workpiece, and detecting a shape and position tolerance and a linear size of the workpiece; if the shape and position tolerance meets a first preset value, and the linear size meets a second preset value, then detecting a leak of a closed cavity formed in the workpiece; and if a leakage rate of the cavity is less than or equal to a third preset value, then cleaning and drying the workpiece to obtain the vacuum chuck. The application can at least solve the problem that the manufacturing method of the vacuum chuck in the prior art has single welding process, and welding deformation and insufficient sealing of a welding seam occur.

Description

Technical Field

[0001] This application relates to the field of precision mechanical parts manufacturing technology, and more specifically, to a method for manufacturing a vacuum chuck. Background Technology

[0002] In related technologies, the manufacturing method of vacuum chucks employs a single welding process, which is prone to welding deformation and insufficient weld sealing, failing to meet the requirements for vacuum leak detection. Furthermore, the single welding process places stringent demands on the original machining precision of the parts, with extremely low tolerance for error. Any minute deviation or deformation beyond the acceptable range can lead to uneven material filling and the formation of leakage channels. Moreover, in the manufacturing method of vacuum chucks, the connection between the parts machining and welding processes is often unreasonable, resulting in finished product dimensions exceeding tolerance limits and insufficient dimensional and positional accuracy. Summary of the Invention

[0003] The main objective of this application is to provide a method for manufacturing a vacuum chuck, so as to solve the problems of welding deformation and insufficient weld sealing caused by the single welding process in the manufacturing method of vacuum chuck in the prior art.

[0004] According to one aspect of this application, a method for manufacturing a vacuum chuck is provided, comprising: Part processing steps: The substrate is processed to form a chuck substrate and an adsorption layer, and a vacuum channel and a suction hole communicating with the vacuum channel are processed on the chuck substrate, and multiple micropores are processed on the adsorption layer; Vacuum diffusion welding steps: The chuck substrate and the adsorption layer are surface treated, and the chuck substrate and the adsorption layer are clamped to form a workpiece to be welded. The workpiece is then placed in a vacuum diffusion welding furnace with a first predetermined vacuum degree, a first predetermined welding temperature, a first predetermined pressure and a first predetermined holding time for welding. Vacuum brazing step: The workpiece after diffusion welding is placed in a vacuum brazing furnace with a second predetermined vacuum degree, a second predetermined welding temperature, a second predetermined holding time and a predetermined cooling rate for welding; Post-processing steps: The workpiece is surface treated, and the form and position tolerances and linear dimensions of the workpiece are detected. If the form and position tolerances meet the first preset value and the linear dimensions meet the second preset value, the closed cavity formed inside the workpiece is leak-tested. If the leakage rate of the cavity is less than or equal to the third preset value, the workpiece is cleaned and dried to obtain the vacuum chuck.

[0005] Furthermore, after the vacuum diffusion welding step and before the vacuum brazing step, the method for manufacturing the vacuum chuck further includes a semi-finished product processing step, which includes: The surface of the workpiece after diffusion welding is ground, and the flatness of the reference surface of the workpiece is checked. If the flatness is less than or equal to 0.05 mm, the grinding process is completed. If the flatness is greater than 0.05 mm, the grinding process is repeated until the flatness is less than or equal to 0.05 mm.

[0006] Furthermore, in the semi-finished product processing step, the connection of the vacuum channel is precision bored, and the micropores and the weld formed after the vacuum diffusion welding are deburred.

[0007] Furthermore, in the vacuum diffusion welding step: The first predetermined vacuum degree is less than or equal to 1×10 -3 Pa; and / or, The first predetermined welding temperature includes: 400℃~700℃; and / or, The first predetermined pressure includes: 5MPa~30MPa; and / or, The first predetermined heat preservation time includes 50 min to 120 min.

[0008] Furthermore, in the vacuum brazing step: The second predetermined vacuum level is less than or equal to 5 × 10 -4 Pa; and / or, The second predetermined welding temperature includes: 500℃~700℃; and / or, The second predetermined heat preservation time includes: 30 min to 90 min; and / or, The predetermined cooling rate includes: 5℃ / min to 8℃ / min.

[0009] Furthermore, in the vacuum diffusion welding step, the surface treatment includes a degreasing process, an acid pickling process, and a drying process performed sequentially.

[0010] Furthermore, in the post-processing step, the form and position tolerances and linear dimensions of the workpiece are inspected. If at least one of the form and position tolerances or the linear dimensions does not meet the corresponding preset value, the workpiece is surface-treated again until the form and position tolerances meet the first preset value and the linear dimensions meet the second preset value. Then, the closed cavity formed inside the workpiece is leak-checked and cleaned and dried.

[0011] Furthermore, in the part processing step, the flatness of the reference surface of the chuck substrate and the flatness of the reference surface of the adsorption layer are both less than or equal to 0.05 mm; and / or, In the part processing steps, a sealing surface is provided on the outer periphery of the suction hole, and the reserved polishing allowance of the sealing surface is 0.1mm~0.2mm.

[0012] Furthermore, in the post-processing step, the surface treatment includes polishing the sealing surface along the grain, and the roughness of the sealing surface after polishing is less than or equal to 0.8 μm.

[0013] Furthermore, in the post-processing step, a helium gas chromatography leak detector is used to detect leaks in the cavities inside the workpiece; and / or, The third preset value is 1×10 -7 Pa·L / s.

[0014] In this application, a composite welding process combining vacuum diffusion welding and vacuum brazing is used to produce vacuum chucks. First, vacuum diffusion welding is used to fundamentally bond the chuck substrate and adsorption layer through interatomic diffusion, reducing major leakage channels. Then, brazing is used to fill any microscopic defects that may remain after diffusion welding. This approach not only solves the welding deformation problem that can occur when using a single welding process, but also achieves high sealing performance in the vacuum chuck, improving the stability of the adsorption force during actual use. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, are illustrative and descriptive, serving to explain this application and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic flowchart of a method for manufacturing a vacuum chuck disclosed in an embodiment of this application; Figure 2 This is a schematic diagram of the chuck substrate of a vacuum chuck prepared by a method for manufacturing a vacuum chuck disclosed in an embodiment of this application, viewed from a first perspective. Figure 3 This is a schematic diagram of the chuck substrate of a vacuum chuck prepared by a method for manufacturing a vacuum chuck disclosed in an embodiment of this application, viewed from a second perspective. Figure 4 This is a schematic diagram of the structure of a vacuum chuck prepared by a method for manufacturing a vacuum chuck disclosed in an embodiment of this application; Figure 5 This is a cross-sectional view of a vacuum chuck prepared according to a method for manufacturing a vacuum chuck disclosed in an embodiment of this application.

[0016] The above figures include the following reference numerals: 100. Vacuum chuck; 10. Chuck substrate; 11. Vacuum channel; 12. Suction hole; 13. Sealing surface; 14. Auxiliary structure; 20. Adsorption layer; 21. Micropores. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0020] As described in the background section, in related technologies, the manufacturing method of vacuum chucks employs a single welding process, which is prone to welding deformation and insufficient weld sealing, failing to meet the requirements for vacuum leak detection. Furthermore, the single welding process places stringent demands on the original machining accuracy of the parts, with extremely low tolerance; any minute dimensional deviation or deformation will result in uneven material filling, creating leakage channels. Moreover, in the manufacturing method of vacuum chucks, the connection between the part machining and welding processes is unreasonable, leading to finished product dimensional tolerances exceeding the tolerance range and insufficient dimensional and positional accuracy. Therefore, this application provides a new manufacturing method for vacuum chucks that solves the problems of welding deformation and insufficient weld sealing caused by the single welding process in existing vacuum chuck manufacturing methods. The manufacturing method of the vacuum chuck of this application will be described below with reference to the accompanying drawings.

[0021] See Figures 1 to 5 As shown in the figure, this application provides a method for manufacturing a vacuum chuck.

[0022] Specifically, the method for manufacturing the vacuum chuck provided in this application includes: Part processing steps: The substrate is processed to form a chuck substrate 10 and an adsorption layer 20, and a vacuum channel 11 and a suction hole 12 communicating with the vacuum channel 11 are processed on the chuck substrate 10. Multiple micropores 21 are processed on the adsorption layer 20.

[0023] It is understood that in this application, the chuck substrate 10 is used to support the adsorption layer 20 and provide the vacuum channel 11 to ensure overall rigidity. The adsorption layer 20 is used to contact thin workpieces (such as wafers), and is responsible for uniformly dispersing the adsorption force, preventing scratches, and adapting to different thin workpiece surfaces. Specifically, the substrate can be stainless steel, aluminum alloy, cast iron, etc. In this application, aluminum alloy is preferred as the substrate because it has the characteristics of being lightweight and having high strength, which can meet the usage requirements of the vacuum chuck 100. Of course, in some other embodiments of this application, the substrate of the adsorption layer 20 can be different from the substrate of the chuck substrate 10. The substrate of the chuck substrate 10 can be stainless steel, aluminum alloy, or engineering ceramics; the substrate of the adsorption layer 20 can be porous sintered metal, etc.

[0024] In actual processing, the aluminum alloy substrate is machined into the chuck substrate 10 and the adsorption layer 20 through turning and milling processes, respectively. During the machining process, the tolerances of the critical dimensions of the chuck substrate 10 and the adsorption layer 20 (such as the diameter of the chuck substrate 10 being 308.4 mm and the diameter of the adsorption layer 20 being 215 mm) need to meet the grade f requirements in GB / T1804-2000. Furthermore, in this application, the chuck substrate 10 and the adsorption layer 20 are designed for separate machining, which reduces the overall manufacturing difficulty.

[0025] It is worth noting that in this application, the flatness of the reference surface of the chuck substrate 10 and the flatness of the reference surface of the adsorption layer 20 are both less than or equal to 0.05 mm. For example, the flatness can be 0.05 mm, 0.04 mm, 0.03 mm, etc. When the reference surface of the chuck substrate 10 and the reference surface of the adsorption layer 20 are assembled (which can be a bolt connection, screw connection, etc.), they need to fit tightly. When the flatness of the reference surface of the chuck substrate 10 and the flatness of the reference surface of the adsorption layer 20 are both less than or equal to 0.05 mm, there is no obvious gap after assembly, which can also eliminate assembly stress, thereby avoiding deformation of the chuck substrate 10 or the adsorption layer 20 itself, and improving process reliability and yield. At the same time, this setting can significantly increase the effective contact area between the chuck substrate 10 and the adsorption layer 20, which is beneficial to improving the welding quality and weld strength of subsequent vacuum diffusion welding, and ensuring the overall flatness of the workpiece after welding, eliminating the risk of negative pressure leakage.

[0026] Furthermore, the reference surface of the adsorption layer 20 serves as the positioning reference for the processing of the micropores 21. A flatness of less than or equal to 0.05 mm ensures the stability of the clamping posture of the adsorption layer 20 on the processing equipment, guaranteeing the consistency and perpendicularity of the micropore processing. In this application, the micropores 21 on the adsorption layer 20 can be processed using CNC drilling technology. The number of micropores can be 48 groups of 5EQS (i.e., each group contains 5 micropores evenly spaced within its area) or 24 groups of 5EQS micropores, etc.

[0027] In some embodiments, after the chuck substrate 10 and the adsorption layer 20 are assembled, the micropores 21 on the adsorption layer 20 include those communicating with a vacuum channel 11, which is an air passage. In other embodiments, the micropores 21 on the adsorption layer 20 also include micropores communicating with a water channel. This water channel is used for precise temperature control of the adsorbed workpiece during the use of the vacuum chuck 100. In this application... Figures 2 to 5 The micropore 21 shown is used to connect the air passage. In actual processing, the micropore 21 adopts a flat-bottom design (i.e., it is machined using a flat-bottom drill bit). The flat-bottomed hole has no local protrusions or depressions, allowing the negative pressure to form a uniform pressure field at the bottom of the hole. This pressure is then transmitted through the opening of the micropore 21 to the contact surface of the adsorbed thin workpiece (such as a wafer), avoiding the problem of local negative pressure concentration caused by sharp / rounded bottoms, further optimizing the adsorption stability of the adsorption layer 20 for thin, fragile workpieces. Simultaneously, this design also improves the reliability of vacuum diffusion welding. The flatness of the micropore bottom avoids stress concentration at the bottom of the hole during welding, preventing localized cracking of the weld due to protrusions at the bottom of the hole, while ensuring that the connectivity between the micropore 21 and the vacuum channel 11 after welding is not affected by structural defects.

[0028] Optionally, during the part machining process, a sealing surface 13 is provided on the outer periphery of the suction hole 12, with a pre-polishing allowance of 0.1mm to 0.2mm for the sealing surface 13. It is understood that the sealing surface 13 refers to the annular plane surrounding the suction hole 12, which is used for connection with the pipe assembly (not shown in the figure) used for negative pressure extraction. During the part machining process, the sealing surface 13, after turning and milling, will have minor dimensional and positional errors (such as roundness deviation and surface waviness). The 0.1mm to 0.2mm polishing allowance can serve as error compensation space. In subsequent processing steps, the minor defects from the earlier machining can be corrected through polishing, ensuring dimensional consistency of the sealing surfaces 13 on all chuck bases 10, thereby ensuring high-precision sealing of the vacuum chuck 100 during use and preventing vacuum leakage.

[0029] Furthermore, such as Figures 2 to 5As shown, the part machining steps also include machining of auxiliary structures 14 (such as threaded holes, pin holes, etc.). The pin holes and threaded holes are used to ensure precise positioning and reliable connection in the assembly of multiple components. For example, the pin holes can be used to connect the chuck base 10 to the adsorption layer 20, and the vacuum chuck 100 to the machine tool table. The threaded holes can be used to fix the chuck base 10 and the adsorption layer 20. The machining also includes rounding / chamfering.

[0030] After the part processing steps are completed, a vacuum diffusion welding step is performed. Specifically, the vacuum diffusion welding step includes: surface treatment of the chuck substrate 10 and the adsorption layer 20, clamping the chuck substrate 10 and the adsorption layer 20 to form a workpiece to be welded, and then placing the workpiece into a vacuum diffusion welding furnace with a first predetermined vacuum degree, a first predetermined welding temperature, a first predetermined pressure and a first predetermined holding time for welding, and cooling to room temperature with the furnace after welding.

[0031] With this configuration, under high temperature, high pressure, and high vacuum conditions, the atoms on the contact surfaces of the chuck substrate 10 and the adsorption layer 20 diffuse into each other, eventually forming a metallurgical bond. The interface between the chuck substrate 10 and the adsorption layer 20 completely disappears, becoming a single unit. This greatly reduces the risk of vacuum leakage from the interface, ensuring the stability of the adsorption force. Since vacuum diffusion welding is a solid-state welding process, the welding temperature is lower than the melting point of aluminum alloys. The workpiece undergoes no melting phase transformation during welding, preventing defects such as weld spatter and weld beads. This effectively protects the vacuum channel 11, suction hole 12, sealing surface 13, and auxiliary structures 14 (such as threaded holes and pin holes) of the chuck substrate 10, while also preventing the micropores 21 on the adsorption layer 20 from being blocked by solder or deformed due to high temperature.

[0032] Specifically, in the vacuum diffusion welding process, surface treatment includes a degreasing process, a pickling process, and a drying process. The degreasing process uses organic solvents for cleaning and alkaline solution saponification to thoroughly remove organic contaminants from the bonding surface, directly exposing the metal base material of the chuck substrate 10 and the adsorption layer 20. This provides a clean, impurity-free interface for subsequent pickling and atomic diffusion, preventing defects such as porosity and inclusions in the weld due to residual oil. The pickling process removes the oxide film on the chuck substrate 10 and the adsorption layer 20. It is understood that the pickling process uses acidic solutions (such as hydrochloric acid solution, phosphoric acid-sulfuric acid mixture, etc.) to precisely dissolve the oxide film on the bonding surface without excessively corroding the aluminum alloy base material, ensuring the dimensional accuracy of the bonding surface. Simultaneously, pickling creates a uniform micro-rough texture on the metal surface, transforming the bonding surface of the chuck substrate 10 and the adsorption layer 20 from a mirror-like contact to a micro-interlocking contact, significantly increasing the effective contact area, accelerating the atomic diffusion rate, and thus improving the bonding strength and density of the weld. After the pickling process, the bonding surfaces may retain acidic solutions and moisture. If these remain directly in the vacuum diffusion welding furnace, the moisture will rapidly vaporize under the high-temperature vacuum environment. The resulting water vapor will create defects such as porosity and looseness in the weld. Simultaneously, the water vapor will cause secondary oxidation with the metal surface, negating the effects of the initial degreasing and pickling. The drying process, through hot air drying or low-temperature baking, can thoroughly remove residual moisture and acid from the bonding surfaces, ensuring the workpieces are dry and clean. This prevents weld defects caused by moisture during welding, thus guaranteeing the quality of vacuum diffusion welding.

[0033] Furthermore, after surface treatment of the chuck substrate 10 and the adsorption layer 20, the chuck substrate 10 and the adsorption layer 20 are clamped to form the workpiece to be welded. At this time, the micropores 21 on the adsorption layer 20 are connected to the vacuum channel 11 on the chuck substrate 10. Specifically, clamping fixtures such as bolts or screws can be used to clamp the two together. At this time, the clamping fixture ensures the precise alignment of the chuck substrate 10 and the adsorption layer 20, ensuring the connectivity of the negative pressure path. At the same time, it ensures the full fit of the reference surfaces of the two, avoiding the offset, blockage, or excessive local gap of the negative pressure path due to misalignment before welding. Combined with the auxiliary structures 14 such as pin holes and threaded holes processed in the early stage, zero-gap positioning can be achieved by the cooperation of the positioning pin and the pin hole during clamping, ensuring that the negative pressure can be efficiently and uniformly transmitted from the vacuum channel 11 to all micropores 21 after welding. Meanwhile, since atomic diffusion in vacuum diffusion welding requires a certain pressure to fully occur, the clamping fixture can apply a uniform preload to the mating surfaces, forcibly eliminating the microscopic gaps between the chuck substrate 10 and the adsorption layer 20, ensuring tight contact between the metal surfaces of the two parts. The uniform clamping force ensures consistent atomic diffusion rates across all areas of the mating surfaces, preventing incomplete penetration defects caused by insufficient local pressure or component deformation due to excessive local pressure, ultimately forming a dense and uniform weld and eliminating the risk of negative pressure leakage at its source. Furthermore, the clamping fixture can also constrain the deformation of the chuck substrate 10 and the adsorption layer 20 during the vacuum diffusion welding process, maintaining precise dimensional accuracy.

[0034] Furthermore, in the vacuum diffusion welding step: the vacuum degree of the vacuum diffusion welding furnace is less than or equal to 1×10⁻⁶. -3 Pa. At this vacuum level, impurities such as oxygen and water vapor in the vacuum diffusion welding furnace can be completely removed, eliminating oxidation interference and ensuring a pure and dense weld.

[0035] Furthermore, in the vacuum diffusion welding step: the first predetermined welding temperature includes 400℃~700℃. For example, the first predetermined welding temperature can be 400℃, 500℃, 600℃, and 700℃, etc. When the first welding temperature is within the above range, the lower limit of 400℃ can activate the diffusion kinetic energy of aluminum alloy atoms, causing the atoms on the bonding surface to interpenetrate and meet the weld strength requirements. The upper limit of 700℃ is close to but does not exceed the melting point of aluminum alloy, avoiding melting phase transformation of the workpiece and preventing the precision structures such as the vacuum channel 11, suction hole 12, sealing surface 13 of the chuck substrate 10, and micropores 21 of the adsorption layer 20 from failing due to melting, deformation, or collapse. That is to say, when the first predetermined welding temperature is within the above range, solid-phase diffusion can be achieved and the integrity of the precision structure can be protected.

[0036] Furthermore, in the vacuum diffusion welding step: the first predetermined pressure includes 5MPa to 30MPa. For example, the first predetermined pressure can be 5MPa, 10MPa, 20MPa, 30MPa, etc. When the first predetermined pressure is within the above range, a uniform and controllable clamping force can be applied to the bonding surface between the chuck substrate 10 and the adsorption layer 20, forcibly eliminating the micro gaps caused by processing errors, so that the metal surface of the chuck substrate 10 and the adsorption layer 20 can achieve atomic-level close contact, greatly increasing the effective diffusion area.

[0037] Furthermore, in the vacuum diffusion welding step, the first predetermined holding time includes 50 min to 120 min. For example, the first predetermined holding time can be 50 min, 70 min, 100 min, 120 min, etc. When the first predetermined holding time is within the above range, sufficient atomic diffusion can be ensured, so that the weld strength is consistent with the base material strength.

[0038] In other words, in the actual vacuum diffusion welding process, by matching the vacuum degree, welding temperature, pressure and holding time, not only is the integrity of the precision structure on the workpiece protected, but also a high-strength, zero-leakage and high-reliability metallurgical connection is achieved.

[0039] After the vacuum diffusion welding step, the workpiece, under the high temperature and high pressure environment of vacuum diffusion welding, will still undergo slight thermoplastic deformation even with clamping fixtures. This may cause the flatness of the reference surface between the chuck substrate 10 and the adsorption layer 20 to exceed the design requirement of less than or equal to 0.05 mm. Therefore, this application adds a semi-finished product processing step after the vacuum diffusion welding step and before the vacuum brazing step. This semi-finished product processing step includes: grinding the surface of the diffusion-welded workpiece and checking the flatness of the reference surface of the workpiece. If the flatness is less than or equal to 0.05 mm, the grinding process is completed; if the flatness is greater than 0.05 mm, the grinding process is repeated until the flatness is less than or equal to 0.05 mm. Specifically, the grinding process is performed using a surface grinder.

[0040] Understandably, grinding can remove defects such as protrusions and warping from the datum surface after welding through precision grinding. Combined with a closed-loop system of inspection-grinding-re-inspection, this ensures that the flatness of the datum surface remains stable and meets standards, restoring the precision dimensional accuracy before diffusion welding and avoiding the impact of welding deformation on subsequent processes and the performance of the final product. Simultaneously, grinding provides an absolutely flat and reliable assembly datum surface for vacuum brazing, ensuring the assembly accuracy and sealing of subsequent vacuum brazing.

[0041] Furthermore, in the semi-finished product processing step, the connecting parts of the vacuum channel 11 are precision bored, and the microholes 21 and the welds formed after vacuum diffusion welding are deburred. At the same time, auxiliary holes that are blocked by diffusion welding can also be machined in this step.

[0042] During vacuum diffusion welding, the high temperature and high pressure environment can cause slight deformation at the connection points between the vacuum channel 11, the suction hole 12, and the micropores 21 on the adsorption layer 20. If the dimensions of the connection points are irregular, it will increase the flow resistance of the negative pressure in the channel, resulting in uneven distribution of negative pressure. Precision boring can accurately correct the inner diameter and coaxiality of the connection points, making the vacuum channel 11, suction hole 12, and micropores 21 form a smooth and unobstructed integrated negative pressure path. This ensures that the negative pressure generated by the external vacuum system can be quickly and losslessly transmitted to all micropores 21, avoiding the attenuation of adsorption force due to local channel narrowing, and improving the negative pressure response speed.

[0043] Meanwhile, during vacuum diffusion welding and the initial micro-hole processing, impurities such as burrs and welding slag are easily left on the inner wall of the micro-holes 21. These burrs can reduce the effective pore size of the micro-holes 21, or even completely block some of them, leading to uneven negative pressure distribution on the surface of the adsorption layer 20. This can result in problems such as insufficient local adsorption force, workpiece positioning misalignment, excessive local adsorption force, and deformation of thin-walled workpieces. After removing the burrs, the inner wall of the micro-holes 21 becomes smooth and unobstructed, and the effective pore size of all micro-holes 21 becomes consistent. The negative pressure can then be applied evenly to the contact surface of thin-film workpieces (such as wafers), significantly improving adsorption stability and reducing the risk of long-term blockage caused by impurity accumulation in the micro-holes 21. Furthermore, the weld surface formed by diffusion welding may have protruding burrs. On the one hand, these burrs can disrupt the flatness of the fit between the chuck substrate 10 and the reference surface of the adsorption layer 20, leading to tiny gaps during subsequent assembly or vacuum brazing, which can become a potential source of negative pressure leakage. On the other hand, sharp burrs are stress concentration sources. Under long-term cutting force and negative pressure impact, micro-cracks are easily generated at the root of the burrs, which in turn leads to weld cracking, reducing the structural strength and service life of the vacuum chuck 100. After removing the weld burrs, the weld surface is smooth and flat, which not only ensures the fitting accuracy of the reference surface and eliminates negative pressure leakage, but also eliminates the risk of stress concentration, strengthens the fatigue resistance of the weld, and extends the service life of the vacuum chuck 100.

[0044] Specifically, in this application, burrs can be removed using a scouring pad, scraper, or small grinder. After burrs are removed, the workpiece is ultrasonically cleaned to prevent impurities from remaining on the workpiece, affecting the conductivity of the air passage, and laying the foundation for subsequent vacuum brazing.

[0045] In other words, this application incorporates a semi-finished product processing step between the vacuum diffusion welding step and the vacuum brazing step. Through grinding, deburring, and ultrasonic cleaning, a high-precision and high-cleanliness welding interface is provided for vacuum brazing. Furthermore, finishing before brazing is more reliable than finishing after brazing, which helps ensure the flatness and adsorption performance of the final product.

[0046] Although vacuum diffusion welding achieves an integral metallurgical bond between the chuck substrate 10 and the adsorption layer 20, due to microscopic unevenness of the materials, differences in cleanliness, or fluctuations in process parameters between the chuck substrate 10 and the adsorption layer 20, extremely small, incompletely closed pores or areas of incomplete bonding may still exist at the local edges or microscopic defects of the diffusion weld. Therefore, after the workpiece has completed the semi-finished product processing steps following diffusion welding, the workpiece is re-clamped and placed in a vacuum brazing furnace for brazing.

[0047] Specifically, the vacuum brazing step includes: placing the workpiece after diffusion welding into a vacuum brazing furnace with a second predetermined vacuum level, a second predetermined welding temperature, a second predetermined holding time, and a predetermined cooling rate for welding. In the vacuum brazing step, a filler metal compatible with the base material is selected, ensuring that their coefficients of thermal expansion are similar, greatly reducing thermal stress caused by uneven shrinkage during cooling after welding. Simultaneously, the filler metal and base material are metallurgically bonded, resulting in a high joint strength.

[0048] It is understandable that after the semi-finished product processing step is completed, the excellent fluidity and capillary action of the molten aluminum-based brazing filler metal are utilized as a liquid sealant to specifically fill and seal microscopic pores, interface defects, and tiny gaps at the weld edge that may exist in diffusion welding. The combination of diffusion welding and brazing enhances the structural strength of the vacuum chuck 100 and achieves high sealing performance. Specifically, before vacuum brazing, the semi-finished product is placed in a vacuum brazing furnace, and the brazing filler metal is processed into a shape corresponding to the weld and precisely adhered to the weld surface. For example, if the weld is annular, the brazing filler metal can be made into annular sheets; if the weld is linear, the brazing filler metal can be cut into strips and evenly laid along the length of the weld. Of course, in other embodiments of this application, shallow pre-reserved grooves can be designed in advance at the edge of the diffusion weld during the part processing step, allowing the brazing filler metal to be embedded in the grooves. This application does not limit the specific method of brazing filler metal placement; it can be selected according to actual needs.

[0049] Furthermore, in the vacuum brazing step: the vacuum degree of the vacuum brazing furnace is less than or equal to 5 × 10⁻⁶. -4 Pa. When the vacuum level is within the above range, an ultrapure reaction environment can be created, which can reduce the surface tension of aluminum-based brazing filler metal, optimize its fluidity and capillary penetration ability, and thus enable it to penetrate and diffuse into any microscopic discontinuities that may exist after soldering.

[0050] Furthermore, in the vacuum brazing step, the second predetermined welding temperature includes 500℃ to 700℃. For example, the second predetermined welding temperature can be 500℃, 600℃, and 700℃, etc. When the second predetermined welding temperature meets the above range, it can adapt to the melting point of the brazing filler metal and protect the diffusion weld seam and prevent precision structures such as micro-hole 21, vacuum channel 11, and sealing surface 13 from deformation or collapse due to overheating.

[0051] Furthermore, in the vacuum brazing step, the second predetermined holding time includes 30 min to 90 min. For example, the second predetermined holding time can be 30 min, 60 min, 90 min, etc. When the second predetermined holding time is within the above range, it ensures that the brazing filler metal completes its flow, filling, spreading, and undergoes the necessary interfacial diffusion with the workpiece. Compared to the holding time in vacuum diffusion welding, vacuum brazing has a shorter time, which reduces the impact of high temperature on the substrate properties, balancing reinforcement effect and processing efficiency.

[0052] Furthermore, in the vacuum brazing step, the predetermined cooling rate includes 5℃ / min to 8℃ / min. For example, the predetermined cooling rate can be 5℃ / min, 6℃ / min, 8℃ / min, etc. When the cooling rate is within the above range, this cooling rate represents a controllable, slow cooling range, adapting to the thermal expansion characteristics of aluminum alloys and enabling slow, uniform cooling to control deformation and stress, maintaining accuracy. Simultaneously, uniform cooling can control the overall deformation of the chuck, ensuring that the flatness of the reference surface remains within the requirement of less than or equal to 0.05mm, eliminating the need for subsequent secondary shaping and directly meeting the finished product assembly standards.

[0053] After the vacuum brazing step is completed, the resulting workpiece undergoes post-processing. Specifically, the post-processing steps include: surface treatment of the workpiece, and inspection of its form and position tolerances and linear dimensions. If the form and position tolerances meet a first preset value and the linear dimensions meet a second preset value, then the closed cavity formed inside the workpiece is leak-tested. If the leakage rate of the cavity is less than or equal to a third preset value, then the workpiece is cleaned and dried to obtain the vacuum chuck 100. If, during the inspection of the form and position tolerances and linear dimensions of the workpiece, at least one of the form and position tolerances or linear dimensions does not meet the corresponding preset value, then the workpiece undergoes surface treatment again until the form and position tolerances meet the first preset value and the linear dimensions meet the second preset value. Finally, the closed cavity formed inside the workpiece is leak-tested and cleaned and dried.

[0054] Geometric tolerances include form tolerances, positional tolerances, and form or positional tolerances. Geometric tolerances include straightness, flatness, etc. In this application, geometric tolerances mainly refer to flatness. Flatness meets a first preset value, i.e., flatness less than or equal to 0.05 mm (i.e., meets GB / T1184-1996-H grade requirements). Linear dimensions, i.e., length, diameter, radius, etc., meet a second preset value, which meets GB / T1804-2000-f grade requirements.

[0055] Furthermore, the surface treatment in the post-processing steps mainly involves polishing the sealing surface 13 along the grain (i.e., maintaining a consistent direction during polishing). After polishing, the roughness of the sealing surface 13 is less than or equal to 0.8 μm. It is understandable that the sealing surface 13 is the last line of defense for the vacuum performance of the vacuum chuck 100, and its surface quality requirements are the highest. If the surface of the sealing surface 13 has microscopic scratches, pits, or excessive roughness, leakage channels may form. Even if the weld is highly dense after welding, it can still lead to system failure. Other areas do not require high smoothness. For example, the function of the adsorption surface of the adsorption layer 20 is uniform permeable adsorption, not sealing or sliding. If its surface is excessively polished, it may clog the micropores 21, reduce the surface friction coefficient, cause the thin workpiece to slip during processing, and increase unnecessary costs and process risks. The other surfaces of the chuck substrate 10, except for the sealing surface 13, only serve a structural support or mounting function and have no direct impact on vacuum performance or adsorption performance. Excessive polishing increases production costs and reduces production efficiency.

[0056] Specific surface treatments (such as precision polishing) on ​​the sealing surface 13 can precisely remove the aforementioned defects, reducing the surface roughness of the sealing surface 13 to sealing-grade precision. This ensures an atomically tight fit between the sealing surface 13 and the pipe joint, completely eliminating microscopic gaps. Combined with subsequent leak detection procedures, this ensures that the sealing surface 13 has no hidden leaks under high vacuum conditions, guaranteeing efficient transmission of negative pressure from the external pipe to the vacuum channel 11. However, the high-temperature environment of vacuum brazing may cause slight thermal deformation of the sealing surface 13, causing its dimensional accuracy to deviate from design requirements.

[0057] Furthermore, in this application, the polishing of the sealing surface 13 employs parallel-grain polishing, which allows the sealing surface 13 to form fine textures in a consistent direction. This parallel-grain structure is more easily filled by the clamping force when it fits against the end face of the external pipe structure, eliminating microscopic gaps. Simultaneously, a roughness of ≤0.8μm is considered a precision surface finish for sealing applications, allowing the sealing surface 13 to achieve a high degree of fit with the pipe joint. Combined with metal hard seals or sealing rings, this completely blocks the leakage path of negative pressure from the interface, ensuring the stability of the negative pressure within the vacuum channel 11 and avoiding potential leakage hazards caused by microscopic protrusions on the sealing surface 13. In addition, the vacuum chuck 100 requires frequent disassembly and assembly of the external suction pipe during maintenance and repair, causing the sealing surface 13 to repeatedly rub against the end face of the joint. The surface texture of the parallel-polished surface aligns with the friction direction during assembly and disassembly, significantly reducing frictional resistance and minimizing surface scratches. The smooth surface with a roughness ≤0.8μm avoids wear caused by sharp protrusions, ensuring the sealing surface 13 maintains its original flatness and sealing performance even after multiple assembly and disassembly processes. This significantly extends the service life of the sealing surface 13 and reduces maintenance and replacement costs. Furthermore, a polishing allowance of 0.1mm~0.2mm is provided for the sealing surface 13 during the component machining process, ensuring a high-precision seal for the vacuum chuck 100 during use and preventing vacuum leakage.

[0058] Furthermore, in the post-processing step, a helium gas chromatography-mass spectrometry leak detector is used to detect leaks in the internal cavity of the workpiece, with a third preset value of 1×10⁻⁶. -7 Pa·L / s. Helium mass spectrometry leak detectors are the most sensitive leak detection devices in the vacuum field. Their detection principle utilizes the small molecular weight of helium, which allows it to easily penetrate tiny gaps, enabling them to detect nanoscale micro-leakage that conventional leak detection methods cannot identify (such as hidden micropores in diffusion welds, microscopic cracks in brazed layers, and nanoscale gaps in sealing surfaces 13). 1×10 - 7 The leakage rate threshold of Pa·L / s belongs to the ultra-high vacuum sealing level, which can ensure that the closed cavity of the vacuum chuck 100 (the cavity connecting the vacuum channel 11, the suction hole 12, and the micropore 21) is in a near-zero leakage state, completely eliminating the problem of slow negative pressure decay caused by hidden micro-leakage. This setting can also match the high negative pressure conditions of the vacuum chuck 100, ensuring long-term stability of the adsorption force.

[0059] Furthermore, after the leak detection is passed, the workpiece is cleaned using an ultrasonic cleaning process and then dried, which can remove the impurities remaining during the processing.

[0060] To verify the technical effects of this application, the following specific embodiments are provided: Example 1 Part machining steps: Select 6-series aluminum alloy bar and turn it to a chuck base 10 with an outer diameter of 320mm and an adsorption layer 20 with an outer diameter of 215mm; mill the reference surface, and control the flatness to 0.03mm; use a CNC drilling machine to machine 48 sets of 5EQS micro-holes (through to vacuum channel 11) and 9 sets of 5EQS micro-holes (through to vacuum channel 11), with a micro-hole flat bottom depth of 31.1mm for the air passage; machine M16×1.5 threaded holes (bottom hole depth 26mm, flat bottom not drilled through), M6×1.5 threaded holes and pin holes, leave a 0.2mm polishing allowance on the sealing surface 13, and machine the fillet to R0.25.

[0061] Vacuum diffusion welding steps: After degreasing (acetone ultrasonic cleaning for 10-15 minutes), pickling (immersion in 5% hydrochloric acid solution for 5-15 minutes), and drying (oven drying at 120°C for 30 minutes) of the chuck substrate 10 and adsorption layer 20, the chuck substrate 10 and adsorption layer 20 are assembled and clamped to form the workpiece to be welded; the parameters of the vacuum diffusion welding furnace are set as follows: vacuum degree 1×10 -4 The welding temperature is 500℃~700℃, the pressure is 10MPa~25MPa, the holding time is 90min, and the furnace is cooled to room temperature.

[0062] Semi-finished product processing steps: Use a surface grinder to grind the reference surface and correct the flatness to 0.01mm; precision bore the inner diameter of the vacuum channel 11 to ensure that the vacuum channel 11 and the microhole 21 are connected; after mechanical deburring and ultrasonic cleaning (40kHz / 20min), rinse with clean water and dry.

[0063] Vacuum brazing steps: Select Al-Si brazing filler metal and evenly spread it along the weld seam; set the vacuum brazing furnace parameters as follows: vacuum degree 1×10⁻⁶. -4 Pa, welding temperature is 500℃~700℃, holding time is 35min, cooling rate is 6℃ / min~10℃ / min.

[0064] Post-processing steps: Polish the sealing surface 13 along the grain to Ra=0.6μm; test linear dimensions according to GB / T1804-2000-f grade, and test geometric tolerances (flatness) according to GB / T1184-1996-H grade; test the leakage rate with a mass spectrometer leak detector to 8×10⁻⁶. -4 Pa L / s, meets the requirements; after ultrasonic cleaning (60℃ / 15min), dry and put the finished product into storage.

[0065] The test results after following the above steps are as follows:

[0066] Comparative Example 1 In this embodiment, the steps are basically the same as in Embodiment 1. The difference is that in this embodiment, the vacuum diffusion welding is directly followed by a post-processing step (i.e., the semi-finished product processing step and the vacuum brazing step are missing). The test results are as follows:

[0067] Comparative Example 2 In this embodiment, the steps are basically the same as in Embodiment 1. The difference is that in this embodiment, vacuum brazing is performed after the part processing steps are completed, followed by a post-processing step (i.e., the vacuum diffusion welding step and the semi-finished product processing step are missing). The test results are as follows:

[0068] Comparative Example 3 In this embodiment, the steps are basically the same as in Embodiment 1. The difference is that, after the part processing steps are completed, a vacuum diffusion welding step is performed, followed by vacuum brazing and post-processing steps (i.e., the semi-finished product processing step is missing). The test results are as follows:

[0069] By comparing Example 1 and Comparative Example 1, it can be seen that in Example 1, the vacuum chuck 100 was prepared by sequentially employing parts processing steps, vacuum diffusion welding steps, semi-finished product processing steps, vacuum brazing steps, and post-processing steps. The resulting vacuum chuck 100 met the target values ​​for flatness, linear dimensional tolerance, and leakage rate. However, in Comparative Example 1, the final post-processing step was performed directly after the vacuum diffusion welding step without correcting the reference surface or compensating for micro-gap through brazing. This resulted in the final vacuum chuck 100 failing to meet the corresponding target values ​​for flatness, linear dimensional tolerance, and leakage rate. In other words, in the actual preparation of the vacuum chuck 100, vacuum diffusion welding alone cannot guarantee the high precision and high airtightness of the vacuum chuck 100. The thermal deformation and micro-assembly errors after vacuum diffusion welding must be corrected through semi-finished product finishing and supplemented by brazing sealing to meet the requirements of a high-end vacuum chuck 100.

[0070] By comparing Example 1 and Comparative Example 2, it can be seen that Comparative Example 2 uses a single vacuum brazing process, without vacuum diffusion welding as a substrate connection, and without any semi-finished product processing to correct deformation. The flatness, linear dimensional tolerance, and leakage rate of the vacuum chuck 100 prepared in Comparative Example 2 do not meet the corresponding target values. This can be understood as brazing alone only forming a surface connection, failing to achieve atomic-level diffusion bonding, ultimately resulting in insufficient structural strength, large thermal deformation, and a high leakage rate in the prepared vacuum chuck 100. In other words, in the process of preparing the vacuum chuck 100, vacuum diffusion welding is the core process for achieving a reliable connection between the chuck substrate 10 and the adsorption layer 20, and cannot be replaced by vacuum brazing.

[0071] By comparing Example 1 and Comparative Example 3, it can be seen that Example 1 uses a precision reference surface and fine boring of the channel after the vacuum diffusion welding step to ensure geometric accuracy before vacuum brazing. However, Comparative Example 3 directly uses vacuum brazing after vacuum diffusion welding without correcting for plane warping caused by the welding process. The vacuum brazing step cannot remove existing macroscopic deformations. Even if the vacuum brazing partially compensates for micro-gaps, the lack of fine boring of the channel leads to poor connection between the micro-hole and the vacuum chamber, resulting in residual leakage. In other words, even with a composite welding process, the advantages of the composite process cannot be fully realized without intermediate finishing. Therefore, semi-finished product processing is a crucial bridge connecting a strong structure and high sealing performance.

[0072] By comparing Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3, it can be seen that: If the semi-finished product processing step is missing during the preparation of the vacuum chuck 100, the flatness of the vacuum chuck 100 exceeds the limit, the leakage rate is close to the limit, and the prepared vacuum chuck 100 is barely usable but unreliable. If the vacuum diffusion welding and semi-finished product processing steps are missing, the prepared vacuum chuck 100 has a weak structure, poor precision, and serious leakage, failing to meet the requirements of the vacuum chuck 100. If the semi-finished product processing step and the vacuum brazing step are missing, the prepared vacuum chuck 100 has large deformation and high leakage, also failing to meet the requirements of the vacuum chuck 100.

[0073] In summary, vacuum diffusion welding in composite welding provides a high-strength, high-rigidity skeleton, achieving an integral metallurgical bond between the chuck substrate 10 and the adsorption layer 20. Vacuum brazing serves as repair and reinforcement, sealing any microscopic defects that may remain after vacuum diffusion welding, thus achieving double sealing protection. Composite welding is a necessary condition for achieving a high-strength, high-sealing connection in the vacuum chuck 100; a single welding method cannot meet the requirements. The semi-finished product processing step between the two welding processes is a crucial intermediate step to ensure the dimensional accuracy, flatness, and sealing performance of the vacuum chuck 100; its absence would lead to a significant decrease in product performance. In other words, the vacuum chuck 100 adopts a composite process route of "parts processing + vacuum diffusion welding + semi-finished product processing + vacuum brazing," achieving high flatness (≤0.05mm), high dimensional stability (±0.2mm), and ultra-high vacuum sealing performance (≤1×10⁻⁶). -7 The necessary technical path (Pa·L / s).

[0074] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects: In the method for manufacturing a vacuum chuck, this application uses an aluminum alloy substrate and combines a composite welding process of vacuum diffusion welding and vacuum brazing. A semi-finished product processing step is added after vacuum diffusion welding and before vacuum brazing. This design not only solves the welding deformation problem of the vacuum chuck 100 caused by using a single welding process, but also achieves high sealing performance of the vacuum chuck 100, improving the stability of the suction force of the vacuum chuck 100 during actual use.

[0075] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0076] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0077] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a vacuum chuck, characterized in that, include: Part processing steps: The substrate is processed to form a chuck substrate (10) and an adsorption layer (20), and a vacuum channel (11) and a suction hole (12) communicating with the vacuum channel (11) are processed on the chuck substrate (10), and multiple micropores (21) are processed on the adsorption layer (20). Vacuum diffusion welding steps: The chuck substrate (10) and the adsorption layer (20) are surface treated, and the chuck substrate (10) and the adsorption layer (20) are clamped to form a workpiece to be welded. Then the workpiece is placed in a vacuum diffusion welding furnace with a first predetermined vacuum degree, a first predetermined welding temperature, a first predetermined pressure and a first predetermined holding time for welding. Vacuum brazing step: The workpiece after diffusion welding is placed in a vacuum brazing furnace with a second predetermined vacuum degree, a second predetermined welding temperature, a second predetermined holding time and a predetermined cooling rate for welding; Post-processing steps: The workpiece is surface treated, and the form and position tolerances and linear dimensions of the workpiece are detected. If the form and position tolerances meet the first preset value and the linear dimensions meet the second preset value, the closed cavity formed inside the workpiece is leak-tested. If the leakage rate of the cavity is less than or equal to the third preset value, the workpiece is cleaned and dried to obtain the vacuum chuck (100).

2. The method for manufacturing a vacuum chuck according to claim 1, characterized in that, After the vacuum diffusion welding step and before the vacuum brazing step, the manufacturing method of the vacuum chuck (100) further includes a semi-finished product processing step, which includes: The surface of the workpiece after diffusion welding is ground, and the flatness of the reference surface of the workpiece is checked. If the flatness is less than or equal to 0.05 mm, the grinding process is completed. If the flatness is greater than 0.05 mm, the grinding process is repeated until the flatness is less than or equal to 0.05 mm.

3. The method for manufacturing a vacuum chuck according to claim 2, characterized in that, In the semi-finished product processing step, the connection of the vacuum channel (11) is precision bored, and the micropores (21) and the weld formed after the vacuum diffusion welding are deburred.

4. The method for manufacturing a vacuum chuck according to claim 1, characterized in that, In the vacuum diffusion welding step: The first predetermined vacuum degree is less than or equal to 1×10 -3 Pa; And / or, The first predetermined welding temperature includes: 400℃~700℃; and / or, The first predetermined pressure includes: 5MPa~30MPa; and / or, The first predetermined heat preservation time includes 50 min to 120 min.

5. The method for manufacturing a vacuum chuck according to claim 1, characterized in that, In the vacuum brazing step: The second predetermined vacuum level is less than or equal to 5 × 10 -4 Pa; And / or, The second predetermined welding temperature includes: 500℃~700℃; and / or, The second predetermined heat preservation time includes: 30 min to 90 min; and / or, The predetermined cooling rate includes: 5℃ / min to 8℃ / min.

6. The method for manufacturing a vacuum chuck according to claim 1, characterized in that, In the vacuum diffusion welding step, the surface treatment includes a degreasing process, an acid pickling process, and a drying process in sequence.

7. The method for manufacturing a vacuum chuck according to claim 1, characterized in that, In the post-processing step, the form and position tolerances and linear dimensions of the workpiece are inspected. If at least one of the form and position tolerances or the linear dimensions does not meet the corresponding preset value, the workpiece is surface-treated again until the form and position tolerances meet the first preset value and the linear dimensions meet the second preset value. Then, the closed cavity formed inside the workpiece is leak-checked and cleaned and dried.

8. The method for manufacturing a vacuum chuck according to claim 1, characterized in that, In the part processing steps, the flatness of the reference surface of the chuck substrate (10) and the flatness of the reference surface of the adsorption layer (20) are both less than or equal to 0.05 mm; and / or, In the part processing steps, a sealing surface (13) is provided on the outer periphery of the suction hole (12), and the reserved polishing allowance of the sealing surface (13) is 0.1mm~0.2mm.

9. The method for manufacturing a vacuum chuck according to claim 8, characterized in that, In the post-processing step, the surface treatment includes polishing the sealing surface (13) along the grain, and the roughness of the sealing surface (13) after polishing is less than or equal to 0.8 μm.

10. A method for manufacturing a vacuum chuck according to any one of claims 1 to 9, characterized in that, In the post-processing step, a helium gas spectrometer leak detector is used to detect leaks in the cavities inside the workpiece; and / or, The third preset value is 1×10 -7 Pa·L / s.

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