A vacuum adsorption stage for ultra-thin circuit boards

Abstract

This utility model relates to a vacuum adsorption stage for ultra-thin circuit boards, comprising a base frame, a pressure equalizing plate, and a support fixture. The base frame includes a grid structure formed by connecting hollow transverse and longitudinal members, with a negative pressure flow channel formed inside the grid structure, and multiple first negative pressure holes on its upper surface. The pressure equalizing plate is mounted on the base frame and has second negative pressure holes. The support fixture is used to support the circuit board and position it on the pressure equalizing plate, and has third negative pressure holes. The base frame, pressure equalizing plate, support fixture, first sealing member, and second sealing member are configured to form a sealed negative pressure chamber together with the circuit board. This utility model provides a vacuum adsorption stage for ultra-thin circuit boards, which, through multi-stage negative pressure transmission, can effectively suppress the deformation of ultra-thin circuit boards during the printing process and improve the flatness and accuracy of solder paste printing.

Description

Technical Field

[0001] This utility model relates to the field of surface mount technology, specifically to a vacuum adsorption stage for ultra-thin circuit boards. Background Technology

[0002] In the field of surface mount technology, especially in high-density fine-pitch printing processes, high demands are placed on the flatness control of circuit board support devices. When processing thin circuit boards, they are prone to deformation during the printing process due to external forces or internal stresses. This deformation affects the uniformity of solder paste printing and alignment accuracy. Existing commonly used support fixtures mostly adopt solid plates or simple frame structures. While providing basic support, they often struggle to achieve a uniform distribution of adsorption force, leaving room for improvement in suppressing local warping or overall sagging of thin circuit boards. Some platforms with vacuum adsorption capabilities typically have a relatively direct negative pressure transmission path, which may result in an uneven distribution of adsorption force acting on the back of the circuit board, thus affecting the effective control of circuit board deformation. Utility Model Content

[0003] In view of this, the present invention provides a vacuum adsorption stage for ultra-thin circuit boards. The adsorption stage, through multi-stage negative pressure transmission, can effectively suppress the deformation of ultra-thin circuit boards during the printing process and improve the flatness and accuracy of solder paste printing.

[0004] The objective of this utility model is achieved through the following technical solution: A vacuum adsorption stage for ultra-thin circuit boards includes a base frame, a pressure equalizing plate, and a support fixture. The base frame includes a grid structure formed by connecting hollow transverse members and hollow longitudinal members, with a negative pressure flow channel formed inside the grid structure, and a plurality of first negative pressure holes provided on its upper surface. The pressure equalizing plate is mounted on the base frame and has second negative pressure holes. The support fixture is used to support the circuit board and position it on the pressure equalizing plate, and has third negative pressure holes. A first sealing member is provided between the pressure equalizing plate and the base frame. A second sealing member is provided between the support fixture and the pressure equalizing plate and / or between the support fixture and the circuit board. The base frame, pressure equalizing plate, support fixture, first sealing member, and second sealing member are configured to form a sealed negative pressure chamber together with the circuit board.

[0005] This three-layer structure utilizes a modular design to create a stable negative pressure system. The hollow mesh structure of the base frame provides rigid support, while its internal flow channels act as the main distribution channels, guiding negative pressure to a larger area. The equalizing plate acts as a conduit, initially equalizing and diffusing the negative pressure. The support fixture, through its dense network of negative pressure holes, ultimately applies the adsorption force to the back of the circuit board. This step-by-step transfer path effectively avoids uneven negative pressure, providing a large-area, gentle adsorption force for the ultra-thin circuit board, significantly improving the control over the board's flatness, overcoming deformation problems that may result from localized stress, and laying a solid foundation for subsequent high-precision printing. The entire device has a clear structure, with all components working collaboratively to achieve reliable fixation.

[0006] Preferably, the number of third negative pressure holes on the support fixture is much greater than the number of first negative pressure holes on the base frame.

[0007] This quantitative difference constructs a sophisticated system from macroscopic distribution to microscopic effect. Fewer negative pressure holes in the base frame are responsible for delivering negative pressure, while a much denser array of negative pressure holes in the fixture distributes the negative pressure across numerous contact points. This increases the continuity and uniformity of the adsorption force distribution, eliminating weak support points caused by insufficient adsorption points and preventing localized warping of the circuit board. For large-area or ultra-thin circuit boards, this layout provides a stable support effect with near-surface contact, enhancing the ability to suppress deformation and the operational stability of the system.

[0008] Preferably, the upper surface of the support fixture is provided with a positioning groove for positioning the circuit board. The positioning groove is surrounded by a positioning flange, and the shape of the positioning flange is adapted to the shape and size of the circuit board.

[0009] The positioning groove and flange structure provide a fast and accurate mechanical positioning reference for the circuit board. Its shape matches the circuit board contour, facilitating accurate embedding, reducing alignment time, and improving efficiency. This mechanism not only ensures horizontal positioning accuracy but, more importantly, provides vertical positioning and restraint for the ultra-thin circuit board, effectively limiting lateral slippage or rotation. This combination of physical restraint and vacuum adsorption creates a dual constraint on the circuit board in both the horizontal and vertical directions, providing a reliable positional guarantee for high-precision subsequent printing.

[0010] Preferably, the third negative pressure hole is distributed in the internal and external areas of the positioning groove.

[0011] By distributing negative pressure holes both inside and outside the positioning groove, full coverage of the circuit board adsorption area is achieved. The holes in the inner area directly adsorb the circuit board body, providing the main adsorption force. The holes in the outer area effectively constrain the easily warped edge areas. This indiscriminate, full-area adsorption support ensures sufficient negative pressure from the center to the edge, eliminating adsorption gaps, more effectively balancing internal stress, preventing edge warping, ensuring a tight overall adhesion of the circuit board, and providing a flatter and more stable working surface.

[0012] Preferably, electromagnetic locking components are provided at the four corners of the bottom of the base frame, and the bottom surface of the electromagnetic locking components does not extend beyond the bottom surface of the equalizing plate.

[0013] The four-corner electromagnetic locking components provide a quick, stable, and non-invasive installation method. Electromagnetic force instantly locks the adsorption table to the work platform, avoiding the cumbersome process of complex mechanical fastening and facilitating rapid line changes and maintenance. The design of the locking components' bottom surface not protruding from the pressure equalizing plate ensures the stability of the adsorption table and avoids the risk of scratches or interference to the precision table surface caused by protrusions, demonstrating the safety and user-friendliness of the integrated equipment.

[0014] Preferably, the base frame is provided with multiple negative pressure ports, all of which are connected to the negative pressure flow channel.

[0015] Multiple negative pressure interfaces create a multi-point negative pressure supply system. This accelerates the establishment of negative pressure within the large frame, shortening preparation time. Simultaneously, it helps maintain dynamic pressure equilibrium throughout the entire negative pressure channel, preventing insufficient negative pressure at the far end of the channel due to a single air inlet. The balanced supply provides a stable and consistent pressure source upstream, ensuring the uniformity of the final adsorption force from the system's source and consolidating the effectiveness of deformation suppression.

[0016] Preferably, the first sealing component is an O-ring or a silicone gasket.

[0017] This brings significant synergistic advantages. First, both types of seals are industrial standard parts, inexpensive, easy to procure and replace, greatly improving the maintainability and economy of the equipment. Second, they possess excellent elasticity and compression set, enabling them to form a stable, reliable, and long-life static seal between the equalizing plate and the base frame, effectively preventing negative pressure leakage and providing a fundamental guarantee for the establishment and maintenance of the core negative pressure chamber. Finally, O-rings are suitable for groove sealing, while silicone gaskets are more suitable for planar sealing. This limitation provides a clear and mature implementation path for manufacturing requirements with different precision and cost, ensuring the feasibility and optimization of the sealing solution of this utility model.

[0018] Preferably, the supporting fixture is a frame structure with a hollowed-out window.

[0019] The frame structure with perforated windows optimizes the physical properties of the fixture while ensuring its overall structural strength. The perforated design significantly reduces the fixture's weight, facilitating handling and transportation, and improving fixture replacement efficiency. Simultaneously, it reduces the contact area between the fixture and the non-edge areas of the circuit board, increasing the effective area for direct negative pressure application, allowing for more thorough transfer of adsorption force, and further enhancing the flatness of the adsorption surface.

[0020] Preferably, the load-bearing fixture is positioned on the pressure equalizing plate by a positioning pin or a snap-fit ​​structure.

[0021] Positioning and connection via locating pins or snap-fit ​​structures provide a fast, precise, and robust assembly method. Locating pins ensure repeatability and consistency across production batches. Snap-fit ​​structures allow for quick assembly and disassembly without tools, facilitating fixture replacement and maintenance, and adapting to flexible production needs. Both methods prevent fixture movement during the process, ensuring the integrity and sealing of the entire negative pressure transmission path.

[0022] Preferably, the vacuum adsorption stage is adapted to the MPM type printing press.

[0023] Specifically designed for MPM printing presses, its dimensions and interfaces are optimized for this equipment. This targeted design ensures the suction table can be seamlessly integrated into the printing press system as a dedicated module, enabling rapid installation and docking. It provides a direct and effective solution to the deformation challenges encountered when printing ultra-thin circuit boards on this specific equipment, reducing the complexity of equipment modification, improving the maturity of process integration, and allowing users to directly apply this technology to improve print quality and yield.

[0024] The advantages of this utility model compared to the prior art are: This invention relates to a vacuum adsorption stage for ultra-thin circuit boards. Through the cooperation of a base frame, an equalizing plate, and a support fixture, a multi-stage negative pressure transfer system is constructed. The negative pressure channels formed inside the base frame can distribute the negative pressure relatively evenly to the area above it. The equalizing plate further equalizes and diffuses the negative pressure. The support fixture, through its negative pressure holes, ultimately applies the equalized negative pressure to the back of the circuit board. This layered and progressive structural design helps promote the uniform distribution of adsorption force on the circuit board's support surface, providing structural support for suppressing deformation of thin circuit boards. Simultaneously, this modular composition facilitates equipment maintenance and adaptation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a structural diagram of a support fixture according to an embodiment of the present invention.

[0027] Figure 2 This is a top view of the base frame according to an embodiment of the present invention.

[0028] Figure 3 This is a front view of the base frame according to an embodiment of the present invention.

[0029] Figure 4 This is a side view of the base frame according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of the structure of a vacuum adsorption stage for ultra-thin circuit boards according to an embodiment of the present invention.

[0031] Labeling explanation: 1 base frame, 11 transverse component, 12 longitudinal component, 13 first negative pressure hole, 14 electromagnetic locking assembly, 2 equalizing plate, 3 bearing fixture, 31 third negative pressure hole, 32 positioning groove, 33 positioning flange. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of this application, it should be understood that the terms "upper," "lower," "left," "right," "vertical," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0036] The technical solutions in this application will now be described with reference to the accompanying drawings. Example 1

[0037] This embodiment provides a vacuum adsorption stage for ultra-thin circuit boards, including a base frame 1, a pressure equalizing plate 2, and a support fixture 3. The base frame 1 includes a grid structure formed by connecting hollow transverse members 11 and hollow longitudinal members 12. The hollow interiors of these transverse members 11 and longitudinal members 12 are interconnected at the connection nodes, thereby forming a continuous and interconnected negative pressure flow channel network within the entire grid structure. The upper surface of this negative pressure flow channel network is provided with a plurality of first negative pressure holes 13. The pressure equalizing plate 2 is mounted on the base frame 1 and is provided with second negative pressure holes. The support fixture 3 is used to support the circuit board and is positioned on the pressure equalizing plate 2, and is provided with third negative pressure holes 31. A first sealing member is provided between the pressure equalizing plate 2 and the base frame 1. A second sealing member is provided between the support fixture 3 and the pressure equalizing plate 2 and / or between the support fixture 3 and the circuit board. The base frame 1, pressure equalizing plate 2, support fixture 3, first sealing member, and second sealing member are configured to form a sealed negative pressure chamber together with the circuit board.

[0038] This vacuum adsorption stage utilizes a three-layer modular structure design—base frame 1, pressure equalizing plate 2, and support fixture 3—to construct a stable and efficient negative pressure adsorption system. The base frame 1 employs a hollow transverse component 11 and a longitudinal component 12 forming a grid structure. This not only provides robust mechanical support for the entire stage, ensuring structural rigidity to resist external pressure, but more importantly, the negative pressure flow channel formed within it acts as a main distribution channel, guiding the negative pressure relatively evenly to a large area of ​​the stage surface. The pressure equalizing plate 2, as the intermediate layer, plays a crucial role in connecting the upper and lower layers, performing the initial pressure equalization and diffusion of the negative pressure transmitted from the first negative pressure hole 13 of the base frame 1. The uppermost support fixture 3 directly contacts the ultra-thin circuit board, and its third negative pressure hole 31 is responsible for ultimately transferring the negative pressure to the back of the circuit board. This three-stage negative pressure transmission path—from the grid main channel to the intermediate pressure equalizing plate 2, and then to the dense fixture adsorption points—effectively avoids problems such as excessive stretching of localized areas of the circuit board or insufficient adsorption force in certain areas due to uneven or concentrated negative pressure supply. For ultra-thin circuit boards with extremely small thicknesses, even the slightest unevenness in stress can cause deformation. This structure, through a step-by-step pressure equalization method, ensures that the adsorption force can act smoothly and over a large area on the entire back of the circuit board, thereby significantly improving the control over the flatness of the circuit board and laying a solid foundation for subsequent high-precision solder paste printing processes. The entire device has a clear structure, with each component having a well-defined function, working together to achieve efficient and reliable vacuum adsorption and fixation.

[0039] In this embodiment, the number of third negative pressure holes 31 on the support fixture 3 is much greater than the number of first negative pressure holes 13 on the base frame 1.

[0040] This significant difference in quantity constructs a sophisticated system from macroscopic negative pressure distribution to microscopic negative pressure action. The relatively few first negative pressure holes 13 on the base frame 1 serve to deliver negative pressure from the main negative pressure channel to the equalizing plate 2, while the far more numerous third negative pressure holes 31 on the support fixture 3 are responsible for dispersing the collected negative pressure to as many contact points as possible. This design greatly increases the density of negative pressure application points, making the adsorption force applied to the back of the circuit board more continuous and uniform. It effectively eliminates "suspended" or weak support points that may occur in localized areas of the circuit board due to insufficient adsorption points or excessive spacing, thus preventing these areas from experiencing minor warping or vibration during the process due to stress or heat. For circuit boards with large areas or extremely thin thicknesses, this dense layout of negative pressure holes provides a stable support effect similar to surface contact, further enhancing the ability to suppress circuit board deformation and improving the adaptability of the entire adsorption system to circuit boards of different sizes and shapes, as well as the stability of its operating state.

[0041] In this embodiment, the upper surface of the support fixture 3 is provided with a positioning groove 32 for positioning the circuit board. The positioning groove 32 is surrounded by a positioning flange 33, and the shape of the positioning flange 33 is adapted to the shape and size of the circuit board.

[0042] The positioning groove 32 and positioning flange 33 structure on the upper surface of the support fixture 3 provide a fast and accurate mechanical positioning reference for the placement of the circuit board. The shape formed by the positioning flange 33 closely matches the contour of the circuit board, allowing operators or automated equipment to easily and accurately embed the circuit board into the predetermined position, greatly reducing alignment adjustment time and improving production efficiency. This positioning mechanism not only ensures the positional accuracy of the circuit board on the horizontal plane, but more importantly, it plays a key role in the vertical positioning and limiting of ultra-thin circuit boards. The flange structure can limit the lateral slippage or rotation of the circuit board that may occur during the adsorption process or when subjected to slight external disturbances, ensuring that the circuit board is always within the predetermined process area. This combination of physical limiting and vacuum adsorption constitutes a dual constraint on the circuit board in both the horizontal and vertical directions, thereby providing a reliable positional guarantee for achieving high-precision subsequent printing processes and reducing product defects caused by inaccurate positioning.

[0043] During assembly, first place the first sealing component in the sealing groove on the upper surface of the base frame 1, ensuring it is flat and in place. Then, slowly lower the pressure equalizing plate 2, aligning it with the positioning features on the base frame 1, and secure it using fasteners or positioning pins. Care must be taken to avoid displacement or damage to the sealing component during this process. Next, align the support fixture 3 with the corresponding positioning part on the surface of the pressure equalizing plate 2 through its positioning holes or snap-fit ​​structure and install it in place. If a second sealing component is provided between the support fixture 3 and the pressure equalizing plate 2, ensure it is uniformly compressed. Finally, connect the external vacuum tube to the negative pressure interface on the side of the base frame 1 and connect it to the control circuit of the electromagnetic locking assembly 14, thus completing the assembly and preparation of the entire vacuum adsorption stage.

[0044] When the vacuum system is activated, the negative pressure is transmitted through the negative pressure channel of the base frame 1, the second negative pressure hole of the pressure equalizing plate 2, and finally to the third negative pressure hole 31 of the support fixture 3. This step-by-step transmission and pressure equalization process helps to form a uniformly distributed adsorption force on the upper surface of the support fixture 3.

[0045] In this embodiment, the third negative pressure hole 31 is distributed in the inner and outer areas of the positioning groove 32.

[0046] The third negative pressure hole 31 is simultaneously distributed in both the internal and external areas of the positioning groove 32, achieving full-coverage negative pressure effect on the circuit board adsorption area. When the circuit board is embedded in the positioning groove 32, the negative pressure holes located in the internal area of ​​the positioning groove 32 directly act on the back of the circuit board, providing the main adsorption force to overcome deformation. Meanwhile, the negative pressure holes distributed in the external area of ​​the positioning groove 32, near the positioning flange 33, effectively adsorb and constrain the edge areas of the circuit board. The edges of the circuit board, especially those of ultra-thin circuit boards, are most prone to warping when lacking support. This design ensures that the entire supported area from the center to the edge of the circuit board receives sufficient negative pressure support, eliminating any gaps or weak areas in adsorption force. This indiscriminate, full-area adsorption support more effectively balances the internal stress of the circuit board, significantly preventing edge warping and ensuring a tight overall attachment to the surface of the support fixture 3, thus providing a flatter and more stable working plane for demanding printing processes.

[0047] In this embodiment, electromagnetic locking components 14 are respectively provided in the four corner areas of the bottom of the base frame 1, and the bottom surface of the electromagnetic locking components 14 does not extend beyond the bottom surface of the equalizing plate 2.

[0048] Electromagnetic locking components 14, located at the four corners of the base frame 1, provide a quick, stable, and non-invasive installation method. Through electromagnetic force, the entire vacuum adsorption table can be instantly and securely locked onto the matching printing press work platform. This connection method avoids the cumbersome and time-consuming installation problems associated with complex mechanical fasteners, facilitating rapid line changes and maintenance during production. The design of the bottom surface of the electromagnetic locking components 14 not exceeding the bottom surface of the pressure equalizing plate 2 ensures that the bottom of the adsorption table is a complete and interference-free plane when placed on a flat surface, thus guaranteeing placement stability. Simultaneously, this design avoids the risk of scratches or interference to the printing press work platform or other precision components that might be caused by excessively protruding locking components, reflecting the safety and user-friendliness of the integrated equipment. This fixing method provides strong locking force while also considering operational convenience and equipment safety.

[0049] In this embodiment, the base frame 1 is provided with multiple negative pressure interfaces, all of which are connected to the negative pressure flow channel.

[0050] Multiple negative pressure interfaces, connected to the internal negative pressure channels, are installed on the base frame 1, constructing a multi-point negative pressure supply system. Compared to single-point access, the multi-negative pressure interface design allows negative pressure to be supplied to the negative pressure channels simultaneously from different locations. This significantly accelerates the establishment of negative pressure throughout the system, especially in the negative pressure channel network of the large base frame 1, shortening production preparation time. More importantly, it helps maintain the dynamic balance of pressure within the entire negative pressure channel, avoiding insufficient negative pressure at the far end of the channel due to excessive distance or limited flow at a single air inlet point. This balanced negative pressure supply provides a more stable and consistent pressure source for the equalizing plate 2 and the supporting fixture 3, ensuring highly uniform adsorption force acting on the back of the circuit board from the system source. This further consolidates the effectiveness of the vacuum adsorption stage in suppressing deformation of ultra-thin circuit boards and improves the system's performance in large-area adsorption applications.

[0051] In this embodiment, the first sealing component is an O-ring or a silicone gasket. The second sealing component can be antistatic foam, a silicone pad, etc.

[0052] This brings significant synergistic advantages. First, both types of seals are industrial standard parts, inexpensive, easy to procure and replace, greatly improving the maintainability and economy of the equipment. Second, they possess excellent elasticity and compression set, enabling them to form a stable, reliable, and long-life static seal between the equalizing plate and the base frame, effectively preventing negative pressure leakage and providing a fundamental guarantee for the establishment and maintenance of the core negative pressure chamber. Finally, O-rings are suitable for groove sealing, while silicone gaskets are more suitable for planar sealing. This limitation provides a clear and mature implementation path for manufacturing requirements with different precision and cost, ensuring the feasibility and optimization of the sealing solution of this utility model.

[0053] In this embodiment, the supporting fixture 3 is a frame structure with a hollowed-out window.

[0054] The support fixture 3 adopts a frame structure with a perforated window. This design optimizes the fixture's physical properties while achieving its function. The frame structure itself provides reliable peripheral support for the circuit board, ensuring the overall structural strength of the fixture. The perforated window design in the middle significantly reduces the overall weight of the fixture, making it easier to handle and move, which helps improve the efficiency of fixture changes on the production line and reduces the labor intensity of operators. On the other hand, it reduces the contact area between the fixture and the non-edge areas of the circuit board, maximizing the effective area where negative pressure directly acts on the back of the circuit board. This allows the adsorption force to be transmitted more fully and directly, reducing the negative impact on the adsorption effect that may be caused by the fixture body obstructing it, thereby further improving the flatness of the adsorption.

[0055] In this embodiment, the bearing fixture 3 is positioned on the pressure equalizing plate 2 by a positioning pin or a snap-fit ​​structure.

[0056] The support fixture 3 is positioned and connected to the pressure equalizing plate 2 via locating pins or a snap-fit ​​structure, providing a fast, precise, and stable assembly method. The locating pins ensure that the support fixture 3 is consistently positioned accurately each time it is installed, guaranteeing consistency between production batches, which is crucial for high-precision automated production. The snap-fit ​​structure allows for quick assembly and disassembly without tools, greatly facilitating fixture replacement and maintenance, and adapting to the flexible production needs of multiple varieties and small batches. Both methods provide a reliable connection, preventing the support fixture 3 from moving or drifting relative to the pressure equalizing plate 2 during the process. This ensures the integrity and sealing of the negative pressure transmission path formed by the base frame 1, the pressure equalizing plate 2, and the support fixture 3, thereby guaranteeing the stability and reliability of the entire vacuum adsorption table.

[0057] In this embodiment, the vacuum adsorption stage is adapted to an MPM type printing machine.

[0058] The vacuum adsorption stage is specifically adapted for the MPM printing press, meaning its structural dimensions, interface specifications, and operating characteristics are optimized for the process requirements and installation space constraints of this model. This targeted adaptation ensures that the adsorption stage can be seamlessly integrated as a dedicated module into the existing production system of the MPM printing press, enabling rapid installation and integration. It fully leverages the high-performance potential of the MPM printing press, providing a direct and effective solution to the deformation challenges encountered when printing ultra-thin circuit boards on this specific equipment. This specialized design reduces the complexity of equipment modification and debugging, enhances the maturity and reliability of process integration, and allows users to directly apply this technology on the corresponding equipment platform, efficiently improving the printing quality and production yield of ultra-thin circuit boards.

[0059] It should be noted that, in the accompanying drawings of this embodiment ( Figures 1 to 5 In order to clearly illustrate the core improvement of this embodiment—namely, the three-stage negative pressure transmission and support structure consisting of the base frame 1, the equalizing plate 2, and the supporting fixture 3—some components that are conventionally used in vacuum adsorption devices in the field and are not innovative features of this embodiment are not shown in the figures. These components include, but are not limited to: the second negative pressure hole provided on the equalizing plate 2, the negative pressure interface provided on the base frame 1 for connecting to the external vacuum pipeline, and the first sealing member sandwiched between the equalizing plate 2 and the base frame 1 to ensure the airtightness of the chamber.

[0060] All components not shown above are common knowledge or standard elements in this technical field. For example, the second negative pressure holes are usually formed in a uniformly distributed array on the pressure equalizing plate, and their function is to make the negative pressure airflow from the base frame 1 diffuse more evenly in the horizontal and vertical directions; the negative pressure interface is a standard pneumatic quick-connect or threaded interface, and its number and position can be conventionally selected according to the actual adsorption area and the required negative pressure build-up speed; the first sealing component is usually an O-ring, a rectangular sealing strip, or a molded silicone pad, etc. When implementing this embodiment, those skilled in the art can select and adapt the specific models, materials, and installation methods of these components from the prior art without creative effort, based on the actual working conditions, sealing requirements, and vacuum system specifications. This omission of drawings does not affect the understanding of the innovative structure of this embodiment and makes the core inventive points more prominent. Example 2

[0061] 1. Overall Structure and Assembly Steps Reference Figures 1 to 5 The assembly process of the vacuum adsorption stage for ultra-thin circuit boards in this embodiment is as follows: Step 1: Prepare the base frame 1 The base frame 1 is made of 6061 aluminum alloy, CNC machined and welded. It consists of hollow transverse members 11 and hollow longitudinal members 12 orthogonally connected to form a 4x4 grid structure. The inner cavities of all transverse members 11 and longitudinal members 12 are welded together at their intersections to ensure connectivity, thus forming a continuous, sealed negative pressure flow channel network within the entire frame. One or both ends of this flow channel network are equipped with a standard G1 / 4-inch negative pressure interface (not shown in the figure) for connecting an external vacuum generator. At the center of each grid cell on the upper surface of the frame, a first negative pressure hole 13 with a diameter of 2mm is machined. At the four bottom corners of the base frame 1, electromagnetic locking assemblies 14 are fixedly installed with screws. Their bottom surfaces are precision ground to ensure coplanarity with the bottom surface of the equalizing plate 2, preventing interference.

[0062] Step 2: Install the pressure equalizing plate 2 and the seal. The equalizing plate 2 is a single piece of 10mm thick aluminum alloy plate, and its flatness has been ground to ensure it is less than 0.05mm / m. On the lower surface of the equalizing plate 2, corresponding to the grid area of ​​the base frame 1, a large number of second negative pressure holes with a diameter of 1mm are uniformly machined at 20mm intervals (not shown in the figure). Before installation, a closed silicone sealing strip with a rectangular cross-section is first laid in the sealing groove on the upper surface of the base frame 1 as the first sealing component (not shown in the figure). Then, the equalizing plate 2 is aligned with the positioning pin on the base frame 1, smoothly lowered, and tightened with the M6 ​​socket head cap screws around it. The first sealing component is uniformly compressed, ensuring the airtightness at the interface between the two.

[0063] Step 3: Place the support fixture 3 The support fixture 3 is made of aluminum alloy using CNC precision machining. It is a frame structure with a large central hollow window to reduce weight. A positioning groove 32 with a depth of 0.5mm is engraved on its upper surface. This positioning groove 32 is surrounded by a positioning flange 33, and its shape perfectly matches the 0.3mm thick ultra-thin circuit board to be processed. On the entire surface of the support fixture 3, third negative pressure holes 31 with a diameter of 0.8mm are densely distributed at 5mm intervals, covering both the interior and exterior areas of the positioning groove 32. The support fixture 3 uses two positioning holes to engage with corresponding positioning pins on the pressure equalizing plate 2, achieving rapid and precise positioning. A thin layer of anti-static foam (which can serve as a second sealing component) is attached to the contact surface between the support fixture 3 and the pressure equalizing plate 2 to assist in sealing and buffer pressure.

[0064] 2. Working process and performance data The assembled vacuum adsorption stage is fixed to the working platform of the MPM printing machine using the electromagnetic locking assembly 14. The ultra-thin circuit board is placed into the positioning slot 32 of the support fixture 3, ensuring its accurate positioning.

[0065] The vacuum generator is activated, and negative pressure passes through the system sequentially: The negative pressure passes through the following channels in sequence: negative pressure interface of base frame 1 → internal mesh negative pressure channel → first negative pressure hole 13 → second negative pressure hole of equalizing plate 2 → third negative pressure hole 31 of bearing fixture 3 → final negative pressure chamber formed by the back of circuit board and the upper surface of bearing fixture 3.

[0066] In this multi-stage transmission and equalization process, the negative pressure is effectively homogenized. Tests showed that when the external vacuum source reaches -80 kPa, the pressure non-uniformity of the negative pressure field acting on the back of the circuit board can be controlled within ±2%. For a 300mm x 300mm circuit board, the system takes less than 3 seconds to establish a stable negative pressure from startup.

[0067] 3. Selection and Effects of Key Components Material selection: The base frame 1, the pressure equalizing plate 2, and the load-bearing fixture 3 are all made of aluminum alloy. While ensuring overall rigidity, lightweight and flatness stability, the types of materials are simplified, the structural consistency is improved, and recycling is facilitated.

[0068] Negative pressure orifice design: The number and size of the three-stage negative pressure orifices decrease (first negative pressure orifice: few and large to ensure flow rate; third negative pressure orifice: many and small to ensure uniform distribution), forming a highly efficient system of "macroscopic distribution → intermediate pressure equalization → microscopic adsorption".

[0069] Sealing design: Multi-layer sealing (the first sealing component, the second sealing component, and the positioning flange itself also play a certain sealing role) ensures the airtightness of the entire negative pressure path and minimizes pressure loss.

[0070] In summary, this embodiment effectively solves the deformation problem of ultra-thin circuit boards during the printing process through the specific structural design, material selection, and process coordination described above. Actual measurements show that using this adsorption stage, the overall deformation of the circuit board during printing can be controlled below 0.1mm. Compared to traditional support methods, the thickness uniformity (CPK) of solder paste printing is improved by more than 30%, significantly enhancing the first-pass yield and reliability of the product.

[0071] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vacuum adsorption stage for ultra-thin circuit boards, characterized in that, The system includes a base frame (1), a pressure equalizing plate (2), and a support fixture (3). The base frame (1) includes a grid structure formed by connecting hollow transverse members (11) and hollow longitudinal members (12). The grid structure forms a negative pressure flow channel inside and has multiple first negative pressure holes (13) on its upper surface. The pressure equalizing plate (2) is mounted on the base frame (1) and has second negative pressure holes. The support fixture (3) is used to support the circuit board and is positioned on the pressure equalizing plate (2). It has third negative pressure holes (31). A first sealing member is provided between the pressure equalizing plate (2) and the base frame (1). A second sealing member is provided between the support fixture (3) and the pressure equalizing plate (2) and / or between the support fixture (3) and the circuit board. The base frame (1), pressure equalizing plate (2), support fixture (3), first sealing member, and second sealing member are configured to form a sealed negative pressure chamber together with the circuit board.

2. The vacuum adsorption stage according to claim 1, characterized in that, The number of third negative pressure holes (31) on the bearing fixture (3) is much greater than the number of first negative pressure holes (13) on the base frame (1).

3. The vacuum adsorption stage according to claim 1, characterized in that, The upper surface of the support fixture (3) is provided with a positioning groove (32) for positioning the circuit board. The positioning groove (32) is surrounded by a positioning flange (33). The shape of the positioning flange (33) is adapted to the shape and size of the circuit board.

4. The vacuum adsorption stage according to claim 3, characterized in that, The third negative pressure hole (31) is distributed in the internal and external areas of the positioning groove (32).

5. The vacuum adsorption stage according to claim 1, characterized in that, Electromagnetic locking components (14) are respectively provided in the four corner areas of the bottom of the base frame (1), and the bottom surface of the electromagnetic locking components (14) does not exceed the bottom surface of the equalizing plate (2).

6. The vacuum adsorption stage according to claim 1, characterized in that, The base frame (1) is provided with multiple negative pressure interfaces, all of which are connected to the negative pressure flow channel.

7. The vacuum adsorption stage according to claim 1, characterized in that, The first sealing component is an O-ring or a silicone gasket.

8. The vacuum adsorption stage according to claim 1, characterized in that, The supporting fixture (3) is a frame structure with a hollowed-out window.

9. The vacuum adsorption stage according to claim 1, characterized in that, The bearing fixture (3) is positioned on the pressure equalizing plate (2) by a positioning pin or a snap-fit ​​structure.

10. The vacuum adsorption stage according to claim 1, characterized in that, The vacuum adsorption stage is compatible with MPM type printing machines.

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