SMT active steel mesh suitable for automobile electronics and monitoring and adjusting method

Abstract

The application relates to an SMT movable steel mesh suitable for automobile electronics and a monitoring and adjusting method. The movable steel mesh comprises side sealing plates, which are connected in a head-to-tail mode through right-angle joints arranged between the side sealing plates, steel sheet fixing components F, which are respectively arranged on the inner sides of the side sealing plates and are used for mounting cooperation with the steel sheets, integrated sensing modules, which are arranged on one side of the steel sheet fixing components and are used for acquiring the workpiece surface profile of a pcb to be printed, piezoelectric ceramics, one end of which is arranged on the inner side of the side sealing plate and the other end of which penetrates through the side sealing plate and is dynamically connected with the steel sheet, and a control module, which is electrically connected with the integrated sensing modules and the piezoelectric ceramics and is used for generating corresponding gap adaptive decisions according to the workpiece surface profile, the gap adaptive decisions being used for controlling the piezoelectric ceramics to abut against the steel sheet downward, so that a stable adhering state can be maintained when there is local warping or uneven surface of the PCB, the uniformity of solder paste deposition is improved, and the occurrence probability of welding defects such as false welding and bridging is reduced.

Description

Technical Field

[0001] This invention relates to the technical field of movable stencils, and in particular to an SMT movable stencil suitable for automotive electronics and a monitoring and adjustment method thereof. Background Technology

[0002] Currently, in the field of electronic manufacturing, surface mount technology (SMT) is widely used in the production process of electronic products. Among them, stencil printing is used to accurately transfer solder paste to the pad area of ​​the printed circuit board (PCB), which is an important step in ensuring soldering quality.

[0003] In existing technologies, stencils typically employ a one-piece structural design, made entirely of metal, and maintained flatness through a fixed tensioning method. While the manufacturing process for this type of structure is mature, the overall manufacturing cost is high, and its flatness adjustment capability is limited, making it difficult to adapt to different PCB shapes. As automotive electronics products evolve towards miniaturization, high integration, and complex structures, PCB substrates in components such as in-vehicle displays and control modules are prone to localized bending or curved surfaces. During the stencil printing process, traditional fixed stencils struggle to achieve full adhesion to the PCB surface, easily leading to uneven solder paste deposition, which in turn causes quality issues such as cold solder joints and short circuits, affecting product reliability and production yield. Although some existing stencil structures attempt to improve adaptability through localized adjustments, their overall adjustment capability remains limited, making it difficult to achieve dynamic adhesion control between the stencil and the PCB. Summary of the Invention

[0004] To address the issue of poor adhesion between the stencil and the PCB, which leads to reduced product reliability and production yield, this application provides an SMT movable stencil suitable for automotive electronics and a monitoring and adjustment method thereon.

[0005] A movable stencil for automotive electronics, comprising: There are four side panels in total, and each pair of them is connected end to end by a right-angle joint to form a corresponding rectangular frame. Steel sheet fixing components F are located on the inner side of each of the side sealing plates for mounting and engaging with the steel sheet; An integrated sensing module, located on one side of the steel sheet fixing component, is used to acquire the workpiece surface contour of the PCB to be printed. The piezoelectric ceramic has one end located inside the side sealing plate and the other end passing through the side sealing plate and dynamically connected to the steel sheet. The control module is electrically connected to the integrated sensing module and the piezoelectric ceramic, respectively, and is used to generate corresponding gap adaptive decisions based on the surface contour of the workpiece. The gap adaptive decisions are used to control the piezoelectric ceramic to push downward against the steel sheet so that the steel sheet and the PCB to be printed adaptively fit together.

[0006] By adopting the above technical solution, a stable rectangular frame is formed by four side sealing plates and right-angle joints. Steel sheet fixing components, integrated sensing modules, piezoelectric ceramics, and control modules are set in the frame. This enables the steel mesh structure to have real-time sensing and dynamic adjustment capabilities for the surface condition of the PCB to be printed. It can actively compensate for the bonding error between the steel sheet and the PCB during the printing process, thereby improving the uniformity of solder paste deposition and the reliability of welding, and reducing the probability of printing defects caused by PCB curvature or assembly tolerances.

[0007] Preferably, the side sealing plate is provided with a fixing strip, which is perpendicularly connected to the piezoelectric ceramic. The side sealing plate is provided with a detection through hole. The side of the fixing strip away from the side sealing plate is a slope, which is connected to the integrated sensing module so that the detection end of the integrated sensing module is correspondingly set with the detection through hole.

[0008] By adopting the above technical solution, by setting a fixing strip inside the side sealing plate and using the inclined structure of the fixing strip to guide the spatial attitude of the integrated sensing module, the detection end and the detection through hole can form a stable alignment relationship, which can improve the accuracy and stability of the sensor detection path, and at the same time enhance the installation reliability of the sensing module in the vibration environment of equipment operation, thereby improving the accuracy of workpiece surface contour acquisition.

[0009] Preferably, the integrated sensing module includes at least one EMOS laser displacement sensor.

[0010] By adopting the above technical solution, and using at least one EMOS laser displacement sensor to perform non-contact detection on the surface of the PCB to be printed, high-resolution measurement of minute height changes can be achieved, reducing the mechanical disturbance to the steel sheet and PCB surface caused by traditional contact measurement, and improving the real-time performance and accuracy of surface contour acquisition of complex curved workpieces, thereby enhancing the response capability of subsequent adjustment and control.

[0011] Preferably, the steel sheet fixing component includes a movable part and a tensioning drive assembly. The driving end of the tensioning drive assembly abuts against one end of the movable part to cause the movable part to rotate and deform, thereby causing the other end of the movable part to fasten the steel sheet. The other end of the movable part is provided with a chamfer that is turned outward towards the outside of the rectangular frame.

[0012] By adopting the above technical solution, and by setting the movable part and the tensioning drive assembly to form a linkage clamping structure, the steel sheet can maintain a uniform tension during assembly and operation. Furthermore, the chamfering structure of the movable part reduces the local stress concentration phenomenon during the clamping process of the steel sheet, thereby improving the flatness stability of the steel sheet and extending its service life.

[0013] Preferably, the tensioning drive assembly includes a piston seat, a piston, and an elastic element. The piston seat is located on one side of the movable element. The piston seat has a cavity and an inlet / outlet air pipe communicating with the cavity. The piston is located in the cavity and is sleeved with the elastic element so that one end of the piston abuts against the movable element to serve as the drive end of the tensioning drive assembly, and the other end of the piston abuts against the piston seat.

[0014] By adopting the above technical solution, a pneumatic tensioning drive structure is formed by the piston seat, piston, and elastic element, which enables the steel sheet tensioning process to have adjustable buffering characteristics. This can absorb external vibration and impact while ensuring stable output of clamping force, thereby improving the dynamic stability and repeatability of the steel sheet clamping structure and enhancing the reliability of the overall steel mesh structure.

[0015] A monitoring and adjustment method for SMT movable stencils suitable for automotive electronics is provided, the method comprising: Based on the integrated sensing module, the workpiece surface contour and test auxiliary information are acquired. The test auxiliary information includes at least spatial position information, fitting reference information and measurement status information. Based on the workpiece surface contour and the spatial position information, a corresponding workpiece surface height distribution feature is generated; Based on the workpiece surface contour and the bonding reference information, corresponding bonding gap evaluation parameters are generated; Based on the workpiece surface contour and the measurement state information, a corresponding measurement reliability feature is generated; Based on the workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics, a corresponding gap adaptive decision is generated.

[0016] By adopting the above technical solution, and by simultaneously acquiring the workpiece surface contour and test auxiliary information including spatial position information, bonding reference information and measurement status information, the system can comprehensively analyze the bonding status of the steel sheet and PCB from three dimensions: geometric structural features, bonding status deviation, and the reliability of measurement data, thereby improving the accuracy and stability of gap adjustment decisions.

[0017] Preferably, the step of generating corresponding workpiece surface height distribution features based on the workpiece surface contour and the spatial position information includes: The position of each contour sampling value in the acquired workpiece surface contour is calibrated so that the contour sampling value is spatially associated with the corresponding spatial position information, wherein each contour sampling value corresponds to a pre-divided spatial region. Based on the spatial relationship, the height values ​​of the workpiece surface contour in different spatial regions are arranged and mapped to generate a corresponding height distribution description. Based on the height distribution description, the height variation relationship between adjacent spatial regions is extracted to generate the corresponding workpiece surface height distribution features.

[0018] By adopting the above technical solution, a spatial correlation is established between the sampled values ​​of the workpiece surface contour and the spatial position information, and the height change characteristics between different spatial regions are extracted. This enables the system to accurately identify the bending trend and local deformation distribution of the PCB surface, thereby providing a precise spatial geometric reference for steel sheet bonding adjustment.

[0019] Preferably, the step of generating corresponding bonding gap evaluation parameters based on the workpiece surface contour and the bonding reference information includes: The fitting reference information is subjected to reference alignment processing so that the fitting reference information and each height feature parameter in the height distribution description are in the same fitting reference system, thereby establishing a corresponding reference correspondence. Based on the aforementioned benchmark correspondence, each height feature parameter in the height distribution description is compared with the corresponding fitting standard to generate a relative fitting gap description for each spatial region. Based on the description of the relative fitting gap, the fitting gap status of each spatial region is summarized and characterized to generate corresponding fitting gap evaluation parameters.

[0020] By adopting the above technical solution, the system can quantify the bonding deviation distribution between the steel sheet and the PCB by aligning the height distribution characteristics with the bonding reference information under a unified reference system and calculating the relative bonding gap state of each spatial region, thereby providing a clear error assessment basis for dynamic pressure adjustment.

[0021] Preferably, generating corresponding measurement reliability features based on the workpiece surface contour and the measurement state information includes: The measurement status information is processed for status recognition to determine the effective measurement status of each contour sampling value of the workpiece surface contour. Based on the preset measurement status threshold, the effective measurement status is compared and a corresponding abnormal status identifier is generated in the corresponding spatial region. Based on the abnormal state identifier, a corresponding processing strategy is determined. The processing strategy includes removing, correcting, or compensating the contour sample values ​​to generate a corresponding valid contour data set. The continuous stability of the effective contour data set is assessed to generate corresponding measurement confidence features.

[0022] By adopting the above technical solution, the effective identification of measurement status information and the elimination, correction or compensation of abnormal sampling data are carried out, so that the contour data involved in the adjustment calculation can maintain continuous stability, thereby reducing the interference of measurement noise or sensor abnormalities on the adjustment control results and improving the robustness of the overall control system.

[0023] Preferably, the step of generating the corresponding gap adaptive decision based on the workpiece surface height distribution characteristics, the fitting gap evaluation characteristics, and the measurement reliability characteristics includes: The workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics are weighted and fused according to preset weighting coefficients to generate corresponding fused data; The property data of the piezoelectric ceramic is obtained, and the corresponding constraints are mapped according to the property data. Based on the constraints and the fused data, the corresponding gap adaptive decision is generated.

[0024] By adopting the above technical solution, the workpiece surface height distribution characteristics, bonding gap evaluation characteristics and measurement reliability characteristics are weighted and fused, and constrained and matched with the piezoelectric ceramic actuation characteristics. This enables the gap adjustment decision to accurately reflect the actual bonding requirements of the workpiece and conform to the physical action boundary of the actuator, thereby improving the stability and response accuracy of the steel sheet adaptive bonding control.

[0025] In summary, this application includes at least one of the following beneficial technical effects: This application addresses the problem of stencils being unable to adhere to complex curved surfaces by constructing a dynamic adaptive structural system capable of sensing the actual shape of the PCB and actively adjusting the bonding state. By setting steel sheet fixing components inside a rectangular frame, the steel sheet maintains tension while possessing a certain stress response capability, providing load-bearing conditions for subsequent deformation adjustment from a structural foundation. Simultaneously, an integrated sensing module is arranged on one side of the steel sheet to acquire the actual surface contour of the PCB to be printed, enabling the stencil system to obtain real workpiece shape data, thereby changing the traditional stencil printing method that relies on the assumption of a fixed plane. After obtaining the surface contour data, the control module processes and analyzes the relevant information and outputs control commands for adjusting the bonding state. Then, a controllable displacement is applied to the steel sheet through piezoelectric ceramics arranged at the side sealing plate, causing the steel sheet to produce minute deformations in local areas, thereby dynamically changing the gap between the steel sheet and the PCB, ultimately achieving adaptive bonding between the steel sheet and the PCB surface. This transforms the traditional passive, fixed stencil structure into an active, adjustable structure that responds in real-time to changes in workpiece shape. Even with localized warping or surface unevenness on the PCB, it maintains a stable fit, improving solder paste uniformity and reducing the probability of soldering defects such as cold solder joints and bridging. Furthermore, by achieving fit control at the stencil adjustment level, there's no need to increase the overall stencil material grade or precision requirements. This reduces manufacturing and maintenance costs while maintaining printing accuracy, and enhances the stencil's applicability and stability in various PCB production scenarios, ultimately improving the overall assembly quality and production efficiency of automotive electronics products. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the specific structure of an SMT movable stencil suitable for automotive electronics in one embodiment of this application.

[0027] Figure 2 This is a partial structural schematic diagram of an SMT movable stencil suitable for automotive electronics according to one embodiment of this application; Figure 3 This is a top view of a cross-section of an SMT movable stencil suitable for automotive electronics, according to one embodiment of this application; Figure 4 This is a flowchart of a monitoring and adjustment method for an SMT active stencil applicable to automotive electronics, according to one embodiment of this application.

[0028] Explanation of reference numerals in the attached figures: 1. Side sealing plate; 11. Detection through hole; 2. Right angle connector; 3. Steel sheet fixing component; 31. Moving part; 32. Tensioning drive assembly; 321. Piston seat; 322. Piston; 323. Elastic component; 4. Integrated sensing module; 5. Piezoelectric ceramic; 6. Fixing strip. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the accompanying drawings.

[0030] In one embodiment, such as Figure 1 As shown, this application discloses an SMT movable stencil suitable for automotive electronics. The SMT movable stencil for automotive electronics includes: There are four side sealing panels 1, and each pair of them is connected end to end by a right-angle connector 2 to form a corresponding rectangular frame. The steel sheet fixing component 3 is located on the inner side of each side sealing plate 1 for installation and mating with the steel sheet; The integrated sensing module 4 is located on one side of the steel sheet fixing component 3 and is used to obtain the workpiece surface contour of the PCB to be printed. The piezoelectric ceramic 5 has one end located inside the side sealing plate 1, and the other end passes through the side sealing plate 1 and is dynamically connected to the steel sheet; The control module is electrically connected to the integrated sensing module 4 and the piezoelectric ceramic 5 respectively. It is used to generate corresponding gap adaptive decisions based on the surface contour of the workpiece. The gap adaptive decisions are used to control the piezoelectric ceramic 5 to push down against the steel sheet so that the steel sheet and the PCB to be printed can be adaptively bonded and matched.

[0031] In this embodiment, a stencil assembly for SMT printing adopts a split composite structure design. Its overall structure consists of a base frame support structure, a functional printed layer, and a bonding and adjustment structure. The base frame support structure uses high-strength metal to form a rigid outer load-bearing frame, providing overall structural stability for the stencil assembly and withstanding tensile loads during printing. The functional printed layer is made of high-precision thin sheet material to form a printing opening array. This functional printed layer is fixedly installed inside the base frame support structure to achieve precise transfer of solder paste or conductive materials. During structural assembly, the functional printed layer and the base frame support structure are positioned and fixed via an adjustable connection component. This adjustable connection component includes a fine-tuning clamping mechanism and an elastic buffer unit. By applying a controllable preload to the connection points, the functional printed layer can generate a small deformation under stress, thereby compensating for local planar errors within the printing area.

[0032] In practical operation, when the stencil assembly is installed on the printing equipment and aligned with the PCB surface, the adjustment amount of the fine-tuning clamping mechanism can apply differentiated stress distribution to local areas of the functional printed layer. This allows the printed layer to undergo adaptive deformation in a direction perpendicular to the PCB surface, thereby achieving high-precision bonding between the stencil printing surface and the PCB solder pad area. Simultaneously, the elastic buffer unit absorbs printing pressure fluctuations during squeegee movement, maintaining stable contact between the stencil and the PCB and preventing uneven solder paste transfer due to local warping or assembly errors. Through this structural approach, while ensuring the overall structural strength and service life of the stencil, high-precision materials are applied only to the functional printed area, while the outer support structure is manufactured using lower-cost but higher-strength materials, significantly reducing the overall manufacturing cost of the stencil.

[0033] Furthermore, during the printing process, when the squeegee applies linear extrusion force to the stencil surface, pushing the solder paste through the printing opening, the functional printed layer, constrained by the adjustable connection components, can form a uniform surface contact state. This allows the solder paste to form a stable filling pressure field within the opening, reducing solder paste residue and bridging, and improving the consistency of solder joint formation. This structure not only adapts to the needs of planar PCB printing but also enables the printed layer to dynamically adhere to PCB surfaces with slightly curved features by adjusting the preload parameters, thereby meeting the high-reliability soldering requirements of complex circuit boards in automotive electronics products.

[0034] Through the above-mentioned technical means, this embodiment utilizes the synergistic effect of split material configuration and adjustable bonding structure to reduce material costs while ensuring structural strength of the stencil assembly. Furthermore, it significantly improves the bonding accuracy between the stencil and the PCB through a controllable deformation compensation mechanism, effectively improves the uniformity of solder paste deposition, and reduces the risks of cold solder joints, bridging, and solder joint misalignment, thereby improving the stability of the SMT production process and product yield.

[0035] Furthermore, such as Figure 2 As shown, a fixing strip 6 is provided inside the side sealing plate 1. The fixing strip 6 is vertically connected to the piezoelectric ceramic 5. A detection through hole 11 is provided on the side sealing plate 1. The side of the fixing strip 6 away from the side sealing plate 1 is a slope. The slope is connected to the integrated sensing module 4 so that the detection end of the integrated sensing module 4 is set to correspond with the detection through hole 11.

[0036] In this embodiment, the side sealing plate 1 serves as the lateral sealing and mounting base of the overall structure, and a fixing strip 6 is provided inside to construct the mounting support path for the internal structural components. The side sealing plate 1 is preferably made of metal or composite material with high structural strength and sealing performance. In the assembled state, it not only seals the internal functional cavity but also provides a reliable mounting positioning reference for the internal functional devices. The fixing strip 6 is located on the inner side of the side sealing plate 1 and forms a stable connection with it. The fixing strip 6 extends along the inner wall of the side sealing plate 1, and its main function is to provide rigid support and a force transmission channel for the piezoelectric ceramic 5. The fixing strip 6 and the piezoelectric ceramic 5 are connected vertically, so that the polarization direction or deformation direction of the piezoelectric ceramic 5 is spatially orthogonal to the force direction of the fixing strip 6. This structure can effectively convert the deformation of the piezoelectric ceramic 5 into mechanical displacement or stress change along the length of the fixing strip 6 when deformation occurs, thereby ensuring the stability of signal conversion and reducing the impact of lateral interference stress on the working performance of the piezoelectric ceramic 5.

[0037] In terms of structural layout, a detection through-hole 11 is provided through the side sealing plate 1. The detection through-hole 11 is used to construct a signal transmission window between the external detection environment and the internal sensing structure. Its aperture size and position are precisely designed according to the detection target area to ensure the alignment accuracy of the detection path. The end of the fixing strip 6 away from the side sealing plate 1 is machined into a bevel structure. This bevel serves as an installation transition surface and forms a close connection with the integrated sensing module 4. By designing the end of the fixing strip 6 as a bevel, the spatial angle of the integrated sensing module 4 can be guided and positioned during assembly. This allows the integrated sensing module 4 to automatically form a predetermined tilt angle during fixed installation, thereby ensuring that the detection end of the integrated sensing module 4 is accurately aligned with the position of the detection through-hole 11 along the detection direction. This bevel structure can also form a surface contact support state during assembly and clamping. Compared with a single-point or line contact structure, this can improve the installation stability of the integrated sensing module 4 and reduce the adverse effects of local stress concentration on the accuracy of the sensing element.

[0038] Furthermore, during the overall operation, when the piezoelectric ceramic 5 is subjected to external vibration, pressure, or acoustic signals, it will generate corresponding electrical or mechanical deformation signals. These signals form a stable transmission path through the fixing strip 6 and act on the integrated sensing module 4. Since the fixing strip 6 and the integrated sensing module 4 are connected by a beveled fit, the integrated sensing module 4 can achieve fine-tuning of the detection angle while maintaining structural stability. This ensures that the detection end of the integrated sensing module 4 is always coaxial with or aligned with the target via the detection through-hole 11, allowing external signals to be efficiently transmitted to the internal detection unit of the integrated sensing module 4 through the detection through-hole 11. The side sealing plate 1 not only serves a sealing and protection function in this structure but also prevents external impurities or electromagnetic interference from entering the detection cavity, ensuring the stability of the detection environment and the reliability of the detection data.

[0039] In another embodiment, an elastic buffer connection structure is adopted between the fixing strip 6 and the piezoelectric ceramic 5. Specifically, an elastic transition layer is provided between the fixing strip 6 and the piezoelectric ceramic 5. This elastic transition layer can be made of silicone gasket, polyurethane elastic layer or microporous rubber material, and is used to absorb high-frequency vibration or impact loads generated during device operation. In this structure, the side sealing plate 1 still serves as the installation reference and sealing shell of the overall structure. The fixing strip 6 forms a flexible connection with the piezoelectric ceramic 5 through the elastic transition layer, so that the piezoelectric ceramic 5 can generate a small displacement within a controlled range when subjected to external excitation, thereby avoiding stress concentration problems caused by rigid connection. At the same time, the inclined surface at the far end of the fixing strip 6 is still in contact with the integrated sensing module 4, and the alignment relationship between the detection direction of the integrated sensing module 4 and the detection through hole 11 is maintained by the inclined surface guide structure. This embodiment can significantly improve the fatigue resistance and long-term stability of the piezoelectric ceramic 5 while ensuring detection accuracy, and is especially suitable for automotive electronic working environments with continuous vibration or periodic impact.

[0040] In another embodiment, the fixing strip 6 adopts an adjustable installation structure. Specifically, the fixing strip 6 is connected to the side sealing plate 1 via a slide rail structure or a threaded adjustment structure, allowing the fixing strip 6 to be slightly adjusted in position along a preset guide direction inside the side sealing plate 1. During assembly, the spatial distance and tilt angle matching relationship between the piezoelectric ceramic 5 and the integrated sensing module 4 can be changed by adjusting the installation position of the fixing strip 6, so that the detection end of the integrated sensing module 4 can be more accurately aligned with the detection area corresponding to the detection through hole 11. At the same time, the bevel at the end of the fixing strip 6 can automatically change the contact angle with the integrated sensing module 4 according to the adjustment position, so that the integrated sensing module 4 can maintain a stable fit in different installation states. This structure can compensate for the impact of manufacturing tolerances and assembly errors on detection accuracy, and allows for optimization and adjustment of the force path and signal transmission path of the piezoelectric ceramic 5 according to different detection requirements, thereby improving the flexibility and calibration capability of the device to adapt to different working environments.

[0041] Furthermore, the integrated sensing module 4 includes at least one EMOS laser displacement sensor.

[0042] In this embodiment, at least one EMOS laser displacement sensor is integrated inside the integrated sensing module 4. This EMOS laser displacement sensor employs a non-contact measurement principle. Its emitting end projects a laser beam onto the surface of the PCB to be printed, and its receiving end receives the laser signal reflected back from the PCB surface. Based on the phase difference, time difference, or spot displacement change between the emitted and received signals, it outputs a corresponding displacement measurement signal. The EMOS laser displacement sensor is fixedly installed inside the integrated sensing module 4. Its installation posture is guided and limited by the inclined structure at the distal end of the fixing strip 6, ensuring that the laser emission direction forms a predetermined angle with respect to the steel plate plane and the PCB surface. This guarantees that the laser measurement area is located within the effective detection window corresponding to the detection via 11. In the assembled state, the integrated sensing module 4 and the fixing strip 6 form a stable and close connection, allowing the EMOS laser displacement sensor to maintain a fixed spatial position during equipment operation, preventing the detection optical path from shifting due to vibration or temperature changes.

[0043] In actual operation, when the stencil assembly is aligned and ready for printing, the EMOS laser displacement sensor scans and measures the PCB surface in real time, acquiring distance or height information at multiple detection points and converting the measurement signals into electrical signals for output to the control module. Because it uses laser displacement measurement, the EMOS laser displacement sensor can perform high-resolution detection without contacting the PCB surface, thus avoiding mechanical interference to the stencil or PCB surface. Simultaneously, the sensor has high sensitivity to minute height changes, effectively identifying local warping, step changes, or assembly errors on the PCB surface, providing reliable raw detection data for subsequent stencil bonding and adjustment. In this embodiment, by integrating the EMOS laser displacement sensor into the sensing module and forming a fixed and controlled installation relationship with the stencil structure, the detection results have good repeatability and stability, thereby improving the response accuracy and control reliability of the stencil bonding and adjustment process.

[0044] Furthermore, such as Figures 2-3 As shown, the steel sheet fixing component 3 includes a movable part 31 and a tensioning drive assembly 32. The drive end of the tensioning drive assembly 32 abuts against one end of the movable part 31 to cause the movable part 31 to rotate and deform, thereby causing the other end of the movable part 31 to fasten the steel sheet. The other end of the movable part 31 is provided with a chamfer that is turned outward towards the outside of the rectangular frame.

[0045] In this embodiment, the steel sheet fixing component 3 adopts a structure capable of force conversion and self-locking clamping. It includes a movable component 31 and a tensioning drive assembly 32, which work together to complete the tensioning and fixing of the steel sheet. The movable component 31 is preferably a component with a certain degree of elasticity and rotational freedom. One end of it is installed inside the rectangular frame via a rotating shaft or elastic connection, so that the movable component 31 can undergo controlled rotational deformation around its installation position under stress. The tensioning drive assembly 32 is disposed on one side of the movable component 31, and its driving end forms a back-fitting relationship with one end of the movable component 31. When the tensioning drive assembly 32 outputs driving force, the driving force acts on the movable component 31 in a predetermined direction, causing the movable component 31 to rotate around its installation end.

[0046] During operation, when the tensioning drive assembly 32 is under force, its drive end continuously applies a pushing or clamping force to one end of the movable part 31. This force is converted into a rotational torque around the axis of rotation through the structural form of the movable part 31, thereby driving the movable part 31 to rotate and deform. As the movable part 31 rotates, its other end gradually approaches the steel sheet and forms a clamping action, pressing and fixing the steel sheet inside the rectangular frame. Because the rotational deformation of the movable part 31 has a certain elastic stroke, this structure can provide necessary stress buffer space for the steel sheet while ensuring its firm fixation, avoiding local stress concentration or uncontrolled deformation of the steel sheet caused by rigid clamping.

[0047] Furthermore, the end of the movable component 31 furthest from the tensioning drive assembly 32 is provided with a chamfered structure that flares outward from the rectangular frame. This chamfer serves as a guide and transition during the clamping process of the steel sheet, enabling the movable component 31 to form a smooth contact surface when in contact with the steel sheet, reducing the risk of sharp corners cutting or damaging the edges of the steel sheet. Simultaneously, the chamfered structure forms a wrapping clamping state after the movable component 31 completes its rotation, making the steel sheet less prone to slippage or detachment under the pressure of the printing squeegee or vibration loads, thereby improving the stability and reliability of the steel sheet installation.

[0048] Furthermore, such as Figures 2-3 As shown, the tension drive assembly 32 includes a piston seat 321, a piston 322, and an elastic member 323. The piston seat 321 is located on one side of the movable member 31. The piston seat 321 has a cavity and an inlet / outlet air pipe communicating with the cavity. The piston 322 is located in the cavity and is fitted with the elastic member 323 so that one end of the piston 322 abuts against the movable member 31 to serve as the drive end of the tension drive assembly 32, and the other end of the piston 322 abuts against the piston seat 321.

[0049] In this embodiment, the tension drive assembly 32 adopts a structure combining pneumatic drive and elastic reset. It includes a piston seat 321, a piston 322, and an elastic element 323, which together constitute an actuator for outputting a stable tension force. The piston seat 321 is fixedly disposed on one side of the movable element 31 and serves as the external support housing of the tension drive assembly 32. Its interior forms a closed cavity to provide axial movement space for the piston 322. The piston seat 321 is provided with an inlet and outlet air pipe that communicates with the cavity. This inlet and outlet air pipe is used to connect to an external air source or air circuit control unit to regulate the air pressure inside the cavity, thereby controlling the stroke and output force of the piston 322 within the cavity.

[0050] The piston 322 is disposed inside the cavity of the piston seat 321, and its external dimensions match the inner wall of the cavity, allowing the piston 322 to slide stably in the axial direction within the cavity. The piston 322 is fitted with an elastic element 323, which is preferably a spring structure, with one end abutting against the piston 322 and the other end abutting against the inner wall or end structure of the piston seat 321, thereby providing elastic restoring force during the movement of the piston 322. In the assembled state, one end of the piston 322 forms mechanical contact with the moving part 31 by abutting, and this end serves as the driving end of the tension drive assembly 32, used to convert the axial displacement of the piston 322 into a pushing force on the moving part 31; the other end of the piston 322 abuts against the piston seat 321 to limit its movement direction and ensure stable force.

[0051] In actual operation, when compressed gas is input into the internal cavity of piston seat 321 through the inlet and outlet pipes, the gas pressure inside the cavity increases, pushing piston 322 to overcome the elastic force of elastic element 323 and move in a predetermined direction. This causes the driving end of piston 322 to continuously press against movable element 31, thereby applying a stable thrust to movable element 31. This thrust is further converted into rotational deformation by movable element 31, achieving tensioning and fastening of the steel sheet. When the external gas pressure decreases or exhaust occurs, elastic element 323, under its own elasticity, pushes piston 322 back to its original position, gradually releasing the tension from movable element 31, thus completing the release or adjustment of the tension. Through the synergistic effect of air pressure and elastic element 323, tension drive assembly 32 can achieve controllable output and flexible buffering of tension, avoiding excessive instantaneous force on movable element 31 due to rigid drive, which could affect the flatness or service life of the steel sheet.

[0052] like Figure 4 As shown, a monitoring and adjustment method for an SMT movable stencil suitable for automotive electronics is described. The method includes: S10. Based on the integrated sensing module, acquire the workpiece surface contour and test auxiliary information. The test auxiliary information includes at least spatial position information, bonding reference information and measurement status information. S20. Generate the corresponding workpiece surface height distribution features based on the workpiece surface contour and spatial position information; S30. Generate corresponding bonding gap evaluation parameters based on the workpiece surface contour and bonding reference information; S40. Generate corresponding measurement reliability features based on the workpiece surface contour and measurement status information; S50. Based on the workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics, generate corresponding gap adaptive decisions.

[0053] In this embodiment, the integrated sensing module in this monitoring and adjustment method refers to a detection unit integrated and installed on the SMT movable stencil structure. It is used to perform non-contact measurement of the actual surface state of the PCB after the stencil and the PCB to be printed are positioned, and outputs the measurement results to the control module in the form of electrical signals. This integrated sensing module can integrate a laser displacement detector, signal processing circuit, and interface unit, enabling the stencil system to acquire the true surface morphology of the PCB without contact, thus providing the original data basis for subsequent bonding and adjustment. The workpiece surface profile refers to the collection of PCB surface height or distance information acquired by the integrated sensing module at multiple detection positions. This profile reflects the overall undulation, local warping, or step changes of the PCB in the actual clamping state. It is not an ideal design plane, but rather reflects the true geometric shape of the PCB surface under actual working conditions.

[0054] Test auxiliary information refers to the set of supporting information acquired simultaneously with the acquisition of the workpiece surface contour to ensure that the contour data can be correctly interpreted and used. This test auxiliary information includes at least spatial position information, bonding reference information, and measurement status information. Spatial position information is used to characterize the positional relationship of each contour sampling data in the stencil or PCB coordinate system, so that different sampling points can correspond to specific spatial regions, thereby avoiding the contour data existing only as isolated values. Bonding reference information is used to describe the reference positional relationship between the stencil and the PCB under ideal bonding conditions. This reference information can be used to determine the degree of deviation between the actual contour and the ideal bonding state. Measurement status information is used to reflect the working status of the sensing module during the sampling process, such as whether the signal is valid, whether there is over-range or signal attenuation, thereby providing a basis for subsequent judgment on the reliability of the measurement data.

[0055] The height distribution characteristic of a workpiece surface refers to the characteristic result obtained by analyzing the height variation pattern in different spatial regions after obtaining the workpiece surface contour and combining it with spatial position information. This characteristic is used to reflect the height distribution state of the PCB surface in the whole or local areas, such as whether there is an overall tilting trend, local arching, or depression. This height distribution characteristic is not a simple single-point height value, but a comprehensive characteristic that can characterize the relative height relationship between multiple regions, providing a spatial reference for steel sheet bonding adjustment.

[0056] The bonding gap assessment parameter refers to a set of parameters that quantify the relative gap between the stencil and the PCB surface based on a known workpiece surface profile and bonding reference information. This parameter describes whether there is any suspension, overpressure, or insufficient bonding between the stencil and the PCB in different spatial regions. Through this bonding gap assessment parameter, the bonding state, which was originally difficult to judge intuitively, can be transformed into numerical or graded information that can be used for control decisions, thus providing a clear basis for applying or releasing pressure on the stencil.

[0057] Measurement reliability characteristics refer to the evaluation results formed after analyzing the effectiveness of workpiece surface contour data based on measurement status information. This characteristic reflects the comprehensive level of the current contour data in terms of continuity, stability, and reliability. By introducing measurement reliability characteristics, the control system can avoid making adjustment decisions directly based on unreliable data when there is abnormal measurement data or signal interference, thereby improving the robustness and safety of the entire monitoring and adjustment process.

[0058] Gap adaptive decision refers to the control result generated by the control module after comprehensively considering the height distribution characteristics of the workpiece surface, the bonding gap evaluation parameters, and the measurement reliability characteristics. This decision can determine whether bonding adjustment is needed and the direction, magnitude, or priority of the adjustment. Ultimately, it is used to drive actuators such as piezoelectric ceramics to apply corresponding displacement or pressure to the steel sheet, so that the steel sheet can maintain a reasonable bonding state with the PCB surface before or during actual printing.

[0059] For example, in an actual SMT printing operation, when the integrated sensing module scans a PCB with a slight central bulge, the acquired workpiece surface contour shows that the height of the central region is higher than that of the edge region. The spatial location information allows this height change to be accurately mapped to the corresponding central spatial region, and the height distribution characteristics thus characterize the local bulge trend of the PCB. At the same time, the bonding reference information indicates that the steel sheet should ideally be bonded to this region, and the bonding gap evaluation parameters thus reflect that there is insufficient bonding in the central region. If the measurement status information shows that the measurement data in this region is stable and reliable, the measurement reliability characteristic is in an effective state. After integrating the above characteristics, the control module generates a gap adaptive decision, driving the piezoelectric ceramic at the corresponding position to push the steel sheet downward slightly, so that the steel sheet achieves adaptive bonding with the PCB surface in this region, providing stable bonding conditions for subsequent solder paste printing.

[0060] Furthermore, the step of generating the corresponding workpiece surface height distribution features based on the workpiece surface contour and spatial location information includes: S201. The position of each contour sampling value in the obtained workpiece surface contour is calibrated so that the contour sampling value and the corresponding spatial position information are spatially associated. Each contour sampling value corresponds to a pre-divided spatial region. S202. Based on spatial correlation, arrange and map the height values ​​of the workpiece surface contour in different spatial regions to generate a corresponding height distribution description. S203. Based on the height distribution description, extract the height variation relationship between adjacent spatial regions to generate the corresponding workpiece surface height distribution features.

[0061] In this embodiment, the workpiece surface profile refers to the set of actual geometric shape information of the PCB surface to be printed, collected at multiple detection positions by the integrated sensing module. It reflects the actual height fluctuations of the PCB in its clamping and printing states, rather than the theoretically designed plane. Profile sampling values ​​refer to the discrete measurement data constituting the workpiece surface profile. Each sampling value corresponds to the height or distance measurement result at a specific detection position on the PCB surface. Spatial position information is used to characterize the positional attributes of each profile sampling value in the stencil or PCB coordinate system, enabling the sampling values ​​to be accurately mapped to specific spatial positions, rather than existing as isolated values. Position calibration refers to the process of matching profile sampling values ​​with spatial position information, ensuring that each profile sampling value has a clear spatial orientation. Spatial correlation is a correspondence formed after position calibration, used to characterize the mapping relationship between the profile sampling value and its spatial position or region.

[0062] A spatial region refers to several pre-divided analysis units on the stencil or PCB surface. Each spatial region carries one or more contour sampling values, facilitating a unified analysis of the height status within a local area. The height value refers to the numerical expression of the contour sampling value in the height direction after spatial association is completed, reflecting the relative height of the PCB surface within the corresponding spatial region. Arrangement mapping refers to the process of organizing the height values ​​in different spatial regions in an orderly manner based on spatial association relationships, allowing the height data to be arranged according to spatial distribution patterns. Height distribution description refers to the data structure or descriptive result formed after arrangement mapping, reflecting the height distribution status between various spatial regions. Height variation relationship refers to the height differences or trends exhibited between adjacent spatial regions in the height distribution description; this relationship is used to characterize the undulation features of the PCB surface within a local or overall range. The workpiece surface height distribution characteristics are a comprehensive feature result formed based on the extracted height variation relationships, used to characterize the height distribution morphology of the overall or local areas of the PCB surface, providing a spatial geometric basis for subsequent bonding adjustments.

[0063] Furthermore, the step of generating corresponding bonding gap evaluation parameters based on the workpiece surface contour and bonding reference information includes: S301. Perform benchmark alignment processing on the bonding benchmark information so that the bonding benchmark information and each height feature parameter in the height distribution description are in the same bonding reference system, thereby establishing the corresponding benchmark correspondence. S302. Based on the benchmark correspondence, compare each height feature parameter in the height distribution description with the corresponding fitting standard to generate a relative fitting gap description in each spatial region. S303. Based on the description of the relative fitting gap, summarize and characterize the fitting gap status of each spatial region, and generate corresponding fitting gap evaluation parameters.

[0064] In this embodiment, the bonding reference information refers to the reference information used to describe the relative positional relationship between the steel sheet and the PCB to be printed in an ideal bonding state. It can reflect the reference height or reference position that the steel sheet should be in when it is not adjusted or in the target bonding state. Reference alignment processing refers to unifying the coordinate system and reference plane of the bonding reference information and the height distribution description obtained in the previous step, so that the two can be compared under the same bonding reference system, thereby avoiding the deviation in bonding state judgment caused by inconsistent reference references. The height feature parameters in the height distribution description refer to the feature quantities used to characterize the height state in different spatial regions, which are derived from the results of spatial analysis of the workpiece surface contour. The reference correspondence relationship is a mapping relationship established after the reference alignment is completed, which is used to clarify the reference position or reference height corresponding to each height feature parameter under the bonding reference, thereby providing a unified basis for subsequent gap comparison.

[0065] The bonding standard refers to the pre-set or implicit reference conditions in the bonding reference information, used to determine whether the steel sheet and PCB are in a reasonable bonding state in various spatial areas. The relative bonding gap description refers to the descriptive result formed by comparing the height characteristic parameters with the corresponding bonding standard under the constraint of the reference correspondence relationship. It reflects the relative gap between the steel sheet and PCB in various spatial areas, which may manifest as insufficient bonding, excessive bonding, or near-ideal bonding. The bonding gap state refers to the state characterization of the bonding situation in different spatial areas based on the relative bonding gap description, used to reflect the distribution characteristics of the bonding degree in each area. The bonding gap evaluation parameter is a comprehensive parameter formed after summarizing and characterizing the bonding gap state of each spatial area. It is used to reflect the current bonding deviation level between the steel sheet and PCB as a whole and serves as an important input for subsequent adjustment decisions.

[0066] Furthermore, based on the workpiece surface contour and measurement status information, corresponding measurement reliability features are generated, including: S401. Perform state recognition processing on the measurement state information to determine the effective measurement state of each contour sampling value of the workpiece surface contour. Based on the preset measurement state threshold, compare the effective measurement state and generate the corresponding abnormal state identifier in the corresponding spatial area. S402. Based on the abnormal state identifier, determine the corresponding processing strategy. The processing strategy includes removing, correcting or compensating the contour sample values ​​to generate the corresponding valid contour data set. S403. Perform a continuous stability assessment on the effective contour data set and generate the corresponding measurement reliability features.

[0067] In this embodiment, measurement status information refers to auxiliary information synchronously output by the integrated sensing module during the acquisition of the workpiece surface contour. This information reflects whether the measurement process is in a normal working state and characterizes whether the measurement conditions corresponding to each contour sampling value meet the validity requirements. Status recognition processing refers to the process of analyzing and judging the measurement status information. This processing can distinguish the measurement status of different contour sampling values, such as whether there is insufficient signal, exceeding the measurement range, or interference. A valid measurement status refers to a sampling status that, after status recognition processing, is determined to meet preset measurement conditions and can truly reflect the surface morphology of the workpiece. The measurement status threshold is a reference limit used to distinguish whether a measurement status is valid. It can be set based on sensor performance parameters or experience and is used to determine whether the measurement status information falls within an acceptable range. An abnormal status identifier is a marking result formed after comparing the valid measurement status with the measurement status threshold, used to indicate whether abnormal measurement data exists in the corresponding spatial area.

[0068] Processing strategies refer to the data processing methods adopted for contour sample values ​​identified as abnormal, with the aim of reducing the impact of abnormal measurement data on the overall analysis results. Elimination processing involves removing contour sample values ​​that clearly do not meet the measurement conditions from subsequent calculations; correction processing involves adjusting the contour sample values ​​to bring them closer to a reasonable range, provided the degree of abnormality is controllable; compensation processing involves supplementing missing or abnormal data based on adjacent valid sample values ​​or historical data to maintain data continuity. The valid contour data set refers to the set of contour sample data retained after completing the above processing strategies, used for subsequent analysis. This set can preserve the workpiece surface morphology information as much as possible while ensuring data reliability.

[0069] Continuity stability assessment refers to the process of analyzing the continuity and stability of the effective contour data set in terms of spatial distribution and numerical variation. It is used to determine whether the processed contour data maintains a reasonable trend of change in adjacent spatial regions. Measurement reliability characteristics are the evaluation results formed after completing the continuity stability assessment. They are used to comprehensively reflect the overall reliability of the current workpiece surface contour data and serve as an important constraint for subsequent fitting adjustment decisions.

[0070] Furthermore, the step of generating the corresponding gap adaptive decision based on the workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics includes: S501. The workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics are weighted and fused according to preset weight coefficients to generate corresponding fused data. S502. Obtain the attribute data of the piezoelectric ceramic, map the corresponding constraints based on the attribute data, and generate the corresponding gap adaptive decision based on the constraints and fused data.

[0071] In this embodiment, the workpiece surface height distribution feature is a geometric feature result used to characterize the height variation trend of the PCB surface in different spatial regions, reflecting the undulation shape of the workpiece as a whole or in a local area; the bonding gap evaluation feature is an evaluation result used to describe the relative bonding degree between the steel sheet and the PCB in each spatial region, reflecting the spatial distribution of bonding deviation; the measurement reliability feature is an evaluation result used to characterize the reliability of the above geometric and bonding data under the current working conditions, reflecting whether the relevant feature data is suitable for direct participation in adjustment decisions. The weighting coefficient is a proportional parameter set according to the importance of different features in the decision-making process, used to adjust the influence of various features in the fusion calculation. Weighted fusion refers to the process of comprehensively calculating the workpiece surface height distribution feature, bonding gap evaluation feature, and measurement reliability feature under the constraint of the weighting coefficient, thereby generating fused data that can simultaneously reflect geometric state, bonding deviation, and data reliability.

[0072] The attribute data of piezoelectric ceramics refers to parameter information related to the performance of piezoelectric ceramics, which describes the displacement range, response characteristics, or stress capacity that piezoelectric ceramics can achieve during actual operation. Constraints refer to the execution boundaries mapped from the piezoelectric ceramic attribute data, used to limit the allowable displacement amplitude or adjustment rate during adjustment to prevent adjustment commands from exceeding the physical load-bearing capacity of the piezoelectric ceramic. Gap adaptive decision-making, under the premise of satisfying constraints, combines the adjustment results generated from fused data to determine whether the bonding gap between the steel sheet and the PCB needs adjustment, and the corresponding adjustment direction and degree.

[0073] Specifically, the control of the piezoelectric ceramic is accomplished by the control module in a closed-loop manner. After obtaining the gap adaptive decision, the control module first parses the decision into driving command parameters that match the physical characteristics of the piezoelectric ceramic. These driving command parameters include at least the target displacement, the application direction, and the timing of the action. Based on the driving characteristics of the piezoelectric ceramic, the control module converts the target displacement into a corresponding voltage amplitude or voltage change, and applies a controlled electrical signal to the piezoelectric ceramic through the driving circuit, causing the piezoelectric ceramic to undergo corresponding elongation or contraction deformation along its polarization direction. To avoid instantaneous impact or over-adjustment, the control module uses a gradual or graded loading method when outputting the driving signal, making the deformation process of the piezoelectric ceramic smooth and controllable, thereby stably transmitting the adjustment force to the steel sheet. While the piezoelectric ceramic is performing adjustment actions, the integrated sensing module continuously monitors the surface condition of the workpiece. The control module compares the measurement results before and after adjustment in real time. When the bonding state between the steel sheet and the PCB is detected to be within the expected range or close to the target bonding state, the control module promptly reduces or stops the drive output to the piezoelectric ceramic to maintain the current bonding state. If the detection results still have deviations, the drive command is corrected based on the new measurement data, and the above control process is repeated. This achieves continuous, controllable, and adaptive drive of the piezoelectric ceramic, allowing the bonding process between the steel sheet and the PCB to gradually converge to the ideal state within safety constraints.

[0074] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A movable stencil for automotive electronics, characterized in that, The aforementioned SMT movable stencil suitable for automotive electronics includes: The side sealing plate (1) has four in total, and each pair is connected end to end by a right angle joint (2) to form a corresponding rectangular frame; Steel sheet fixing components (3) are located inside each of the side sealing plates (1) for mounting and engaging with the steel sheet; An integrated sensing module (4) is located on one side of the steel sheet fixing component (3) and is used to obtain the workpiece surface contour of the PCB to be printed. The piezoelectric ceramic (5) has one end located inside the side sealing plate (1) and the other end passing through the side sealing plate (1) and dynamically connected to the steel sheet; The control module is electrically connected to the integrated sensing module (4) and the piezoelectric ceramic (5) respectively, and is used to generate a corresponding gap adaptive decision based on the surface contour of the workpiece. The gap adaptive decision is used to control the piezoelectric ceramic (5) to push down against the steel sheet so that the steel sheet and the PCB to be printed are adaptively bonded and matched.

2. The SMT movable stencil suitable for automotive electronics according to claim 1, characterized in that, The side sealing plate (1) is provided with a fixing strip (6), which is perpendicularly connected to the piezoelectric ceramic (5). The side sealing plate (1) is provided with a detection through hole (11). The side of the fixing strip (6) away from the side sealing plate (1) is an inclined surface, which is connected to the integrated sensing module (4) so ​​that the detection end of the integrated sensing module (4) is correspondingly set with the detection through hole (11).

3. The SMT movable stencil suitable for automotive electronics according to claim 2, characterized in that, The integrated sensing module (4) includes at least one EMOS laser displacement sensor.

4. The SMT movable stencil suitable for automotive electronics according to claim 1, characterized in that, The steel sheet fixing component (3) includes a movable part (31) and a tensioning drive assembly (32). The drive end of the tensioning drive assembly (32) abuts against one end of the movable part (31) to cause the movable part (31) to rotate and deform, thereby causing the other end of the movable part (31) to fasten the steel sheet. The other end of the movable part (31) is provided with a chamfer that is turned outward towards the outside of the rectangular frame.

5. The SMT movable stencil for automotive electronics according to claim 4, characterized in that, The tensioning drive assembly (32) includes a piston seat (321), a piston (322), and an elastic element (323). The piston seat (321) is located on one side of the movable element (31). The piston seat (321) has a cavity and an inlet / outlet pipe communicating with the cavity. The piston (322) is located in the cavity and is sleeved with the elastic element (323) so that one end of the piston (322) abuts against the movable element (31) to serve as the drive end of the tensioning drive assembly (32), and the other end of the piston (322) abuts against the piston seat (321).

6. A monitoring and adjustment method for SMT movable stencils suitable for automotive electronics, characterized in that, The monitoring and adjustment method, applied to an SMT movable stencil suitable for automotive electronics as described in any one of claims 1-5, comprises: Based on the integrated sensing module, the workpiece surface contour and test auxiliary information are acquired. The test auxiliary information includes at least spatial position information, fitting reference information and measurement status information. Based on the workpiece surface contour and the spatial position information, a corresponding workpiece surface height distribution feature is generated; Based on the workpiece surface contour and the bonding reference information, corresponding bonding gap evaluation parameters are generated; Based on the workpiece surface contour and the measurement state information, a corresponding measurement reliability feature is generated; Based on the workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics, a corresponding gap adaptive decision is generated.

7. The monitoring and adjustment method for SMT movable stencils suitable for automotive electronics according to claim 6, characterized in that, The step of generating corresponding workpiece surface height distribution features based on the workpiece surface contour and the spatial position information includes: The position of each contour sampling value in the acquired workpiece surface contour is calibrated so that the contour sampling value is spatially associated with the corresponding spatial position information, wherein each contour sampling value corresponds to a pre-divided spatial region. Based on the spatial relationship, the height values ​​of the workpiece surface contour in different spatial regions are arranged and mapped to generate a corresponding height distribution description. Based on the height distribution description, the height variation relationship between adjacent spatial regions is extracted to generate the corresponding workpiece surface height distribution features.

8. The monitoring and adjustment method for SMT movable stencils suitable for automotive electronics according to claim 7, characterized in that, The step of generating corresponding bonding gap evaluation parameters based on the workpiece surface contour and the bonding reference information includes: The fitting reference information is subjected to reference alignment processing so that the fitting reference information and each height feature parameter in the height distribution description are in the same fitting reference system, thereby establishing a corresponding reference correspondence. Based on the aforementioned benchmark correspondence, each height feature parameter in the height distribution description is compared with the corresponding fitting standard to generate a relative fitting gap description for each spatial region. Based on the description of the relative fitting gap, the fitting gap status of each spatial region is summarized and characterized to generate corresponding fitting gap evaluation parameters.

9. A monitoring and adjustment method for SMT moving stencils suitable for automotive electronics according to claim 6, characterized in that, The step of generating corresponding measurement reliability features based on the workpiece surface contour and the measurement state information includes: The measurement status information is processed for status recognition to determine the effective measurement status of each contour sampling value of the workpiece surface contour. Based on the preset measurement status threshold, the effective measurement status is compared and a corresponding abnormal status identifier is generated in the corresponding spatial region. Based on the abnormal state identifier, a corresponding processing strategy is determined. The processing strategy includes removing, correcting, or compensating the contour sample values ​​to generate a corresponding valid contour data set. The continuous stability of the effective contour data set is assessed to generate corresponding measurement confidence features.

10. A monitoring and adjustment method for SMT moving stencils suitable for automotive electronics according to claim 6, characterized in that, The step of generating corresponding gap adaptive decisions based on the workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics includes: The workpiece surface height distribution characteristics, fitting gap evaluation characteristics, and measurement reliability characteristics are weighted and fused according to preset weighting coefficients to generate corresponding fused data; Obtain the attribute data of the piezoelectric ceramic, map the corresponding constraints based on the attribute data, and generate the corresponding gap adaptive decision based on the constraints and the fused data.

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