A roll-to-roll double-sided synchronous exposure system and device for precision metal strips

Abstract

The present application relates to the field of photolithography microelectronic manufacturing and automation equipment technology, and discloses a roll-to-roll double-sided synchronous exposure system and device for precision metal tape, which aims to solve the problems of deformation and physical damage of the tape caused by the step-by-step start-stop in the existing roll-to-roll double-sided exposure equipment, and the difficulty in adapting to dynamic deformation in the continuous transmission state, thereby leading to overlay deviation. The tape is kept in contactless suspension in continuous transmission by airflow lifting; the small deformation amount of the tape is calculated in advance according to the real-time tension and temperature data of the tape; the exposure machine is driven to move synchronously with the tape, and the mask is fine-tuned to perform double-sided exposure in combination with the deformation amount and the position deviation recognized by the camera; and the calculation error is automatically corrected by using the detection data after exposure. The present application avoids mechanical friction damage, and effectively improves the alignment accuracy of double-sided exposure in the continuous running state without shutdown.

Description

Technical Field

[0001] This invention relates to the field of photolithography microelectronics manufacturing and automation equipment technology, specifically, to a roll-to-roll double-sided synchronous exposure system and apparatus for precision metal strips. Background Technology

[0002] With the rapid development of flexible printed circuit boards, high-density integrated circuit lead frames, and microelectromechanical systems (MEMS), the demand for high-precision double-sided patterning of thin metal strips (such as rolled copper foil and stainless steel strips) is surging. Roll-to-roll manufacturing technology has become the mainstream process in this field due to its advantages of continuous and high-volume production. In the roll-to-roll lithography process, double-sided exposure is the most critical step determining the yield of the final product. It not only requires uniform beam energy distribution but also extremely high-precision spatial alignment between the mask and the target on both sides of the metal roll. Currently, most conventional roll-to-roll double-sided exposure equipment in the industry adopts a stepping operation mode or a continuous transmission mode based on rigid friction contact.

[0003] However, existing roll-to-roll double-sided exposure technology faces an irreconcilable contradiction between efficiency and precision in actual mass production. On the one hand, traditional step-type exposure requires the equipment to frequently perform a cycle of conveyor belt feeding-stopping-clamping-exposure-releasing. Frequent starts and stops cause huge mechanical inertial impacts and drastic changes in transmission tension, inevitably leading to irreversible microscopic stretching deformation of the extremely thin metal strip. Furthermore, repeated rigid contact easily causes scratches and peeling of the photoresist coating on the strip surface. On the other hand, if continuous transmission exposure is used without stopping the machine, the metal strip is constantly affected by the residual heat and traction force from previous processes during long-distance transmission, resulting in complex dynamic changes in its microscopic physical dimensions. Existing fixed or conventional mechanical tracking exposure mechanisms cannot adapt to this dynamic physical deformation in real time, leading to micrometer-level overlay deviations in the latent images on both sides of the strip. Therefore, how to effectively overcome the dynamic microscopic deformation of the material and mechanical jitter interference under high-efficiency continuous transmission conditions to achieve extremely high-precision double-sided dynamic alignment and non-destructive exposure has become a pressing technical bottleneck for the precision manufacturing industry. Summary of the Invention

[0004] In view of the problems in existing roll-to-roll double-sided exposure equipment, such as the tendency of stepper start-stop to cause tape deformation and physical damage, and the difficulty in adapting to dynamic deformation during continuous transport, leading to overlay deviations, the present invention provides the following technical solution to solve the above technical problems: This invention provides a roll-to-roll double-sided synchronous exposure method for precision metal strips, comprising the following steps: S1. A non-contact double-sided clamping method is used to hold the precision metal strip coated with photosensitive material through a gas pressure field, and the precision metal strip is driven to be continuously transported along a preset path. S2. Before the precision metal strip is transferred into the exposure station, the real-time tension parameters and surface temperature distribution parameters of the precision metal strip are collected simultaneously. S3. Combine the real-time tension parameters and the surface temperature distribution parameters to perform deformation calculation and obtain the micro-deformation compensation amount of the precision metal strip in the exposure station. S4. Simultaneously acquire the alignment target images of the front and back surfaces of the precision metal roll and the reference target images of the mask plates placed on both sides of the precision metal roll using the dual-sided optical imaging components. S5. Combining the micro-deformation compensation amount and the positional deviation between the alignment target image and the reference target image, calculate the multi-degree-of-freedom spatial pose adjustment command. S6. According to the multi-degree-of-freedom spatial pose adjustment command, drive the mask to move synchronously along the transmission direction of the precision metal strip, and perform double-sided synchronous exposure within a relatively static follow-up period.

[0005] As a preferred embodiment of the roll-to-roll double-sided synchronous exposure method for precision metal strips according to the present invention, wherein: the process of non-contact double-sided clamping of the precision metal strip coated with photosensitive material by means of a gas pressure field in step S1 includes: synchronously spraying clean gas medium of equal pressure onto the upper and lower surfaces of the precision metal strip, constructing gas support films of equal thickness on both sides of the precision metal strip, and constraining the normal displacement of the precision metal strip in the direction perpendicular to the transmission direction.

[0006] As a preferred embodiment of the roll-to-roll double-sided synchronous exposure method for precision metal strips described in this invention, the process of synchronously acquiring the real-time tension parameters and surface temperature distribution parameters of the precision metal strip in step S2 includes: continuously acquiring dynamic tensile force data along the axial direction of the precision metal strip using a contact tension sensing component, and filtering out the periodic jitter interference amplitude caused by the transmission power source during data acquisition; and simultaneously scanning the thermal radiation signal on the surface of the precision metal strip using an infrared thermal imaging component to construct a two-dimensional temperature gradient matrix reflecting the superposition of residual temperature from previous processes and ambient airflow interference.

[0007] As a preferred embodiment of the roll-to-roll double-sided synchronous exposure method for precision metal strips according to the present invention, the process of performing deformation calculation and obtaining the micro-deformation compensation amount of the precision metal strip in the exposure station in step S3 includes: based on the real-time tension parameter and the elastic modulus of the precision metal strip, calculating the mechanical tensile deformation value of the precision metal strip in the axial direction using the following mechanical formula. :

[0008] in, The real-time tension parameter is... The effective transmission segment length of the exposure station is [length]. The elastic modulus of the precision metal strip is given by [reference needed]. The cross-sectional area of ​​the precision metal strip is given; based on the surface temperature distribution parameters and the thermal expansion coefficient of the precision metal strip, the thermodynamic expansion deformation value is calculated using the following thermodynamic formula. :

[0009] in, The coefficient of thermal expansion of the precision metal strip is given. The change in surface temperature distribution parameters relative to a preset reference temperature; the mechanical tensile deformation value. With the aforementioned thermodynamic expansion deformation value Spatial vector superposition is performed to generate the microscopic deformation compensation amount.

[0010] As a preferred embodiment of the roll-to-roll double-sided synchronous exposure method for precision metal strips described in this invention, the process of synchronously acquiring images in step S4 includes: emitting illumination beams to the precision metal strip and the mask using a polarized coaxial light source; and performing feature fitting on the acquired images using a sub-pixel edge extraction algorithm to extract the true geometric center coordinates of the alignment target and the reference target.

[0011] As a preferred embodiment of the roll-to-roll double-sided synchronous exposure method for precision metal strips described in this invention, the process of calculating the multi-degree-of-freedom spatial pose adjustment command in step S5 includes: performing lens distortion correction and incomplete feature repair on the acquired alignment target image and the reference target image, and extracting the true geometric center deviation; injecting the micro-deformation compensation amount as a feedforward offset into the true geometric center deviation amount, and generating the multi-degree-of-freedom spatial pose adjustment command containing the expected deformation compensation.

[0012] As a preferred embodiment of the roll-to-roll double-sided synchronous exposure method for precision metal strips according to the present invention, the process of driving the mask to synchronously follow the transmission direction of the precision metal strip in step S6 and performing double-sided synchronous exposure within a relatively static follow-up period includes: controlling the translation drive component carrying the mask to accelerate in the same direction along the transmission direction based on the real-time transmission speed parameters of the precision metal strip; establishing a relatively static follow-up window when the acceleration is consistent with the real-time transmission speed parameters; within the follow-up window, triggering the multi-axis micro-motion component to perform the six-degree-of-freedom synchronous correction of the mask on the upper and lower sides, including planar translation, planar rotation and spatial pitch attitude adjustment, according to the multi-degree-of-freedom spatial pose adjustment command; synchronously adjusting the illumination radiation intensity of the exposure light source to maintain the cumulative exposure dose per unit area received by the surface of the precision metal strip as a constant value.

[0013] As a preferred embodiment of the roll-to-roll double-sided synchronous exposure method for precision metal strips according to the present invention, step S6, after performing double-sided synchronous exposure, further includes: after completing the double-sided synchronous exposure, performing overlay accuracy detection on the front and back exposure patterns of the precision metal strip to obtain overlay deviation data; and using a filtering algorithm to remove random jump data from the overlay deviation data and extract system drift data. Using the system drift data combined with the transmission path delay compensation coefficient, the following iterative correction algorithm is employed to calculate the basic weighting coefficients for the micro-deformation compensation amount. Make corrections and adjustments:

[0014] in, This serves as the base weighting coefficient for the next exposure cycle after the update. This is the base weighting coefficient for the current exposure cycle. The transmission path delay compensation coefficient is... This refers to the system drift data.

[0015] The present invention also provides a roll-to-roll double-sided synchronous exposure system for precision metal strips, characterized in that the system is equipped with a computing device adapted to implement the roll-to-roll double-sided synchronous exposure method for precision metal strips as described in any one of claims 1 to 8.

[0016] The present invention also provides a roll-to-roll double-sided synchronous exposure apparatus for precision metal strips, used to perform the above method and as the execution carrier of the above system, specifically comprising: A transmission support unit, comprising a base, with an unwinding mechanism and a winding mechanism respectively provided at both ends of the base, and a tension guide roller group distributed between the unwinding mechanism and the winding mechanism; The follow-up exposure unit includes a drive mechanism disposed in the middle section of the base, a main frame slidably disposed at the top of the drive mechanism, an exposure machine symmetrically disposed above and below the main frame, an ultraviolet exposure light source disposed at the top of the exposure machine, and a porous static pressure air flotation array disposed at the bottom of the exposure machine. The sensing and detection unit includes a contact tension sensor movably mounted on the tension guide roller assembly; an infrared thermal imager suspended on the feed side of the base via a bracket; an alignment camera fixedly mounted on the follower main frame; and an overlay detection camera fixed on the discharge side of the base via a frame.

[0017] The beneficial effects of this invention are as follows: This invention uses airflow to keep the conveyor belt suspended without contact during continuous transport; based on real-time tension and temperature data of the conveyor belt, it pre-calculates the minute deformation of the belt; it drives the exposure machine to move synchronously with the conveyor belt, and combines this deformation with the positional deviation detected by the camera to fine-tune the mask for double-sided exposure; simultaneously, it automatically corrects calculation errors using post-exposure detection data. This invention avoids mechanical friction damage and effectively improves the alignment accuracy of double-sided exposure in continuous operation without shutdown. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a roll-to-roll double-sided synchronous exposure method for precision metal strips.

[0020] Figure 2 The logic block diagram for calculating the micro-deformation compensation amount.

[0021] Figure 3 A flowchart for establishing a control process for simultaneous double-sided exposure of a relatively stationary follow-up window.

[0022] Figure 4 This is a flowchart of the adaptive closed-loop iteration process.

[0023] Figure 5 This is an overall view of a roll-to-roll double-sided synchronous exposure apparatus for precision metal strips.

[0024] Figure 6 This is a front view of a roll-to-roll double-sided synchronous exposure apparatus for precision metal strips. Detailed Implementation

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "one embodiment" or "example" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. The appearance of an embodiment in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments. Example 1

[0028] Reference Figures 1-3 This is one embodiment of the present invention, which provides a roll-to-roll double-sided synchronous exposure method for precision metal strips, comprising the following steps: S1. The precision metal strip coated with photosensitive material is clamped in a non-contact double-sided manner by a gas pressure field, and the precision metal strip is driven to be continuously transported along a preset path. Clean gas media of equal pressure are synchronously sprayed onto the upper and lower surfaces of the precision metal strip to construct a gas support film of uniform thickness on both sides of the precision metal strip, thereby constraining the normal displacement of the precision metal strip perpendicular to the transmission direction.

[0029] In the actual continuous processing line, the precision metal strip is connected to unwinding and rewinding servo mechanisms at both ends, thus constructing a horizontal preset path that maintains constant tension. As the precision metal strip continuously traverses the core exposure area along this preset path, the system constructs a non-contact gas pressure field through a symmetrically arranged array of porous hydrostatic air bearings before and after the workstation. The bearing array is typically made of ceramic material with an average pore size reaching micron-level throttling standards. During operation, industrial pure gas with an ultrafiltration accuracy of 0.1μm is continuously injected via a precision electro-proportional valve to form a matching preset pressure. In this embodiment, the preset pressure is precisely controlled within the range of 0.3MPa to 0.5MPa. This is because the airflow within this pressure range provides sufficient gas lifting force to overcome the weight of the precision metal strip while effectively preventing high-frequency aerodynamic vibration induced on the strip surface due to input pressure overload. The gas is uniformly released through the micropores, supporting a gas-supported membrane of a set thickness between the upper and lower surfaces of the precision metal strip and the bearing surface. In this embodiment, the thickness of the gas-supported membrane is set to 15 μm to 30 μm. This is because when the gas film gap is compressed to this micrometer range, the viscous shear force and hydrostatic effect of the gas reach optimal coupling, providing extremely high gas film stiffness. Due to this high stiffness, once the precision metal strip is subjected to a slight external disturbance and exhibits a tendency for normal displacement, the pressure on the compressed side of the gas gap will surge and generate a strong restoring force, thereby strictly locking the normal runout amplitude of the precision metal strip within a certain range. Within the tolerance range, extremely high precision suspension guidance is achieved.

[0030] S2. Before the precision metal strip is transported into the exposure station, the real-time tension parameters and surface temperature distribution parameters of the precision metal strip are collected simultaneously. The dynamic tensile force data along the axial direction of the precision metal strip is continuously acquired using a contact-type tension sensing component, and the periodic jitter interference amplitude caused by the transmission power source is filtered out during data acquisition. Simultaneously, the thermal radiation signal on the surface of the precision metal strip is scanned using an infrared thermal imaging component to construct a two-dimensional temperature gradient matrix that reflects the superposition of interference between the residual temperature of the previous process and the ambient airflow.

[0031] Before the precision metal strip enters the core exposure station, the system continuously monitors the dynamic force on the strip along its axial direction using a force sensor guide roller installed at the entrance of the transmission channel, and outputs corresponding analog electrical signals. Considering that the servo motor inevitably generates cogging torque fluctuations during operation, resulting in high-frequency mechanical vibration noise mixed in the acquired signals, the system introduces a digital low-pass filtering algorithm with a cutoff frequency set to a specific value at the signal processing front end. In this embodiment, to accurately remove high-frequency noise interference while retaining low-frequency macroscopic tension fluctuations reflecting the true tensile state, the system uses the following first-order discrete low-pass filtering formula to perform frequency domain cleaning on the original acquired signal:

[0032] in, This is the currently extracted baseline tension value. The raw dynamic tensile force data acquired by the current tension sensing component. This is the reference tension value from the previous sampling period. To match the preset A smoothing coefficient matching the cutoff frequency and system sampling rate is used. After frequency domain cleaning, the system extracts the true reference tension value. Simultaneously, a planar infrared thermal imager covering the full width of the precision metal strip scans its surface thermal radiation. The thermal imager performs orthogonal spatial discretization processing on the captured continuous thermal radiation energy spectrum to construct a two-dimensional temperature gradient matrix. Specifically, the two-dimensional temperature gradient matrix defines the lateral width of the precision metal strip as the X-axis feature dimension and the axial transmission direction of the strip as the Y-axis feature dimension. This ensures that each element in the matrix accurately corresponds to the absolute temperature value of a specific physical grid on the strip surface, thus digitizing the chaotic thermal radiation distribution into a temperature fluctuation pattern with clear physical coordinates. In this embodiment, the physical grid is divided into a 1mm × 1mm micro-region. This spatial resolution, while accommodating the computational load of current industrial computing equipment, can accurately capture local microscopic thermal jumps (i.e., temperature gradient peaks) caused by factors such as light leakage at the edge of the ultraviolet exposure lamp, providing optimally granular data support for subsequent deformation prediction.

[0033] S3. Combine real-time tension parameters and surface temperature distribution parameters to calculate deformation and obtain the micro-deformation compensation amount of the precision metal strip in the exposure station. Based on real-time tension parameters and the elastic modulus of the precision metal strip, the axial mechanical tensile deformation value of the precision metal strip is calculated using the following mechanical formula. :

[0034] in, For real-time tension parameters, The effective transmission segment length of the exposure station. The elastic modulus of precision metal strip. Let be the cross-sectional area of ​​the precision metal strip; based on the surface temperature distribution parameters and the thermal expansion coefficient of the precision metal strip, the thermodynamic expansion deformation value is calculated using the following thermodynamic formula. :

[0035] in, The coefficient of thermal expansion of precision metal strip. The change in surface temperature distribution parameters relative to a preset reference temperature; the mechanical tensile deformation value. With thermodynamic expansion deformation value Spatial vector superposition is performed to generate microscopic deformation compensation.

[0036] Based on the acquired high-precision physical data, the system initiates the deformation calculation process according to the principles of continuum mechanics and thermodynamics. The algorithm module first allocates the cross-sectional area of ​​the target strip and its factory-calibrated elastic modulus, and couples it with the newly acquired reference tension data. In this embodiment, the system derives the mechanical tensile deformation value of the strip in the longitudinal direction within the effective exposure range using the following mechanical formula. :

[0037] in, The reference tension value is extracted in step S2. The effective transmission segment length of the exposure station. The elastic modulus of precision metal strip. This represents the cross-sectional area of ​​the precision metal strip. Subsequently, the system extracts the temperature difference data of each grid in the two-dimensional temperature gradient matrix and compares it with a preset environmental reference temperature. In this embodiment, the environmental reference temperature is set to 22℃ because the standard photolithography process is strictly locked at 22℃, and using this as a comparison benchmark can eliminate static interference caused by ambient heat. The system calculates the thermodynamic expansion deformation value of each micro-region under heated conditions using the following thermodynamic formula. :

[0038] in, The coefficient of thermal expansion of precision metal strip. This represents the temperature difference change deviating from the preset reference temperature of 22℃. Finally, the algorithm places the unidirectional tensile deformation vector and the isotropic thermal expansion deformation vector in the same coordinate system and performs spatial vector superposition to accurately predict the actual physical position that any feature point on the tape surface will reach when the exposure action is triggered, generating a microscopic deformation compensation amount.

[0039] S4. Simultaneously acquire the alignment target images of the front and back surfaces of the precision metal roll and the reference target images of the mask plates placed on both sides of the precision metal roll through the dual-sided optical imaging components. A polarized coaxial light source is used to emit an illumination beam toward a precision metal roll and a mask; the acquired image is fitted with features using a sub-pixel edge extraction algorithm to extract the true geometric center coordinates of the alignment target and the reference target.

[0040] As deformation prediction is completed, high-frame-rate industrial camera arrays positioned on the upper and lower sides of the exposure mechanism begin synchronous image capture. Addressing the physical challenge of specular and diffuse reflection caused by light penetrating the mask and striking the highly reflective metal strip, the system employs a polarization coaxial light source. This source incorporates polarization and analysis structures to ensure the illumination light aligns with the camera's optical axis and allows only effective imaging light with specific polarization directions to enter the lens. After acquiring a clear target image, given that traditional pixel-level grayscale peak positioning cannot meet micrometer-level alignment requirements, the system invokes a pre-defined sub-pixel edge extraction algorithm. In this embodiment, the sub-pixel edge extraction algorithm specifically employs a Gaussian surface fitting algorithm. This is because the Gaussian surface model closely matches the grayscale gradient distribution characteristics of the coaxial beam at the physical edge of the mask target due to diffraction in the optical imaging system. By performing polynomial interpolation calculations on the pixel grayscale gradients of the target edge, the resolution limit of the physical pixel grid is broken, dramatically improving the positioning accuracy of the target's true geometric center coordinates to the sub-micrometer level.

[0041] S5. Combine the micro-deformation compensation amount and the positional deviation between the aligned target image and the reference target image to calculate the multi-degree-of-freedom spatial pose adjustment command. Lens distortion correction and incomplete feature repair are performed on the acquired alignment target image and reference target image to extract the true geometric center deviation. The micro deformation compensation is injected as a feedforward offset into the true geometric center deviation to generate a multi-degree-of-freedom spatial pose adjustment command containing the expected deformation compensation.

[0042] In this process, after obtaining the actual geometric center deviation, the system injects the micro-deformation compensation calculated in step S3 as a feedforward offset. To accurately convert the calculated deviation into the subsequent mechanical motion of the piezoelectric micro-motion platform, the system uses the following rigid body kinematic transformation matrix to solve for the target spatial pose of the mask when generating multi-degree-of-freedom spatial pose adjustment commands:

[0043] in, These are the current actual coordinates. For the target expected coordinates, and This means incorporating the planar translation compensation component after deformation compensation prediction. This command compensates for the spatial rotational component of the angle between the mask and the tape. It ensures that the multi-axis micro-motion assembly precisely drives the mask to its final, accurate position after tape deformation compensation.

[0044] S6. According to the multi-degree-of-freedom spatial pose adjustment command, drive the mask to move synchronously along the transmission direction of the precision metal strip, and perform double-sided synchronous exposure within the relatively static follow-up cycle. Based on the real-time transmission speed parameters of the precision metal strip, the translation drive component carrying the mask is controlled to accelerate in the same direction along the transmission direction; when the acceleration reaches the same speed as the real-time transmission parameters, a relatively static follow-up window is established; within the follow-up window, according to the multi-degree-of-freedom spatial pose adjustment command, the multi-axis micro-motion component is triggered to perform six-degree-of-freedom synchronous correction on the mask on the upper and lower sides, including planar translation, planar rotation, and spatial pitch attitude adjustment; the illumination radiation intensity of the exposure light source is adjusted synchronously to maintain the cumulative exposure dose per unit area received by the surface of the precision metal strip at a constant value.

[0045] After completing the double-sided synchronous exposure, the overlay accuracy of the exposed patterns on the front and back sides of the precision metal strip is checked to obtain overlay deviation data. In this closed-loop feedback loop, to achieve the complete construction and stable updating of the high-precision deformation calculation model, the system executes the following depth-adaptive logic: First, the system constructs a spatial position mapping mechanism based on encoder pulses. Since roll-to-roll transmission involves spatial span, the currently detected deviation corresponds to previously exposed strip material. Therefore, the system uses pulse sequence backtracking to precisely align the currently acquired overlay deviation data with the original tension data and temperature matrix corresponding to the strip segment where the deviation occurred in step S3, thus completing the dataset construction required for model updates.

[0046] Secondly, for the acquired overlay deviation data, the system calls a preset sliding window filtering algorithm to remove transient random jump data caused by occasional mechanical vibrations and extract system drift data that reflects material batch tolerances or long-term equipment wear. .

[0047] In the initial stage of constructing the deformation calculation model, the system has assigned initial basic weight coefficients to each physical component of the calculation of micro-deformation compensation amount according to the standard material property handbook. To endow the system with adaptive learning capabilities and completely offset system drift data, the system employs the following exponentially weighted moving average iterative algorithm to adjust the current base weight coefficients. Make corrections and adjustments:

[0048] in, This serves as the base weighting coefficient for the next exposure cycle after the update. This is the base weighting coefficient for the current exposure cycle. This is a compensation coefficient related to transmission path delay.

[0049] Furthermore, in the construction logic of the deformation calculation model, the system also introduces a weight update boundary constraint mechanism. To prevent extreme deviation data output due to occasional anomalies in the detection equipment (such as misjudgment caused by lens dust), which could lead to model iteration divergence, the system will judge the system drift data before performing correction adjustments. Whether it is within the preset model confidence interval limit. Only when the system drift data... The closed-loop iteration of the weighting coefficients can only be triggered if the confidence interval limit is not breached. Through this mechanism, the system not only achieves the continuous evolution of the high-precision alignment operation model, but also ensures the convergence and stability of the entire operation logic in long-cycle, high-frequency industrial production. Example 2

[0050] Reference Figure 4 This is a second embodiment of the present invention, which provides a roll-to-roll double-sided synchronous exposure system for precision metal strips. The system is equipped with a computing device configured to perform the roll-to-roll double-sided synchronous exposure method for precision metal strips as described in Embodiment 1.

[0051] System Hardware Architecture and Control Center: In this embodiment, the system adopts a distributed control architecture based on industrial Ethernet (such as EtherCAT). The computing device serves as the control core of the system, and is electrically connected to the unwinding servo driver, the winding servo driver, the linear motor driver, the piezoelectric micro-motion platform controller, and the ultraviolet light source controller via a high-speed bus. In this embodiment, an industrial computer with multi-core parallel processing capabilities is selected as the computing device, and a high-performance graphics processing unit (GPU) is externally connected. This is because the system needs to simultaneously process sub-pixel-level image data captured by multiple high-frame-rate industrial cameras and perform complex two-dimensional spatial transformation matrix operations in real time. The parallel computing architecture of the GPU can significantly reduce data processing latency and ensure alignment accuracy.

[0052] System Model Construction and Logical Coordination: The computing device internally includes a data processing module, a deformation calculation module, a follow-up alignment module, and a closed-loop feedback module. Their coordination logic is as follows: Data Acquisition and Synchronous Construction: The system uses a synchronous trigger controller to ensure that the tension sensor, infrared thermal imager, and CCD camera complete data acquisition at the same timestamp. In this embodiment, the system sets the data acquisition frequency to above 1000Hz because, during high-speed transmission of the tape (e.g., at speeds greater than 10m / min), only a millisecond-level sampling period can capture the microsecond-level instantaneous deformation caused by tension fluctuations, providing accurate initial input for model construction.

[0053] Deformation calculation model operation: The computing device receives the tension and temperature matrices from the sensors. The deformation calculation module calls a preset material database (including elastic modulus and coefficient of thermal expansion), combines the extracted baseline tension value with the temperature gradient matrix, and performs a physical field coupling calculation covering mechanical tension and thermodynamic expansion. In this embodiment, the system automatically matches different algorithm weights according to the material of the current tape (such as stainless steel or copper alloy). This is because different materials have significantly different sensitivities to heat. By dynamically matching parameters, the accuracy of deformation prediction can be improved to over 95%.

[0054] Closed-loop adaptive learning mechanism: After each exposure cycle, the system transmits the deviation back through the rear AOI detector. In this embodiment, a long-term performance database based on an exponentially weighted moving average iterative algorithm is constructed within the system. The system not only updates the current basic weight coefficients but also records the deviation curves of the equipment under different ambient temperatures and operating times. This is because the mechanical characteristics of the equipment exhibit thermal drift during the startup phase (cold machine) and after several hours of operation (hot machine). By constructing this full-cycle temperature drift model, the system can achieve automatic accuracy compensation across time periods, ensuring high consistency of the system under all-weather operation.

[0055] External Interface and Safety Assurance: In addition, the system is equipped with a human-machine interface for preset material parameters and monitoring real-time alignment status. In this embodiment, the system incorporates redundant protection logic in its computing device. If the gas pressure field pressure is detected to be below the critical value of 0.25 MPa, the system will immediately trigger an emergency shutdown and lock the mask support. This is because failure of the air flotation pressure would cause the precision metal strip to fall instantly and collide with the mask, resulting in expensive mask damage and strip scrap. This dual hardware and software interlock ensures a high level of production safety. Example 3

[0056] Reference Figure 5 and Figure 6 This is the third embodiment of the present invention, which provides a roll-to-roll double-sided synchronous exposure device for precision metal strips. This device belongs to the conventional hardware carrier of the execution method and the carrying system.

[0057] Specifically, it includes: The transmission support unit 100 includes a base 101. An unwinding mechanism 102 and a winding mechanism 103 are respectively provided at both ends of the base 101. Tension guide rollers 104 are distributed between the unwinding mechanism 102 and the winding mechanism 103. The follow-up exposure unit 200 includes a drive mechanism 201 disposed in the middle section of the base 101. A main frame 202 is slidably disposed at the top of the drive mechanism 201. An exposure machine 203 is symmetrically disposed inside the main frame 202. An ultraviolet exposure light source 204 is disposed at the top of the exposure machine 203. A porous static pressure air flotation array 205 is disposed at the bottom of the exposure machine 203. The sensing and detection unit 300 includes a contact tension sensor 301 movably mounted on the tension guide roller group 104; an infrared thermal imager 302 suspended on the feed side of the base 101 via a bracket; an alignment camera 303 fixedly mounted on the follower main frame 202; and an overlay detection camera 304 fixed on the discharge side of the base 101 via a frame.

[0058] The unwinding mechanism 102 and the winding mechanism 103 are driven by external servo motors, which, together with the tension guide roller group 104, adjust the continuous horizontal transmission of the precision metal strip, thereby driving the strip through each station to obtain different processing treatments. The infrared thermal imager 302 and the tension sensor 301 are uniformly arranged on the feeding side in order to capture the original cold temperature field and initial tension before the strip is heated and deformed.

[0059] After the system calculation of the device is completed, the drive mechanism 201 starts to drive the main frame 202 at its top to give it the same running speed as the tape, thereby creating a relatively static macroscopic follow-up window and transmitting the information to the system for processing.

[0060] After entering the relatively static macroscopic follow-up window, two sets of porous static pressure air flotation arrays 205, arranged symmetrically upside down, synchronously construct a gas-supported membrane, non-contactly suspending and clamping the roll at the center. The alignment camera 303 directly locks onto the target offset, and the system controls the multi-layered plate-like stacked mechanical structure hidden inside the exposure machine 203 to perform relative translation and rotation, completing the microscopic correction of the mask posture. At the moment the fine-tuning and alignment are completed, the system triggers the ultraviolet exposure light source 204 to irradiate the mask. The light generated by the ultraviolet exposure light source 204 passes sequentially through the light-transmitting areas of the fine-tuned exposure machine 203 and the porous static pressure air flotation array 205, accurately imprinting latent images on both sides of the metal roll.

[0061] The linear sliding mechanism constructed by the drive mechanism 201 and the main frame 202 allows the massive exposure assembly to cover the dynamic compensation area simply by performing a reciprocating translational motion along the tape transport axis. This eliminates the need for frequent shutdowns during exposure, which would cause significant mechanical impact and tension fluctuations, as is required in traditional stepper equipment. This greatly simplifies the mechanical structure and control logic, ensuring that the double-sided exposure beam is always stably projected while achieving high-speed, high-precision dynamic closed-loop double-sided synchronous exposure.

[0062] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A roll-to-roll double-sided synchronous exposure method for precision metal strips, characterized in that, Includes the following steps: S1. A non-contact double-sided clamping method is used to hold the precision metal strip coated with photosensitive material through a gas pressure field, and the precision metal strip is driven to be continuously transported along a preset path. S2. Before the precision metal strip is transferred into the exposure station, the real-time tension parameters and surface temperature distribution parameters of the precision metal strip are collected simultaneously. S3. Combine the real-time tension parameters and the surface temperature distribution parameters to perform deformation calculation and obtain the micro-deformation compensation amount of the precision metal strip in the exposure station. S4. Simultaneously acquire the alignment target images of the front and back surfaces of the precision metal roll and the reference target images of the mask plates placed on both sides of the precision metal roll using the dual-sided optical imaging components. S5. Combining the micro-deformation compensation amount and the positional deviation between the alignment target image and the reference target image, calculate the multi-degree-of-freedom spatial pose adjustment command. S6. According to the multi-degree-of-freedom spatial pose adjustment command, drive the mask to move synchronously along the transmission direction of the precision metal strip, and perform double-sided synchronous exposure within a relatively static follow-up period.

2. The roll-to-roll double-sided synchronous exposure method for precision metal strips according to claim 1, characterized in that, The process of non-contact double-sided clamping of a precision metal strip coated with photosensitive material using a gas pressure field, as described in step S1, includes: A clean gas medium of equal pressure is synchronously sprayed onto the upper and lower surfaces of the precision metal strip to construct a gas support film of equal thickness on both sides of the precision metal strip, thereby constraining the normal displacement of the precision metal strip in the direction perpendicular to the transmission direction.

3. The roll-to-roll double-sided synchronous exposure method for precision metal strips according to claim 1, characterized in that, The process of synchronously acquiring the real-time tension parameters and surface temperature distribution parameters of the precision metal strip in step S2 includes: The dynamic tensile force data along the axial direction of the precision metal strip is continuously acquired using a contact-type tension sensing component, and the periodic jitter interference amplitude caused by the transmission power source is filtered out during data acquisition; simultaneously, the thermal radiation signal on the surface of the precision metal strip is scanned using an infrared thermal imaging component to construct a two-dimensional temperature gradient matrix that reflects the superposition of interference between the residual temperature of the previous process and the ambient airflow.

4. The roll-to-roll double-sided synchronous exposure method for precision metal strips according to claim 1, characterized in that, The process of performing deformation calculation and obtaining the micro-deformation compensation amount of the precision metal strip within the exposure station as described in step S3 includes: Based on the real-time tension parameters and the elastic modulus of the precision metal strip, the axial mechanical tensile deformation value of the precision metal strip is calculated using the following mechanical formula. : in, The real-time tension parameter is... The effective transmission segment length of the exposure station is [length]. The elastic modulus of the precision metal strip is given by [reference needed]. The cross-sectional area of ​​the precision metal strip is given; based on the surface temperature distribution parameters and the thermal expansion coefficient of the precision metal strip, the thermodynamic expansion deformation value is calculated using the following thermodynamic formula. : in, The coefficient of thermal expansion of the precision metal strip is given. The change in surface temperature distribution parameters relative to a preset reference temperature; the mechanical tensile deformation value. With the aforementioned thermodynamic expansion deformation value Spatial vector superposition is performed to generate the microscopic deformation compensation amount.

5. The roll-to-roll double-sided synchronous exposure method for precision metal strips according to claim 1, characterized in that, The process of synchronously acquiring images in step S4 includes: A polarized coaxial light source is used to emit an illumination beam toward the precision metal roll and the mask; the sub-pixel edge extraction algorithm is used to perform feature fitting on the acquired image to extract the true geometric center coordinates of the alignment target and the reference target.

6. The roll-to-roll double-sided synchronous exposure method for precision metal strips according to claim 1, characterized in that, The process of solving the multi-degree-of-freedom spatial pose adjustment command in step S5 includes: Lens distortion correction and incomplete feature repair are performed on the acquired target image and the reference target image to extract the true geometric center deviation. The micro-deformation compensation is injected into the true geometric center deviation as a feedforward offset to generate the multi-degree-of-freedom spatial pose adjustment command containing the expected deformation compensation.

7. The roll-to-roll double-sided synchronous exposure method for precision metal strips according to claim 1, characterized in that, Step S6, which describes driving the photomask to move synchronously along the transport direction of the precision metal strip and performing double-sided synchronous exposure during a relatively static follow-up period, includes: Based on the real-time transmission speed parameters of the precision metal strip, the translation drive component carrying the mask is controlled to accelerate in the same direction along the transmission direction; when the acceleration reaches the same level as the real-time transmission speed parameters, a relatively stationary follow-up window is established; within the follow-up window, according to the multi-degree-of-freedom spatial pose adjustment command, the multi-axis micro-motion component is triggered to perform the six-degree-of-freedom synchronous correction of the mask on the upper and lower sides, including planar translation, planar rotation, and spatial pitch attitude adjustment; the illumination radiation intensity of the exposure light source is adjusted synchronously to maintain the cumulative exposure dose per unit area received by the surface of the precision metal strip at a constant value.

8. The roll-to-roll double-sided synchronous exposure method for precision metal strips according to claim 7, characterized in that, After performing double-sided simultaneous exposure as described in step S6, the following is also included: After completing the double-sided synchronous exposure, the overlay accuracy of the exposed patterns on both sides of the precision metal strip is checked to obtain overlay deviation data; random jump data in the overlay deviation data is removed by a filtering algorithm to extract system drift data. Using the system drift data combined with the transmission path delay compensation coefficient, the following iterative correction algorithm is employed to calculate the basic weighting coefficients for the micro-deformation compensation amount. Make corrections and adjustments: in, This serves as the base weighting coefficient for the next exposure cycle after the update. This is the base weighting coefficient for the current exposure cycle. The transmission path delay compensation coefficient is... This refers to the system drift data.

9. A roll-to-roll double-sided synchronous exposure system for precision metal strips, characterized in that, The system is equipped with a computing device adapted to implement the roll-to-roll double-sided synchronous exposure method for precision metal strips as described in any one of claims 1 to 8.

10. A roll-to-roll double-sided synchronous exposure apparatus for precision metal strips, characterized in that, The apparatus is used to perform the method of any one of claims 1 to 8, and serves as the exposure execution carrier of the system of claim 9, specifically comprising: The transmission support unit (100) includes a base (101), and an unwinding mechanism (102) and a winding mechanism (103) are respectively provided at both ends of the base (101). Tension guide rollers (104) are distributed between the unwinding mechanism (102) and the winding mechanism (103). The follow-up exposure unit (200) includes a drive mechanism (201) disposed in the middle section of the base (101), a main frame (202) is slidably disposed at the top of the drive mechanism (201), an exposure machine (203) is symmetrically disposed inside the main frame (202), an ultraviolet exposure light source (204) is disposed at the top of the exposure machine (203), and a porous static pressure air flotation array (205) is disposed at the bottom of the exposure machine (203). The sensing and detection unit (300) includes a tension sensor (301) disposed on one side of the tension guide roller group (104); an infrared thermal imager (302) suspended on the upper bracket of the tension sensor (301); an alignment camera (303) fixedly installed on the follow-up main frame (202); and an overlay detection camera (304) fixed to the discharge side of the base (101) by the frame.

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