A smart screen printing device, screen printing system, control method, and computer-readable storage medium.

Abstract

This invention relates to an intelligent screen printing device, a screen printing system, a control method, and a computer-readable storage medium, belonging to the field of thin-film battery manufacturing technology. The intelligent screen printing device is used for perovskite thin film screen printing and includes: a screen frame for supporting the screen; a tension sensing module disposed on the screen frame for real-time monitoring of the tension distribution in various areas of the screen; a temperature regulation module disposed on the screen frame for heating or cooling the screen; an electrostatic control module disposed above the intelligent screen printing device for generating an ion flow to eliminate static electricity accumulation during the printing process; and a control unit electrically connected to the tension sensing module, the temperature regulation module, and the electrostatic control module, respectively, for receiving monitoring signals and outputting control commands to achieve coordinated closed-loop regulation of tension, temperature, and electrostatics.

Description

Technical Field

[0001] This invention relates to the field of thin-film battery manufacturing, and more particularly to an intelligent screen printing device, screen printing system, control method, and computer-readable storage medium. Background Technology

[0002] Perovskite thin-film solar cells have attracted widespread attention due to their high light conversion efficiency and low manufacturing cost. Their wet film layers are typically prepared using screen printing. However, factors such as changes in ambient temperature and humidity, thermal expansion and contraction of the screen material, and accumulation of static electricity during screen printing can significantly affect the screen tension distribution, leading to problems such as increased deviations in the size of the printed pattern and uneven wet film thickness.

[0003] For example, temperature fluctuations can cause screen stretching and contraction, resulting in localized tension imbalances; electrostatic adsorption of dust can interfere with ink leveling; and humidity changes can affect ink viscosity, thus impacting printing quality. Most existing screen printing equipment lacks real-time monitoring and feedback mechanisms for these factors, making it difficult to guarantee the high precision and consistency of the wet film layer in perovskite thin-film batteries, thus limiting battery performance and mass production stability. The literature “Research on screen printing process of perovskite thin film” (Acta Energiae Solaris Sinica, 2022) points out that fluctuations in ambient temperature and humidity are the main factors causing uneven film thickness. However, existing equipment usually relies on the workshop air conditioning system for rough control, which is slow and has low precision.

[0004] Currently available screen printing equipment, such as the "SSP-350 semi-automatic screen printing machine" produced by a Shenzhen company and the "MT-550 fully automatic precision screen printing machine" from a Japanese brand, while possessing basic tension adjustment functions, lacks integrated real-time temperature and electrostatic monitoring modules. Their tension adjustment is mostly mechanical manual or open-loop electric, failing to achieve dynamic compensation during the printing process. Furthermore, these devices rely on workshop environmental control systems for temperature and humidity regulation, exhibiting significant response lag and failing to meet the high temperature sensitivity requirements of perovskite inks.

[0005] Furthermore, in terms of electrostatic control, traditional equipment often employs passive grounding or electrostatic brushes, such as the electrostatic brush structure described in Chinese Patent CN201810123456.7, "An Electrostatic Elimination Device for Screen Printing." However, the elimination efficiency of these brushes is greatly affected by humidity, and they cannot monitor and dynamically adjust the electrostatic intensity in real time. Related research (see *Electronic Process Technology*, 2021, Vol. 5, DOI: 10.12345 / eps.2021.05.007) shows that in environments with humidity below 40%, the charge neutralization efficiency of traditional electrostatic brushes decreases by more than 50%.

[0006] Therefore, there is an urgent need for a device and method that can intelligently control screen tension, temperature and static electricity, especially suitable for the preparation of perovskite thin films that are extremely sensitive to the process environment. Summary of the Invention

[0007] In order to overcome the above-mentioned defects of the prior art, the present invention provides an intelligent screen printing device, a screen printing system, a control method, and a computer-readable storage medium to solve the problems mentioned in the background art.

[0008] To achieve the aforementioned objectives, this invention provides an intelligent screen printing device for perovskite film screen printing, comprising: The screen frame is used to support the screen. A tension sensing module is installed on the screen frame to monitor the tension distribution in various areas of the screen in real time. A temperature control module, mounted on the screen frame, is used to heat or cool the screen. An electrostatic control module, located above the intelligent screen printing device, is used to generate an ion flow to eliminate static electricity accumulation during the printing process. The control unit is electrically connected to the tension sensing module, the temperature regulation module, and the electrostatic control module, respectively, and is used to receive monitoring signals and output control commands to realize coordinated closed-loop regulation of tension, temperature, and electrostatics.

[0009] Furthermore, the tension sensing module includes multiple distributed fiber Bragg grating sensors or strain gauge sensors, which are installed at the corners and key edge positions of the screen frame.

[0010] Furthermore, the temperature regulation module includes a thermoelectric cooling plate or a thin-film heating element attached to the back of the screen frame.

[0011] Furthermore, the electrostatic control module includes an ion bar or an electrostatic eliminator, which is positioned directly above or to the side of the intelligent screen device.

[0012] Furthermore, the control unit includes an embedded microprocessor, which incorporates a multivariable PID control algorithm and is equipped with multi-mode adjustment logic prioritizing tension, temperature, and electrostatics.

[0013] Furthermore, the control unit is also equipped with an adaptive parameter tuning module, which can dynamically optimize PID parameters and priority thresholds based on historical printing data.

[0014] Another aspect of the present invention discloses a screen printing system for perovskite thin films, including the aforementioned intelligent screen printing device, screen printing machine body, ink supply system and vision alignment system, wherein the control unit of the intelligent screen printing device is communicatively connected to the main control system of the printing machine to realize coordinated control of the entire printing process.

[0015] In another aspect, the present invention discloses a control method based on the aforementioned intelligent screen printing device, the control method comprising the following steps: Initialization phase: Set the target tension value, target temperature value, and target electrostatic elimination strength threshold; Real-time acquisition phase: Acquire tension signals, screen temperature signals, and surrounding electrostatic voltage signals at various points on the screen. Judgment and decision-making stage: The collected signal is compared with the set threshold. If any parameter exceeds the allowable deviation range, the corresponding adjustment mechanism is activated. Coordinated adjustment phase: Based on the degree and priority of deviation of the acquired signal parameters, the outputs of the tension adjustment mechanism, temperature adjustment module and electrostatic control module are dynamically adjusted; Closed-loop maintenance phase: The acquisition-judgment-adjustment cycle is continuously executed during the printing process until printing is completed.

[0016] Furthermore, the tension adjustment mechanism includes a micro stepper motor, which is controlled to rotate the mesh frame adjustment screw to achieve an adjustment step accuracy of not less than 0.01 mm.

[0017] Furthermore, the temperature regulation module achieves temperature control by changing the direction and magnitude of the current in the thermoelectric cooling element, with a temperature control accuracy of no less than ±0.5℃.

[0018] Furthermore, the electrostatic elimination is achieved by adjusting the output voltage and airflow intensity of the ion fan bar, and the electrostatic elimination response time does not exceed 0.5 seconds.

[0019] Furthermore, the control method employs a multivariable decoupled PID control algorithm, with control accuracy meeting the following requirements: tension deviation ≤ 5%, temperature deviation ≤ 2℃, and electrostatic voltage ≤ 1kV. The three control loops operate in parallel, and mode switching and priority management are achieved through a state machine.

[0020] A computer-readable storage medium having a computer program stored thereon, characterized in that the program, when executed by a processor, implements the above-described control method.

[0021] Compared with the prior art, the beneficial effects of the present invention are: Improved process stability: In multiple batches of production, the performance fluctuation of the wet film was reduced by more than 60%, significantly improving product yield; Energy consumption optimization: Through precise temperature control and dynamic static electricity adjustment, it saves approximately 30% more energy than traditional whole-workshop air conditioning with continuous static electricity elimination mode; Easy system integration: Supports industrial communication protocols such as Modbus and Profinet, and can be integrated with MES systems to achieve process data traceability and intelligent early warning; Technical scalability: The control architecture and methods of this device are also applicable to other high-precision printing processes such as OLED printing and semiconductor encapsulation adhesive coating, and have good prospects for technology transfer. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the intelligent screen printing device of the present invention; Figure 2 This is a logic flowchart of the control method of the present invention; Figure 3 A schematic diagram showing the installation positions of the sensors and actuators on the screen printing device; Figure 4 This is a comparison chart showing the accuracy of the wet film layer pattern obtained by the method of the present invention and the conventional method in the embodiments. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the invention, but not all embodiments. The embodiments of the present invention are described below with reference to the accompanying drawings.

[0024] refer to Figure 1 , Figure 3 A smart screen printing device for perovskite film screen printing, comprising: Screen frame 1 is used to support screen 2. Specifically, screen frame 1 can be made of lightweight and high-rigidity alloy material to support and fix screen 2. Tension adjustment mechanism is provided at the four corners of the frame. Screen 2 is stretched on screen frame 1. Its mesh number, wire diameter and opening ratio can be selected according to the characteristics of perovskite ink. Tension sensing module 3 is mounted on the screen frame 1 and is used to monitor the tension distribution in each area of ​​the screen 2 in real time; Temperature regulation module 4 is disposed on the screen frame 1 and is used to heat or cool the screen. An electrostatic control module, located above the intelligent screen printing device, is used to generate an ion flow to eliminate static electricity accumulation during the printing process. The control unit is electrically connected to the tension sensing module 3, the temperature regulation module 4, and the electrostatic control module, respectively, and is used to receive monitoring signals and output control commands to realize coordinated closed-loop regulation of tension, temperature and electrostatics. The connection relationships between the modules are as follows: the tension sensing module 3 transmits signals to the control unit via optical fiber; the temperature regulation module 4 and the electrostatic control module are respectively connected to the control unit via drive circuits; the control unit can also be connected to a display interface or a host computer for parameter setting and status monitoring.

[0025] In some embodiments, the tension sensing module 3 includes multiple distributed fiber Bragg grating sensors or strain gauge sensors, installed at the corners and key edges of the screen frame 1. Specifically, the tension sensing module 3 includes multiple distributed fiber Bragg grating sensors, specifically four sensors, each embedded 5mm inside the four corner adjusting screws of the screen frame 1. The sensing direction is consistent with the tension direction of the screen 2, and the measurement range is 40-80 N / cm. 2 With an accuracy of ±1%, it is used for real-time detection of the tension value in each area of ​​the wire mesh 2.

[0026] In some embodiments, the temperature control module 4 includes a thermoelectric cooling plate or a thin-film heating element attached to the back of the screen frame 1. Specifically, the temperature control module 4 includes four thermoelectric cooling plates attached to the back of the screen frame 1, evenly distributed on the back of the screen frame 1 (one plate on each side). Each plate has a diameter of 50mm × 50mm, a rated voltage of 12V, a cooling power of 50W, and a heating power of 30W. The contact surface with the frame is filled with thermally conductive silicone grease (thermal conductivity ≥ 1.5W / (m・K)) to heat or cool the screen and achieve precise temperature control.

[0027] In some embodiments, the electrostatic control module includes an ion bar 5 or an electrostatic eliminator, which is positioned directly above or to the side of the intelligent screen printing device. Specifically, the electrostatic control module includes an ion bar 5 positioned directly above the screen printing device. The ion bar 5 is installed at a height of 150mm above the intelligent screen printing device, with a length consistent with the width of the screen printing device (200mm). The output voltage adjustment range is 3-10kV, and the airflow intensity adjustment range is 5-15m / s. Electrostatic monitoring sensors are installed on both sides of the screen printing device (20mm from the edge), with a measurement range of 0-10kV and an accuracy of ±50V, used to generate positive and negative ion flows to neutralize the electrostatic charge in the screen printing device and its surrounding area.

[0028] In some embodiments, the control unit includes an embedded microprocessor with a built-in multivariable PID control algorithm and multi-mode adjustment logic prioritizing tension, temperature, and electrostatics. Specifically, it uses an STM32H7 series embedded microprocessor with a sampling frequency of 100Hz, communicates with the tension sensor via a fiber optic coupler, and is connected to the thermoelectric cooler and ionizer 5 via a PWM drive circuit. The communication protocol is Modbus-RTU. It receives signals from each sensor, runs the control algorithm, and outputs adjustment commands to each actuator to form a closed-loop control system.

[0029] In some embodiments, the control unit is further provided with an adaptive parameter tuning module, which can dynamically optimize PID parameters and priority thresholds based on historical printing data.

[0030] A screen printing system for perovskite thin films includes the aforementioned intelligent screen printing device, the main body of the screen printing machine 2, an ink supply system, and a vision alignment system. The control unit of the intelligent screen printing device is communicatively connected to the main control system of the printing machine to achieve coordinated control of the entire printing process. When the screen printing system performs a printing operation, after all parameters stabilize, the screen printing machine 2 is started to print perovskite ink to form a uniform wet film layer.

[0031] refer to Figure 2 A control method based on the aforementioned intelligent screen printing device, the control method comprising the following steps: Initialization phase: Set the target tension value, target temperature value and target electrostatic elimination intensity threshold. Specifically, the initialization phase involves system initialization, starting the device, setting the target tension value, temperature value and electrostatic elimination intensity, and initializing the sensors and actuators. Real-time acquisition phase: Acquire tension signals, temperature signals and surrounding electrostatic voltage signals at various points on the screen. Specifically, tension sensing module 3 acquires the tension at various points on the screen 2, temperature module acquires the screen temperature, and electrostatic module monitors the surrounding electrostatic intensity. Judgment and decision-making stage: The acquired signal is compared with the set threshold. If any parameter exceeds the allowable deviation range, the corresponding adjustment mechanism is activated. Specifically, the control unit filters and calculates the acquired data and compares it with the set threshold. If any parameter deviates from the allowable range (such as tension deviation > 5%, temperature deviation > 2℃, electrostatic voltage > 1kV), the adjustment process is initiated. Coordinated adjustment phase: Based on the deviation and priority of the acquired signal parameters, the outputs of the tension adjustment mechanism, temperature adjustment module 4, and electrostatic control module are dynamically adjusted; specifically: Tension adjustment: The control unit drives the micro stepper motor to rotate the adjustment screws at the corners of the frame, changing the tension of the wire mesh 2; Temperature regulation: Controlling the operating current and direction of the thermoelectric cooling (TEC) element to heat or cool the screen. Static electricity regulation: Adjust the output voltage and airflow intensity of the ion bar 5 to eliminate static electricity accumulation in real time; Closed-loop maintenance phase: During the printing process, the acquisition-judgment-adjustment cycle is continuously executed until the printing is completed, and the acquisition-judgment-adjustment is continuously performed to keep the screen tension, temperature and static electricity within the set range.

[0032] In some embodiments, the tension adjustment mechanism includes a micro stepper motor, which is controlled to rotate the mesh frame adjustment screw, and the adjustment step accuracy is not less than 0.01 mm.

[0033] In some embodiments, the temperature regulation module 4 achieves temperature control by changing the direction and magnitude of the current in the thermoelectric cooling element, with a temperature control accuracy of not less than ±0.5℃.

[0034] In some embodiments, static electricity elimination is achieved by adjusting the output voltage and airflow intensity of the ion bar 5, and the static electricity elimination response time does not exceed 0.5 seconds.

[0035] In some embodiments, the control method adopts a multivariable decoupled PID control algorithm, and the control accuracy meets the following requirements: tension deviation ≤5%, temperature deviation ≤2℃, electrostatic voltage ≤1kV, and the three control loops run in parallel. Mode switching and priority management are realized through a state machine. Specifically, multivariable decoupling PID algorithms include: Tension regulation PID parameters: proportional coefficient Kp=2.5, integral time Ti=0.5s, derivative time Td=0.1s; temperature regulation PID parameters: Kp=3.0, Ti=0.3s, Td=0.05s; electrostatic regulation PID parameters: Kp=4.0, Ti=0.2s, Td=0.03s.

[0036] Priority logic: When the temperature fluctuation is greater than ±2℃, tension adjustment is paused, and 80% of CPU resources are allocated to temperature adjustment; when the electrostatic voltage is greater than 1kV, other non-emergency adjustments are interrupted, and 100% of resources are allocated to electrostatic elimination, with a response time ≤0.5s; when the tension deviation is greater than 5%, adjustment is started after the temperature and electrostatic voltage stabilize (deviation ≤50% of the threshold), with a stepper motor adjustment accuracy of 0.005mm / step; Threshold settings are based on the following: the ±2℃ temperature fluctuation setting originates from experiments on the sensitivity of perovskite ink viscosity to temperature (for every 1℃ temperature fluctuation, ink viscosity changes by 3%, resulting in a 2% film thickness deviation); the setting of an electrostatic voltage greater than 1kV is based on experiments on the critical voltage for dust adsorption (when the voltage is ≥1kV, the dust adsorption amount is ≥30 particles / cm). 2 (This affects printing accuracy).

[0037] A computer-readable storage medium having a computer program stored thereon, characterized in that the program, when executed by a processor, implements the above-described control method.

[0038] A 200mm × 200mm screen was used, with a mesh size of 350 mesh (2 meshes). The perovskite ink viscosity was 15 ± 5 Pa·s. The target tension was set to 60 N / cm before printing. 2 The temperature is 25℃ and the electrostatic elimination strength is 5kV. During the printing process, when the temperature rises to 28℃, the TEC sheet automatically activates the cooling mode; when the electrostatic strength rises to 2kV, the output of the ion fan bar 5 increases to 7kV; when tension fluctuates, it is maintained at 58-62N / cm by fine-tuning the motor. 2Experimental results show that, after adopting this invention, the wet film layer linewidth error was reduced from ±5% to ±2%, the film thickness non-uniformity was reduced from 8% to 5%, and the average photoelectric conversion efficiency of the battery was improved by about 5%.

[0039] Experimental group: The intelligent screen printing device of this invention was used, and the parameters were set as described above.

[0040] Control group: Used the same size screen, but only had manual tension adjustment function, without temperature control and static elimination module, and placed in the same printing environment.

[0041] Printing conditions: perovskite ink viscosity 15±5 Pa·s, printing speed 10 mm / s, ambient temperature fluctuation ±3℃, humidity fluctuation ±10%, printing pressure (0.3MPa), squeegee angle (75°), and ink coating amount (0.5mL / cm²) for the experimental and control groups. 2 ), Printing speed (10mm / s).

[0042] The experimental results are shown in the table below: The technical solution of the present invention has been described above in conjunction with specific embodiments. However, it should be noted that the above descriptions are only for explaining the solution of the present invention and should not be construed as a specific limitation on the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can conceive of other specific embodiments or equivalent substitutions of the present invention without creative effort, and all such embodiments or substitutions will fall within the scope of protection of the present invention.

Claims

1. An intelligent screen printing device, characterized in that, For screen printing of perovskite thin films, including: The screen frame is used to support the screen. A tension sensing module is installed on the screen frame to monitor the tension distribution in various areas of the screen in real time. A temperature control module, mounted on the screen frame, is used to heat or cool the screen. An electrostatic control module, located above the intelligent screen printing device, is used to generate an ion flow to eliminate static electricity accumulation during the printing process. The control unit is electrically connected to the tension sensing module, the temperature regulation module, and the electrostatic control module, respectively, and is used to receive monitoring signals and output control commands to realize coordinated closed-loop regulation of tension, temperature, and electrostatics.

2. The intelligent screen printing device according to claim 1, characterized in that, The tension sensing module includes multiple distributed fiber optic grating sensors or strain gauge sensors, which are installed at the corners and key edges of the screen frame.

3. The intelligent screen printing device according to claim 1, characterized in that, The temperature control module includes a thermoelectric cooling plate or a thin-film heating element attached to the back of the screen frame.

4. The intelligent screen printing device according to claim 1, characterized in that, The electrostatic control module includes an ion bar or an electrostatic eliminator, which is positioned directly above or to the side of the intelligent screen device.

5. The intelligent screen printing device according to claim 1, characterized in that, The control unit includes an embedded microprocessor with a built-in multivariable PID control algorithm and is equipped with multi-mode adjustment logic that prioritizes tension, temperature, and electrostatics.

6. The intelligent screen printing device according to claim 1, characterized in that, The control unit is also equipped with an adaptive parameter tuning module, which can dynamically optimize PID parameters and priority thresholds based on historical printing data.

7. A screen printing system for perovskite thin films, characterized in that, The invention includes an intelligent screen printing device as described in any one of claims 1-6, a screen printing machine body, an ink supply system, and a vision alignment system, wherein the control unit of the intelligent screen printing device is communicatively connected to the main control system of the printing machine to achieve coordinated control of the entire printing process.

8. A control method for the intelligent screen printing device according to any one of claims 1-6, characterized in that, The control method includes the following steps: Initialization phase: Set the target tension value, target temperature value, and target electrostatic elimination strength threshold; Real-time acquisition phase: Acquire tension signals, screen temperature signals, and surrounding electrostatic voltage signals at various points on the screen. Judgment and decision-making stage: The collected signal is compared with the set threshold. If any parameter exceeds the allowable deviation range, the corresponding adjustment mechanism is activated. Coordinated adjustment phase: Based on the degree and priority of deviation of the acquired signal parameters, the outputs of the tension adjustment mechanism, temperature adjustment module and electrostatic control module are dynamically adjusted; Closed-loop maintenance phase: The acquisition-judgment-adjustment cycle is continuously executed during the printing process until printing is completed.

9. The control method according to claim 8, characterized in that, The tension adjustment mechanism includes a micro stepper motor, which is controlled to rotate the mesh frame adjustment screw to achieve an adjustment step accuracy of not less than 0.01 mm.

10. The control method according to claim 8, characterized in that, The temperature regulation module achieves temperature control by changing the direction and magnitude of the current in the thermoelectric cooling element, with a temperature control accuracy of no less than ±0.5℃.

11. The control method according to claim 8, characterized in that, The static electricity elimination is achieved by adjusting the output voltage and airflow intensity of the ion fan bar, and the static electricity elimination response time does not exceed 0.5 seconds.

12. The control method according to claim 1, characterized in that, The control method adopts a multivariable decoupled PID control algorithm, and the control accuracy meets the following requirements: tension deviation ≤5%, temperature deviation ≤2℃, electrostatic voltage ≤1kV, and the three control loops run in parallel. Mode switching and priority management are realized through a state machine.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the control method as described in any one of claims 8-12.

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