An automated screen printing device and method

Abstract

The application discloses an automatic silk-screen printing plate coating device and a method thereof, and belongs to the technical field of silk-screen printing. The automatic silk-screen printing plate coating device comprises a main body frame, a vertical guide rail is arranged on the main body frame, a coating head assembly is movably connected to the vertical guide rail, the coating head assembly comprises a lifting driving seat connected with a sliding block of the vertical guide rail, a scraper body is fixedly connected to the front end face of the lifting driving seat, a segmented flexible scraper is installed on the working blade edge of the scraper body, and the segmented flexible scraper is composed of a plurality of side-by-side arranged scraper segments, and a micro-pressure adjusting array is arranged on the scraper body. The application can continuously collect, calculate and adjust in the coating stroke, so that the final wet film thickness distribution of the whole screen printing plate can approach the set target value.

Description

Technical Field

[0001] This invention relates to the field of screen printing, specifically to an automated screen printing stencil coating device and method. Background Technology

[0002] Traditional automated screen printing stencil coating equipment typically employs an integrated squeegee and fixed coating parameters, such as constant coating speed and squeegee pressure. When dealing with stencils of varying mesh counts and tensions, or with photosensitive emulsions exhibiting slight viscosity differences between batches, this one-size-fits-all open-loop control strategy struggles to guarantee absolute uniformity in coating thickness. To avoid subsequent exposure and development defects caused by uneven coating, operators often need to rely heavily on experience for trial-and-error parameter adjustments or employ multiple coating processes to level the surface. This not only severely impacts stencil-making efficiency but also makes the yield highly dependent on the operator's individual skill, hindering stable, high-quality, standardized production.

[0003] The information disclosed in the background section above is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide an automated screen printing plate coating device and method to solve the problems mentioned in the background art.

[0005] The technical solution of the present invention includes:

[0006] The main frame is equipped with vertical guide rails.

[0007] A coating head assembly, movably connected to the vertical guide rail, the coating head assembly comprising:

[0008] A lifting drive seat, wherein the lifting drive seat is connected to the slider of the vertical guide rail;

[0009] The scraper body is fixedly connected to the front end face of the lifting drive seat;

[0010] The segmented flexible scraper is installed on the working blade of the scraper body, and the segmented flexible scraper is composed of multiple scraper segments arranged side by side.

[0011] A micro-pressure regulating array is installed at the rear of the scraper body and corresponds one-to-one with the scraper sections, used to apply independent normal pressure to the scraper sections;

[0012] A linear array profile sensor is fixedly installed on the scraper body, and its laser emission line is parallel to the working edge of the segmented flexible scraper, used to collect wet film thickness profile data after coating.

[0013] A controller, electrically connected to the linear array profile sensor and the micro-pressure adjustment array, is used to control the micro-pressure adjustment array to adjust the normal pressure applied to each of the scraper segments based on the wet film thickness profile data.

[0014] Preferably, a servo motor is installed inside the lifting drive seat. The output shaft of the servo motor drives an active synchronous pulley. The active synchronous pulley meshes with a synchronous belt that is vertically fixed to the main frame, and is used to drive the coating head assembly to move up and down along the vertical guide rail.

[0015] Preferably, each of the scraper segments is mounted on the working edge of the scraper body via an elastic connector, the elastic connector being used to provide preload in the normal direction and allow the scraper segment to produce minute displacement.

[0016] Preferably, the micro-pressure regulating array is composed of multiple micro piezoelectric ceramic actuators, each of which extends and retracts independently to convert its displacement into normal pressure on the corresponding scraper segment via a force-transmitting push rod.

[0017] An automated screen printing stencil coating method, comprising:

[0018] During the coating stroke of the coating head assembly, the linear array contour sensor is controlled to continuously acquire the wet film contour of the screen surface to generate real-time thickness contour data.

[0019] The data calculated from the difference between the real-time thickness profile data and the preset target thickness value is defined as the thickness deviation sequence;

[0020] The control commands generated based on the thickness deviation sequence and corresponding one-to-one with each of the scraper segments are defined as the pressure adjustment command sequence;

[0021] The controller receives the real-time thickness profile data and generates the thickness deviation sequence;

[0022] Based on the thickness deviation sequence, the controller independently generates and sends the pressure adjustment command sequence for the micro-pressure adjustment array;

[0023] The pressure adjustment command sequence is used to drive the micro-pressure adjustment array to adjust the normal pressure applied to the screen surface by each of the scraper segments, so that the thickness of the subsequently coated wet film approaches the target thickness value.

[0024] Preferably, the step of the controller generating the pressure adjustment command sequence based on the thickness deviation sequence includes:

[0025] The thickness deviation value at each position in the thickness deviation sequence is multiplied by a preset proportional gain coefficient to obtain the corresponding pressure adjustment amount in the pressure adjustment command sequence.

[0026] Preferably, the pressure adjustment command is used for:

[0027] When the thickness deviation value is positive, the micro-pressure adjustment array is instructed to reduce the corresponding normal pressure;

[0028] When the thickness deviation value is negative, the micro-pressure adjustment array is instructed to increase the corresponding normal pressure.

[0029] Preferably, the controller is further configured to:

[0030] Obtain the absolute vertical position of the coating head assembly corresponding to the number of pulses output by the servo motor encoder;

[0031] The absolute vertical position is correlated with the real-time thickness profile data to construct a complete wet film thickness distribution map.

[0032] This invention provides an automated screen printing stencil coating apparatus and method, which, compared with the prior art, has the following improvements and advantages:

[0033] 1. Because the device measures the wet film thickness in real time through a linear array contour sensor and the controller commands a micro-pressure adjustment array to apply independent normal pressure to each section of the segmented flexible squeegee for immediate adjustment, this solution can actively adapt to changes in working conditions such as uneven screen tension or fluctuations in the viscosity of the photosensitive emulsion. This fundamentally improves the consistency of the coating thickness, making the final wet film thickness distribution of the entire screen approach the set target value. Unlike traditional equipment that uses fixed parameters, this solution can actively adapt to changes in working conditions such as uneven screen tension or fluctuations in the viscosity of the photosensitive emulsion. By continuously collecting, calculating, and adjusting data during the coating process, the final wet film thickness distribution of the entire screen can approach the set target value.

[0034] 2. The controller calculates the required pressure adjustment by multiplying the thickness deviation value by a preset proportional gain coefficient. This defines how much pressure change is needed to compensate for a unit thickness deviation, ensuring the local accuracy of the pressure adjustment. The device drives an active synchronous pulley via a servo motor, which meshes with a synchronous belt vertically fixed to the main frame, thereby driving the coating head assembly to move up and down along the vertical guide rail. The controller can calculate the absolute vertical position of the coating head assembly in real time by reading the pulse signal output by the servo motor encoder, providing a positioning basis for accurately associating the wet film thickness data with the specific position on the screen. Attached Figure Description

[0035] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0036] Figure 1 This is a schematic diagram of the overall structure of the device;

[0037] Figure 2 This is a schematic diagram of the controller's connection structure;

[0038] Figure 3 This is a partially enlarged structural schematic diagram of the main frame;

[0039] Figure 4 This is a schematic diagram of the scraper section and its connection structure;

[0040] Figure 5 This is a schematic diagram of the process flow of the method of the present invention.

[0041] In the diagram: 100, main frame; 110, vertical guide rail; 200, coating head assembly; 210, lifting drive seat; 220, scraper body; 230, segmented flexible scraper; 231, scraper segment; 240, micro-pressure adjustment array; 250, linear array contour sensor; 300, controller. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0043] Example 1

[0044] Please see Figure 1-4 This invention provides an automated screen printing plate coating device, comprising:

[0045] The main frame 100 is provided with a vertical guide rail 110.

[0046] Coating head assembly 200, movably connected to vertical guide rail 110, includes:

[0047] The lifting drive base 210 is connected to the slider of the vertical guide rail 110.

[0048] The scraper body 220 is fixedly connected to the front end face of the lifting drive seat 210;

[0049] The segmented flexible scraper 230 is installed on the working blade of the scraper body 220, and the segmented flexible scraper 230 is composed of multiple scraper segments 231 arranged side by side.

[0050] The micro-pressure regulating array 240 is installed behind the scraper body 220 and corresponds one-to-one with the scraper section 231. It is used to apply independent normal pressure to the scraper section 231.

[0051] Linear array profile sensor 250 is fixedly installed on scraper body 220, and its laser emission line is parallel to the working edge of segmented flexible scraper 230, used to collect wet film thickness profile data after coating.

[0052] The controller 300 is electrically connected to the linear array profile sensor 250 and the micro pressure adjustment array 240, and is used to control the micro pressure adjustment array 240 to adjust the normal pressure applied to each scraper segment 231 based on the wet film thickness profile data.

[0053] In the screen printing plate-making process, equipment with fixed coating parameters is difficult to cope with variables such as uneven screen tension or fluctuations in photosensitive emulsion viscosity, resulting in uneven coating thickness and affecting product qualification rate. This automated screen printing plate coating device addresses this problem through a combination of structure and control. The coating head assembly 200 of this device moves on the vertical guide rail 110 of the main frame 100. Its core is that the linear array contour sensor 250 acquires wet film thickness contour data in real time during the coating stroke. The controller 300 receives this data and compares it with a preset target value to calculate the thickness deviation. The controller 300 instructs the micro-pressure adjustment array 240 to apply independent normal pressure to each squeegee segment 231 of the segmented flexible squeegee 230 for adjustment. This approach enables the coating process to proactively adapt to changes in working conditions, improving the consistency of coating thickness from the root by instantly correcting local coating pressure. Among them, the linear array profile sensor 250, as a non-contact measurement unit, can be a Keyence LJ-V series laser displacement sensor; the controller 300, as the core of data processing and command transmission, can be a Siemens S7-1200 series programmable logic controller 300.

[0054] The closed-loop control model of this device aims to dynamically correct local pressure during the coating process through real-time feedback to cope with external disturbances such as uneven screen tension or emulsion viscosity fluctuations, ensuring a consistent final coating thickness distribution. The core of this model is the feedback control loop. Its logical structure includes: an input end, where real-time wet film thickness data is provided by a linear array profile sensor 250; a comparator, where the controller 300 compares the real-time data with a preset target value to calculate the deviation; a controller 300, which generates adjustment commands based on the deviation; an actuator, where a micro-pressure adjustment array 240 performs pressure adjustment; and an output end, where the new wet film thickness generated during the coating process is collected again by the sensor, forming a new input. This model characterizes the physical causal relationship between the normal pressure applied by the squeegee and the amount of photosensitive emulsion passing through the screen during the coating process. Increasing the pressure increases the emulsion throughput, leading to a thicker coating; decreasing the pressure decreases the emulsion throughput, resulting in a thinner coating. The model utilizes this relationship to achieve direct control of the local wet film thickness by precisely adjusting the normal pressure applied to each independent squeegee segment 231.

[0055] A servo motor is installed inside the lifting drive seat 210. The output shaft of the servo motor drives the active synchronous wheel, which meshes with the synchronous belt that is vertically fixed to the main frame 100, and is used to drive the coating head assembly 200 to move up and down along the vertical guide rail 110.

[0056] In this embodiment, the lifting drive seat 210 has a servo motor installed inside, which provides precisely measurable rotational motion. The output shaft of the servo motor is connected to an active synchronous pulley, which meshes with a synchronous belt that is tensioned and vertically fixed to the main frame 100. When the servo motor rotates, its rotational motion is stably converted into linear lifting motion of the coating head assembly 200 along the vertical guide rail 110 through the synchronous belt drive. The purpose of this structure is to establish a precise position feedback mechanism. By reading the pulse signal output by the servo motor encoder and combining it with mechanical parameters such as the circumference of the active synchronous pulley, the controller 300 can calculate the absolute position of the coating head assembly 200 in the vertical direction in real time, providing a positioning basis for the subsequent precise correlation between the wet film thickness data and the specific position on the screen.

[0057] Each scraper section 231 is mounted on the working edge of the scraper body 220 via an elastic connector. The elastic connector is used to provide preload in the normal direction and allow the scraper section 231 to make small displacements.

[0058] This flexible connector can be constructed in various ways, such as by a set of small precision springs or flexible hinges. Its core function is to provide a basic preload while allowing the scraper segments to produce controlled micro-displacements in the normal direction. This design ensures that all scraper segments can adhere to the screen with a uniform reference pressure when there is no adjustment command, providing a stable reference for subsequent fine-tuning.

[0059] Each scraper segment 231 is connected to the working edge of the scraper body 220 via an elastic connector. This connection is not rigidly fixed; its function is to provide each scraper segment 231 with a basic, uniform initial preload, ensuring that a basic coating pressure is maintained without adjustment commands. Simultaneously, this connection allows each scraper segment 231 to generate a small, controlled displacement in the normal direction perpendicular to the screen surface. This displacement is a prerequisite for the effective pressure adjustment by the subsequent micro-pressure adjustment array 240. When the actuator of the micro-pressure adjustment array 240 actuates, the resulting small pushing displacement acts on the scraper segment 231, changing the deformation of the elastic connector and thus converting the displacement into an increase or decrease in the normal pressure applied to the screen. There are no specific limitations on the structure of the elastic connector capable of achieving this function; for example, it can be a flexible hinge structure or an assembly composed of a set of small precision springs.

[0060] The initial preload here serves to provide a stable and reliable reference for subsequent fine-tuning pressure. It ensures that all scraper segments 231 adhere tightly to the screen surface with a uniform reference pressure even when no adjustment force is applied to the micro-pressure adjustment array 240. This avoids coating interruptions or uneven initial coating caused by gaps or looseness between the scraper segments 231 and the screen. Using this reference as the zero point, subsequent fine-tuning commands, whether positive (increasing pressure) or negative (decreasing pressure), can be executed effectively and predictably.

[0061] The micro-pressure regulating array 240 consists of multiple micro piezoelectric ceramic actuators. Each micro piezoelectric ceramic actuator extends and retracts independently to convert its displacement into normal pressure on the corresponding scraper section 231 via a force-transmitting push rod. This actuator is a component of the micro-pressure regulating array 240.

[0062] Each piezoelectric ceramic actuator in the array corresponds one-to-one with a scraper segment 231 and acts directly on the back of the scraper segment through a force transmission rod. The controller 300 applies a voltage signal to a specific actuator to generate a precise micron-level telescopic displacement. This displacement is converted into a normal thrust on the scraper segment through the force transmission rod, thereby precisely adjusting the local coating pressure and realizing the precise conversion of electrical signal to local pressure.

[0063] The micro-pressure regulating array 240 in this embodiment is constructed as a row of parallel micro piezoelectric ceramic actuators. Piezoelectric ceramic actuators are chosen because they have the characteristics of fast response speed and high displacement accuracy. Each piezoelectric ceramic actuator in the array corresponds one-to-one with a scraper segment 231 in the segmented flexible scraper 230 and can be independently controlled by the controller 300. During operation, the controller 300 applies a voltage signal to a specific piezoelectric ceramic actuator, which then generates a precise, micron-level extension and retraction displacement. This displacement is transmitted directly to the back of the corresponding scraper segment 231 through a force transmission rod, converting it into a normal thrust or pull force on the scraper segment 231, thereby changing the local coating pressure applied by the scraper segment 231 to the screen surface, realizing the precise conversion from electrical signal to micro-displacement and then to local pressure.

[0064] Example 2

[0065] Please see Figure 5 An automated screen printing plate coating method, comprising:

[0066] During the coating stroke of the coating head assembly 200, the control linear array profile sensor 250 continuously acquires the wet film profile on the screen surface to generate real-time thickness profile data.

[0067] The data calculated from the difference between real-time thickness profile data and a preset target thickness value is defined as the thickness deviation sequence;

[0068] The control commands generated based on the thickness deviation sequence and corresponding one-to-one with each scraper segment 231 are defined as the pressure adjustment command sequence;

[0069] The controller 300 receives real-time thickness profile data and generates a thickness deviation sequence;

[0070] Based on the thickness deviation sequence, the controller 300 independently generates and sends a pressure adjustment command sequence to the micro-pressure adjustment array 240;

[0071] The pressure adjustment command sequence is used to drive the micro-pressure adjustment array 240 to adjust the normal pressure applied to the screen surface by each scraper segment 231, so that the thickness of the subsequently coated wet film approaches the target thickness value.

[0072] The automated screen printing stencil coating method is as follows: During the coating stroke of the coating head assembly 200 rising along the vertical guide rail 110, the linear array contour sensor 250 follows its movement and continuously scans the surface of the wet film that has just been coated, generating a continuous real-time thickness contour data stream; after receiving this data stream, the controller 300 compares it point by point with the preset target thickness value in the system, and the calculated difference values ​​constitute a thickness deviation sequence; this sequence reflects the coating thickness at different positions in the width direction of the stencil. Based on this thickness deviation sequence, the controller 300 then independently calculates and generates a pressure adjustment command for each scraper segment 231, and all commands are combined into a pressure adjustment command sequence. This command sequence is sent to the micro-pressure adjustment array 240, which drives its corresponding actuator to adjust the normal pressure of each scraper segment 231. Since data acquisition, calculation and pressure adjustment are performed continuously and at high speed, the controller 300 can continuously apply correction commands to the micro-pressure adjustment array 240 according to the real-time measured wet film thickness deviation, so that the coating head can dynamically adjust the local pressure throughout the entire stroke, thereby making the final wet film thickness distribution of the entire screen approach the set target thickness value.

[0073] Preset target thickness value In the screen printing plate-making process, the ideal wet film thickness is set by the operator in the controller 300 based on the characteristics of the photosensitive emulsion, the mesh count of the screen, and the precision requirements of the printed material. This serves as a reference point for closed-loop control. This value is usually input manually and is the benchmark for all subsequent thickness deviation calculations and pressure adjustments. The controller 300 compares the real-time acquired thickness data with this target value, calculates the thickness deviation sequence, and uses this deviation as the logical trigger for adjusting the normal pressure of each scraper segment 231.

[0074] The steps by which the controller 300 generates a pressure adjustment command sequence based on the thickness deviation sequence include:

[0075] Multiply the thickness deviation value at each position in the thickness deviation sequence by a preset proportional gain coefficient to obtain the corresponding pressure adjustment amount in the pressure adjustment command sequence.

[0076] The control method described in this invention is mainly a proportional control algorithm. In order to further improve the stability and response speed of the system, integral and derivative control terms can also be integrated in practical applications to form a complete PID controller. The integral term can eliminate the long-term static thickness deviation, while the derivative term can predict the thickness change trend and make adjustments in advance to cope with dynamic working conditions.

[0077] In this embodiment, when the controller 300 generates a pressure adjustment command sequence based on the thickness deviation sequence, the core calculation step is as follows: the controller 300 extracts the thickness deviation value corresponding to the position of each scraper segment 231 in the thickness deviation sequence, and multiplies this deviation value by a proportional gain coefficient preset in the control system. This proportional gain coefficient is pre-calibrated and stored based on factors such as the rheological properties of the photosensitive emulsion and the mechanical properties of the scraper, defining how much pressure change is needed to compensate for a unit thickness deviation; the result of this multiplication operation is the pressure adjustment amount corresponding to that scraper segment 231 in the pressure adjustment command sequence; this calculation process is performed independently for each scraper segment 231, ensuring the local accuracy of the pressure adjustment. This calculation logic can also be expressed by the following relationship:

[0078]

[0079] in, The representative needs to address the issue of the first... The pressure adjustment amount applied to each scraper section 231; Represents the proportional gain coefficient; The linear array profile sensor 250 represents the first The wet film thickness value measured in real time at the corresponding position of each scraper segment 231; This represents the target wet film thickness value entered by the operator.

[0080] Determine the proportional gain coefficient There are no specific limitations on the method. For example, one calibration method could be: for a specific combination of screen printing plate and photosensitive emulsion, in test mode, the controller 300 applies a series of known, step-increasing pressure commands to the micro-pressure regulating array 240, and simultaneously uses the linear array profile sensor 250 to measure the actual change in wet film thickness in the corresponding area under these different pressures. By recording and analyzing the one-to-one correspondence between these input pressure command values ​​and the output thickness change, a proportional gain coefficient that reflects the relationship between the two can be calculated or fitted, and stored as a preset parameter in the controller 300 for use during normal production.

[0081] The input to this calculation process is real-time thickness profile data from the linear profile sensor 250, as well as preset target thickness values ​​and proportional gain coefficients stored in the controller 300. The logical steps include: Step 1: The controller 300 processes each data point in the real-time thickness profile data. Compared with the preset target thickness value By comparing the values, the thickness deviation at the corresponding positions can be calculated. Step 2: The controller 300 multiplies each thickness deviation value by a preset proportional gain coefficient. To obtain the pressure adjustment amount corresponding to the scraper section 231. Step 3: The pressure adjustment amounts of all scraper sections 231 are combined to form a pressure adjustment command sequence; the final output of this process is the pressure adjustment command sequence, which is then sent to the micro-pressure regulating array 240 to independently adjust the normal pressure of each scraper section 231.

[0082] Pressure adjustment commands are used for:

[0083] When the thickness deviation is positive, the micro-pressure adjustment array 240 is instructed to reduce the corresponding normal pressure;

[0084] When the thickness deviation value is negative, the micro-pressure adjustment array 240 is instructed to increase the corresponding normal pressure.

[0085] In this embodiment, the pressure adjustment command has a clear adjustment logic direction. When the calculated thickness deviation value is positive, it indicates that the actual coating thickness at that location exceeds the target value, i.e., the coating is too thick. At this time, the generated pressure adjustment command will instruct the corresponding actuator in the micro-pressure adjustment array 240 to reduce its output, thereby reducing the normal pressure applied to the scraper section 231, so that the subsequent flow rate of photosensitive emulsion through this area is reduced. Conversely, when the thickness deviation value is negative, it indicates that the coating is too thin. The pressure adjustment command will instruct the actuator to increase its output to increase the normal pressure and increase the amount of photosensitive emulsion coated in this area, thereby correcting the thickness deviation.

[0086] The physical principle behind this adjustment is that the normal pressure applied to the scraper section 231 directly affects the interaction between the scraper blade and the flexible wire mesh. When the normal pressure increases, the pressure exerted by the scraper on the wire mesh increases, causing the wire mesh to undergo more significant elastic deformation in that local area. This makes it easier for the photosensitive emulsion to pass through the mesh openings, thereby increasing the emulsion throughput per unit area and forming a thicker coating. Conversely, when the normal pressure decreases, the elastic deformation of the wire mesh weakens, and the emulsion throughput through the mesh openings also decreases accordingly, resulting in a thinner coating. Therefore, by precisely controlling the normal pressure applied to each independent scraper section 231, direct control of the local wet film thickness can be achieved.

[0087] Controller 300 is also used for:

[0088] Obtain the absolute vertical position of the coating head assembly 200 corresponding to the number of pulses output by the servo motor encoder;

[0089] The absolute vertical position is correlated with real-time thickness profile data to construct a complete wet film thickness distribution map;

[0090] To ensure the accuracy of the adjustment, the data acquisition of the linear contour sensor 250, the calculation of the controller 300, and the adjustment of the micro-pressure adjustment array 240 need to be carried out at high speed and in real time. The controller 300 not only needs to process the lateral wet film contour data, but also needs to acquire the vertical position information provided by the servo motor encoder. By associating each lateral contour data with the corresponding vertical position data, the controller can construct a two-dimensional wet film thickness distribution map covering the entire screen printing working area. This map can not only be used for quality traceability, but also provide valuable data for subsequent process analysis and parameter optimization.

[0091] In this embodiment, the controller 300 performs data integration and mapping functions simultaneously with the coating method. When the controller 300 collects real-time lateral thickness profile data through the linear array profile sensor 250, it simultaneously obtains the pulse count from the encoder of the servo motor that drives the coating head assembly 200 to rise and fall. Using preset mechanical parameters, such as the circumference of the synchronous wheel and the reduction ratio, the controller 300 converts the pulse count into the absolute vertical position of the coating head assembly 200 in real time. The controller 300 associates each lateral thickness profile data with the corresponding absolute vertical position data. By continuously repeating this process throughout the entire coating stroke, all data points with position information are integrated, thereby constructing a complete two-dimensional wet film thickness distribution map covering the entire screen working area in the controller 300's memory or external storage. This map can be used for quality traceability and process analysis.

[0092] 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.

Claims

1. An automated screen printing stencil coating device, characterized in that, include: The main frame (100) is provided with a vertical guide rail (110). A coating head assembly (200), movably connected to the vertical guide rail (110), the coating head assembly (200) comprising: A lifting drive seat (210) is connected to the slider of the vertical guide rail (110); The scraper body (220) is fixedly connected to the front end face of the lifting drive seat (210); The segmented flexible scraper (230) is installed on the working edge of the scraper body (220), and the segmented flexible scraper (230) is composed of multiple scraper segments (231) arranged side by side. A micro-pressure regulating array (240) is installed behind the scraper body (220) and corresponds one-to-one with the scraper section (231). It is used to apply independent normal pressure to the scraper section (231). The micro-pressure regulating array (240) is composed of multiple micro piezoelectric ceramic actuators. Each micro piezoelectric ceramic actuator extends and retracts independently to convert its displacement into the normal pressure on the corresponding scraper section (231) through the force transmission rod. Linear array contour sensor (250) is fixedly installed on the scraper body (220), and its laser emission line is parallel to the working edge of the segmented flexible scraper (230) for collecting wet film thickness contour data after coating. A controller (300) electrically connected to the linear array profile sensor (250) and the micro pressure adjustment array (240) is used to control the micro pressure adjustment array (240) to adjust the normal pressure applied to each of the scraper segments (231) based on the wet film thickness profile data. During the coating stroke of the coating head assembly (200), the linear array contour sensor (250) is controlled to continuously acquire the wet film contour of the screen surface to generate real-time thickness contour data. The controller (300) is used to: obtain the absolute vertical position of the coating head assembly (200) corresponding to the number of pulses output by the servo motor encoder, and associate the absolute vertical position with the real-time thickness profile data to construct a complete wet film thickness distribution map.

2. The automated screen printing plate coating device according to claim 1, characterized in that, A servo motor is installed inside the lifting drive seat (210). The output shaft of the servo motor drives the active synchronous wheel. The active synchronous wheel meshes with the synchronous belt that is vertically fixed to the main frame (100) to drive the coating head assembly (200) to move up and down along the vertical guide rail (110).

3. The automated screen printing plate coating device according to claim 1, characterized in that, Each of the scraper segments (231) is mounted on the working edge of the scraper body (220) by means of an elastic connector, which is used to provide preload in the normal direction and allow the scraper segments (231) to produce small displacements.

4. An automated screen printing stencil coating method, applied to the automated screen printing stencil coating apparatus as described in claim 1, characterized in that, include: The data calculated from the difference between the real-time thickness profile data and the preset target thickness value is defined as the thickness deviation sequence; Define the control commands generated based on the thickness deviation sequence and corresponding one-to-one with each of the scraper segments (231) as the pressure adjustment command sequence; The controller (300) receives the real-time thickness profile data and generates the thickness deviation sequence; The controller (300) independently generates and sends the pressure adjustment command sequence for the micro-pressure adjustment array (240) based on the thickness deviation sequence; The pressure adjustment command sequence is used to drive the micro pressure adjustment array (240) to adjust the normal pressure applied to the screen surface by each of the scraper segments (231) so that the thickness of the subsequently coated wet film approaches the target thickness value.

5. The automated screen printing plate coating method according to claim 4, characterized in that, The step of the controller (300) generating the pressure adjustment command sequence based on the thickness deviation sequence includes: The thickness deviation value at each position in the thickness deviation sequence is multiplied by a preset proportional gain coefficient to obtain the corresponding pressure adjustment amount in the pressure adjustment command sequence.

6. The automated screen printing plate coating method according to claim 5, characterized in that, The pressure adjustment command is used for: When the thickness deviation value is positive, the micro-pressure adjustment array (240) is instructed to reduce the corresponding normal pressure; When the thickness deviation value is negative, the micro pressure adjustment array (240) is instructed to increase the corresponding normal pressure.

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