Flexible circuit board photosensitive wet film processing method and device thereof

Abstract

The present application relates to a kind of flexible circuit board photosensitive wet film processing method and device, it is related to flexible circuit board manufacturing technical field, method includes: the printing material is sequentially conveyed to multiple printing stations, and the printing plate roll is made with partial circuit pattern in each station;First pattern is printed in first station and mark point is printed at its end position;Subsequent station detects previous mark point by sensor, and next pattern is printed from mark point and spliced after the phase of printing plate roll is adjusted and accurately positioned;Repeat this process until all patterns are spliced complete.The device includes rack, conveying mechanism, multiple printing units and controller, and each printing unit contains printing plate roll, impression roller, sensor and drive module.The present application realizes the direct forming of long size circuit pattern by multi-station splicing printing, gets rid of the length limit of film, and simplifies production process.

Description

Technical Field

[0001] This invention relates to the field of flexible circuit board manufacturing technology, and specifically to a method and apparatus for processing a photosensitive wet film for flexible circuit boards. Background Technology

[0002] Flexible printed circuit boards (FPCs) are characterized by high wiring density, light weight, thinness, and good bendability, and are widely used in fields such as power battery connection systems for new energy vehicles. In the FPC manufacturing process, photosensitive wet film processing is a crucial step in forming circuit patterns or solder mask patterns.

[0003] Currently, photosensitive wet film processing typically employs coating methods such as roller coating, screen printing, or spraying. These methods essentially involve full-width coating of the flexible circuit board substrate (printing material). After coating, a series of complex processes are required, including pre-drying, film (negative) alignment, vacuum bonding, UV exposure, development, and post-curing, to complete the patterning of the wet film. This traditional process has a significant drawback: limited by the size of the film plate, the pattern length of the flexible circuit board products that can be processed is usually no more than 2000 mm, which cannot meet the market demand for longer flexible circuit board products (e.g., exceeding 3000 mm). Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and apparatus for processing photosensitive wet film on flexible circuit boards. This method can realize the direct printing of long-sized circuit patterns, get rid of the length limitation of film plates, and simplify the production process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for processing a photosensitive wet film on a flexible circuit board, characterized by comprising the following steps: Step S1: The printing material is conveyed to and passes through at least two printing stations arranged sequentially along its conveying direction. Each printing station is equipped with a printing plate roller, an impression roller, and a sensor. A flexographic printing plate is mounted on the surface of the printing plate roller, and a partial circuit pattern is formed on the flexographic printing plate. Step S2: At the first printing station, control the movement of the impression roller to make the printing material adhere to the printing plate roller, and use the printing plate roller to transfer liquid photosensitive ink onto the printing material to print the first version of the circuit pattern, and print the first mark point at the end position of the first version of the circuit pattern; then control the impression roller to retract, so that the printing material is removed from the printing plate roller. Step S3: Transfer the printing material to the next printing station. During the transfer process, solidify the first version of the circuit pattern printed at the previous station. Detect the position of the first mark point through the sensor at this station to ensure the relative position of the printing origin of the printing plate roller with the first mark point. Step S4: Control the movement of the impression roller. The impression roller pulls the printing material and finally makes the printing material adhere to the printing plate roller. At this time, the printing origin of the printing plate roller of the next printing station coincides with the first mark point. The second version of the circuit pattern, which is spliced ​​with the first version of the circuit pattern, is printed from the first mark point. The second mark point is printed at the end position of the second version of the circuit pattern. Step S5: Repeat steps S3 and S4 until all printing stations have completed the printing of the corresponding circuit pattern in sequence, and the circuit patterns of each plate are spliced ​​together by positioning through the marked points.

[0006] Preferably, the printing material is a flexible circuit board substrate, such as polyimide or polyester film.

[0007] Preferably, the liquid photosensitive ink is a photosensitive resist ink or a photosensitive solder resist ink.

[0008] Preferably, in steps S2 and S4, the movement and retraction of the impression roller are controlled by driving the impression roller to move through the drive module, so as to achieve the adhesion and separation of the printing material and the printing plate roller.

[0009] In a second aspect, the present invention provides a flexible circuit board photosensitive wet film processing apparatus for implementing any of the above methods, characterized in that it comprises: frame; A conveying mechanism, mounted on the frame, is used to convey printing material along a set direction; At least two printing units arranged sequentially along the conveying direction, each printing unit comprising: The printing plate roller is rotatably mounted on the frame, and its surface is used to mount a flexographic printing plate with a partial circuit pattern. An impression roller, disposed opposite to the printing plate roller, is used to press the printing material toward the printing plate roller; The sensor, located at the entrance side of the corresponding printing unit, is used to detect the marking points on the printing substrate; A drive module, mounted on the frame, is used to drive the impression roller to move so that it can fit or separate from the printing plate roller; The controller is electrically connected to each of the sensors, the drive mechanism of each of the printing plate rollers, and each of the drive modules. It is used to control the phase of the corresponding printing plate roller according to the mark point signal detected by the sensor (i.e., to realize mark tracking control) and to control the action timing of the drive module.

[0010] Preferably, the drive module is a cylinder or an electric motor.

[0011] Preferably, the system also includes a movable compensation roller and a connecting rod; the impression roller and the movable compensation roller are connected by the connecting rod, and the output end of the drive module is connected to the connecting rod to drive the connecting rod to move the impression roller and the movable compensation roller synchronously.

[0012] Preferably, a curing lamp is provided on the frame and above the impression roller and the moving compensation roller for curing the printed circuit patterns.

[0013] Preferably, an anilox roller is mounted on the frame and located behind the printing plate roller, a doctor blade is mounted on the frame and located on the outer side of the anilox roller, an ink roller is mounted on the frame and located behind the anilox roller, and an ink trough is mounted on the frame and located below the ink roller. The anilox roller, doctor blade, ink roller, and ink trough together constitute a system for supplying ink to the printing plate roller.

[0014] The preset markers in this invention have standard shapes (such as crosses, circles, or lines). While detecting their positions, the sensor simultaneously acquires the image clarity and integrity. If a marker is blurry, incomplete, or abnormally positioned, the system can immediately issue a warning, indicating potential ink problems, improper roller pressure, or mechanical malfunctions at that station, thus enabling real-time detection of printing defects.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention employs a flexographic printing method, directly decomposing a complete circuit pattern into multiple parts. These parts are then printed and assembled sequentially at multiple printing stations, ultimately forming a complete circuit pattern on the substrate. The combination of marker points with elements such as "multi-station flexographic printing," "impression roller / compensation roller linkage mechanism," and "liquid photosensitive ink" overcomes the limitations of traditional film plates on the length of product graphics, enabling the production of flexible circuit boards of varying lengths (especially those exceeding 3000mm).

[0016] 2. This invention combines the patterning and coating processes of the photosensitive wet film into one, eliminating the complex steps of film alignment and vacuum bonding in traditional processes, significantly simplifying the process flow and improving production efficiency.

[0017] 3. By setting marker points and sensors for tracking control, and combining the linkage mechanism of the impression roller and the moving compensation roller, the positional accuracy of multi-plate graphic splicing and the stability of the printing process are ensured. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0019] Figure 2 This is a partial structural diagram of the device of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure for setting the marker points in this invention.

[0021] In the diagram: 1. Printing plate roller; 2. Printing substrate; 3. Impression roller; 4. Sensor; 5. Motion compensation roller; 6. Connecting rod; 7. Frame; 8. Conveying mechanism; 9. Drive module; 10. Anilox roller; 11. Ink roller; 12. Doctor blade; 13. Ink trough; 14. Curing lamp; 15. Printing origin. Detailed Implementation

[0022] 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 only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figures 1 to 3 As shown, the present invention provides a flexible circuit board photosensitive wet film processing device, including a frame 7, a conveying mechanism 8, four printing units and a controller (not shown in the figure).

[0024] The conveying mechanism 8 is mounted on the frame 7 and uses roller drive for transmission along the horizontal direction. Figure 3 The flexible circuit board substrate (such as polyimide film) is conveyed as printing material 2 from right to left.

[0025] Four printing units are arranged sequentially on the frame 7 along the conveying direction of the printing substrate 2. Each printing unit has the same structure, mainly including a printing plate roller 1, an impression roller 3, a sensor 4, a drive module 9, and an ink supply system.

[0026] The printing plate roller 1 is rotatably mounted on the frame 7, and flexographic printing plates are mounted on its surface. Each flexographic printing plate is engraved or plated with a portion of the required complete circuit pattern (i.e., the plate separation pattern). The impression roller 3 is located behind the printing plate roller 1, opposite to it. A sensor 4 (such as a photoelectric sensor or a vision sensor) is mounted on the frame 7 at the entrance side of this printing unit to detect the markings printed on the substrate 2 by the previous station.

[0027] The drive module 9 is used to control the movement of the impression roller 3. In this embodiment, the drive module 9 is preferably a cylinder. To ensure the stability of the tension of the printing material 2 during the pressing and separating process, the device is also equipped with a moving compensation roller 5 and a connecting rod 6. The impression roller 3 and the moving compensation roller 5 are connected together by a rigid connecting rod 6, and the output end of the drive module 9 is connected to the connecting rod 6. When the drive module 9 is activated, it synchronously drives the impression roller 3 and the moving compensation roller 5 to move together towards or away from the printing plate roller 1 through the connecting rod 6, thereby achieving reliable adhesion and smooth separation of the printing material 2 from the printing plate roller 1.

[0028] The ink supply system supplies liquid photosensitive ink (such as photosensitive resist ink) to the flexographic plate on the printing plate roller 1. This system typically includes an ink trough 13, an ink roller 11 immersed in the ink trough 13, an anilox roller 10, and a doctor blade 12. The ink roller 11 transfers ink to the anilox roller 10, and the doctor blade 12 removes excess ink from the surface of the anilox roller 10, leaving a measured amount of ink in the cells of the anilox roller 10. The anilox roller 10 then evenly transfers the ink to the raised graphic portion of the flexographic plate on the printing plate roller 1.

[0029] A curing lamp 14 (such as a UV LED lamp) is installed on the frame 7 above the impression roller 3 and the moving compensation roller 5 to cure the photosensitive ink pattern that has just been printed on the substrate 2 and set it.

[0030] The controller is electrically connected to the sensor 4 of each printing unit, the servo motor (for phase adjustment) that drives the printing plate roller 1, the drive module 9, and the conveying mechanism 8, and is responsible for coordinating the operation of the entire device.

[0031] Based on the above-described apparatus, the specific implementation process of the flexible circuit board photosensitive wet film processing method of the present invention is as follows: Preparation stage: The flexible circuit board substrate is loaded onto the conveying mechanism 8. The corresponding flexographic printing plate of the printing plate roller 1 of each printing unit has been installed, and liquid photosensitive ink has been added to the ink trough 13. All impression rollers 3 are in the retracted (disengaged) state under the drive of the drive module 9.

[0032] Step S1: Start the device, and the conveying mechanism 8 will convey the printing material 2 to the first printing station (first station).

[0033] Step S2: When the printing material 2 arrives at the first station and the controller receives the printing start signal detected by the sensor 4 at that station, it controls the drive module 9 of the first station to move, pushing the connecting rod 6 to make the impression roller 3 and the moving compensation roller 5 move upward synchronously. The impression roller 3 presses the printing material 2 onto the flexographic plate of the printing plate roller 1. The printing plate roller 1 rotates, transferring the first part of the line pattern and a "first mark point" located at the end of the part of the pattern onto the printing material 2. After printing is completed, the drive module 9 drives the impression roller 3 to retract, the printing material 2 detaches from the printing plate roller 1, and moves downstream under the traction of the conveying mechanism 8. During the movement, the curing lamp 14 above illuminates and cures the newly printed pattern and mark point.

[0034] Step S3: The printing material 2 is conveyed to the second printing station. During the conveying process, the graphic printed at the first station is solidified. When the printing material 2 enters the second station, the sensor 4 (second sensor) at this station detects the position of the "first mark point" on the printing material 2 and feeds the signal back to the controller. Based on this signal, the controller performs "tracking" control by adjusting the rotation phase of the printing plate roller 1 at the second station to ensure that its printing origin 15 (i.e., the starting point of the second part of the graphic on the flexographic plate) and the "first mark point" on the printing material 2 achieve a preset relative positional relationship (the goal is to make the two coincide in space).

[0035] Step S4: After the marking is completed, the controller controls the drive module 9 of the second station to move, causing the impression roller 3 of that station to move backward and press against the printing material 2. At this time, due to the marking control, the printing origin 15 of the printing plate roller 1 of the second station is exactly aligned with the "first mark point" on the printing material 2. The printing plate roller 1 starts to rotate, printing the second part of the circuit pattern from the "first mark point" to seamlessly connect it with the first part of the pattern, and printing the "second mark point" at the end position of the second part of the pattern. After printing is completed, the impression roller 3 retracts, and the pattern is cured.

[0036] Step S5: Repeat steps S3 and S4 above until the last printing station completes the printing of its corresponding part of the circuit pattern. All parts of the pattern are spliced ​​together through precise marking point positioning, ultimately forming a complete long-size circuit pattern on the printing substrate 2. After completing the printing of one pattern, the device can be reset to begin the printing cycle of the next pattern.

[0037] In summary, this invention, through innovative multi-station flexographic printing technology, successfully solves the problem of patterned production of photosensitive wet films for long flexible circuit boards, and has significant practical value and promising prospects for promotion.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for processing a photosensitive wet film on a flexible circuit board, characterized in that, Includes the following steps: Step S1: The printing material (2) is conveyed to and passes through at least two printing stations arranged in sequence along its conveying direction. Each printing station is equipped with a printing plate roller (1), an impression roller (3), and a sensor (4). The printing plate roller (1) is mounted with a flexographic printing plate, and a portion of the circuit pattern is formed on the flexographic printing plate. Step S2: At the first printing station, control the movement of the impression roller (3) to make the printing material (2) adhere to the printing plate roller (1), and use the printing plate roller (1) to transfer liquid photosensitive ink onto the printing material (2) to print the first version of the circuit pattern, and print the first mark point at the end position of the first version of the circuit pattern; then control the impression roller (3) to retract, so that the printing material (2) is removed from the printing plate roller (1). Step S3: Transfer the printing material (2) to the next printing station. During the transfer process, the first version of the circuit pattern printed at the previous station is solidified. The position of the first mark point is detected by the sensor (4) at this station to ensure the relative position of the printing origin (15) of the printing plate roller (1) and the first mark point. Step S4: Control the action of the printing roller (3), the printing roller (3) pulls the printing material (2), and finally makes the printing material (2) adhere to the printing plate roller (1). At this time, the printing origin (15) of the printing plate roller (1) of the next printing station coincides with the first mark point (horizontal direction). The second version of the circuit pattern spliced ​​with the first version of the circuit pattern is printed from the first mark point, and the second mark point is printed at the end position of the second version of the circuit pattern. Step S5: Repeat steps S3 and S4 until all printing stations have completed the printing of the corresponding circuit pattern in sequence, and the circuit patterns of each plate are spliced ​​together by positioning through the marked points.

2. The method for processing a photosensitive wet film on a flexible circuit board according to claim 1, characterized in that, The printing material (2) is a flexible circuit board substrate.

3. The method for processing a photosensitive wet film on a flexible circuit board according to claim 1, characterized in that, The liquid photosensitive ink is a photosensitive resist ink or a photosensitive solder resist ink.

4. The method for processing a photosensitive wet film on a flexible circuit board according to claim 1, characterized in that, In steps S2 and S4, the movement and retraction of the impression roller (3) are controlled by driving the impression roller (3) to move through the drive module (9) so as to achieve the bonding and separation of the printing material (2) and the printing plate roller (1).

5. A flexible circuit board photosensitive wet film processing apparatus for implementing the method of any one of claims 1-4, characterized in that, Rack (7); The conveying mechanism (8) is used to convey the printing material (2) along a set direction. At least two printing units arranged sequentially along the conveying direction, each printing unit comprising: A printing plate roller (1) has a surface for mounting a flexographic printing plate with a partial circuit pattern. An impression roller (3) is arranged opposite to the printing plate roller (1) and is used to press the printing material (2) onto the printing plate roller (1). Sensor (4) is set on the inlet side of the corresponding printing unit to detect the marking points on the printing material (2); The driving module (9) is used to drive the impression roller (3) to move so that it is in contact with or separate from the printing plate roller (1); The controller is electrically connected to each of the sensors (4), the drive mechanism of each of the printing rollers (1) and the drive module (9), and is used to control the phase of the corresponding printing roller (1) according to the marker signal detected by the sensor (4) and control the timing of the operation of the drive module (9).

6. The flexible circuit board photosensitive wet film processing apparatus according to claim 5, characterized in that, The drive module (9) is a cylinder or a motor.

7. The flexible circuit board photosensitive wet film processing apparatus according to claim 5, characterized in that, It also includes a movable compensation roller (5) and a connecting rod (6); the impression roller (3) and the movable compensation roller (5) are connected by the connecting rod (6), and the output end of the drive module (9) is connected to the connecting rod (6) to drive the connecting rod (6) to move the impression roller (3) and the movable compensation roller (5) synchronously.

8. The flexible circuit board photosensitive wet film processing apparatus according to claim 7, characterized in that, A curing lamp is provided on the support (7) and above the impression roller (3) and the moving compensation roller (5).

9. The flexible circuit board photosensitive wet film processing apparatus according to claim 7, characterized in that, The bracket (7) is provided with an anilox roller (10) on the rear side of the printing roller (1), the bracket (7) is provided with a scraper on the outer side of the anilox roller (10), the bracket (7) is provided with an ink roller (11) on the rear side of the anilox roller (10), and the bracket (7) is provided with an ink trough on the lower side of the ink roller (11).

Images