A high-precision screen printing plate detection device

Abstract

This invention provides a high-precision screen printing stencil inspection device for use in the field of screen printing stencil inspection. Through the cooperation between the spraying mechanism and the developing plate, the spraying mechanism moves horizontally along the upper surface of the screen printing stencil, spraying out electromagnetic powder and performing a vertical downward displacement. Some of the electromagnetic powder moves downward through the printing section and adheres to the surface of the developing plate. Because the electromagnetic powder affects the electric field of the energized ITO conductive layer, it generates an electrical signal, which is recorded by the control unit. The image processing module then generates a corresponding image and compares it with the designed printing pattern of the screen printing stencil to inspect the printing effect. This invention does not require contact with the conductive paste, and the inspection process does not contaminate the screen printing stencil, reducing the need for cleaning procedures before shipment and effectively lowering production costs. Furthermore, the image comparison is performed by a computer, resulting in high inspection accuracy and efficiency. It has market potential and is suitable for widespread application.

Description

Technical Field

[0001] This application relates to the field of screen printing stencil inspection, and in particular to a high-precision screen printing stencil inspection device. Background Technology

[0002] In the solar panel manufacturing industry, screen printing stencil fabrication is a crucial step in the pre-production process. The printing process begins with placing the silicon wafer onto the printing table. A very fine screen printing stencil is fixed to a frame and placed above the silicon wafer. The screen seals off the area except for the grid lines, allowing the conductive paste to pass through. Because the front side requires finer metal wires, the mesh of the screen used for front printing is typically much finer than that used for back printing. An appropriate amount of paste is placed on the screen, and a squeegee is used to spread the paste, ensuring it fills the mesh evenly. As the squeegee moves, it forces the paste through the mesh onto the silicon wafer.

[0003] However, due to factors such as personnel, equipment, environment, and materials, defects in screen printing stencils are almost unavoidable. To avoid losses caused by these defects, almost all screen printing stencil manufacturers employ stencil inspectors. Although manual visual inspection can indeed detect some defects, customers have increasingly higher requirements for the conductive printing quality of solar panels. Even when inspectors are fully focused, small defects may not be effectively detected. The eye and physical fatigue and mental relaxation caused by long-term inspections make it even more difficult to guarantee the inspection results. Missed defects in screen printing stencils often lead to batch rework of solar panels, customer complaints, and claims, causing significant losses and troubles for screen printing stencil manufacturers.

[0004] Meanwhile, the traditional inspection method involves applying conductive paste to the screen printing stencil and then printing, with the forming effect inspected manually. This process leaves conductive paste residue on the surface of the screen printing stencil, requiring a cleaning process when the stencil leaves the factory, which increases costs. To address these issues, we propose a high-precision screen printing stencil inspection device. Summary of the Invention

[0005] The purpose of this application is to design a non-contact screen printing stencil inspection device to avoid manual printing and subsequent visual inspection and cleaning procedures, thereby improving inspection efficiency and accuracy. Compared with the prior art, this application provides a high-precision screen printing stencil inspection device. The device is equipped with a spraying mechanism on the frame and a displacement mechanism on the frame for driving the spraying mechanism to move against the upper surface of the screen printing stencil. The spraying mechanism is used to spray electromagnetic powder vertically downwards. An electromagnet is fixed at the top of the spraying mechanism and is used to apply a vertical magnetic field to the electromagnetic powder.

[0006] The top of the frame is fixed with a display board, which includes an insulating layer. ITO conductive layers are provided on both the upper and lower sides of the insulating layer. The ITO conductive layers are ITO structures used for capacitive screens. Under the condition of being energized, the ITO conductive layers on the upper and lower sides form several equally spaced negative electric fields.

[0007] The screen printing stencil is positioned between the jetting mechanism and the developing plate. The frame also has a control unit with a built-in image processing module. The control unit is used to detect changes in the electric field on the ITO conductive layer and record the XY axis coordinate data of the changing electric field. The image processing module is used to generate an image based on the recorded XY axis coordinate data and compare it with the design printing pattern on the screen printing stencil.

[0008] Furthermore, the spraying mechanism incorporates a high-voltage discharge needle and a magnetic powder nozzle. The input end of the magnetic powder nozzle is connected to a magnetic powder feeding device. The high-voltage discharge needle generates an equal amount of negative charge alternately with the frequency of the power supply and attaches it to the magnetic powder sprayed by the magnetic powder nozzle.

[0009] Furthermore, the screen printing stencil includes a mesh body fixed within a frame, the mesh body having a shielding portion for blocking conductive paste and a printing portion for penetrating conductive paste, wherein the particle size of the electromagnetic powder is smaller than the mesh diameter of the printing portion.

[0010] Furthermore, a protective layer is provided on the top of the display panel, and the protective layer is a flexible protective layer.

[0011] Furthermore, when an electromagnet is energized, it generates a vertically downward magnetic field, and the electromagnetic powder tends to displace downwards under the influence of the electromagnet's magnetic field.

[0012] Furthermore, the repulsive force between the electromagnetic particles is greater than the magnetic attraction force between them.

[0013] Furthermore, a conveyor belt for transporting screen printing stencils is provided on one side of the frame, and a feeding mechanism is also provided on the frame. A feeding port corresponding to the feeding mechanism is provided on the top of the frame. The feeding mechanism is used to grab screen printing stencils from the feeding port for inspection.

[0014] Furthermore, the feeding mechanism includes a second Y-axis module fixed to the top of the frame, a second Z-axis module fixed to the output end of the second Y-axis module, and a pneumatic clamp fixed to the output end of the second Z-axis module.

[0015] Furthermore, the displacement mechanism includes a first Z-axis module fixed to the top of the frame, a first Y-axis module fixed to the output end of the first Z-axis module, and a lifting cylinder fixed to the output end of the first Y-axis module. There are two sets of lifting cylinders, one of which has its output end fixedly connected to the injection mechanism and the electromagnet.

[0016] Furthermore, a scraper is fixed to the output end of another set of lifting cylinders.

[0017] Compared to existing technologies, the advantages of this application are:

[0018] (1) This invention utilizes the interaction between the spraying mechanism and the display plate. Driven by the displacement mechanism, the spraying mechanism moves along the upper surface of the screen printing plate and sprays electromagnetic powder during the translation process. Under the action of the vertical magnetic field generated by the electromagnet, it moves vertically downward. Some of the electromagnetic powder is blocked by the shielding part and cannot move downward, while some of the electromagnetic powder moves downward through the printing part and adheres to the surface of the display plate. Since the electromagnetic powder affects the electric field of the energized ITO conductive layer, it generates an electrical signal, which is recorded by the control unit. The image processing module then produces a corresponding image and compares it with the design printing pattern of the screen printing plate to detect the printing effect of the screen printing plate. Compared with traditional detection methods, this invention does not require contact with the conductive paste and will not contaminate the screen printing plate during the detection process, reducing the cleaning process before leaving the factory and effectively reducing production costs. At the same time, the image comparison is performed by a computer. Compared with traditional manual visual inspection, its detection accuracy and efficiency are high, and it has market prospects and is suitable for promotion and application.

[0019] (2) The design of the flexible protective layer prevents the falling electromagnetic powder from rebounding, which can effectively improve the imaging accuracy of the display panel.

[0020] (3) By designing the strength of the charge repulsion and magnetic attraction between the electromagnetic powders, the sprayed magnetic powders are less likely to attract and stick together, which effectively improves the passability of the electromagnetic powders on the screen printing plate.

[0021] (4) Through the structural design of the scraper, after the screen printing plate held by the feeding mechanism is inspected, the scraper is driven by the displacement mechanism to perform a cleaning operation on the surface of the display plate, and cleans and recycles the magnetic powder remaining on the display plate, reducing the loss of magnetic powder and facilitating the next cycle of the display plate operation.

[0022] (5) Through the design of the feeding mechanism, the present invention can automatically realize the loading and unloading operation, realize the assembly line-style inspection operation, effectively improve the inspection efficiency and reduce the inspection cost. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the front structure of this application;

[0024] Figure 2 This is a side view of the structure of this application;

[0025] Figure 3 This is a schematic diagram of the feeding mechanism proposed in this application;

[0026] Figure 4 This is a schematic diagram of the displacement mechanism proposed in this application;

[0027] Figure 5 This is a cross-sectional structural schematic diagram of the displacement mechanism proposed in this application;

[0028] Figure 6 This is a schematic diagram of the displacement mechanism proposed in this application before displacement;

[0029] Figure 7 This is a schematic diagram of the displacement mechanism proposed in this application after displacement.

[0030] Figure 8 This is a schematic diagram of the trajectory of the magnetic powder as proposed in this application;

[0031] Figure 9 This is a schematic diagram illustrating the state in which the magnetic powder and the developing plate are engaged, as proposed in this application.

[0032] Figure 10 This is a schematic diagram of the injection mechanism proposed in this application.

[0033] Explanation of the labels in the diagram:

[0034] Frame 1, Feed port 11, Displacement mechanism 2, First Z-axis module 21, First Y-axis module 22, Lifting cylinder 23, Loading mechanism 3, Second Y-axis module 31, Second Z-axis module 32, Pneumatic clamp 33, Conveyor belt 4, Imaging board 5, Protective layer 51, Insulating layer 52, ITO conductive layer 53, Screen printing stencil 6, Screen body 61, Masking part 611, Printing part 612, Scraper 7, Spraying mechanism 8, Electromagnet 81, High-voltage discharge needle 82, Magnetic powder nozzle 83. Detailed Implementation

[0035] The embodiments will be described clearly and completely with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0036] Example 1:

[0037] This invention provides a high-precision screen printing stencil detection device. Please refer to [link / reference]. Figure 1-10 The device includes a frame 1, a spraying mechanism 8 on the frame 1, and a displacement mechanism 2 on the frame 1 for driving the spraying mechanism 8 to move in contact with the upper surface of the screen printing plate 6. The spraying mechanism 8 is used to spray electromagnetic powder vertically downwards. An electromagnet 81 is fixed on the top of the spraying mechanism 8. The electromagnet 81 is used to apply a vertical magnetic field to the electromagnetic powder.

[0038] The top of the frame 1 is fixed with a display board 5. The display board 5 includes an insulating layer 52. ITO conductive layers 53 are provided on both the upper and lower sides of the insulating layer 52. The ITO conductive layers 53 are ITO structures for capacitor screens. The ITO conductive layers 53 on the upper and lower sides form several equidistant negative electric fields under the condition of being energized.

[0039] The screen printing stencil 6 is set between the jetting mechanism 8 and the developing plate 5. The frame 1 is also equipped with a control unit. The control unit has a built-in image processing module. The control unit is used to detect the change of electric field on the ITO conductive layer 53 and record the XY axis coordinate data of the change electric field. The image processing module is used to generate an image through the recorded XY axis coordinate data and compare it with the design printing pattern of the screen printing stencil 6.

[0040] This invention utilizes the interaction between the spraying mechanism 8 and the developing plate 5. In actual use, the screen printing stencil 6 to be tested is fixedly placed on the developing plate 5. At this time, the ITO conductive layer 53 on the developing plate 5 is energized, forming several equidistantly arranged negative electric fields. Driven by the displacement mechanism 2, the spraying mechanism 8 is moved along the upper surface of the screen printing stencil 6, spraying out electromagnetic powder during the translation process. Under the action of the vertical magnetic field generated by the electromagnet 81, it performs a vertical downward displacement action. Some of the electromagnetic powder is blocked by the shielding part 611 and cannot move downward, while some electromagnetic powder moves downward through the printing part 612 and adheres to the developing plate. On the surface of the screen, the electromagnetic powder affects the electric field of the energized ITO conductive layer 53, thus generating an electrical signal. This signal is recorded by the control unit, and the image processing module generates a corresponding image, which is then compared with the designed printing pattern on the screen printing plate 6. This allows for the detection of the printing effect of the screen printing plate 6. Compared with traditional detection methods, this invention does not require contact with the conductive paste, and the detection process does not contaminate the screen printing plate 6, reducing the cleaning process before leaving the factory and effectively reducing production costs. Furthermore, the computer performs image comparison, which offers higher detection accuracy and efficiency compared to traditional manual visual inspection. This invention has market potential and is suitable for widespread application.

[0041] It should be noted that in this embodiment, the spraying mechanism 8 has a built-in high-voltage discharge needle 82 and a magnetic powder nozzle 83. The input end of the magnetic powder nozzle 83 is connected to a magnetic powder feeding device. The high-voltage discharge needle 82 generates an equal amount of negative charge alternately with the frequency of the power supply and attaches it to the magnetic powder sprayed by the magnetic powder nozzle 83. The screen printing plate 6 includes a mesh body 61 fixed in the frame. The mesh body 61 is provided with a shielding part 611 for blocking conductive paste and a printing part 612 for penetrating conductive paste. The particle size of the electromagnetic powder is smaller than the mesh diameter of the printing part 612.

[0042] The top of the display panel 5 is provided with a protective layer 51, which is a flexible protective layer.

[0043] The design of the flexible protective layer 51 prevents the falling electromagnetic powder from bouncing, effectively improving the imaging accuracy of the display panel 5.

[0044] When the electromagnet 81 is energized, it generates a vertically downward magnetic field. The electromagnetic powder tends to move downward under the influence of the magnetic field of the electromagnet 81, and the charge repulsion between the electromagnetic powders is greater than the magnetic attraction between them.

[0045] By designing the strength of the charge repulsion and magnetic attraction between the electromagnetic powder particles, the sprayed magnetic powder is less likely to attract and clump together, effectively improving the passability of the electromagnetic powder on the screen printing plate 6.

[0046] Example 2:

[0047] This invention provides a high-precision screen printing stencil detection device. Please refer to [link / reference]. Figure 1-10 Components that are the same as or corresponding to those in Embodiment 1 are referred to by the same reference numerals as those in Embodiment 1. For the sake of simplicity, only the differences from Embodiment 1 will be described below:

[0048] In this embodiment, a conveyor belt 4 for transporting the screen printing plate 6 is provided on one side of the frame 1, and a feeding mechanism 3 is also provided on the frame 1. A feeding port 11 corresponding to the feeding mechanism 3 is provided on the top of the frame 1. The feeding mechanism 3 is used to grab the screen printing plate 6 from the feeding port 11 for inspection.

[0049] The feeding mechanism 3 includes a second Y-axis module 31 fixed to the top of the frame 1. A second Z-axis module 32 is fixed to the output end of the second Y-axis module 31. A pneumatic clamp 33 is fixed to the output end of the second Z-axis module 32. The displacement mechanism 2 includes a first Z-axis module 21 fixed to the top of the frame 1. A first Y-axis module 22 is fixed to the output end of the first Z-axis module 21. A lifting cylinder 23 is fixed to the output end of the first Y-axis module 22. There are two sets of lifting cylinders 23. The output end of one set of lifting cylinders 23 is fixedly connected to the spraying mechanism 8 and the electromagnet 81. The output end of the other set of lifting cylinders 23 is fixed to the scraper 7.

[0050] Through the structural design of the scraper 7, after the screen printing plate 6 held by the feeding mechanism 3 has been inspected, it is put back into the conveyor belt 4 by the feeding mechanism 3. At this time, the scraper 7 moves down to contact the surface of the display plate 5 under the drive of the displacement mechanism 2. Driven by the first Y-axis module 22, it performs a cleaning operation on the surface of the display plate 5, cleaning and recycling the magnetic powder remaining on the display plate 5, reducing the loss of magnetic powder, and also facilitating the next cycle of the display plate 5.

[0051] Through the design of the feeding mechanism 3, in actual use, the pneumatic clamp 33 is moved to the feeding port 11 by the cooperation of the second Y-axis module 31 and the second Z-axis module 32. The open side of the pneumatic clamp 33 is used to clamp the frame side of the screen printing plate 6 conveyed on the conveyor belt 4. After the clamping action is performed, it is moved again to the bottom of the spraying mechanism 8 for image detection. This invention can automatically realize loading and unloading operations, realize assembly line-style detection operations, effectively improve detection efficiency and reduce detection costs.

[0052] The above description is only the best implementation method adopted in this application in combination with current practical needs, but the scope of protection of this application is not limited thereto.

Claims

1. A high-precision screen printing plate detection device, comprising a rack (1), characterized in that, The frame (1) is provided with a spraying mechanism (8), and the frame (1) is also provided with a displacement mechanism (2) for driving the spraying mechanism (8) to move against the upper surface of the screen printing plate (6). The spraying mechanism (8) is used to spray electromagnetic powder vertically downward. An electromagnet (81) is fixed on the top of the spraying mechanism (8). The electromagnet (81) is used to apply a vertical magnetic field to the electromagnetic powder. The top of the frame (1) is fixed with a display board (5). The display board (5) includes an insulating layer (52). ITO conductive layers (53) are provided on both the upper and lower sides of the insulating layer (52). The ITO conductive layer (53) is an ITO structure for a capacitive screen. The ITO conductive layers (53) on the upper and lower sides form several equidistant negative electric fields under the condition of being energized. The screen printing plate (6) is set between the jetting mechanism (8) and the developing plate (5). The frame (1) is also equipped with a control unit. The control unit has a built-in image processing module. The control unit is used to detect the change of electric field on the ITO conductive layer (53) and record the XY axis coordinate data of the change electric field. The image processing module is used to generate an image through the recorded XY axis coordinate data and compare it with the design printing pattern of the screen printing plate (6). The spraying mechanism (8) has a built-in high-voltage discharge needle (82) and a magnetic powder nozzle (83). The input end of the magnetic powder nozzle (83) is connected to a magnetic powder feeding device. The high-voltage discharge needle (82) generates an equal amount of negative charge alternately with the frequency of the power supply and attaches it to the magnetic powder sprayed by the magnetic powder nozzle (83). The charge repulsion between the electromagnetic powder particles is greater than the magnetic attraction between them.

2. The high-precision screen printing stencil detection device according to claim 1, characterized in that, The screen printing stencil (6) includes a mesh body (61) fixed in the frame. The mesh body (61) is provided with a shielding part (611) for blocking conductive paste and a printing part (612) for penetrating conductive paste. The particle size of the electromagnetic powder is smaller than the mesh diameter of the printing part (612).

3. The high-precision screen printing stencil detection device according to claim 1, characterized in that, The top of the display panel (5) is provided with a protective layer (51), which is a flexible protective layer.

4. The high-precision screen printing stencil detection device according to claim 1, characterized in that, The electromagnet (81) generates a vertically downward magnetic field when energized, and the electromagnetic powder has a tendency to shift downward under the magnetic field of the electromagnet (81).

5. The high-precision screen printing stencil detection device according to claim 1, characterized in that, The frame (1) is provided with a conveyor belt (4) for conveying the screen printing plate (6) on one side. The frame (1) is also provided with a feeding mechanism (3). The top of the frame (1) is provided with a feeding port (11) corresponding to the feeding mechanism (3). The feeding mechanism (3) is used to grab the screen printing plate (6) from the feeding port (11) for inspection.

6. The high-precision screen printing stencil detection device according to claim 5, characterized in that, The feeding mechanism (3) includes a second Y-axis module (31) fixed on the top of the frame (1), a second Z-axis module (32) fixed at the output end of the second Y-axis module (31), and a pneumatic clamp (33) fixed at the output end of the second Z-axis module (32).

7. The high-precision screen printing stencil detection device according to claim 5, characterized in that, The displacement mechanism (2) includes a first Z-axis module (21) fixed on the top of the frame (1), a first Y-axis module (22) fixed at the output end of the first Z-axis module (21), and a lifting cylinder (23) fixed at the output end of the first Y-axis module (22). There are two sets of lifting cylinders (23), one of which has its output end fixedly connected to the injection mechanism (8) and the electromagnet (81).

8. The high-precision screen printing stencil detection device according to claim 7, characterized in that, The output end of the other set of lifting cylinders (23) is fixed with a scraper (7).

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