An automatic alignment device for partial printing
By combining the light source and the light receiver board with the light-blocking point design, automatic alignment between the circuit board and the graphic mesh is achieved, solving the problem of cumbersome alignment in the existing technology and improving printing efficiency and accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- FUJIAN FUQIANG PRECISION PRINTED CIRCUIT BOARD CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-06-02
AI Technical Summary
In existing technologies, the alignment process between the graphic mesh and the circuit board is cumbersome, resulting in low printing efficiency for large-size circuit boards, especially when partial printing requires multiple manual adjustments and trial prints.
The design employs a light source and a light receiver board in conjunction with light-blocking points. The alignment status between the circuit board and the graphic mesh is determined by the beam blocking. The alignment status is fed back in real time using photodetectors and indicator lights, and the mesh frame position is automatically adjusted to achieve efficient alignment without the need for transparent film trial printing.
It improves the production efficiency of circuit board printing, simplifies the alignment process, reduces manual intervention, and ensures the accuracy and efficiency of alignment.
Smart Images
Figure CN224311438U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of printed circuit board technology, and more specifically to an automatic alignment device for partial printing. Background Technology
[0002] Typically, screen printing technology is used to print the required characters on circuit boards. Screen printing technology mainly utilizes the basic principle that ink can pass through the mesh openings of the image area of the screen printing plate, while ink cannot pass through the mesh openings of the non-image area. During printing, ink is poured into one end of the screen printing plate, and a squeegee applies a certain pressure to the ink area on the screen printing plate. At the same time, the squeegee moves at a constant speed towards the other end of the screen printing plate. During the movement, the ink is squeezed from the mesh openings of the image area by the squeegee onto the substrate below.
[0003] like Figure 1 As shown, a typical screen printing machine for circuit boards includes:
[0004] 1. Frame; 2. Printing worktable; 3. Screen printing plate; 4. Position adjustment assembly; 5. Circuit board;
[0005] The screen printing plate 3 includes a graphic mesh 31 and a frame 32. The graphic mesh 31 is fixedly connected to the frame 32. The frame 32 is connected to the frame 1 through the position adjustment component 4. The screen printing plate 3 is located above the printing worktable 2. The circuit board 5 is fixedly installed on the printing worktable 2 and is also located below the graphic mesh 31.
[0006] Before printing, nails are inserted through the pre-drilled positioning holes on the circuit board and then into the printing table to fix the circuit board in place. The position of the screen printing frame is usually adjusted manually. Workers manually adjust the position of the screen printing plate using a position adjustment component, aligning the graphic screen with the circuit board. The graphic screen has mesh openings for both graphic and non-graphic areas. A transparent film is then applied to protect the circuit board, and a trial print is performed. A squeegee scrapes ink onto the graphic screen, printing text onto the transparent film. If the text printed in the trial print deviates from the specified position, the position adjustment component is manually operated again, and the transparent film is reapplied to protect the circuit board until the graphic screen is in the correct position, thus completing the alignment. Finally, the screen frame is locked in place for the final printing. This alignment method, involving applying a transparent film and first printing text on it, is cumbersome and inefficient.
[0007] Currently, for large-size circuit boards or circuit board printing with strict quality requirements, since the text printing area on the circuit board is larger than the graphic mesh on the screen printing board, a partial printing method is used. This involves first printing text in a localized area of the large-size circuit board, then adjusting the screen printing board to the next adjacent localized area and printing the text thereafter. After partial printing, alignment between the graphic mesh and the circuit board is required, and a transparent film is applied to the localized area of the circuit board. This means that a large PCB must undergo repeated alignment by applying transparent films, resulting in extremely low overall printing production efficiency.
[0008] Therefore, how to conveniently align the patterned mesh with the circuit board is a technical problem that urgently needs to be solved in this field. Utility Model Content
[0009] The technical problem to be solved by this utility model is to provide an automatic alignment device for partial printing, which can conveniently align the graphic mesh and the circuit board.
[0010] The technical solution adopted by this utility model is: an automatic alignment device for partial printing, comprising:
[0011] Frame, printing worktable, screen printing plate, position adjustment assembly, circuit board;
[0012] The screen printing plate includes a graphic mesh and a frame, the graphic mesh being fixedly connected to the frame, and the frame being connected to the machine frame via the position adjustment assembly. The screen printing plate is located above the printing worktable, and the circuit board is fixedly mounted on the printing worktable and located below the graphic mesh. It also includes:
[0013] Light source receiver board, light source;
[0014] The light source is fixedly mounted on the printing worktable and is located below the circuit board. The circuit board has alignment holes, and the graphic mesh fabric has light-blocking points. The light-blocking points are larger than the alignment holes. The light beam emitted by the light source passes through the alignment holes, and the light-blocking points are used to block the light beam emitted by the light source. The light source receiving plate is placed on the screen and is also located above the graphic mesh fabric.
[0015] Furthermore, the light source is a laser generator.
[0016] Furthermore, the light source receiving plate is a light screen.
[0017] Furthermore, the light source receiving plate is equipped with a photodetector, and the detection area of the photodetector covers the light-blocking point.
[0018] Furthermore, the light source receiving board is also provided with an indicator light, which is electrically connected to the photodetector.
[0019] Compared with the prior art, the beneficial effects or advantages of this utility model are as follows:
[0020] The light beam emitted by the light source passes through the alignment holes on the circuit board. When the light beam from the alignment holes is blocked by the light-blocking point of the graphic mesh, and the light source receiving board does not receive the light beam, it indicates that the alignment between the circuit board and the graphic mesh is complete. When the light beam from the alignment holes passes over the light-blocking point and hits the light source receiving board, it indicates that the alignment between the circuit board and the graphic mesh is not complete. At this time, the position of the graphic mesh is readjusted using the position adjustment component, and the light source receiving board is observed to determine whether the alignment is complete. There is no need to apply a protective film to the circuit board and test print text on the protective film. The alignment between the graphic mesh and the circuit board is convenient and helps to improve printing production efficiency. Attached Figure Description
[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0022] Figure 1 This is a schematic diagram of a conventional screen printing machine used for circuit boards in the background art.
[0023] Figure 2 This is a schematic diagram of the structure of an automatic alignment device for partial printing according to this utility model.
[0024] Figure 3 This is a schematic diagram showing that the circuit board and the graphic mesh are not properly aligned in this utility model.
[0025] Figure 4 This is a schematic diagram of the photodetector on the lower surface of the light source receiving plate in this utility model.
[0026] Figure 5 This is a schematic diagram showing the connection between the position adjustment component and the screen printing plate in this utility model.
[0027] Reference numerals: Frame 1; Scraper 11; Printing worktable 2; Nail 21; Screen printing plate 3; Graphic screen cloth 31; Screen frame 32; Light blocking point 33; Position adjustment assembly 4; First ball screw 41; Lateral moving base 42; Second ball screw 43; Longitudinal moving base 44; First handwheel 45; Second handwheel 46; Circuit board 5; Alignment drill hole 51; Light source receiving board 6; Photodetector 61; Light source 7. Detailed Implementation
[0028] This utility model embodiment provides an automatic alignment device for partial printing. The overall concept of the technical solution is as follows:
[0029] The graphic mesh fabric has mesh openings for graphic and non-graphic portions, both of which are translucent. In this invention, the graphic mesh fabric also includes light-blocking points that are opaque. Ink passes through the graphic mesh openings to form text on the circuit board.
[0030] During the previous process, alignment holes are pre-drilled on the circuit board. The positional relationship between the area to be printed on the circuit board and the alignment holes is consistent with the positional relationship between the mesh openings and the light-blocking points on the graphic screen. Therefore, when the light beam emitted from the light source of the printing table passes through the alignment holes on the circuit board, and is blocked by the light-blocking points, it indicates that the circuit board and the graphic screen are aligned. At this point, during printing, the squeegee scrapes ink on the graphic screen, and the ink passes through the mesh openings to print on the area of the text to be printed on the circuit board. If the light beam emitted from the alignment holes is not blocked by the light-blocking points and passes through the graphic screen to reach the light source receiving board, it indicates that the circuit board and the graphic screen are not aligned. In this case, the position of the graphic screen and the frame is adjusted until the light beam emitted from the alignment holes is blocked by the light-blocking points and does not reach the light source receiving board.
[0031] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0032] See Figures 1 to 5 The preferred embodiment of this utility model.
[0033] An automatic alignment device for partial printing includes:
[0034] 1. Frame; 2. Printing worktable; 3. Screen printing plate; 4. Position adjustment assembly; 5. Circuit board;
[0035] The screen printing plate 3 includes a graphic mesh 31 and a frame 32. The graphic mesh 31 is fixedly connected to the frame 32. The frame 32 is connected to the frame 1 through the position adjustment component 4. The screen printing plate 3 is located above the printing worktable 2. The circuit board 5 is fixedly installed on the printing worktable 2 and is also located below the graphic mesh 31. It also includes:
[0036] Light source receiver board 6, light source 7;
[0037] The light source 7 is fixedly installed on the printing workbench 2. The light source 7 is located below the circuit board 5. The circuit board 5 is provided with alignment drill holes 51. The graphic mesh fabric 31 is provided with light-blocking points 33. The light-blocking points 33 are larger than the alignment drill holes 51. The light beam emitted by the light source 7 passes through the alignment drill holes 51. The light-blocking points 33 are used to block the light beam emitted by the light source 7. The light source receiving plate 6 is placed on the mesh frame 32 and is also located above the graphic mesh fabric 31.
[0038] The beneficial effects or advantages of this utility model are as follows: The light beam emitted by the light source 7 passes through the alignment drill hole 51 of the circuit board 5. When the light beam coming out of the alignment drill hole 51 is blocked by the light-blocking point 33 of the graphic mesh fabric 31, and the light source receiving plate 6 does not receive the light beam, it indicates that the alignment of the circuit board 5 and the graphic mesh fabric 31 is complete. When the light beam coming out of the alignment drill hole 51 passes the light-blocking point 33 and hits the light source receiving plate 6, it indicates that the alignment of the circuit board 5 and the graphic mesh fabric 31 is not complete. At this time, the position of the graphic mesh fabric 31 is changed again by the position adjustment component 4, and the light source receiving plate 6 is observed to determine whether the alignment is complete. There is no need to apply a protective film to the circuit board 5 and test print text on the protective film. The alignment between the graphic mesh fabric 31 and the circuit board 5 is convenient and helps to improve printing production efficiency.
[0039] The graphic mesh fabric 31 has mesh holes for graphic and non-graphic parts. Both the graphic and non-graphic mesh holes are light-transmitting. In this utility model, the graphic mesh fabric 31 is also provided with light-blocking points 33, which are opaque. For example, the color of the light-blocking points 33 is black. The circuit board 5 has a pre-drilled alignment hole 51 during the previous process. The positional relationship between the area of the text to be printed on the circuit board 5 and the alignment hole 51 is consistent with the positional relationship between the mesh of the graphic part on the graphic screen 31 and the light blocking point 33. Therefore, when the light beam emitted from the light source 7 of the printing worktable 2 passes through the alignment hole 51 of the circuit board 5 and is blocked by the light blocking point 33, it means that the circuit board 5 and the graphic screen 31 are aligned. If the light beam emitted from the alignment hole 51 is not blocked by the light blocking point 33, but passes through the graphic screen 31 and is directed to the light source receiving plate 6, it means that the circuit board 5 and the graphic screen 31 are not aligned. At this time, the position of the graphic screen 31 and the frame 32 is adjusted until the light beam emitted from the alignment hole 51 is blocked by the light blocking point 33 and the light beam does not reach the light source receiving plate 6. After alignment is completed, the light source receiving board 6 is removed, ink is poured into the graphic mesh 31, and the squeegee 11 scrapes the ink, which is then printed onto the circuit board 5 through the mesh of the graphic portion of the graphic mesh 31.
[0040] In this embodiment, the printing worktable 2 is provided with a groove, the light source 7 is installed in the groove, the circuit board 5 is placed on the printing worktable, the alignment hole 51 of the circuit board 5 is aligned with the light source 7, when the light beam emitted by the light source 7 passes through the alignment hole 51, it indicates that the circuit board 5 is installed in the correct position, and the circuit board 5 is fixed to the printing worktable 2 using nails 21.
[0041] Furthermore, the light source 7 is a laser generator.
[0042] The beneficial effects of this technical solution are: laser has the characteristics of high brightness, high directionality and high monochromaticity. When the circuit board 5 is fixedly set on the printing worktable 2, the light source 7 is aligned with the alignment drill hole 51 of the circuit board 5; it is convenient to observe whether the laser from the alignment drill hole 51 hits the light source receiving plate 6.
[0043] Furthermore, the light source receiving plate 6 is a light screen.
[0044] The beneficial effects of this technical solution are as follows: The light screen is a screen that can receive light. When the light beam emitted by the light source 7 passes through the alignment hole 51 of the circuit board 5 and shines on the light screen, a bright spot is observed to appear on the light screen; when the light beam emitted by the light source 7 passes through the alignment hole 51 of the circuit board 5 but is not reached by the light screen, but is blocked by the light-blocking point 33, no bright spot is observed on the light screen; it is convenient to determine whether the graphic mesh 31 and the circuit board 5 have been aligned. The light source receiving plate 6 and the mesh frame 32 can be fixed with tape; after alignment is completed, the tape is removed and the light source receiving plate is taken away.
[0045] Furthermore, the light source receiving plate 6 is provided with a photodetector 61, and the detection area of the photodetector 61 covers the light-blocking point 33. This is another embodiment.
[0046] The beneficial effects of this technical solution are as follows: The photodetector 61 is located on the lower surface of the light source receiving plate 6. The photodetector 61 detects the intensity of light power, converts the light signal into an electrical signal, and sends it to the MCU. The MCU then determines whether a light beam has reached the light source receiving plate 6. When the light source receiving plate 6 is placed on the mesh frame 32, the position of the photodetector 61 on the light source receiving plate 6 is directly above the light-blocking point 33 of the patterned mesh 31. The light source receiving plate 6 can also be fully covered with photodetectors 61. A photodetector is also called a photodiode.
[0047] Furthermore, the light source receiving plate 6 is also provided with an indicator light (not shown), which is electrically connected to the photodetector 61.
[0048] The beneficial effects of this technical solution are as follows: The indicator light is located on the upper surface of the light source receiving board 6; when the photodetector 61 of the light source receiving board 6 detects the light beam, the photodetector 61 sends a signal to the MCU, and the MCU drives the indicator light to light up red, indicating that the alignment has failed; when the photodetector 61 does not detect the light beam, the MCU drives the indicator light to light up green, indicating that the alignment has been successful.
[0049] Each of the light-blocking points 33 has two or more. The number of alignment holes 51 is the same as the number of light-blocking points 33. This improves the alignment accuracy between the circuit board 5 and the pattern mesh 31. For large-sized circuit boards, each local area is provided with alignment holes; when the pattern mesh is directly above a local area of the circuit board, the alignment holes of the circuit board correspond one-to-one with the light-blocking points; when the pattern mesh has not moved directly above the next local area of the circuit board, the light beam emitted from the alignment holes of the circuit board in the next local area cannot reach the pattern mesh.
[0050] In this embodiment, the position adjustment component 4 includes a first ball screw 41, a lateral moving base 42, a second ball screw 43, and a longitudinal moving base 44. The lateral moving base 42 is connected to the frame 1 via the first ball screw 41, and the longitudinal moving base 44 is connected to the lateral moving base 42 via the second ball screw 43. The mesh frame 32 is fixedly connected to the longitudinal moving base 44. The first ball screw 41 moves the mesh frame 32 laterally, and the second ball screw 43 moves the mesh frame 32 longitudinally, thus enabling the position adjustment component 4 to change the position of the mesh frame 32 and the graphic mesh fabric 31. The first ball screw 41 and the second ball screw 43 are respectively equipped with a first handwheel 45 and a second handwheel 46, facilitating manual operation by the operator. After the graphic mesh fabric 31 and the circuit board 5 are successfully aligned, the first handwheel 45 and the second handwheel 46 are locked. The locking method can be achieved using existing technologies such as pin and positioning hole connections. In another embodiment, the first ball screw 41 and the second ball screw 43 are driven by a first servo motor (not shown) and a second servo motor (not shown), respectively, thereby automatically adjusting the position of the mesh frame 32. The MCU is electrically connected to the first and second servo motors. By fine-tuning the position of the mesh frame 32 in the horizontal and vertical directions, when the photodetector 61 of the light source receiving board 6 does not receive a light beam, the photodetector 61 sends a signal to the MCU, and the MCU stops the first and second servo motors, thereby locking the first ball screw 41 and the second ball screw 43.
[0051] The main principle of the automatic alignment device for partial printing of this utility model is as follows:
[0052] (1) The circuit board 5 has a 3.715mm diameter alignment hole 51 pre-drilled during the previous process.
[0053] (2) The circuit board 5 is fixedly mounted on the printing workbench 2 by nails 21. The light beam emitted by the light source 7 located on the printing workbench 2 can pass through the alignment drill hole 51 and illuminate the light source receiving board 6 when it is not blocked.
[0054] (3) When making the graphic mesh 31, a light-blocking point 33 with a diameter of 3.2mm is set at the position corresponding to the alignment drill hole 51 of the circuit board 5.
[0055] (4) Before printing, the position adjustment component 4 finely adjusts the moving screen 32. When the light source receiving plate 6 can no longer receive the light beam, that is, the light beam is blocked by the light blocking point 33, it indicates that the alignment is completed. Then, the position of the screen 32 is locked, and the text is printed onto the circuit board 5.
[0056] (5) After printing text in a local area of the circuit board 5, adjust the position of the screen frame 32 so that the screen frame 32 and the graphic screen 31 are directly above the next local area of the circuit board 5, and repeat the alignment printing operation. In this local printing, the circuit board 5 has more than two local areas, and each local area is provided with an alignment hole 51. Only when the screen frame 32 and the graphic screen 31 are directly above the corresponding local area will the light beam emitted by the light source 7 pass through the alignment hole 51 and reach the light source receiving plate 6 or be blocked by the light blocking point 33. The light source 7 does not emit light in other local areas of the circuit board 5.
[0057] In this embodiment, the light source 7 is used to directionally emit a beam of light, and can be a laser module or a highly indicative LED. A photosensitive element, such as a photodiode, photoresistor, or photodetector 61, can be disposed on the lower surface of the light source receiving board 6. The photosensitive element converts the light signal into an electrical signal and sends it to the MCU. The MCU determines whether the light intensity received by the photosensitive element reaches a threshold. When the light intensity received by the photosensitive element reaches the threshold, it indicates that the beam of light emerging from the alignment hole 51 is not blocked, and the alignment fails. When the light intensity received by the photosensitive element does not reach the threshold, it indicates that the beam of light emerging from the alignment hole 51 is blocked by the light-blocking point 33, and the alignment is successful.
[0058] The laser module selected for light source 7 has a wavelength of 650nm (red light), a power of 5mW, and a beam diameter of 1mm (small divergence angle, suitable for high precision). Light source 7 is fixedly mounted on the printing worktable 2, and the beam emitted by light source 7 is vertically upward.
[0059] The photodiode selected is model BPW34; the photodiode is positioned directly above the light-blocking point 33 of the graphic mesh 31, and the photodiode is 710 to 20 cm away from the light source; the photodiode is on the lower surface of the light source receiving plate 6, and the light source receiving plate 6 is placed on the mesh frame 32, that is, the photodiode is inside the mesh frame 32, so as to avoid the light from the external environment from interfering with the photodiode.
[0060] Before printing begins, the circuit board 5 to be printed is fixedly positioned on the printing worktable 2, and the light source 7 is turned on. When the beam of light emitted from the light source 7 can be emitted from the alignment hole 51 of the circuit board 5, it indicates that the placement of the circuit board 5 is correct. Then, the positions of the screen frame 32 and the graphic screen 31 are adjusted using the position adjustment component 4. If the beam of light emitted from the alignment hole 51 of the circuit board 5 can pass through the graphic screen 31 and then reach the light source receiving plate 6, the alignment has failed. The positions of the screen frame 32 and the graphic screen 31 are adjusted until the beam of light emitted from the alignment hole 51 of the circuit board 5 is blocked by the light-blocking point 33 of the graphic screen 31, and the beam does not reach the light source receiving plate 6, indicating that the alignment is successful. Convenient alignment between the graphic screen 31 and the circuit board 5 helps to improve printing production efficiency.
[0061] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. An automatic alignment device for partial printing, comprising: Frame, printing worktable, screen printing plate, position adjustment assembly, circuit board; The screen printing plate includes a graphic mesh and a frame, the graphic mesh being fixedly connected to the frame, and the frame being connected to the machine frame via the position adjustment component. The screen printing plate is located above the printing worktable, and the circuit board is fixedly mounted on the printing worktable and located below the graphic mesh. The feature is that it further includes: Light source receiver board, light source; The light source is fixedly mounted on the printing worktable and is located below the circuit board. The circuit board has alignment holes, and the graphic mesh fabric has light-blocking points. The light-blocking points are larger than the alignment holes, and the light beam emitted by the light source passes through the alignment holes. The light-blocking points are used to block the light beam emitted by the light source. The light source receiving plate is placed on the mesh frame and is also located above the graphic mesh fabric.
2. The automatic alignment device for partial printing according to claim 1, characterized in that, The light source is a laser generator.
3. The automatic alignment device for partial printing according to claim 1, characterized in that, The light source receiving board is a light screen.
4. The automatic alignment device for partial printing according to claim 1, characterized in that, The light source receiving plate is equipped with a photodetector, and the detection area of the photodetector covers the light-blocking point.
5. The automatic alignment device for partial printing according to claim 4, characterized in that, The light source receiving board is also equipped with an indicator light, which is electrically connected to the photodetector.