AOI detection equipment based on PCB production line and process thereof

Abstract

The application discloses an AOI detection equipment based on a PCB production line and a process thereof, and relates to the technical field of AOI detection equipment, and comprises a detection machine and a PCB board, and an executing mechanism support and an operation table are fixedly installed in the detection machine; the process further comprises the following steps: S1: a feeding and discharging conveying mechanism conveys the PCB board into the detection machine, and a placing frame receives the PCB board, at this time, a speed sensor is started and begins to collect an initial speed signal of a conveying belt. Advantages lie in that the equipment adopts three groups of differentiated light sources to adapt to plane defects, three-dimensional structures and special material areas, is matched with synchronous light filtering and light shielding design, reduces the missing detection rate of three-dimensional blind areas and the false detection rate of special materials, can further improve the precision through positioning compensation, and on the speed, the sensor adjusts the light source, the light filtering piece switching frequency and intelligently distributes the irradiation time length in real time, guarantees the constant unit length detection coverage, and provides a core guarantee for the stable operation of the AOI equipment in a complex production line environment.

Description

Technical Field

[0001] This invention relates to the field of AOI inspection equipment technology, and in particular to an AOI inspection equipment and process based on a PCB production line. Background Technology

[0002] In the mass production of PCBs (printed circuit boards), AOI (automatic optical inspection) equipment is a core component to ensure product quality. It is necessary to conduct comprehensive inspections on PCBs for planar circuit defects (such as missing prints and short circuits), three-dimensional structural defects (such as poor soldering of high-strength component solder joints and voids at the bottom of BGA solder joints), and special material areas (such as matte solder mask and transparent cover film).

[0003] Existing traditional equipment mostly uses a single or fixed-angle light source (such as direct white light), which cannot meet the inspection needs of different areas of the PCB: flat areas are prone to missing fine scratches due to uneven light intensity, the sides of tall components are blocked by shadows and blind spots, and recessed areas such as the bottom of BGA solder joints are difficult to identify because light cannot penetrate them; at the same time, for the special materials of matte solder mask (weak reflection) and transparent cover film (strong reflection), a single light source cannot form an effective light signal reflection.

[0004] To address these issues, we propose an AOI inspection device and process based on a PCB production line. Summary of the Invention

[0005] The purpose of this invention is to solve the problems mentioned in the background art, and to propose an AOI inspection device and process based on a PCB production line.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An AOI inspection device based on a PCB production line includes an inspection machine and a PCB board. The inspection machine is fixedly installed with an actuator bracket and an operating table. The operating table conveys the PCB board for inspection through a transmission device. The actuator bracket is equipped with two sets of light source detection components. The two sets of light source detection components are dynamically linked with the transmission device and switch the light source synchronously according to the PCB board conveying speed to achieve synchronous inspection of the PCB board's planar surface, three-dimensional structure, and special materials.

[0008] In the aforementioned AOI inspection equipment based on a PCB production line, an adjustment mechanism is fixedly installed on the actuator bracket. The adjustment mechanism is used to adjust the position of the light source detection component.

[0009] In the aforementioned AOI inspection equipment based on a PCB production line, the light source detection component includes a light source mounting base disposed on an adjustment mechanism. The light source mounting bases are evenly distributed along the inner circumference of the inner wall and are respectively a direct composite light source base, a 45° oblique infrared light source base, and a multispectral diffuse light source base.

[0010] In the aforementioned AOI inspection equipment based on a PCB production line, the direct composite light source holder is equipped with a dual-band LED array of 450nm blue light and 550nm green light for detecting PCB board planar printing defects, circuit defects, and shallow surface scratches; the 45° oblique infrared light source holder is equipped with an 850nm infrared LED with a divergence angle of 50° for detecting the sides of high components and the recessed areas at the bottom of BGA solder joints; and the multispectral diffuse light source holder is equipped with an adjustable spectrum LED of 400-700nm.

[0011] In the aforementioned AOI inspection equipment based on a PCB production line, a connecting frame is fixedly installed on one side of the light source mounting base, a light shield is fixedly installed at the lower end of the connecting frame, a fixed cover plate is fixedly installed on the actuator bracket, a torsion spring is fixedly installed on the lower surface of the fixed cover plate, a rotating rod is fixedly installed at the lower end of the torsion spring, and the rotating rod is rotatably mounted on the actuator bracket, and a toothed ring is fixedly installed at the lower end of the actuator bracket.

[0012] In the aforementioned AOI inspection equipment based on a PCB production line, a fixed frame is fixedly mounted on the rotating rod. A dual-band filter, a narrow-band filter, and a broadband filter are engaged on the fixed frame. The fixed frame rotates synchronously with the rotating rod, causing the dual-band filter, narrow-band filter, and broadband filter to sequentially switch into the optical path of the corresponding light source inside the light source mounting base. The dual-band filter filters ambient stray light from the direct composite light source, enhancing the contrast of the planar detection signal; the narrow-band filter isolates visible light interference from the infrared light source, improving the penetration of three-dimensional structure detection; and the broadband filter ensures the integrity of the optical signal from the multispectral light source, adapting to the detection of special materials.

[0013] In the aforementioned AOI inspection equipment based on a PCB production line, a vertical support is fixedly installed on the actuator bracket, a slide groove is opened on the vertical support, a toothed plate is slidably installed in the slide groove, three intervals are set between the teeth on the toothed plate, the interval ratio is 9:5:7, the toothed plate is used to mesh with the toothed ring, and a spring is provided on one side of the slide groove and the toothed plate.

[0014] In the aforementioned AOI inspection equipment based on a PCB production line, the transmission device includes motors fixedly installed at both ends of the operating table. A rotating shaft is rotatably installed at both ends of the operating table. Two pulleys are fixedly installed on the drive ends of the two rotating shafts and the two motors. A track is rotatably arranged between each pair of pulleys. Two pulleys are fixedly installed at both ends of the two rotating shafts. A conveyor belt is rotatably arranged between each pair of pulleys. Multiple placement racks are fixedly arranged between the two conveyor belts. Each PCB board is placed on a corresponding placement rack. Multiple spring shafts are fixedly installed on one of the conveyor belts, and a pusher plate is installed on each spring shaft.

[0015] In the aforementioned AOI inspection equipment based on a PCB production line, the actuator bracket is equipped with an adjustment mechanism and an XYZ axis motion module. The inspection machine is equipped with a loading and unloading conveyor mechanism for loading and unloading PCB boards. The inspection machine is equipped with two sets of alignment mechanisms for correcting the posture of the PCB boards. A PCB positioning sensor and a speed sensor are fixedly installed on the actuator bracket. The PCB positioning sensor is a photoelectric sensor, set corresponding to the positioning hole of the PCB board, and is used to detect the offset of the conveying position of the PCB board in real time. Its signal output terminal is electrically connected to the XYZ axis motion module to drive the adjustment mechanism to finely adjust the relative position of the light source mounting base and the filter. The speed sensor is installed on the rotating shaft of the conveyor belt to collect the real-time conveying speed of the PCB board. Its signal output terminal is connected to the motor to dynamically adjust the light source switching frequency, the filter switching frequency and match the conveyor belt speed.

[0016] A process for an AOI inspection device based on a PCB production line, using the aforementioned AOI inspection device based on a PCB production line, further includes the following steps:

[0017] S1: The loading and unloading conveyor mechanism transports the PCB board into the testing machine, and the placement rack supports the PCB board. At this time, the speed sensor is activated and begins to collect the initial speed signal of the conveyor belt.

[0018] S2: The PCB board moves with the conveyor belt to the alignment mechanism. The two sets of alignment mechanisms work together to correct the posture of the PCB board and ensure that the detection benchmark is consistent.

[0019] S3: The calibrated PCB board continues to be transported. The PCB positioning sensor detects the position of its positioning hole and feeds back the offset signal to the XYZ axis motion module in real time. This drives the adjustment mechanism to fine-tune the spatial position of the light source mounting base and completes the positioning compensation before detection.

[0020] S4: The motor drives the conveyor belt to run continuously. The speed sensor transmits the real-time speed signal to the light source detection component. The continuous rotation of the conveyor belt drives the push plate to move. The push plate contacts the corresponding toothed plate and pushes the toothed plate to move. Through the meshing transmission between the toothed plate and the toothed ring, the rotating rod and the fixed frame are driven to rotate, so as to realize the synchronous switching of the light source and the corresponding filter.

[0021] S5: The tooth spacing ratio of 9 corresponds to the direct composite light source, which makes the rotating rod drive the fixed frame to stay for the longest time, ensuring that the 450nm blue light and 550nm green light have sufficient irradiation time on the PCB board plane missing prints and circuit defects, and meet the signal acquisition requirements of fine scratches.

[0022] A tooth spacing ratio of 5 corresponds to a 45° oblique infrared light source, and the control rod dwell time is moderate, so that the irradiation time of 850nm infrared light on the side of high components and the bottom of BGA solder joints is adapted to the penetration requirements, avoiding overexposure or insufficient signal.

[0023] The tooth spacing ratio of 7 corresponds to a multispectral diffuse light source. The dwell time of the rotating rod can be adjusted to be between the two. The 400-700nm adjustable spectrum balances signal integrity and detection efficiency when irradiating matte solder resist and transparent cover film.

[0024] Meanwhile, the speed sensor transmits speed signals in real time and dynamically adjusts the frequency of the pusher plate pushing the toothed plate to ensure that the difference in irradiation time caused by the tooth spacing ratio under different conveying speeds always matches the detection requirements of each light source.

[0025] During the testing process, the dual-band filter, narrowband filter, and broadband filter are synchronously switched to the corresponding optical path along with the mounting frame;

[0026] S6: After the test is completed, the torsion spring releases its elastic potential energy to drive the rotating rod to return to its initial position. The conveyor belt transports the PCB board to the unloading end, and the loading and unloading conveyor mechanism removes the tested PCB board from the testing machine, completing a single test process.

[0027] Compared with existing technologies, the advantages of this invention are as follows: This device adopts three sets of differentiated light sources to adapt to planar defects, three-dimensional structures and special material areas, and is equipped with synchronous filtering and shading design to reduce the missed detection rate of three-dimensional blind spots and the false detection rate of special materials. It can also improve accuracy through positioning compensation. In terms of speed, the sensor adjusts the switching frequency of the light source and filter in real time and intelligently allocates the irradiation time to ensure a constant detection coverage per unit length, providing a core guarantee for the stable operation of AOI equipment in complex production line environments. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of an AOI inspection device based on a PCB production line proposed in this invention;

[0029] Figure 2This is a schematic diagram of the internal structure of the testing machine;

[0030] Figure 3 for Figure 2 A structural diagram from another perspective;

[0031] Figure 4 for Figure 3 Enlarged structural diagram of part a;

[0032] Figure 5 This is a structural schematic diagram of the actuator support;

[0033] Figure 6 This is a schematic diagram of the structure of the light source mounting base;

[0034] Figure 7 for Figure 6 A cross-sectional view of the structure along the AA direction.

[0035] In the diagram: 1. Inspection machine; 2. Motor; 3. Loading / unloading conveyor mechanism; 4. PCB board; 5. Human-machine interface; 6. Inspection door; 7. Rotary shaft; 8. Conveyor belt; 9. Actuator bracket; 10. Track; 11. Alignment mechanism; 12. Placement rack; 13. Adjustment mechanism; 14. Light source mounting base; 15. XYZ axis motion module; 16. Operating table; 17. Light shield; 18. Connecting frame; 19. Electric telescopic rod; 20. Dual-band filter; 21. Narrow-band filter; 22. Fixing frame; 23. Broadband filter; 24. Rotating rod; 25. Gear ring; 26. Gear plate; 27. Fixing cover plate; 28. Torsion spring; 29. ​​Vertical bracket; 30. Spring; 31. Push plate; 32. Spring shaft. Detailed Implementation

[0036] 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.

[0037] Reference Figures 1-4An AOI inspection device based on a PCB production line includes an inspection machine 1 and a PCB board 4. The inspection machine 1 has a human-machine interface 5 and a maintenance door 6 on its outer side. The human-machine interface 5 is used to preset inspection parameters and display inspection results, while the maintenance door 6 facilitates the maintenance and replacement of internal components. An actuator bracket 9 and an operating table 16 are fixedly installed inside the inspection machine 1. Two sets of light source detection components are mounted on the actuator bracket 9. These two sets of light source detection components are dynamically linked with the transmission device, synchronously switching the light source according to the conveying speed of the PCB board 4, enabling simultaneous inspection of the PCB board 4's planar, three-dimensional structures, and special materials. The actuator bracket 9 has a hollow aluminum alloy frame structure, combining rigidity and lightweight characteristics. An adjustment mechanism 13 is bolted to its top. The adjustment mechanism 13 includes a horizontal slide rail and a vertical lead screw. The horizontal slide rail adapts to the inspection requirements of PCB boards 4 of different widths, while the vertical lead screw is driven by a handwheel or motor, allowing for fine adjustment of the height of the light source detection components (adjustment range 50-150mm) to ensure that the distance between the light source and the surface of the PCB board 4 is always within the optimal inspection range.

[0038] The operating table 16 transmits PCB board 4 for testing via a transmission device. The transmission device includes motors 2, which are servo motors and have the characteristic of precise speed adjustment, fixedly installed at both ends of the operating table 16. Both ends of the operating table 16 are rotatably mounted with shafts 7 via deep groove ball bearings. Each shaft 7 and the drive end of each motor 2 is fixedly mounted with a pulley 1. A track 10 is rotatably installed between each pair of pulleys 1, enabling synchronous power transmission between the motors 2. Each end of the two shafts 7 is also fixedly mounted with pulleys 2. A conveyor belt 8 is rotatably installed between each pair of pulleys 2. The conveyor belt 8 is made of anti-static rubber. The material has anti-slip texture on the surface to prevent the PCB board 4 from slipping during transportation; multiple placement racks 12 are fixedly set between the two conveyor belts 8. The placement racks 12 are L-shaped stainless steel supports with polyurethane cushioning pads attached to their surfaces. Each PCB board 4 is placed on the corresponding placement rack 12 to achieve stable support of the PCB board 4; multiple spring shafts 32 are fixedly set on one of the conveyor belts 8. The spring shaft 32 consists of a shaft body and a compression spring sleeved on the outside of the shaft body. Each spring shaft 32 is hinged to a push plate 31 by a pin. The push plate 31 is made of arc-shaped nylon material to avoid rigid impact when in contact with the toothed plate 26.

[0039] Reference Figures 4-7The light source detection component includes a light source mounting base 14 mounted on the adjustment mechanism 13. The light source mounting base 14 is evenly distributed along the inner circumference of the inner wall and consists of a direct composite light source base, a 45° oblique infrared light source base, and a multispectral diffuse light source base. The direct composite light source base is equipped with a dual-band LED array of 450nm blue light and 550nm green light. The direct composite light source base has a heat dissipation channel inside and is equipped with a dual-band LED array of 450nm blue light and 550nm green light (power 15W). The LED array is connected in series and is used with a frosted lens to achieve uniform light diffusion. It is used for the detection of PCB board planar printing defects, circuit defects and shallow surface scratches. The 45° angled infrared light source holder mounts an 850nm infrared LED with a divergence angle of 50°. The mounting angle of the 45° angled infrared light source holder can be finely adjusted with bolts. It has a built-in 850nm infrared LED and a light shield with a 17-section extension on the outside of the light holder to prevent direct light from interfering with other detection areas. It is used for detecting the side of high components and the recessed area at the bottom of BGA solder joints. The multispectral diffuse light source holder mounts a 400-700nm adjustable spectrum LED (10W power). The front end of the light holder is fixed with a diffuse reflector plate by a clip. The diffuse reflector plate is made of milky white acrylic material with a frosted surface. It is used for detecting matte solder resist layers and transparent cover film areas.

[0040] A connecting bracket 18 is fixedly installed on one side of the light source mounting base 14, and a light shield 17 is fixedly installed at the lower end of the connecting bracket 18. The light shield 17 is an elastic wedge structure, consisting of an outer layer of 60A hardness black silicone, a middle layer of 0.5mm thick 304 stainless steel skeleton, and an inner layer of 2mm thick aerogel heat insulation layer. The bonding pressure with the surface of the PCB board 4 is ≤0.4N, which can isolate ambient light and avoid scratching the surface of the PCB board 4.

[0041] A fixed cover plate 27 is fixedly installed on the actuator bracket 9. A torsion spring 28 is fixedly installed on the lower surface of the fixed cover plate 27. A rotating rod 24 is fixedly installed at the lower end of the torsion spring 28 and is rotatably mounted on the actuator bracket 9. A toothed ring 25 is fixedly installed at the lower end of the actuator bracket 9. A fixed frame 22 is fixedly installed on the rotating rod 24. The fixed frame 22 is an annular aluminum alloy frame with three elastic claws on its inner side. A dual-band filter 20, a narrow-band filter 21, and a broadband filter 23 are engaged on the fixed frame 22. Silicone buffer pads are pasted on the inner side of the claws to ensure that the filters are installed firmly and without damage. The mounting bracket 22 rotates synchronously with the rotating rod 24, causing the dual-band filter 20, narrow-band filter 21, and broadband filter 23 to sequentially switch into the optical path of the corresponding light source inside the light source mounting base 14. The dual-band filter 20 has a bandwidth of 20nm each and is used to filter ambient stray light from the direct composite light source, enhancing the contrast of the planar detection signal. The narrow-band filter 21 has a bandwidth of 40nm and is used to isolate visible light interference from the infrared light source, improving the penetration of the three-dimensional structure detection. The broadband filter 23 has a transmission range of 400-700nm and is used to ensure the integrity of the optical signal of the multispectral light source, adapting to the detection of special materials.

[0042] A vertical support 29 is fixedly mounted on the actuator bracket 9. A sliding groove is formed on the vertical support 29, and a toothed plate 26 slides within the groove. Three intervals are provided between the teeth on the toothed plate 26, with an interval ratio of 9:5:7, corresponding to the required dwell time of the light source. The toothed plate 26 meshes with a toothed ring 25. A spring 30 is provided on one side of the groove and the toothed plate 26 to ensure smooth sliding of the toothed plate 26 and its automatic return to its original position.

[0043] An electric telescopic rod 19 is fixedly installed on the actuator bracket 9. The telescopic end of the electric telescopic rod 19 is connected to the connecting frame 18 and can be used to fine-tune the horizontal position of the light source mounting base 14. The outer side of the fixed frame 22 is provided with scale markings to facilitate the calibration of the filter switching position.

[0044] An adjustment mechanism 13 and an XYZ axis motion module 15 are provided on the actuator bracket 9. The inspection machine 1 is provided with a loading and unloading conveyor mechanism 3 to load and unload the PCB board 4. The loading and unloading conveyor mechanism 3 is a belt conveyor structure, which is at the same height as the conveyor belt 8 inside the inspection machine 1. A guide ramp is provided at the connection to achieve a smooth transition of the PCB board 4. It is used to load and unload the PCB board 4.

[0045] The inspection machine 1 is equipped with two sets of alignment mechanisms 11, which are used to correct the posture of the PCB board 4. A PCB positioning sensor and a speed sensor are fixedly installed on the actuator bracket 9. The PCB positioning sensor is a diffuse reflection photoelectric sensor with a detection distance of 5-50mm. It is set to correspond to the positioning hole of the PCB board 4 and is used to detect the offset of the conveying position of the PCB board 4 in real time. Its signal output terminal is electrically connected to the XYZ axis motion module 15 to drive the adjustment mechanism 13 to finely adjust the relative position of the light source mounting base 14 and the filter. The speed sensor 34 is an incremental encoder, which is installed on the rotating shaft 7 of the conveyor belt 8 and is used to collect the real-time conveying speed of the PCB board 4. Its signal output terminal is connected to the motor 2 to dynamically adjust the light source switching frequency, the filter switching frequency and match the speed of the conveyor belt 8.

[0046] The specific operation steps of this invention are as follows:

[0047] S1: The loading and unloading conveyor mechanism 3 transports the PCB board 4 into the testing machine 1, and the placement rack 12 supports the PCB board 4. At this time, the speed sensor is activated and begins to collect the initial speed signal of the conveyor belt 8.

[0048] S2: PCB board 4 moves with conveyor belt 8 to the alignment mechanism 11. The two sets of alignment mechanisms 11 work together to correct the posture of PCB board 4 and ensure that the detection benchmark is consistent.

[0049] S3: The calibrated PCB board 4 continues to be transported. The PCB positioning sensor detects the position of its positioning hole and feeds back the offset signal to the XYZ axis motion module 15 in real time. The adjustment mechanism 13 drives the light source mounting seat 14 to fine-tune the spatial position of the light source mounting seat 14 and completes the positioning compensation before detection.

[0050] S4: Motor 2 drives conveyor belt 8 to run continuously. Speed ​​sensor 34 transmits real-time speed signal to light source detection component. Conveyor belt 8 rotates continuously, driving push plate 31 to move. Push plate 31 contacts corresponding toothed plate 26, pushing toothed plate 26 to move. Through the meshing transmission of toothed plate 26 and toothed ring 25, rotating rod 24 and fixed frame 22 are driven to rotate, realizing synchronous switching of light source and corresponding filter.

[0051] S5: The tooth spacing ratio of 9 corresponds to the direct composite light source, which makes the rotating rod 24 drive the fixed frame 22 to stay for the longest time, ensuring that the 450nm blue light and 550nm green light have sufficient irradiation time on the PCB board plane missing prints and circuit defects, and meet the signal acquisition requirements of fine scratches.

[0052] The tooth spacing ratio of 5 corresponds to a 45° oblique infrared light source, and the dwell time of the control rod 24 is moderate, so that the irradiation time of the 850nm infrared light on the side of the component and the bottom of the BGA solder joint is adapted to the penetration requirements, avoiding overexposure or insufficient signal.

[0053] The tooth spacing ratio of 7 corresponds to a multispectral diffuse light source. The dwell time of the adjustable rotating rod 24 is between the two, so that the irradiation time of the 400-700nm adjustable spectrum on the matte solder resist layer and the transparent cover film takes into account both signal integrity and detection efficiency.

[0054] Meanwhile, the speed sensor transmits speed signals in real time and dynamically adjusts the frequency at which the pusher plate 31 pushes the toothed plate 26 to ensure that the difference in irradiation time caused by the tooth spacing ratio under different conveying speeds always matches the detection requirements of each light source.

[0055] During the testing process, the dual-band filter 20, narrowband filter 21, and broadband filter 23 are synchronously switched to their corresponding optical paths along with the mounting bracket 22;

[0056] S6: After the test is completed, the torsion spring 28 releases its elastic potential energy to drive the rotating rod 24 to return to its initial position. The conveyor belt 8 transports the PCB board 4 to the unloading end. The loading and unloading conveying mechanism 3 removes the tested PCB board 4 from the testing machine 1, completing a single test process.

[0057] To further clarify, the aforementioned fixed connection should be interpreted broadly unless otherwise explicitly specified and limited. For example, it may be welding, gluing, or integral molding, or other conventional methods well known to those skilled in the art.

[0058] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An AOI inspection device based on a PCB production line, comprising an inspection machine (1) and a PCB board (4), characterized in that, The testing machine (1) is fixedly installed with an actuator bracket (9) and an operating table (16). The operating table (16) transmits the PCB board (4) for testing through a transmission device. The actuator bracket (9) is equipped with two sets of light source detection components. The two sets of light source detection components are linked with the transmission device and switch the light source synchronously according to the conveying speed of the PCB board (4) to realize the synchronous detection of the plane, three-dimensional structure and special materials of the PCB board (4). An adjustment mechanism (13) is fixedly installed on the actuator bracket (9). The adjustment mechanism (13) is used to adjust the position of the light source detection component. The light source detection assembly includes a light source mounting base (14) disposed on the adjustment mechanism (13). The light source mounting base (14) is evenly distributed along the inner circumference of the inner wall and consists of a direct composite light source base, a 45° oblique infrared light source base, and a multispectral diffuse light source base. The direct-light composite light source holder is equipped with a dual-band LED array of 450nm blue light and 550nm green light for detecting PCB board planar printing defects, circuit defects, and shallow surface scratches; the 45° oblique infrared light source holder is equipped with an 850nm infrared LED with a divergence angle of 50° for detecting the sides of high components and the recessed areas at the bottom of BGA solder joints; the multispectral diffuse light source holder is equipped with an adjustable spectrum LED of 400-700nm. A fixed cover plate (27) is fixedly installed on the actuator bracket (9). A torsion spring (28) is fixedly installed on the lower surface of the fixed cover plate (27). A rotating rod (24) is fixedly installed at the lower end of the torsion spring (28), and the rotating rod (24) is rotatably mounted on the actuator bracket (9). A toothed ring (25) is fixedly installed at the lower end of the actuator bracket (9). A fixed frame (22) is fixedly installed on the rotating rod (24), and a dual-band filter is engaged on the fixed frame (22). The device includes a light filter (20), a narrowband filter (21), and a broadband filter (23). A vertical support (29) is fixedly installed on the actuator bracket (9). A sliding groove is provided on the vertical support (29). A toothed plate (26) is slidably installed in the sliding groove. There are three intervals between the teeth on the toothed plate (26) with an interval ratio of 9:5:

7. The toothed plate (26) meshes with a toothed ring (25). A spring (30) is provided on one side of the sliding groove and the toothed plate (26).

2. The AOI inspection equipment based on a PCB production line according to claim 1, characterized in that, A connecting frame (18) is fixedly provided on one side of the light source mounting base (14), and a light shield (17) is fixedly provided at the lower end of the connecting frame (18).

3. The AOI inspection equipment based on a PCB production line according to claim 2, characterized in that, The fixed frame (22) rotates synchronously with the rotating rod (24), causing the dual-band filter (20), narrowband filter (21) and wideband filter (23) to be switched sequentially into the optical path of the corresponding light source inside the light source mounting base (14). The dual-band filter (20) is used to filter the ambient stray light of the direct composite light source and enhance the contrast of the planar detection signal; the narrowband filter (21) is used to isolate the visible light interference of the infrared light source and improve the penetration of the three-dimensional structure detection; the wideband filter (23) is used to ensure the integrity of the light signal of the multispectral light source and adapt to the detection of special materials.

4. The AOI inspection equipment based on a PCB production line according to claim 3, characterized in that, The transmission device includes motors (2) fixedly installed at both ends of the operating table (16). Both ends of the operating table (16) are rotatably mounted with rotating shafts. Each of the two rotating shafts and the drive ends of the two motors (2) are fixedly mounted with pulleys. A track (10) is rotatably arranged between each pair of pulleys. Each end of the two rotating shafts is fixedly mounted with pulleys. A conveyor belt (8) is rotatably arranged between each pair of pulleys. Multiple placement racks (12) are fixedly arranged between the two conveyor belts (8). Each PCB board (4) is placed on the corresponding placement rack (12). Multiple spring shafts (32) are fixedly arranged on one of the conveyor belts (8). Each spring shaft (32) is equipped with a push plate (31).

5. The AOI inspection equipment based on a PCB production line according to claim 4, characterized in that, The actuator bracket (9) is equipped with an adjustment mechanism (13) and an XYZ axis motion module (15). The inspection machine (1) is equipped with a loading and unloading conveying mechanism (3) to load and unload the PCB board (4). The inspection machine (1) is equipped with two sets of alignment mechanisms (11) for posture correction of the PCB board (4). The actuator bracket (9) is fixedly equipped with a PCB positioning sensor and a speed sensor. The PCB positioning sensor is a photoelectric sensor, corresponding to the PCB. The positioning holes of the board (4) are used to detect the offset of the conveying position of the PCB board (4) in real time. Its signal output terminal is electrically connected to the XYZ axis motion module (15) to drive the adjustment mechanism (13) to finely adjust the relative position of the light source mounting base (14) and the filter. The speed sensor (34) is installed on the rotating shaft (7) of the conveyor belt (8) to collect the real-time conveying speed of the PCB board (4). Its signal output terminal is connected to the motor (2) to dynamically adjust the light source switching frequency, the filter switching frequency and match the speed of the conveyor belt (8).

6. A process for an AOI inspection device based on a PCB production line, using the AOI inspection device based on a PCB production line as described in claim 5, characterized in that, It also includes the following steps: S1: The loading and unloading conveyor (3) transports the PCB board (4) into the testing machine (1), and the placement rack (12) supports the PCB board (4). At this time, the speed sensor starts and begins to collect the initial speed signal of the conveyor belt (8). S2: The PCB board (4) moves with the conveyor belt (8) to the alignment mechanism (11). The two alignment mechanisms (11) work together to correct the posture of the PCB board (4) and ensure that the detection benchmark is consistent. S3: The calibrated PCB board (4) continues to be transported. The PCB positioning sensor detects the position of its positioning hole and feeds back the offset signal to the XYZ axis motion module (15) in real time. The adjustment mechanism (13) is driven to finely adjust the spatial position of the light source mounting seat (14) to complete the positioning compensation before detection. S4: The motor (2) drives the conveyor belt (8) to run continuously. The speed sensor (34) transmits the real-time speed signal to the light source detection component. The continuous rotation of the conveyor belt (8) drives the push plate (31) to move. The push plate (31) contacts the corresponding toothed plate (26) and pushes the toothed plate (26) to move. Through the meshing transmission of the toothed plate (26) and the toothed ring (25), the rotating rod (24) and the fixed frame (22) are driven to rotate, so as to realize the synchronous switching of the light source and the corresponding filter. S5: The tooth spacing ratio of 9 corresponds to the direct composite light source, so that the rotating rod (24) drives the fixed frame (22) to stay for the longest time, ensuring that the 450nm blue light and 550nm green light have sufficient irradiation time for the PCB board plane missing prints and line defects, and meet the signal acquisition requirements of fine scratches. The tooth spacing ratio of 5 corresponds to a 45° oblique infrared light source. The control rod (24) stays for a medium time, so that the irradiation time of 850nm infrared light on the side of the high component and the bottom of the BGA solder joint is adapted to the penetration requirements, avoiding overexposure or insufficient signal. The tooth spacing ratio of 7 corresponds to a multispectral diffuse light source. The dwell time of the adjustable rotating rod (24) is between the two. The irradiation time of the matte solder resist layer and the transparent cover film with the adjustable spectrum of 400-700nm takes into account both signal integrity and detection efficiency. At the same time, the speed sensor transmits speed signals in real time and dynamically adjusts the frequency at which the push plate (31) pushes the tooth plate (26) to ensure that the difference in irradiation time caused by the tooth spacing ratio under different conveying speeds always matches the detection requirements of each light source. During the detection process, the dual-band filter (20), narrowband filter (21), and broadband filter (23) are switched to their corresponding optical paths synchronously with the fixture (22); S6: After the test is completed, the torsion spring (28) releases its elastic potential energy to drive the rotating rod (24) to reset to the initial position. The conveyor belt (8) transports the PCB board (4) to the unloading end. The loading and unloading conveyor mechanism (3) removes the tested PCB board (4) from the testing machine (1) to complete the single test process.

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