A highly automated PCB inspection apparatus

Abstract

The utility model provides a kind of high automation PCB detection equipment, including detection platform and top plate, six-axis robot is installed on detection platform, the movable platform of six-axis robot is installed with U-shaped detection seat, U-shaped detection seat is installed with clamping structure;Top plate is connected with first axial screw sliding table, first axial screw sliding table is connected with second axial screw sliding table by sliding block, first axial screw sliding table and second axial screw sliding table constitute perpendicular relationship;Second axial screw sliding table is connected with mounting plate by sliding block, the bottom of mounting plate is centrally installed with CCD detector, the bottom of mounting plate and the opposite sides of CCD detector are both installed with laser line scanning sensor, the bottom of mounting plate and the periphery of CCD detector and laser line scanning sensor are installed with multispectral LED annular light source;The position of the bottom of mounting plate and immediately adjacent CCD detector is installed with micro dispensing valve;2D appearance, 3D topography detection of PCB are completed, and defect position can be marked immediately.

Description

Technical Field

[0001] This utility model relates to the field of PCB inspection device technology, and in particular to a highly automated PCB inspection device. Background Technology

[0002] The existing technology, Chinese Patent Publication No. CN223513160U, published on November 4, 2025, discloses a PCB inspection device, belonging to the technical field of inspection devices. It includes an inspection table, a PCB board, a base plate, a top plate, a CCD detector, a moving component, an adjustable support component, a clamping component, and a flipping component. The base plate is fixedly installed on the top of the inspection table, and the top plate is located above the base plate. The moving component is installed at the bottom of the top plate to adjust the position of the CCD detector. Two sets of adjustable support components are provided. This invention, through the moving component, can move the CCD detector to perform visual inspection of the PCB board. The clamping component can clamp and fix the PCB board to be inspected above the base plate. After inspecting one side of the PCB board, the flipping component can flip the PCB board to facilitate visual inspection of the other side. This device allows for visual inspection of both sides of the PCB board in a single clamping operation, resulting in high inspection efficiency. The drawback of this existing technology is:

[0003] 1. Single detection mode: Only using CCD for two-dimensional appearance inspection, it is impossible to obtain key information such as the three-dimensional shape of the solder joint and the pin height, resulting in a high rate of missed detection of defects such as cold solder joints and bridging.

[0004] 2. Low clamping and positioning accuracy: The clamping assembly relies on mechanical springs (such as compression spring 14), and the clamping force is uncontrollable, which can easily damage precision components; the support plate is positioned by sliding between the slide plate and the T-shaped limit block, which results in accumulated gap error and affects the repeatability of positioning after flipping.

[0005] 3. Insufficient automation: The flipping component uses a common motor to drive the positioning frame to rotate as a whole, which has large inertia and slow speed; it lacks online calibration, adaptive adjustment and data interaction capabilities, and the whole process relies on manual intervention.

[0006] 4. Low system integration: Each component operates independently and is not interconnected with external production systems (such as MES), making it difficult to achieve quality traceability and predictive maintenance.

[0007] Therefore, the present invention aims to overcome the above-mentioned defects and provide a PCB inspection device that significantly improves the degree of automation and inspection accuracy in terms of structure. Utility Model Content

[0008] Based on this, the purpose of this utility model is to provide a highly automated PCB inspection device that can complete the 2D appearance and 3D morphology inspection of PCBs and mark the defect locations in real time.

[0009] This utility model provides a highly automated PCB inspection device, including an inspection table and a top plate. A six-axis robot is mounted on the inspection table, providing extremely high flexibility. It can move and rotate the PCB at any angle in space. For complex PCBs, it may be necessary to tilt the robot at a specific angle to allow the top sensor to better observe certain components or avoid obstruction. A U-shaped inspection seat is fixedly mounted on the moving platform of the six-axis robot via a flange. Clamping structures are installed on opposite sides of the U-shaped inspection seat. Multiple vacuum suction cups are installed on the upper surface of the U-shaped inspection seat to firmly adhere to the central area of ​​the PCB board.

[0010] The top plate is connected to a first axial lead screw slide via a lifting drive motor. The first axial lead screw slide is connected to a second axial lead screw slide via a slider. The first axial lead screw slide and the second axial lead screw slide are perpendicular to each other. The first axial lead screw slide and the second axial lead screw slide are combined to form a precision two-dimensional gantry, which can drive the sensor to be precisely positioned at any point above the PCB.

[0011] The second axial lead screw slide is connected to a mounting plate via a slider. A CCD inspection instrument is centrally mounted on the bottom of the mounting plate for high-resolution visual inspection, such as identifying misaligned components, missing components, incorrect polarity, and solder joint quality. Laser line scanning sensors are mounted on the bottom of the mounting plate, on opposite sides of the CCD inspection instrument. These sensors emit laser lines and analyze their deformation to accurately measure component height, warpage, and the 3D contour of solder. A multispectral LED ring light source is mounted on the bottom of the mounting plate, surrounding the CCD inspection instrument and the laser line scanning sensors, providing adjustable, shadow-free illumination for the CCD inspection instrument. Different angles and colors of light can highlight different features on the PCB (such as silkscreen printing, pads, and solder paste), greatly improving the accuracy of visual inspection. A miniature dispensing valve is mounted on the bottom of the mounting plate, adjacent to the CCD inspection instrument. Once a defect (such as a faulty capacitor) is detected, the system immediately controls the dispensing valve to move above the component, applying a small drop of colored ink or UV glue as a clear marker.

[0012] The four sides of the testing platform are machined with ceramic reference markers near the corners. Ceramic material is stable and has a low coefficient of thermal expansion. These markers provide a constant "geocentric coordinate system" for the entire system. Wide-angle calibration cameras are connected to the lower surface of the top plate and to opposite sides of the second axial lead screw slide via electric telescopic rods A. Before each test or periodically, these cameras descend to photograph the four ceramic markers. Through image recognition, minor deviations caused by temperature changes or mechanical vibrations can be automatically compensated for, ensuring that the coordinate systems of "sky" and "ground" remain consistent.

[0013] Preferably, a positioning pin is inserted on the upper surface of the U-shaped detection seat for initial positioning, ensuring that the PCB is placed in the same reference position each time, thereby improving the repeatability and accuracy of the detection.

[0014] Preferably, the clamping structure includes clamping blocks respectively disposed on opposite sides of the U-shaped detection seat and an electrically operated telescopic rod B connected to the corresponding clamping block. When the robot tilts significantly or moves at high speed, it can clamp the PCB from both sides to prevent it from sliding or tilting, ensuring absolute stability during the detection process.

[0015] Preferably, the surface of the vacuum suction cup is covered with a flexible pad to prevent the hard suction cup surface from scratching the delicate PCB circuit.

[0016] Preferably, a vibration sensor is installed at the end of the lead screw of the first axial lead screw slide, and a temperature sensor is attached to the bearing housing of the drive motor of the first axial lead screw slide.

[0017] Preferably, a vibration sensor is installed at the end of the lead screw of the second axial lead screw slide, and a temperature sensor is attached to the bearing housing of the drive motor of the second axial lead screw slide.

[0018] Preferably, the side of the clamping block that contacts the circuit board has a guide slope, which allows the clamping block to guide the PCB into place more smoothly when clamping, avoiding impact.

[0019] Vibration sensor: Monitors whether the lead screw vibrates abnormally due to wear or loosening. Vibration directly affects positioning accuracy.

[0020] Temperature sensor: Monitors whether the motor bearings are overheating due to prolonged operation or insufficient lubrication, enabling preventative maintenance and avoiding burnout.

[0021] The beneficial effects of this utility model are as follows:

[0022] 1. Highly integrated functions: It integrates 2D vision, 3D contouring, flexible fixtures, automatic marking and system calibration into one device, completing the complex inspection process that previously required multiple devices on a single device.

[0023] 2. High detection accuracy: By providing multi-angle detection poses through the robot, combined with a global vision calibration system and a precision ball screw slide, cumulative errors are effectively eliminated, ensuring the repeatability and accuracy of the detection results.

[0024] 3. High degree of automation: From fixing, calibration, scanning to marking, the entire process requires no manual intervention, which greatly improves production efficiency. Attached Figure Description

[0025] Figure 1 This is a three-dimensional view (top view) of the present invention.

[0026] Figure 2 This is a three-dimensional view (view from below) of the present invention.

[0027] Figure 3 This is a front view of the U-shaped detection seat.

[0028] The attached figures are labeled as follows: 11. Inspection table; 10. Top plate; 12. Lifting drive motor; 13. First axial lead screw slide; 14. Second axial lead screw slide; 15. Mounting plate; 16. Multispectral LED ring light source; 17. Miniature dispensing valve; 18. Positioning pin; 19. Empty suction cup; 20. Clamping block; 21. Electric telescopic rod B; 22. Wide-angle calibration camera; 23. Electric telescopic rod A; 24. Ceramic reference mark; 25. U-shaped inspection seat; 26. Six-axis robot; 27. Laser line scanning sensor; 28. CCD detector; 29. ​​Moving platform; 30. Flange; 31. Guide slope; 32. Circuit board. Detailed Implementation

[0029] To further understand the features, technical means, and specific objectives and functions achieved by this utility model, the following detailed description of this utility model is provided in conjunction with specific embodiments and accompanying drawings.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] Please refer to Figure 1-3As shown, a highly automated PCB inspection device includes an inspection table 11 and a top plate 10. A six-axis robot 26 is mounted on the inspection table 11. A U-shaped inspection seat 25 is fixedly mounted on the moving platform 29 of the six-axis robot 26 via a flange 30. Clamping structures are installed on opposite sides of the U-shaped inspection seat 25. Multiple vacuum suction cups 19 are mounted on the upper surface of the U-shaped inspection seat 25. In this embodiment, an SMC ZPT06BU type can be used. In this embodiment, the six-axis robot 26 can be a FANUC LRMate 200iD series. The top plate 10 is connected to a first axial lead screw slide 13 via a lifting drive motor 12. The first axial lead screw slide 13 is connected to a second axial lead screw slide 14 via a slider, and the first axial lead screw slide 13 and the second axial lead screw slide 14 are perpendicular to each other. The second axial lead screw slide 14 is connected to a mounting plate 15 via a slider. A CCD detector 28 is mounted in the center of the bottom of the mounting plate 15. Laser line scanning sensors 27 are mounted on the bottom of the mounting plate 15 and on opposite sides of the CCD detector 28. A multispectral LED ring light source 16 is mounted on the bottom of the mounting plate 15 and around the CCD detector 28 and the laser line scanning sensors 27. A miniature dispensing valve 17 is mounted on the bottom of the mounting plate 15 and adjacent to the CCD detector 28. In this embodiment, both the first axial lead screw slide 13 and the second axial lead screw slide 14 can be HIWIN KK series linear modules, the CCD detector 28 can be Keyence CV-X series, and the laser line scanning sensors 27 can be Keyence. LJ-V7080, the multispectral LED ring light source 16 can be CCS LDR2-90S2RYWC, and the miniature dispensing valve 17 can be Nordson EFD Ultra 2400 series.

[0032] Ceramic reference marks 24 are machined on the four sides of the testing table 11 near the corners. Wide-angle calibration cameras 22 are connected to the lower surface of the top plate 10 and to opposite sides of the second axial lead screw slide 14 via electric telescopic rods A23. In this embodiment, the electric telescopic rod A23 can be a Limtech LAF40 series, and the wide-angle calibration camera 22 can be a Hikvision MV-CH050-10UM industrial camera.

[0033] A positioning pin 18 is inserted into the upper surface of the U-shaped detection seat 25.

[0034] The clamping structure includes clamping blocks 20 respectively disposed on opposite sides of the U-shaped detection seat 25, and an electrically telescopic rod B21 connected to the corresponding clamping block 20. A guide slope 31 is formed on the side of the clamping block 20 that contacts the circuit board 32. In this embodiment, the Limtech LAF40 series...

[0035] The surface of the vacuum suction cup 19 has a flexible padding layer.

[0036] A vibration sensor is mounted on the end of the lead screw of the first axial lead screw slide 13, and a temperature sensor is attached to the bearing housing of the drive motor of the first axial lead screw slide 13. A vibration sensor is mounted on the end of the lead screw of the second axial lead screw slide 14, and a temperature sensor is attached to the bearing housing of the drive motor of the second axial lead screw slide 14. In this embodiment, the vibration sensor can be an IMI Sensors 608A11, and the temperature sensor can be a PT100 resistance temperature detector (RTD).

[0037] The workflow of this implementation method is as follows:

[0038] Loading and securing: The operator or robot places the PCB32 on the U-shaped detection seat 25, where it is initially positioned by the positioning pin 18. The vacuum suction cup 19 is powered on to attract the center of the PCB, and then the electric telescopic rods A21 on both sides push the clamping blocks 20 to clamp the PCB from the side.

[0039] System calibration: The electric telescopic rod B23 descends, allowing the wide-angle calibration camera 22 to capture images of the ceramic reference markers 24 at the four corners of the testing platform, thus completing coordinate system one.

[0040] Inspection and Scanning: The six-axis robot 26 moves the PCB to the inspection station according to instructions. The first-axis lead screw slide 13 and the second-axis lead screw slide 14 drive the sensor module to scan above the PCB. The multi-spectral LED ring light source 16 provides optimal illumination, the CCD detector 28 acquires 2D images, and the laser line scanning sensor 27 simultaneously acquires 3D height data.

[0041] Defect marking: The control system analyzes the collected data, and once a defect is identified, it immediately controls the two-dimensional slide to move the micro dispensing valve 17 directly above the defect and apply a marker.

[0042] Health monitoring: Throughout the process, vibration and temperature sensors continuously monitor the operating status of the slide. If the data is abnormal, an alarm will be triggered to prevent equipment failure.

[0043] The control principle of this implementation is as follows: The core of the equipment's control is the main controller, which is responsible for receiving user commands, parsing the detection process, and sending control signals to each execution unit. The entire control process follows a closed-loop logic of "initialization → fixing → calibration → scanning → analysis → marking," with the specific steps as follows:

[0044] 1. System initialization and self-test

[0045] After the main controller is powered on, it first performs a system self-test: checking the communication status of each motor driver and sensor, as well as the safety interlock signals.

[0046] Health monitoring sensors (vibration, temperature) upload data in real time. If the vibration amplitude exceeds a threshold (e.g., ±0.1 mm / s), the sensor will detect the vibration. 2 If the motor bearing temperature exceeds the safe range (e.g., ≥80℃), the controller will immediately trigger an alarm and suspend the process to prevent equipment damage.

[0047] 2. PCB Fixing Control

[0048] After the operator places the PCB on the U-shaped detection holder, the main controller executes the following steps in sequence:

[0049] Positioning control: The six-axis robot receives master control commands through its built-in controller and initially aligns the PCB with the positioning pins.

[0050] Adsorption and clamping control: The main controller opens the vacuum solenoid valve, causing the vacuum suction cup to generate negative pressure to adsorb the PCB; then the electric telescopic rod A is activated to push the clamping block to clamp the PCB from both sides.

[0051] Global calibration control

[0052] The main controller drives the electric telescopic rod B to descend, so that the wide-angle calibration camera can capture images of the ceramic reference markers at the four corners of the testing platform.

[0053] Images captured by the camera are transmitted to the main controller via gigabit Ethernet. The built-in image processing algorithm calculates the actual coordinates of the marker points and matches them with the theoretical coordinate systems of the robot and the slide, completing the multi-coordinate system unification. Calibration errors are automatically compensated for in subsequent motion commands.

[0054] 3. Detection and scanning control

[0055] The main controller coordinates the synchronous actions of the following units according to the preset path plan:

[0056] Six-axis robot: Carries PCB and tilts at multiple angles (e.g., ±30°) to eliminate blind spots in detection.

[0057] First axial lead screw slide 13 and second axial lead screw slide 14: The main controller controls the stepper / servo motor through pulse commands to drive the first and second axial lead screw slides to be precisely positioned in the XY plane, so that the sensor module covers the entire PCB area.

[0058] Light source and sensor triggering: The main controller adjusts the brightness and color temperature of the multispectral LED ring light source (via PWM signal) and simultaneously triggers the CCD detector and laser line scanning sensor to collect data.

[0059] 4. Defect Marking Control

[0060] When the data analysis module identifies a defect, the main controller immediately:

[0061] Calculate the coordinates of the defect point in the global coordinate system.

[0062] The two-dimensional slide is controlled to move the micro dispensing valve directly above the defect.

[0063] The output switch signal opens the dispensing valve to spray the marking material (such as UV glue). The spraying time and pressure are precisely controlled by preset parameters.

[0064] The signal processing flow of this embodiment is as follows:

[0065] The equipment signal processing is divided into four stages: "acquisition → preprocessing → feature extraction → decision-making," all of which are completed in the main controller or a connected industrial computer.

[0066] 1. Data Collection

[0067] CCD image data: The CCD inspection instrument acquires 2D grayscale or color images of the PCB at a high frame rate (e.g., 30fps) and transmits them via GigE Vision or USB 3.0 interface.

[0068] 3D contour data: A laser line scanning sensor emits a laser line and receives the reflected light, generating point cloud data through triangulation, which includes the (X,Y,Z) coordinates of each point.

[0069] Calibration data: Images of ceramic marker points taken by a wide-angle calibration camera, used for coordinate transformation matrix calculation.

[0070] Condition monitoring data: The vibration sensor outputs an acceleration signal, and the temperature sensor outputs a 4–20mA analog signal through a transmitter. Both are acquired by the PLC analog module.

[0071] 2. Data Preprocessing

[0072] Image enhancement: Filtering CCD images (such as median filtering for noise reduction), contrast stretching, and distortion correction to improve the signal-to-noise ratio.

[0073] Point cloud registration: The 3D point clouds collected by the laser sensor at different angles are fused into a complete 3D PCB model through the ICP (Iterative Closest Point) algorithm.

[0074] Coordinate unification: Using calibration data, all sensor data are transformed to the same global coordinate system to ensure data spatial consistency.

[0075] 3. Feature extraction and defect identification

[0076] 2D Defect Detection: Template matching or deep learning algorithms (such as pre-trained YOLO models) are used to identify defects such as misaligned components, missing components, and weld bridges in CCD images.

[0077] 3D parameter calculation: Extract features such as component height, solder volume, and board warpage from point cloud data and compare them with standard thresholds (e.g., height tolerance ±0.1mm).

[0078] Multi-sensor fusion: Integrating 2D and 3D analysis results—for example, if a component is correctly positioned in a 2D image but has an abnormal height in a 3D image, it is determined to be a "warping" defect.

[0079] 4. Decision-making and feedback

[0080] The main controller generates marking instructions based on the defect type and location, and records the defect log.

[0081] Real-time data (such as inspection progress and defect statistics) is displayed through the HMI interface and can be uploaded to the MES system via the OPC UA protocol.

[0082] If the same type of defect occurs repeatedly, the system can adaptively adjust the detection parameters (such as increasing the brightness of the light source or the scanning density) to achieve preliminary intelligent optimization.

[0083] The above-described embodiments are merely one implementation of this utility model, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A highly automated PCB inspection device, comprising an inspection table (11) and a top plate (10), characterized in that: A six-axis robot (26) is installed on the testing platform (11). The moving platform (29) of the six-axis robot (26) is fixedly installed with a U-shaped testing seat (25) through a flange (30). Clamping structures are installed on opposite sides of the U-shaped testing seat (25). Multiple vacuum suction cups (19) are installed on the upper surface of the U-shaped testing seat (25). The top plate (10) is connected to a first axial screw slide (13) via a lifting drive motor (12). The first axial screw slide (13) is connected to a second axial screw slide (14) via a slider. The first axial screw slide (13) and the second axial screw slide (14) are perpendicular to each other. The second axial screw slide (14) is connected to a mounting plate (15) via a slider. A CCD detector (28) is mounted in the center of the bottom of the mounting plate (15). Laser line scanning sensors (27) are mounted on the bottom of the mounting plate (15) and on both sides of the CCD detector (28). A multispectral LED ring light source (16) is mounted on the bottom of the mounting plate (15) and around the CCD detector (28) and the laser line scanning sensors (27). A miniature dispensing valve (17) is mounted on the bottom of the mounting plate (15) and adjacent to the CCD detector (28). Ceramic reference marks (24) are machined on the four sides of the detection stage (11) near the corners. Wide-angle calibration cameras (22) are connected to the lower surface of the top plate (10) and on both sides of the second axial screw slide (14) via electric telescopic rods A (23).

2. The highly automated PCB inspection equipment according to claim 1, characterized in that: A positioning pin (18) is inserted into the upper surface of the U-shaped detection seat (25).

3. The highly automated PCB inspection equipment according to claim 1, characterized in that: The clamping structure includes clamping blocks (20) respectively disposed on opposite sides of the U-shaped detection seat (25) and an electric telescopic rod B (21) connected to the clamping block (20) on the corresponding side.

4. The highly automated PCB inspection equipment according to claim 1, characterized in that: The surface of the vacuum suction cup (19) is covered with a flexible pad.

5. The highly automated PCB inspection equipment according to claim 1, characterized in that: A vibration sensor is installed at the end of the lead screw of the first axial lead screw slide (13), and a temperature sensor is attached to the drive motor bearing seat of the first axial lead screw slide (13).

6. The highly automated PCB inspection equipment according to claim 1, characterized in that: A vibration sensor is installed at the end of the lead screw of the second axial lead screw slide (14), and a temperature sensor is attached to the drive motor bearing seat of the second axial lead screw slide (14).

7. The highly automated PCB inspection equipment according to claim 3, characterized in that: A guide slope (31) is formed on the side of the clamp (20) that contacts the circuit board (32).

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