What are the common faults and solutions of CCD contraposition suction and pasting machine?

The following are the common faults of CCD alignment suction and pasting machine, possible causes and solutions, which are explained by system classification:

First, the vision system (CCD) failure

1. The image is blurred or dark.

Reason:

The lens is dirty, the focal length is offset or the aperture is not set properly.

Insufficient brightness of light source, angle deviation or reflective interference.

The camera sensor is damaged or the cable contact is poor.

Solution:

Clean the lens with a dust-free cloth and readjust the focal length and aperture (it is recommended to use a calibration plate).

Calibrate the angle of light source (for example, annular light needs vertical illumination), increase the illumination intensity or change the type of light source (for example, backlight is suitable for transparent parts).

Check whether the camera cable is loose, and replace the damaged camera or light source controller.

2. The alignment deviation is large (exceeding ±0.05mm)

Reason:

The coordinate system is not calibrated (pixel-physical coordinate mapping error).

Mechanical vibration causes the camera or fixture to shift.

Improper setting of algorithm parameters (such as low edge detection threshold).

Solution:

Re-calibrate the coordinate system with the checkerboard calibration board to ensure that the pixel accuracy is ≤0.01mm/px.

Check whether the anchor screws of the equipment are fastened, and increase the damping pad (vibration acceleration should be ≤0.5g).

Optimize the algorithm parameters, such as increasing the template matching similarity threshold (recommended ≥0.95) or enabling dynamic compensation algorithm.

3. Poor identification (missed detection, false detection)

Reason:

The product has reflective surface, low color contrast or stains.

There is clutter interference in the field of view (FOV).

The color of the light source does not match the product (e.g. coaxial light is not used in the transparent part).

Solution:

Use polarized light source for reflective products, and increase backlight or ring light intensity for low contrast products.

Clean fixture and workbench, and adjust ROI (region of interest) to avoid interference area.

Change the color of light source (if blue light is suitable for green substrate) or add diffuser to reduce glare.

Second, the mechanical structure failure

1. Offset/jitter of suction head

Reason:

Wear of guide rail or lead screw and insufficient lubrication lead to jamming.

Perpendicular deviation of suction head (exceeding 0.05mm) or unstable air pressure.

Loose motor coupling or loose belt.

Solution:

Clean the guide rail and apply lithium-based grease, and check the wear of the lead screw (it needs to be replaced if the straightness exceeds 0.02mm).

Calibrate the verticality of the suction head with a laser interferometer and adjust the air pressure to a stable value (usually 0.5–0.7 MPa).

Tighten the coupling screw, and adjust the belt tension (measured by tensiometer, the standard value is 5N).

2. Fixture positioning deviation

Reason:

The fixture locating pin is worn and the mounting hole is loose.

The flatness of the stage is out of tolerance (> ＞0.02mm) or the screw is loose.

Solution:

Replace the worn locating pin, re-install the fixture and calibrate it with meter (positioning error ≤0.03mm).

Use a dial indicator to detect the flatness of the stage, adjust the horizontal screw or grind the table top.

3. Abnormal movement sound or jamming

Reason:

Foreign objects (such as dust and debris) enter the guide rail.

Motor overload (wrong parameter setting or excessive mechanical resistance).

Solution:

Remove the guide guard, clean the foreign matter with compressed air, and check the wear of the slider.

Reduce the moving speed (high speed ≤500mm/s) or reset the motor current parameters (no more than 80% of the rated value).

Three, pneumatic system failure

1. insufficient vacuum suction (<-50kpa)

Reason:

The suction nozzle is blocked (such as glue stains and debris) or damaged and leaks air.

The filter element of vacuum pump is dirty, the air pipe is bent or the solenoid valve is faulty.

Solution:

Clean the inside of the suction nozzle with alcohol, and replace the damaged suction nozzle (if the coaxiality deviation is greater than ＞0.03mm, it needs to be replaced).

Replace the filter element of vacuum pump, check the direction of air pipe (bending radius ≥10mm), and test whether the solenoid valve is on and off normally.

2. The suction head is stuck down/up.

Reason:

The pneumatic valve island is not well ventilated or the sealing ring is aging.

Cylinder guide rail parallelism deviation (> ＞0.1mm).

Solution:

Remove the valve island to clean the valve core and replace the aging sealing ring (it is recommended to replace it every 6 months).

Calibrate the parallelism of the cylinder guide rail with a square ruler, and adjust the mounting bracket until the error is less than or equal to 0.05 mm.

Four, electrical and control system failure

1. The sensor is triggered by mistake

Reason:

The photoelectric sensor is offset and interfered by strong light.

The detection distance of the proximity sensor is out of range (such as > 5 mm).

Solution:

Re-adjust the position of the sensor (keep the trigger distance at 2–4 mm) and add a hood to avoid the interference of ambient light.

Calibrate the detection distance of the sensor with a calibration block, and replace the sensor with insufficient sensitivity.

2. The equipment has no action/alarm.

Reason:

The emergency stop button is not reset and the safety grating is blocked.

Servo motor overload alarm (such as driver red light) or program error.

Solution:

Check the emergency stop loop and the light path of the safety grating, and remove obstructions.

Restart the device and reset the drive alarm, and re-import the correct program (the backup program needs to be checked regularly).

3. Data communication interruption

Reason:

Bad contact of network cable and USB cable or damaged interface.

The upper computer software is incompatible with the PLC version.

Solution:

Replace the shielded cable and check whether the pins of the interface are bent (it is recommended to use industrial-grade connectors with locks).

Upgrade the software driver or reinstall the matching communication protocol (such as Modbus TCP, Profinet).

V. Comprehensive performance failure

1. The production capacity is not up to standard (e.g. < 3000pcs/h).

Reason:

The motion parameters are set conservatively (such as low-speed alignment speed < 30 mm/s).

The visual processing time is too long (single frame > ＞200ms) or the head is waiting for temporal redundancy.

Solution:

Optimize the motion curve (such as increasing the acceleration and deceleration slope to 0.5m/s), and enable the "flight photo" function to reduce the pause.

Upgrade the camera frame rate (such as from 30fps to 60fps) or simplify the algorithm flow (such as pre-storing templates to reduce real-time calculation).

2. Low yield (< 95%)

Reason:

Multi-station cumulative error (such as conveyor belt positioning deviation).

Excessive suction nozzle pressure causes product damage (pressure > ＞10N).

Solution:

Add intermediate positioning stations (calibrate once every 5 stations) and use high-precision indexing discs (positioning accuracy 5 ").

Install real-time monitoring of pressure sensor (upper limit of 8N is recommended), and replace soft suction nozzle (such as silicone material).

Fault handling process suggestion

Quick positioning: reduce the fault range through equipment logs (such as alarm codes) and real-time monitoring interfaces (such as air pressure and motor current).

Classified inspection: verify step by step in the order of "vision → machinery → pneumatic → electrical", and give priority to simple faults (such as cleaning and restarting).

Preventive maintenance:

Daily: clean the lens and guide rail, and check the air tightness of the suction nozzle.

Weekly: lubricate the transmission parts and test the sensor sensitivity.

Monthly: calibrate the coordinate system and check the accuracy of motor encoder.

Record archiving: establish fault ledger, count high-frequency problems (such as nozzle blockage accounting for 40%), and optimize the process (such as adding automatic cleaning device).

Systematic troubleshooting and preventive maintenance can effectively reduce the downtime of equipment and improve the stability of production line.