1. Vacuum leakage
Phenomenon: The vacuum degree cannot reach the set value or continues to decrease.
Reason:
The sealing ring is aging, cracking, or improperly installed.
Loose or small cracks in pipeline connections.
There are pinholes or welding defects on the vacuum chamber wall.
solve:
Regularly check the sealing ring and replace it every 6-12 months.
Use a helium mass spectrometer leak detector to locate the leak point, and after repair, re leak detection is required.
Perform pressure testing on the vacuum chamber.
2. Film layer detachment
Phenomenon: After coating, the film layer separates from the substrate or peels off in patches.
Reason:
Surface contamination of the substrate (oil stains, water vapor, dust).
Insufficient baking before coating.
Excessive membrane stress.
solve:
Strengthen substrate cleaning.
Install an ion source for pre plating bombardment cleaning.
Optimize process parameters.
3. The vacuum pump cannot start
Phenomenon: There is no response from the pump body after pressing the start button.
Reason:
Power failure (unstable voltage, short circuit in the circuit).
Motor damage or overheating protection triggered.
Oil contamination or insufficient oil level inside the pump.
solve:
Check the power supply circuit and voltage stability.
Replace the motor or wait for the pump body to cool down before restarting.
Regularly replace the vacuum oil and keep the oil level above the scale line.
4. Sudden decrease in vacuum degree
Phenomenon: The vacuum degree drops sharply during operation, making it impossible to maintain the process requirements.
Reason:
Pump malfunction.
Internal contamination inside the vacuum chamber.
Insufficient cooling water flow leads to overheating of the pump body.
solve:
Clean the diffusion pump annually and replace the specialized oil.
定期清理真空室。
Check the cooling water circuit to ensure a flow rate of ≥ 5L/min.
5. Uneven deposition of materials
Phenomenon: Inconsistent distribution of film thickness or composition on the substrate.
Reason:
Sedimentary source offset or unstable crucible rotation speed.
The substrate is not fixed or there is obstruction.
Magnetic/electric field interference causes beam deflection.
solve:
Adjust the position of the sediment source to ensure alignment with the center of the substrate.
Use fixtures to fix the base and avoid obstruction.
Check the parameters of the electromagnetic coil and optimize the beam trajectory.
6. Failure of film thickness control
Phenomenon: The deviation between the actual film thickness and the set value exceeds ± 5%.
Reason:
Calibration failure of crystal controller (membrane thickness gauge).
Probe position offset or contamination.
Fluctuations in process parameters (such as unstable evaporation rate).
solve:
Calibrate the crystal controller with standard film thickness sheets every quarter.
Clean the surface of the probe and adjust it to 5-10cm from the substrate.
Stabilize the power supply voltage to avoid sudden changes in parameters during the evaporation process.
7. Gas pollution leads to a decrease in membrane quality
Phenomenon: Pinholes, color spots, or reduced adhesion appear on the film layer.
Reason:
The vacuum chamber is not fully evacuated (residual water vapor, oxygen).
Air leaks during the coating process.
The film material absorbs moisture or contains impurities.
solve:
Vacuum to ≤ 5 × 10 ⁻⁴ Pa before coating, and bake to remove air.
Check all sealed interfaces and replace aging seals.
The film material needs to be pre melted and degassed in the vacuum chamber before use.
8. Heating system malfunction
Phenomenon: The substrate temperature cannot reach the set value or fluctuates excessively.
Reason:
Heating element is open or has poor contact.
Improper PID parameter setting of temperature controller.
Thermocouple position offset or damage.
solve:
Check the connection of the heating wire and replace the circuit breaker component.
Reset the parameters of the temperature controller.
Adjust the thermocouple to the center position of the substrate and calibrate it once a year.
9. Electronic control system malfunction
Phenomenon: The operation panel is unresponsive or the parameter display is abnormal.
Reason:
The control board is damp or dusty.
The sensor connection is loose or damaged.
Software program crashes.
solve:
Regularly clean the control cabinet with dry compressed air.
Check the sensor circuit and replace the faulty component.
Restart the system or reinstall the control software.
10. Abnormal filament/beam system
Phenomenon: No beam output or large beam fluctuation.
Reason:
The filament burns out or ages.
The beam limiter is not reset to zero or the potentiometer is faulty.
The high-voltage electrode protective cover is short circuited.
solve:
Replace the new filament and ensure it is centered during installation.
After pre melting, reset the beam limiter to zero before starting.
Check the insulation of the protective cover and clean the short-circuit point.