Key points for the daily maintenance of air shower transfer Windows in the electronic semiconductor industry.

In the electronic semiconductor industry, the daily maintenance of air shower transfer Windows is directly related to the pollution control effect of clean rooms and the service life of the equipment. The following are the core maintenance points summarized based on industry standards and practical experience, covering key links such as cleaning, component inspection, performance testing, and record management:
I. Daily Cleaning Standards
1. Surface cleaning
Cleaning frequency: once before and once after production every day (for areas with high cleanliness levels, cleaning is required per shift).
Cleaning tools: Use a lint-free cloth without fiber shedding (such as polyester fiber material) and a 75% alcohol solution (or a dedicated cleanroom cleaner).
Key points of operation:
Wiping sequence: From the top → the inner walls on both sides → the bottom → the door handle → the control panel. Avoid missing any corners.
Do not use ordinary rags, tap water, or sulfur/chlorine cleaners to prevent dust generation or corrosion of the stainless steel surface.
2. The air inlet of the filter is clean
Gently wipe the surface of the air inlet of the high-efficiency filter (HEPA/ULPA) with a lint-free cloth to remove visible dust and prevent blockage that may affect the airflow efficiency.
If severe dust accumulation is found at the air inlet, it is necessary to check whether the primary filter has failed (if the usage frequency is too high, the primary filter should be replaced in advance).
3. Anti-static surface maintenance
Wipe the anti-static countertop or tray inside the transfer window with an anti-static cleaner every week to ensure that the surface resistance value is maintained at 10⁶ - 10⁹Ω (regularly test with a surface resistance tester).
Ii. Inspection of Key Components
Door body and interlocking system
Inspection items:
Check whether the doors on both sides open and close smoothly, and whether there is any lag or abnormal noise.
Test the electronic interlock function: When one side of the door is opened, the other side of the door should not be able to open (the locking status can be determined by the indicator light or the buzzer).
Check whether the door gap sealing strip is aged, deformed, or damaged. If air leakage is found, it should be replaced in time (the service life of silicone rubber sealing strips is usually 2 to 3 years).
2. Fans and wind speed
Sound judgment: When starting the air spray, listen for the sound of the fan's operation to see if it is stable. If there is abnormal noise (such as vibration or howling), it may be due to dust accumulation on the impeller or bearing wear, and the machine needs to be stopped for cleaning or reported for repair.
Wind speed estimation: Bring your hand close to the air outlet to feel the intensity of the airflow. If it weakens significantly, further detection with an anemometer is required (standard wind speed ≥25m/s, it is recommended to measure it with an instrument once every quarter).
3. Control panel and Sensors
Check whether the buttons on the control panel are sensitive and whether the display screen is normal (such as whether the time and wind speed parameters are accurate).
Test the infrared sensor (if any): When the sensor is blocked, the air shower should start automatically. After removing the obstruction, the air shower should stop normally to avoid energy waste caused by accidental contact or malfunction.
Iii. Performance Testing and Maintenance Cycle
Filter maintenance
Key points for component maintenance cycle operation
The primary filter can be taken out every 2 to 4 weeks, rinsed with clean water (water temperature ≤40℃), dried, and then reinstalled. If the stain is stubborn or damaged, replace it directly.
For high-efficiency/ultra-high-efficiency filters, monitor the pressure difference before and after the filter with a differential pressure gauge every 6 to 12 months (or when the resistance exceeds the standard). Replace the filter when the resistance reaches 1.5 to 2 times the initial value.
Leakage tests (such as PAO tests) are required after replacement.
When replacing the filter, a clean suit must be worn and the operation should be carried out when the machine is shut down to prevent dust from entering the clean room. After replacement, record the installation date, model, and pressure difference data of the new filter.
2. Electrostatic control detection
Grounding resistance: Use a grounding resistance tester to test the grounding terminal of the transfer window every month. The resistance value should be ≤10Ω to ensure the effective discharge of static electricity.
Surface static electricity: Use an electrostatic voltage tester to test the anti-static countertop every quarter. The surface voltage after friction should be ≤100V (to avoid electrostatic adsorption of particles).
3. Air tightness test
Smoke test: Every year, use a smoke generator to inspect the door gaps and connections. If there is obvious smoke leakage (such as smoke streaks), adjust the position of the door body or replace the sealing strips.
Pressure difference monitoring: If the transfer window is connected to a pressure difference control system, it is necessary to ensure that the pressure difference on both sides meets the design requirements (for example, when transferring across clean areas, the pressure difference is≥5Pa).
Iv. Handling of Abnormal Situations
1. Common Faults and Solutions
Possible causes of fault phenomena and handling measures
If the air shower fails to start due to power failure, sensor malfunction, or interlock failure, check the power connection, clean the dust on the sensor surface, restart the equipment, or report for repair.
Insufficient air velocity causes the filter to clog, or the fan to malfunction. Replace the primary/high-efficiency filter, check if the fan impeller is dusty or if the bearings are damaged, and contact a professional for repair.
The door body cannot close, the sealing strip is deformed, and foreign objects are stuck. Clean the foreign objects in the door gap, adjust the door body hinge, or replace the sealing strip.
If the static electricity alarm has poor grounding or the anti-static material has failed, check the grounding wire connection, test the surface resistance, and replace the anti-static countertop or tray.
2. Emergency response
In case of sudden contamination inside the transfer window (such as liquid leakage or chemical evaporation), the machine should be stopped immediately, the materials removed, and the leaked substances cleaned with adsorption cotton and alcohol. If necessary, the filter should be isolated (such as temporarily covering it with dust-proof cloth) and a professional team should be notified for disinfection.
V. Records and Compliance Management
Maintain the ledger
Establish the "Maintenance Record Form for Wind Shower Transfer Window", the contents of which include:
Cleaning/maintenance date, operator;
Filter replacement time, model, and pressure difference data;
Fault handling situation (such as repair reporting time, maintenance content, acceptance result);
Performance test results (wind speed, electrostatic resistance, air tightness, etc.).
2. Compliance check
Regularly cooperate with third-party testing institutions to conduct cleanroom certification tests (such as once a year) to ensure that the performance of air shower transfer Windows complies with industry standards such as ISO 14644 and SEMI.
Maintenance records should be archived for at least three years for customer review or industry regulatory inspection.
Vi. Personnel Training and Management
Operation training: New employees must undergo training on the "Regulations for the Use and Maintenance of Air Shower Transfer Windows", and only after passing the assessment can they operate the equipment.
Assign responsibilities to individuals: Designate a specific person to be responsible for the daily cleaning and inspection of the transfer window, clarify job responsibilities, and avoid equipment failure caused by improper operation.
Summary
The maintenance of air shower transfer Windows in the electronic semiconductor industry should follow the principle of "prevention first and precise maintenance". Through high-frequency cleaning, periodic component inspection, and standardized record management, it is ensured that the equipment is always in an efficient operating state. At the same time, by integrating the dual requirements of static electricity control and micro-pollution prevention and control, the quality risks during the material transfer process can be minimized to the greatest extent, ensuring the stability of the semiconductor manufacturing process and the yield of products.