The usage specifications of air shower transfer Windows in the electronic semiconductor industry.

In the electronic semiconductor industry, air shower transfer Windows is the key equipment for maintaining a cleanroom environment. Their usage norms must strictly follow industry standards and cleanroom management requirements to ensure product quality and process stability. The following are the main usage norms and related requirements of the stroke transfer window in this industry:
I. Design and Installation Specifications
Cleanliness grade matching
The air shower transfer window with the corresponding filtration efficiency should be selected according to the cleanroom grade (such as ISO 5 grade, ISO 6 grade, etc.). Usually, high-efficiency filters (HEPA, filtration efficiency ≥99.97%@0.3μm) or ultra-high-efficiency filters (ULPA, filtration efficiency ≥99.9995%@0.12μm) are configured.
The internal material of the transfer window should be stainless steel (such as 304/316L), with a smooth surface, corrosion resistance, and no dust generation to avoid contamination of semiconductor components.
Airflow design requirements
It adopts a single-side or double-side air shower design, with a wind speed of ≥25m/s (in some high-cleanliness scenarios, it is required to be ≥30m/s), to ensure the rapid blowing off of particles on the surface of materials.
The airflow direction should form unidirectional or turbulent flow to avoid internal airflow dead corners and prevent cross-contamination.
Interlocking and sealing performance
Both sides of the door should be equipped with an electronic interlock function to ensure that when one side door is opened, the other side door automatically locks, preventing direct airflow between the clean room and the non-clean area.
The door gap should be sealed with silicone rubber strips. The overall sealing performance must pass leakage tests (such as smoke tests), with a leakage rate of ≤0.1%.
Ii. Standardized operation procedures
Preparation before use
The materials need to be pre-treated in a non-clean area first (such as removing the outer packaging and wiping the surface with alcohol) to avoid carrying dust into the transfer window.
Operators must wear anti-static clean suits, masks, and gloves. They can touch the transfer window only after being blown by the air shower room.
Transfer window operation steps
Insert materials: Open the outer door, smoothly place the materials into the transfer window, close the outer door, and make sure it is locked.
Air shower start-up: Set the air shower time through the control panel (usually 10 to 30 seconds, which needs to be adjusted according to the size of the material), and start the air shower program to ensure that the airflow thoroughly sweeps the surface of the material.
After the air shower is completed, the inner door is automatically unlocked. The operator takes out the materials from the clean room side and closes the inner door.
Exception handling: If the door is opened halfway or the air shower malfunctions, the air shower program needs to be re-executed.
Anti-static requirements
Anti-static countertops or conductive material trays should be installed inside the transfer window to prevent materials from attracting dust due to static electricity or causing damage to components.
Before touching the materials, the operator must wear an anti-static wristband and ensure that the transfer window is well grounded (grounding resistance ≤10Ω).
Iii. Cleaning and Maintenance Standards
Daily cleaning
Wipe the inner walls of the transfer window, door handles, and the air inlet of the filter with a lint-free cloth and 75% alcohol every day to remove residual particles and stains.
Volatile and corrosive cleaning agents (such as acetone) are prohibited to avoid contaminating the materials or corroding the inner wall.
Regular maintenance
Filter replacement:
Primary filter: Clean or replace it every 2 to 3 months (depending on the frequency of use).
High-efficiency/ultra-high-efficiency filters: Check the resistance (differential pressure gauge reading) annually. Replace when the resistance exceeds 1.5 to 2 times the initial value, or force replacement every 2 to 3 years (record the replacement time and differential pressure data).
Wind speed detection: Use an anemometer to measure the wind speed at the air outlet every quarter. If it is lower than 80% of the designed value, check the clogging of the filter or the performance of the fan.
Sealing test: Check for leakage in the door gaps through smoke tests annually. Replace the sealing strips if necessary.
Recording and Tracing
Establish an equipment maintenance ledger to record the cleaning, maintenance, filter replacement, and fault handling situations to ensure compliance with industry compliance requirements (such as ISO 14644, and SEMI standards).
Iv. Industry Standards and Compliance
International standard
Comply with standards such as ISO 14644-1 (Cleanrooms and related control environments) and **SEMI E14.4 (Electrostatic Control in Semiconductor Manufacturing) **.
For microelectronic devices (such as chips and wafers), compliance with JEDEC J-STD-033 (electrostatic Discharge Control) and ANSI/ESD S20.20 (Electrostatic Control Program) is required.
Domestic standard
Refer to GB/T 25915.1 (Cleanrooms and Related controlled Environments), GB 50073 (Code for Design of Cleanrooms), and electronic industry standards (such as SJ/T 11294-2003 "Code for Design of Cleanrooms in the Electronic Industry").
Certification Requirements
The air shower transfer Windows in key production processes need to pass third-party testing and certification (such as the certification of air velocity, filtration efficiency, and air tightness by cleanroom testing institutions) to ensure compliance with the requirements of customer or industry audits.
V. Precautions for Special Scenarios
Wafer/chip transfer
The materials should be placed in anti-static wafer boxes or dedicated trays to avoid direct exposure to airflow and prevent particle sedimentation.
The air shower time should be extended to 30 to 60 seconds to ensure thorough blowing of all six sides of the wafer box.
Chemical transfer
When transferring corrosive or volatile chemicals, sealed containers should be used, and leak-proof trays should be set at the bottom of the transfer window to prevent contamination of the filter or the inner wall.
After the transfer is completed, the interior of the transfer window should be cleaned immediately to prevent the volatilization of residual chemicals.
Transfer across clean areas.
When transferring materials from a lower-grade clean area to a higher-grade one, it is necessary to ensure that the internal pressure of the transfer window is consistent with that of the higher-grade area (monitored by a differential pressure gauge, with a pressure difference of ≥5Pa) to prevent reverse contamination.
Summary
The regulatory requirements for air shower transfer Windows in the electronic semiconductor industry are centered on "micro-pollution control" and "static electricity control", and strict control is needed throughout the entire process from design, operation, and maintenance to compliance. Through standardized usage norms, particle, microbial, and static contamination during the material transfer process can be effectively reduced, ensuring the yield and reliability of semiconductor products.