Static hazard in a clean room
Accidents caused by static electricity in dust-free workshops have occurred frequently, so the anti-static ability of clean room has become a non-negligible aspect to evaluate its quality. The so-called static electricity is caused by friction or the like to destroy the uniform (+) negative <1) charge in the object, and the charge is excessive, and the object is in a charged state. Since these charges are not flowing at all times, Called static electricity.
Accidents caused by static electricity in a clean room have the following aspects:
1. Electrostatic electric shock caused by electrostatic electricity, causing human insecurity and fear, and can cause secondary injury (for example, a person falls due to electric shock, and falls and falls);
2. Widely used due to electrostatic discharge. The discharge current can cause damage and malfunction such as semiconductor components. For example, 50 P-MOS circuits are placed in a plastic bag. After shaking several times, the NAND gate gate is severely broken down by 39 pieces, and the failure rate is achieved. 78%, because semiconductor devices are very sensitive to electrostatic discharge;
3. Electromagnetic waves generated by electrostatic discharge in a clean room can cause noise and malfunction of electronic instruments and devices;
4. The luminescence of the electrostatic discharge can cause photo-damage of the photographic limbs and the like;
5. The mechanical phenomenon of static electricity in the dust-free workshop can cause the screen holes to be blocked by dust, the spinning yarns are disordered, the prints are uneven and the product is contaminated;
The occurrence of electrostatic accidents mainly lies in the generation and accumulation of static electricity, the flow of airflow, the friction of airflow and pipes, tuyères, filters, etc., the friction between the human body and clothes, the friction between clothes, the grinding on the process, the spraying, the jet, the washing , stirring, bonding and peeling, etc., all of which may generate static electricity. Under normal circumstances, the non-conductor (insulator) with low conductivity in the clean room is not easy to flow after the charge is generated, so the more Easy to charge.
The static problem in the dust-free workshop is particularly serious in the dust-free workshop because it not only has the above-mentioned various process factors for generating static electricity in the clean room, but also because many materials in the clean room such as plastic floor, wall, nylon, The uniforms and other uniforms all have high electrical resistivity, which are highly prone to static electricity and static electricity. These materials are widely used before the electrostatic disaster in the clean room is ignored.