The importance of anti-static in electronic clean rooms
In daily work in clean rooms, accidents caused by static electricity occur frequently, so the anti-static ability of clean rooms has become an aspect that cannot be ignored when evaluating their quality.
What is static electricity? It is due to friction and other reasons that destroys the uniform electrical neutral state of equal amounts of positive (+) negative <1) charges in the object, causing excess charge and the object becoming charged. Because these charges usually do not flow. , so it is called static electricity.
Accidents caused by static electricity in clean rooms include the following aspects:
1. The luminescence of electrostatic discharge can cause photosensitive damage to photographic limbs;
2-Discharge current caused by electrostatic discharge can cause damage and malfunction of semiconductor components such as semiconductor components. For example, if 50 P-MOS circuits are placed in a plastic bag and shaken several times, the NAND gate gate will be seriously broken down. Count 39 block, the failure rate is as high as 78%. This is because semiconductor devices are very sensitive to electrostatic discharge;
3. Electromagnetic waves generated by electrostatic discharge can cause noise and malfunction of electronic instruments and devices;
4. The mechanical phenomenon of static electricity can cause the sieve holes to be blocked by dust, the spinning yarn is messy, the printed matter is uneven in depth and the finished product is contaminated;
5. The most dangerous disaster caused by electrostatic discharge is an explosion caused by a fire source of combustible materials. For example, according to foreign literature statistics, among the 86,000 times that explosive anesthetics were used in operating rooms, 36 explosions occurred, of which 21 were caused by static electricity. ;
The main causes of static electricity accidents are the generation and accumulation of static electricity, and the flow of air flow, friction between air flow and pipes, air vents, filters, etc., friction between the human body and clothes, friction between clothes, process grinding, spraying, jetting, and washing Operations such as stirring, adhesion and peeling, all of which may generate static electricity. In general, the smaller the conductivity of a non-conductor, the easier it is to become charged because it is difficult for the charge to flow after it is generated.
The problem of static electricity is particularly serious in clean rooms because not only are there a variety of process factors that generate static electricity in the clean room, but also because many materials in the clean room, such as plastic floors, walls, nylon, Qianliang and other work clothes, have a lot of High resistivity makes it easy to generate static electricity and accumulate static electricity. These materials were widely used before static electricity hazards in clean rooms were not taken seriously.