Static Electricity Hazards in Microelectronics Clean Rooms
Increased static electricity will reduce the quality rate of electronic products, electromagnetic interference will interrupt the operation of automatic equipment, and electrostatic adsorption will increase the difficulty of collecting surface particles, so it is also necessary to control the generation of static electricity. Because electrostatic charges actually attract contaminants to product or tool surfaces, electrostatic adsorption is becoming a focus of attention in clean rooms. For example, when a 4-inch wafer is charged to 1KV, the adsorption force for particles with a diameter of 1 micron will reach 830,000 pounds per square inch. Therefore, electrostatic adsorption between charged objects and particles will be stronger than gravity, aerodynamic forces, and adhesion forces.
The main manifestations of static electricity hazards in clean workshops in the electronics industry include:
1. Absorb dust. Due to electrostatic adsorption, air particles in clean rooms are adsorbed on the surfaces of electronic components and walls, affecting product quality and cleanliness. Static electricity has also become a new source of dust in clean rooms.
2. Cause fires and explosions. A large amount of flammable and explosive gases, liquids and organic solvents are used in clean rooms in the electronics industry. Static electricity can become the ignition source of these gases (liquids) and solvents, causing fires or explosions.
3. Corona discharge, or spark discharge, emits noise and interferes with electronic equipment and electronic components.
4. Generate an electrostatic electric field, causing short circuit, fatigue or damage to electronic components.
For this reason, the continuous improvement of technology in the microelectronics industry is also a manifestation of the continuous improvement of anti-static technology. The content of electrostatic protection systems is becoming more and more abundant. In addition to conventional personnel protection systems (anti-static clothing, anti-static shoes, anti-static wrist straps, etc.), In addition to hardware protection systems such as static elimination equipment, what needs to be added more is the establishment of software electrostatic protection systems.