The number of fine dust below 0.5 micron per cubic meter is controlled below 3500, reaching the international dust-free standard A level. At present, the dust-free standard adopted in chip-level production and processing has higher requirements for dust than A-level, and this high standard is mainly used for some higher-level chip production. The amount of fine dust is strictly controlled within 0/000 per cubic meter/kloc, which is also called one thousandth in the industry.
The selection of clean workshop address should follow the principles of favorable production, convenient life, saving investment and operating expenses. The distance between the dust-free workshop and the main traffic road should be more than 50 meters.
The site should be selected in an area with good natural environment and water quality, low atmospheric dust concentration and microclimate caused by topography and landforms, which is conducive to production and energy saving. Stay away from areas that emit a lot of dust, smoke, toxic gases and microorganisms. , such as airports, railways, docks, traffic arteries, etc. , the windward side of the pollution source and the dominant wind direction throughout the year have a certain protective distance.
Eliminate particulate matter, harmful air, bacteria and other pollutants in the air in a certain space, control indoor temperature, cleanliness, indoor pressure, wind speed and airflow distribution, noise, vibration, lighting and static electricity within a certain demand range, and provide specially designed rooms.
That is, no matter how the outside air conditions change, the room can maintain the original cleanliness, temperature, humidity and pressure requirements.
Similar to diffusion, when the filter material is electrostatic (electret material), the longer the dust stays in the filter material, the greater the possibility of being adsorbed by the material. Changing the wind speed will significantly change the filtration efficiency of electrostatic materials. If you know that there is static electricity on the material, you should try to reduce the amount of air passing through each filter when designing the air conditioning system.
According to the traditional theory, when the wind speed decreases, the probability of collision between dust and fiber decreases, and the filtration efficiency decreases accordingly. But in practice, this effect is not obvious, because the lower the wind speed, the smaller the rebound force of fiber to dust, and the easier it is for dust to get stuck.