How is cleanliness graded and what is the standard?

Cleanliness is graded according to the number of particles in the air, mainly harmful substances such as floating dust and bacteria. In addition, according to different process requirements, temperature and humidity, pressure and noise will be controlled to a certain extent.

Cleanliness classification is to detect particles in a certain spatial range. The most commonly used is the American federal 209E standard, which detects 1 cubic foot (ft? )。 International ISO 14644 detection 1 m3 (m? )。 The particle size is 0. 1-5μm, and generally 0.5μm is taken as the reference value.

For example,/kloc-class 0/00 clean room, 1 cubic foot (ft? 0.5μm has 100 particles, a thousand particles are 1000 and ten thousand particles are 10000, which is very easy to understand. Therefore, the smaller the value, the higher the cleanliness level.

American federal 209E and international ISO grade comparison table.