CLEAN ROOM

 The CLEANROOM means the room which is tightly closed. There is the control on the substances or PARTICLES in the air including the control on the temperature, humidity, noise, light, and pressure of the air inside the room for the room to become the clean room following the STANDARD and CLASS. Generally, the sizes of particles will be referred in micron (m) and 1 m = 1x10^-6. In order to get clearer vision, please see Figure 1 which is written following the scale. From the figure, the particle of 1 micron is seen compared to the average size of human’s hair in the particles of 59 microns allowing the smallest particles to spread in the air in the size of 0.5 micron.

4 principles of Clean Room

1. Prevent the particles and substances to enter the clean room
    - Filter the air penetrating the Clean Room by HEPA filter
    - Maintain the positive pressure inside the Clean Room
    - The staffs should pass the air shower before passing into the Clean Room.
    - The materials and parts must be cleaned before entering Clean Room)
2. Prevent the generation of dust particles inside the Clean Room
    - The staffs must wear the clean room garment during the operation.
    - The staffs should not make quick move unless necessary during the operation.
    - The materials of floor, wall, and ceiling should not be the ones generating dusts.
3. Prevent the accumulation of dusts on the wall and surface of materials and machines.
    - Define the standards in cleaning the Clean Room
    - The floor, wall, and the door inside the Clean Room should be made from the materials that are easily to be cleaned.
4. Remove the dust particles inside the room
    - The air change of the clean room should be suitable for making the room clean as required by the class.
    - The air suction system should be installed in various places where there is much spreading of dust particles.

Mod of Clean Room
1. A s-built is the vacant Clean Room without the installation of machines and there is no operator.
2. At-rest is the Clean Room installed with the machine and has been operated but there is no operator.
3. Operational is the Clean Room with the operation of machines and the operators as usual.