Cleanrooms and equipment

What is the role of the thick concrete floor with a grid of holes (waffle slab) used in fab cleanrooms?

  1. ATo suppress vibration with high stiffness while letting air flow under the floor through the holes
  2. BTo store rainwater
  3. CTo lighten the floor and cut construction cost
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Answer: A. To suppress vibration with high stiffness while letting air flow under the floor through the holes

A waffle slab is a thick concrete floor reinforced with grid-like beams and pierced with many holes that serve as passages for downflow air to the space below. At the same time, its high stiffness suppresses vibration harmful to precision tools such as exposure systems. Grating panels are placed over the holes so people can walk on them.

  • A. Correct. It combines stiffness with a path for air.
  • B. It is not a facility for storing rainwater.
  • C. It is a heavy, stiff structure for suppressing vibration.
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More Cleanrooms and equipment questions

  1. In precision facilities such as fabs, which metric grades allowable floor vibration levels as vibration velocity per frequency band?
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  4. What is the main reason yellow lighting is used in lithography areas?
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