Low Cost Automation Tutorial

#114 Clean Room Compatible LCA - 5: Materials for Clean Room LCA - 2

Category : Clean room technology

April20, 2012

Materials selection for clean room LCA follows the "3 principles of cleanliness". Especially, following two countermeasures are of the importance.

* Do not generate contamination.
* Do not allow contamination to accumulate.

Next table explains the relationship of "3 principles of cleanliness" and LCA mechanical system materials.

3 principles of cleanliness

LCA mechanical system materials

Explanation

Do not bring in contamination
↓

Countermeasures during equipment load in

*	Not closely related to structural materials
*	Suppression of bring in contamination during load in is important

a）	Cleaning before the equipment is loaded into clean rooms (use water cleaning, etc.)
b）	Equalize equipment and clean room temperatures to avoid water condensation.

Do not generate contamination
↓

Do not generate rusts, abrasion dusts, gases

a）	Corrosion resistant metals, Surface treated materials
b）	Obtain corrosion resistance by surface treatments
c）	Use of electro-passivated products
d）	Do not use general construction materials such as wood, paper, concrete, etc.

e）	Use low evaporative greases
f）	Use wear resistant materials

a）	Prevent rusts by uses of stainless steel, aluminum, and surface treated materials.
b）	Plating (nickel, Reydent, etc.), surface coatings
c）	Select low out-gassing components for vacuum chamber and etc.
d）	Generates particulates in exposed states. Aging variations exist
e）	Use low evaporative greases for sliding components
f）	Select materials and bearings of low particulate nature

Do not allow contamination to accumulate
↓

Do not let statically charged

Do not let air flow congested

a）	Electrically conductive materials
b）	Electrically conductive surface treatments
b）	Punch perforated SUS sheet steel

a）	Use electrically conductive materials to avoid static charging, and ensure grounding.
b）	Use anti-static surface treatments for plastics
c）	Use sheet metals that do not congest air flow