No 'absolutes' for cleanliness in ISO 5 design

摘要

Not too long ago, I sat down with a prominent researcher in advanced materials to discuss his upcoming cleanroom requirements. He was currently working in an ISO 6 or Class 1000 laboratory. I asked him to describe the critical nature of the contamination control required for his research. His response was, "I need Class 100." All right, but what about the type, size, and concentration of "killer particles" that would negatively affect his work? Again, his response was, "I need Class 100." It took quite a while to convince him that cleanroom design does not begin with designing to the next higher level of cleanliness, but that understanding the contamination characteristics detrimental to the process leads to determining the appropriate level of cleanroom classification. We finally concluded with a sound understanding of his needs.