Something in the air

12/01/2008

Cleanroom operators in life sciences and microelectronics both require compliance to ISO standards for air cleanliness and instrument performance, finding continuous monitoring systems advantageous in the battle against airborne contaminants.

By Bruce Flickinger

Airborne particulate contamination is a quality issue in both the life science and electronics sectors, but there is one overarching difference between their respective needs: Relatively speaking, those in bio/pharma are looking for “rocks in the air,” in the words of one observer.

These “rocks” are particles that could potentially be or transport microbial contaminants, falling into the 0.5 ??m and larger and 5.0 ??m and larger size ranges. Contrast this with the ever-decreasing particle sizes that microelectronics manufacturers must guard against???down to 0.01 ??m and beyond???and it is clear that different dynamics drive decision-making about airborne particle counting in these industries.

Life sciences users are “looking for biological activity, and they use nonviable particle counts to gauge the potential for these particles to be viable, living organisms,” says Amit Nag, product manager with Hach Ultra (Grants Pass, OR). “They are primarily interested in two types of particles, so instrument sensitivity does not need to be as high as it does in microelectronics.”

In semiconductor, flat-panel display, and hard disk storage fabrication, improvement of air quality???that is, a reduction of particulate contamination???can lead to increases in final product yield. The ability to detect smaller and smaller contaminants is a constant for operating cleanroom environments in these industries. “Instrument sensitivity tends to be the single biggest factor driving purchase decisions in this industry,” says Ross Bryant, director of marketing with Particle Measuring Systems (Boulder, CO).

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