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Rick Grout, Mechanical Department Coordinator, Asia with IDC, will be discussing life science and microelectronics cleanroom design practices at CleanRooms Asia 2001. CleanRooms.com recently caught up with Rick to find out what attendees of his session can expect.
CleanRooms.com: What are the main points you plan to address in your presentation at CleanRooms Asia 2001?
Rick Grout: The subject matter of this presentation consists of a comparison of cleanroom design practices as they apply to the microelectronics and to the life-sciences industries. We will review such topics as design criteria, standards and regulatory requirements, cleanroom building materials, minienvironments and isolation barriers, applications of CFD airflow modeling, and cleanroom certification and validation.
CR: What would you like attendees of the presentation to walk away with?
RG: I want to emphasize the similarities rather than the differences between the two industries. New products are in various stages of development or production that utilize technologies borrowed from both industries — technologies which are usually thought of as unique to one industry or the other. As these technologies continue to merge, cleanroom planners must in similar fashion consider merging some of the design and construction practices used by the two industries.
CR: What have been the biggest changes and/or advances in the area of cleanroom construction over the last 15 years?
RG: In the microelectronics industry, we have had to continually adapt to ever-diminishing feature sizes. The need to supply cleaner air, water, gases and chemicals continues to be of paramount importance. We’ve reached the limits of what we can do with air filtration, so the only way we can further reduce particle counts is to increase the cleanliness of the air that enters the filtration device. That means we have to pay stricter attention to what happens over the entire path the recirculated air follows. Meanwhile, more and more fab operators are becoming aware of the need to do something about airborne molecular contamination (AMC). We’ve had to revise our thinking when it comes to the selection of construction materials since just about everything offgases to some extent.
In a lot of ways, life sciences cleanrooms resemble cleanrooms that were commonly built for the manufacture of microelectronics products 15 years ago. That’s not to take anything away from the industry. It?s just that we have different issues to deal with, as well as regulatory requirements which need to be satisfied.
CR: Talk a little about the evolution of the clean minienvironment processing enclosure. What has contributed to its rise in popularity? What are the benefits of, and downsides to, minienvironments?
RG: The design decisions which result in today’s super-clean microelectronics fabs are driven primarily by economics. If owners of these facilities could successfully manufacture their product in a warehouse environment they would. This is impractical of course, so the cleanrooms have gotten more and more expensive as the products built in them have gotten more sophisticated. The minienvironment concept is a response to these increasing costs. The objective is to limit the super-clean environment only to where it is absolutely needed. That means the general cleanroom environment can be downgraded. We still haven’t reached the “warehouse” stage because, as I said before, we still have to pay attention to the quality of the air on the house side of the minienvironment filters. AMC is just as big a problem, too.
Minienvironments definitely save money on cleanroom costs. However, more sophisticated material handling systems are needed to make minienvironments work. The cost of these systems typically doesn’t show up in the building cost — it comes out of the AMHS and tool budgets instead. But as the industry migrates to 300 mm, automation is no longer optional and you have to spend the money anyway.
CR: What are some of the most common “killer defects” that can sabotage electronics, pharmaceutical and biotechnical cleanroom environments?
RG: We still worry about particles in the microelectronics environment. Regardless of what they are made of, particles can interfere with the manufacturing process in a number of ways that will render a device unusable. I mentioned AMC before. There are certain molecules that react chemically with production materials and processes in a such way as to limit how small a device you can build.
In the life sciences field, I think the two biggest concerns are cross-contamination in facilities where multiple products are being manufactured simultaneously, and contamination by viable organisms. In either case, the human consequences can be quite serious.