IES Issues Two New Contamination Control RPs
By Meredith E. Lawrie
Mount Prospect, IL–The IES recently published two new Recommended Practices (RPs)–“Measuring and Reporting Vibration in Microelectronics Facilities,” and “Cleanroom Operations”–both for use in the contamination control field.
Measuring and Reporting Vibration in Microelectronics (IES–RP-CC024.1) was developed for the electronics industry to help provide needed guidance in dealing with vibration. According to Walter Djordjevic, working group chair and author of the document, vibration statistics currently available in the industry are incomplete. The new RP will provide recommendations on what types of instrumentation are normally used and what sensitivities they should have, how a design criterion should be developed and how to establish minimum thresholds for microelectronics processes.
Specifically, the RP will provide guidance in selecting suitable instrumentation and hardware for use in vibration measurements, establishing sensitive process tool vibration thresholds, conducting vibration measurements on sites and facilities, and reporting results of vibration measurements in a uniform and consistent format.
“The industry has always been aware of vibration–we`ve certainly spent a lot of money over the last 10 years trying to design facilities around it,” says Djordjevic. “But the standard quantifies, to an extent, some of the information that`s jumbled around out there so that we can all be on the same wavelength, know how we should conduct our measurements and how we should present our data.”
The document also provides terms and definitions, and a vibration measurement and data set-up list.
The second new IES standard, Cleanroom Operations (IES-RP-CC026.1), provides guidance for maintaining the integrity of the cleanroom during ancillary operations, which include: preparation of supplies and materials; modification of the facility; and installation and repair of equipment. Much like RP-CC024.1, the standard is a straight-forward description of procedures for verifying the cleanliness of equipment, and includes different methods for verifying cleanliness such as: The Continuous Flowing Duct Method, in which the apparatus to be evaluated is placed in a duct passing ULPA-filtered air at a known flow rate; The Reservoir Method, in which the equipment whose particle emission rate is to be measured is placed in a closed chamber so that all particles emitted are trapped within the reservoir; and The Contact Plate Method, which is used to detect microorganisms that may be present on flat surfaces in relatively low numbers. Anne Marie Dixon, committee chair, adds that the RP also contains information about the admittance of items into the cleanroom or controlled environment, which she feels is very important because contamination can be admitted into a manufacturing area if the procedure isn`t defined and controlled.
The IES is quick to point out that the new contamination control RPs are becoming more and more applicable to other fields, such as the pharmaceutical and biological research areas, and that they should help to steer new users in the right direction.
For more information about IES RP CC024.1 or CC026.1, contact the IES at 940 East Northwest Highway, Mount Prospect, IL 60056, (708) 255-1561. n