Questions concerning IEST-RP-CC031.2 answered
05/01/2008
The revision expands the list of materials of concern and provides more examples of sample preparation to help eliminate industry confusion
By Jim Ohlsen, Chair of IEST Working Group CC031
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In February 2008, IEST published the latest revision of IEST-RP-CC031.2: Method for Characterizing Outgassed Organic Compounds from Cleanroom Materials and Components. Five years after the original IEST-RP-CC031.1 version was published, this revision enables the user to scrutinize a greater number of cleanroom materials, components of construction, and polymers that can outgas organic compounds of concern. Experts in contamination control for aerospace, data storage, and microelectronics used their training as engineers, scientists, and educators to help contribute to the revision process. A seminar will be offered at ESTECH 2008 and should be of interest for industry representatives from numerous related fields.
What are the most significant changes from the previous edition?
Sub-section 4.1, “Materials of Interest,” has been expanded to include more than fifty materials, components of construction, and polymers that may outgas organic compounds of concern in cleanrooms or other controlled environments.
Sub-section 4.2, “Organic Compounds of Concern,” now references ISO 14644-8:2006(E), Annex B, thus greatly expanding the list of contaminating chemicals that can be of concern to a microelectronics product or process.
Sub-section 5.1, “Test Material and Sample Preparation,” has been expanded to include more examples of sample preparation such as a solid to solid transfer method; cure times for two-part mixtures, coatings, paints, sealants, and caulks; and sample preparations for homogeneous and non-homogeneous materials.
Finally, sub-section 5.6, “Extensions of Outgas Testing Beyond this RP,” has been added to briefly address testing of the outgassing of a large part, assembly, or complete system that may be in operation.
How do these changes improve the RP and/or make it easier for the user to apply?
These changes improve the RP by enabling the user to scrutinize a greater number of materials, components of construction, and polymers that can outgas organic compounds of concern. Similarly, a list of the number of organic compounds of concern has increased. In addition, more examples of sample preparation are described. Finally, a brief explanation is given of how the test method of this RP can be extended to test the outgassing of a large part, assembly, or complete system that may be in operation.
What leading-edge or innovative technology does the RP incorporate?
The RP incorporates thermal desorption gas chromatography mass spectrometry (TD-GC-MS). Having access to this technology is essential to carrying out the test method described in this RP. Companies that do not have this capability in-house can utilize contract laboratories; thus the test method of this RP is accessible to anyone.
Does the RP help clarify methods or practices that are a source of industry controversy or confusion?
The RP describes a test method appropriate for semiquantitative determination and qualitative characterization of organic compounds outgassed from materials or components exposed to air in cleanrooms or other controlled environments. This RP specifies four outgassing temperatures–50??C (122??F), 75??C (167??F), 100??C (212??F), and 150??C (302??F)–to baseline cleanroom materials and components. Different temperatures introduce different levels of outgassing airborne molecular contaminants (AMCs). The recognition that different temperatures can be used to characterize different outgassing conditions that cleanroom materials and components may be subjected to is as significant today as in 2003 when the RP was first published. The method in this RP is believed to be the most appropriate analysis to provide chemical information for a large range of organic compounds that may outgas under ambient or higher temperature conditions.
What tools does the RP provide (e.g., worksheets, resources, etc.) to help users implement the document?
Section 6 of the RP, “Reporting,” lists the elements necessary to provide information about material identification, sample description, instrument/system information, compounds detected, and GC-MS chromatograms.
Who is the audience–what users will benefit from the information?
The users who will most benefit from the information include engineers, scientists, educators, and other experts in contamination control or contamination-sensitive industries such as aerospace, data storage, and microelectronics. Experts engaged in cleanroom construction, along with providers of cleanroom supplies and equipment, will also find the information relevant.
Working Group CC031, Outgassing Performance Criteria for Cleanroom Materials, will continue to meet twice a year, at ESTECH and the Fall Conference, over the next three years to address revisions to this recommended practice as well as additions that will enhance its usefulness to all professionals engaged in contamination control.
Jim Ohlsen is director of the Materials Characterization Group at Entegris, Inc., where he is responsible for three global materials technology laboratories and one technology characterization laboratory. He has a PhD in chemistry from Texas A&M University. As an active member of IEST, Ohlsen represents Entegris, Inc. as a corporate sponsor, and serves as director of Standards and Practices Committee 3: Procedural and as a reviewer for the editorial board of the Journal of the IEST. He is the 2007 recipient of the IEST Monroe Seligman Award, has presented three tutorials on IEST-RP-CC031.1, and serves as chair of WG-CC031.
About IEST
Founded in 1953, IEST is an international technical society of engineers, scientists, and educators that serves its members and the industries they represent (simulating, testing, controlling, and teaching the environments of earth and space) through education and the development of recommended practices and standards. IEST is an ANSI-accredited standards-developing organization; secretariat of ISO/TC 209 Cleanrooms and associated controlled environments; administrator of the ANSI-accredited U.S. TAG to ISO/TC 209; administrator of the ANSI-accredited U.S. TAG to ISO/TC 142 Cleaning equipment for air and other gases; and a founding member of the ANSI-accredited U.S. TAG to ISO/TC 229 Nanotechnologies.