1、INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Contamination Control Division Reco ended Practice 04.3 IEST-RP-C04.3 Evaluating Wiping Materials Used in Cleanroms and Other Controled Environments INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Arlington Place One 2340 S. Arlington Heights Roa
2、d, Suite 10 Arlington Heights, IL 6005-4516 Phone: (847) 981-010 Fax: (847) 981-4130 E-mail: iestiest.org Web: ww.iest.org 2 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C04.3 IEST-RP-C04.3 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Copyrighted material 3 T
3、his Recomended Practice is published by the INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY to advance the technical and enginering sciences. Its use is entirely voluntary, and determination of its aplicability and suitability for any particular use is solely the responsibility of the user. This
4、Recomended Practice was prepared by and is under the jurisdiction of Working Group 04 of the IEST Con-tamination Control Division. Copyright 204 by the INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY First printing, August 204 ISBN 978-1-87862-98-4 PROPOSAL FOR IMPROVEMENT: The Working Groups of
5、the INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY are continualy working on improvements to their Recomended Practices and Reference Documents. Sugestions from those who use these documents are welcome. If you have a sugestion regarding this document, please use the online Proposal for Improvem
6、ent form found on the IEST website at ww.iest.org/proposal/form.html. INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Arlington Place One 2340 S. Arlington Heights Road, Suite 10 Arlington Heights, IL 6005-4516 Phone: (847) 981-010 Fax: (847) 981-4130 E-mail: iestiest.org Web: ww.iest.org 4 Copyr
7、ighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C04.3 IEST-RP-C04.3 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Copyrighted material 5 Evaluating Wiping Materials Used in Cleanrooms and Other Controlled Environments IEST-RP-C004.3 CONTENTS SECTION 1 SCOPE AND LIMITA
8、TIONS.7 2 REFERENCES7 3 TERMS AND EFINITIONS.8 4 BACKGROUND AND PURPOSE.8 5 RECOMENDED LABORATORY PRACTICES9 6 TESTS FOR PARTICLES.10 7 TESTS FOR EXTRACTABLE MATER18 8 TEST FOR SORBENCY CAPACITY AND SORBENCY RATE.2 9 METHOD FOR QUANTIFYING BIOBURDEN ON CONSUMABLES.25 10 TEST FOR STATIC26 FIGURE 1 PA
9、RTICLE SIZE AND ENUMERATION TECHNIQUE13 2 16 FIELDS17 3 32 FIELDS17 TABLE 1 PRECISION AND BIAS TEST RESULTS (10 REPLICATIONS)25 APPENDIX A BIBLIOGRAPHY27 6 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C04.3 IEST-RP-C04.3 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECH
10、NOLOGY Copyrighted material 7 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Contamination Control Division Recommended Practice 004.3 Evaluating Wiping Materials Used in Cleanrooms and Other Controlled Environments IEST-RP-C004.3 1 SCOPE AND LIMITATIONS 1.1 Scope This Recomended Practice (RP) d
11、escribes methods for testing wipers used in cleanroms and other con-troled environments for characteristics related to both cleanlines and function. 1.2 Limitations No recomendations are made for the construction, packaging, or laundering of wipers, or for the deter-mination of such physical charact
12、eristics as strength or resistance to abrasion. 2 REFERENCES The folowing documents are incorporated into this RP to the extent specified herein. Users should aply the most recent editions of the references. 2.1 ANSI ANSI/AMI/ISO 1737-1: Sterilization of medical devices microbiological methods Part
13、1: Estima-tion of population of microrganisms on products 2.2 American Society for Testing and Materials (ASTM) ASTM D193-9e1: Standard Specification for Rea-gent Water ASTM E548-94: Standard Guide for General Criteria Used for Evaluating Laboratory Competence ASTM E2090-0: Standard Test Method for
14、Size-Diferentiated Counting of Particles and Fibers Re-leased from Clean Rom Wipers Using Optical and Scaning Electron Microscopy ASTM F25-68(199): Standard Test Method for Sizing and Counting Airborne Particulate Contamination in Clean Roms and Other Dust-Controled Areas De-signed for Electronic an
15、d Similar Aplications ASTM F31-97(202): Standard Practice for Proc-esing Aerospace Liquid Samples for Particulate Contamination Analysis Using Membrane Filters ASTM F312-97(203): Standard Test Methods for Microscopicaly Sizing and Counting Particles from Aerospace Fluids on Membrane Filters 2.3 ESD
16、ESD STM1.1-201: Surface Resistance Measure-ment of Static Disipative Planar Materials 2.4 Institute of Environmental Sciences and Technology (IEST) IEST-RP-C013-86T: Equipment Calibration or Validation Procedures IEST-RP-C02.1: Electrostatic Charge in Clean-roms and Other Controled Environments 2.5
17、International Organization for Standardization (ISO) ISO 1464-1: Cleanroms and asociated controled environmentsPart 1: Clasification of air cleanlines 8 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C04.3 2.6 SEMI SEMI C10-098: Guide for Determination of Method Dete
18、ction Limits 2.7 Other References 1. Automotive Industry Action Group. 202. Meas-urement Systems Analysis. 3rd Ed. Detroit, I: AIAG. 2. Wheler, D.W. and R.W. Lyday. 198. Evaluating the Measurement Proces. 2nd Ed. Knoxvile, TN: SPC Pres Inc. 3. Rudisil, J.F. and E.E. Burch. 199. Quality Man-agement Q
19、uality Asociates of Clemson. 2.8 Sources and Addresses ANSI American National Standards Institute 25 West 43rd Stret New York, NY 1036, USA Phone: 212-642-490 Fax: 212-398-023 Web: ww.ansi.org ASTM American Society for Testing and Materials 10 Bar Harbor Drive West Conshohocken, PA 19428-2959, USA P
20、hone: 610-832-9585 Fax: 610-832-955 Web: ww.astm.org ESDA Electrostatic Discharge Asociation 790 Turin Road, Bldg. 3 Rome, New York 1340-2069, USA Phone: 315-39-6937 Fax: 315-39-6793 Web: ww.esda.org IEST Institute of Environmental Services and Technology 2340 S. Arlington Heights Road, Suite 10 Arl
21、ington Heights, IL 6005-4516, USA Phone: 847-981-010 Fax: 847-981-4130 Web: ww.iest.org ISO In the U.S., documents may be ordered from: IEST 2340 S. Arlington Heights Road, Suite 10 Arlington Heights, IL 6005-4516 USA ww.iest.org Outside the US: Documents available from representative ISO member bod
22、y organization SEMI Semiconductor Equipment and Materials International 1401 K Stret NW, Suite 601 Washington DC 2005, USA Phone: 202-289-040 Fax: 202-289-041 Web: ww.semi.org 3 TERMS AND EFINITIONS generated particles Particles that are not already present on the surface of a wiper, but that are ge
23、nerated in response to impart-ing mechanical energy to the wiper. particle A solid or liquid object that, as a general rule, meas-ures from 0.01 m to 100 m in size. releasable particles Particles that are already present on the surface of a wiper and are readily releasable from it by weting it with
24、a liquid, but without imparting mechanical en-ergy to the wiper. sorption A physical or chemical mechanism whereby a fluid is taken up by a solid surface (as distinct from adsorp-tion, which ocurs within pores and capilaries as wel as on surfaces). 4 BACKGROUND AND PURPOSE Tests for wiping materials
25、 can be divided into two broad categories, one concerned with function, the other with contamination. The most important functional characteristic of wipers may be their ability to sorb liquids. Two separate char-acteristics related to sorbency are relevant: capacity (how much liquid a wiper can sor
26、b) and rate (how fast the wiper can sorb the liquid). Tests for these distinct characteristics are described in section 8. Tests for contamination (or cleanlines) can be listed almost without end. However, the consensus in high-technology industries is that particles, non-speciated extractable mater
27、, and individual ionic constituents are the most important contaminants. Section 5 describes recomended laboratory prac-tices that should be folowed when testing wiping products. These practices are designed to promote the IEST-RP-C04.3 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Copyrighted
28、material 9 quality and validity of al laboratory measurements using standard practices and procedures. Section 6 describes tests for enumeration of particles releasable from a wiper. The number of particles that can be released from a wiper is maximized when the wiper is imersed in a liquid that wil
29、 properly wet the fiber surfaces. Thus, testing wipers in a weted condition is the most eficient way to enumerate these particles. Two methods of sample preparation and two methods of enumeration are described. Section 7 describes tests for the quantitative analysis of unspecified mater extractable
30、from wipers. Two procedures for extracting and quantifying general extractable mater are described in section 7.1, one a short-term test, the other an exhaustive extraction. Section 7.2 provides guidelines for use when the quantitative analysis of specific constituents is re-quired. Non-speciated ex
31、tractable mater is covered in section 7.1, while organic compounds and inor-ganic constituents are described in sections 7.2.1 and 7.2.2, respectively. Section 8 describes tests for sorbency capacity and sorbency rate. Section 9 describes test methods for sampling and quantifying bioburden on wiping
32、 products. Sterile aparatus and aseptic techniques are required to per-form tests. This RP does not categorize wipers acording to their suitability for particular aplications. Rather, it ofers rational and germane tests to determine those charac-teristics of wiping materials generaly acknowledged to
33、 be important. The results of these tests permit the quantitative asesment of the merits of wiping mate-rials acording to the mix of properties considered important in relation to their intended use. 5 RECOMENDED LABORATORY PRACTICES In general, recomended laboratory practices are designed to promot
34、e the quality and validity of al laboratory measurements using standard practices and procedures. It is expected that users of IEST-RP-C04 wil folow recomended laboratory practices in the measurement of wiper characteristics. NOTE: This RP does not purport to adres al of the safety problems, if any,
35、 asociated with its use. It is the responsibility of the user to establish apropriate safety and health practices and to de-termine the aplicability of regulatory limitations prior to use. Recomended laboratory practices include: a) System blank Where feasible, a system blank should be performed to
36、ensure the cleanlines of al equipment, aparatus, reagents, and materials asociated with a given meas-urement. In a system blank, the measurement of the analyte (the characteristic to be measured, such as particles, ions, NVR, etc.) is performed, but without the sample. As a general rule, the system
37、blank value should comprise no more than 15% of the test sample value. b) Sampling and analysis The sample taken for analysis should be large enough to produce reasonable acuracy and precision for a given measurement. Where feasible, the sample size should be large enough that the measured value of
38、the analyte is at least twice the detection limit for the measurement (se also section 5f). If that is not pos-sible and the sample measures below the detection limit, then the sample is reported as “below detection limit” (zero indicates no quantity found with a perfect measurement tol, therefore “
39、below detection limit” should be used rather than zero). Also, where feasi-ble, the sample size should be large enough that the test sample value is 7 higher than the system blank (section 5a). At least thre representative samples should be se-cured for analysis from the same production lot. Also, e
40、ach sample should be labeled with date, lot number, and measurement type to provide an audit trail if neded. c) Environment Al sample preparation work on samples and system blanks for particles and ions should be performed in an environment that prevents contamination of the analyte of interest. The
41、 environment may include an ISO Clas 5 at 0.5 m clean hod or cleaner envi-ronment. Test for sorbency, residues, and bioburden shal be conducted in a similar clean environment unles not practical. d) Handling of samples To avoid extraneous contamination, where aplicable, al samples should be handled
42、using pre-cleaned clean-rom gloves (vinyl prefered over latex), twezers, and forceps in an environment described in section 5c. e) Calibration and validation (se also ASTM E548 and IEST-RP-C-013-86T) Laboratories should determine a proper time interval for instrument calibration. Instrument or syste
43、m cali-bration should be made with reference standards. Equipment performance should be verified at least 10 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C04.3 once a year and after any major service of the equip-ment. Laboratories should also set limits within whi
44、ch an analytical instrumentation system or a piece of equipment should operate. f) Detection limits Where feasible, measurement of method detection limits should be performed by using regresion analysis of calibration data. Details are included in SEMI C10-098. Ion determinations are performed using
45、 analytical equipment for which calibration data of each analyte can be obtained. Thus, detection lim-its for each ion type can be established. g) Recovery studies for soluble species In order to develop confidence in the performance of a proposed test method, it is god practice to dose one or more
46、test samples intentionaly with known amounts of the apropriate analyte, then perform a recovery study by measuring and quantifying the analyte using the proposed test method. A high per-centage recovery for a given analyte signifies high confidence in the proposed test method. h) Numerical analysis
47、Where feasible, replicate analysis should be per-formed and mean and deviation reported. A Proces Measurement Index (PMI), also known as a Percent Gage R that is, the ability to distinguish betwen one part or lot and another. This subject is treated in an easily understod maner in references 1 and 3
48、. It is exhaus-tively treated in reference 2. These references show that the statistical eror asociated with the measurement proces stands in the way of discriminatory power. The Percent Gage R if necesary, use a clean glas stiring rod to gently push the wiper under the water so that it sorbs to its
49、 ful capacity. 3) After sorption is complete, grasp two adja-cent corners of the specimen and remove it from the tray. In this way, suspend the specimen at an angle to the horizontal, al-lowing the exces liquid to drip into the tray. The angle should be step enough to facili-tate driping, but not so step that pleating of the wiper ocurs. The wiper should not be stretched or otherwise dimensionaly de-formed as it is driping. After 60 sec, deter-mine the mas of the weted wiper to thre significant figures. 4) Repeat steps 2 and 3 twice, using the same specim
