IEST RP-CC022 2-2004 ELECTROSTATIC CHARGE IN CLEANROOMS AND OTHER CONTROLLED ENVIRONMENTS.pdf

1、INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Contamination Control Division Reco ended Practice 02.2 IEST-RP-C02.2 Electrostatic Charge in Cleanroms and Other Controled Environments INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Arlington Place One 2340 S. Arlington Heights Road, Suite 10

2、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-C02.2 IEST-RP-C02.2 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Copyrighted material 3 This Recomend

3、ed Practice is published by the INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY to advance contamination control and the technical and enginering sciences. Its use is entirely voluntary, and determi-nation of its aplicability and suitability for any particular use is solely the responsibility of

4、the user. This Recomended Practice was prepared by and is under the jurisdiction of Working Group 02 of the IEST Con-tamination Control Division. Copyright 204 by the INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Second printing, January 204 ISBN 978-1-87862-8-5 PROPOSAL FOR IMPROVEMENT: The Wo

5、rking Groups of the INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY are continualy working on improvements to their Recomended Practices and Reference Docu-ments. Sugestions from those who use these documents are welcome. If you have a sugestion regarding this document, please use the online Prop

6、osal for Improvement 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

7、.iest.org 4 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C02.2 IEST-RP-C02.2 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Copyrighted material 5 Electrostatic Charge in Cleanrooms and Other Controlled Environments IEST-RP-C022.2 CONTENTS SECTION 1 SCOPE AND L

8、IMITATIONS.7 2 REFERENCES7 3 TERMS AND EFINITIONS.9 4 BACKGROUND AND PURPOSE1 5 ELECTROSTATIC CHARGE CONTROL SYSTEMS1 6 EQUIPMENT AND PROCEDURES.13 TABLE 1 TYPICAL SOURCES OF ELECTROSTATIC CHARGE IN CONTROLED ENVIRONMENTS12 2 TYPICAL ELECTROSTATIC VOLTAGE LEVELS GENERATED BY PRODUCTION PERSONEL12 3

9、LIMITS ON STATIC DECAY TIME16 4 RELEVANT STANDARDS FOR EVALUATING CHARACTERISTICS OF PLASTIC PACKAGING AND HANDLING MATERIALS.18 5 STANDARD TEST METHODS RELEVANT TO THE EVALUATION OF CONTAMINATION PROPERTIES OF ATERIALS2 6 EXAMPLE OF A TRAINING LOG.23 FIGURE 1 ESD LABELS AND AWARENES SIGNS.2 A1(A) T

10、EST POSITIONS (TP) FOR TABLETOP BLOWERS.25 A1(B) TEST LOCATIONS FOR OVERHEAD; TOP VIEW.25 A1(C) TEST LOCATION FOR OVERHEAD BLOWERS; FRONT VIEW.25 A2 TEST PLATE POSITION FOR BLOW-OF GUN.26 6 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C02.2 A3 TEST POSITIONS FOR UN

11、IDIRECTIONAL-FLOW BENCHES A3(A) END VIEW, VERTICAL FLOW A3(B) END VIE, HORIZONTAL FLOW.26 A4 TEST POSITIONS FOR ROM IONIZATION; EXAMPLE FOR AC GRIDS (LES THAN 10% COVERAGE) AND PULSED OR STEADY-STATE DC BARS; TP1 IS DIRECTLY UNDER THE GRID OR BAR, WHILE TP2 IS CENTERED BETWEN IONIZERS.27 A5 TEST POS

12、ITIONS FOR ROM IONIZATION; EXAMPLE FOR SINGLE- POLARITY EMITER-TYPE DC IONIZATION SYSTEM; THRE MEASUREENTS ARE REQUIRED.27 A6 TEST POSITIONS FOR ROM IONIZATION; EXAMPLE FOR DUAL DC LINE IONIZATION SYSTE; THRE MEASUREENTS ARE REQUIRED.27 A7 TEST POSITIONS FOR ROM IONIZATION; EXAMPLE FOR PULSED C EMIT

13、ER IONIZATION SYSTEM; TWO MEASUREENTS ARE REQUIRED.27 APPENDIX A AIR IONIZER TESTS.24 B BIBLIOGRAPHY28 IEST-RP-C02.2 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Copyrighted material 7 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Contamination Control Division Recommended Practice 022.2

14、Electrostatic Charge in Cleanrooms and Other Controlled Environments IEST-RP-C022.2 1 SCOPE AND LIMITATIONS 1.1 Scope This Recomended Practice (RP) discuses methods for specifying and evaluating the efectivenes of techniques for controling electrostatic charge. Proper control of electrostatic charge

15、 may reduce particulate contamination on surfaces and the likelihod of elec-trostatic discharge. This document, which describes typical control systems and their aplications, also lists methods of testing and measurement of charge generation, charge neutralization, resistivity of sur-faces and mater

16、ials, and static field atenuation. 1.2 Limitations This RP excludes specific evaluation and qualifica-tion related to the protection of ordnance, flama-ble materials, and explosives. This RP does not prescribe design or control limits; quality acep-tance standards; proces isues; or health, safety, a

17、nd environmental isues and practices outside of contamination control isues. Users should establish their own quality standards. 2 REFERENCES 2.1 Documents 2.1.1 ASTM D257-78 Standard Test Methods for DC Resistance or Conductance of Insulating Materials E595-93 Standard Test Method for Total Mas Los

18、 and Colected Volatile Condensable Materials from Outgasing in a Vacum Environment E1235-01 Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentaly Controled Areas for Spacecraft F31 Test Method for Nonvolatile Residue Extract from Aerospace Components (Usin

19、g Flash Evaporator) 2.1.2 EIA EIA-583 Packaging Material Standards for Moisture Sensitive Items 2.1.3 ESD ESD ADV1.0-194 for Electrostatic Discharge Termi-nology Glosary 8 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C02.2 ESD-STM5.1-201 for Electrostatic Discharge

20、 Sensi-tivity TestingHuman Body Model (HBM) Component Level ESD-STM7.1-201 for Protection of Electrostatic Discharge Susceptible ItemsResistive Charac-terization of Flor Materials 2.1.4 Federal Test Method Standard FTMS 101C Method 4046.1 Electrostatic Properties of Materials 2.1.5 FDA 21CFR1020.40

21、Title 21, Vol. 8, Part 1020 Perform-ance Standards for Ionizing Radiation Emiting Products, Sec.1020.40 Cabinet X-Ray Systems FDCA, Chapter V, Subchapter C Electronic Product Radiation Control, Sections 531-542 2.1.6 IDEMA Document No. M7-98 Organic Contamination as Nonvolatile Residue (NVR) Documen

22、t No. M9-98 Particulate Contamination Test Methods for Hard Disk Drive Components Document No. M1-9 General Outgas Test Proce-dure by Dynamic Headspace Analysis Document No. M12-9 Measurement of Extract-able/Leachable Cation Contamination Levels on Drive Components by Ion Chromatography 2.1.7 IEST I

23、EST-RP-C04: Evaluating Wiping Materials Used in Cleanroms and Other Controled Environ-ments IEST-RP-C05: Gloves and Finger Cots Used in Cleanroms and Other Controled Environments IEST-RP-C012: Considerations in Cleanrom Design IEST-RP-C018: Cleanrom HousekepingOper-ating and Monitoring Procedures IE

24、ST-RP-C020: Substrates and Forms for Docu-mentation in Cleanroms IEST-RP-C031: Method for Characterizing Out-gased Organic Compounds from Cleanrom Materials and Components IEST-STD-C1246D: Product Cleanlines Levels and Contamination Control Program 2.1.8 ISO ISO 14952: 1ISO 1464: Cleanroms and asoci

25、ated controled environments 1To be published 2.1.9 Military standards MIL-PRF-81705D Performance Specification: Bar-rier Materials, Flexible, Electrostatic Protective, Heat-sealable MIL-STD-1686C Electrostatic Discharge Control Program for Protection of Electrical and Elec-tronic Parts, Asemblies, a

26、nd Equipment (Ex-cluding Electricaly Initiated Explosive Devices) 2.1.10 NASA NASA KSC-C-123H Specification for Surface Cleanli-nes of Fluid Systems NASA MA-1985-79 Standard test method for evalu-ating triboelectric charge generation and decay 2.1.1 NFPA NFPA 9: Standard for Health Care Facilities 2

27、.1.12 NRC 10CFR20 Title 10, Part 20 Standards for Protection Against Radiation 2.1.13 SAE ARP598 Aerospace Microscopic Sizing and Counting of Particulate Contamination for Fluid Power Systems 2.2 Sources and addreses ASTM International 10 Bar Harbor Drive P.O. Box C70 West Conshohocken, Pensylvania

28、19428-2959 USA ww.astm.org EIA Electronic Industries Aliance 250 Wilson Blvd. Arlington, VA 2201 ww.eia.org ESDA ESD Asociation 790 Turin Bldg. 3, Suite 2 Rome, New York 1340-2069 USA ww.esda.org FDA U.S. Fod and Drug Administration 560 Fischers lane Rockvile, Maryland 20857 USA ww.fda.gov IEST Inst

29、itute of Environmental Sciences and Technology 2340 S. Arlington Heights Road, Suite 10 Arlington Heights, IL 6005-4516 ww.iest.org IEST-RP-C02.2 INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY Copyrighted material 9 ISO In U.S., documents may be ordered from: IEST 2340 S. Arlington Heights Road,

30、 Suite 10 Arlington Heights, IL 6005-4516 USA ww.iest.org Outside U.S.: Documents available from representa-tive ISO member body organization JSA (JIS) Japanese Standards Asociation 1-24, Akasaka, 4 Chome, Minatoka Tokyo, 107, Japan ww.jsa.or.jp Military standards (MIL) Standardization Document Orde

31、r Desk 70 Robins Avenue Bldg #4, Section D Philadelphia, Pensylvania 1911-5094 USA NASA-KSC National Aeronautics and Space Administration Kenedy Space Center Manufacturers Materials Analysis Branch Ground Systems Directorate Kenedy Space Center, Florida USA ww.nasa.gov NFPA National Fire Protection

32、Asociation Batery March Park Quincy, asachusets 0269 USA ww.nfpa.org NPFC The Naval Publications and Forms Center 5801 Tabor Avenue Philadelphia, Pensylvania 19120 USA NRC U.S. Nuclear Regulatory Comision Atention: Director, Division of Document Control P-130A Washington, D.C. 2055 USA ww.nrc.gov NT

33、IS National Technical Information Service U.S. Department of Comerce 5285 Port Royal Road Springfield, Virginia 2161 USA ww.ntis.gov OSHA Ocupational Safety and Health Administration U.S. Department of Labor 20 Constitution Avenue, NW Washington, D.C. 20210 USA ww.osha.gov SAE SAE International 40 C

34、omonwealth Drive Warendale, PA 15096-001 USA ww.sae.org SEMI Semiconductor Equipment and Materials International 805 East Midlefield Road Mountain View, CA 94043 ww.semi.org 3 TERMS AND EFINITIONS This section includes terms and definitions from Electrostatic Discharge Asociation. air ions molecular

35、 clusters of about ten molecules (water, impurities, etc.) bound by polarization forces to a singly charged oxygen or nitrogen molecule conductive materials for the purpose of controling static charge, materials having a surface resistivity of les than 105ohms/ square or a volume resistivity of les

36、than 104ohm-cm decay time time required for an electrostatic potential to be re-duced to a given percentage (usualy 10%) of its ini-tial value discharge time time necesary for a voltage (due to an electrostatic charge) to decay from an initial value to some arbi-trarily chosen final value; used for

37、testing ionizers electrostatic charge control (ESC) system of instalations, materials, acesories, and procedures that maintains electrostatic efects below the tolerance limits for a given product or proces electrostatic damage damage to a product caused by static electricity re-sulting from either (

38、1) discharge from a charged con-ductor, (2) field induction, or (3) self discharge NOTE: Damage thresholds for each of these causes of failure may difer from product to product. electrostatic discharge (ESD) transfer of electrostatic charge betwen bodies at dif-ferent electrostatic potentials, cause

39、d by relatively close proximity or direct contact electrostatic discharge control (ESDC) limitation or elimination of electrostatic charge transfer 10 Copyrighted material INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY IEST-RP-C02.2 electrostatic field a) region surounding a charged object withi

40、n which another charge wil experience a force b) voltage gradient betwen an electrostaticaly charged surface and another surface at a diferent electrostatic potential electrostatic field detector device used to determine the presence of electrostatic charge electrostatic potential potential diferenc

41、e betwen a point and an agred-upon reference point ESD-protective material materials capable of disipating, avoiding, or shield-ing electrostatic ocurences; generaly clasified by resistivity as either conductive or static-disipative ground conducting conection to the earth, or to some other conducti

42、ng body that serves in place of the earth ground lead conductive cabling or a similar device for use in a wrist strap or other grounding system; in a wrist strap system, the lead conects the cuf and ground Example: In a fot strap system, the lead may con-nect the body-contacting portion and the grou

43、nd-contacting portion. ground path total system of conecting leads, straps, and surfaces betwen the controled body and the ground ground straps skin-contacting wrist, leg, or ankle strap that rapidly and safely disipates personel electrostatic charges to the ground and equalizes electrostatic levels

44、 of personel with that of the work surface; strap may contain a curent-limiting resistor for safety hot spots charged islands of material formed when conductive aditives are incompletely distributed, such as un-even topical antistat; may cause ESD damage as a result of the electrical potential of ch

45、arges isolated on them; another form of hot spot may ocur in some aparel constructions when conductive filaments be-come broken and are no longer in electrical contact with one another induced charge electrical charge on a conductor produced by isoltating the conductor from ground, bringing the cond

46、uctor near charged object, then momentarily touching the conductor to ground insulative material material having a surface resistivity of at least 1012ohms/square, or 101ohm-cm volume resistivity ofset voltage voltage created on an isolated conductive plate by an unequal number of positive and negat

47、ive ions on the plate static-disipative clothing body coverings specificaly designed or treated to prevent buildup of electrostatic charge static-disipative materials materials having a surface resistivity betwen 105and 1012ohms/square, or betwen 104and 101ohm-cm volume resistivity static electricit

48、y electrical charge at rest; charge is due to the transfer of electrons within a body (polarization) or from one body to another surface resistivity inverse measure of the conductivity of a material equal to the ratio of the potential gradient to the cur-rent per unit width of the surface; potential

49、 gradient is measured in the direction of curent flow in the mate-rial; is numericaly equal to the surface resistance betwen two electrodes forming oposite sides of a square of the material; size of the square is irelevant over a wide range of sizes; units are ohms per square (ohms/square) topical antistats chemical agents that, when aplied to surfaces of insulative materials, reduce the ability of those sur-faces to acumulate electrostatic charge; usualy act by increasing the surface lubricity of the material NOTE: A secondary efect of one type of topical