1、Designation: F1394 92 (Reapproved 2012)Standard Test Method forDetermination of Particle Contribution from Gas DistributionSystem Valves1This standard is issued under the fixed designation F1394; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONSemiconductor clean rooms are serviced by high-purity gas distribution systems. This test met
3、hodpresents a procedure that may be applied for the evaluation of one or more components considered foruse in such systems.1. Scope1.1 This test method covers gas distribution system compo-nents intended for installation into a high-purity gas distribu-tion system.1.1.1 This test method describes a
4、procedure designed todraw statistically significant comparisons of particulate gen-eration performance of valves tested under aggressive condi-tions.1.1.2 This test method is not intended as a methodology formonitoring on-going particle performance once a particularvalve has been tested.1.2 This tes
5、t method utilizes a condensation nucleus counter(CNC) applied to in-line gas valves typically used in semicon-ductor applications. It applies to automatic and manual valvesof various types (such as diaphragms or bellows), 6.3 through12.7-mm (14 through12-in.) size. For applications of this testmetho
6、d to larger valves, see the table in the appendix.1.2.1 Valves larger than 12.7 mm (12 in.) can be tested bythis methodology. The test stand must be sized accordingly.Components larger than 12.7 mm (12 in.) should be testedwhile maintaining a Reynolds number of 20 000 to 21 000.This is the Reynolds
7、number for 12.7-mm (12-in.) componentstested at a velocity of 30.5 m/s (100 ft/s).1.3 Limitations:1.3.1 This test method is applicable to total particle countgreater than the minimum detection limit (MDL) of thecondensation nucleus particle counter and does not considerclassifying data into various
8、size ranges.1.3.1.1 It is questionable whether significant data can begenerated from nondynamic components (such as fittings andshort lengths of tubing) to compare, with statisticalsignificance, to the data generated from the spool piece. Forthis reason, this test method cannot reliably support comp
9、ari-sons between these types of components.1.3.1.2 If detection or classification of particles, or both, inthe size range of laser particle counter (LPC) technology is ofinterest, an LPC can be utilized for testing components. Flowrates, test times, sampling apparatus, and data analysis outlinedin t
10、his test method do not apply for use with an LPC. Becauseof these variations, data from CNCs are not comparable to datafrom LPCs.1.3.2 This test method specifies flow and mechanical stressconditions in excess of those considered typical. These condi-tions should not exceed those recommended by the m
11、anufac-turer. Actual performance under normal operating conditionsmay vary.1.3.3 The test method is limited to nitrogen or clean dry air.Performance with other gases may vary.1.3.4 This test method is intended for use by operators whounderstand the use of the apparatus at a level equivalent to sixmo
12、nths of experience.1.3.5 The appropriate particle counter manufacturers oper-ating and maintenance manuals should be consulted whenusing this test method.1.4 The values stated in SI units are to be regarded as thestandard. The inch-pound units given in parentheses are forinformation only.1.5 This st
13、andard does not purport to address all of thesafety concerns, if any, associated with its use. It is the1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.10 on Contamina-tion Control.Current edition approved July 1, 2
14、012. Published August 2012. Originallyapproved in 1992. Last previous edition approved in 2005 as F139492(2005). DOI:10.1520/F1394-92R12.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1responsibility of the user of this standard to es
15、tablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in Section 6, Hazards.2. Referenced Documents2.1 Federal Standard:FED-STD-209D Federal Standard Clean Room and WorkStation Requirements, Contr
16、olled Environment23. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 background countscounts contributed by the testapparatus (including counter electrical noise) with the spoolpiece in place of the test object.3.1.2 condensation nucleus counter (CNC)light scatteringinstrument th
17、at detects particles in a gaseous stream bycondensing supersaturated vapor upon the particles.3.1.3 control productsample component that givesconsistent, stabilized counts at or below the expected countsfrom the test components. The product is run periodically inaccordance with the test protocol to
18、ensure that the system isnot contributing particles significantly different from expectedlevels.3.1.3.1 DiscussionThe control product may have to bechanged periodically if its performance degrades with testing.Between tests, the control product must be bagged in accor-dance with the original manufac
19、turers packaging and stored ina clean manner. The control product is used to allow the systemto consider the disruption caused by the activation of any valveunder test, such as significant fluctuations in flow, pressure,turbulence, and vibration.3.1.4 dynamic testtest performed to determine particle
20、contribution as a result of valve actuation.3.1.5 impact testtest performed to determine particle con-tribution as a result of mechanical shock while the componentis in the fully open position.3.1.6 sampling timethe time increment over which countsare recorded.3.1.7 sample flow ratethe volumetric fl
21、ow rate drawn bythe counter for particle detection. The counter may draw higherflow for other purposes (for example, sheath gas).3.1.8 spool piecea null component consisting of a straightpiece of electropolished tubing and appropriate fittings used inplace of the test component to establish the base
22、line.3.1.9 standard conditions101.3 kPa, 20C (14.73 psia,68F).3.1.10 static testa test performed on an as-received com-ponent in the fully open position. This test establishes particu-late contribution by the valve to the counting system.3.1.11 test durationtotal time required to complete the testpr
23、ocedure.3.1.12 test flow ratevolumetric flow at test pressure andtemperature.3.1.13 test pressurepressure immediately downstream ofthe test component.3.1.14 test velocitythe average velocity of the test gas inthe outlet tube of the test valve (volumetric flow at ambientpressure and temperature divid
24、ed by the internal cross-sectional area of the valve outlet). In this test method, the testvelocity is specified to maintain a Reynolds number of 20 000to 21 000 (see the table in the appendix).3.2 Abbreviations:3.2.1 LPClaser particle counter.4. Significance and Use4.1 The purpose of this test meth
25、od is to define a procedurefor testing components intended for installation into a high-purity gas distribution system. Application of this test methodis expected to yield comparable data among components testedfor the purposes of qualification for this installation.4.2 Background TestingThis test m
26、ethod uses backgroundtesting to ensure that the system is not contributing particlesabove a low, acceptable level. This ensures that counts seen arefrom the test device, not from a contaminated system. Thetechniques used to obtain background counts do not produceconditions identical to the condition
27、s existing when a testdevice is in place. It is recommended that the control productsbe run periodically to see that they give consistent results.These control products should be the lowest particle releaseproducts. They will be additional proof that the system is notcontributing excess particles du
28、ring the static, dynamic, orimpact portions of the test.4.3 This test method can be used for testing lengths oftubing. The flow criteria will be identical to that indicated forvalves.Atubing test would only include the static background,the impact background, and the static and impact portions ofthe
29、 method.Adynamic portion could be added by actuating theupstream pneumatic valve (PV1), thus creating a flow surge tothe test length of tubing.5. Apparatus5.1 Test GasClean, dry nitrogen or air is to be used(minimum dryness 40C (40F) dew point at 689 kPa gagepressure (100 psig) and C, then the diffe
30、rence is significantor,lD C, then the difference is not significant10.3.4 Sample calculations based on data shown in Figs.X1.1-X1.6.10.4 To determine if Valve A generated a significantlygreater number of particles (statistically) than backgroundduring the first 10 min of the static test:10.4.1 For t
31、he valve data during the first 10 min of the statictest:kk = 47 counts,v = 0.00023 standard m3(0.5 standard ft3)l1= k/v = 94, ands12= k/v2= 188.10.4.2 For the background data during the first 10 min:kk =3v = 0.00023 standard m3(0.5 standard ft3),l2= k/v = 6, andS22= k/v2= 12.Then: SD=(S12+ S22)1/2=
32、(188 + 12) = 14.14 andlD= l1 l2=946=88.10.4.3 The critical value in percent is calculated as:C98C98= ZbSD, where Zb= 2.08C98= 29.41, orC99= ZbSD, where Zb= 2.33C99= 32.95, orC99.9= ZbSD, where Zb= 3.17,C99.9= 44.82.10.4.4 lDis greater than the percent of C99.9; therefore, itcan be stated with 99.9 %
33、 confidence that Valve A generated asignificantly greater number of particles (statistically) thanbackground during the first 10 min of the static test.10.5 To determine if Valve B generated a significantlygreater number of particles (statistically) than Valve A duringthe first 10 min of dynamic tes
34、ting:10.5.1 Applying the same calculations in percent as in 10.3to these two sets of data to determine that:lDlD= 114,C98= 102.5,C99= 114.8, andC99.9= 156.2.10.5.2 lDis greater in percent than C98but not greater thanC99; therefore, it can be stated with only 99 % confidence thatValve B generated a s
35、tatistically significant greater number ofparticles than Valve A during the first 10 min of dynamictesting.10.6 For comparing counts generated by a single valve tobackground counts, the data shown on the summary sheetF1394 92 (2012)6should be collected on each valve and the calculations per-formed.
36、If more than one of the same valve is tested, datashould be summed and calculations performed based on thetotal number of counts and volume sampled.10.7 For comparing counts generated by a single valve typeto counts generated by a different valve type, the data shown onthe summary sheet should be co
37、llected and the calculationsperformed. If more than one of the same valve is tested, datashould be summed and calculations performed based on thetotal number of counts and volume sampled.10.8 Asummary of all confidence statements should accom-pany the data and be formulated as follows in Table 1:10.
38、9 A summary of all confidence statements for compari-sons between valves should accompany the data and beformulated as follows in Table 2:11. Report11.1 Report the following test conditions:11.1.1 Date and time of test,11.1.2 Operator,11.1.3 Test flow rate, m3/s (standard ft3/min),11.1.4 Test pressu
39、re, kPa gage pressure (psig),11.1.5 Valve type, manufacturer, serial number, lot number,and model number,11.1.6 CNC manufacturer, serial number, sample flow rate,standard m3/s (standard ft3/min),11.1.7 Test gas type and dew point (C) model number, andcalibration date,11.1.8 Schematic of the test app
40、aratus, including manufac-turers and model numbers of all test apparatus components,11.1.9 Calibration dates for the flow meters and the test dateshould also be reported (see Fig. X1.7 for sample data sheet).11.2 Data AcquisitionThe data link between the counterand any data acquisition system should
41、 be qualified andchecked for accuracy and consistency.11.3 Data Presentation:11.3.1 Graph the static, dynamic and impact portions of thetest separately as counts per min (measured by the counter)versus time, including the appropriate background measuredwith the spool piece in place) with each. Also
42、graph the entiredata set as counts per min versus time. If different valves are tobe compared, graph their entire data sets together. (See Figs.X1.8-X1.11).11.3.2 Record and present the entire raw data set in tabularform as shown in Fig. X1.12 and Fig. X1.13.12. Precision and Bias12.1 The precision
43、and bias of the data generated by this testmethod is limited to the precision and bias of the particlemeasuring instruments utilized.13. Keywords13.1 condensation nucleus center; contamination; gas dis-tribution; gas distribution valves; isokinetic sampling; nitro-gen; particle contamination; partic
44、le counter; particles; semi-conductor processingTABLE 1 Particle Data Confidence Statement Summary SheetValve A generated more particles than background98 % Confident(Y/N)99 % Confident(Y/N)99.9 % Confident(Y/N)Static, first 10 min _ _ _Static, 60 min _ _ _Dynamic, first 10 min _ _ _Dynamic, 60 min
45、_ _ _Impact, first minute _ _ _Impact, first 10 min _ _ _Impact, 40 min _ _ _TABLE 2 Particle Data Confidence Statement Summary SheetValve B generated more particles than Valve A98 % Confident(Y/N)99 % Confident(Y/N)99.9 % Confident(Y/N)Static, first 10 min _ _ _Static, 60 min _ _ _Dynamic, first 10
46、 min _ _ _Dynamic, 60 min _ _ _Impact, first minute _ _ _Impact, first 10 min _ _ _Impact, 40 min _ _ _Valve A generated more particles than Valve B98 % Confident(Y/N)99 % Confident(Y/N)99.9 % Confident(Y/N)Static, first 10 min _ _ _Static, 60 min _ _ _Dynamic, first 10 min _ _ _Dynamic, 60 min _ _
47、_Impact, first minute _ _ _Impact, first 10 min _ _ _Impact, 40 min _ _ _F1394 92 (2012)7APPENDIX(Nonmandatory Information)X1. Additional Test DataX1.1 See Table X1.1 and Figs. X1.1-X1.13.TABLE X1.1 Matrix of Typical Test Flow Rates Nominal Outside Diameters0 TestComponentNominalDiameter, in.1 TestC
48、omponentOutlet InsideDiameter, in.2 ReynoldsNumber3 AverageTest Velocity,ft/s4 TestFlow Rate,ft3/min114 0.180 20 600 224 2.4238 0.305 20 600 132 4.0312 or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F1394 92 (2012)27
