ASTM F24-2009 Standard Method for Measuring and Counting Particulate Contamination on Surfaces《表面颗粒状污染物的计数和测量标准方法》.pdf

1、Designation: F 24 09Standard Test Method forMeasuring and Counting Particulate Contamination onSurfaces1This standard is issued under the fixed designation F 24; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revi

2、sion. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the size distribution analysis ofparticulate contamination, 5 m or greater in size, either on, orwashed

3、 from, the surface of small electron-device components.A maximum variation of two to one (633 % of the average oftwo runs) should be expected for replicate counts on the samesample.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstan

4、dard.2. Terminology2.1 Definitions:2.1.1 particulate contaminanta discrete quantity of matterthat is either foreign to the surface on which it rests or may bewashed from the surface on which it rests by the ultrasonicenergy procedure herein described.2.1.2 particle sizethe maximum dimension of the p

5、article.2.1.3 fibera particle longer than 100 m and with a lengthto width ratio of greater than 10:1.2.1.4 planar surfacea surface that does not move out ofthe depth of field of the microscope when the area to beobserved is traversed under the highest magnification to beused.3. Summary of Method3.1

6、This test method comprises two procedures for prepar-ing specimens for microscopical analysis: one for adheredparticles on planar surfaces and the second for particulatecontamination removed from irregular surfaces.3.2 A single optical analysis procedure is presented forparticle enumeration in state

7、d size ranges.3.3 For planar surfaces, the component is mounted on asuitable flat support and mounted on the microscope stage. Forirregular surface components, the contamination is removed bysubjecting the component to an ultrasonic cavitation field whileimmersed in water containing a detergent.3.4

8、The contamination is subsequently transferred to amembrane filter disk by filtration and then examined micro-scopically.3.5 Microscopical analysis of the contaminant is conductedat two magnifications using a gating measurement techniquewith oblique incident lighting.3.6 Particles are counted in thre

9、e size ranges: 100 m, 25to 100 m, 5 to 25 m, and fibers.3.7 For low-contamination levels on irregularly shapedcomponents, a procedure for running a blank is described.3.8 The method requires strict adherence to the proceduresfor cleaning apparatus.4. Apparatus4.1 Microscope, with mechanical stage, a

10、pproximately 45and 1003. For 1003 magnification, the recommended objec-tive is 10 to 123 (but a minimum of 63) with a numericalaperture of 0.15 minimum. The optimum equipment is abinocular microscope with a micrometer stage. A stereomicro-scope should not be used in this procedure.4.2 Ocular Microme

11、ter,B particulate contamination;size distribution analysis; surfacesAPPENDIXES(Nonmandatory Information)(Informative)X1. SELECTION OF ULTRASONIC EQUIPMENTX1.1 To provide uniform and reliable ultrasonic energy, thefollowing factors should be considered in selecting the equip-ment:X1.1.1 The type of t

12、ransducer and method of bondingshould be selected so that frequency, inductance, and couplingcoefficient are unchanged by heat, vibration, and age.X1.1.2 The type of transducer and frequency should beselected to minimize focusing of energy in specific areas.X1.1.3 The power of the transducer should

13、be chosen toprevent standing waves (which do not allow vaporous cavita-tion) and to prevent physical damage and cavitation erosion.X2. METHOD OF COUNTING AND MEASURING PARTICLESX2.1 In obtaining the number of particles of a certain sizerange, the number of particles on a representative number ofgrid

14、 squares on the membrane filter paper is counted. From thiscount, the total number of particles, which would be presentstatistically on the total filtered area of 100 imprinted gridsquares, is calculated.X2.2 If the total number of particles of a certain size rangeis estimated to be between 1 and 50

15、, count the number ofparticles on all 100 grid squares.X2.3 If the total number of particles of a certain size rangeis estimated to be between 50 and 1000, count the number ofparticles in 20 randomly chosen grid squares and multiply thisnumber by 5 to obtain the statistical total particle count.X2.4

16、 If the total number of particles of a certain size rangeis estimated to be between 1000 and 5000, count the number ofparticles on 10 randomly chosen grid squares and multiply thisnumber by 10 to obtain the statistical total particle count.X2.5 If the estimated total number of particles of a givensi

17、ze range exceeds 5000, particles are counted in standardfractions of grid areas (Fig. X2.1).X2.6 Count the particles within at least 10 of thesefractional areas.X2.7 Multiply the average count per fractional area by theNOTE 1With membrane filter on stage, movement of the stage makesparticles appear

18、to pass the divisions on the measuring eyepiece.FIG. X2.1 Alternative Unit AreasF24093ratio of the effective filtration area, to the area counted.X2.8 Select fractional area so that there will be no morethan about 50 particles of a size range.ASTM International takes no position respecting the valid

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20、ct to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquart

21、ers. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard

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