ASTM_F_24_-_09_2015.pdf

Designation:F2409(Reapproved 2015)Standard Test Method forMeasuring and Counting Particulate Contamination onSurfaces1This standard is issued under the fixed designation F24;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()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 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 thisstandard.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 particle.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 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 stated 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 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 three 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,approximately 45and 100.For 100 magnification,the recommended objectiveis 10 to 12(but a minimum of 6)with a numerical apertureof 0.15 minimum.The optimum equipment is a binocularmicroscope with a micrometer stage.A stereomicroscopeshould not be used in this procedure.4.2 Ocular Micrometer,B&L 311610.24.3 Stage Micrometer,B&L 311699,3having 0.1-to0.01-mm calibration.4.4 Light SourceAn external incandescent high-intensity,6-V,5-A source with transformer.1This test method is under the jurisdiction of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the direct responsibility ofSubcommittee E21.05 on Contamination.Current edition approved Oct.1,2015.Published November 2015.Originallyapproved in 1962.Last previous edition approved in 2009 as F24 09.DOI:10.1520/F0024-09R15.2The sole source of supply of the ocular micrometer,B&L 311610,knownto the committee at this time is Bausch&Lomb,One Bausch&Lomb Place,Rochester,NY146042701.If you are aware of alternative suppliers,please providethis information to ASTM International Headquarters.Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.3The sole source of supply of the stage micrometer,B&L 311699,known tothe committee at this time is Bausch&Lomb,One Bausch&Lomb Place,Rochester,NY146042701.If you are aware of alternative suppliers,please providethis information to ASTM International Headquarters.Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.5 Microscope SlidesGlass slides 50 by 75 mm.4.6 Plastic FilmWash with membrane-filtered isopropylalcohol.4.7 Solvent Filtering Dispenser.4.8 Membrane Filter Holder,having 47-mm diameter andheat-resistant glass base.4.9 Filter Flask,1 L.4.10 Membrane Filters,having 47-mm diameter,0.45-mpore size,black,grid marked.4.11 Vacuum SourcePump or aspirator(tap recom-mended).4.12 Flat Forceps,with unserrated tips.4.13 Plastic Petri Dishes.4.14 Ultrasonic Energy Cleaning Apparatus,having 2-Lminimum capacity(see Appendix X1).4.15 Beaker,500-mL,chemical-resistant glass.4.16 Double-Faced Pressure-Sensitive Tape.5.Reagents5.1 Isopropy