ASTM F24-09(2015)
(Test Method)Standard Test Method for Measuring and Counting Particulate Contamination on Surfaces
Standard Test Method for Measuring and Counting Particulate Contamination on Surfaces
ABSTRACT
This test method establishes the standard procedures for measuring and quantizing the size distribution of particulate contamination either on, or washed from, the surface of small electron-device components. The apparatuses and reagents required for this test are also enumerated herein. The number of required test specimens is governed by the dimensions of the component or surface being analyzed. Results shall be interpreted as particles per component or particles per square centimetre of component surface.
SCOPE
1.1 This test method covers the size distribution analysis of particulate contamination, 5 μm or greater in size, either on, or washed from, the surface of small electron-device components. A maximum variation of two to one (±33 % of the average of two runs) should be expected for replicate counts on the same sample.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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Designation: F24 − 09 (Reapproved 2015)
Standard Test Method for
Measuring and Counting Particulate Contamination on
Surfaces
ThisstandardisissuedunderthefixeddesignationF24;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope irregularsurfacecomponents,thecontaminationisremovedby
subjectingthecomponenttoanultrasoniccavitationfieldwhile
1.1 This test method covers the size distribution analysis of
immersed in water containing a detergent.
particulate contamination, 5 µm or greater in size, either on, or
washedfrom,thesurfaceofsmallelectron-devicecomponents. 3.4 The contamination is subsequently transferred to a
Amaximum variation of two to one (633% of the average of membrane filter disk by filtration and then examined micro-
two runs) should be expected for replicate counts on the same scopically.
sample.
3.5 Microscopical analysis of the contaminant is conducted
1.2 The values stated in SI units are to be regarded as at two magnifications using a gating measurement technique
standard. No other units of measurement are included in this with oblique incident lighting.
standard.
3.6 Particles are counted in three size ranges: >100 µm, 25
to 100 µm, 5 to 25 µm, and fibers.
2. Terminology
3.7 For low-contamination levels on irregularly shaped
2.1 Definitions:
components, a procedure for running a blank is described.
2.1.1 particulate contaminant—adiscretequantityofmatter
3.8 The method requires strict adherence to the procedures
that is either foreign to the surface on which it rests or may be
for cleaning apparatus.
washed from the surface on which it rests by the ultrasonic
energy procedure herein described.
4. Apparatus
2.1.2 particle size—themaximumdimensionoftheparticle.
4.1 Microscope, with mechanical stage, approximately 45
2.1.3 fiber—aparticlelongerthan100µmandwithalength
and100×.For100×magnification,therecommendedobjective
to width ratio of greater than 10:1.
is 10 to 12× (but a minimum of 6×) with a numerical aperture
2.1.4 planar surface—a surface that does not move out of
of 0.15 minimum. The optimum equipment is a binocular
the depth of field of the microscope when the area to be
microscope with a micrometer stage. A stereomicroscope
observed is traversed under the highest magnification to be
should not be used in this procedure.
used.
4.2 Ocular Micrometer, B & L 31–16–10.
3. Summary of Method 3
4.3 Stage Micrometer, B & L 31–16–99, having 0.1- to
3.1 This test method comprises two procedures for prepar-
0.01-mm calibration.
ing specimens for microscopical analysis: one for adhered
4.4 Light Source—An external incandescent high-intensity,
particles on planar surfaces and the second for particulate
6-V, 5-A source with transformer.
contamination removed from irregular surfaces.
3.2 A single optical analysis procedure is presented for
particle enumeration in stated size ranges.
The sole source of supply of the ocular micrometer,B&L 31–16–10, known
to the committee at this time is Bausch & Lomb, One Bausch & Lomb Place,
3.3 For planar surfaces, the component is mounted on a
Rochester,NY14604–2701.Ifyouareawareofalternativesuppliers,pleaseprovide
suitableflatsupportandmountedonthemicroscopestage.For
this information toASTM International Headquarters. Your comments will receive
careful consideration at a meeting of the responsible technical committee, which
you may attend.
1 3
This test method is under the jurisdiction of ASTM Committee E21 on Space The sole source of supply of the stage micrometer,B&L31–16–99, known to
Simulation andApplications of SpaceTechnology and is the direct responsibility of the committee at this time is Bausch & Lomb, One Bausch & Lomb Place,
Subcommittee E21.05 on Contamination. Rochester,NY14604–2701.Ifyouareawareofalternativesuppliers,pleaseprovide
Current edition approved Oct. 1, 2015. Published November 2015. Originally this information toASTM International Headquarters. Your comments will receive
approved in 1962. Last previous edition approved in 2009 as F24–09. DOI: careful consideration at a meeting of the responsible technical committee, which
10.1520/F0024-09R15. you may attend.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F24 − 09 (2015)
4.5 Microscope Slides—Glass slides 50 by 75 mm. 7.2.3 For use at low-contamination levels, check the clean-
ness of the equipment by conducting successive blank analy-
4.6 Plastic Film—Wash with membrane-filtered isopropyl
ses.
alcohol.
NOTE 1—Wash bottles for providing membrane-filtered water and
4.7 Solvent Filtering Dispenser.
solvents may be constructed by attaching a Swinney adapter containing a
4.8 Membrane Filter Holder, having 47-mm diameter and
0.8-µm membrane filter to the base of the outlet tube of a Guth wash
bottle.
heat-resistant glass base.
7.2.4 Carefully remove the component to be analyzed from
4.9 Filter Flask,1L.
its container with clean forceps and place it in a clean 500-mL
4.10 Membrane Filters, having 47-mm diameter, 0.45-µm
beakercontaining200mLofmembrane-filtereddistilledwater
pore size, black, grid marked.
towhich0.1%byvolumeofanonionicwettingagenthasbeen
4.11 Vacuum Source—Pump or aspirator (tap recom-
added.
mended).
7.2.5 Cover the beaker with the clean plastic film.
7.2.6 Place the beaker in the ultrasonic tank filled to the
4.12 Flat Forceps, with unserrated tips.
proper level with water.
4.13 Plastic Petri Dishes.
7.2.7 Apply ultrasonic energy to the system for 5 min.
4.14 Ultrasonic Energy Cleaning Apparatus, having 2-L
7.2.8 Preclean a 0.45-µm black grid filter, 47 mm in
minimum capacity (see Appendix X1).
diameter,byholdingitwithforcepsandgentlyrinsingthefilter
surface with a stream of prefiltered distilled water from the
4.15 Beaker, 500-mL, chemical-resistant glass.
wash bottle.
4.16 Double-Faced Pressure-Sensitive Tape.
7.2.9 Place the filter on the fritted base of the filter holder
and clamp the funnel portion in place.
5. Reagents
7.2.10 Transfer the fluid from the beaker into the funnel of
5.1 Isopropyl Alcohol, ACS reagent grade, membrane-
the filter holder.
filtered.
7.2.11 Rinse the beaker with 50 mL of filtered water, or
solvent, and add this rinse to the funnel.
5.2 Nonionic Liquid Wetting Agent, membrane-filtered.
7.2.12 Coverthefunnelwithapieceofcleanaluminumfoil
5.3 Water—Deionizedordistilledwater,membrane-filtered.
or a cleaned 150-mm glass petri dish.
5.4 Membrane-filtered reagents shall be stored in bottles
7.2.13 Apply a vacuum to the filter flask until the liquid has
precleaned as described in 7.2.1 or by use of Swinney
completely passed through the filter. Do not add additional
hypodermic filters in a Guth bottle. A procedure for control
fluid to the funnel after the filter surface has become clear of
analysis of reagent cleanliness is described in Appendix X2.
liquid as this will upset the particle distribution on the filter.
7.2.14 Turn off the vacuum, remove the filter from the
6. Determination of Background Counts
holderbasewithaforceps,andplacethefilterinaplasticpetri
dish with the cover ajar.
6.1 Prepare a blank by following steps 7.2.1 – 7.2.16,
7.2.14.1 Plastic petri dishes
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F24 − 09 F24 − 09 (Reapproved 2015)
Standard Test Method for
Measuring and Counting Particulate Contamination on
Surfaces
This standard is issued under the fixed designation F24; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the size distribution analysis of particulate contamination, 5 μm or greater in size, either on, or
washed from, the surface of small electron-device components. A maximum variation of two to one (633 % of the average of two
runs) should be expected for replicate counts on the same sample.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
2. Terminology
2.1 Definitions:
2.1.1 particulate contaminant—a discrete quantity of matter that is either foreign to the surface on which it rests or may be
washed from the surface on which it rests by the ultrasonic energy procedure herein described.
2.1.2 particle size—the maximum dimension of the particle.
2.1.3 fiber—a particle longer than 100 μm and with a length to width ratio of greater than 10:1.
2.1.4 planar surface—a surface that does not move out of the depth of field of the microscope when the area to be observed
is traversed under the highest magnification to be used.
3. Summary of Method
3.1 This test method comprises two procedures for preparing specimens for microscopical analysis: one for adhered particles
on planar surfaces and the second for particulate contamination removed from irregular surfaces.
3.2 A single optical analysis procedure is presented for particle enumeration in stated size ranges.
3.3 For planar surfaces, the component is mounted on a suitable flat support and mounted on the microscope stage. For irregular
surface components, the contamination is removed by subjecting the component to an ultrasonic cavitation field while immersed
in water containing a detergent.
3.4 The contamination is subsequently transferred to a membrane filter disk by filtration and then examined microscopically.
3.5 Microscopical analysis of the contaminant is conducted at two magnifications using a gating measurement technique with
oblique incident lighting.
3.6 Particles are counted in three size ranges: >100 μm, 25 to 100 μm, 5 to 25 μm, and fibers.
3.7 For low-contamination levels on irregularly shaped components, a procedure for running a blank is described.
3.8 The method requires strict adherence to the procedures for cleaning apparatus.
4. Apparatus
4.1 Microscope, with mechanical stage, approximately 45 and 100×. For 100× magnification, the recommended objective is 10
to 12× (but a minimum of 6×) with a numerical aperture of 0.15 minimum. The optimum equipment is a binocular microscope
with a micrometer stage. A stereomicroscope should not be used in this procedure.
This test method is under the jurisdiction of ASTM Committee E21 on Space Simulation and Applications of Space Technology and is the direct responsibility of
Subcommittee E21.05 on Contamination.
Current edition approved April 1, 2009Oct. 1, 2015. Published April 2009November 2015. Originally approved in 1962. Last previous edition approved in 20042009 as
F24 – 04.F24 – 09. DOI: 10.1520/F0024-09.10.1520/F0024-09R15.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F24 − 09 (2015)
4.2 Ocular Micrometer, B & L 31–16–10.
4.3 Stage Micrometer, B & L 31–16–99, having 0.1- to 0.01-mm calibration.
4.4 Light Source—An external incandescent high-intensity, 6-V, 5-A source with transformer.
4.5 Microscope Slides—Glass slides 50 by 75 mm.
4.6 Plastic Film—Wash with membrane-filtered isopropyl alcohol.
4.7 Solvent Filtering Dispenser.
4.8 Membrane Filter Holder, having 47-mm diameter and heat-resistant glass base.
4.9 Filter Flask, 1 L.
4.10 Membrane Filters, having 47-mm diameter, 0.45-μm pore size, black, grid marked.
4.11 Vacuum Source—Pump or aspirator (tap recommended).
4.12 Flat Forceps, with unserrated tips.
4.13 Plastic Petri Dishes.
4.14 Ultrasonic Energy Cleaning Apparatus, having 2-L minimum capacity (see Appendix X1).
4.15 Beaker, 500-mL, chemical-resistant glass.
4.16 Double-Faced Pressure-Sensitive Tape.
5. Reagents
5.1 Isopropyl Alcohol, ACS reagent grade, membrane-filtered.
5.2 Nonionic Liquid Wetting Agent, membrane-filtered.
5.3 Water—Deionized or distilled water, membrane-filtered.
5.4 Membrane-filtered reagents shall be stored in bottles precleaned as described in 7.2.1 or by use of Swinney hypodermic
filters in a Guth bottle. A procedure for control analysis of reagent cleanliness is described in Appendix X2.
6. Determination of Background Counts
6.1 Prepare a blank by following steps 7.2.1 – 7.2.16, without introduction of the part, for the purpose of determining
background counts.
6.2 Background counts are to be subtracted from the final counts when parts are used.
6.3 If excessively high background counts are obtained, cleaning procedures and handling shall be reexamined before
proceeding.
7. Preparation of Test Specimens
7.1 For Planar Surfaces:
7.1.1 Prepare a 50- by 75-mm microscope slide by adhering to it a 25- by 50-mm strip of double-faced masking tape.
7.1.2 With clean forceps, carefully remove the component to be tested from its container and place it on the tape.
7.1.3 Perform a particle count in accordance with Section 8.
7.2 For Irregular Surfaces:
7.2.1 Ultrasonically clean all glassware, storage containers, and filter holders in hot water containing a detergent.
7.2.2 After washing, rinse the equipment with membrane-filtered water and membrane-filtered isopropyl alcohol and drain dry.
7.2.3 For use at low-contamination levels, check the cleanness of the equipment by conducting successive blank analyses.
NOTE 1—Wash bottles for providing membrane-filtered water and solvents may be constructed by attaching a Swinney adapter containing a 0.8-μm
membrane filter to the base of the outlet tube of a Guth wash bottle.
7.2.4 Carefully remove the component to be analyzed from its container with clean forceps and place it in a clean 500-mL
beaker containing 200 mL of membrane-filtered distilled water to which 0.1 % by volume of a nonionic wetting agent has been
added.
The sole source of supply of the ocular micrometer, B & L 31–16–10, known to the committee at this time is Bausch & Lomb, One Bausch & Lomb Place, Rochester,
NY 14604–2701. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful
consideration at a meeting of the responsible technical committee, which you may attend.
The sole source of supply of the stage micrometer, B & L 31–16–99, known to the committee at this time is Bausch & Lomb, One Bausch & Lomb Place, Rochester,
NY 14604–2701. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful
consideration at a meeting of the responsible technical committee, which you may attend.
F24 − 09 (2015)
7.2.5 Cover the beaker wi
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