ASTM F24-09

Standard 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 apparatus 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.

General Information

• Status: Historical
• Publication Date: 31-Mar-2009
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: E21 - Space Simulation and Applications of Space Technology
• Drafting Committee: E21.05 - Contamination

Relations

• Replaces: ASTM F24-04 - Standard Method for Measuring and Counting Particulate Contamination on Surfaces
• Effective Date: 01-Apr-2009
• Replaced By: ASTM F24-09(2015) - Standard Test Method for Measuring and Counting Particulate Contamination on Surfaces
• Effective Date: 01-Oct-2015
• Referred By: ASTM E2217-12(2019) - Standard Practice for Design and Construction of Aerospace Cleanrooms and Contamination Controlled Areas
• Effective Date: 01-Apr-2009
• Referred By: ASTM E2088-06(2021) - Standard Practice for Selecting, Preparing, Exposing, and Analyzing Witness Surfaces for Measuring Particle Deposition in Cleanrooms and Associated Controlled Environments
• Effective Date: 01-Apr-2009
• Referred By: ASTM E2042/E2042M-09(2021) - Standard Practice for Cleaning and Maintaining Controlled Areas and Clean Rooms
• Effective Date: 01-Apr-2009
• Referred By: ASTM E1560-18 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue From Cleanroom Wipers
• Effective Date: 01-Apr-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F24 − 09
StandardTest Method for
Measuring and Counting Particulate Contamination on
1
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.
2
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.
2
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
1
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 April 1, 2009. Published April 2009. Originally this information toASTM International Headquarters. Your comments will receive
1
approved in 1962. Last previous edition approved in 2004 as F24–04. DOI: careful consideration at a meeting of the responsible technical committee, which
10.1520/F0024-09. you may attend.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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F24−09
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 construct
...

This document is not anASTM standard and is intended only to provide the user of anASTM 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:F24–04 Designation:F24–09
Standard Test Method for
Measuring and Counting Particulate Contamination on
1
Surfaces
ThisstandardisissuedunderthefixeddesignationF 24;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
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.Amaximum 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 Forplanarsurfaces,thecomponentismountedonasuitableflatsupportandmountedonthemicroscopestage.Forirregular
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 1003. For 1003 magnification, the recommended objective is
10to123(butaminimumof63)withanumericalapertureof0.15minimum.Theoptimumequipmentisabinocularmicroscope
with a micrometer stage. A stereomicroscope should not be used in this procedure.
2
4.2 Ocular Micrometer,B&L 31–16–10.
3
4.3 Stage Micrometer,B&L 31–16–99, having 0.1- to 0.01-mm calibration.
1
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 Sept.April 1, 2004.2009. Published September 2004.April 2009. Originally approved in 1962. Last previous edition approved in 20002004 as
F 24 – 004.
2
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.
3
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

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F24–09
4.4 Light Source— An external incandescent high-intensity, 6-V, 5-A source with transformer.
...