ASTM E493/E493M-11(2022)
(Practice)Standard Practice for Leaks Using the Mass Spectrometer Leak Detector in the Inside-Out Testing Mode
Standard Practice for Leaks Using the Mass Spectrometer Leak Detector in the Inside-Out Testing Mode
SIGNIFICANCE AND USE
6.1 Methods A or B are useful in testing hermetically-sealed devices with internal volumes. Maximum acceptable leak rates have been established for microelectronic devices to assure performance characteristics will not be affected by in-leakage of air, water vapor or other contaminants over the projected life expected. Care must be taken to control the bombing pressure, bombing time and dwell time after bombing or the results can vary substantially.
SCOPE
1.1 This practice2 covers procedures for testing devices that are sealed prior to testing, such as semiconductors, hermetically enclosed relays, pyrotechnic devices, etc., for leakage through the walls of the enclosure. They may be used with various degrees of sensitivity (depending on the internal volume, the strength of the enclosure, the time available for preparation of test, and on the sorption characteristics of the enclosure material for helium). In general practice the sensitivity limits are from 10−10 to 10−6 Pa m3/s (10−9 standard cm3/s to 10−5 standard cm3/s at 0°C) for helium, although these limits may be exceeded by several decades in either direction in some circumstances.
1.2 Two test methods are described:
1.2.1 Test Method A—Test part preparation by bombing.
1.2.2 Test Method B—Test part preparation by prefilling.
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E493/E493M − 11 (Reapproved 2022)
Standard Practice for
Leaks Using the Mass Spectrometer Leak Detector in the
Inside-Out Testing Mode
This standard is issued under the fixed designation E493/E493M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope mendations issued by the World Trade Organization Technical
2 Barriers to Trade (TBT) Committee.
1.1 This practice covers procedures for testing devices that
are sealed prior to testing, such as semiconductors, hermeti-
2. Referenced Documents
cally enclosed relays, pyrotechnic devices, etc., for leakage
2.1 ASTM Standards:
through the walls of the enclosure. They may be used with
E1316Terminology for Nondestructive Examinations
various degrees of sensitivity (depending on the internal
volume, the strength of the enclosure, the time available for 2.2 Other Documents:
preparation of test, and on the sorption characteristics of the SNT-TC-1ARecommended Practice for Personnel Qualifi-
cation and Certification in Nondestructive Testing
enclosure material for helium). In general practice the sensi-
−10 −6 3 −9
tivity limits are from 10 to 10 Pa m /s (10 standard ANSI/ASNT CP-189ASNT Standard for Qualification and
3 −5 3 4
Certification of Nondestructive Testing Personnel
cm /sto10 standardcm /sat0°C)forhelium,althoughthese
limits may be exceeded by several decades in either direction MIL-STD-410Nondestructive Testing Personnel Qualifica-
tion and Certification
in some circumstances.
NAS-410Certification and Qualification of Nondestructive
1.2 Two test methods are described:
Test Personnel
1.2.1 Test Method A—Test part preparation by bombing.
1.2.2 Test Method B—Test part preparation by prefilling.
3. Terminology
1.3 Units—The values stated in either SI or std-cc/sec units
3.1 Definitions—For definitions of terms used in this
are to be regarded separately as standard. The values stated in
practice, see Terminology E1316, Section E.
each system may not be exact equivalents: therefore, each
system shall be used independently of the other. Combining
4. Summary of Practice
values from the two systems may result in non-conformance
4.1 Thetestmethodscoveredinthispracticerequirethatthe
with the standard.
test part contain helium at some calculable pressure at the time
1.4 This standard does not purport to address all of the
oftest.Ifthedevicecannotbesealedwithaknownpressureof
safety concerns, if any, associated with its use. It is the
helium inside, it is necessary to “bomb” the part in a helium
responsibility of the user of this standard to establish appro-
pressurechamberinordertointroduceheliumintothetestpart
priate safety, health, and environmental practices and deter-
if a leak exists.
mine the applicability of regulatory limitations prior to use.
4.2 After the test part has been subjected to helium pressur-
1.5 This international standard was developed in accor-
izing means, it is placed in an enclosure which is then
dance with internationally recognized principles on standard-
evacuatedandcoupledtoamassspectrometerleakdetector.In
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This practice is under the jurisdiction of ASTM Committee E07 on Nonde- Standards volume information, refer to the standard’s Document Summary page on
structive Testing and is the direct responsibility of Subcommittee E07.08 on Leak the ASTM website.
Testing Method. AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
in 1973. Last previous edition approved in 2017 as E493/E493M–11(2017). DOI: Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
10.1520/E0493_E0493M-11R22. Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
Theinside-outtestingmodeischaracterizedbyanexternalvacuumandinternal dodssp.daps.dla.mil.
pressure. This standard covers “evacuated,” “sealed with tracer,” and “air-sealed” Available fromAerospace IndustriesAssociation ofAmerica, Inc. (AIA), 1000
testing procedures shown in Terminology E1316. WilsonBlvd.,Suite1700,Arlington,VA22209-3928,http://www.aia-aerospace.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E493/E493M − 11 (2022)
the event of a leak, an output signal will be obtained from the 9. Materials
leak detector. If the actual leak rate of the test part must be
9.1 Helium supply from a regulated source.
known, this must then be calculated from the output reading
9.2 Liquid Nitrogen supply (if required by mass spectrom-
and the test parameters.
eter leak detector).
5. Personnel Qualification
9.3 Dry Air or Nitrogen (if required) for washing surface
5.1 If specified in the contractual agreement, personnel
helium from test objects.
performing examinations to this practice shall be qualified in
accordancewithanationally-recognizedNDTpersonnelquali-
10. Calibration
fication practice or standard, such as ANSI/ASNT CP-189,
10.1 Calibrate the mass spectrometer leak detector (MSLD)
SNT-TC-1A, MIL-STD-410, NAS-410, or a similar document
with a calibrated leak to read directly in Pa m /s or standard
and certified by the employer or certifying agency, as appli-
cm /sofheliuminaccordancewiththemanufacturers’instruc-
cable.The practice or standard used and its applicable revision
tions.
shall be identified in the contractual agreement between the
using parties.
11. Procedure
6. Significance and Use
11.1 Test Method A (Bombing):
11.1.1 Place a quantity of sealed parts to be tested in a
6.1 MethodsAorBareusefulintestinghermetically-sealed
deviceswithinternalvolumes.Maximumacceptableleakrates pressure vessel.
11.1.2 Then either flush the pressure vessel with helium or
have been established for microelectronic devices to a
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