ASTM F1396-93(2012)
(Test Method)Standard Test Method for Determination of Oxygen Contribution by Gas Distribution System Components
Standard Test Method for Determination of Oxygen Contribution by Gas Distribution System Components
SIGNIFICANCE AND USE
3.1 This test method defines a procedure for testing components being considered for installation into a high-purity gas distribution system. Application of this test method is expected to yield comparable data among components tested for purposes of qualification for this installation.
SCOPE
1.1 This test method covers a procedure for testing components for oxygen contribution to ultra-high purity gas distribution systems at ambient temperature. In addition, this test method allows testing of the component at elevated ambient temperatures as high as 70°C.
1.2 This test method applies to in-line components containing electronics grade materials such as those used in a semiconductor gas distribution system.
1.3 Limitations:
1.3.1 This test method is limited by the sensitivity of current instrumentation, as well as the response time of the instrumentation. This test method is not intended to be used for test components larger than 12.7-mm (1/2-in.) outside diameter nominal size. This test method could be applied to larger components; however, the stated volumetric flow rate may not provide adequate mixing to ensure a representative sample. Higher flow rates may improve the mixing but excessively dilute the sample.
1.3.2 This test method is written with the assumption that the operator understands the use of the apparatus at a level equivalent to six months of experience.
1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.5 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 6.
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Standards Content (Sample)
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Designation: F1396 − 93 (Reapproved 2012)
Standard Test Method for
Determination of Oxygen Contribution by Gas Distribution
System Components
This standard is issued under the fixed designation F1396; 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.
INTRODUCTION
Semiconductor clean rooms are serviced by high-purity gas distribution systems. This test method
presents a procedure that may be applied for the evaluation of one or more components considered for
use in such systems.
1. Scope bility of regulatory limitations prior to use. Specific hazard
statements are given in Section 6.
1.1 This test method covers a procedure for testing compo-
nents for oxygen contribution to ultra-high purity gas distribu-
2. Terminology
tion systems at ambient temperature. In addition, this test
2.1 Definitions:
method allows testing of the component at elevated ambient
temperatures as high as 70°C. 2.1.1 baseline—the instrument response under steady state
conditions.
1.2 This test method applies to in-line components contain-
2.1.2 glove bag—an enclosure that contains a controlled
ing electronics grade materials such as those used in a
atmosphere. A glove box could also be used for this test
semiconductor gas distribution system.
method.
1.3 Limitations:
2.1.3 heat trace— heating of a component, spool piece, or
1.3.1 Thistestmethodislimitedbythesensitivityofcurrent
teststandbyauniformandcompletewrappingoftheitemwith
instrumentation, as well as the response time of the instrumen-
resistant heat tape.
tation. This test method is not intended to be used for test
components larger than 12.7-mm ( ⁄2-in.) outside diameter
2.1.4 minimum detection limit (MDL) of the instrument—the
nominal size. This test method could be applied to larger lowest instrument response detectable and readable by the
components; however, the stated volumetric flow rate may not
instrument, and at least two times the amplitude of the noise.
provide adequate mixing to ensure a representative sample.
2.1.5 response time—the time required for the system to
Higher flow rates may improve the mixing but excessively
reach steady state after a change in concentration.
dilute the sample.
2.1.6 spool piece—a null component, consisting of a
1.3.2 This test method is written with the assumption that
straightpieceofelectropolishedtubingandappropriatefittings,
the operator understands the use of the apparatus at a level
used in place of the test component to establish the baseline.
equivalent to six months of experience.
2.1.7 standard conditions—101.3 kPa, 0.0°C (14.73 psia,
1.4 The values stated in SI units are to be regarded as the
32°F).
standard. The inch-pound units given in parentheses are for
2.1.8 test component—any device being tested, such as a
information only.
valve, regulator, or filter.
1.5 This standard does not purport to address all of the
2.1.9 test stand—the physical test system used to measure
safety concerns, if any, associated with its use. It is the
impurity levels.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 2.1.10 zero gas—a purified gas that has an impurity concen-
tration below the MDLof the analytical instrument.This gas is
to be used for both instrument calibration and component
This test method is under the jurisdiction of ASTM Committee F01 on
testing.
Electronicsand is the direct responsibility of Subcommittee F01.10 on Contamina-
tion Control.
2.2 Symbols:
Current edition approved July 1, 2012. Published August 2012. Originally
2.2.1 P —The inlet pressure measured upstream of the
approved in 1992. Last previous edition approved in 2005 as F1396 – 93(2005). 1
DOI: 10.1520/F1396-93R12. purifier and filter in the test apparatus.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1396 − 93 (2012)
2.2.2 P —The outlet pressure measured downstream of the shall not be more than 600 mm, so as to minimize the effect
analyzer in the test apparatus. (adsorption/desorption) of the sample line on the result. The
sample line shall have no more than two mechanical joints.
2.2.3 ppbv—Parts per billion by volume assuming ideal gas
4.1.4 Valves, diaphragm or bellows type, capable of unim-
behavior, equivalent to nmole/mole (such as nL/L). The same
paired operation at 94°C (200°F). The use of all-welded,
as molar parts per billion (ppb).
all-metal valves is preferred.
2.2.4 ppbw—Parts per billion by weight (such as ng/g).
4.2 Instrumentation:
2.2.5 ppmv—Parts per million by volume assuming ideal
4.2.1 Oxygen Analyzer—The oxygen analyzer is to be
gas behavior, equivalent to µmole/mole (such as µL/L). The
placed downstream of the test component. Accurate baseline
same as molar parts per million (ppm).
readings must be obtained prior to and subsequent to each of
2.2.6 ppmw—Parts per million by weight (such as µg/g).
the tests. Excessive deviations in baseline levels (610 ppbv)
2.2.7 Q —the bypass sample flow not going through the
before or after the tests require that all results be rejected. The
analytical system. analyzer must be capable of accurately recording changes in
oxygen concentrations on a real time basis.
2.2.8 Q —the total sample flow through the analytical
4.2.2 Oxygen Analyzer Calibration—Zero gas shall be at an
system.
oxygen level below the MDL of the instrument, supplied by
2.2.9 Q —the flow through the spool piece or component.
s
purifiedgas,withthepurifierincloseproximitytotheanalyzer.
2.2.10 T —the temperature of the air discharged by the
a The instrument’s internal standard, if available, is to be used
analyzer’s cooling exhaust.
for the span calibration.Alternatively, span gas from a cylinder
2.2.11 T —the temperature of the spool piece or component. may be used.
s
2.2.11.1 Discussion—Precautions must be taken to insure
4.3 Pressure and Flow Control—Upstream pressure is to be
that the temperature measured by the thermocouple is as close
controlled with a regular upstream of the test component. Flow
as possible to that of the spool piece and test component.
is to be controlled at a point downstream of the sampling port
Appropriate insulation and conductive shield should be used to
and monitored at that point.Amass flow controller is preferred
achieve as uniform a temperature as possible. The thermo-
for maintaining the flow as described in 7.4. Sampling is to be
couple must be in contact with the outside wall of the
performed via a tee in the line, with a section of straight tubing
component or spool piece.
before the mass flow controller. All lines must conform to
2.2.12 V-1, V-2—inlet and outlet valves of bypass loop,
4.1.3. Inlet pressure is monitored by P .Test flow is the sum of
respectively.
Q and Q . Q is directly controlled, and Q is the measured
1 2 1 2
flow through the analyzer. Refer to Fig. 1.
2.2.13 V-3, V-4—inlet and outlet valves of test loop, respec-
tively.
4.4 Bypass Loop—The design of the bypass loop is not
restrictedtoanyonedesign.Itcouldbe,forexample,a3.2-mm
3. Significance and Use
( ⁄8-in) 316L stainless steel coil or a flexible tube section. This
3.1 This test method defines a procedure for testing compo-
allows the flexibility necessary to install test components of
nents being considered for installation into a high-purity gas
different lengths.
distribution system.Application of this test method is expected
5. Hazards
to yield comparable data among components tested for pur-
poses of qualification for this installation.
5.1 It is required that the user have a working knowledge of
the respective instrumentation and that the user practice proper
4. Apparatus
handling of test components for trace oxygen analysis. Good
4.1 Materials:
laboratory practices must also be understood.
4.1.1 Nitrogen or Argon, clean and dry, as specified in 7.5.
5.2 It is required that the user be familiar with proper
4.1.2 Spool Piece, that can be installed in place of the test
component installation, and that the test components be in-
component is required. This piece is to be a straight section of
stalled on the test stand in accordance with manufacturer’s
316Lelectropolished stainless steel tubing with no restrictions.
instructions.
The length of the spool piece shall be 200 mm.The spool piece
has the same end connections as the test component.
4.1.2.1 Components With Stub Ends—Use compression fit-
tings with nylon or teflon ferrules to connect the spool piece
and test component to the test loop. Keep the purged glove bag
around each component for the duration of the test. In the case
of long pieces of electropolished tubing, use two glove bags,
one at each end.
4.1.3 Tubing, used downstream of the test component shall
be 316L electropolished stainless steel seamless tubing. The
diameter of the sample line to the analyzer shall not be larger
than 6.4 mm ( ⁄4 in.).The length of the sample line from the tee
(installed upstream of the pressure gage P ) to the analyzer FIG. 1 Test Schematic
F1396 − 93 (2012)
5.3 Do not exceed ratings (such as pressure, temperature, yield the flow rates required by the specification for an inlet
and flow) of component. pressure of 30 psig. The gas flow rate Q is set to 1 L/min.
s
5.4 Gloves are to be worn for all steps. 8.4 Inlet gas pressure is controlled by a pressure regulator
and measured immediately upstream of the purifier by an
5.5 Limit exposure of the instrument and test component to
electronic grade pressure gage. Flow measurement is carried
atmospheric contamination before and during the test.
outbyamassflowcontroller(MFC)locateddownstreamofthe
analyzer. The outlet pressure of the gas is measured immedi-
6. Calibration
ately downstream of the analyzer by another electronic grade
6.1 Calibrate instruments using standard laboratory prac-
pressure gage. The MFC along with its digital readout should
tices and manufacturer’s recommendations.
be calibrated before use to control and display the gas flow rate
Q .
7. Conditioning
8.5 The temperature of the spool piece, test specimen,
7.1 Ensure that adequate mixing of the test gas is attained.
analyzer cell compartment, and the oxygen concentration
measured by the analyzer can either be recorded continuously
7.2 Pressure—Test component at 200 kPa gage (30 psig)
by a 25 channel data logger or collected and stored in a
measured at P .
computer using a data acquisition program.
7.3 Temperature— T is to be in the ambient temperature
s
range of 18 to 26°C (64 to 78°F) and in the higher mean
9. Procedure (see Fig. 2)
temperature range of 69 to 71°C (156 to 160°F). T must not
a
9.1 Bake-Out—With the spool piece installed and valves
deviate more than 6 2°C (4°F) from the time of calibration to
V-1, V-2, V-3, and V-4 open, bake out the system (downstream
the termination of the test. T must either be within the range
a
of purifier to upstream of analyzer, exclusive of the exhaust
of 18 to 26°C (64 to 78°F) or be consistent with the analytical
leg) at 94°C (200°F) until outlet oxygen concentration is stable
systems manufacturer’s specifications, whichever is more
below <20 ppbv. Flow of the gas is specified in 7.4. Cool to
stringent.
lower T . Close valves V-1 and V-2.
s
7.4 The flow rate Q for components is 1 standard L/min
s
9.2 Baseline—Flowgasthroughtheteststandwiththespool
with 6 2 % tolerance.
piece installed on the test stand. Use the flow rate as defined in
7.5 The test gas shall be purified nitrogen or argon with a
7.4. Flow for 30 min after the oxygen concentration has
maximum oxygen concentration not exceeding an oxygen
attained a level of <20 ppbv. Utilizing heat tape, heat the spool
concentration of 10 ppb. Gas quality must be maintained at
piece and upstream tubing to within 80 mm of the upstream
flow specified in 7.4. The test gas must be passed through a
valve. Monitor the oxygen of the outlet and the T , as specified
s
filter having a pore size rating of 0.02 µm or finer. the filter
in 7.3. The time required to reach the higher T must be less
s
must be compatible with the 94°C (200°F) bake-out.
than or equal to 10 min. Continue testing for 30 min after a
stable baseline is reestablished (<20 ppbv) as specified in 9.1.
8. Preparation of Apparatus
Cool until the lower T is reached.
s
8.1 A schematic drawing of a recommended test apparatus
9.3 Place the spool piece, test component (in original
located inside a clean laboratory is shown in Fig. 1. Deviations
bagging), and fittings into a glove bag or nitrogen tent without
from this design are acceptable as long as baseline levels
disconnecting. Purge the glove bag with approximately five
consistent with 4.2.1 can be maintained. Nitrogen or argon gas
glove bag volumes of inert gas. Disconnect the spool piece
is purified to remove water and hydrocarbons. The base gas is
while maintaining the flow through the system. Maintain the
then filtered by an electronics grade, high purity, point of use
spool piece in the proximity of the positive flow. Reinstall the
filter (pore size rating ≤ 0.02 µm) before it is delivered to the
spool piece on the test stand. The entire disconnection and
test component.
reinstallation must be performed within 2 min. Maintain flow
8.2 A bypass loop may be used to divert gas flow through through the analyzer during disconnection and installation via
the test stand and the analyzer whenever the spool piece or a thebypassloop,usingvalvesV-1,V-2,V-3,andV-4(ifV-1and
testcomponentisinstalledorremovedfromtheteststand.This V-2 are open, then V-3 and V-4 will be closed). During
prevents the ambient air from contaminating the test apparatus
and the oxygen analyzer; thus, the analyzer baseline remains
the same. A glove bag is used to enclose test component lines
of the test apparatus during the installation and removal of the
spool piece and the test piece.
8.3 A trace oxygen analyzer capable of detecting oxygen
concentration levels down to 2 ppb is connected to the test
stand to sample the gas flowing through the test piece. The
purified and filtered base gas from the test stand containing <
10 ppb oxygen is used as the zero oxygen gas source for the
analyzer.Sincetheanalyzerissensitivetothesampleflowrate,
the metering valves within the analyzer should be adjusted to FIG. 2 Test Procedure Sequence
F1396 − 93 (2012)
disconnection, open valves V-1 and V-2 first, then close V-3
and V-4. After connection, reverse the order. Keep the purged
glove bag around each component for the duration of the test.
In th
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