semi合集-English.pdf - 第3948页
12 Precision and Accuracy 12.1 Som e variance in Rou ghness Avera ge is to be expected on a single surf ace from measurem ent to measurement. No two measurem ents (as taken by different oper ators, on different in strume…
5.2.6 skidless a type of instrument that does not use
an external skid attached to the probe to act as a datum.
Instead, it references a datum plane internal to the
measurement equipment.
5.2.7 stylus the object which mechanically probes
the surface.
5.2.8 surface roughness the finer irregularities of
the surface texture, usually including those
irregularities that result from the inherent action of the
production process, for example traverse feed marks
from cutting tools [ASME B46.1-1995].
5.2.9 surface texture repetitive or random
deviations from the nominal surface that forms the
three-dimensional topography of the surface. Surface
texture includes roughness, waviness, lay, and flaws
[ASME B46.1-1995].
5.2.10 waviness the more widely spaced component
of surface texture. Waviness may result from such
factors as machine or workpiece deflections, vibrations,
chatter, heat treatment, or warping strains. Roughness
may be considered as superimposed on a “wavy”
surface.
6 Sampling
6.1 Acceptability criteria should be specified by the
user and be developed in accordance with published
sampling plans such as ASQ Z1.9, Sampling
Procedures and Tables for Inspection by Variables for
Percent Nonconforming.
7 Apparatus
7.1 The instrument should be a stylus type as defined
by ASME B46.1, Section 2. Due to the limitations of
skidded instruments (Type IV and V), a skidless
instrument (Type I) is preferable.
7.2 The instrument should be calibrated using standard
laboratory practices and manufacturer's
recommendations with a roughness metrology standard
calibrated by a certified testing laboratory and traceable
to NIST
3
.
7.3 In order to resolve the features of the surface, a
stylus with a conical tipped radius of 5 m (200 in)
should be used.
3 National Institute of Standards and Technology, 100 Bureau Drive,
Stop 3460, Gaithersburg, MD 20899-3460, (301) 975-6478,
http://www.nist.gov/
8 Units of Measure
8.1 Surface roughness should be described by means of
the Roughness Average, R
a
, as defined per ASME
B46.1.
8.2 Measurements should be specified in micro-meters
(m) or microinches (in).
9 Preparation of Apparatus
9.1 The surface should be clean and free from loose
debris before taking a measurement.
9.2 The instrument should be sufficiently isolated from
vibrations, which will artificially increase roughness
measurements.
9.3 Surfaces inaccessible to the stylus probe may be
exposed by sectioning a sample(s). Samples should be
sectioned to avoid damage to the surface to be
measured and should be cleaned appropriately to
remove sectioning debris.
10 Procedure
10.1 Select a single random location for measurement
within each distinct region of interest on each
component.
10.2 Measurements shall be taken perpendicular to the
lay. If this is not practical, measurements may be taken
in the direction of process gas flow through the
component.
10.3 Instrument cutoff length should be set to 0.800
mm (0.030 in.).
10.4 The evaluation length, or measurement length,
should be at least 3.81 mm (0.150 in.) where sufficient
length is available.
11 Reporting
11.1 Average R
a
is defined as the average of all R
a
measurements taken over a population.
11.2 Maximum R
a
is defined as the maximum of all R
a
measurements taken over a population.
11.3 Both Average R
a
and Maximum R
a
should be
reported for a given population. A population can be
defined as:
a set of single measurements on multiple
components
a set of multiple measurements on a single
component
a set of multiple measurements on multiple
components
SEMI F37-0299 © SEMI 1999, 2004 2
12 Precision and Accuracy
12.1 Some variance in Roughness Average is to be
expected on a single surface from measurement to
measurement. No two measurements (as taken by
different operators, on different instruments, or at
different locations on the surface of a component) will
contain the same data points. Because different
instruments will acquire data points at different rates,
and evaluation lengths may differ, a typical Roughness
Average measurement can include hundreds to tens of
thousands of data points. Reported measurements on
the same surface can be expected to deviate up to 20%.
13 Related Documents
13.1 ANSI Standard
4
Y14.36 Surface Texture Symbols
13.2 BSI Standard
5
BS 1134 Assessment of Surface Texture, Part 1:
Methods and Instrumentation and Part 2: Guidance and
General Information
13.3 DIN Standard
6
DIN 4768 Determination of Surface Roughness
Values R
a
, R
z
, R
max
with Electric Stylus Instruments
13.4 ISO Standard
7
ISO 4288 Rules and Procedures for the Mea-
surement of Surface Roughness Using Stylus
Instruments
13.5 JIS Standard
8
JIS B 0651 Instruments for the Measurement of
Surface Roughness by the Stylus Method
4 American National Standards Institute, Headquarters: 1819 L
Street, NW, Washington, DC 20036, USA. Telephone: 202.293.8020;
Fax: 202.293.9287, New York Office: 11 West 42nd Street, New
York, NY 10036, USA. Telephone: 212.642.4900; Fax:
212.398.0023, Website: www.ansi.org
5 British Standards Institution, 389 Chiswick High Road, London,
W4 4AL, United Kingdom, +44 (0)20 8996 9000, http://www.bsi-
global.com/
6 DIN Deutsche Institut für Normung, (DIN German Institut for
standardization e.V. ), Castle count road 6, 10787 Berlin, Germany,
+49 30 2601-0, +49 30 2601-1231, http://www2.din.de/
7 International Standards Organization, 1, rue de Varembé, Case
postale 56, CH-1211 Geneva 20, Switzerland, +41 22 749 01 11; Fax
+41 22 733 34 30, http://www.iso.org
8 Japanese Standards Association, 4-1-24 Akasaka Minato-ku,Tokyo
107-8440 Japan, +81-3-3583-8005, Fax: +81-3-3586-2014,
http://www.jsa.or.jp/default_english.asp
NOTICE: SEMI makes no warranties or
representations as to the suitability of the standards set
forth herein for any particular application. The
determination of the suitability of the standard is solely
the responsibility of the user. Users are cautioned to
refer to manufacturer's instructions, product labels,
product data sheets, and other relevant literature,
respecting any materials or equipment mentioned
herein. These standards are subject to change without
notice.
By publication of this standard, Semiconductor
Equipment and Materials International (SEMI) takes no
position respecting the validity of any patent rights or
copyrights asserted in connection with any items
mentioned in this standard. Users of this standard are
expressly advised that determination of any such patent
rights or copyrights, and the risk of infringement of
such rights are entirely their own responsibility.
Copyright by SEMI® (Semiconductor Equipment and Materials
International), 3081 Zanker Road, San Jose, CA 95134. Reproduction of
the contents in whole or in part is forbidden without express written
consent of SEMI.
SEMI F37-0299 © SEMI 1999, 2004 3
SEMI F38-1104 © SEMI 1999, 2004 1
SEMI F38-0699 (Reapproved 1104)
TEST METHOD FOR EFFICIENCY QUALIFICATION OF POINT-OF-USE
GAS FILTERS
This test method was technically reapproved by the Global Gases Committee and is the direct responsibility
of the North American Gases Committee. Current edition approved by the North American Regional
Standards Committee on August 16, 2004. Initially available on www.semi.org September 2004; to be
published November 2004. Originally published June 1999.
1 Purpose
1.1 The purpose of this document is to define a
comprehensive standard test sequence to qualify the
particle filtration efficiency achievable using Point-of-
Use (POU) gas filters.
2 Scope
2.1 This test method defines an evaluation method for
Point-of-Use filters of various media (e.g., metallic,
ceramic, and polymeric) typically used for filtering
inert and process gases in semiconductor applications.
Point-of-Use filters are designed to handle relatively
low flow rates (0.5 – 50 slm.) and moderately high
pressure drops. The filter housing and filtration
element are combined into one sealed and inseparable
unit.
2.2 This test method is intended to demonstrate the
ability of a Point-of-Use gas filter to equal or exceed a
specific particle filtration efficiency class when
challenged with a monodispersed aerosol in the size
range described in Section 6.6.
2.2.1 The efficiency class of the test method is defined
as the log reduction value (LRV), where LRV is the
Log [Input Concentration/System Background Level].
NOTICE: This standard does not purport to address
safety issues, if any, associated with its use. It is the
responsibility of the users of this standard to establish
appropriate safety and health practices and determine
the applicability of regulatory or other limitations prior
to use.
3 Limitations
3.1 These test methods do not apply to gas filter
cartridges.
3.2 These test methods do not apply to bulk gas filters.
3.3 The various media (e.g., metallic, ceramic, and
polymeric) may have slightly different critical particle
sizes (most penetrating particle sizes). Therefore, many
challenge tests have to be performed over a range of
particle sizes to assure that the “worst case” challenge
has been performed.
3.4 The efficiency test is for steady state flow and
room temperature only. Comparison to efficiency in
pulsed flow, elevated temperature etc., will have to be
developed separately.
3.5 Statistical evaluation on the variability in efficiency
of a media type should be done with a valid sample
size. This evaluation is not within the scope of this test
method.
3.6 The upper concentration limit of the CNC as
specified by the manufacturer should not be exceeded.
Exceeding the CNC concentration will understate the
challenge concentration due to coincidence counting,
thus affecting filter efficiency calculations.
3.7 This is not intended as a method for precise
determination of filter efficiency. It is intended as a
means for determining if a filter has an efficiency equal
to or better than an approximate nominal value.
3.8 Commercially available radioactive neutralizers
have pressure limitations. Users should be aware of
these limits.
4 Referenced Standards
4.1 None.
5 Summary of Method
5.1 The test sequence consists of three steps:
5.1.1 Static background with filter.
5.1.2 Filter challenge with first monodispersed particle
size (see Section 6.6 for particle size test sequence).
5.1.3 Filter challenge with subsequent monodispersed
particle sizes.
6 Apparatus and Facility
6.1 Gas Source — Clean, dry gas (nitrogen or air) with
less than 0.5 ppm moisture and less than 0.5 ppm total
hydrocarbons.
6.2 Particle Detector — A condensation nucleus
counter (CNC) with a counting efficiency of 50% at
0.01 micron, as reported by the manufacturer, is
recommended to measure total particle concentration of
particles greater than 0.01 micron. The CNC must meet