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SEMI F43-0699 © SEMI 1999 5 permanent l y crimp any ferrul es onto the tube stu bs. Nylon ferrules are acceptable. 7.3.2.3 Us ing t he fl ow control device, s e t the test flow to manufactu rer ’s recommended max i mum f…

SEMI F43-0699 © SEMI 1999 4

components used for the construction of the

recommended test apparatus are given because they have

been found to be critical to the proper operation of the

test apparatus as required by the specification.

Deviations from these dimensions have resulted in some

lab facilities not meeting the requirements of the

specification.

7.2.3.2 The spool piece is to be installed when the test

stand is not in use. A continuous low flow (0.1 scfm) is

to be maintained to purge the system. The particle

counter may be turned off. For an extended shutdown,

the system (excluding the CNC) should be pressurized

and capped.

7.2.3.3 After initial construction, the spool piece

should be installed and the test apparatus (except the

CNC) should be pressurized and tested for leaks in the

system. It is recommended that a helium leak detector

or a pressure decay method be used to detect leaks in

the system. The system should then be cleaned by

running a high flow rate of test gas with simultaneous

gentle tapping of all components (except the CNC)

downstream of the final filter F3. This procedure

should be followed by a start-up phase which

characterizes system cleanliness by conducting the

entire test protocol with the control product installed.

This start-up phase should continue and be repeated as

necessary until the counts from the control product have

stabilized at or below the expected number of counts

from the test components.

7.3 Test Procedures

NOTE: Ensure the counter is counting continuously

and reporting data every minute. For the duration of

the test, the counter should be continuously counting,

except where noted in the test protocol.

7.3.1 Background Test

7.3.1.1 Ensure that the spool piece and proper adapters

are in place on the test apparatus.

7.3.1.2 Static Test  Close the pneumatic valve

(PV1). Set regulator R1 to 30 psig. Open the

pneumatic valve (PV1) to establish flow. Using the

flow control device, set the test flow to manufacturer’s

recommended maximum flow. Measure the static

background count. Background count is established

when the counter has sampled a minimum of 3 scf, and

the arithmetic average during the last 3 scf of gas

sampled is <2 particles/scf. At a sample flow rate of

0.05 scfm, the time required is one hour. Ensure that

the background counts are stable or decreasing. If

background cannot be achieved after 6 scf have been

sampled, there may be a problem with the counter or

test apparatus.

7.3.1.3 Dynamic Test  Set the actuator pressure of

PV1 to its minimum pressure recommended by the

manufacturer to fully open the valve. Actuate the

pneumatic valve PV1 at 30 cycles per minute to

measure the background counts under dynamic test

conditions. Dynamic background count is established

when the counter has sampled a minimum of 3 scf, and

the arithmetic average during the last 3 scf of gas

sampled is < 3 particles/scf. (Estimated dynamic

background count will be verified and altered if

necessary during the validation phase of this test

method.) At a sample flow rate of 0.05 scfm, the time

required is 1 hour. If dynamic background cannot be

achieved after 6 scf have been sampled, there may be a

problem with the counter or test apparatus.

7.3.1.4 Stop the pneumatic valve cycling. Flush the

system for 10 minutes under static test conditions.

7.3.1.5 Purifier Impact Test  Impact the spool piece

once per minute for ten minutes with the mechanical

shock device (See Figure 2). The impact background

count should be <4 particles/scf over the ten minutes of

the test. (Estimated impact background count will be

verified and altered if necessary during the validation

phase of this test method.) If impact background

cannot be achieved, repeat the shock a second time. If

the impact background count specification still cannot

be met, there may be a problem with the counter or test

apparatus.

7.3.1.6 Flush the system for 30 minutes at the test flow

rate. Record the resulting count.

7.3.1.7 Turn the CNC pump off while leaving the

CNC power on.

7.3.2 Purifier Static Test

7.3.2.1 Using the flow control device, decrease the

flow rate to 0.1–0.2 scfm, so that some flow remains in

the system while the test purifier is installed.

7.3.2.2 Remove the spool piece by first disconnecting

the downstream fitting and then the upstream fitting.

Immediately install the test component in a fully open

position by first connecting the upstream fitting and

then the downstream fitting. Removal of the spool

piece and installation of the test component to minimize

reactions of the purifier with room air and extraneous

contamination and prevent the counter from cooling off

should take no longer than 3 minutes. Extreme care

should be taken to minimize contamination of the test

apparatus during this operation. The test component is

to be removed from its inner bag in the Class 100 test

area. If the test component has mechanical fittings,

these fittings are to be properly connected. If the test

component has tube ends, the component is to be

installed with clean compression fittings. Do not

SEMI F43-0699 © SEMI 19995

permanently crimp any ferrules onto the tube stubs.

Nylon ferrules are acceptable.

7.3.2.3 Using the flow control device, set the test flow

to manufacturer’s recommended maximum flow.

7.3.2.4 Turn on the counter pump and conduct the

static test. The purifier is to be tested with the valve

PV1 in the fully open position until 85 standard liters (3

scf) of gas have been sampled. Cumulative data should

be recorded at one-minute intervals.

7.3.3 Purifier Dynamic Test

7.3.3.1 This test is to immediately follow the static

test. To conduct the dynamic test, set the actuator

pressure of the actuator attached to valve PV1 to its

minimum actuator pressure as recommended by the

manufacturer to fully open the valve. Actuate valve

PV1 at the rate of 30 cycles/minute for 60 minutes. A

cycle consists of off and on actuation of the valve. The

off and on cycles should be of equal duration.

7.3.4 Purifier Impact Test

7.3.4.1 This test is to immediately follow the dynamic

test. Maintain the test flow rate for 10 minutes, with

the valve PV1 in the fully open position. Impact the

purifier once a minute for 10 minutes, using the

mechanical shock device. Purge the test component by

maintaining the test flow rate for 30 minutes.

7.3.5 Turn the counter pump off and then decrease the

test gas flow rate to ~ 5 slpm.

7.3.6 Remove the test purifier by first disconnecting

the downstream fitting and then the upstream fitting,

and immediately install the spool piece by connecting

the upstream fitting followed by the downstream fitting.

The removed purifier should be immediately valved off

or capped to prevent its exposure to room air.

7.4 Data Presentation

7.4.1 The following test conditions are to be reported

in the data presentation:

• Date and time of test

• Operator

• Test flow rate (scfm)

• Test pressure (psig)

• Test temperature (°C)

• Purifier type, manufacturer, serial number, lot

number, and model number

• CNC manufacturer, serial number, sample flow

rate (scfm), model number, and calibration date

• Test gas type and dew point (°C)

• A schematic of the test apparatus, including

manufacturer's and model numbers of all test

apparatus components

• Calibration dates for the flow meters and the test

date

7.4.2 Graph the static, dynamic and impact portions

of the test separately as counts/minute (measured by the

counter) versus time, including the appropriate

background (measured with the spool piece in place)

with each. Also graph the entire data set as counts per

minute versus time. If different filters are to be

compared, graph their entire data sets together.

7.4.3 Present the entire raw data set in tabular form.

8 Related Documents

8.1 The appropriate particle counter manufacturer's

operating and maintenance manuals should be consulted

when using this test method.

8.2 On particle counter efficiencies: Agarwal, J. K.

and Sem, G. J. "Continuous Flow, Single Particle

Counting Condensation Nucleus Counter." Journal of

Aerosol Science, v.11.4. July 1980:343–357.

8.3 On flow calculations: D. E. Dickie, ed. Crane

Handbook. Construction Safety Association of Toronto.

Ontario, Canada. 1975.

8.4 Statistical reference: Van Slooten, R. A.,

"Statistical Treatment of Particle Counts in Clean

Gases. " Microcontamination, v.4.2. Feb. 1986:32–38.

8.5 Hinds, W. C. Aerosol Technol ogy: Properties,

Behavior, and Measurement of Airborne Particles. John

Wiley & Sons. 1982:187–194.

8.6 Fissan, H. and Schwientek. "Sampling and

Transport of Aerosols." TSI Journal of Particle

Instrumentation, v.2.2. July–December 1987:3–10.

8.7 SEMI F1-96, Specification for Leak Integrity of

High Purity Gas Piping Systems and Components.

Gas

Inlet

FM1

FM2

PV1

Test

Purifier

Exhaust

F1 = 10" PTFE Membrane Filter

R1 = @ 0-100 psig Outlet Regulator

P1, P2 = Electronics Grade Pressure Gauge (30"-0-60)

V1 = Three-Way Valve

FM1 = Low Flow (0-2 scfm) Flowmeter

FM2 = High Flow (0-20 scfm) Flowmeter

F2, F3 = Electronics Grade Filter

PV1 = Electronics Grade Pneumatic Valve

Figure 1

Schematic of Particle Test Loop