semi合集-English.pdf - 第475页

SEMI E67-0304 © SEMI 1997, 2004 10 n φ r φ pÆ 0.005 0.01 0.025 0.05 0.1 0.5 0.9 0.95 0.975 0.99 0.995 9 3 -11.84 -8.048 -5.062 -3.693 -2.704 -1.312 -0.739 -0.551 -0.304 0.209 0.744 9 4 -6.562 -5.165 -3.775 -3.043 -2.457 …

SEMI E67-0304 © SEMI 1997, 2004 9

# of cycles to 50% failure = 3000 from grap

* = LOG (# of cycles to 50% failure)

* = LOG (30000)

* = 4.477

# of cycles to 16% failure = 11000 from graph

* − LOG (# of cycles to 16% failure)

* = 4.477 − LOG (11000)

* = 4.477 − 4.041

* = 0.436

A1-1.1.7 From Table A1 (from page 272 of Nelson’s book), look up t*:

This data indicates, with a 90% confidence limit, that 10% of the devices will fail by 2443 cycles.

A1-1.1.8 Table A1 percentiles t* (d: 10, n, r) for limits for y

.10

pÆ 0.005 0.01 0.025 0.05 0.1 0.5 0.9 0.95 0.975 0.99 0.995

2 2 -183.9 -88.09 -36.3 -16.4 -7.869 -1.405 -0.327 -0.118 0.083 0.444 0.888

3 2 -117.6 -59.41 -26.14 -13.45 -6.786 -1.38 -0.495 -0.256 -0.0715 0.898 2.072

3 2 -17.6 -12.28 -7.761 -5.497 -3.691 -1.326 -0.473 -0.305 -0.154 0.047` 0.172

4 2 -113.5 -56.59 -21.5 -11.55 -5.934 -1.348 -0.537 -0.28 0.236 1.864 4.305

4 3 -15.58 -11.52 -7.112 -5.071 -3.503 -1.313 -0.558 -0.399 -0.252 -0.0573 0.107

4 4 -9.617 -7.008 -4.985 -3.792 -2.921 -1.29 -0.559 -0.409 -0.265 -0.124 -0.0141

5 2 -112.9 -48.61 -18.13 -9.49 -4.988 -1.322 -0.567 -0.182 0.519 2.436 5.585

5 3 -13.33 -9.911 -6.294 -4.598 -3.208 -1.306 -0.622 -0.463 -0.285 -0.00405 0.271

5 4 -7.956 -6.415 -4.652 -3.636 -2.778 -1.292 -0.624 -0.475 0.335 -0.173 -0.0587

5 5 -5.565 -4.871 -3.892 -3.184 -2.585 -1.287 -0.622 -0.472 -0.344 -0.202 -0.109

6 2 -76.15 -37.64 -17.14 -8.573 -4.669 -1.313 -0.57 -0.0928 0.779 3.427 6.336

6 3 -14.2 -10.33 -6.289 -4.393 -3.107 -1.303 -0667 -0.503 -0.323 -0.0332 0.375

6 4 -7.414 -5.87 -4.386 -3.487 -2.721 -1.302 -0.673 -0.546 -0.427 -0.286 -0.197

6 5 -5.45 -4.681 -3.746 -3.083 -2.498 -1.297 -0.673 -0.547 -0.44 -0.309 -0.219

6 6 -4.663 -4.012 -3.336 -2.826 -2.371 -1.3 -0.678 -0.546 -0.438 -0.322 -0.246

7 2 -68.12 -32.41 -15.19 -8.208 -4.34 -1.303 -0.561 -0.016 0.989 4.067 9.64

7 3 -12.82 -9.162 -5.602 -4.099 -3.005 -1.301 -0.71 -0.529 0.33 -0.0654 0.292

7 4 -7.571 -5.812 -4.171 -3.346 -2.622 -1.298 -0.722 -0.587 -0.464 -0.289 -0.12

7 5 -5.523 -4.604 -3.705 -3.034 -2.417 -1.295 -0.723 -0.595 -0.495 -0.361 -0.243

7 6 -4.636 -4.112 -3.351 -2.791 -2.32 -1.288 -0.722 -0.597 -0.501 -0.381 -0.294

7 7 -4.282 -3.693 -3.041 -2.641 -2.228 -1.285 -0.725 -0.595 -0.501 -0.376 -0.287

8 2 -63.58 -29.95 -13.34 -6.948 -3.728 -1.293 -0.472 0.226 1.645 6.157 14.5

8 3 -10.54 -7.628 -4.967 -3.637 -2.756 -1.297 -0.732 -0.549 -0.309 0.13 0.54

8 4 -6.59 -5.172 -3.937 -3.119 -2.484 -1.286 -0.752 -0.609 -0.468 -0.266 -0.11

8 5 -5.363 -4.296 -3.443 -2.885 -2.361 -1.287 -0.757 -0.629 -0.507 -0.358 -0.242

8 6 -4.515 -3.855 -3.22 -2.756 -2.282 -1.287 -0.758 -0.633 -0.514 -0.386 -0.306

8 7 -4.086 -3.583 -3.019 -2.602 -2.205 -1.284 -0.755 -0.632 -0.514 -0.399 -0.336

8 8 -3.781 -3.414 -2.851 -2.485 -2.162 -1.29 -0.757 -0.63 -0.514 -0.404 -0.338

9 2 -56.28 -30.29 -11.44 -6.353 -3.55 -1.314 -0.465 0.353 2.089 6.581 11.57

SEMI E67-0304 © SEMI 1997, 2004 10

pÆ 0.005 0.01 0.025 0.05 0.1 0.5 0.9 0.95 0.975 0.99 0.995

9 3 -11.84 -8.048 -5.062 -3.693 -2.704 -1.312 -0.739 -0.551 -0.304 0.209 0.744

9 4 -6.562 -5.165 -3.775 -3.043 -2.457 -1.31 -0.772 -0.64 -0.505 -0.3 -0.167

9 5 -5.034 -4.316 -3.446 -2.851 -2.318 -1.307 -0.777 -0.66 -0.548 -0.427 -0.326

9 6 -4.437 -3.901 -3.21 -2.714 -2.232 -1.305 -0.779 -0.663 -0.566 -0.444 -0.365

9 7 -4.103 -3.651 -3.08 -2.605 -2.177 -1.303 -0.78 -0.665 -0.57 -0.457 -0.373

9 8 -3.813 -3.408 -2.878 -2.49 -2.135 -1.3 -0.776 -0.665 -0.572 -0.459 -0.381

9 9 -3.624 -3.228 -2.752 -2.413 -2.067 -1.298 -0.78 -0.666 -0.571 -0.458 -0.396

10 2 -60.81 -27.39 -10.07 -5.683 -3.326 -1.299 -0.34 0.77 2.744 7.973 15.67

10 3 -9.675 -6.99 -4.618 -3.42 -2.572 -1.301 -0.758 -0.532 -0.255 0.306 1.018

10 4 -6.389 -5.028 -3.792 -2.993 -2.353 -1.297 -0.798 -0.657 -0.528 -0.332 -0.134

10 5 -5.258 -4.324 -3.357 -2.749 -2.257 -1.297 -0.801 -0.684 -0.581 -0.426 -0.315

10 6 -4.559 -3.701 -3.029 -2.569 -2.182 -1.294 -0.802 -0.689 -0.59 -0.488 -0.405

10 7 -3.838 -3.43 -2.853 -2.497 -2.121 -1.293 -0.803 -0.689 -0.593 -0.497 -0.428

10 8 -3.706 -3.173 -2.752 -2.401 -2.091 -1.292 -0.803 -0.688 -0.598 -0.502 -0.431

10 9 -3.458 -3.118 -2.636 -2.353 -2.046 -1.288 -0.804 -0.689 -0.598 -0.502 -0.438

10 10 -3.297 -2.996 -2.561 -2.284 -2.02 -1.29 -0.804 -0.693 -0.598 -0.501 -0.437

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SEMI E68-0997 © SEMI 1997, 2003 1

SEMI E68-0997 (Reapproved 1103)

TEST METHOD FOR DETERMINING WARM-UP TIME OF MASS FLOW

CONTROLLERS

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 July 27, 2003. Initially available at www.semi.org October 2003; to be published

November 2003. Originally published September 1997.

1 Purpose

1.1 The purpose of this method is to provide a

standardized method for quantifying the warm-up time

of an MFC.

NOTE 1: Warm-up times affect the initial performance of a

mass flow controller (MFC). Warm-up time is necessary

information in deciding if a process tool is ready to be put

back into service. In addition, warm-up data will be useful in

calibration labs.

2 Scope

2.1 The test conditions in this method are intended to

simulate bench top warm-up, with an MFC that has

been equalized to ambient conditions for 24 hours

before the application of power.

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 Conditions in the lab may be different from

conditions found in the field and may influence test

results. This test is intended to measure warm-up under

a controlled condition.

3.2 The MFC is to be at ambient temperature before

the beginning of the test.

3.3 Due to manufacturing variability, warm-up times

may vary for the same model of MFC. This

specification addresses a method for taking a single

data point repetitively from the same MFC. Resulting

data will show exactly how warm-up effects change the

delivered flow of that particular MFC. To statistically

quantify warm-up time for a particular model of MFC,

multiple samples should be tested.

4 Referenced Documents

None.

5 Terminology

5.1 Abbreviations and Acronyms

5.1.1 DUT — Device under test

5.1.2 FS — Full scale

5.1.3 MFC — Mass flow controller

5.2 Definitions

5.2.1 device under test — the MFC being tested for

warm-up time.

5.2.2 indicated flow — flow indicated by the MFC

under test. Electrical output of the DUT.

5.2.3 stability — a condition that exhibits only natural,

random variations in the absence of unnatural,

assignable-cause variations. For the several purposes of

this test, stability is defined as ± 10% of the accuracy of

the DUT at full scale.

5.2.4 steady state — state at which the indicated flow

is stable for a 15-minute time period.

5.2.5 warm-up — a process where the MFC goes from

an unpowered condition to a condition where the output

is within ± 1% full scale, of the final steady state output.

6 Summary of Test Method

6.1 The DUT is connected in series with shut-off

valves on either side of the DUT. With no gas flow and

the DUT powered, indicated flow is monitored until

steady state is achieved. Power is briefly disconnected

then reconnected and indicated flow is again monitored

until steady state is achieved.

7 Significance and Use

7.1 Data generated by this method is used to estimate

the amount of time an MFC should be powered up in a

process tool before resuming production. When

calibrating an MFC, the warm-up time can be used to

estimate the waiting time before calibration. For power

interruptions, the power interruption warm-up time may

be used to determine the time required following a

power interruption to resume production or calibration.