Minus K Technology

 

Curve Criterion Amplitude1
μm/s (μin/s)

Detail Size2
μm

Description of Use
Workshop (ISO)
800( 32,000)
N/A
Distinctly perceptible vibration. Appropriate to workshops and non-sensitive areas.
Office (ISO)
400 (16,000)
N/A
Perceptible vibration. Appropriate to offices and non-sensitive areas
Residential Day (ISO)
200 (8000)
75
Barely perceptible vibration. Appropriate to sleep areas in most instances. Usually adequate for computer equipment, hospital recovery rooms, semiconductor probe test equipment and microscopes less than 40x.
Op. Theatre (ISO)
100 (4000)
25
Vibration not perceptible. Suitable in most instances for surgical suites, microscopes to 100X and for other equipment of low sensitivity.
VC-A
50 (2000)
8
Adequate in most instances for optical microscopes to 400X, microbalances, optical balances, proximity and projection aligners, etc.
VC-B
25 (1000)
3
Appropriate for inspection and lithography (including steppers) to 3 μm line widths..
VC-C
12.5 (500)
1 - 3
Appropriate standard for optical microscopes to 1000X, inspection and lithography inspection equipment (including moderately sensitive electron microscopes) to 1 μm detail size, TFT-LCD stepper/scanner processes.
VC-D
6.25 (250)
0.1 - 0.3
Suitable in most instances for the most demanding equipment including electron microscopes (TEMs and SEMs) and E-Beam systems..
VC-E
3.12 (125)
< 0.1
A challenging criterion to achieve. Assumed to be adequate for the most demanding of sensitive systems including long path, laser-based, small target systems, E-Beam lithography systems working at nanometer scales, and other systems requiring extraordinary dynamic stability.
VC-F
1.56 (62.5)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
VC-G
.78 (31.3)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
NIST-A
NIST-A criterion is identical to the VC-E curve at frequencies above 20 Hz, but maintains constant displacement at frequencies below this. 0.025 μm or 25 nm between 1 and 20 Hz; 3.1 μm /s (125 μ in /s) between 20 and 100 Hz
NIST-A1
NIST-A1 criterion requires an RMS velocity of 3 μm/sec (118 μin./sec) for frequencies less than 4 Hz, and 0.75 μm/sec (29.5 μin./sec) velocity for frequencies 4 Hz < f < 100 Hz
VC-H
.39 (15.63)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
VC-I
.195 (7.81)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
VC-J
.097 (3.9)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
VC-K
.048 (1.95)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
VC-L
.024 (0.98)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
VC-M
.012 (0.49)
N/A
Appropriate for extremely quiet research spaces; generally difficult to achieve in most instances, especially cleanrooms. Not recommended for use as a design criterion, only for evaluation.
1As measured in one-third octave bands of frequency over the frequency range 8 to 80 Hz (VC-A and VC-B) or 1 to 80 Hz (VC-C through VC-G)
2The detail size refers to line width in the case of microelectronics fabrication, the particle (cell) size in the case of medical and pharmaceutical research, etc. It is not relevant to imaging associated with probe technologies, AFMs, and nanotechnology.
The information given in this table is for guidance only. In most instances, it is recommended that the advice of someone knowledgeable about applications and vibration requirements of the equipment and processes be sought.
This table is a reference of Colin Gordon Associates ,except (3&4).3Vibro-Acoustic Consultants,4Purdue University Libraries.