INFICON Sputtering Sensor - Manual (Page 45)

4 - 5
IP
N 07
4-
15
7L
Sputtering Crystal Sensor Operating Manual
6 Use both pliers to form a new transition point according to Figure 4-3 -b, thus
returning the spring to a shape similar to the solid line delineation of
Figure 4-3 -c.
7 Reinstall the spring into the groove provided in the crystal cavity.
8 Determine if the retention force is acceptable and that the wire does not impede
crystal insertion. Repeat these instructions if unacceptable retention forces
persist.
4.4 Crystal Holder Maintenance
In dielectric coating applications, the surface where the crystal contacts the crystal
holder may require periodic cleaning. Since most dielectrics are insulators, any
build-up due to blow-by will eventually cause erratic or poor electrical contact
between the crystal and the sensor body. This build-up will also cause a reduction
in thermal transfer from the crystal to the sensor body. Both of these will result in
noisy operation and early crystal failure.
Cleaning may be accomplished by gently buffing the crystal holder to crystal
seating surface with a white Scotch-Brite™ pad followed by an ultrasonic bath in
soap solution followed by thorough rinsing in deionized water and drying or by
ultrasonic cleaning and rinsing only.
NOTE: The crystal holder seating surface is machined to a very fine finish (16
micro inches rms). This high quality finish is essential to provide good
electrical and thermal contact with the crystal. Applying excessive force
during cleaning or using overly abrasive cleaning materials may damage
this finish and reduce sensor performance.
4.5 Sputtering Sensor Shutter Maintenance
The sensor shutter should be dismantled approximately every 2000 strokes for
lubrication with molybdenum disulfide in alcohol (IPN 750-191-G1) or equivalent in
the areas specified on
Figure 1-6 on page 1-10 . Failure to lubricate may
significantly reduce life of operation or cause the assembly to become totally
inoperative.