INFICON MDC-360C Thin Film Deposition Controller - Manual (Page 127)

MDC-360C DEPOSITION CONTROLLER
SYSTEM INSTALLATION 9-3
Removal and replacement of sensor crystals should be performed in a clean
environment. An isolated clean workbench is recommended for crystal
replacement.
9.5.1 CRYSTAL CARE AND HANDLING
It is essential that a sensor crystal is clean and free of contamination that
undermine the quality of the crystal inducing errors in the measurements or
shortening its useful life. The following guidelines are recommended for general
handling of the sensor crystals.
‹ Keep the crystals in a clean environment. Store them in their original
package until use.
‹ Never handle the crystals with bare hands.
‹ Always use plastic tweezers around the edge of the crystal during handling.
‹ Do not touch the center of a sensor crystal, as any oil, dirt, dust, or scratches
will quickly degrade the quality of the crystal.
‹ When using a chemical agent to clean the crystal, ensure that the crystal
electrode material(s) will not be damaged by the chemical.
‹ Never use cleaner that will etch the quartz surface.
‹ Always rinse with deionized water, or another appropriate pure liquid,
before drying the crystal.
‹ Always use a flow of dry, oil-free, non-reactive gas (e.g. filtered nitrogen) to
blow-dry the crystal. It is better to chase liquid off the crystal than to let it
evaporate off the crystal.
‹ Never wipe the crystal – even soft, lint-free cloth will scratch the crystal.
‹ When handling the drawer always hold it by the edges to avoid touching the
crystal surface.
9.5.2 CRYSTAL REPLACEMENT PROCEDURE
1. Using your thump and index fingers, gently squeeze the sides of the retainer at
mid section then lift it up, away from the drawer, as shown in Figure 9-1.
2. Holding the drawer by the handle and turn it up side down to remove the spent
crystal.
3. Install a new crystal in the drawer. Observe its orientation. The pattern
electrode should face upward as shown in Figure 9-2.
4. Hold the retainer by its sides. Align its orientation notch with the drawer then
gently and evenly push the retainer down until it snaps firmly into the drawer.
See Figure 9-2. Never push down (or pull up) on the contact spring, doing so
may permanently damage it.
5. Inspect the whole assembly. The retainer should lie evenly and engage the
drawer at all of the four corners.