INFICON MDC-360 Thin Film Deposition Controller - Manual (Page 114)

MDC-360 DEPOSITION CONTROLLER
9-2 SYSTEM INSTALLATION
Use a shutter to shield the sensor during initial soak periods to protect the crystal
from any sputtering that may occur. If a small droplet of molten material hits the
crystal, the crystal may be damaged and oscillation may cease.
9.3 SENSOR OSCILLATOR
The sensor oscillator, Figure 9-2, is designed to be used with industry standard 6
megahertz sensor crystals. The oscillator’s characteristics enable it to obtain
maximum life from the sensor crystal.
The oscillator is supplied with a 6” coaxial cable and a 10’ coaxial cable. The 6”
cable interconnects the oscillator and the feedthrough. The 10’ cable
interconnects the oscillator and the MDC-360. This single coaxial cable provides
both power for the oscillator and the signal output for the controller. Cables of
any length are available upon request for replacing the 10’ cable. A schematic of
the oscillator is shown on Figure 9-1.
9.3.1 INSTALLATION
Connect one end of the 10-foot oscillator cable to the BNC connector on the
appropriate source-sensor board at the rear of the MDC-360. Connect the other
end of the cable to the oscillator with the arrow pointed toward the sensor head.
The oscillator connects to the feedthrough leading into the vacuum chamber using
a 6 in. cable.
CAUTION
Always use the cables supplied by Maxtek to make the connections.
Failure to make this connection correctly
will create a mismatch in the impedance
of the oscillator circuit.
9.4 INSTRUMENTATION FEEDTHROUGH
A 1 inch diameter, O-Ring sealed feedthrough (IF-111, Figure 9-3) or a 2-3/4 inch
Conflat® flange seal are available with 1/8 inch source and return water cooling
lines, and internal and external coaxial cable connectors. Base plate thickness up
to one inch can be accommodated.
RF interference and free electrons are effectively shielded from the signal
connector through the use of fully closed coaxial cable connections. A standard
coaxial cable with a Microdot® S-50 connector mates the internal feedthrough
connector to the sensor head. The feedthrough has a standard BNC connector for
the coaxial connection to the sensor oscillator.
9.5 SENSOR CRYSTAL REPLACEMENT
The Sensor Head is especially designed for easy sensor crystal replacement and
reliable operation. The crystal lies in a drawer that slides into the sensor housing.
Pull the drawer straight out of the sensor housing by gripping the drawer’s edges
e drawer removed, pull straight up on the
ent crystal. Drop a new crystal into the
between thumb and forefinger. With th
retainer spring clip and shake out the sp