INFICON MDC-260 Thin Film Deposition Controller - Manual (Page 114)

MDC-260 DEPOSITION CONTROLLER
SYSTEM INSTALLATION 9-2
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 OSCILLATORS
There are two sensor oscillators that may be used with the MDC-260, namely the
SO-100 and the VPLO-6. Both oscillators are designed to work with industry
standard 6-megahertz sensor crystals. Each 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-
260. This single coaxial cable provides both power for the oscillator and the
signal output for the controller. Cables of other lengths are available upon request
for replacing the 10’ cable.
9.3.1 SO-100 OSCILLATOR
The SO-100 sensor oscillator, Figure 9-3, is a simple, economical oscillator unit
designed to work with most simple metal film deposition processes. It contains
no intelligent.
9.3.2 VPLO-6 OSCILLATOR
The VPLO-6 sensor oscillator, Figure 9-4, has the phase lock loop technology
incorporated in its design. This allows the sensor crystals to achieve their
maximum life span. It also helps the rate stability in controlling the most
complex deposition processes. In addition, it has built-in intelligent that make
troubleshooting of installation problems effortless.
9.3.3 INSTALLATION
Connect one end of the 10-foot oscillator cable to the BNC connector on the
appropriate sensor input at the rear of the MDC-260. 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 INFICON to make the
connections. Failure to make these connections properly will result in the
impedance mismatch of the oscillator circuit.
9.4 INSTRUMENTATION FEEDTHROUGH
A 1 inch diameter, O-Ring sealed feedthrough (IF-111, Figure 9-5) 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