INFICON STC-2000A Thin Film Deposition Controller Operating Manual - Manual (Page 36)

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STC-2000A DEPOSITION CONTROLLER
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crystal connection are on the other side of the thick metal disc (places the 3 terminations outside the
chamber). The electrical connection is terminated with a standard male BNC connector. The "bakeable"
unit, therefore, presents itself on the outside of the flange like the standard crystal sensor. The so-called
"Dual Shuttered Head" has 2 crystal sensors in tandem on a single assembly. As part of the assembly, a
shutter always covers one crystal while exposing the other. When the shutter moves it exposes the
formerly covered crystal and covers the formerly exposed crystal. The installation of a dual shuttered
sensing head is similar to that of the single head. A second sensing input (Sensor 2) is used on the second
crystal channel. Automatic crystal switching by shutter is accomplished by I/O programming. The primary
crystal sensor channel (Channel 1 in this example) has an associated shutter control bit weight value
accessed through I/O programming (ID#81). The primary crystal sensor channel (Channel 1 in this
example) and the secondary crystal sensor channel (CH
annel 2 in this example) are set to the active state by
menu programming. By opening or closing the shutter associated with the primary crystal sensor channel
(Channel 1 in this example), the I/O programming performs the necessary functions for controlling the
shutter of the dual sensor. Proper phasing between the sensor inputs and shutter control can easily be
checked by installing a sensing crystal in only sensor 1 and observing the good and "failed" (absent)
sensing crystal when switching manually between sensor 1 (good) and sensor 2 (failed).
Of course this mechanical method can be supplemented by using 2 sensors without shutters. The primary
crystal sensor channel (Channel 1 in this example) and the secondary crystal sensor channel (CH
annel 2 in
this example) can also be selected by I/O programming commands or the active sensor can have a backup
crystal sensor channel list that names channel 2 (or the secondary sensor channel) as the automatic
replacement for the failed primary channel. (Sequence would be: fail primary [by command or 3
rd STATUS
menu], backup list provides secondary, re-verify [by command or 3 rd STATUS menu] reinstates the
primary.)
Power Supply Connection: This refers to the high current (or voltage) power supply that provides the
energy to create the evaporant stream. The power supply connection on the STC-2000A has the control
voltage that controls the high current (or voltage) power supply. From the STC-2000A point of view, this
is known as the source control voltage. The word source describing the source material of the deposition
process in the form of an evaporant stream. Along the bottom of the back panel, in the area where the
sensor card is expected to reside, is the text label SOURCE. This is meant to indicate the 9 pin D-sub
connector that is part of the sensor card. The text label, ½, refers to control voltage outputs. In the sensor
card slot, this indicates control voltage 1 and control voltage 2. Control voltage 1 can be used to control the
high current (or voltage) power supply just described. The 2
nd control voltage could alternately be used to
control the high current (or voltage) power supply but is typically used for the strip chart recorder control.
These identical analog outputs can be interchanged. In fact, their function is assigned by means of menu
programming. If the two functions (control voltage and recorder) are assigned by menu programming on
the same analog channel, the control voltage will have precedence and the recorder function will be lost.
After these programmed outputs are used in a film, a conflicting recorder function having been lost in this
way would require a reboot to recognize a correcting change. The analog output used for the control
voltage output has a number of programmable parameters associated with it. One in the MAIN/ REVIEW
FILMS menu path is: SS MAP SELECT. Another one in the MAIN/ REVIEW MAPS menu path is: source
out channel. Don't overlook the ground connection (connector shell). Shielding goes a long way toward
noise reduction and ultimately contributes to a stable system. [Section 4.6 has more details]
Strip Chart Recorder Connection: This refers to the STC-2000A output from the 9 pin D-sub on the
sensor card that can provide the proper analog signal for a strip chart recorder. Along with the hardware
connection, the analog output used for the strip chart recorder has a number of programmable parameters
associated with it. Two in the MAIN/ EXEC/ SYSTEM CONFIG menu path are: recorder function I/O
control and recorder out channel. This function can be assigned to one or none of the 2 identical source
out channels. Don't overlook the ground connection (connector shell). Shielding goes a long way toward
noise reduction and ultimately contributes to a stable system. (See Power Supply Connection above for
other source out channel details) [Section 4.7 has more details]
SECTION 2.XX page 36 of 292