INFICON STC-2002 Thin Film Deposition Controller Operating Manual - Manual (Page 23)

p STC-2002 DEPOSITION CONTROLLER y
SECTION 2.XX e page 21 of 276 ^
SIMPLE QUICK GENERALIZED OVERVIEW
SECTION 2.0
for what is the STC-2002 used ? . (result) . [the problem, the solution]
. deposit material on a target surface with a controlled and repeatable process .
The STC-2002 addresses the needs of thin film deposition within the vacuum coating industry.
The main function of the STC-2002 is to provide the means for a controlled and repeatable process, which
is the deposition of material on a target surface. [process in which material is deposited on a target surface]
[process that deposits material on a target surface]
(PVD)
< < ii, 2-1 >>
this product is the basis of a controlled and repeatable process .
Without such control, the power [supplies] used to start (or stop) the generation of deposits could be
switched on (or off) at human reaction speeds. Once on, the power [supply] outputs could be altered to vary
the deposit rate, again at human reaction speeds. From the human perspective, the relatively brief time
intervals typically required would be unwieldy at best for accurate control of even a slow process. This
kind of direct human control also assumes that a time versus deposition rate and final thickness is known
for the various deposited materials. Factor in the many physical elements that effect deposition and the
system user, with only time based control, would find it extremely difficult at best for even slowly
accumulating thick depositions, and, for thin depositions, impossible to obtain the desired results, much
less the consistent desired results. The first need is to at least monitor the deposition and know the
thickness (and rate) at any point in time. The next is to be able to control the process based on the
monitored information in real time such that the reaction time between monitor and control is at the needed
speeds. Fortunately, the needed monitor/calculation/control speed is easily within the range of a
moderately priced microprocessor.
The STC-2002 has a microprocessor: on each sensor card, on the user interface board (includes
interconnected displays, keys, touchscreens, etc.) and on the communications/control/database board. This
multiprocessor approach provides greater bandwidth and dedication to specialized functions with obvious
benefits: speed, control, etc. The microprocessors used are actually microcontrollers, which can include
A/D, D/A, communications, etc. thus providing cost savings and greater reliability because of the higher
degree of integration. .
[in speed and control] .
. [Along with an oscillator and crystal sensor(s), the STC-2002 instrument is the basis of a controlled and
repeatable material deposition process system. ] .
Along with an oscillator and crystal sensor(s), the STC-2002 instrument is the basis of process control and
repeatability within a material deposition system.
[of a material deposition system] The STC-2002 can be
used to monitor and control the process manually, or to monitor and control the process automatically.
Utilizing the inherent flexibility of the STC-2002, there are many possible levels of manual control
(requiring human intervention at user determined points in the process). This is also true of the automatic
process mode. During an automated process, for example, an input state or some other condition can be
made to pause the process for user inspection. If satisfactory, the automated process can be resumed by
another preprogrammed user input. In addition, reactions between monitor and control (response time,
overshoot control, etching vs. depositing, etc.) can be tailored to meet various requirements by user
programmable parameters (discussed in PID control section).
The material deposited on the target may be from a single element or a compound (alloy) to create single or
multilayered metal deposits, lens coatings, the creation of an alloy combination that has special properties,
metalized plastic, etc. The products range from sunglasses, jewelry, automotive decoration, CDs at the low
end to optical lenses, mirrors, filters, semiconductors, superconductors, metallurgical research, etc. at the
high end.