INFICON IC/5 Thin Film Deposition Controller - Manual (Page 85)

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IC/5 Operating Manual
3.6.1.1 CrystalSix Position Select
Used in conjunction with the position-select CrystalSix sensor (IPN 750-446-G1),
the IC/5 allows crystal switching to a predetermined subset of the six crystal
positions, if desired. This subset is selected using the Crystal Position parameter
located on page 3 of the Material Set Up display. (See
section 4.3 on page 4-5 .)
The position select feature allows you to select which of the six crystals are to be
used for a given material. In applications involving sequential layering of different
materials this allows specific crystals to be used for specific materials, eliminating
the need for more than one sensor head in the deposition system.
3.6.1.2 Rotary Sensor Crystal Switching
Selecting type 7, Rotary, as the sensor type enables sequential crystal switching
only. Upon a crystal switch the Crystal Switch Output will first close for one second
and then open (i.e., one pulse to move one position). The IC/5 will not keep track
of which position the Rotary Sensor is on nor will it keep track of which crystals are
good and which are failed. The Position Selection feature available with Type
6=Multi is not available for the rotary sensor.
After the one second pulse, the IC/5 measurement system software will attempt to
find the resonant frequency for the crystal in this position. If the IC/5 does not find
a good resonant frequency for this crystal it will again pulse the Crystal Switch
Output for one second and attempt to find a resonant frequency at this position.
There will be a maximum of five attempts to find a good resonant frequency (i.e., a
maximum of five pulses of the Crystal Switch Output). If a good resonant frequency
is not found after five attempts, the IC/5 will then enter the Time Power or STOP
state depending on the Sensor Option value chosen in the Material parameters
display.
There is to be a maximum of five attempts to find a good resonant frequency
however, while executing a Layer, if the IC/5 detects a crystal fail and automatically
initiates a crystal switch it will recognize there has been an automatic crystal switch.
The IC/5 will keep track of the number of times an automatic crystal switch has
been done. Therefore if there have been five automatic crystal switches and then
the sixth crystal fails, the IC/5 will go directly to either Time Power or STOP as
appropriate without any additional pulses.
Start resets all crystal fail flags to ’good’.