2 loop tuning procedure, Section – INFICON IQM-233 Thin Film Deposition Controller PCI-Express Card Operating Manual User Manual
Page 93
6 - 7
PN
07
4-
58
4-
P1
A
IQM-233 Operating Manual
6.5.2 Loop Tuning Procedure
NOTE: Control loop tuning is a trial and error process and there is no "best"
procedure to accomplish this task. It may take several adjustments to
achieve the desired tune.
1
Set System Parameters
In the Setup window (Setup >> General):
Set Measurement Period to 0.25.
Set Filter Readings to 1 (no filter) to see the noise of the system.
Clear the Enable Simulate check box (if selected).
2
Create a One-Layer Test Process
In the Sensor Setup window (Setup >> Sensor), enter the Z-Ratio and
density of the material being deposited.
In the Source Setup window (Setup >> Source), set the desired rate and a
non-zero Final Thickness (Final Thickness setting must be large enough so
it will not be reached during this procedure).
3
Activate Data Logging
Select the Data Log path by clicking Setup >> Log and choosing the
desired save location.
Click Logging Off (shown in red) on the IQM-233 Standard window.
Logging On will now be displayed in green.
NOTE: Data logging does not collect data until Start is clicked.
4
Test the System Setup
Set Source Control to Manual and click Start.
Slowly increase Power to 10% and verify that the power supply output is
10% of Full Scale. If the readings do not agree, verify that the Full Scale
voltage in the Source Setup window (Setup >> Source) agrees with the
power supply input specifications.
Continue to increase power until the desired rate is achieved.
Log the data for a few minutes.
Slowly decrease power to 0%, and then press Stop.
Plot the data in a spreadsheet program. If the system has significant short
term noise at a fixed power, the control loop will be difficult to adjust,
especially at low rates. The source of the noise should be eliminated before
attempting to set the PID values (see
section 5.1, Troubleshooting Guide,
).