INFICON SQM-242 Thin Film Deposition Controller Card Software Operating Manual - Manual (Page 84)

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SQS-242 Operating Manual
6 Set PID Values: In the Edit Process, Deposition tab set P=25, I= TIMESR, D=0.
Assure that all Conditioning values are set to zero. Save the values and close
the Edit Process dialog. Press Start Process and observe the Power graph. The
power should rise from 0%, and stabilize near PWRDR with little ringing or
overshoot. If there is more than about 10% overshoot, lower the P Term. If the
time to reach PWRDR is very slow, increase the P Term. A lower I Term will
increase response time, a higher value will eliminate ringing and setpoint
deviations. It is unlikely you will need any D Term.
Continue to Start the process and adjust PID until steady-state response is
smooth and the step response is reasonably controlled. You don't need to
totally eliminate ringing during the step if the steady-state response is smooth.
Preconditioning will minimize step changes.
7 Set Preconditioning: The power level you recorded as PWR0R is the power
where deposition just begins. That's a good value for Ramp 1 power. PWRDR,
or slightly less, is a good value for Ramp 2 Power. This will eliminate a large
step change when entering the deposition phase.
Once PID terms are established for a material, they will typically be similar for other
materials. Only the P Term and preconditioning power levels may need adjustment.