Sigma SQC-122c manual Chapter Operation

Chapter 2 Operation

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.

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.

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