ESC Monitoring Unit(Capacitance Sensor)

HOMEESC Monitoring Unit(Capacitance Sensor)

Connect between the electrostatic chuck (ESC) and the control power supply to monitor the status of the ESC and the workpiece at all times.


ESC Monitoring Unit


  • Detect objects via capacitance change
  • Identify materials by capacitance value
  • Identify topside or bottom side by the difference in capacitance value
  • Monitor ESC status constantly

Key Features

Connection Image


Dimensions W160mm×H85mm×D250mm
*Minor protrusions are excluded
Weight Approx. 900g
Detection Object Silicon wafer, metal foil, various conductor films
Input Voltage DC 24V
Withstand Voltage DC±2.0kV (bipolar ESC)
Power Consumption 2.4W typical
Operating Temperature 0 to 65°C (no condensation)
Digital Output Open collector (NPN non-contact type)
Reference Voltage 2 types
Connector Type Power supply side: MHV
ESC side: MHV


Reference data: Example of loading detection

Capacitive sensors detect changes in the detection electrode (ESC internal electrode) and its vicinity as changes in capacitance. The capacitance of each state obtained by the capacitance detector unit is converted into a voltage signal. By setting the reference voltage and comparing the difference with the detection voltage, it can detect a specific use modes and sudden defects. The following is the result of using a capacitive detection unit to detect each state of the Silicon wafer placed on the ESC.

Equipment Used

Electrical Signal

The capacitance changes in each state are converted into electrical signals as follows:


Download Information

Various materials can be downloaded from here.