Thermal forcing system for controlling a temperature of a device under test

A method for controlling a temperature of a device under test, the method comprising:

• a controller receiving information of a temperature sensed by a temperature sensor that is thermally coupled through a thermal plate to the device under test;
• the controller determining a temperature difference between a setpoint temperature and the temperature sensed by the temperature sensor;
• and
• the controller commanding an actuator to move a cold head relative to the thermal plate in response to the temperature difference, so as to facilitate adjusting the temperature of the thermal plate to the setpoint temperature, wherein the cold head has a temperature that is less than a temperature of the thermal plate.

A thermal control unit for controlling a temperature of a device under test, the thermal control unit comprising:

• a cold head including an evaporator for absorbing latent heat;
• a thermal plate thermally coupleable to a device under test;
• and
• an actuator mechanically coupled to the cold head for controllably moving the cold head relative to the thermal plate.