Control system for environmental chamber of semiconductor lithography machine utilized in semiconductor industry, has heat exchanger connected to controller, where actual measured variable is produced to control exchanger

摘要

The system has a temperature measuring device measuring temperature difference of medium streams (M1, M2) e.g. air. A heat exchanger (3) is connected to a controller (5) that obtains a measured variable representing actual temperature difference of the medium streams and a reference value (6) as an input signal. Thermoelectric voltage (Ut) is generated in presence of the temperature difference of medium streams, where the temperature difference is determined from the voltage, and an actual measured variable is produced to control the heat exchanger.