Thermal protection system for a chemical vapor deposition machine

A thermal protection system in a chemical vapor deposition machine (CVD) comprising:

• a means for providing a temperature signal representing the temperature of a CVD chamber;
• a means for heating said CVD chamber;
• an interlock means coupled to said heating means, said interlock means having an open state for activating said heating means and a closed state for inactivating said heating means;
• a means for regulating said temperature of said CVD chamber coupled to receive said temperature signal and for regulating said temperature of said CVD chamber by controlling said heating means via said interlock means in response to said temperature signal;
• and
• a means for comparing said temperature signal and a reference voltage, said comparing means coupled to receive said temperature signal, said comparing means controlling said interlock means to said open state when said temperature signal exceeds said reference voltage to override said regulating means if said regulating means fails to prevent an over-temperature condition.

A thermal protection system in a chemical vapor deposition machine (CVD) comprising:

• a thermal sensor operable for providing a temperature signal representing the temperature of a CVD chamber;
• a heating component coupled to said CVD chamber operable for heating said CVD chamber;
• an interlock circuit coupled to said heating component, said interlock circuit having a closed state operable for activating said heating component and an open state operable for inactivating said heating component;
• a controller coupled to said interlock circuit to receive said temperature signal, said controller operable for regulating said temperature of said CVD chamber by controlling said heating component via said interlock circuit in response to said temperature signal, wherein said controller is prevented from regulating said heating component when said interlock circuit is in said open state;
• and
• a comparison circuit coupled to said thermal sensor to receive said temperature signal, said comparison circuit operable for comparing said temperature signal and a reference, said comparison circuit operable for controlling said interlock circuit to said open state when said temperature signal exceeds said reference to override said controller if said controller fails to prevent an over-temperature condition.