Sensor system and manufacturing process as well as self-testing process

A sensor system for the detection of thermal radiation, with a substrate, several sensor elements, each attached to the substrate and each of which generates an electrical signal representative of the thermal radiation striking it, characterized by a signal-processing device which converts at least the electrical output signals of sensor elements lying parallel to one another into a serial signal and delivers this to an output;

• a calibrating device for permanently setting the characteristic curve of at least one sensor element;
• and
• several self-test devices which are formed differently from one another in such a way that they heat several sensor elements to different levels wherein:
• the signal-processing device is formed either on the substrate or on its own substrate, in the immediate vicinity of the substrates of the sensor elements and is electrically connected to the said sensor elements;
• the sensor system comprises a device for the measurement of temperature, which delivers a signal representative of the absolute temperature.

A method of operating a sensor system utilizing at least one sensor element for the detection of thermal radiation comprising;

• providing at least one self-test device between a slot provided as an insulating device and the sensor element;
• heating that at least one self-test device;
• monitoring the electrical signal from at least one sensor element;
• driving a self-test device with a characteristic electric signal that exhibits two or more pulses and/or a signal which changes over time;
• and
• continuing monitoring the sensor system during the self-testing process, removing an anticipated characteristic signal determined on the basis of the operation of the self-test device, in order to serve as a signal for monitoring.

Process for the production of a sensor system for detecting thermal radiation using sensor elements which deliver an electrical signal representative of the thermal radiation striking each and several self-test devices provided for the generation of heat, each assigned to a respective sensor element on a substrate comprising:

• producing porous silicon using an electrochemical process on a front side of said substrate;
• forming depressions in the porous silicon using surface-micromechanics;
• and
• applying several sensor elements to the substrate disposed over said depressions.