Design, Fabrication and Testing of Thermistor Detector

The main idea of this work is to design and fabricate an infra-red detector, specially the disk type of negative thermistor (NTC), and to test it’s operation and response to different levels of IR laser power. The challenge of the fabrication arises from the chemical, physical and electronic thermistor features. In order to get good responsivity, a certain semiconductor oxides ratio prepared and milled with special size and shape under tones of pressure, then sintered with thousand of temperature degrees, and finally coated and attached with legs to get the thermistor. An electronic circuit, consists of some amplifiers, comparator and reference voltage, was used to test the disk thermistor operation. Finally, different levels of Nd:YAG laser power was used to test the fabricated thermistors. The results are very promising and the best ratios of the mixture could be easily determined.