Analysis and measurement of thermal-electrical performance of microbolometer detector

Microbolometer detector is very competent as uncooled infrared detector for a wide range of thermal imaging applications, since it has been found to be more sensitive and has the advantage of using standard Si micro-fabrication process compared with pyroelectric or ferroelectric technology. The heart of microbolometer detector is a two dimensional array of thermal sensitive thin-film layers, which can change their temperatures and resistivities depending on the radiation absorbed. During the entire thermal imaging process, the microbolometer detector's substrate temperature, calibration temperature and ambient temperature are the key parameters which determine the thermal-electrical performance and the ultimate imaging quality of the microbolometer detector. In this work, based on the analysis of the characteristics of these parameters, the experiment has been conducted with the uncooled infrared thermal imaging system based on 320×240 amorphous silicon microbolometer detector working at different substrate temperatures, adopting different calibration temperatures for different ambient temperatures. The corresponding measurement results of the system's NETD, residual nonuniformity and power consumption, as well as the system's imaging results are presented, which all have a great agreement of the theory analysis above.