Some Design And Simulation On Infrared Detector

There are two steps to infrared imaging: First, the thermal radiation of the scene must be focused onto a sensor to cause a physical effect, such as photoconductivity, which generally requires cooled devices, or a change in a physical property caused by an increase in temperature, as in bolometric devices. Second, the resulting physical effect must be read and displayed. Along with the progress of technology, the sensitivity, temperature range of operation and detection efficiency is update to a higher level increasingly. In future, the infrared detector will develop along the direction of large-scale focal plane array. This paper presents design and simulation of infrared detector.1. The indium bump model has been utilized to investigate the reliability of flip chip joints between infrared detector and readout circuit.. ANSYS finite element models have been developed to analyze the effect of detector size, detector thickness, indium bump height on indium bump reliability. The result shows reliability are significantly influenced by detector size, detector thickness and indium bump height.2. We simulated the heat insulation between quantum-well infrared photodetector and readout circuit.3. This paper presents a PSPICE model for quantum-well infrared photodetectors (QWIP). Bias dependence of the dark current and photocurrent is accurately described by the model with the aid of analogue behaviour modelling technique in PSPICE. The model can be easily integrated with the readout electronics for circuit optimisation.4. Uncooled bi-material infrared detectors have the potential of approaching the theoretical limit of noise equivalent difference in temperature because of its high sensitivity and low noise. Bi-material cantilever beam is simulated by ANSYS. The relation curves of beam thickness ratio vs temperature sensitivity and plate displacement vs capacitance change are presented.