电容式非制冷红外探测器的设计与热力学特性分析

Design and thermodynamic analysis on capacitive uncooled IR detector

本文设计了一种基于MEMS工艺的电容式非制冷红外探测,并利用ANSYS对器件的热力学特性进行了分析。使用ANSYS模拟研究了器件温度响应、位移响应与吸收的红外辐射能量的关系,研究了器件结构尺寸对器件性能参数的影响。红外探测器的温度响应和位移响应与吸收的红外辐射能量呈线性关系;随着红外探测器结构尺寸的增加,其温度响应度、位移响应度、热时间常数都随之增加,探测能力增强,但瞬态响应特性降低;当铝膜与氮化硅层的厚度比为0.5-0.6时,器件的位移响应度最大。

An uncooled MEMS capacitive thermal detector was designed, and its thermal and thermal - structural behaviors were stimulated with ANSYS. The relations between the temperature response and the IR absorption, the displacement response and the IR absorption, and the device performance and the structure dimensions were studied by using ANSYS simulation tools. It is found that both the temperature response and the displacement response increase linearly as the absorbed IR energy increased. With the increasing of the structure dimensions, /he temperature sensitivity, the displacement sensitivity and the thermal time constant increased, but theirs transient performances became worse. The displacement sensitivity of the device reaches a maximum value when the thickness ratio of Al to Si3N4 films was 0.5 -0. 6.