MEMS红外图像转换芯片是一种将可见光转换为红外辐射并用于红外目标模拟器的直接辐射型器件。对MEMS红外图像转换芯片的热力学性能进行研究: 与标准黑体辐射谱对比表明芯片辐射光谱为黑体谱, 红外波段平均发射率0.638; 通过线扩散函数研究芯片横向热传导特性, 其热扩散距离随衬底厚度降低而减小, 在衬底上制作周期性像元阵列可以有效降低其热传导系数, 衬底厚度360nm的刻有像元的转换芯片热传导系数为0.1W/m·K ; 转换芯片的时间特性研究表明其时间常数随衬底厚度减小而变小, 衬底厚度345nm的芯片制冷至5℃时的时间常数为2.72ms。

The MEMS infrared transducer is a direct radiation device which converts visible light into infrared radiation and can be used in infrared scene simulator. The thermal properties of MEMS infrared transducer are investigated. Compared with the standard blackbody radiation spectrum, the detected results indicate that the transducer is almost a standard blackbody and has an average emissivity of 0.638 in the infrared band. The in-plane thermal conductivity of the transducer is studied by line diffusion function. It is demonstrated that the thermal diffusion distance decreases with the decrease of the thickness of the substrate. Moreover, its thermal conductivity can be effectively reduced by employing periodic pixel arrays on the substrate. The thermal conductivity of the pixel-inscribed transducer with a substrate thickness of 360 nm is 0.1 W/m·K. The transient characteristics of the transducer show that its time constant decreases with the decrease of the substrate thickness, and the value is 2.72 ms with a substrate thickness of 345nm when it is cooled to 5℃.