基于信噪比的MEMS压力传感器设计与分析  

Design and Analysis of MEMS Pressure Sensor Based on SNR

作　　者：冒晓莉[1] 吴其宇 张加宏[1,2] 李敏[1] 赵雪伟 MAO Xiao-li;WU Qi-yu;ZHANG Jia-hong;LI Min;ZHAO Xue-wei(School of Electronic and Information Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China;Nanjing University of Information Science and Technology,Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,江苏南京210044 [2]南京信息工程大学,江苏省大气环境与装备技术协同创新中心,江苏南京210044

出　　处：《仪表技术与传感器》2022年第2期1-6,20,共7页Instrument Technique and Sensor

基　　金：国家自然科学基金项目(41605120);江苏高校优势学科Ⅲ期建设工程资助项目(PAPD)。

摘　　要：为了研制高精度MEMS压阻式压力传感器,基于信噪比对其压敏结构进行了设计与分析。首先运用ANSYS有限元模拟仿真获得了不同压敏电阻结构芯片的应力分布,并对其噪声和信噪比进行了理论分析,发现在低频区闪烁噪声是传感器噪声的主要来源。仿真结果表明,芯片结构对其噪声、输出信号和信噪比均存在影响,增加压敏电阻折叠条数通常有助于获得更低的噪声和更高的输出信号和信噪比,获得最大输出信号和信噪比最优的电阻长度分别出现在75μm和125μm左右。然后通过MEMS工艺制作部分传感器芯片并封装测试,实测信噪比与理论分析基本吻合。In order to develop a high-precision MEMS piezoresistive pressure sensor,its piezoresistive structure was designed and analyzed based on the signal-to-noise ratio(SNR).Firstly,ANSYS finite element simulation was applied to obtain the stress distributions of the chips with different piezoresistive structures.Then,the noise and SNR were theoretically analyzed.It was found that flicker noise was the main source and concentrated in the low frequency range.The simulation results show that the chip structure has influence on its noise,output signal and SNR.Increasing the number of varistor folds usually contributes to lower noise and higher output signal and signal-to-noise ratios The optimum length of the piezoresistive structures for output signal and SNR appears at about 75μm and 125μm respectively.Then some sensor chips are fabricated by MEMS process and packaged for testing.The measured SNR is basically consistent with the theoretical analysis.

关 键 词：MEMS压阻式压力传感器 噪声 信噪比 传感器结构分析 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]