SAW压力传感器声传播方向特性研究  

Research on acoustic propagation direction characteristics of SAW pressure sensor

作　　者：李旺旺 薛卫彪 屈珉敏 LI Wangwang;XUE Weibiao;QU Minmin(Department of Physics,Taiyuan Normal University,Jinzhong 030600,China)

机构地区：[1]太原师范学院物理系,山西晋中030600

出　　处：《传感器与微系统》2023年第11期27-30,共4页Transducer and Microsystem Technologies

基　　金：山西省基础研究计划青年项目(202203021212191);山西省高等学校科技创新项目(2021L413)。

摘　　要：针对高温恶劣环境下对压力参数的测量需求,结合目前氮化铝(AlN)和蓝宝石(sapphire)等耐高温材料,构建了一种叉指换能器(IDT)/AlN/Sapphire结构的声表面波(SAW)传感器模型,并采用有限元法(FEM)分析SAW在c轴取向AlN薄膜上分别沿a方向(〈11-20〉)和m方向(〈1-100〉)传播时的器件性能,包括AlN和IDT的厚度对声速和机电耦合系数的影响,以及不同方向传播时SAW压力传感器灵敏度的变化。实验结果表明:表面波沿a方向传播的传感器相比于m方向明显具有更高的声速与机电耦合系数,2个方向的传感器灵敏度分别为435.37×10^(-6)/MPa和426.29×10^(-6)/MPa,a方向灵敏度略大于m方向。此研究工作为之后的传感器设计制造提供了一定的参考价值。Aiming at the measurement needs of pressure parameters in high-temperature and harsh environments,combined with the current high-temperature-resistant materials such as aluminum nitride(AlN)and Sapphire,a surface acoustic wave(SAW)transducer model with an IDT/AlN/Sapphire structure is constructed,and finite element method(FEM)is used to analyze the device performance of the SAW propagating in a-direction(〈11-20〉)and m-direction(〈1-100〉)on the c-axis oriented AlN thin film,respectively,including the effects of the thicknesses of AlN and IDT on the acoustic velocity and the electromechanical coupling coefficient,as well as the changes of the sensitivity of the SAW pressure sensor when propagating in different directions.The experimental results show that the sensor with surface waves propagating along the a-direction obviously has higher acoustic velocity and electromechanical coupling coefficient compared with the m-direction,but the sensitivity of the sensor in the two directions are 435.37×10^(-6)/MPa and 426.29×10^(-6)/MPa,respectively,and the sensitivity in the a-direction is slightly larger than that in the m-direction.And the work of this research provides certain reference value for the subsequent design and fabrication of sensors in the future.

关 键 词：声表面波压力传感器 有限元法 声传播方向 声速 机电耦合系数 压力灵敏度 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TN384[自动化与计算机技术—控制科学与工程]