电容式微机械超声换能器封装设计

发布时间：2018-06-24 23:01

本文选题：电容式微机械超声换能器(CMUT) + 透声系数　；参考：《压电与声光》2017年04期

【摘要】：针对电容式微机械超声换能器(CMUT)封装材料阻抗匹配失衡,应力大及声波能量损失大等问题,设计了一种在水下10m透声性能好、弯曲形变小的聚氯乙烯封装结构。依据透声理论和材料属性,计算封装结构参数。利用COMSOL Multiphysics 5.0建立封装结构三维有限元模型,通过模态分析和静态分析分别得到封装结构的固有属性和水下机械性能。封装结构的一阶共振频率为792.47Hz,不会对CMUT 400kHz的工作频段产生干扰。利用压力平衡装置保护水下系统安全性,水下10m最大形变为1.12mm,最大应力为14.4 MPa,未超过聚氯乙烯的弯曲强度。实际测试声压与理论值最大误差为4.8%,物距测量误差为1mm,设计的CMUT封装结构满足设计要求。
[Abstract]:Aiming at the imbalanced impedance matching of capacitive micromechanical ultrasonic transducer (CMUT), high stress and large energy loss of acoustic wave, a kind of PVC packaging structure with good sound permeability and low bending deformation was designed. According to the theory of sound transmission and material properties, the package structure parameters are calculated. The 3D finite element model of encapsulated structure is established by COMSOL Multiphysics 5.0. The inherent properties and underwater mechanical properties of encapsulated structure are obtained by modal analysis and static analysis, respectively. The first order resonance frequency of the encapsulated structure is 792.47 Hz, which will not interfere with the CMUT 400kHz operating frequency band. The safety of underwater system is protected by pressure balance device. The maximum deformation of 10 m underwater is 1.12 mm and the maximum stress is 14.4 MPA, which does not exceed the bending strength of PVC. The maximum error between the measured sound pressure and the theoretical value is 4.8 and the error of the distance measurement is 1 mm. The designed CMUT package structure meets the design requirements.
【作者单位】：中北大学仪器科学与动态测试教育部重点实验室;山西古交西山义城煤业有限责任公司;
【基金】：国家自然科学基金资助项目(61127008)
【分类号】：TB552

【参考文献】