压电传声器的设计与改进  

Design and Improvement of Piezoelectric Microphone

作　　者：郑洁 梁海 朱彪 

机构地区：[1]深圳市豪恩声学股份有限公司,广东深圳518118

出　　处：《压电与声光》2015年第3期453-455,共3页Piezoelectrics & Acoustooptics

基　　金：深圳市战略新兴产业发展专项资金科学基金资助项目(CXZZ20120611094042983)

摘　　要：用多孔压电驻极体薄膜替代传统驻极体电容式传声器(ECM)的声电转换单元,制作出压电传声器。利用压电驻极体超薄的优势和对结构进行改进,将压电传声器的厚度从3mm降低到了1mm。为了解决压电传声器灵敏度低的问题,在后端电路采用了30dB增益的管芯。同时,为了减小寄生电容对灵敏度的影响,采用了单面布铜的印刷线路板(PCB),但将该传声器接入手机使用时会有电磁干扰(EMI)。改进PCB的设计,采用双面布铜的PCB,加强了电磁屏蔽,成功解决了压电传声器的EMI问题。最后,利用压电驻极体薄膜的防水性,并对压电传声器的电路进行了防水保护,使得压电传声器达到了IPX7防水标准。By using the porous piezoelectret film to replace the acoustic-electric conversion of conventional electret condenser microphone （ECM）, a piezoelectric： microphone was fabricated in this work. By making use of the ad vantage of ultra-thin piezoelectret film and the structure improvement, the piezoelectric microphone＇s thickness was reduced from 3 mm to 1 ram. We adopted 30dB gain FET in the microphone＇s circuit to solve the problem of low sensitivity. And in order to reduce the influence of parasitic capacitance, we used the single copper PCB. However, when the microphone connected into mobile phone, it subjected to the electromagnetic interference（EMI）. After that, we improved the PCB design by using double-sided copper PCB to enhance electromagnetic shielding, and resolved the problem of EMI. Finally, by making use of the waterproof performance of piezoelectret film, and by waterproofing the piezoelectric microphone circuit, the piezoelectric microphone satisfies the IPX7 waterproof stand- ards.

关 键 词：压电驻极体 压电传声器 灵敏度 结构设计 寄生电容 电磁干扰 防水 

分 类 号：TN641[电子电信—电路与系统]