SMALL-SIZED CAPACITOR MICRO-PHONE

摘要

A small-sized capacitor microphone improving reliability is provided to reduce an additional device cost and to omit an additional process for connection of devices by integrating an external RF(Radio Frequency) filter circuit and an amplification circuit on single wafer. A small-sized capacitor microphone(100) includes a sound part and a circuit part. The sound part has a structure where a vibrating film(170) and a back plate(190) are faced in between spacers. The circuit part amplifies a signal received from the sound part, and includes a ECM(Electret Condenser Microphone) chip(110) and a RF filter(120). The ECM chip includes an amplification circuit for amplifying a voltage generated by a variation of capacitance at the sound part. The RF filter prevents a high frequency external noise signal accompanied in an amplification process, and is mounted on a printed circuit board with the ECM chip to one package type.