MEMS microphone

Abstract

The invention provides a MEMS microphone. The MEMS microphone comprises a substrate with a vocal cavity, back polar plates fixed on the substrate and vibration films which are arranged oppositely to the back polar plate alternately to form capacitive structures, wherein the back polar plate comprises a back plate and a fixed electrode; the vibration film comprises an effective vibration part and an invalid vibration part; the effective vibration part comprises a vibration body arranged oppositely to the vocal cavity and a fixed arm that is extended by the vibration body and fixed on the substrate; the parts of the vibration body and the fixed arm which are opposite to the vocal cavity form an effective vibration area; the invalid vibration part is located between two adjacent fixed arms and is arranged at intervals with the effective vibration part; the invalid vibration part is at least partially fixed on the substrate; the fixed electrode is the same as the shape of the effective vibration area. Compared with the related technology, the MEMS microphone provided by the invention has better acoustic performance.

Description

technical field [0001] The invention relates to the field of acoustic electricity, in particular to a MEMS microphone used in portable electronic products. Background technique [0002] With the development of communication technology, there are more and more mobile phone users around the world. Users' demand for mobile phones is not only satisfied with calls, but also to be able to provide high-quality call effects, especially the current development of mobile multimedia technology. The call quality of the phone is more important, and the microphone of the mobile phone is used as the voice pickup device of the mobile phone, and its design directly affects the call quality. [0003] Microphones in the related art, particularly MEMS microphones, include a base with an acoustic cavity, a back plate fixed to the base, a fixed electrode fixed to the north plate, and fixed to the base and spaced apart from the back plate to The diaphragm that forms the capacitive structure. The...

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Problems solved by technology

[0004] However, in the MEMS microphone of the related art, the area of ​​the fixed electrode is smaller than the effective vibration area of ​​the diaphragm, so that the effective capacitance of the MEMS microphone is relatively small, resulting in its low performance.

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