公开(公告)号：EP3518558A1

公开(公告)日：2019-07-31

申请号：EP17832031.3

申请日：2017-11-30

Applicant: Goertek Inc.

Inventor： ZOU, Quanbo ,  WANG, Zhe ,  DONG, Yongwei

IPC: H04R19/00 ,  H04R19/04

Abstract: The present invention discloses a MEMS microphone, which comprises a substrate, a first vibrating diaphragm and a second vibrating diaphragm. A sealed cavity is formed between the first vibrating diaphragm and the second vibrating diaphragm. A back electrode unit is located in the sealed cavity, forms a capacitor structure with the first vibrating diaphragm and with the second vibrating diaphragm respectively, and is provided with a plurality of through holes that penetrate through two sides thereof. The sealed cavity is filled with a gas whose viscosity coefficient is smaller than that of air. According to the MEMS microphone disclosed by the present invention, by filling the sealed cavity with a gas whose viscosity coefficient is smaller than that of air, the acoustic resistance when the two vibrating diaphragms move relative to the back electrode can be reduced greatly, thereby reducing the noise of the microphone. Meanwhile, by the use of a gas with a low viscosity coefficient for filling, the pressure in the sealed cavity is consistent with the pressure of an external environment, thereby avoiding the problem of vibrating diaphragm deflection caused by pressure difference and ensuring the performances of the microphone.