A high-sensitivity mems piezoelectric microphone

Abstract

A high-sensitivity MEMS piezoelectric microphone, comprising a wafer substrate with a cavity and a plurality of cantilever beams with a piezoelectric stack structure, the cantilever beams include a fixed end and a free end suspended above the cavity, The cantilever beam is a structure with one end narrow and the other end wide, and the narrower end is a fixed end; the center of the bottom surface of the cavity is provided with a fixed column, and the fixed ends of a plurality of the cantilever beams are connected to the fixed column. On the top surface, there are gaps between the adjacent cantilever beams, and the free ends of the adjacent cantilever beams are connected with flexible elastic parts that can make the cantilever beams vibrate synchronously, and one of the gaps is provided with a The connecting section of the cantilever beam electrical signal. The invention improves the sensitivity and signal-to-noise ratio of the microphone by changing the structural form of the cantilever beam in the MEMS piezoelectric microphone.

Description

technical field [0001] The invention relates to the technical field of microphones, in particular to a high-sensitivity MEMS piezoelectric microphone. Background technique [0002] A microphone is a device that converts sound signals into electrical signals, and is widely used in devices such as microphones, mobile phones, PCs, and vehicle-mounted voice recognition. After long-term development, the current performance indicators of the microphone are more focused on intelligence, digitization and miniaturization. Nowadays, MEMS piezoelectric microphone technology is more and more closely integrated with aerospace, biomedicine, consumer electronics, information communication, and military industries, which puts forward higher requirements for the reliability and sensitivity of the microphone. At present, condenser microphones occupy the main market share, but piezoelectric microphones will be widely used in the field of aeroacoustics in the future due to their advantages of ...

AI Technical Summary

Problems solved by technology

[0003] In the structure of the traditional beam-type piezoelectric microphone, the fixed end of the beam is set on the periphery of the vibration area, and the influence of air damping on the performance of the device is not fully considered in the design, thus reducing the sensitivity and signal-to-noise ratio of the microphone

Patent CN201811650376 discloses a microphone, but the free end of the cantilever beam diaphragm in this disclosed technology fails to effectively maximize the absorption of sound wave energy, and the energy loss is large, resulting in a lack of sensitivity of this type of microphone; patent CN201821645803 discloses a Microphone, this disclosed technology utilizes the cover film connected together by the free ends of the cantilever to keep the synchronous vibration of each cantilever to ensure the stability of the microphone signal output, but the amplitude of the cantilever cannot be maximized, reducing the sensitivity of the microphone

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