High-sensitivity MEMS piezoelectric microphone

Abstract

A high-sensitivity MEMS piezoelectric microphone comprises a wafer substrate with a cavity and a plurality of cantilever beams with piezoelectric laminated structures, each cantilever beam comprises afixed end and a free end suspended above the cavity, each cantilever beam is of a structure with a narrow end and a wide end, and the narrower end of each cantilever beam is a fixed end; a fixed column is arranged in the center of the bottom surface of the cavity; the fixed ends of the multiple cantilever beams are connected to the top face of the fixed column, gaps are formed between the adjacent cantilever beams, the free ends of the adjacent cantilever beams are connected with flexible elastic pieces capable of enabling the cantilever beams to vibrate synchronously, and a connecting section used for leading out electric signals of the cantilever beams is arranged in one gap. By changing the structural form of the cantilever beams in the MEMS piezoelectric microphone, the sensitivity and the signal-to-noise ratio of the microphone are improved.

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 ...

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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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