Piezoelectric mems microphone and its array and preparation method

Abstract

The invention provides a piezoelectric MEMS microphone and its array and preparation method. The piezoelectric MEMS microphone includes a substrate with a back cavity and a piezoelectric diaphragm fixed on the substrate. The piezoelectric diaphragm includes a fixed The diaphragm layer on the base and the piezoelectric layer fixed on the diaphragm layer, the piezoelectric layer is continuously bent to form a wave-shaped structure, and the wave-shaped structure includes the The first surface of the diaphragm layer is recessed toward the diaphragm layer with several first grooves and the second surface of the piezoelectric layer close to the diaphragm layer is recessed away from the diaphragm layer , the first grooves and the second grooves are alternately arranged. Through the above method, the deformation and displacement of the piezoelectric layer under the external sound pressure are increased, thereby increasing the voltage output, effectively improving the sensitivity of the piezoelectric MEMS microphone, and reducing the residual stress of the piezoelectric layer to a certain extent , prolong the service life of the piezoelectric MEMS microphone.

Description

【Technical field】 [0001] The invention relates to the field of acoustic and electric technologies, in particular to a piezoelectric MEMS microphone, an array thereof and a preparation method thereof. 【Background technique】 [0002] MEMS (Micro-Electro-Mechanical System, Micro-Electro-Mechanical System) microphone is a kind of electric energy sound transducer manufactured by micro-machining technology, which has the characteristics of small size, good frequency response characteristics, and low noise. With the development of miniaturization and thinning of electronic devices, MEMS microphones are more and more widely used in these devices. Piezoelectric MEMS microphones have many advantages over traditional capacitive MEMS microphones, including dust and water resistance and higher maximum output sound pressure (AOP). [0003] see figure 1 , for state-of-the-art MEMS microphones, figure 1 The middle base is C, the piezoelectric unit A and the vibrating membrane B are seque...

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Problems solved by technology

[0005] The object of the present invention is to provide a piezoelectric MEMS microphone and its array and preparation method to solve the problem of small deformation caused by flat distributed piezoelectric units in the prior art, resulting in a small output voltage and low sensitivity. defect

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