Preparation method of MEMS piezoelectric sound pressure sensing chip based on elastic beam structures

Abstract

The invention is suitable for the technical field of hydrophones, and provides a preparation method of an MEMS piezoelectric sound pressure sensing chip based on elastic beam structures. The method comprises the steps of preparing a plurality of elastic beam structures on a first surface of a first silicon wafer through etching to obtain a first sample; preparing a chamber on a first surface of asecond silicon wafer through etching, and preparing a stop structure in the chamber to obtain a second sample; aligning a first surface of the first sample with a first surface of the second sample, and vacuumizing the chamber into a vacuum chamber for bonding; preparing an induction structure on the upper surface of a bonded third sample to obtain the MEMS piezoelectric sound pressure sensing chip based on the elastic beam structures, so that the sensitivity and consistency of the MEMS piezoelectric sound pressure sensing chip are improved, and the acceleration sensitivity of the MEMS piezoelectric sound pressure sensing chip is improved. Meanwhile, the size of the MEMS piezoelectric sound pressure sensing chip is reduced, and the cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of hydrophones, in particular to a method for preparing a MEMS piezoelectric sound pressure sensing chip based on an elastic beam structure. Background technique [0002] A hydrophone is a device based on the principle of hydroacoustics that can measure the sound field in a fluid. The hydrophone can be a device packaged with a MEMS sound pressure sensing chip. Sound waves propagate in water in the form of longitudinal waves, and sound pressure is generated during the propagation process. When the hydrophone outputs the induced voltage signal, when the sound wave propagates to the MEMS miniature hydrophone, the sound pressure first interacts with the packaging structure of the hydrophone. Function, because the packaging structure of the hydrophone is a sound-transparent design, the sound pressure can pass through almost without loss, and the sound pressure through the packaging structure acts on the MEMS sou...

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Problems solved by technology

[0003] In view of this, the embodiment of the present invention provides a method for preparing a MEMS piezoelectric sound pressure sensor chip based on an elastic beam structure, aiming to solve the problem of poor performance of the MEMS sound pressure sensor chip in the prior art and the processing technology Complex, large-chip problems

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