Silicon microphone

Abstract

The invention provides a silicon microphone, which comprises a shell, and is characterized in that the shell is provided with a sound inlet hole; the base plate and the shell form a accommodating cavity, the sound inlet hole is communicated with the accommodating cavity, one surface of the base plate is provided with a concave cavity, and the concave cavity is provided with an opening; acoustic assembly, the piston is positioned in the accommodating cavity; the acoustic assembly is arranged in the cavity and arranged on the surface of the substrate, the acoustic assembly comprises an MEMS sensor, the MEMS sensor covers the opening, the cavity serves as an extended rear chamber of the MEMS sensor, and the area between the sound inlet hole and the MEMS sensor serves as a front chamber of theMEMS sensor. The silicon microphone has the advantages that the concave cavity is formed in the substrate, the volume of the rear chamber of the MEMS sensor is enlarged, that is, the air volume of the rear chamber is increased, and sound waves entering from the sound inlet hole more easily push the vibrating diaphragm of the MEMS sensor to move, so that the sensitivity and the signal-to-noise ratio of the silicon microphone are improved, Meanwhile, the frequency response performance of the silicon microphone can also be improved.

Description

technical field [0001] The invention relates to the field of micro-electromechanical (MEMS) technology, in particular to a silicon microphone. Background technique [0002] MEMS (Micro-Electro-Mechanical System, Micro-Electro-Mechanical System) technology is a high-tech that has developed rapidly in recent years. It uses advanced semiconductor manufacturing technology to realize batch manufacturing of sensors, drivers and other devices. Compared with the corresponding traditional devices , MEMS devices have very obvious advantages in terms of volume, power consumption, weight and price. In the market, the main application examples of MEMS devices include pressure sensors, accelerometers and silicon microphones. [0003] Silicon microphones, also known as MEMS microphones, are microphones based on MEMS technology. A MEMS microphone is composed of a MEMS sensor, an ASIC amplifier, an acoustic cavity, and a circuit board with an RF suppression circuit. The MEMS sensor chip i...

AI Technical Summary

Problems solved by technology

The air volume in the back chamber of the existing silicon microphone is small, and it is more difficult to push the movement of the silicon diaphragm, resulting in a decrease in the sensitivity of the MEMS sensor, which in turn leads to a decrease in the signal-to-noise ratio of the silicon microphone, and the air volume in the front chamber is large, and the resonance frequency will decrease. , affecting the frequency response performance of silicon microphones

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