Single membrane capacitance type microphone chip

Abstract

The present invention discloses a single film capacitance type microphone chip, which relates to a microphone technology, the present invention is a single film capacitance type microphone, a capacitance structure is formed by utilizing a single film and a base seat. A vibrating diaphragm is connected with the upper surface of a cantilever beam support through the cantilever beam frame of the cantilever beam, forming a three-dimensional vibrating structure that the cantilever beam and the vibrating diaphragm is not at the same level; the cantilever beam is flexible, the vibrating diaphragm is rigid, the distortion is mainly concentrated on the cantilever beam when the vibrating diaphragm vibrates, the vibrating diaphragm basically keeps a translational movement; a plurality of apertures are arranged on the edge of the vibrating diaphragm to improve a frequency response property, a corrosion hole is arranged simultaneously; in addition, a shock-proof back stop is manufactured on the chip. The present invention has the advantages that the sensitivity is high, the noise is low, the property is wide frequency band, the volume of the chip is small, the manufacture process is simple, and the volume production is easy.

Description

technical field [0001] The invention relates to the technical field of microphones, in particular to a single-film condenser microphone chip. Background technique [0002] The research on semiconductor microphone chips has a history of more than 20 years, during which various types of microphones have been developed and implemented on silicon chips. Among them, the most important and popular one is the condenser silicon microphone. Capacitive silicon microphones not only have the characteristics of small size, high sensitivity, good frequency response characteristics, and low noise, but more importantly, they have a wide operating temperature and are suitable for SMT and other automated production lines and harsh working environments. [0003] For capacitive silicon microphones, the current reports and patents mostly use a double-film capacitor structure. Micro-machining technology is used to make a diaphragm and a double-film back electrode on a silicon chip to form a capa...

AI Technical Summary

Problems solved by technology

The double-film condenser semiconductor microphone needs to make a double-layer free film on the substrate. The manufacturing process is relatively complicated, and it faces technological problems such as "soft back electrode" and adhesion.

Compared with the double-film condenser semiconductor microphone, the single-film condenser semiconductor microphone has a simple structure and is easy to realize, but the reported single-film semiconductor condenser microphone has deficiencies, which are mainly manifested in: 1. Low sensitivity: the silicon substrate acts as the back electrode Considering the acoustic requirements, a sound hole should be left on the substrate. Due to the limitation of the process, the position of the sound hole must face the middle area of ​​the diaphragm, and the middle area of ​​the diaphragm has high mechanical sensitivity and low edge, which wastes the middle position of the diaphragm. , which reduces the sensitivity of the microphone. Second, the frequency response characteristics are poor: the sound hole is only in the middle of the diaphragm, and the microphone has poor frequency response characteristics when the diaphragm vibrates.

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