Differential capacitive MEMS (Micro-Electro-Mechanical System) microphone

A differential capacitor and microphone technology, applied in the field of microphones, can solve the problems of high signal-to-noise ratio, inability to filter out interference signals, affecting the noise level of output signals, etc.

Inactive Publication Date: 2015-09-09
GOERTEK INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The problem with the above technical solution is that a single capacitance detection cannot filter out external interference signals, which affects the noise level of the output signal and cannot achieve a high signal-to-noise ratio

Method used

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  • Differential capacitive MEMS (Micro-Electro-Mechanical System) microphone
  • Differential capacitive MEMS (Micro-Electro-Mechanical System) microphone
  • Differential capacitive MEMS (Micro-Electro-Mechanical System) microphone

Examples

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no. 1 example

[0030] The package cavity is surrounded by the circuit board 4 and the shell 5 , and the first MEMS chip 1 , the second MEM chip 2 , and the ASIC chip 3 are arranged inside the package cavity, and the shell 5 is provided with an acoustic hole 51 .

[0031] The first MEMS chip 1 includes: a first base 11 arranged on the circuit board 4, the first base 11 is provided with a first opening 111 which penetrates up and down; The first capacitor, the first capacitor includes the first back plate 14 at the top, the first diaphragm 12 opposite to the first back plate 14 at the bottom, and the first diaphragm 12 arranged between the first back plate 14 and the first diaphragm 12 between the first isolation layer 13 that keeps the gap between the two.

[0032] The second MEMS chip 2 includes: a second base 21 arranged on the circuit board 4, the second base 21 is provided with a second opening 211 penetrating up and down; The second capacitor, the second capacitor includes the second ba...

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Abstract

The invention discloses a differential capacitive MEMS (Micro-Electro-Mechanical System) microphone. The differential capacitive MEMS microphone comprises a circuit board, a first MEMS chip and a second MEMS chip, wherein the first MEMS chip comprises a first substrate arranged on the circuit board, and a first capacitor which is arranged on the first substrate and comprises a first back polar plate positioned above, a first vibration film positioned below and a first isolation layer arranged between the first back polar plate and the first vibration film; the second MEMS chip comprises a second substrate arranged on the circuit board, and a second capacitor which is arranged on the second substrate and comprises a second back polar plate positioned below, a second vibration film positioned above and a second isolation layer arranged between the second back polar plate and the second vibration film; and the first capacitor and the second capacitor construct a pair of differential capacitors. Through adoption of the differential capacitive MEMS microphone disclosed by the invention, external noise signals can be filtered; the signal-to-noise ratio is increased; and the performance of a microphone product is enhanced.

Description

technical field [0001] The utility model relates to a microphone, in particular to a differential capacitive MEMS microphone. Background technique [0002] MEMS microphone is an acoustic-electric transducer manufactured by micromachining technology, which has the characteristics of small size, good frequency response characteristics, and low noise. With the miniaturization and thinning of electronic devices, MEMS microphones are more and more widely used in these devices. [0003] At present, MEMS microphone products include a MEMS chip based on capacitance detection and an ASIC chip. The capacitance of the MEMS chip will change with the input sound signal, and then use the ASIC chip to process and output the changed capacitance signal to achieve Sound pickup. MEMS chips usually include a substrate with a back cavity, and a parallel plate capacitor composed of a back plate and a diaphragm arranged above the substrate. The diaphragm receives external sound signals and vibra...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04R19/04
CPCH04R3/005H04R19/005H04R19/04H04R1/04H04R7/04H04R2201/003H04R2307/025H04R2410/01
Inventor 郑国光
Owner GOERTEK INC
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