MEMS Microphone Spider-Web Counter Electrode Pressure Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing micro-electro-mechanical systems (MEMS) microphones with dual-membrane structures face challenges in optimizing sensitivity and maintaining low noise levels under varying pressures.
Innovation Solution
The MEMS device incorporates a counter electrode with a spider-web-like structure composed of annular beams and spokes, forming through holes and featuring an insulating film and electrode region, which enhances sound pressure sensitivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dual-membrane structure with sealed accommodation space is used, then sensitivity can be optimized, but the sensitivity changes under different pressure conditions
Solution Approach 1:
The counter electrode is segmented into multiple annular beams and spokes, forming a spider-web like structure with multiple through holes. This segmentation allows pressure to be distributed and equalized across multiple points, enabling the accommodation space to maintain stable sensitivity under different pressure conditions while still detecting sound pressure changes.
Solution Approach 2:
The counter electrode is designed with multiple through holes distributed across its structure. These holes function similarly to porous materials by allowing pressure equalization between the accommodation space and the external environment, preventing pressure-induced sensitivity changes while maintaining the sealed space needed for acoustic detection.
2Strength
If a solid counter electrode structure is used, then structural strength is improved, but sound pressure sensitivity decreases
Solution Approach 1:
The counter electrode is divided into multiple annular beams and radial spokes connected together, forming a spider-web like structure. This segmentation maintains structural strength through the distributed framework while creating multiple through holes that enhance sound pressure sensitivity by allowing pressure equalization and reducing acoustic impedance.
Solution Approach 2:
The counter electrode adopts a thin-film spider-web structure with annular beams and spokes that are sufficiently thin and flexible to respond to sound pressure changes. This structure maintains mechanical integrity while being acoustically sensitive, unlike a solid thick electrode would be.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design significantly improves the sensitivity and stability of the microphone, enabling the realization of a low-noise device that maintains performance under different pressure conditions.
Implementation Method 1
the counter electrode is composed of annular beams and first spokes to form a spider-web like structure, which is more sensitive to sound pressure
Implementation Method 2
the counter electrode further includes an insulating film and an electrode region stacked on the insulating film
Data Source
AI summary
An MEMS device, including: a substrate having a back cavity; a diaphragm connected to the substrate and covers the back cavity, the diaphragm includes first and second membranes arranged oppositely, and accommodation space is formed therebetween; a counter electrode in the accommodation space and includes annular beams and first spokes, the annular beams are successively arranged at intervals, and the first spokes extend radially outward from an axis of the counter electrode, an end of the first spokes is connected to the substrate, and two adjacent first spokes and two adjacent annular beams jointly form a first through hole; and a support arranged corresponding to the first through hole, and opposite ends of the support are respectively connected to the first and second membranes. This configuration is more sensitive to sound pressure and is conducive to realizing low-noise microphone while optimizing sensitivity.