MEMS Microphone Comb Tooth Airflow Channel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MEMS microphones face issues with fracture and failure during assembly due to air gun cleaning, as existing pressure relief structures reduce the effective area of the vibrating diaphragm and affect low-frequency characteristics, with limited pressure relief capacity and poor dynamic stability.
Innovation Solution
The MEMS microphone incorporates a vibrating diaphragm with comb tooth parts distributed along its edge, forming an airflow circulation channel between the diaphragm and substrate, which allows for rapid pressure relief and adjustment under overload conditions, enhancing impact resistance and shielding against dust and particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressure relief hole or pressure relief valve structure is provided in the vibrating diaphragm, then the pressure relief capacity is improved, but the effective area of the vibrating diaphragm is reduced and low frequency characteristics are affected
Solution Approach 1:
The patent divides the pressure relief function into multiple segments by providing a plurality of comb tooth parts distributed around the peripheral direction of the vibrating diaphragm. Each comb tooth part acts as an independent pressure relief unit, collectively providing sufficient pressure relief capacity without requiring a large single opening that would compromise the diaphragm's effective area.
Solution Approach 2:
The patent introduces an intermediary structure (comb tooth parts with clearance) between the vibrating diaphragm and the external environment. This intermediary structure provides a controlled pressure relief path through the clearance between comb teeth and the housing, allowing pressure relief without direct large openings in the diaphragm itself, thus preserving the diaphragm's effective area.
2Reliability
If a pressure relief hole or pressure relief valve structure is provided in the vibrating diaphragm, then the pressure relief capacity is improved, but the dynamic stability of the vibrating diaphragm deteriorates
Solution Approach 1:
By segmenting the pressure relief function into multiple distributed comb tooth parts, the structural integrity of the diaphragm is maintained while still providing adequate pressure relief capacity. The segmented approach avoids large single openings that would compromise dynamic stability.
Solution Approach 2:
The comb tooth parts are designed to be movable relative to the housing, allowing the clearance between comb teeth and housing to dynamically adjust based on pressure conditions. This dynamic structure provides pressure relief when needed while maintaining stability during normal operation.
3Reliability
If the comb tooth parts are distributed in the peripheral direction of the vibrating diaphragm, then the pressure relief capacity is improved, but the device complexity increases
Solution Approach 1:
The patent merges the comb tooth parts with the vibrating diaphragm structure itself, making them an integrated part of the diaphragm assembly. This combining approach provides distributed pressure relief capacity while avoiding the need for separate complex pressure relief mechanisms.
Solution Approach 2:
The comb tooth parts serve multiple functions: they provide structural support to the diaphragm, create the pressure relief clearance channels, and distribute the pressure relief function around the periphery. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
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
The airflow circulation channel effectively balances internal and external air pressures, protects the diaphragm from overload pressures, improves low-frequency performance, and prevents damage from dust and particles, while maintaining the microphone's acoustic performance.
Implementation Method 1
an airflow circulation channel... is configured as an airflow circulation channel for airflows to pass by radially to the outside of the MEMS microphone
Implementation Method 2
airflows to pass by radially
Implementation Method 3
a size of the airflow circulation channel can be adjusted according to an overload sound pressure applied in real time, and a pressure relief path is provided for protecting the vibrating diaphragm
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An MEMS microphone is disclosed, which comprises a substrate (1) and a vibrating diaphragm (2) and a back electrode (5) which are located above the substrate (1), a plurality of comb tooth parts (22) are formed in edge positions of the vibrating diaphragm (2), and the plurality of comb tooth parts (22) are distributed in a peripheral direction of the vibrating diaphragm (2) at intervals, wherein a position between every two adjacent comb tooth parts (22) on the vibrating diaphragm (2) is connected to the substrate (1) via an insulating layer; and the comb tooth parts (22) on the vibrating diaphragm (2) are at least partially overlapped with the substrate (1), and a clearance exists between the comb tooth parts and the substrate and is configured as an airflow circulation channel (6). The microphone of the present invention has better impact resistance and can avoid intrusion of dust.