MEMS Microphone Diaphragm Baffle Segmentation for Strength
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Solution Overview
Problem
MEMS microphones face challenges in achieving a balance between high sensitivity and structural strength, particularly due to the weakness of narrow cantilever beams in the diaphragm during impact experiments.
Innovation Solution
A manufacturing method for a micro-electro-mechanical microphone that involves the use of first and second baffles arranged at both ends of the diaphragm along the vibrating direction, limiting the diaphragm's displacement and preventing it from reaching fracture stress levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If narrow cantilever beams are used in the diaphragm to achieve high sensitivity, then the degree of freedom is improved, but the structural strength deteriorates
Solution Approach 1:
The patent divides the diaphragm structure into multiple segments by introducing first and second baffles that connect to the diaphragm at different locations. This segmentation allows the diaphragm to maintain its flexibility and degree of freedom while the baffles provide additional structural support to prevent fracture, thus resolving the contradiction between high sensitivity (degree of freedom) and structural strength.
2Reliability
If the diaphragm is designed with high sensitivity, then the sensitivity parameter is improved, but the reliability deteriorates due to fracture risk
Solution Approach 1:
The patent implements beforehand cushioning by designing the baffle structure that connects to the diaphragm perimeter. This baffle structure acts as a protective element that prevents the diaphragm from undergoing excessive displacement that would lead to fracture stress, thereby cushioning against potential failure while maintaining the diaphragm's high sensitivity characteristics.
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 method enhances the structural strength of the diaphragm while maintaining a high degree of freedom, thereby improving the microphone's sensitivity and reliability.
Implementation Method 1
depositing a first oxide layer on a first surface of the substrate; depositing a first silicon nitride layer on a surface of the first oxide layer
Implementation Method 2
patterning the first oxide layer, the first oxide layer including first connecting through-holes; patterning the second oxide layer, the second oxide layer including a second connecting through-hole
Data Source
AI summary
Provided is a manufacturing method for a micro-electro-mechanical microphone, including: providing a substrate, and forming a first baffle on the substrate; forming a diaphragm at a side of the first baffle, an orthographic projection of a periphery of the diaphragm towards the first baffle falling onto the first baffle; forming a second baffle at a side of the diagram at an interval, the second baffle being connected to the first baffle, and an orthographic projection of the second baffle towards the diaphragm at least partially falling onto a periphery of the diaphragm; forming a back-plate at a side of the second baffle at an interval, the back-plate including acoustic through-holes; and etching the substrate to form a back-cavity. The manufacturing method aims to improve a degree of freedom of the diaphragm to improve sensitivity of the micro-electro-mechanical microphone while improving the structural strength of the diaphragm.