Silicon Microphone Barrier Wall for Diaphragm Jamming
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Solution Overview
Problem
MEMS microphones experience low-frequency attenuation due to the design of diaphragms with 'legs' which inevitably create a narrow gap leading to increased low-frequency noise, and there is a risk of diaphragm jamming or sticking in the back cavity.
Innovation Solution
A silicon microphone design featuring a barrier wall in the first and second vibration spaces between the diaphragm and the base, and between the diaphragm and the backplate, respectively, to increase damping and prevent sticking, with specific height relationships and configurations for the barrier walls to enhance acoustic damping and prevent diaphragm jamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a narrow gap is designed on the diaphragm to form a deflation slot, then the diaphragm can be structurally supported, but low-frequency attenuation increases and noise increases
Solution Approach 1:
A barrier wall is introduced as an intermediary structure between the narrow gap and the back cavity. This barrier wall blocks the direct acoustic path while allowing the narrow gap to maintain its structural support function, thereby reducing low-frequency attenuation and noise without compromising diaphragm stability.
Solution Approach 2:
The back cavity is segmented into a first cavity (closer to the diaphragm) and a second cavity (farther from the diaphragm) by the barrier wall. This segmentation creates acoustic isolation zones that reduce the harmful acoustic coupling through the narrow gap, thereby reducing low-frequency noise while maintaining structural integrity.
2Ease of manufacture
If the diaphragm is designed with legs to provide structural support, then manufacturing is simplified, but the risk of diaphragm jamming or sticking in the back cavity increases
Solution Approach 1:
The barrier wall acts as a physical intermediary that prevents the diaphragm legs from contacting or jamming with structures in the back cavity. This intermediary structure maintains the simple legged design for ease of manufacture while eliminating the reliability issue of diaphragm sticking.
Solution Approach 2:
The barrier wall extends into the back cavity space, creating a new spatial dimension that separates the diaphragm movement zone from the potential jamming zone. This dimensional separation allows the diaphragm to move freely with its legged structure without risking contact with back cavity structures.
3Object-generated harmful factors
If a barrier wall is added to reduce low-frequency attenuation, then acoustic damping improves, but device complexity increases
Solution Approach 1:
The barrier wall is positioned locally at the critical interface between the narrow gap and the back cavity, rather than throughout the entire structure. This localized approach provides maximum acoustic damping benefit while minimizing the addition of structural complexity to the overall device.
Solution Approach 2:
The barrier wall can be implemented as a simple geometric structure that replicates effective acoustic damping patterns without requiring complex manufacturing processes. The structure copies the essential function of acoustic isolation using straightforward geometric forms that are easy to manufacture.
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 barrier wall design effectively reduces low-frequency attenuation and prevents diaphragm jamming or sticking, improving the microphone's performance by increasing damping and maintaining structural integrity during vibrations.
Implementation Method 1
A barrier wall extends along a vibration direction of the diaphragm; wherein the silicon microphone further includes: a first space formed between the narrow gap and the back cavity, and included in a first vibration space which is defined between the diaphragm and the base opposite to the diaphragm; and/or a second space formed between the narrow gap and the through hole of the backplate closest to the narrow gap, and included in a second vibration space which is defined between the diaphragm and the backplate
Data Source
AI summary
The present invention provides a vibration motor including a housing with an accommodation space, a vibration member and a fixed member accommodated in the accommodation space, and an elastic support member suspending the vibration member. The elastic support member has an elastic arm, a first fixed part, and a second fixed part. Both the first fixed part and the second fixed part are bent toward the same side of the elastic arm, and the vibration member is located between the first fixed part and the second fixed part. The elastic stress of the elastic support member is effectively improved and the service life of the elastic support member is improved.