Rectangular Diaphragm With Corner Depressions for MEMS Sensors
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Solution Overview
Problem
The existing design of MEMS microphones in mobile phones, where the diaphragm is fixed to the basement, results in a reduced sensing area, leading to lower acoustic performance.
Innovation Solution
A diaphragm with depressed parts at its corners and fixed anchor points outside the main body, allowing for increased effective sensing area, and a rectangular diaphragm design with arc corrugated parts, which enhances the acoustic performance by optimizing the diaphragm's fixation and sensing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the entire outer part of the diaphragm is attached to the basement for fixation, then the diaphragm is securely fixed, but the sensing area of the diaphragm is sacrificed, resulting in lower acoustic performance
Solution Approach 1:
The diaphragm is divided into a diaphragm main body and separate fixed parts. The fixed parts are positioned at the corners of the diaphragm main body and include anchor points that extend outward. This segmentation allows the majority of the diaphragm surface to remain free for sensing while only the corner regions are used for fixation, thereby resolving the contradiction between secure fixation and maximum sensing area.
Solution Approach 2:
Different regions of the diaphragm are assigned different functions: the corner regions contain fixed parts with anchor points for fixation, while the central and majority peripheral regions constitute the diaphragm main body with maximum exposed surface area for acoustic sensing. This local differentiation optimizes both fixation stability and sensing area by giving each region its appropriate quality.
2Reliability
If fixed anchor points are placed on the edge of the diaphragm, then the diaphragm can be fixed, but the effective sensing area is reduced
Solution Approach 1:
The fixed parts extend outward from the edge of the diaphragm main body into a separate spatial dimension. The anchor points are positioned outside the boundary of the diaphragm main body, utilizing the corner regions rather than consuming edge perimeter. This dimensional arrangement allows fixation to occur in corner zones without reducing the effective sensing area of the diaphragm main body.
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 solution significantly increases the effective sensing area of the diaphragm, improving the acoustic performance of the MEMS sensor by allowing greater vibration and signal conversion, achieving up to 68% effective sensing area compared to 44-45% in prior art designs.
Implementation Method 1
The diaphragm vibrates under the action of sound waves
Implementation Method 2
the capacity of the capacitive system is changed, thereby converting the acoustic signal into an electric signal
Data Source
AI summary
The present invention provides a diaphragm and a MEMS sensor using the diaphragm. The diaphragm is a rectangular diaphragm, and the diaphragm includes a main body of the diaphragm and fixed parts arranged outside the main body of the diaphragm and located at the four corners of the diaphragm. The four corners of the rectangular diaphragm are depressed parts formed by concave in the direction of the diaphragm main body. The fixed part includes at least two fixed anchor points arranged along the edge of the diaphragm forming the depressed part. The present invention improves the effective sensing area of the diaphragm and the acoustic performance of the MEMS sensor.