MEMS Microphone Absorbing Unit Slits for Thermal Deformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MEMS microphones experience deformation of the vibration membrane due to thermal expansion differences when mounted on a printed circuit board, leading to sensitivity deterioration.
Innovation Solution
Incorporating an absorbing unit with a predetermined pattern of slits along the circumference of the vibration membrane to absorb substrate shrinkage variations, preventing deformation during high-temperature mounting processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the MEMS microphone package is mounted on the PCB by surface mounting process at high temperature, then the manufacturing efficiency and productivity are improved, but the vibration membrane deforms due to thermal expansion differences, deteriorating the sensitivity
Solution Approach 1:
The absorbing unit is divided into multiple slit structures that are separated along the circumference of the vibration membrane. These slits create discrete absorption zones that independently manage thermal expansion stresses, preventing uniform deformation across the membrane while maintaining overall structural integrity during high-temperature mounting
Solution Approach 2:
The absorbing unit is positioned specifically at the circumference of the vibration membrane where thermal expansion stresses are most concentrated. The slit patterns are locally optimized to absorb expansion variations in this critical region, allowing the rest of the membrane to maintain its precise vibrational properties without compromise
2Manufacturing precision
If the absorbing unit is designed with a predetermined pattern of slits, then the vibration membrane deformation is prevented, but the device complexity increases
Solution Approach 1:
The absorbing unit is extracted as a separate functional element from the main vibration membrane structure. The slits are cut into the absorbing unit rather than directly into the membrane, isolating the complex deformation-absorbing function to a dedicated component that can be optimized without compromising the membrane's simplicity and vibrational performance
3Manufacturing precision
If the slits are cut toward the outside of the fixed membrane, then the substrate shrinkage variation is absorbed effectively, but the area of the acoustic component decreases
Solution Approach 1:
The slits extend only over a predetermined section toward the outside of the fixed membrane rather than covering the entire circumference. This partial extension is sufficient to absorb the critical thermal expansion variations at the membrane periphery while preserving the majority of the acoustic component's area for its primary sound transmission function
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 absorbing unit effectively maintains the sensitivity of the microphone module by preventing deformation of the vibration membrane, ensuring consistent performance even after mounting on a printed circuit board.
Implementation Method 1
deformation occurs from the difference between thermal expansion coefficients due to the thickness difference of substrates
Implementation Method 2
When the components that expanded during the bonding process at a high temperature return to the room temperature, deformation occurs
Data Source
AI summary
A microphone apparatus is disclosed. A microphone apparatus according to an exemplary embodiment includes a vibration membrane disposed inside a case and formed on an upper surface of a main substrate; an acoustic component including an absorbing unit cut over a predetermined section toward the outside of a fixed membrane and having a predetermined pattern; a microphone module including a semiconductor chip electrically connected to the acoustic component inside the case; and a printed circuit board on which the microphone module is mounted.