MEMS Sound Chip Spring Structure Resonance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MEMS sound producing devices face issues with resonance frequencies falling within the audible band, leading to membrane excursion, Total Harmonic Distortion (THD), Inter-modulation (IM), nonlinearity, and 'colored' sound quality due to high quality factor (Q factor) resonances, which are not effectively addressed by traditional MMC design methodologies.
Innovation Solution
A sound producing chip design with a membrane and actuator configuration where the resonance frequency is moved above the audio band, utilizing a spring structure between the coupling plate and actuator to minimize resonance within the audible range, and a manufacturing method involving a wafer with patterned layers to form a slit-based spring structure, enhancing sound quality by reducing membrane excursion and THD.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional MMC design is applied to MEMS sound producing devices, then the device can generate sound, but resonance frequencies fall within the audible band causing membrane excursion, THD, IM, nonlinearity, and colored sound quality
Solution Approach 1:
The patent changes the physical parameters of the membrane system by introducing a spring structure that modifies the mechanical properties. This alters the resonance frequency parameter, shifting it from the audible band to above 20kHz, thereby eliminating the harmful resonance effects while maintaining sound production capability
Solution Approach 2:
The spring structure acts as an intermediary element between the actuator and the membrane. This intermediate component decouples the direct mechanical connection, allowing independent optimization of the membrane's acoustic properties while controlling the resonance behavior through the spring's mechanical characteristics
2Manufacturing precision
If resonance frequencies are shifted above the audio band using a spring structure, then membrane excursion and THD are reduced, but the device complexity increases
Solution Approach 1:
The spring structure is integrated with the membrane and actuator assembly, merging multiple functions into a unified structure. The spring serves both as a mechanical support element and as a resonance control mechanism, reducing the need for separate components and simplifying the overall device architecture
Solution Approach 2:
The patent utilizes the spring structure as a flexible mechanical element that can be fabricated using thin-film deposition techniques compatible with standard MEMS manufacturing processes. This approach maintains manufacturing simplicity while achieving the desired resonance frequency shift
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 effectively shifts the resonance frequency above the audio band, reducing membrane excursion and THD, thereby enhancing sound quality and reducing resonance-related issues in MEMS sound producing devices.
Implementation Method 1
the resonance frequency is moved above the audio band, utilizing a spring structure between the coupling plate and actuator to minimize resonance within the audible range
Data Source
AI summary
A package structure includes a housing and a sound producing chip. The sound producing chip is disposed within the housing. The sound producing chip includes a membrane and an actuator. The membrane includes a coupling plate and a spring structure connected to the coupling plate. The actuator is configured to receive a driving signal to actuate the membrane. The spring structure is situated between the coupling plate and the actuator. The coupling plate is actuated to move by the actuator via the spring structure.