MEMS Taper Layer Clamping for Thin Membrane Robustness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MEMS structures with membrane structures face challenges in achieving a balance between stability and performance, particularly in applications requiring robustness under high pressure conditions, such as True Wireless Stereo (TWS), where mechanical strain can lead to failure.
Innovation Solution
A MEMS structure design featuring a second clamping structure with a structured taper layer and a second structured oxide layer that extends laterally over the cavity, providing improved support to the membrane structure, while a first clamping structure is laterally offset to form a gap, reducing stress hotspots and enhancing mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the membrane structure size or thickness is increased to improve stability, then the mechanical robustness is improved, but the device performance is negatively affected
Solution Approach 1:
The patent applies local quality by implementing a structured taper layer with varying thickness (from thicker region to thinner region) at specific locations where mechanical support is needed, rather than uniformly increasing the entire membrane structure. This allows localized strengthening at the clamping structure interface while preserving the performance characteristics of the main membrane area.
Solution Approach 2:
The patent uses composite materials by combining the membrane structure with a structured oxide layer and a structured taper layer (e.g., SiON or SiO2) to create a composite clamping structure. This composite approach provides enhanced mechanical support and stress distribution without requiring the entire membrane to be thicker, thus maintaining performance while improving robustness.
2Ease of manufacture
If a single back-plate design is used to simplify structure, then manufacturing is easier, but the Distance Airblow Test robustness is insufficient
Solution Approach 1:
The patent segments the clamping structure into multiple functional layers: a first clamping structure with a first structured oxide layer, a second clamping structure with a second structured oxide layer and structured taper layer. This segmentation allows each layer to perform specific functions (support, stress distribution, gradual transition) that collectively achieve high DAT robustness while maintaining manufacturing feasibility through standardized deposition processes.
Solution Approach 2:
The patent adds dimensional complexity by introducing a structured taper layer with gradual thickness variation in the vertical dimension, transitioning from the second structured oxide layer to the membrane structure. This dimensional approach (varying thickness rather than uniform structure) provides superior mechanical support and stress distribution for DAT robustness without significantly complicating the manufacturing process.
3Reliability
If the first clamping structure is positioned close to the cavity to maximize support, then mechanical support is improved, but stress hotspots are created leading to potential failure
Solution Approach 1:
The patent implements beforehand cushioning by introducing a structured taper layer with gradual thickness transition between the second structured oxide layer and the membrane structure. This gradual transition acts as a cushion that distributes mechanical stress evenly, preventing the formation of stress hotspots that would occur with abrupt transitions, thereby eliminating potential failure points before they can develop under pressure.
Data Source
Figure 1
Figure 2a~2d
Figure 3
AI summary
A MEMS structure, comprising a back-plate structure, a support structure having a cavity, a membrane structure between the back-plate structure and the support structure, a first clamping structure having a first structured oxide layer between the support structure and the membrane structure, wherein an inner edge of the first clamping structure is laterally offset from an edge of the cavity, wherein the offset of the first clamping structure forms a gap between the support structure and the membrane structure, and a second clamping structure having a second structured oxide layer and a structured taper layer between the back-plate structure and the membrane structure, wherein the second structured oxide layer is arranged between the back-plate structure and the structured taper layer, and wherein an inner edge of the second structured oxide layer laterally extends over the cavity, and wherein the structured taper layer is arranged between the second structured oxide layer and the membrane structure and has a tapered edge region, which laterally extends beyond the edge of the second structured oxide layer on the membrane structure.