MEMS Microphone Diaphragm Support via Insulation Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MEMS microphone manufacturing processes are complex and costly due to the need for multiple masks and etching processes, particularly for forming anchors and diaphragm support structures, which increases production time and costs.
Innovation Solution
A MEMS microphone design that eliminates the need for additional anchors by using a first insulation layer to support the diaphragm, reducing the number of masks required and simplifying the manufacturing process, where the diaphragm is supported without a separate anchor, and the back plate is separated from the diaphragm using a chamber and dimple holes, allowing for reduced mask usage and etching steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate masks and etching processes are used to form anchors and diaphragm support structures, then the diaphragm can be supported apart from the substrate, but the number of masks required increases, causing increases in production costs and processing time
Solution Approach 1:
The patent combines the formation of the anchor and diaphragm support structure into a single integrated structure formed by one mask and etching process. The support structure includes both the anchor portion that secures the diaphragm to the substrate and the diaphragm support portion that maintains spacing, all formed simultaneously rather than through separate processes.
Solution Approach 2:
The support structure serves multiple functions: it acts as an anchor to secure the diaphragm, provides mechanical support for the diaphragm, maintains the spacing between diaphragm and back plate, and serves as a structural foundation. This multi-functional design eliminates the need for separate components and processes.
2Manufacturing precision
If multiple masks are used in the manufacturing process to form various components, then precise patterning can be achieved, but the production cost and processing time increase
Solution Approach 1:
The patent merges multiple patterning operations into fewer mask steps. The single mask used to form the support structure simultaneously defines the anchor region, diaphragm support region, and associated features, eliminating the need for multiple sequential masking operations while maintaining precise patterning.
Solution Approach 2:
The support structure is formed in advance as a preliminary feature that subsequently guides and enables other manufacturing steps. By establishing the anchor and support geometry early in the process, subsequent deposition and etching steps can proceed more efficiently without requiring additional masking.
3Ease of manufacture
If separate processes are used to form the anchor and diaphragm support, then each component can be optimized independently, but the manufacturing complexity and time increase
Solution Approach 1:
The anchor and diaphragm support are combined into a single integrated structure formed by one etching process. The continuous support structure maintains both the anchor function and diaphragm support function simultaneously, eliminating the need for separate formation processes while allowing geometric optimization of both functions within the unified structure.
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
This approach simplifies the manufacturing process, reduces production time, and lowers costs by eliminating the need for additional masks and etching steps, while maintaining the ability to convert sound waves into electrical signals effectively.
Implementation Method 1
capacitive MEMS microphones capable of sensing an acoustic pressure to create a displacement corresponding to an acoustic signal
Implementation Method 2
The displacement of the diaphragm can be sensed through a change of capacitance formed between the diaphragm and the back plate
Data Source
AI summary
A MEMS microphone includes a substrate having a cavity, a back plate disposed over the substrate to cover the cavity and having a plurality of acoustic holes, a diaphragm disposed over the substrate to cover the cavity, the diaphragm being disposed under the back plate, including a venting hole communicating with the cavity, and sensing an acoustic pressure to create a displacement, and a first insulation layer interposed between the substrate and the diaphragm to support an end portion of the diaphragm to separate the diaphragm from the substrate, and the first insulation layer having an opening formed at a position corresponding to the cavity to expose the diaphragm. Thus, since the process of forming an anchor may be omitted, the process may be simplified, and process time may be shortened.