MEMS Capacitive Sensor Multi-Substrate Segmentation
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Solution Overview
Problem
Traditional methods for manufacturing micro-electro-mechanical systems (MEMS) that sense and actuate in both in-plane and out-of-plane are costly and inefficient.
Innovation Solution
A method involving the formation of a device structure with a conductive layer, insulating layers, and conductive plugs, where a movable portion is created by etching to form capacitors that vary in capacitance with movement, allowing for both in-plane and out-of-plane sensing and actuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional processes are used to form MEMS that sense and actuate both in-plane and out-of-plane, then the devices can achieve multi-dimensional sensing and actuation, but the manufacturing cost is high and efficiency is low
Solution Approach 1:
The patent divides the manufacturing process into separate stages: forming first capacitive electrodes on a first substrate, forming second capacitive electrodes on a second substrate, and then bonding the substrates together. This segmentation allows parallel processing of different electrode structures, improving manufacturing efficiency while maintaining the capability for both in-plane and out-of-plane sensing and actuation.
Solution Approach 2:
The patent transitions from traditional single-substrate processing to a multi-substrate approach where electrodes are formed on separate substrates before bonding. This dimensional change in the manufacturing process enables more efficient production while preserving the device's multi-dimensional sensing and actuation functionality.
2Adaptability or versatility
If traditional processes are used to form MEMS that sense and actuate both in-plane and out-of-plane, then the devices can achieve multi-dimensional sensing and actuation, but the manufacturing cost is high
Solution Approach 1:
By segmenting the manufacturing process into separate substrate preparations that can be performed independently and in parallel, the patent reduces overall manufacturing complexity and cost while maintaining the sophisticated multi-dimensional sensing and actuation capabilities.
Solution Approach 2:
The patent performs preliminary actions by forming complete electrode structures on separate substrates before bonding them together. This allows for optimized, standardized electrode fabrication processes on each substrate, reducing overall manufacturing cost while enabling complex multi-dimensional device functionality.
3Measurement precision
If capacitive electrodes and circuitry are formed to detect capacitance changes, then sensing capability is achieved, but the device structure becomes complex
Solution Approach 1:
The patent segments the capacitive sensing structures into first and second capacitive electrodes formed on separate substrates. This segmentation simplifies the overall device structure by distributing the complexity across multiple independent components that can be manufactured and tested separately before final assembly.
Solution Approach 2:
By moving to a multi-substrate architecture, the patent redistributes the device complexity across different spatial dimensions and manufacturing stages, making the overall system easier to manufacture while preserving the precise capacitance detection capability needed for sensing.
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 method improves the efficiency and reduces costs associated with producing MEMS devices capable of sensing and actuating in multiple dimensions.
Implementation Method 1
a movable conductive finger over the opening in the insulating layer that forms a first capacitor with the isolated conductive layer that varies in capacitance based on movement of the movable finger
Data Source
AI summary
A device structure is made using a first conductive layer over a first wafer. An isolated conductive region is formed in the first conductive layer surrounded by a first opening in the conductive layer. A second wafer has a first insulating layer and a conductive substrate, wherein the conductive substrate has a first major surface adjacent to the first insulating layer. The insulating layer is attached to the isolated conductive region. The conductive substrate is thinned to form a second conductive layer. A second opening is formed through the second conductive layer and the first insulating layer to the isolated conductive region. The second opening is filled with a conductive plug wherein the conductive plug contacts the isolated conductive region. The second conductive region is etched to form a movable finger over the isolated conductive region. A portion of the insulating layer under the movable finger is removed.