MEMS Pressure Sensor Anchor Segmentation for Parasitic Capacitance Reduction
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Solution Overview
Problem
Existing MEMS pressure sensors face high power consumption due to parasitic capacitance, particularly from the anchor portion of the movable electrode, which affects operational efficiency.
Innovation Solution
The anchor portion of the MEMS pressure sensor is designed with slits and an insulating film embedded within these slits to electrically isolate it from the movable portion, significantly reducing parasitic capacitance and thereby minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the anchor portion is electrically connected to the movable portion, then structural integrity is maintained, but parasitic capacitance increases leading to high power consumption
Solution Approach 1:
The anchor portion is divided into multiple anchor electrodes that are electrically isolated from each other and from the movable electrode. This segmentation eliminates the parasitic capacitance between the anchor portion and movable portion while maintaining structural support, thereby reducing power consumption in the readout circuitry.
Solution Approach 2:
The electrical connection between the anchor portion and movable portion is removed. The anchor portion is extracted as a separate electrical entity with its own electrodes that do not electrically connect to the movable electrode, eliminating the source of parasitic capacitance while preserving mechanical support function.
2Object-generated harmful factors
If the anchor portion is electrically isolated from the movable portion, then parasitic capacitance is reduced, but structural integrity may be compromised
Solution Approach 1:
The anchor portion is segmented into multiple anchor electrodes that can be independently configured to provide both mechanical support and electrical isolation. This segmentation allows the structure to maintain integrity through physical connection while achieving electrical isolation to eliminate parasitic capacitance.
Solution Approach 2:
Insulating layers or dielectric materials are introduced as intermediaries between the anchor electrodes and the movable electrode. These intermediaries provide electrical isolation to reduce parasitic capacitance while allowing the anchor structure to maintain its mechanical support function through the intermediary layer.
3Object-generated harmful factors
If insulating material is added to the anchor portion, then parasitic capacitance is reduced, but manufacturing complexity increases
Solution Approach 1:
The insulating layers are merged with the existing interlayer dielectric structures in the MEMS fabrication process. By integrating the insulation required for electrical isolation into the standard multi-layer dielectric stack already present in MEMS devices, the solution reduces parasitic capacitance without adding significant manufacturing complexity.
Solution Approach 2:
The insulating materials serve multiple functions: they provide electrical isolation to reduce parasitic capacitance, maintain structural integrity as part of the dielectric stack, and facilitate the formation of capacitor structures for pressure sensing. This multi-functionality reduces the need for additional specialized manufacturing steps.
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 design effectively reduces power consumption by minimizing parasitic capacitance, enhancing the operational efficiency of the MEMS pressure sensor while maintaining structural integrity and simplifying the manufacturing process.
Implementation Method 1
an insulating film embedded in slits of the anchor portion can be formed, whereby a part of the anchor portion can be electrically insulated from the movable portion
Implementation Method 2
MEMS pressure sensors comprising diaphragms having MEMS structures as movable electrodes
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
According to one arrangement, a MEMS device includes a first electrode (20) provided on a base substance, and a second electrode (40) including a movable portion (41) and an anchor portion (42) supporting the movable portion (41). The anchor portion (42) is fixed on the substance, and the movable portion (41) is separated from and opposed to the first electrode (20). In addition, a part of the anchor portion (42) is electrically insulated from the movable portion (41).