Capacitive Sensor Electrode Recesses for Parasitic Capacitance Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive sensors face a reduction in signal-to-noise ratio (SNR) due to increased parasitic capacitance when the distance between electrodes is reduced to enhance sensitivity, leading to decreased performance in detecting physical quantities like acceleration and position.
Innovation Solution
The capacitive sensor design incorporates a recess between adjacent electrodes, using a dielectric material with a lower dielectric constant than the substrate, and forming gaps between electrodes to reduce parasitic capacitance, thereby increasing the ratio of detection capacitance to parasitic capacitance and enhancing the SNR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the distance between capacitive sensing electrodes is reduced to increase sensitivity, then the sensitivity of capacitive sensors is improved, but the signal to noise ratio deteriorates due to increased parasitic capacitance
Solution Approach 1:
The patent extracts and removes the dielectric material from the regions between adjacent electrodes to form recesses. This extraction eliminates the source of parasitic capacitance (the dielectric material with high dielectric constant) while preserving the electrode structure needed for sensitivity, thereby resolving the contradiction between sensitivity and signal-to-noise ratio
Solution Approach 2:
The patent applies different dielectric properties to different regions: the regions between electrodes have recesses (effectively air or vacuum with low dielectric constant) while the regions under electrodes maintain the original dielectric material. This local differentiation reduces parasitic capacitance in critical areas while preserving detection capacitance, resolving the contradiction between sensitivity and signal-to-noise ratio
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 parasitic capacitance, improving the signal-to-noise ratio and increasing the sensitivity of capacitive sensors, allowing them to detect smaller changes in physical quantities with higher accuracy.
Implementation Method 1
using a dielectric material with a lower dielectric constant than the substrate
Implementation Method 2
reducing parasitic capacitance associated with capacitive sensors
Data Source
AI summary
The present disclosure includes methods of forming capacitive sensors. One method includes forming a first electrode array of the capacitive sensor on a first structure. Forming the first electrode array can include: forming a dielectric material on a substrate material; forming an electrode material on the dielectric material; removing portions of the electrode material to form a number of electrodes separated from each other; and removing at least a portion of the dielectric material from between the number of electrodes. The method can include bonding the first structure to a second structure having a second electrode array of the capacitive sensor formed thereon such that the number of electrodes of the first electrode array face a number of electrodes of the second electrode array.