Hybrid Pressure Sensor Diaphragm Electrode Carrier Segmentation
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Solution Overview
Problem
Conventional pressure sensors with pressure-sensitive diaphragms exhibit non-linear capacitance changes due to diaphragm warping, limiting their sensitivity and accuracy, and are sensitive to environmental factors, making them less robust for aggressive environments.
Innovation Solution
A pressure sensor component with a MEMS component featuring a pressure-sensitive diaphragm pattern where the electrode carrier is mechanically coupled to the diaphragm but not deformed by pressure, allowing for linear and sensitive capacitance measurements, and is designed to be robust and resistant to environmental influences by positioning electrodes within a cavity between the MEMS and ASIC components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a closed diaphragm is used in conventional pressure sensors, then the sensor structure is sealed and robust, but the diaphragm warps under pressure causing non-linear capacitance changes and reduced measurement precision
Solution Approach 1:
The diaphragm structure is segmented into a closed diaphragm body and a separate movable electrode carrier. The electrode carrier is mechanically coupled to the diaphragm but remains planar while the diaphragm warps, separating the sealing function from the measurement function to eliminate warping-induced non-linearity.
Solution Approach 2:
The electrode carrier acts as an intermediary element between the diaphragm and the measurement capacitor. It translates the diaphragm's warping motion into a controlled capacitance change while maintaining its own planar shape, thereby mediating between the sealed diaphragm structure and the linear measurement requirement.
2Device complexity
If the electrode is positioned on the closed diaphragm, then the structure is simple, but the electrode deforms with the diaphragm warping reducing measurement accuracy
Solution Approach 1:
The electrode system is segmented into a stationary electrode on the substrate and a movable electrode carrier that remains planar. This separation ensures that the measurement electrode does not deform with the diaphragm, maintaining measurement accuracy while adding minimal structural complexity.
3Measurement precision
If the diaphragm size is increased to improve sensor sensitivity, then the capacitance signal magnitude increases, but the pressure range is limited and the device area increases
Solution Approach 1:
The sensor is segmented into a sealed diaphragm region for pressure sealing and a separate electrode carrier region for measurement. This allows the diaphragm to be optimized for pressure containment while the electrode carrier area can be independently optimized for sensitivity, enabling versatile pressure range adaptation.
Solution Approach 2:
Different regions of the sensor have different functions: the diaphragm region is optimized for sealing and pressure resistance, while the electrode carrier region is optimized for maximizing capacitance signal. This local differentiation allows independent optimization of pressure range and sensitivity.
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
The solution achieves a linear pressure response with high sensitivity, reduces the impact of diaphragm warping on measurements, and enhances the robustness of the pressure sensor for use in aggressive environments by isolating circuit components from environmental influences.
Implementation Method 1
a change in capacitance of the measuring capacitor device
Implementation Method 2
in the case of a pressure effect, the diaphragm electrode is deflected together with the diaphragm
Implementation Method 3
mechanically coupled to the diaphragm element in such a way that a pressure-conditioned deformation of the diaphragm element effects a deflection of the electrode carrier essentially perpendicular to the diaphragm plane
Data Source
AI summary
A pressure sensor component includes a MEMS component having at least one pattern element that is able to be deflected perpendicular to the component plane, which is equipped with at least one electrode of a measuring capacitor device, and an ASIC component having integrated circuit elements and at least one back end stack, at least one counter-electrode of the measuring capacitor device being developed in a metallization plane of the back end stack. The MEMS component is mounted on the back end pile of the ASIC component. The MEMS component includes at least one pressure-sensitive diaphragm pattern and is mounted on the ASIC component in such a way that the pressure-sensitive diaphragm pattern spans a cavity between the MEMS component and the back end stack of the ASIC component.