Suspended MEMS Pressure Sensor Electrode for 7D Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current micromechanical sensor devices face challenges in integrating pressure sensors with inertial and magnetic sensors due to differences in manufacturing processes and evaluation methods, leading to increased complexity and cost, particularly in consumer electronics where miniaturization and functional integration are desired.
Innovation Solution
A micromechanical pressure sensor device with a planar deflectable pressure detection electrode suspended via a plug-like or pin-like joining area, allowing maximal deflection and increased signal sensitivity, enabling 7D or 10D integration with capacitive acceleration, rotation rate, and magnetic field sensors on the same chip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a planar deflectable pressure detection electrode suspended via a plug-like joining area is used, then signal sensitivity increases by over a factor of three, but the device complexity increases due to additional manufacturing steps
Solution Approach 1:
The pressure detection electrode is segmented into a suspended central region and a fixed peripheral region, connected via a plug-like joining area. This segmentation allows the central region to deflect freely under pressure while the peripheral region remains fixed, maximizing signal sensitivity without requiring complete suspension of the entire electrode structure.
Solution Approach 2:
The pressure detection electrode is configured in a planar geometry with suspended regions that deflect in the vertical dimension under pressure. This dimensional approach allows the electrode to maintain a compact planar footprint while achieving large deflection amplitudes in the vertical direction, increasing signal sensitivity without proportionally increasing the planar area.
2Adaptability or versatility
If pressure sensors are produced separately from 6d and 9d modules, then manufacturing processes remain simple and reliable, but the functional integration and space requirements increase
Solution Approach 1:
The MEMS wafer serves as a universal platform that can accommodate multiple sensor types including pressure sensors with suspended electrodes and inertial sensors with capacitive evaluation. Different sensor functionalities are integrated on the same wafer using compatible manufacturing processes, enabling 7D or 10D module production while maintaining process reliability.
Solution Approach 2:
The patent modifies existing MEMS manufacturing parameters and processes to enable the creation of suspended pressure detection electrodes alongside inertial sensors. By adjusting deposition, etching, and release process parameters, the same manufacturing line can produce different sensor types with varying degrees of suspension and deflection characteristics.
3Area of stationary object
If the diaphragm area is reduced to enable greater integration, then space requirements decrease, but the signal sensitivity may be compromised
Solution Approach 1:
The diaphragm structure exhibits local quality variations with a suspended central region that has high deflection capability and a fixed peripheral region that provides structural support. This local differentiation allows the central suspended area to generate strong signals even when the overall diaphragm area is reduced, maintaining signal sensitivity while enabling compact integration.
Solution Approach 2:
The pressure detection electrode and diaphragm structure employ asymmetric design where the suspended central region is optimized for deflection while the peripheral fixed region is optimized for structural integrity. This asymmetric configuration maximizes signal generation in the active area while minimizing the overall diaphragm footprint required for structural support.
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 configuration enhances signal sensitivity by over a factor of three and reduces the diaphragm area, enabling greater integration and cost reduction while maintaining temperature stability and ease of production.
Implementation Method 1
a diaphragm area 26 which is subject to an applied external pressure P and which is elastically deflectable
Implementation Method 2
capacitive evaluation principle in which a diaphragm to which pressure is applied warps and is used as a movable electrode surface
Data Source
AI summary
A micromechanical pressure sensor device includes: an MEMS wafer having a front side and a rear side; a first micromechanical functional layer formed above the front side of the MEMS wafer; and a second micromechanical functional layer formed above the first micromechanical functional layer. A deflectable first pressure detection electrode is formed in one of the first and second micromechanical functional layers. A fixed second pressure detection electrode is formed spaced apart from and opposite the deflectable first pressure detection electrode. An elastically deflectable diaphragm area is formed above the front side of the MEMS wafer. An external pressure is applied to the diaphragm area via an access opening in the MEMS wafer, and the wafer is connected to the deflectable first pressure detection electrode via a plug-like joining area.