Pressure Sensor Stacking with Incompressible Fluid
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Solution Overview
Problem
Conventional pressure sensor systems face reliability issues and high production costs due to exposure to aggressive media and bubble/foam formation in gel-filled sensors, and existing oil-filled sensors are expensive to produce while being sensitive to temperature changes.
Innovation Solution
A pressure sensor system using a ceramic substrate with a signal processing element and sensor element housed in a metal sensor housing filled with an incompressible fluid, which provides media protection and allows for temperature compensation, enabling robustness and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If gel is used as insulating medium for media protection, then protection against corrosive media is improved, but bubble/foam formation occurs at pressures above 5 bar and corrosive attack on metallic compounds continues
Solution Approach 1:
The patent changes the physical state parameter of the insulating medium from gel to oil, which eliminates bubble formation at high pressures while maintaining media protection capabilities. The oil filling serves as an incompressible medium that prevents both foam formation and corrosive attack on sensor components.
2Object-affected harmful factors
If steel membranes with plastic or metal housing are used for media insulation, then resistance to aggressive media is improved, but production cost increases significantly
Solution Approach 1:
The patent employs a thin film membrane made of corrosion-resistant material that provides adequate media protection without requiring thick steel membranes. This thin film approach, combined with oil filling, achieves media resistance at lower production cost compared to conventional steel membrane solutions.
3Temperature
If ceramic substrate is used for thermal decoupling, then temperature compensation is improved, but manufacturing complexity increases
Solution Approach 1:
The ceramic substrate performs multiple functions simultaneously: it provides thermal decoupling for temperature compensation, serves as a mechanical support structure for the sensor elements, and acts as a barrier layer. This multi-functionality reduces the need for additional components despite the stacking complexity.
4Measurement precision
If sensor elements are exposed to aggressive media for direct measurement, then measurement capability is maintained, but reliability and functionality deteriorate over long term
Solution Approach 1:
The patent introduces an oil filling as an intermediary medium between the aggressive external environment and the sensor elements. This oil layer transmits pressure forces to the sensor while simultaneously protecting the sensor components from direct contact with corrosive media, thereby maintaining both measurement capability and long-term reliability.
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 system effectively protects against aggressive media, allows for simple temperature compensation, and maintains sensor integrity across varying pressures without significant impairment, while being cost-effective and resistant to temperature changes.
Implementation Method 1
surrounded by an incompressible oil in order to communicate the pressure force
Implementation Method 2
Through the ceramic substrate, the signal processing element and/or the sensor element can be thermally decoupled from the sensor housing
Implementation Method 3
a deformable pressure-sensitive membrane that is typically exposed to the surrounding media
Data Source
AI summary
A pressure sensor system having at least one pressure sensor device. The pressure sensor device has a stack having a ceramic substrate, at least one signal processing element, and at least one sensor element. The pressure sensor device is placed in a sensor housing provided with a membrane, and a residual volume of the sensor housing provided with the membrane is filled with an incompressible fluid. A method for producing such a pressure sensor system, and to a measuring device, are also described.