Pressure Sensor Assembly With MEMS Stress Decoupling
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Solution Overview
Problem
Existing pressure sensor assemblies are not suitable for high-pressure applications, particularly when using integrated pressure sensors like MEMS chips, due to mechanical coupling complexities and instability under high pressure.
Innovation Solution
A pressure sensor assembly design featuring a housing with a pressure-tight chamber containing a sensor chip surrounded by the medium, using stress relieving structures such as elastic adhesive layers or flexible connection pins to mechanically decouple the housing and sensor chip, eliminating the need for a diaphragm and external coupling media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If integrated pressure sensors (MEMS chips) are used in high-pressure applications, then measurement precision and device simplicity are improved, but mechanical coupling complexity and reliability deteriorate due to the need for complex mechanical coupling structures and oil volume coupling
Solution Approach 1:
The patent extracts and eliminates the steel diaphragm and oil coupling medium from the measurement system. The sensor chip is placed in direct contact with the pressurized medium, removing the need for mechanical coupling structures. This extraction simplifies the device while maintaining high measurement precision, as the sensor directly measures medium pressure without interference from coupling mechanisms.
Solution Approach 2:
The patent introduces a stress-relieving structure as an intermediary between the housing and sensor chip. This structure decouples mechanical stresses from the sensor chip while allowing direct pressure measurement. The intermediary protects the sensitive MEMS chip from high mechanical stresses without requiring complex coupling mechanisms, thus reducing device complexity while maintaining measurement accuracy.
2Reliability
If steel diaphragm is used for high-pressure measurement, then reliability under high pressure is improved, but device complexity and manufacturing cost increase due to complicated mechanical coupling structures
Solution Approach 1:
The patent removes the steel diaphragm from the system entirely. Instead of using a steel diaphragm for high-pressure measurement, the sensor chip is placed in direct contact with the pressurized medium. This extraction eliminates the complex mechanical coupling structures required to attach and seal the steel diaphragm, reducing device complexity while maintaining reliability through direct pressure sensing.
Solution Approach 2:
The patent replaces the mechanical steel diaphragm system with a semiconductor-based MEMS sensor chip. This substitution eliminates the need for mechanical coupling structures, seals, and mounting mechanisms associated with steel diaphragms. The sensor chip provides reliable high-pressure measurement through direct contact with the medium, significantly simplifying the overall device structure.
3Ease of manufacture
If sensor chip is directly exposed to high-pressure medium, then manufacturing cost and device simplicity are improved, but mechanical stress on sensor chip increases potentially affecting reliability
Solution Approach 1:
The patent introduces a stress-relieving structure as an intermediary between the housing and sensor chip. This structure allows the sensor chip to be directly exposed to the pressurized medium for simple manufacturing, while simultaneously protecting the chip from excessive mechanical stresses. The intermediary absorbs and redistributes stresses, maintaining sensor chip reliability without complicating the manufacturing process.
Solution Approach 2:
The patent modifies the mechanical properties of the mounting structure by using elastomeric materials with specific stress-relieving characteristics. This parameter change allows the sensor chip to withstand high-pressure environments while preventing stress concentration that could damage the chip. The elastomeric material provides both direct pressure transmission for manufacturing simplicity and stress distribution for 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
Enables reliable high-pressure measurements with integrated sensor chips by preventing mechanical stress transfer, ensuring accurate and stable pressure readings without additional mechanical components.
Implementation Method 1
the stress relieving structures comprising an elastic adhesive layer which connects the sensor chip to the housing part
Data Source
AI summary
In the following, a sensor assembly is described. According to an exemplary embodiment, the sensor assembly has a housing enclosing a pressure chamber filled with a medium, the housing having a first housing part and a second housing part, the first housing part being connected to the second housing part to seal the pressure chamber in a pressure-tight manner A sensor chip is arranged in the pressure chamber, substantially surrounded by the medium, and configured to measure a pressure of the medium. The sensor assembly also includes a plurality of connection pins which are fed through the first housing part (carrier) by pressure-tight bushings and which are electrically connected to the sensor chip. The sensor assembly also has stress relieving structures which are configured to mechanically decouple the first housing part and a pressure-sensitive element of the sensor chip.