Ultra-thin Pressure Sensor with Cavity Partition Wall
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Solution Overview
Problem
Conventional pressure sensors face challenges in miniaturization and detection sensitivity due to low process compatibility with circuit units, requiring separate fabrication and complex manufacturing processes.
Innovation Solution
A pressure sensor design featuring a substrate with a cavity and partition wall, a substrate insulation layer, and a sensing unit with resistors, where the encapsulation layer covers the sensing unit, allowing for improved sensitivity and miniaturization through a method involving etching, insulation film formation, and cavity creation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional bulk micromachining and substrate adhesion methods are used, then pressure sensor functionality is achieved, but device size and thickness cannot be sufficiently reduced
Solution Approach 1:
The substrate is segmented by forming a cavity that divides it into upper and lower portions, with the sensing unit positioned on the upper substrate. This segmentation enables miniaturization while maintaining structural integrity and simplifying the manufacturing process through localized fabrication.
Solution Approach 2:
The invention transitions from conventional planar substrate structures to a three-dimensional configuration with a cavity extending through the substrate. This dimensional change allows the sensing unit to be positioned in a specific spatial arrangement that reduces overall sensor thickness while maintaining functionality.
2Device complexity
If separate fabrication of circuit units is performed, then process compatibility issues are avoided, but device complexity and manufacturing steps increase
Solution Approach 1:
The sensing unit and circuit units are integrated on the same substrate, merging previously separate fabrication processes into a unified flow. This integration improves process compatibility and reduces device complexity while maintaining manufacturing precision through coordinated patterning and material deposition steps.
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 design results in an ultra-miniature and ultra-thin pressure sensor with enhanced detection sensitivity, enabling efficient pressure measurement while simplifying the manufacturing process by integrating the sensing unit and encapsulation layer.
Implementation Method 1
The piezo-resistive type pressure sensor detects variation of a resistance component according to stress occurrence of a piezo-resistive material provided on an upper portion of a sensing thin film to measure the pressure by deformation of the sensing thin film.
Implementation Method 2
The capacitive type pressure sensor detects variation between values of capacitances of a sensing electrode varied by the pressure and a fixed reference electrode to measure the pressure.
Data Source
AI summary
Provided is a pressure sensor including a substrate having a cavity therein, a partition wall disposed in the substrate to surround the cavity, a substrate insulation layer disposed on the top surface of the substrate to cover the cavity, a sensing unit disposed on the substrate insulation layer, and an encapsulation layer disposed on the substrate insulation layer to cover the sensing unit. The cavity may extend from a top surface toward a bottom surface of the substrate, the partition wall may have an inner sidewall exposed by the cavity, and at least a portion of the sensing unit may overlap the cavity when viewed in a plan view.