Pressure Sensor Cantilever Segmentation for Leakage Reduction

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Solution Overview

Problem

Existing pressure sensors face high power consumption and leakage current issues due to constant power supply to piezoresistive elements and adjacent element interactions.

Innovation Solution

A pressure sensor design featuring a cantilever with a communication opening, partitioned displacement detection portions, and branch detection portions with varying resistance values, connected to electrodes, which reduces power consumption and leakage by optimizing resistance values and structural geometry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If power is constantly supplied to pressure-sensitive elements for detection, then detection function is maintained, but power consumption increases

Engineering Contradiction:
Improvedetection functionVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic measurement cycles where the pressure sensor is activated only when needed rather than continuous operation. The control unit determines measurement timing based on operational conditions, enabling the system to maintain detection capability while reducing overall power consumption by keeping the sensor in a low-power state during non-measurement periods.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If multiple pressure-sensitive elements are provided on the diaphragm surface, then detection coverage is improved, but leakage current between adjacent elements increases

Engineering Contradiction:
Improvedetection coverageVSAvoidleakage current
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent divides the pressure-sensitive element into multiple separate regions (first, second, third, and fourth pressure-sensitive elements) that are spatially segmented on the diaphragm surface. Each segment is electrically isolated from the others, allowing independent measurement while preventing leakage current between adjacent elements. This segmentation enables comprehensive pressure detection across different diaphragm regions without the harmful interaction of electrical leakage.

Inventive Principle:
Principle #1Segmentation

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 decreases power consumption, improves detection accuracy, and enhances sensitivity by effectively managing resistance values and stress concentrations, while minimizing leakage between adjacent detection portions.

Implementation Method 1

a pressure sensor which includes a substrate which has a gap portion inside the substrate, a diaphragm portion which configures a portion of an inner wall of the gap portion, and a pressure-sensitive element such as a piezoresistor which is provided on the surface of the diaphragm portion

Methodology Applied
Scientific EffectPiezoresistive effect: Piezoresistive Effect

Implementation Method 2

a cantilever which is disposed so as to close the communication opening in a cantilever state in which a distal end portion of the cantilever is a free end and a proximal end portion thereof is supported by the sensor main body, and which is bent according to a pressure difference between the cavity and the outside of the sensor main body

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3118598B1Pressure sensor
Publication Date: 2020.12.09 SEIKO INSTR INC
  • EP3118598B1 patent drawingFigure 1~2
  • EP3118598B1 patent drawingFigure 3
  • EP3118598B1 patent drawingFigure 4

AI summary

The present invention relates to a pressure sensor (1) which detects variation in pressures, the pressure sensor including a cantilever (4) which is bent according to a pressure difference between the inside and the outside of a cavity in a sensor main body, and an intra-lever gap (21) which is formed on a proximal end portion (4a) of the cantilever. The proximal end portion is partitioned into a first support portion (22) and a second support portion (23) by an intra-lever gap in a second direction (L2) orthogonal to a first direction (L1) in which the proximal end portion and a distal end portion (4b) are connected to each other in plan view. A doped layer (24) which is provided on a portion of the first and second support portions forms a first displacement detection portion (25) and a second displacement detection portion (26). Lengths of the first and second displacement detection portions are shorter than those of the first and second supports along the second direction.