Physical Quantity Sensor Groove Segmentation for Leakage Vibration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Physical quantity sensors face sensitivity issues due to parasitic capacitance and environmental fluctuations, particularly from leakage vibration and leakage force affecting the movable electrode, leading to unstable detection characteristics.

Innovation Solution

Incorporating groove portions on the outer edge of the sensor element, arranged in specific directions to alleviate the transmission of leakage vibration and leakage force, thereby stabilizing the electrical characteristics and reducing thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an outer peripheral portion is provided on the outer periphery of the sensor element to fix the potential and prevent parasitic capacitance, then the sensor sensitivity is improved, but leakage vibration and leakage force are transmitted from the outer peripheral portion to the movable portion, causing detection characteristics to fluctuate

Engineering Contradiction:

Improvesensor sensitivityVSAvoiddetection characteristics stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The outer peripheral portion is divided into multiple segments by grooves arranged in a specific pattern, creating isolated regions that prevent the transmission of leakage vibration and force while maintaining the shielding effect against parasitic capacitance

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The grooves act as intermediary elements between the outer peripheral portion and the sensor element, absorbing and blocking the transmission of harmful vibrations and forces while allowing the outer peripheral portion to maintain its potential-fixing function

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the outer peripheral portion is made rigid to maintain structural stability, then the sensor element is well-supported, but thermal stress accumulates and causes detection characteristics to fluctuate

Engineering Contradiction:

Improvestructural stabilityVSAvoiddetection characteristics stability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The outer peripheral portion is segmented by grooves that create expansion joints, allowing thermal expansion and contraction without accumulating stress, while the overall structure remains stable through the distributed segmentation pattern

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The grooves change the mechanical parameters of the outer peripheral portion by introducing compliance and flexibility, allowing thermal stress to be accommodated through elastic deformation rather than rigid constraint

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10408856B2Electronic device, method of manufacturing electronic device, physical quantity sensor, electronic apparatus and moving object

Publication Date: 2019.09.10 SEIKO EPSON CORP

AI summary

A physical quantity sensor includes a first sensor element, an outer edge portion arranged on at least a portion of the outer periphery of the first sensor element, in which a first groove portion extending in a first direction is provided on the outer edge portion when the outer edge portion is seen in plan view.