Pressure Sensor Heat Insulation Chamber Condensation Control

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Solution Overview

Problem

Conventional pressure sensors using a sensor chip as the pressure detection element face issues with condensation of water vapor permeating the protective member, leading to potential disconnection and corrosion, especially when the temperature of the protective member falls below that of the gas being measured.

Innovation Solution

The pressure sensor design includes a pressure measurement chamber, a sensor support with a support surface for the sensor chip, and a protective member, along with a heat insulation chamber and a gas passage that communicates with the pressure measurement chamber, to prevent temperature drops and condensation around the sensor chip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the protective member covers the sensor chip to prevent corrosion, then the sensor chip is protected from chemical damage, but water vapor permeates the protective member and condenses on the sensor chip when the protective member temperature falls below the gas temperature, causing electrolytic corrosion

Engineering Contradiction:

Improveprotection of sensor chipVSAvoidcondensation of water vapor

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A heat insulating chamber is introduced as an intermediary structure between the protective member and the sensor chip. This chamber prevents direct thermal transmission from the gas to the sensor chip, maintaining the sensor chip temperature above the dew point and preventing water vapor condensation while preserving the protective function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct thermal contact (mechanical heat transfer) with thermal insulation (heat insulating chamber). This substitution prevents the temperature drop that causes condensation while maintaining the protective enclosure structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the sensor chip is used as the pressure detection element, then the degree of freedom in design is improved and miniaturization is enabled, but the sensor chip becomes vulnerable to condensation and corrosion

Engineering Contradiction:

Improvedesign freedomVSAvoidresistance to condensation and corrosion

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The sensor chip is nested within multiple protective layers: first within the protective member that prevents direct chemical contact, and then the entire assembly is placed within the heat insulating chamber that prevents condensation. This nested structure provides both design flexibility and environmental protection.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent uses a composite protective structure combining the protective member (for chemical resistance) and the heat insulating chamber (for thermal protection). This composite approach addresses both corrosion and condensation issues while maintaining miniaturization benefits.

Inventive Principle:

Principle #40Composite materials

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

This configuration effectively suppresses the condensation of water vapor on the sensor chip, preventing electrolytic corrosion and maintaining the integrity of the pressure measurement, even under varying temperature conditions.

Implementation Method 1

a heat insulation chamber which faces a back surface opposite to the support surface of the sensor support

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

a gas passage which communicates with the heat insulation chamber and the pressure measurement chamber

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

there is a risk that water vapor permeating the protective member from a gas to be measured condenses on the periphery of the sensor chip

Methodology Applied

Scientific EffectPermeation: Permeation

Implementation Method 4

water vapor permeating the protective member from a gas to be measured condenses on the periphery of the sensor chip

Methodology Applied

Scientific EffectCondensation: Condensation

Data Source

PatentUS10788388B2Pressure sensor

Publication Date: 2020.09.29 ASTEMO LTD

AI summary

Provided is a pressure sensor that uses a sensor chip as a pressure measurement element and can suppress condensation around the sensor chip of water vapor permeating a protective member from a gas to be measured. The pressure sensor includes a pressure measurement chamber into which a gas to be measured is introduced; a sensor chip that faces the pressure measurement chamber; a sensor support that has a support surface supporting the sensor chip; and a protective member that covers the sensor chip. The pressure sensor also includes a heat insulation chamber that faces a back surface opposite to the support surface of the sensor support; and a gas passage that communicates the heat insulation chamber and the pressure measurement chamber.