Infrared Sensor Reflection Film Segmentation for Heat Escape Control

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Solution Overview

Problem

Conventional infrared sensors face issues with heat escape from the infrared reflection film to the wiring and terminal electrodes, leading to temperature measurement errors due to uneven wiring lengths and widths, which affect the accuracy of temperature detection.

Innovation Solution

The design includes an insulating film with patterned terminal electrodes, heat sensitive elements, and patterned wirings, where the infrared reflection film covers the second heat sensitive element while avoiding the second pattern wirings, and expands between terminal electrodes, with cut portions to prevent heat escape, and a thermal coupling portion near the first pattern wirings for efficient heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the infrared reflection film is formed on the entire surface of the compensation side, then the heat sensitive element can be effectively protected and infrared radiation can be reflected, but heat conducted from the detection side escapes to the wiring film and terminal electrode through the infrared reflection film, causing temperature measurement errors

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidheat escape to wiring
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The infrared reflection film is segmented into multiple regions with different functions: a light receiving region that allows infrared radiation to pass through to the first heat sensitive element, and a reflection region that reflects infrared radiation back to the second heat sensitive element. This segmentation enables the film to simultaneously perform heat reflection and prevent heat escape to wiring, resolving the contradiction between measurement accuracy and energy loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the infrared reflection film are assigned different optical properties: the light receiving region has high infrared transmittance while the reflection region has high infrared reflectance. This local differentiation allows each region to optimize its function, with the reflection region preventing heat escape to the wiring film and terminal electrode, thereby improving temperature measurement accuracy without causing energy loss.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the infrared reflection film covers the wiring film region, then manufacturing is simplified, but heat conducted from the detection side is transferred to the wiring film and escapes from the terminal electrode, reducing measurement precision

Engineering Contradiction:
Improveinfrared reflection film formationVSAvoidtemperature detection accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The infrared reflection film is divided into a light receiving region and a reflection region, with the reflection region specifically positioned to cover the second heat sensitive element while avoiding direct coverage of the wiring film and terminal electrode. This segmentation prevents heat escape paths while maintaining manufacturing feasibility through a single film structure with differentiated regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The insulating film serves as an intermediary layer between the infrared reflection film and the wiring film, providing thermal isolation that prevents heat conducted through the infrared reflection film from reaching the wiring film and terminal electrode. This intermediary structure enables the infrared reflection film to be positioned closer to the wiring without causing heat escape, thereby maintaining both manufacturing ease and measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces heat loss to the wirings, offsets the influence of wiring unevenness, and enhances the accuracy of temperature detection, ensuring high responsiveness and precision in measuring temperatures of heating rollers and similar devices.

Implementation Method 1

an infrared reflection film that faces the second heat sensitive element and is provided on the other surface of the insulating film

Methodology Applied
Scientific EffectInfrared reflection: Reflection

Implementation Method 2

measures the temperature by receiving radiant heat thereof

Methodology Applied
Scientific EffectThermal radiation detection: Thermal Radiation

Implementation Method 3

heat conducted from a detection side to the compensation side is transferred from the infrared reflection film to the wiring film on the compensation side

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3605041B1Infrared sensor
Publication Date: 2023.12.06 MITSUBISHI MATERIALS CORP
  • EP3605041B1 patent drawingFigure 1
  • EP3605041B1 patent drawingFigure 2(a)~2(b)
  • EP3605041B1 patent drawingFigure 3

AI summary

Provided is an infrared sensor in which escape of heat from an infrared reflection film to a wiring on a compensation side can be curbed and high accuracy can be achieved. The infrared sensor according to the present invention includes an insulating film 2, a pair of first terminal electrodes 4A, a pair of second terminal electrodes 4B, a first heat sensitive element 5A, a second heat sensitive element 5B, a pair of first pattern wirings 6A and a pair of second pattern wirings 6B that are patterned on one surface of the insulating film, a light receiving region that is provided on the other surface of the insulating film and faces the first heat sensitive element, and an infrared reflection film 8 formed on the other surface of the insulating film to cover at least a region facing the second heat sensitive element while avoiding the light receiving region, wherein the infrared reflection film expands around the region facing the second heat sensitive element while avoiding a region facing the pair of second pattern wirings.