Transparent Heating Element with Removable Substrate for Automotive Glass

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Solution Overview

Problem

Existing heating elements for automotive glass struggle with achieving effective heating while maintaining optical clarity, as methods either result in high resistance at low voltages or are visually noticeable due to thick conductive lines, and refractive index differences between films cause distortion.

Innovation Solution

A conductive heating pattern is formed on a transparent substrate without a remaining transparent base, using a bonding film with specific properties and an adhesive film that reduces adhesive strength, allowing for the removal of additional films between substrates, thus preventing view distortions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a transparent conductive oxide film such as ITO is used to form a conductive film on the glass surface, then optical transparency is improved, but heating value at low voltages deteriorates due to relatively high resistance value

Engineering Contradiction:
Improveoptical transparencyVSAvoidheating value at low voltages
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent uses a composite structure consisting of a transparent substrate, bonding films, and a metal pattern heating line. This composite approach combines the optical transparency of glass with the electrical conductivity of metal, achieving both transparency and effective heating at low voltages without relying solely on transparent conductive oxide films

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent extracts the heating function from the transparent conductive film concept and implements it through a separate metal pattern layer. By separating the heating function into a dedicated metal pattern, the system achieves low-voltage heating capability while maintaining optical transparency through the bonding films and substrate

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If a thick tungsten wire is used for heating, then heating value at low voltages is improved, but visual appearance deteriorates due to the tungsten line being visually noticeable

Engineering Contradiction:
Improveheating value at low voltagesVSAvoidvisual appearance
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies local quality by using a metal pattern with locally optimized thickness and configuration. The metal pattern provides sufficient conductivity for low-voltage heating in specific areas while maintaining thin dimensions (18 micrometers or less) to minimize visual noticeability, achieving both heating performance and aesthetic appearance

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs thin film technology for the metal pattern layer, creating a heating element that is visually imperceptible. The thin film structure ensures that the heating line does not distort viewed objects while providing adequate electrical conductivity for effective heating at low voltages

Inventive Principle:
Principle #30Flexible shells and thin films

3Adaptability or versatility

If a PET film is inserted between two PVB films to form a heating pattern, then heating functionality is improved, but optical performance deteriorates due to distortion from refractive index differences

Engineering Contradiction:
Improveheating functionalityVSAvoidoptical performance
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent extracts the PET film from the final product structure, using it only as a temporary substrate for forming the metal pattern. After the metal pattern is created, the PET film is removed, eliminating the source of refractive index distortion while preserving the heating functionality provided by the metal pattern

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses bonding films as intermediaries to connect the metal pattern to the PVB films. These bonding films provide the necessary adhesive function without introducing refractive index differences that would cause visual distortion, serving as optimal mediators between the heating element and the glass bonding layers

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

The solution enables efficient heating at low voltages with minimal visual impact and prevents refractive index-related distortions, providing a heating element with excellent optical properties and heating performance.

Implementation Method 1

generating heat from the heating line by applying electricity to both terminals of the heating line, and increasing a temperature of the glass surface therefrom

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

an adhesive film that reduces adhesive strength, allowing for the removal of additional films between substrates

Methodology Applied
Scientific EffectAdhesive strength reduction by external stimulus: Adhesive

Data Source

PatentEP3474628B1Heating element and manufacturing method therefor
Publication Date: 2021.10.13 LG CHEM LTD
  • EP3474628B1 patent drawingFigure 1~2
  • EP3474628B1 patent drawingFigure 3~5
  • EP3474628B1 patent drawingFigure 6

AI summary

The present specification relates to a heating element and a method for manufacturing the same.