Low-Emissivity Coating with Segmented TCO Layers for Bending Resistance
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Solution Overview
Problem
Existing low-emissivity coatings on substrates, particularly glass, face challenges in resistance to bending and corrosion, which affect their durability and performance in various applications such as vehicle glazing and building insulation.
Innovation Solution
A substrate coated with a stack of thin layers comprising two or more transparent electroconductive oxide layers separated by a dielectric intermediate layer, with an oxygen barrier layer on top, and optionally additional layers for adhesion and optical properties, to enhance flexibility and corrosion resistance without using metallic layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a single layer of transparent electroconductive oxide is used, then the structure is simple, but the resistance to bending and corrosion is insufficient
Solution Approach 1:
The patent divides a single TCO layer into multiple separate TCO layers (at least two layers) separated by dielectric intermediate layers. This segmentation allows each layer to bear mechanical stress independently, improving overall resistance to bending and corrosion while maintaining the necessary electrical and optical properties through the cumulative effect of multiple layers.
Solution Approach 2:
The patent creates a composite stack structure combining TCO layers with dielectric intermediate layers and oxygen barrier layers. This composite approach integrates materials with different properties - TCO layers provide electrical conductivity and low emissivity, dielectric layers provide mechanical separation and stress distribution, and oxygen barrier layers provide corrosion protection - achieving superior overall performance.
2Reliability
If metallic layers are used to improve conductivity, then electrical performance is enhanced, but resistance to corrosion and bending deteriorates
Solution Approach 1:
The patent optimizes the thickness parameters of TCO layers (20-80 nm each) and dielectric intermediate layers (at most 50 nm) to achieve the desired electrical conductivity and low emissivity while maintaining mechanical flexibility and corrosion resistance. By carefully controlling these dimensional parameters, the patent achieves reliable electrical performance without using metallic layers that would compromise durability.
Solution Approach 2:
The patent introduces dielectric intermediate layers as intermediaries between TCO layers. These intermediate layers mediate the mechanical stress distribution and provide corrosion protection while allowing electrical field penetration, thus maintaining electrical conductivity without requiring metallic layers that would reduce corrosion and bending resistance.
3Stability of the object's composition
If the dielectric intermediate layer is made thicker, then the separation between TCO layers is improved, but the overall emissivity increases
Solution Approach 1:
The patent precisely controls the thickness of dielectric intermediate layers to be at most 50 nm (preferably 30 or 20 nm). This parameter optimization ensures sufficient separation between TCO layers for mechanical stability and stress distribution, while keeping the layer thin enough to maintain low emissivity by allowing adequate infrared transmission between the TCO layers.
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 achieves improved resistance to bending and corrosion while maintaining low emissivity, allowing for flexible design and manufacturing, and effectively managing thermal and optical properties in applications like vehicle glazing and building insulation.
Implementation Method 1
at least one dielectric intermediate layer whose physical thickness is at most 50 nm
Implementation Method 2
at least one oxygen barrier layer above the layer based on a transparent electro-conductive oxide furthest from the substrate
Implementation Method 3
Low-emissive coatings deposited on substrates, particularly glass, have infrared, and therefore heat, reflection properties
Implementation Method 4
heat to be retained within the passenger compartment
Data Source
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AI summary
The subject of the invention is a material comprising a substrate (1) coated over at least one portion of at least one of its faces with a thin-film multilayer comprising at least two layers based on a transparent electrically conductive oxide (2, 3) separated by at least one intermediate dielectric layer (4), the physical thickness of which is at most 50 nm, no metallic layer being placed between said layers based on a transparent electrically conductive oxide (2, 3), said multilayer also comprising at least one oxygen barrier layer (6) on top of the layer based on a transparent electrically conductive oxide (2) furthest away from the substrate (1), each layer based on a transparent electrically conductive oxide (2, 3) having a physical thickness within a range extending from 20 nm to 80 nm.