Transparent Pane Multi-Layer Coating for Heating and Reflectivity
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Solution Overview
Problem
Existing transparent panes with electrically conductive coatings for motor vehicles do not adequately meet the requirements for improved reflecting properties and heating efficiency while maintaining high transmittance and structural stability.
Innovation Solution
A transparent pane with an electrically conductive coating comprising at least four functional layers, including optically highly refractive materials and silver-containing layers, where the layer thickness and refractive index configuration enhance reflecting properties and heating efficiency, with a total layer thickness of electrically conductive layers ranging from 20 nm to 100 nm and sheet resistances between 0.5 ohm/square to 1 ohm/square.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a simple electrically conductive coating is used, then manufacturing cost is reduced, but reflecting properties and heating efficiency are insufficient
Solution Approach 1:
The patent applies composite materials by creating a multi-layer coating structure comprising alternating layers of dielectric material and optically highly refractive material, with electrically conductive layers embedded within. This composite structure achieves superior heating efficiency and reflecting properties compared to simple single-layer coatings, while maintaining economic producibility through the use of standard materials like silver and common dielectrics.
Solution Approach 2:
The coating is segmented into multiple functional layers with distinct thicknesses and material compositions. The electrically conductive layers are divided into multiple thin layers (5-25 nm each) separated by dielectric and optically highly refractive layers. This segmentation allows optimization of both heating efficiency and light reflection while controlling total silver content to maintain cost-effectiveness.
2Power
If the layer thickness of electrically conductive layers is increased, then heating power is improved, but transmittance decreases
Solution Approach 1:
Instead of using a single thick electrically conductive layer, the patent segments the conductive material into multiple thin layers (5-25 nm each) separated by dielectric and optically highly refractive layers. This segmentation distributes the heating function across multiple interfaces while maintaining high transmittance through the overall structure, achieving adequate heating power without sacrificing optical performance.
Solution Approach 2:
The patent applies different layer thicknesses and material properties at different positions within the coating structure. The optically highly refractive layers with refractive index ≥2.1 are strategically positioned between conductive layers to enhance local light reflection and heating efficiency, while the matching layers with lower refractive index (≤2.1) optimize overall light transmission. This local optimization allows high heating power with maintained transmittance.
3Loss of energy
If a multi-layer coating structure is implemented, then reflecting properties are improved, but device complexity increases
Solution Approach 1:
The patent uses composite materials with specific refractive index characteristics (dielectric layers with n≤2.1 and optically highly refractive layers with n≥2.1) to achieve superior reflecting properties. The alternating high and low refractive index layers create constructive interference for reflected light, enhancing thermal reflection efficiency without requiring excessive layer thickness or complex material compositions.
Solution Approach 2:
The patent optimizes reflecting properties by carefully controlling the refractive index parameter of each layer and the thickness of individual layers. The dielectric layers have refractive index ≤2.1 while optically highly refractive layers have refractive index ≥2.1, creating optimal optical interference conditions. This parameter optimization achieves high reflecting efficiency with a manageable number of layers, balancing performance with manufacturing feasibility.
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 configuration results in high transmittance, color neutrality, and significantly improved reflecting properties, along with adequate heating power and electrical conductivity, suitable for motor vehicle glazing.
Implementation Method 1
at least one layer of optically highly refractive material arranged between two electrically conductive layers comprises a layer of a dielectric material with a refractive index less than or equal to 2.1 and a layer of an optically highly refractive material with a refractive index greater than or equal to 2.1
Implementation Method 2
an electrically conductive layer above the first matching layer
Implementation Method 3
The pane can have an electrical heating function, based on transparent, electrical coatings
Data Source
AI summary
A transparent pane comprising a transparent substrate and an electrically conductive coating on a surface of the transparent substrate is disclosed. The electrically conductive coating comprises four functional layers arranged one atop another. Each functional layer comprises a layer of optically highly refractive material with a refractive index >1.3, a first matching layer above the layer of optically highly refractive material, an electrically conductive layer above the first matching layer, and a second matching layer above the electrically conductive layer. The layer thickness of each conductive layer can be 5 nm to 25 nm and the total layer thickness of all electrically conductive layers can be 20 nm to 100 nm.