LED Multi-Film Window for Refractive Index Mismatch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light-emitting diodes with single seal and package layers suffer from reduced light output efficiency due to different refractive indexes affecting the transmission of blue, green, and red wavelengths, leading to diminished light strength when mixing colors to produce white light.
Innovation Solution
A light-emitting diode structure with a transparent window covering layer comprising a first low refractive index layer and a second high refractive index layer, deposited on the outside of the chip using materials like AIN, Al2O3, and SiO2, to enhance light transmission and color adjustment, while maintaining a strong adhesive force and environmental stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single seal and package layer is used, then the structure is simple and easy to manufacture, but the light transmission efficiency is reduced due to different refractive indexes affecting different wavelengths
Solution Approach 1:
The single seal and package layer is segmented into multiple transparent covering layers with different refractive indexes. The patent applies a first transparent covering layer with refractive index 1.4-1.8 and a second transparent covering layer with refractive index 1.8-2.2, allowing different wavelength ranges to pass through more efficiently while maintaining environmental protection
Solution Approach 2:
The patent uses composite material structure by combining multiple transparent covering layers made of different materials (such as SiO2, Si3N4, TiO2) with different refractive indexes. This composite structure optimizes light transmission across different wavelengths while providing environmental stability and adhesion
2Productivity
If multiple transparent covering layers with different refractive indexes are used, then the light transmission efficiency is improved, but the device structure becomes more complex
Solution Approach 1:
The light extraction problem is segmented by dividing the covering layer into multiple functional layers, each optimized for specific wavelength ranges. The first layer (refractive index 1.4-1.8) and second layer (refractive index 1.8-2.2) work together to extract different portions of the light spectrum, achieving over 70% extraction efficiency
Solution Approach 2:
The patent changes the refractive index parameter by using materials with specifically selected refractive indexes (1.4-1.8 for first layer, 1.8-2.2 for second layer). This parameter optimization allows better impedance matching between the LED chip and air, improving light extraction while keeping the overall structure manageable
3Ease of manufacture
If conventional single layer sealing is used, then the manufacturing process is simple, but only up to 50% of generated light can emit from the surface
Solution Approach 1:
The patent replaces the conventional single sealing layer with a composite structure of multiple transparent covering layers having different refractive indexes. This composite material approach enables light extraction efficiency to exceed 50%, with optimal configurations achieving 70% or higher, while still providing effective environmental protection
Solution Approach 2:
The multiple transparent covering layers act as intermediary structures between the LED chip and the external environment. Each layer serves as an optical mediator that facilitates light extraction for different wavelength ranges, overcoming the limitation of direct single-layer sealing
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 multi-film structure significantly increases light output efficiency by optimizing transmission across different wavelengths, ensuring stable and efficient light emission with improved color mixing and environmental resistance.
Implementation Method 1
The first transparent covering layer has low refractive index and the second transparent covering layer has high refractive index to increase the light's taking out efficiency of the light-emitting diode
Data Source
AI summary
A light-emitting diode structure with transparent window covering layer of multiple films includes one (or several) first transparent covering layer(s) and one (or several) second covering layer(s), which are formed on the outside of the light-emitting diode chip. The light-emitting diode chip can emit light in more than two wavelengths to increase the transmission of the different wavelengths and the taking out efficiency of the light-emitting diode. The first transparent covering layer(s) and the second covering layer(s) are deposited each on the other on the outside of the light-emitting diode chip. The surface of the light-emitting diode with the covering layers is smooth. The contacting parts of the first transparent covering layer(s) and the second covering layer(s) are connected by a strong adhesive force and the contacting parts of the covering layer and light-emitting diode chip also are connected by a strong adhesive force.