LED Primer Nanoscale Metal Oxide Blue Light Diffraction
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Solution Overview
Problem
Luminescence conversion LEDs with conversion layers and casting compounds face issues such as color temperature shifts due to coating thickness, suboptimal wetting leading to adhesion loss, and loss of transparent character when using scattering particles, resulting in non-uniform lighting.
Innovation Solution
A primer with nanoscale metal oxide and isocyanate functional ingredients is applied between the conversion layer and casting compound to enhance adhesion and diffract blue light waves, ensuring uniform color temperature and protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating or potting compound is applied to the LED, then protection against electric shock and environmental factors is improved, but total internal reflection at the air interface is eliminated causing color temperature shift towards higher temperatures
Solution Approach 1:
A primer layer with refractive index n=1.30±0.05 is introduced as an intermediary between the conversion layer and the potting compound. This primer layer restores total internal reflection conditions for blue light while allowing the potting compound to provide electrical protection, thus resolving the contradiction between protection and color temperature maintenance.
2Illumination intensity
If spacers in the form of caps are used to create a defined air gap, then total reflection of blue light is maintained, but the solution becomes complex and not available for many LED types
Solution Approach 1:
The complex spacer structure is replaced by extracting only the essential function - maintaining the refractive index difference - and implementing it through a simple primer layer with specific refractive index properties, thus simplifying the device structure while maintaining blue light reflection.
Solution Approach 2:
Instead of using physical spacers to create an air gap, the solution changes the refractive index parameter of the interface material (primer layer) to n=1.30±0.05, which naturally restores total internal reflection conditions without requiring complex structural modifications.
3Stability of the object's composition
If anti-wetting materials are used on the conversion coating, then adhesion control is achieved, but the protective effect of the potting compound is reduced
Solution Approach 1:
The primer layer's specific refractive index (n=1.30±0.05) and optical properties are optimized to provide both adequate adhesion control and maintain the protective function of the potting compound, avoiding the need for anti-wetting materials that would compromise protection.
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 primer achieves consistent adhesion and uniform warm white light by reflecting blue light waves back into the conversion layer, preventing color temperature shifts and maintaining transparent encapsulation.
Implementation Method 1
to diffract the blue light waves penetrating the conversion layer in such a way that at least a portion of the diffracted blue light waves are reflected at the interface between the primer and the potting compound
Implementation Method 2
The short-wavelength, high-energy blue light excites this luminescent dye, causing it to emit longer-wavelength, lower-energy yellow light
Implementation Method 3
to promote adhesion between the conversion layer of a luminescence conversion LED emitting, among other things, blue light waves, and a colorless or colored, as well as clearly transparent or opaque, potting compound to be applied to it
Data Source
AI summary
The invention relates to luminescence conversion LEDs which are provided with a conversion layer and a colorless or colored, as well as clearly transparent or opaque, potting compound to be applied thereon.To achieve a uniform warm white light color, a primer is specified, firstly for adhesion promotion between the conversion layer of a luminescence conversion LED emitting, among other things, blue light waves and a colorless or colored, as well as clearly transparent or opaque, potting compound to be applied thereon, and secondly for diffracting the blue light waves penetrating the conversion layer such that at least a part of the diffracted blue light waves are reflected at the interface between the primer and the potting compound and pass back through the primer into the conversion layer, wherein the primer comprises a nanoscale metal oxide for diffracting the blue light waves penetrating the layer and is composed of a first component containing the metal oxide and a second component containing an isocyanate-functional component, preferably isocyanate.