Coated Conversion Material for LED Polymer Housing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in developing polymer compositions for LED housings that can produce white light while maintaining melt stability, color consistency, and meeting industry standards for flame retardancy and optical properties, as existing materials tend to degrade during extrusion, leading to embrittlement and undesirable color shifts.
Innovation Solution
A polymer composition comprising a polymer material and a coated conversion material with specific concentrations of Si, Sr, Ba, Ca, Eu, and other elements, which absorbs a first wavelength range of radiation and emits a second wavelength range, ensuring a luminescence lifetime of less than 10^-4 seconds when the excitation source is removed, thereby producing stable and efficient white light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polymer compositions are used for LED housings, then manufacturing is simpler, but the materials degrade during extrusion causing embrittlement and color shifts
Solution Approach 1:
The patent applies parameter changes by precisely controlling the concentration ranges of multiple elements (Si: 20-1000 ppm, Sr: 10-500 ppm, Ba: 10-500 ppm, Ca: 10-500 ppm, Eu: 0.1-100 ppm, and limiting Al, Co, Fe, Mg, Mo, Na, Ni, Pd, P, Rh, Sb, Ti, Zr to less than 50 ppm each). This compositional parameter optimization stabilizes the polymer during extrusion, preventing degradation, embrittlement, and color shifts while maintaining manufacturability
Solution Approach 2:
The patent uses composite materials by creating a multi-element doped polymer composition that combines conversion materials with specific polymer matrices. This composite approach enhances melt stability and prevents degradation during processing, resolving the contradiction between reliability and ease of manufacture
2Stability of the object's composition
If conversion materials with long luminescence lifetime are used, then energy efficiency improves, but afterglow occurs causing color inconsistency
Solution Approach 1:
The patent applies parameter changes by optimizing the luminescence lifetime parameter to less than 10^-4 seconds through precise control of conversion material composition (specific ratios of Si, Sr, Ba, Ca, Eu). This parameter optimization eliminates afterglow and ensures color consistency while maintaining luminescence efficiency for Energy Star compliance
3Illumination intensity
If polymer compositions are optimized for white light emission, then optical performance improves, but flame retardancy may be compromised
Solution Approach 1:
The patent uses composite materials by integrating multiple functional elements (Si, Sr, Ba, Ca for optical properties; Eu for luminescence control; limited Al, Co, Fe, Mg, Mo, Na, Ni, Pd, P, Rh, Sb, Ti, Zr for stability) within the polymer matrix. This composite structure achieves white light emission requirements while simultaneously meeting flame retardancy standards through synergistic material interactions
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 effectively stabilizes the polymer composition, maintains melt stability, and achieves the desired color perception and flame retardancy, meeting industry requirements for LED lighting products, including the DOE Energy Star rating.
Implementation Method 1
The conversion material is configured to absorb at least a portion of the first wavelength range radiation and emit radiation having a second wavelength range
Implementation Method 2
After the conversion material has been exposed to an excitation source, the conversion material has a luminescence lifetime of less than 10−4 seconds when the excitation source is removed
Implementation Method 3
the conversion material has a luminescence lifetime of less than 10−4 seconds when the excitation source is removed
Implementation Method 4
maintaining melt stability, and achieves the desired color perception and flame retardancy
Implementation Method 5
the conversion material has a luminescence lifetime of less than 10−4 seconds when the excitation source is removed
Data Source
AI summary
In one embodiment, a light emitting device comprises: a lighting element located in a housing, wherein the housing is formed from a polymer composition comprising: a polymer material; and a coated conversion material. The coated conversion material is selected from a coated conversion material, coated yttrium aluminum garnet (YAG) doped with rare earth elements, coated terbium aluminum garnet doped with rare earth elements, coated silicate (BOSE) doped with rare earth elements; coated nitrido silicates doped with rare earth elements; coated nitride orthosilicate doped with rare earth elements, coated oxonitridoaluminosilicates doped with rare earth elements; as well as combinations comprising at least one of the foregoing. After the coated conversion material has been exposed to an excitation source, the coated conversion material has a luminescence lifetime of less than 10−4 seconds when the excitation source is removed.