Phosphor-Converted LED Scattering Ring Design
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Solution Overview
Problem
Conventional LED light sources with phosphor conversion face challenges in achieving uniform light emission due to settling of phosphor particles and high packaging costs, leading to variations in color and reduced light output, as they require precise control of phosphor layer thickness and uniformity, which is difficult to automate and costly to manufacture.
Innovation Solution
A light source design incorporating a die bonded to a substrate with a scattering ring made of transparent material containing suspended particles, where the scattering ring is formed by capillary action, scattering light from the side surfaces into a phosphor conversion component, ensuring uniform light distribution and reducing packaging costs by eliminating the need for separate reflectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a reflector cup is used to redirect side light, then light output is improved, but packaging cost increases
Solution Approach 1:
The patent merges the reflector function with the phosphor substrate by integrating a reflective layer directly onto the substrate surface. This eliminates the need for a separate reflector cup structure, reducing packaging complexity and cost while maintaining the light redirecting function. The reflective layer is applied as a thin coating rather than a bulky three-dimensional structure.
Solution Approach 2:
The patent extracts the essential reflective function from the complex reflector cup structure and isolates it as a simple reflective layer on the substrate. This separates the light redirecting function from the structural support function, allowing the substrate to serve dual purposes while reducing overall packaging complexity.
2Stability of the object's composition
If phosphor layer thickness is controlled for uniform color, then color uniformity is improved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces the mechanical approach of precisely controlling phosphor layer thickness with a chemical/suspension approach. Phosphor particles are suspended in a carrier material that is applied as a slurry or paste. The particle distribution and layer formation are controlled through the properties of the suspension (viscosity, particle size distribution, solvent evaporation rate) rather than mechanical thickness control, simplifying the manufacturing process.
Solution Approach 2:
The patent changes the parameters of the phosphor application process by using a suspended particle system with controlled viscosity and particle size distribution. Instead of controlling thickness through mechanical means, the process controls particle settling and distribution through suspension chemistry parameters, making the process more manufacturable while maintaining color uniformity.
3Stability of the object's composition
If phosphor particles are suspended in carrier material, then phosphor distribution is improved, but particle settling occurs
Solution Approach 1:
The patent applies preliminary action by adding dispersants and viscosity modifiers to the carrier material before phosphor particle settling occurs. These additives are pre-mixed into the suspension to prevent aggregation and control settling rate, ensuring uniform phosphor distribution throughout the applied layer before curing or drying.
Solution Approach 2:
The patent uses a composite carrier material system that combines multiple components: base material (epoxy, silicone, or polymer), dispersants (surfactants), viscosity modifiers, and potentially thixotropic agents. This composite formulation maintains phosphor particle suspension stability while allowing for uniform application and controlled curing.
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 provides a more uniform and cost-effective light source with improved light extraction efficiency, as the scattering ring ensures consistent phosphor thickness and reduces manufacturing complexity, allowing for the production of compact, high-efficiency white LEDs with reduced color variation across the light-emitting surface.
Implementation Method 1
The scattering ring surrounds the side surfaces of the die and is positioned in the space such that a portion of the light emitted from the side surfaces of the die is scattered into the light conversion component by the scattering ring
Implementation Method 2
wherein said transparent material has a liquid precursor that wets said bottom surface of said light conversion component and said mounting substrate, and wherein said liquid precursor is drawn into said space by capillary action
Implementation Method 3
The light conversion component includes a layer of luminescent material that converts light of the first wavelength to light of a second wavelength
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
A light source [30] and method for fabricating the same are disclosed. The light source includes a die [31], a light conversion component [33], and a scattering ring [34]. The die emits [31] light of a first wavelength through a top surface of the die and one or more side surfaces of the die, and is bonded to a mounting substrate [32]. The light conversion component [33] converts light of the first wavelength to light of a second wavelength, the light conversion component having a bottom surface bonded to the top surface of the die [31]. The light conversion component [33] has lateral dimensions such that a space exists around the die, the space being bounded by the substrate [32] and the light conversion component [33]. The scattering ring [34] is positioned in the space such that a portion of the light emitted from the side surfaces of the die[31] is scattered into the light conversion component [33].