LED Package Phosphor Layer Thickness Gradient
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Solution Overview
Problem
Conventional LED packages with uniform phosphor layers face inefficiencies in light emission distribution, as the phosphor layer thickness and design do not effectively manage light radiation from the blue LED chip, leading to suboptimal fluorescent conversion across the emitting angle.
Innovation Solution
The LED package incorporates a phosphor layer with a main portion and an extending portion, where the main portion is uniformly thick and covers the central emitting angle, while the extending portion, with a larger average thickness, extends from the bottom end of the main portion and is designed to capture light radiating towards the periphery, optimizing light conversion and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a uniform phosphor layer is used, then the manufacturing process is simple, but the light emission distribution is inefficient
Solution Approach 1:
The phosphor layer is designed with different thicknesses in different regions: a first thickness in the central region and a second thickness (greater than the first) in the peripheral region. This local variation optimizes light conversion efficiency across different emission angles while maintaining effective manufacturing processes.
2Productivity
If the phosphor layer thickness is increased, then the fluorescent conversion for peripheral light is improved, but the uniformity of light emission is reduced
Solution Approach 1:
The phosphor layer implements spatially varying thickness: a first thickness for central light conversion and a second greater thickness for peripheral light conversion. This local differentiation ensures optimal fluorescent conversion across the entire emission angle while maintaining overall light emission uniformity through targeted thickness optimization in specific regions.
3Productivity
If a non-uniform phosphor layer is used, then the light radiation management is improved, but the manufacturing complexity increases
Solution Approach 1:
The phosphor layer structure comprises a substrate and phosphor material distributed with varying concentrations: higher phosphor concentration in the peripheral region and lower concentration in the central region. This local quality variation optimizes light radiation management for different emission angles while maintaining a relatively simple overall structure that can be manufactured using conventional processes.
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
This design enhances light emission efficiency by ensuring uniform fluorescent conversion across the emitting angle, improving the overall light output and distribution of the LED package.
Implementation Method 1
a phosphor layer with a main portion and an extending portion, where the main portion is uniformly thick and covers the central emitting angle, while the extending portion, with a larger average thickness, extends from the bottom end of the main portion and is designed to capture light radiating towards the periphery, optimizing light conversion and distribution
Data Source
AI summary
The present invention is related to a light emitting diode (LED) package. The LED package includes a blue LED chip, a first electrode, a second electrode and a phosphor layer. The phosphor layer covers an outer periphery of the blue LED chip, except a bottom surface of the blue LED chip. The phosphor layer is mixed by yellow fluorescent powder and glue. The phosphor layer includes a main portion corresponding to a central portion of an emitting angle of the blue LED chip and an extending portion corresponding to a periphery of the emitting angle. An average thickness of the main portion is larger than the thickness of the extending portion.