LED Phosphor Layer Side Surface Coating for Chromaticity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light-emitting diodes (LEDs) face challenges in achieving uniform color quality and reducing chromaticity inferiorities, particularly due to light emission from side surfaces, which affects the optical characteristics of the device.
Innovation Solution
A light-emitting device with a phosphor layer covering all side surfaces of a light-transmissive substrate, converting blue light to white light, and a method of manufacturing involving transferring and dicing fluorescent material-containing resin to form the phosphor layer, ensuring uniform chromaticity across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a phosphor layer is applied only to the top surface of the substrate, then the manufacturing process is simple, but the color quality is non-uniform due to light emission from side surfaces
Solution Approach 1:
The phosphor layer is extended from the top surface to the side surfaces of the substrate, adding a dimensional aspect to the coating application. This ensures that light emitted from side surfaces also passes through phosphor material, achieving uniform color quality across all emission directions while maintaining manufacturing feasibility through conventional coating techniques.
Solution Approach 2:
The phosphor layer is selectively applied to different surfaces (top and side surfaces) where light emission occurs. This localized application ensures that phosphor conversion is provided exactly where needed - at all light-exiting interfaces - without unnecessarily complicating areas where light does not emit.
2Manufacturing precision
If the phosphor layer covers all side surfaces, then color quality uniformity is improved, but the manufacturing complexity increases
Solution Approach 1:
The solution addresses the increased complexity by extending the phosphor layer application to side surfaces in a systematic manner. The phosphor-containing resin is applied to form a coating that covers both top and side surfaces, creating a unified structure that manages light emission uniformly without requiring multiple separate processing steps.
Solution Approach 2:
The phosphor layer is formed using a composite material consisting of phosphor particles dispersed in a transparent resin matrix. This composite structure allows the phosphor layer to simultaneously provide color conversion functionality and maintain structural integrity on complex substrate geometries including side surfaces, simplifying the overall manufacturing approach.
3Manufacturing precision
If fluorescent material-containing resin is used to form the phosphor layer, then uniform chromaticity is achieved, but the manufacturing process becomes more complex
Solution Approach 1:
The fluorescent material-containing resin forms a composite phosphor layer that uniformly distributes phosphor particles throughout the resin matrix. This composite structure ensures consistent chromaticity across the entire emission surface while allowing the layer to be applied as a unified coating material, simplifying the manufacturing process despite the enhanced performance requirements.
Solution Approach 2:
The phosphor layer thickness is controlled within a specific range (1-10 micrometers) to optimize both chromaticity uniformity and manufacturing feasibility. This parameter control ensures that the fluorescent material-containing resin provides uniform phosphor conversion without requiring excessively complex manufacturing 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
The solution enhances the optical characteristics by achieving uniform color quality and improved chromaticity, allowing for high-quality white light emission from both the top and side surfaces of the LED device.
Implementation Method 1
a phosphor layer covering all the side surfaces of the light-transmissive substrate... converting blue light to white light
Data Source
Figure 1~2
Figure 3A~3C
Figure 3D~3F
AI summary
A light-emitting device (1) including a phosphor layer (200), a light-emitting device package employing the light-emitting device (1), a method of manufacturing the light-emitting device (1), and a method of packaging the light-emitting device (1) are described. The light-emitting device (1) includes: a light-transmissive substrate (10) having a top surface (11), a bottom surface (13), and side surfaces (12); a light-emitting unit (20) formed on the top surface (11) of the light-transmissive substrate (10); and a phosphor layer (200) covering all the side surfaces (12) of the light-transmissive substrate (10). According to the present invention, chromaticity inferiorities of light emitted from side surfaces of a substrate may be reduced.