LED Package Reflective Structure Height for Light Extraction
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Solution Overview
Problem
Conventional LED package structures suffer from poor luminous efficiency and the yellow-ring phenomenon due to the complete obstruction of side light output surfaces by reflective structures, leading to inefficient light emission.
Innovation Solution
The LED package structure features a reflective structure with a top reflecting surface positioned higher than the light input surface and lower than the top light output surface, allowing for partial emission of light from the side light output surface and incorporating a light-permeable body to enhance light guiding, while the wavelength conversion layer is surrounded by the reflective structure without complete obstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the reflective structure completely surrounds the wavelength conversion layer with its top reflecting surface flush with the top light output surface, then the packaging structure is compact and simple, but the side light output surface is completely obstructed causing poor luminous efficiency and yellow-ring phenomenon
Solution Approach 1:
The reflective structure is designed to partially surround the wavelength conversion layer rather than completely enclosing it. The top reflecting surface is positioned at a height lower than the top light output surface of the wavelength conversion layer, creating a partial obstruction that allows side light emission while maintaining reflectivity benefits. This partial action resolves the contradiction by sacrificing complete enclosure to enable side light output and improve luminous efficiency.
2Volume of moving object
If the top reflecting surface is positioned at the same level as the top light output surface, then the packaging structure is compact, but light cannot be emitted from the side light output surface resulting in poor light uniformity
Solution Approach 1:
The solution addresses the light uniformity issue by considering light emission in multiple directions and dimensions. By positioning the top reflecting surface at a lower height than the top light output surface, the invention enables light to escape not only in the upward direction but also in lateral directions from the side light output surface. This dimensional change in light emission paths improves overall light uniformity while maintaining a compact package structure.
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 configuration enhances luminous efficiency, reduces the yellow-ring phenomenon, and achieves uniform light distribution, making the LED package suitable for applications like automobile lamps with improved brightness and beam angle.
Implementation Method 1
The reflective structure has an inner reflecting surface surrounding the light emitting unit and the wavelength conversion layer
Implementation Method 2
when a light generated by the light emitting unit 20 passes through the wavelength conversion layer 40, color of the light is converted into another color
Data Source
AI summary
A light emitting diode package structure includes a substrate, a light emitting unit, a wavelength conversion layer, and a reflective structure. The light emitting unit and the reflective structure are disposed on a mounting surface of the substrate. The wavelength conversion layer is disposed on the light emitting unit. The wavelength conversion layer has a light input surface, a top light output surface opposite to the light input surface, and a side light output surface connecting the light input surface and the top light output surface. The reflective structure surrounds the light emitting unit and the wavelength conversion layer. The reflective structure has a top reflecting surface located on a top of the reflective structure, and a height position of the top reflecting surface is higher than a height position of the light input surface and lower than a height position of the top light output surface.