High Reflective LED Substrate Coating for Light Output
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Solution Overview
Problem
Conventional light emitting diode (LED) packages suffer from optical losses due to less than 100% reflectivity of practical reflector surfaces, leading to absorption of light and heat retention issues, which reduce the overall efficiency and longevity of LED devices.
Innovation Solution
A high reflective coating is applied to the substrate or submount of LED devices, comprising a carrier material with dispersed reflective particles, which redirects back-emitted or scattered light and maintains reflectivity over time, preventing yellow discoloration and degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional reflector surface is used in LED packages, then the structure is simple and easy to manufacture, but light absorption occurs and heat retention issues arise due to less than 100% reflectivity
Solution Approach 1:
The patent applies composite materials by combining a reflective base layer with a transparent protective coating layer. This composite structure maintains high reflectivity while providing durability and resistance to yellowing, thereby reducing light absorption without significantly complicating the manufacturing process.
Solution Approach 2:
The patent changes the optical parameters of the reflector surface by applying a transparent coating with specific refractive index properties. This modification enhances the reflectivity and prevents yellowing over time, addressing light absorption issues while maintaining manufacturing feasibility.
2Productivity
If a reflective coating is applied to maintain reflectivity over time, then light output and emission efficiency are enhanced, but the device complexity increases
Solution Approach 1:
The patent uses a thin transparent protective coating film applied over the reflective surface. This thin film structure maintains high light output efficiency by preventing yellowing and degradation, while adding minimal structural complexity to the substrate.
Solution Approach 2:
The transparent protective coating acts as an intermediary layer between the reflective base and the external environment. It protects the reflective surface from degradation and yellowing, thereby maintaining light output efficiency without significantly increasing device complexity.
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 light output and emission efficiency by minimizing absorption, maintaining reflectivity and color stability, and extending the operational lifespan of LED devices.
Implementation Method 1
A high reflective coating is applied to the substrate or submount of LED devices, comprising a carrier material with dispersed reflective particles, which redirects back-emitted or scattered light
Implementation Method 2
maintains reflectivity over time, preventing yellow discoloration and degradation
Data Source
AI summary
Light emitting devices and methods are disclosed that provide improved light output. The devices have an LED mounted to a substrate, board or submount characterized by improved reflectivity, which reduces the absorption of LED light. This increases the amount of light that can emit from the LED device. The LED devices also exhibit improved emission characteristics by having a reflective coating on the submount that is substantially non-yellowing. One embodiment of a light emitting device according to the present invention comprises a submount having a circuit layer. A reflective coating is included between at least some of the elements of the circuit layer. A light emitting diode mounted to the circuit layer, the reflective coating being reflective to the light emitted by the light emitting diode. In some embodiments, the reflective coating comprises a carrier with scattering particles having a different index of refraction than said carrier material.