Light Emitting Device Groove Structure for Light Extraction
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Solution Overview
Problem
Light emitting devices face challenges in maximizing light extraction efficiency due to the light reflecting resin covering the lateral surfaces of the light emitting element, leading to loss of light output.
Innovation Solution
A light emitting device design featuring a package with a recess, a light emitting element, a light-transmissive resin, and a light reflecting resin, where the light-transmissive resin covers the light emitting element and is in contact with the groove surface, preventing the light reflecting resin from covering the lateral surfaces and enhancing adhesion, while the light reflecting resin is formed continuously from the lateral surfaces to the outer edge of the groove to deflect light output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If light reflecting resin is applied to the inner peripheral surface of the recess, then light extraction efficiency is improved, but the light reflecting resin may cover the lateral surfaces of the light emitting element causing light loss
Solution Approach 1:
A groove structure is introduced as an intermediary element between the light emitting element and the light reflecting resin. The groove prevents the light reflecting resin from directly contacting and covering the lateral surfaces of the light emitting element, while still allowing the resin to be applied to the inner peripheral surface of the recess for light extraction enhancement.
Solution Approach 2:
The inner peripheral surface of the recess is segmented into distinct regions: a first region that contacts the light emitting element and a second region that contacts the light reflecting resin. This segmentation is achieved through the groove structure, which creates a clear boundary between areas intended for light emission and areas intended for light reflection.
2Loss of energy
If light-transmissive resin is used to cover the light emitting element, then light extraction is enhanced, but adhesion between resin and package may be insufficient
Solution Approach 1:
The groove structure is formed on the package surface before the light-transmissive resin is applied. This preliminary structural preparation creates a mechanical interlocking feature that enhances adhesion between the resin and package, preventing resin peeling while maintaining light extraction efficiency.
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 effectively prevents light loss by ensuring the light reflecting resin does not cover the lateral surfaces of the light emitting element, thereby maintaining high light extraction efficiency and improving the reliability of the light emitting device.
Implementation Method 1
enhancing adhesion
Implementation Method 2
the light reflecting resin is provided between the inner peripheral surface of the recess and the light-transmissive resin
Data Source
AI summary
A light emitting device includes a package having a recess which includes a bottom surface and an inner peripheral surface around a periphery of the bottom surface. The package includes a first lead to define a first part of the bottom surface, a second lead to define a second part of the bottom surface, and a resin body to provide the inner peripheral surface and a remaining part of the bottom surface. The bottom surface includes a light emitting element mounting region in the first part and a groove surrounding the light emitting element mounting region. A light emitting element is mounted on the light emitting element mounting region. A light-transmissive resin is provided in the recess to be in at least a part of a groove surface. A light reflecting resin is provided between the inner peripheral surface of the recess and the light-transmissive resin.