Micro LED Dielectric Stack for Narrow Light-Emitting Angles
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Solution Overview
Problem
Micro LEDs in prior art suffer from wide light-emitting angles leading to inconsistent brightness and inaccurate colors due to the inability to install a light-concentrating device, resulting in light mixing and dispersion.
Innovation Solution
A micro LED structure with multiple dielectric layers of gradually shrinking widths and fan-out packaging is employed to concentrate light emission, using layers with varying refractive indices to shrink the light-emitting angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If micro LED uses miniature size, then brightness and contrast are improved, but light-emitting angle becomes too wide causing light mixing and inaccurate colors
Solution Approach 1:
The patent divides the micro LED structure into multiple dielectric layers (first, second, and third dielectric layers) with progressively different refractive indices. Each layer segments the light path control function, with lower layers having lower refractive indices and upper layers having higher refractive indices, working together to progressively narrow the light-emitting angle and prevent color mixing
Solution Approach 2:
The patent changes the refractive index parameter across different dielectric layers to control light propagation. By arranging layers with increasing refractive indices from bottom to top, the structure optimizes total internal reflection at each interface, effectively narrowing the light-emitting angle while maintaining color accuracy
2Power
If micro LED uses miniature size, then device performance is improved, but light-emitting angle cannot be shrunk effectively
Solution Approach 1:
The patent transitions from controlling light emission in a single dimension to three-dimensional control through stacked dielectric layers. Each layer adds a dimensional level of refractive index control, creating a progressive light narrowing effect that effectively shrinks the light-emitting angle while maintaining the miniature device performance
3Shape
If multiple dielectric layers with different refractive indices are added, then light-emitting angle is shrunk effectively, but device complexity increases
Solution Approach 1:
The patent implements a nested structure where multiple dielectric layers are stacked concentrically around the light-emitting region. Each dielectric layer is nested within the optical path of the layers below it, with progressively different refractive indices, creating a compact nested configuration that narrows light emission without excessive horizontal expansion
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 effectively shrinks the light-emitting angle, improving brightness consistency and color accuracy by concentrating light emission, addressing issues of inconsistent brightness and inaccurate colors.
Implementation Method 1
A first refractive index of the first dielectric layer is smaller than a second refractive index of the second dielectric layer. The second refractive index is smaller than a third refractive index of the third dielectric layer
Data Source
AI summary
The present invention provides a micro light-emitting diode structure, which comprises: a first light-emitting layer, a second light-emitting layer, a third light-emitting layer, a first dielectric layer, a second dielectric layer, and a third dielectric layer stacked on one another sequentially. The first light-emitting layer, the second light-emitting layer, and the third light-emitting layer are connected electrically by fan-out circuit layers, respectively. A first area of the first dielectric layer is greater than a second area of the second dielectric layer. The second area is greater than a third area of the third dielectric layer. A first refractive index of the first dielectric layer is smaller than a second refractive index of the second dielectric layer. The second refractive index is smaller than a third refractive index of the third dielectric layer. By using this structure, the light-emitting angle of a micro LED can be further shrunk.