Stacked Epitaxial Micro LED Structure for Full-Color Pixels
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Solution Overview
Problem
Micro LED displays face challenges in handling small-sized LEDs, mounting them on display panels, and replacing defective LEDs due to their tiny size, which affects brightness and color purity.
Innovation Solution
A light emitting stacked structure with epitaxial sub-units emitting different wavelength bands and contact parts for applying common voltage and light emitting signals, allowing for increased light emitting area without expanding pixel area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If micro LEDs are arranged on a two-dimensional plane, then the display can implement various colors through subpixels, but the area occupied by each pixel is relatively increased
Solution Approach 1:
The patent transitions from a two-dimensional arrangement of subpixels to a three-dimensional stacked structure where red, green, and blue light-emitting layers are vertically stacked. This vertical stacking allows multiple colors to be emitted from the same horizontal footprint, significantly reducing the pixel area while maintaining full-color display capability.
2Area of stationary object
If the area of each subpixel is reduced to arrange subpixels within a limited area, then the pixel area is reduced, but the brightness deteriorates through reduction in luminous area
Solution Approach 1:
By stacking light-emitting layers vertically, the patent increases the effective luminous area within the same horizontal footprint. Multiple light-emitting layers (red, green, blue) are positioned at different vertical levels, allowing each to contribute to the overall brightness without requiring larger horizontal space, thus maintaining high brightness while reducing pixel area.
Solution Approach 2:
The patent combines multiple light-emitting layers (red, green, blue) into a single integrated stacked structure. This merging allows the light from all layers to be emitted simultaneously through the same aperture, effectively combining their luminous output to maintain high brightness while occupying minimal horizontal space.
3Adaptability or versatility
If individually grown red, green, and blue LED structures are formed on a final substrate, then various colors can be implemented, but the manufacturing complexity increases
Solution Approach 1:
The patent merges the fabrication of red, green, and blue LED structures into a single epitaxial growth process on a common substrate. Instead of separately growing and assembling individual LED structures, all three color layers are formed simultaneously in a stacked configuration, significantly simplifying the manufacturing process while maintaining full-color display capability.
Solution Approach 2:
The patent employs a universal epitaxial growth process that can produce multiple color layers (red, green, blue) with different bandgaps from the same substrate and processing sequence. This multi-functional approach allows a single manufacturing process to create all necessary light-emitting components, eliminating the need for separate fabrication lines for each color.
4Measurement precision
If a large number of micro LEDs are disposed on one substrate, then the display resolution is improved, but the handling and mounting difficulty increases due to the very small size
Solution Approach 1:
The patent combines multiple micro LED structures (red, green, blue) into a single integrated stacked unit that functions as one pixel. This merging reduces the number of discrete components that need to be handled and mounted individually, while still achieving high display resolution through the vertical stacking of multiple light-emitting layers within each pixel.
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
Improves color purity and reproduction, simplifies manufacturing by reducing complexity in connectivity and manufacturing processes, and maintains high brightness by optimizing light transmission between epitaxial sub-units.
Implementation Method 1
a plurality of epitaxial sub-units disposed one over another, each epitaxial sub-unit configured to emit light having different wavelength bands from each other
Data Source
AI summary
A light module including a circuit substrate and a light emitter, the light emitter including a light source configured to generate light and including a first epitaxial layer, a second epitaxial layer, and an active layer, an insulation layer covering the light source, a first electrode electrically connected to the first epitaxial layer, a light guide configured to guide light generated from the light source, a transparent material covering the light source, and an angle controller disposed on the transparent material, in which the light guide has a guide hole filled with the transparent material, and a refractive index of the light guide is different from that of the light source.