Coaxial Multi-Color Micro-LED Stacking for High-Resolution Brightness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LED display technologies face challenges in balancing pixel size, resolution, and brightness, particularly in high-definition displays, with inefficient fabrication processes and reliability issues, leading to high power consumption and complex manufacturing.
Innovation Solution
A multi-color LED structure is designed with vertically stacked micro-LEDs of different colors, sharing a common electrode, and utilizing transparent bonding layers and reflection layers to enhance light emission efficiency and reduce substrate-related issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate monochromatic LEDs are fabricated at different non-overlapping zones within the pixel area, then multiple colors can be achieved, but the effective illumination area within each pixel is reduced and resolution deteriorates
Solution Approach 1:
The patent transitions from a two-dimensional planar arrangement of separate monochromatic LEDs to a three-dimensional vertically stacked configuration. Multiple LED layers (red, green, blue) are stacked along the vertical axis, allowing color reproduction without lateral separation. This dimensional change enables full-color display while maintaining high pixel resolution, as the vertical stacking eliminates the need for non-overlapping zones that would reduce effective illumination area.
Solution Approach 2:
The patent implements a nested structure where multiple LED layers are vertically integrated within a single pixel footprint. Each LED layer (emitting different colors) is positioned at different heights, with upper layers potentially positioned within or adjacent to the projection of lower layers. This nesting approach allows multiple color-emitting elements to occupy the same lateral space, maximizing illumination area while maintaining color versatility.
2Manufacturing precision
If pixel size is reduced to achieve high resolution, then resolution improves, but brightness decreases
Solution Approach 1:
By stacking multiple LED layers vertically, the patent increases the total light-emitting volume within each pixel without increasing the lateral pixel area. This allows smaller pixel footprints (higher resolution) to still contain sufficient light-emitting material across multiple layers to maintain or enhance brightness. The vertical dimension compensates for the reduced lateral dimensions.
Solution Approach 2:
The patent employs a composite structure combining multiple LED layers with different emission colors (red, green, blue) stacked vertically. This composite arrangement allows each layer to contribute to the overall brightness while maintaining color purity. The combined light output from multiple layers provides higher total luminance than a single layer could achieve in the same or smaller area.
3Ease of manufacture
If conventional fabrication processes are used for integrating micro LEDs with pixel driver circuitry, then manufacturing can be performed, but the process is inefficient, costly, and unreliable
Solution Approach 1:
The patent integrates multiple LED layers, transparent bonding layers, reflection layers, and electrode structures into a single vertically stacked unit that can be fabricated as one integrated structure. This merging of previously separate components (individual LEDs, bonding layers, electrodes) into a unified stacked architecture simplifies the manufacturing process, reduces assembly steps, and improves reliability by eliminating interfaces between separately fabricated components.
Solution Approach 2:
The transparent bonding layers serve multiple functions simultaneously: they provide mechanical bonding between LED layers, allow light transmission from lower to upper layers, and can serve as part of the electrical connection structure. The reflection layers similarly provide optical reflection to enhance light extraction while potentially serving as electrical isolation or connection elements. This multi-functionality reduces the number of separate components needed.
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 multi-color LED design improves brightness and resolution while maintaining low power consumption, enabling efficient fabrication and reliable operation for high-definition displays.
Implementation Method 1
a first transparent bonding layer between the red light LED structure and the green light LED structure, and a second transparent bonding layer between the green light LED structure and the blue light LED structure
Implementation Method 2
utilizing transparent bonding layers and reflection layers to enhance light emission efficiency
Data Source
AI summary
A method for fabricating a single pixel multi-color micro light-emitting diode device for a display panel comprises providing a substrate supporting a pixel driver, forming a metal bonding layer on top of the substrate, fabricating a first LED structure layer on top of the metal bonding layer, and fabricating a second LED structure layer on top of the first LED structure layer. The method further includes coating a first-type electrode to contact a lower portion of the first LED structure layer, a lower portion of the second LED structure layer, and the metal bonding layer, respectively. The first-type electrode electrically connects the pixel driver to the lower portion of the first LED structure layer and the lower portion of the second LED structure layer through the metal bonding layer.