Quantum Dot Color Conversion Layer for Small-Pitch Micro-LED Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies face challenges in creating monolithic, full-color micro-LED displays with small pixel sizes (0.5 μm to 5 μm) due to the difficulty in integrating quantum dots with high-performance semiconductor fabrication equipment, and in achieving the precise alignment of green and red quantum dots over blue pixels.
Innovation Solution
A method is developed to fabricate a monolithic, full-color micro-LED display by bonding a color conversion layer containing quantum dots to a monochrome display. The color conversion layer includes pixels with quantum dots tuned to specific wavelengths for creating blue, green, and red colors, and the process is designed to avoid contamination with quantum dots during high-resolution semiconductor processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If quantum dots are integrated during high-performance semiconductor fabrication, then manufacturing precision and alignment are improved, but facility contamination and process complexity increase
Solution Approach 1:
The fabrication process is divided into two separate stages: (1) high-performance semiconductor fabrication for the micro-LED array without quantum dots, and (2) subsequent quantum dot integration after the micro-LED array is completed. This segmentation allows each stage to be optimized independently, avoiding contamination of sensitive fabrication equipment while maintaining precise alignment through registration features.
Solution Approach 2:
Registration features are incorporated into the micro-LED array structure during the initial fabrication stage, before quantum dots are added. These pre-positioned features serve as alignment markers that guide subsequent quantum dot placement, ensuring precise positioning without requiring complex real-time alignment systems during quantum dot integration.
2Object-affected harmful factors
If quantum dots are added post-processing, then facility contamination is avoided, but alignment precision and integration difficulty increase
Solution Approach 1:
Registration features act as intermediary elements between the micro-LED array and quantum dots. These features are fabricated during the semiconductor process and remain on the substrate to serve as alignment markers during subsequent quantum dot integration, enabling precise positioning without direct interaction between quantum dots and sensitive fabrication equipment.
Solution Approach 2:
The registration features create a positional map or template that guides quantum dot placement. By copying the pixel array geometry into the registration feature layer, the system enables accurate quantum dot positioning through pattern matching rather than requiring complex alignment equipment.
3Area of moving object
If small pixel sizes (0.5 μm to 5 μm) are used, then display resolution and density are improved, but quantum dot alignment and integration difficulty increase
Solution Approach 1:
The registration features are designed with local quality variations - larger, more robust features for coarse alignment and finer features for precise positioning. This hierarchical approach to feature design enables accurate alignment even at small pixel dimensions by providing multiple levels of alignment reference.
Solution Approach 2:
The solution moves the alignment problem from the lateral plane to the vertical dimension by using multi-layer registration features. Alignment is achieved through vertical stacking and registration of features across different layers, allowing precise positioning in the lateral direction through vertical reference structures that are less sensitive to small pixel size variations.
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 approach enables the creation of high-efficiency, small-pitch, full-color micro-LED displays that can emit in the blue, red, and green wavelength ranges, overcoming the limitations of existing technologies by allowing quantum dots to be introduced post-processing, thus avoiding contamination of high-resolution facilities.
Implementation Method 1
The color conversion layer includes pixels containing quantum dots which are tuned to appropriate wavelengths to create pixels of different colors. If, for example, the monochrome display emits blue light, then green pixels may be created by illuminating quantum dots tuned to convert blue light into green light.
Data Source
AI summary
Color conversion layers, methods of making color conversion layers, monolithic color, micro-light-emitting diode displays and methods of making monolithic, color, micro-light-emitting diode displays are disclosed.