Micro LED Display Fabrication on Seed Metal for Faster Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing image display devices using micro LEDs are time-consuming and prone to connection defects, leading to reduced yield and high costs, especially for high-definition displays like 4K and 8K, due to the complex transfer process of individually forming and mounting micro LEDs on a substrate with a drive circuit.
Innovation Solution
A method involving the formation of a semiconductor layer with a light-emitting layer on a metal seed layer, which is then patterned to create light-emitting elements, reducing the need for individual transfer and alignment, and using a reflective electrode and insulating films to enhance luminous efficiency and connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If individually-formed micro LEDs are sequentially transferred to a drive circuit substrate, then the display device can achieve high luminance and wide viewing angle, but the transfer process becomes extremely time-consuming and connection defects increase
Solution Approach 1:
The invention segments the light-emitting function from the drive circuit by using a separate semiconductor substrate where multiple light-emitting elements are formed in parallel. This segmented approach allows independent optimization of light emission quality and transfer efficiency, resolving the contradiction between achieving high luminance through individual micro LED formation and maintaining high productivity during transfer.
Solution Approach 2:
The invention performs preliminary action by pre-forming multiple light-emitting elements on a semiconductor substrate before transfer. This allows batch processing of light-emitting elements, significantly reducing the overall transfer time compared to sequential formation and transfer, while maintaining the high luminance characteristics of individually-formed micro LEDs.
2Manufacturing precision
If individually-formed micro LEDs are sequentially transferred to a drive circuit substrate, then precise connection can be achieved, but the complex transfer process increases the risk of connection defects and reduces yield
Solution Approach 1:
The invention segments the manufacturing process into distinct stages: light-emitting element formation on a dedicated semiconductor substrate, drive circuit formation on a separate substrate, and subsequent transfer. This segmentation simplifies each individual process, reducing the cumulative risk of connection defects while maintaining precise alignment capabilities during the transfer stage.
Solution Approach 2:
The invention introduces a transfer substrate as an intermediary between the semiconductor substrate containing light-emitting elements and the drive circuit substrate. This intermediary facilitates controlled transfer and alignment, reducing direct handling complexity and minimizing connection defects while preserving manufacturing precision.
3Measurement precision
If many micro LEDs are individually formed and sequentially transferred for high-definition displays, then image quality improves, but the enormous amount of time required for transfer increases production cost
Solution Approach 1:
The invention performs preliminary batch formation of multiple light-emitting elements on a semiconductor substrate before transfer. This preliminary action enables parallel processing of numerous light-emitting elements, dramatically reducing the total transfer time required for high-definition displays while maintaining the precise positioning needed for high image quality.
Solution Approach 2:
The invention merges multiple light-emitting element formations into a single batch process on a semiconductor substrate. By combining what would otherwise be numerous sequential operations into one parallel process, the invention reduces total production time while maintaining the high definition quality required for 4K and 8K displays.
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 shortens the transfer process, increases yield, and allows for higher definition and lower production costs by directly forming and connecting light-emitting elements on a drive circuit substrate, improving luminous efficiency and reducing the complexity of micro LED placement.
Implementation Method 1
a semiconductor layer including a light-emitting layer is grown on a Si substrate
Implementation Method 2
a light-emitting element that includes a light-emitting surface on the first part and a top surface at a side opposite to the light-emitting surface
Implementation Method 3
The first via is located between the first wiring layer and the second wiring layer and electrically connects the first wiring layer and the second wiring layer
Data Source
AI summary
A method for manufacturing an image display device according to an embodiment includes: preparing a first substrate, the first substrate including a circuit element, a first wiring layer connected to the circuit element, and a first insulating film covering the circuit element and the first wiring layer; forming a conductive layer including a single-crystal metal on the first insulating film; forming a semiconductor layer including a light-emitting layer on the single-crystal metal; forming a light-emitting element including a light-emitting surface by patterning the semiconductor layer; forming a second insulating film covering the first insulating film, the conductive layer, and the light-emitting element; forming a first via extending through the first and second insulating films; forming a second wiring layer on the second insulating film; and removing at least a portion of the conductive layer on the light-emitting surface.