Ultra-thin Fin LED Device Self-Alignment and Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current micro-LED and nano-LED technologies face challenges in manufacturing high-resolution displays due to limitations in process technology, high unit prices, high defect rates, and low productivity, particularly in achieving efficient light emission and self-alignment on electrodes, with issues like surface defects and electron-hole recombination inefficiencies.
Innovation Solution
The development of an ultra-thin fin LED device with a structure where the length is longer than the width and thickness, featuring a first and second conductive semiconductor layer stacked in the z-axis direction, and handle electrodes that electrically connect only to specific layers, allowing for self-alignment and reduced surface defects, enhancing light extraction efficiency and luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If nanorod-type LED devices are used with major axis coinciding with stack direction, then the structure is simple, but the emission area is narrow and surface defects have large effect on efficiency degradation
Solution Approach 1:
The patent changes the orientation of the LED device from vertical (major axis along stack direction) to horizontal (major axis perpendicular to stack direction). This dimensional change increases the emission area from the top surface only to include both top and side surfaces, while reducing the impact of surface defects on overall efficiency.
2Area of moving object
If wafer is etched deeply to increase emission area, then more light can be emitted, but surface defects are highly likely to occur
Solution Approach 1:
Instead of increasing emission area through deep vertical etching, the patent reorients the device horizontally so that the emission area is increased by changing the viewing angle rather than digging deeper. This avoids the surface defect problem associated with deep etching.
Solution Approach 2:
The patent inverts the conventional approach by making the side surfaces emit light instead of relying primarily on the top surface. This inversion allows the device to achieve large emission area without deep etching into the wafer.
3Ease of manufacture
If pick and place technology is used for manufacturing, then individual LED placement is possible, but process defect rate is high and productivity is low
Solution Approach 1:
The patent enables LEDs to self-align on the substrate through electric field effects during the dropping process, eliminating the need for complex pick-and-place positioning systems. This self-service alignment mechanism dramatically improves productivity while maintaining placement precision.
Solution Approach 2:
The patent replaces the mechanical pick-and-place system with a simpler dropping method combined with electric field-based self-alignment. This substitution of mechanical positioning with field-based alignment improves both productivity and reduces process defects.
4Reliability
If electron-hole recombination rate is optimized, then luminous efficiency improves, but manufacturing complexity increases
Solution Approach 1:
The patent optimizes the orientation and geometry parameters of the LED device (horizontal placement, major axis perpendicular to stack direction) to naturally improve electron-hole recombination efficiency. This parameter change approach achieves better luminous efficiency without adding manufacturing complexity.
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 ultra-thin fin LED device achieves improved light extraction efficiency, reduced surface defects, and optimized electron-hole recombination, enabling high luminance and efficient self-alignment on electrodes, suitable for high-resolution displays.
Implementation Method 1
an ultra-thin fin LED device which reduces the thickness of a photoactive layer exposed to a surface to prevent a degradation in efficiency due to surface defect while increasing an emission area
Implementation Method 2
a first handle electrode formed to at least partially cover one end surface of the device unit in the x-axis direction and a second handle electrode formed to at least partially cover the other end surface opposite to the one end surface, wherein the first handle electrode is electrically connected only to the first conductive semiconductor layer
Data Source
AI summary
The present invention relates to an LED device, more particularly, to an ultra-thin fin LED device and a method for manufacturing the same.