Micro LED Optical Interconnect Layout for Light Extraction Reliability
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Solution Overview
Problem
Existing optical interconnect systems using micro LEDs face challenges in improving light extraction efficiency and reliability.
Innovation Solution
An optical interconnect system is designed with a micro LED array, a photodiode array, and an optical transmission medium, featuring a layered structure that includes a conductive base semiconductor layer, a semiconductor light-emitting structure, and a passivation layer, along with a reflective structure and electrode layers, to enhance light extraction and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a micro LED structure is used for optical interconnect, then device size is reduced, but light extraction efficiency deteriorates
Solution Approach 1:
The patent applies curvature by forming a convex curved surface on the lower surface of the micro LED chip using reflow processing. This curved surface increases the extraction efficiency of downward-directed light by reducing total internal reflection at the semiconductor-substrate interface, thereby improving light extraction efficiency while maintaining the reduced device size of micro LEDs.
Solution Approach 2:
The patent applies local quality by selectively forming a reflective film on specific regions of the lower surface of the micro LED chip. The reflective film is deposited on the convex curved surface and extends to flat regions, creating zones with different optical properties. This localized modification optimizes light extraction in specific areas while maintaining the compact micro LED structure.
2Loss of energy
If multiple layers are stacked in micro LED to improve light extraction, then light extraction efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by designing the lower surface structure to serve multiple purposes: the convex curved surface both extracts downward light and provides a platform for reflective film deposition, while the reflective film simultaneously reflects light and protects the semiconductor structure. This integrated design improves light extraction efficiency without proportionally increasing device complexity.
Solution Approach 2:
The patent applies preliminary action by pre-forming the convex curved surface through reflow processing before depositing the reflective film. This sequence allows the curved surface geometry to be established first, optimizing light extraction paths, and then the reflective film is added to enhance reflection without requiring complex simultaneous structuring, thereby managing device complexity.
3Loss of energy
If reflective structure is added to micro LED, then light extraction efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies merging by combining the convex curved surface formation and reflective film deposition into an integrated manufacturing process. The reflow processing that creates the curved surface is performed in the same manufacturing sequence as the reflective film deposition, merging two functions into a coordinated process flow. This reduces manufacturing complexity compared to separate, independent structuring and coating steps.
Solution Approach 2:
The patent applies self-service by using the reflow processing step to automatically form the convex curved surface geometry without requiring additional dedicated structuring equipment or processes. The existing reflow step, necessary for other manufacturing reasons, is utilized to create the light-extraction-enhancing curved surface, thereby improving light extraction efficiency without proportionally increasing 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 system improves light extraction efficiency and reliability by optimizing the layered structure and manufacturing process, ensuring effective signal transmission and increased intensity.
Implementation Method 1
Light-emitting diodes (LEDs) may refer to light sources that may convert an electrical energy into an optical energy
Implementation Method 2
a photodiode array on a side of the micro LED array and including at least one photodiode
Implementation Method 3
an optical transmission medium coupled with the micro LED array and the photodiode array and including an optical fiber
Data Source
Figure 1
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AI summary
An optical interconnect system (1) includes a micro light-emitting diode, LED, array (10) including at least one micro LED, a photodiode array (20) on a side of the micro LED array (10) and including at least one photodiode, an optical transmission medium (40) coupled with the micro LED array (10) and the photodiode array (20), and a circuit board (IC) apart from the optical transmission medium in a vertical direction (Z) with the micro LED array (10) and the photodiode array (20) therebetween. The at least one micro LED includes a plurality of layers sequentially stacked in the vertical direction (Z).