Micro-LED Cathode Terminal Layout for Low Voltage Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In micro LED displays, a voltage drop occurs due to the resistance of transparent conductive materials used in the cathode terminals, leading to lower voltage application at micro-LEDs farther from the power wiring line.
Innovation Solution
The cathode terminals are formed of a metal material, such as titanium, instead of transparent conductive materials, and are designed to provide a common power wiring line for each pixel, reducing resistance and voltage drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If transparent conductive materials are used for cathode terminals, then light extraction efficiency is improved, but voltage drop increases due to resistance
Solution Approach 1:
The cathode terminal is divided into multiple segments: a transparent conductive layer for light extraction and a separate metal material layer for low-resistance electrical connection. This segmentation allows each layer to optimize its specific function without compromise.
Solution Approach 2:
The cathode terminal uses a composite structure combining transparent conductive material and metal material. The transparent conductive material layer provides light extraction functionality while the metal material layer provides low-resistance electrical connection, resolving the contradiction between optical and electrical performance.
2Ease of manufacture
If cathode terminals are formed continuously over multiple pixels, then manufacturing is simplified, but voltage drop increases for micro-LEDs farther from power wiring line
Solution Approach 1:
The continuous cathode terminal structure is segmented into discrete cathode terminals for each pixel or pixel group. Each cathode terminal is independently connected to the power wiring line, ensuring uniform voltage distribution across all micro-LEDs while maintaining manufacturing feasibility through standardized processes.
Solution Approach 2:
The cathode terminal structure is optimized locally for each pixel or pixel group, with each having its own dedicated cathode terminal and power connection. This local optimization ensures that voltage drop is minimized for each individual micro-LED without requiring complex global routing.
3Loss of energy
If metal material is used for cathode terminals, then voltage drop is reduced, but light extraction efficiency may be affected
Solution Approach 1:
The cathode terminal is segmented into functionally distinct layers: a transparent conductive material layer that provides light extraction functionality and a metal material layer that provides low-resistance electrical connection. This segmentation allows the metal layer to reduce voltage drop while the transparent layer maintains light extraction efficiency.
Solution Approach 2:
The cathode terminal employs a composite structure where the transparent conductive material layer is combined with a metal material layer. The transparent layer preserves optical properties for light extraction while the metal layer provides superior electrical conductivity, simultaneously addressing both requirements.
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 configuration suppresses voltage drops across micro-LEDs, ensuring consistent voltage application and improving light extraction efficiency by optimizing the layout of cathode terminals.
Implementation Method 1
a voltage drop may occur based on the resistance of the transparent conductive material, and the voltage applied to the cathode terminal may be lower
Data Source
AI summary
According to one embodiment, a display device includes a substrate, a light-emitting element mounted on the substrate, an anode terminal disposed on an bottom portion of the light-emitting element and a cathode terminal disposed on an emitting surface of the light emitting element, on an opposite side to the anode terminal, and the cathode terminal is formed of a metal material.