Micro LED Display Stacked Common Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of micro light emitting diode displays faces challenges with common electrodes made of indium tin oxide, which are not resistant to high temperatures, limiting light transmittance and conductivity improvements.
Innovation Solution
A micro light emitting device display apparatus with a stacked common electrode structure, comprising a first common electrode layer made of metal oxide and a second common electrode layer made of metal or alloy, strategically positioned between micro light emitting devices to enhance conductivity and light transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the film thickness of the common electrode is increased to meet operational conductivity requirements, then the conductivity is improved, but the light transmittance is further reduced
Solution Approach 1:
The common electrode is divided into multiple sub-electrodes (first common electrode, second common electrode, third common electrode) arranged in sequence. This segmentation allows each layer to contribute to conductivity while maintaining overall light transmittance, as no single layer needs to be excessively thick to achieve the required conductivity.
Solution Approach 2:
The patent employs composite material structure with different electrode materials having complementary properties. The first common electrode uses ITO (high transmittance), while the second and third common electrodes use materials like aluminum or silver (high conductivity). This composite approach combines the advantages of different materials to achieve both high conductivity and high light transmittance simultaneously.
2Stability of the object's composition
If indium tin oxide is selected as the common electrode material for high light transmittance and stability, then the stability is improved, but the resistance to high temperature annealing is poor
Solution Approach 1:
The common electrode function is segmented across multiple layers with different materials. The first layer (ITO) provides stability and transmittance, while subsequent layers (aluminum, silver) provide thermal stability and conductivity. This segmentation allows each material to perform its optimal function without being limited by the weaknesses of individual materials.
Solution Approach 2:
The patent introduces intermediate layers and buffer structures between the ITO layer and the micro-LEDs. These intermediate structures protect the ITO from direct high-temperature exposure during annealing processes while still allowing the common electrode to achieve the necessary conductivity through the multi-layer configuration.
Data Source
AI summary
A micro light emitting device display apparatus including a circuit substrate, a plurality of micro light emitting devices, a first common electrode layer, and a second common electrode layer is provided. The micro light emitting devices are disposed on the circuit substrate and individually include an epitaxial structure and a first-type electrode and a second-type electrode respectively disposed on two side surfaces of the epitaxial structure opposite to each other. The first common electrode layer is disposed on the circuit substrate and directly covers the plurality of first-type electrodes of the micro light emitting devices. The second common electrode layer is disposed between the micro light emitting devices. The first common electrode layer is electrically connected to the second common electrode layer.