OLED Cover Electrode and Sealant Integration for Moisture Barrier
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Solution Overview
Problem
Organic light emitting diode devices face degradation due to moisture and oxygen penetration into the organic emission layer, leading to reduced lifespan and quality, and existing sealing methods are complex and detrimental to productivity.
Innovation Solution
An organic light emitting diode device is constructed with a substrate, a transparent electrode, an organic emission layer, a metal cover electrode with an oxide film, and a sealant made of inorganic particles, where the cover electrode and sealant work together to prevent moisture and oxygen ingress, with the cover electrode being formed from metals like aluminum, silver, or gold and the sealant comprising silicon oxide or zinc oxide particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional sealing structure (glass can or metal can with groove) is used to prevent moisture and oxygen penetration, then the sealing performance is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the sealing function with the cover electrode by forming the cover electrode to extend beyond the emission layer edges and overlap the side surfaces. This integration eliminates the need for separate sealing structures like glass cans or metal cans with grooves, while maintaining effective moisture and oxygen barrier protection through the combined cover electrode-sealant system.
Solution Approach 2:
The cover electrode serves multiple functions: it provides electrical connection as the cathode, acts as a physical barrier against moisture and oxygen, and works with the sealant to seal the emission layer edges. This multi-functionality replaces conventional single-purpose sealing structures, reducing overall device complexity while improving reliability.
2Object-affected harmful factors
If additional sealing structures are added to prevent moisture and oxygen ingress, then the protection against harmful factors is improved, but the manufacturing process becomes more complex and productivity decreases
Solution Approach 1:
The sealing function is merged into the cover electrode formation process. The cover electrode is formed to extend beyond the emission layer, and the sealant is applied to overlap the edges, creating an integrated sealing system that is manufactured in the same process steps as the electrode itself, eliminating separate sealing operations.
Solution Approach 2:
The cover electrode structure is designed to perform both electrical function (cathode) and sealing function simultaneously. This multi-functionality reduces the number of manufacturing steps compared to conventional approaches that require separate sealing structures, thereby improving productivity while maintaining protection against moisture and oxygen.
3Reliability
If the cover electrode thickness is increased to improve moisture and oxygen barrier, then the protection performance is improved, but the material consumption and device complexity increase
Solution Approach 1:
The cover electrode is designed with different thicknesses in different regions: thicker at the edges where it overlaps the emission layer side surfaces to provide enhanced barrier protection, and thinner in the central area where electrical function is primary. This local variation optimizes material usage while maintaining effective sealing performance.
Solution Approach 2:
The sealing system uses a composite structure combining the metal cover electrode with an organic sealant material. The sealant fills gaps and provides additional barrier properties, allowing the use of thinner metal layers while maintaining overall barrier performance, thus reducing total material consumption.
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 solution effectively suppresses moisture and oxygen penetration, enhancing the lifespan and quality of the organic light emitting diode device without the need for additional sealing structures, maintaining luminance ratio above 50% for over 700 hours, while maintaining a simple and efficient manufacturing process.
Implementation Method 1
a cover electrode formed on the organic emission layer and made of a metal... The cover electrode may include an oxide film formed on a first surface of the cover electrode
Implementation Method 2
The organic light emitting diode emits light using energy generated when excitons produced by electron-hole combinations in an organic emission layer drop from an excitation state to a ground state
Implementation Method 3
firstly irradiating a laser beam to the dried sealing mixture to remove the remaining part of the organic binder and the solvent, and secondly irradiating the laser beam to harden the sealing mixture
Data Source
AI summary
An organic light emitting diode device and a manufacturing method thereof. The organic light emitting diode device includes a substrate main body, a transparent electrode formed on the substrate main body, an organic emission layer formed on the transparent electrode, a cover electrode formed on the organic emission layer and made of a metal, and a sealant formed on the substrate main body to overlap an edge of the cover electrode and cover a side surface of the organic emission layer.