Gradient Elasticity Encapsulation for OLED Interfacial Peeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting elements are prone to degradation due to external moisture and oxygen, leading to interfacial peeling in encapsulation films, which can cause failure in display and lighting devices.
Innovation Solution
A device with light emitting elements is designed, featuring a substrate with emission and non-emission areas, a first organic film with a low modulus of elasticity, a second organic film with a higher modulus, and a metal film, where the second organic film is placed between the first organic film and the metal film to reduce stress and prevent peeling, and is formed in patterns to block moisture paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an encapsulation film with multiple layers is provided to enhance barrier performance, then moisture and oxygen barrier performance is improved, but the likelihood of interfacial peeling between layers increases
Solution Approach 1:
An intermediate layer is introduced between the first organic film and the metal film to act as a stress buffer. This intermediate layer has a modulus of elasticity greater than the first organic film but less than the metal film, creating a gradual transition in mechanical properties that reduces interfacial stress and prevents peeling while maintaining the multi-layer barrier structure's moisture and oxygen protection capabilities
Solution Approach 2:
The modulus of elasticity parameter is strategically selected for each layer to create a gradient structure. By controlling the mechanical properties (modulus of elasticity) of each layer, the patent optimizes both the barrier performance and interfacial adhesion, preventing peeling while maintaining effective moisture and oxygen blockage
2Reliability
If the modulus of elasticity difference between adjacent layers is large, then barrier performance is enhanced, but stress at interfaces increases causing peeling
Solution Approach 1:
The patent applies parameter change by selecting specific modulus of elasticity values for each layer. The intermediate layer's modulus is deliberately positioned between that of the first organic film and the metal film, creating a gradual parameter transition that reduces stress concentration at interfaces while preserving the barrier function of each layer
3Strength
If a second organic film is added between the first organic film and metal film, then interfacial peeling is prevented, but device structure becomes more complex
Solution Approach 1:
The second organic film serves as an intermediary layer that mediates between the first organic film and the metal film. This intermediate structure prevents direct contact between materials with vastly different mechanical properties, reducing interfacial stress and preventing peeling, while the overall structure remains integrated and functional
Data Source
AI summary
A device with light emitting elements can prevent interfacial peeling of a plurality of layers. The device with light emitting elements includes: a substrate including an emission area in which the light emitting elements are arranged and a non-emission area that surrounds the emission area; a first organic film that covers the emission area and has a first modulus of elasticity; a second organic film that is disposed on the first organic film and has a second modulus of elasticity which is greater than the first modulus of elasticity; and a metal film that is disposed on the second organic film and has a third modulus of elasticity which is greater than the second modulus of elasticity.