Flexible Display Encapsulation with Anisotropic Moisture Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rigid displays are difficult to integrate into devices with bendable housings, and flexible displays face challenges in maintaining encapsulation layer integrity when flexed, leading to potential damage from bending-induced stress.
Innovation Solution
A flexible display with a flexible substrate, thin-film transistor layer, and organic light-emitting diodes is encapsulated using a flexible encapsulation layer with an anisotropic moisture diffusion characteristic, coated with an inorganic conformal pinhole filling layer and a moisture barrier, and protected by a polymer layer to reduce stress and prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If rigid planar substrates are used for displays, then display structural integrity is maintained, but integration into bendable housings becomes difficult
Solution Approach 1:
The patent replaces rigid planar substrates with flexible substrates that can bend and conform to the contours of bendable housings. This allows the display to be integrated into devices with rotating or flexible portions while maintaining structural integrity through the inherent flexibility of the substrate material.
2Adaptability or versatility
If flexible substrates are used to enable bending, then adaptability to bendable housings is improved, but encapsulation layers become vulnerable to damage during flexing
Solution Approach 1:
The patent employs a composite encapsulation structure consisting of multiple layers including inorganic barrier layers and organic flexible layers. This composite structure combines the moisture barrier properties of inorganic materials with the flexibility and stress resistance of organic materials, allowing the encapsulation to protect the display during bending while preventing moisture ingress.
Solution Approach 2:
The patent introduces a multi-layer encapsulation architecture that adds dimensional complexity to the protection system. By stacking multiple encapsulation layers with different material properties and orientations, the system distributes bending stresses across multiple interfaces and prevents crack propagation that would occur in single-layer encapsulation.
3Object-affected harmful factors
If inorganic encapsulation layers are placed close to the display components for better protection, then moisture barrier effectiveness is improved, but bending-induced cracks increase
Solution Approach 1:
The patent places flexible organic buffer layers between the rigid inorganic encapsulation layers and the display components. These buffer layers absorb and distribute bending stresses before they reach the inorganic layers, preventing crack formation while allowing the inorganic layers to maintain their moisture barrier function.
Solution Approach 2:
The patent creates a non-uniform encapsulation structure where different layers are positioned at different distances from the display components based on their specific functions. Inorganic barrier layers are placed where moisture protection is most critical, while flexible buffer layers are positioned where stress absorption is needed, optimizing both protection and flexibility locally.
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 enables flexible displays that can bend without damaging the encapsulation layer, reducing moisture penetration and bending-induced cracks, thus enhancing the durability and reliability of flexible electronic devices.
Implementation Method 1
The flexible encapsulation layer may include a lateral dispersion layer that exhibits an anisotropic moisture diffusion characteristic. Lateral diffusion in the lateral dispersion layer is larger than vertical dispersion in a direction that runs perpendicular to the display.
Implementation Method 2
The pinhole filling layer may be deposited using atomic layer deposition. By coating and smoothing particles on the lateral diffusion (dispersion) layer, the particles will not damage the encapsulation layer.
Data Source
AI summary
A flexible display encapsulation layer may be used to encapsulate and protect organic light-emitting diodes and a thin-film transistor layer on a flexible display. The flexible encapsulation layer may include a lateral dispersion layer that exhibits an anisotropic moisture diffusion characteristic. Lateral diffusion in the lateral dispersion layer is larger than vertical dispersion in a direction that runs perpendicular to the display. An inorganic conformal coating layer may cover the lateral diffusion layer and may serve as a pinhole filling layer. The pinhole filling layer may be covered with a moisture barrier layer that serves to prevent moisture from penetrating the display. A polymer protective layer may cover the moisture barrier layer and may be relatively insensitive to bending induced stress as the display is flexed.