Hard Coating Layer for Flexible Display
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flexible display devices face challenges in achieving both high hardness and stretchability due to delamination issues between the window layer and hard coating layer, limiting their ability to maintain functionality during stretching.
Innovation Solution
A flexible display device is designed with a hard coating layer that includes an elastic layer and a plurality of fillers, such as silicon-based or nano-silica-based materials, arranged in specific shapes and orientations, which provides increased hardness and elasticity, allowing for both protection and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a hard coating layer is applied on a window layer to increase hardness, then the window surface hardness is improved, but the stretchability is reduced and delamination occurs
Solution Approach 1:
The patent applies composite materials by combining an elastic polymer matrix with inorganic filler particles to create a hard coating layer that exhibits both hardness and elasticity. The composite structure allows the coating to maintain structural integrity during stretching while providing the required surface hardness, thereby resolving the contradiction between hardness and stretchability.
Solution Approach 2:
The patent changes the physical and chemical parameters of the coating layer by selecting specific polymer materials with appropriate elastic moduli and incorporating fillers with controlled size, shape, and distribution. These parameter adjustments enable the coating to achieve optimal balance between hardness and stretchability, preventing delamination while maintaining surface hardness.
2Reliability
If a hard coating layer is applied to protect the window layer, then protection is improved, but the flexibility and elongation are reduced
Solution Approach 1:
The patent employs flexible thin film technology by using a polymer-based coating layer that can bend and stretch with the underlying window layer. The thin film structure provides protection while maintaining flexibility, allowing the display device to be folded or bent without compromising either protection or flexibility.
Solution Approach 2:
The composite material system combines the protective function of inorganic fillers with the flexibility of the polymer matrix, creating a coating that simultaneously delivers protection and flexibility. The synergistic interaction between the matrix and filler components enables the coating to deform elastically under stress while maintaining its protective barrier properties.
3Strength
If a hard coating layer is applied to increase surface hardness, then hardness is improved, but delamination between layers occurs during stretching
Solution Approach 1:
The patent optimizes adhesion parameters by selecting polymer materials with appropriate surface energy and molecular weight, and by controlling the size, surface treatment, and distribution of filler particles. These parameter changes enhance the interfacial bonding between the coating layer and window layer, preventing delamination during stretching while maintaining surface hardness.
Solution Approach 2:
The polymer matrix acts as an intermediary between the inorganic filler particles and the window layer, providing strong adhesion to both. The matrix material creates a transition zone that accommodates stress during stretching, preventing direct stress concentration at the coating-substrate interface and thereby preventing delamination.
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 the flexible display device to simultaneously satisfy hardness and elongation requirements, minimizing image distortion during stretching and enhancing resistance to pressure and puncture by evenly dispersing stress and improving the elastic restoring force of the hard coating layer.
Implementation Method 1
the hard coating layer includes an elastic layer and a plurality of fillers included in the elastic layer
Implementation Method 2
a hard coating layer that includes an elastic layer and a plurality of fillers, such as silicon-based or nano-silica-based materials
Implementation Method 3
the hard coating layer includes an elastic layer and a plurality of fillers included in the elastic layer
Implementation Method 4
a plurality of fillers, such as silicon-based or nano-silica-based materials, arranged in specific shapes and orientations, which provides increased hardness and elasticity
Implementation Method 5
evenly dispersing stress and improving the elastic restoring force of the hard coating layer
Implementation Method 6
improving the elastic restoring force of the hard coating layer
Data Source
AI summary
A flexible display device is disclosed. In one aspect, the display device includes a display substrate and a display element layer formed over the display substrate and including a matrix of pixels. The display device also includes a thin film encapsulation layer formed over the display substrate and the display element layer so as to protect the display substrate and the display element layer. The display device further includes a window layer formed over the thin film encapsulation layer and a hard coating layer formed over the window layer and having greater hardness than the window layer. The hard coating layer comprises an elastic layer including a plurality of fillers.