Cover Window with Local Thickness Variation for Foldable Displays
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Solution Overview
Problem
Existing cover windows for foldable display devices face challenges in achieving a balance between mechanical strength and flexibility, as they tend to be either too thick for strength or too thin for durability, and current manufacturing methods are inefficient in creating thin, recessed structures that can withstand folding stress.
Innovation Solution
A method of fabricating a cover window involving a glass article with a mask layer having recessed and flat portions, where the mask layer is etched using a wet etching process to create a partially recessed upper surface, resulting in a cover window with a slimming portion and non-slimming portions of varying thicknesses, allowing for flexibility and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the cover window is made thinner to reduce bending stress and improve flexibility, then the flexibility for folding is improved, but the mechanical strength and durability against external impacts deteriorate
Solution Approach 1:
The cover window is designed with non-uniform thickness: a first region with greater thickness for mechanical strength and durability, and a second region with smaller thickness for flexibility during folding. This local variation in thickness allows different parts of the cover window to serve different functional requirements simultaneously.
2Ease of manufacture
If the cover window has uniform thickness to maintain simplicity in manufacturing, then the ease of manufacture is improved, but the ability to reduce bending stress at folding regions deteriorates
Solution Approach 1:
The cover window is designed with non-uniform thickness: a first region with greater thickness for mechanical strength and durability, and a second region with smaller thickness for flexibility during folding. This local variation in thickness allows different parts of the cover window to serve different functional requirements simultaneously.
3Reliability
If the cover window is made thicker to improve durability against external impacts, then the mechanical strength is improved, but the flexibility for folding and user convenience deteriorates
Solution Approach 1:
The cover window is designed with non-uniform thickness: a first region with greater thickness for mechanical strength and durability, and a second region with smaller thickness for flexibility during folding. This local variation in thickness allows different parts of the cover window to serve different functional requirements simultaneously.
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 fabricated cover window achieves a balance between flexibility for folding and durability against external impacts, with the slimming portion reducing compressive stress and the non-slimming portions providing mechanical strength, while the etching process simplifies manufacturing and minimizes visibility of boundaries.
Implementation Method 1
The forming of the cover window is performed by a wet etching process. In the forming of the cover window, the mask layer is dissolved by an etchant and the upper surface of the glass article is partially etched.
Data Source
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AI summary
In a method of fabricating a cover window, the method includes: forming, on a glass article having a flat upper surface, a mask layer including water glass and a recess portion having a partially recessed upper surface; and etching the mask layer and the glass article to form a cover window having a partially recessed upper surface.