Foldable Glass Substrate Structure for Small Bend Radius
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing foldable displays and protective covers face challenges in achieving both small minimum bend radii and good impact and puncture resistance, with plastic displays lacking in resistance and ultra-thin glass-based sheets being prone to mechanical failures.
Innovation Solution
The development of foldable substrates comprising glass-based and/or ceramic-based materials with compressive stress regions, featuring a central portion with reduced thickness and recessed surfaces, which enhances impact and puncture resistance while allowing for small bend radii.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If plastic displays are used to achieve small minimum bend radii, then the bend radius is reduced, but impact and puncture resistance deteriorate
Solution Approach 1:
The patent employs a composite structure consisting of a glass-based substrate (providing strength and rigidity) combined with a plastic layer (providing flexibility and enabling small bend radii). This composite approach allows the display to achieve both small minimum bend radii and good impact/puncture resistance by leveraging the complementary properties of different materials.
2Shape
If ultra-thin glass-based sheets are used to achieve small minimum bend radii, then the bend radius is reduced, but impact and puncture resistance deteriorate
Solution Approach 1:
The patent applies local quality by creating a non-uniform thickness distribution in the glass-based substrate, with a first central surface area recessed from the first major surface. This localized thinning in the central region allows for smaller bend radii while the thicker peripheral regions maintain impact and puncture resistance.
3Strength
If thicker glass-based sheets are used to improve impact and puncture resistance, then strength is improved, but minimum bend radius increases
Solution Approach 1:
The patent resolves this contradiction by implementing local quality through a recessed central portion. The glass-based substrate has reduced thickness in the central area (enabling small bend radii) while maintaining greater thickness at the edges (providing impact and puncture resistance). This localized variation in thickness allows simultaneous optimization of both bending flexibility and mechanical strength.
4Shape
If a recessed central portion is created to reduce thickness and enable small bend radii, then minimum bend radius is reduced, but structural complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the glass-based substrate into distinct regions: a first portion with greater thickness providing structural support, and a second central portion with reduced thickness enabling flexible bending. This segmentation allows the substrate to achieve small minimum bend radii while maintaining structural integrity through the thicker peripheral regions.
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 proposed solution provides foldable substrates with improved mechanical stability, reduced mechanical instabilities, and enhanced impact and puncture resistance, enabling small parallel plate distances and invisible transition regions.
Implementation Method 1
a first polymer-based portion positioned in the first recess
Implementation Method 2
The first portion and/or the second portion can comprise glass-based and/or ceramic-based portions comprising one or more compressive stress regions, which can further provide increased impact resistance and/or increased puncture resistance
Data Source
AI summary
Foldable substrates have a first portion, a second portion, and a central portion positioned therebetween with a first transition region having a first central surface area of the central portion with a first average angle. In aspects, the first average angle is from about 176.10 to about 179.9° or from about 177.0° to about 179.9°. In aspects, a polymer angle is from 178.3° to about 179.9° or from about 179.10 to about 179.9°. Methods comprise disposing an etch mask over the first major surface of the foldable substrate before etching the foldable substrate. In aspects, the etch mask comprises a first polymer layer positioned between a first barrier layer and the first major surface. In aspects, the etch mask comprises a plurality of ink-jet printed shapes. Methods of measuring a contrast ratio comprise impinging a transparent apparatus with a collimated beam.