Thin Window Panel Stress Distribution for Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing window panels, particularly in electronic apparatuses, face challenges in achieving both durability and flexibility while maintaining a thin thickness, as they are prone to structural vulnerability and self-destruction defects due to concentrated compressive stress.
Innovation Solution
A window panel with a substrate thickness of less than 100 μm, incorporating first and second ions with different radii to generate compressive stress that reduces with depth, and a depth of compression between 0.15T and 0.3T, along with a depth of layer of 0.5T or greater, to achieve a balanced stress behavior and improved reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the window panel thickness is reduced to less than 100 μm to achieve flexibility and thinness, then the structural vulnerability increases and the panel becomes prone to self-destruction defects
Solution Approach 1:
The patent applies parameter changes by controlling the depth of compression (DOC) to be within 0.15T to 0.3T of the substrate thickness T, and setting the depth of layer (DOL) to 0.5T or greater. This specific parameter range creates an optimized stress distribution that prevents self-destruction while maintaining thinness. The compressive stress depth is adjusted to balance flexibility and structural integrity.
Solution Approach 2:
The patent implements local quality by creating a non-uniform stress distribution within the substrate. The compressive stress is concentrated in specific depth regions (DOC ≤ 0.3T) while the surface compressive stress (SCS) is enhanced (≥100 MPa). This localized stress optimization allows different regions of the thin substrate to serve different functions - surface regions provide impact resistance while deeper regions maintain flexibility.
2Reliability
If ions are introduced to generate compressive stress for improving durability, then the stress concentration may cause self-destruction defects
Solution Approach 1:
The patent resolves this contradiction by precisely controlling stress distribution parameters. The depth of compression is limited to DOC ≤ 0.3T and depth of layer is set to DOL ≥ 0.5T, creating a gradient stress profile that avoids concentration at critical locations. Surface compressive stress is enhanced to ≥100 MPa while maintaining overall stress balance, preventing self-destruction despite high durability reinforcement.
Solution Approach 2:
The patent applies partial action by introducing ions only to specific depth regions rather than uniformly throughout the substrate. The compressive stress is applied partially in the surface and near-surface regions (within DOC depth) while leaving deeper regions with different stress characteristics. This partial ion introduction achieves durability improvement without creating harmful stress concentration throughout the entire substrate.
3Strength
If the depth of compression is increased to enhance surface compressive stress, then the flexibility and foldability of the window panel deteriorate
Solution Approach 1:
The patent optimizes the flexibility-strength trade-off by setting the depth of compression parameter DOC within 0.15T to 0.3T of the substrate thickness T. This parameter range ensures that compressive stress is sufficient for durability (surface compressive stress ≥100 MPa) while the stress does not extend too deeply to restrict bending and folding capabilities. The specific DOC range acts as an optimization boundary condition.
Solution Approach 2:
The patent implements local quality by concentrating compressive stress in the surface and near-surface regions (within DOC depth from each surface) while maintaining different stress characteristics in the central region. This localized stress distribution allows the surface regions to provide impact resistance and durability, while the central and deeper regions maintain flexibility and enable foldability. The stress profile is spatially differentiated to satisfy conflicting requirements.
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 enhances the durability and reliability of the window panel by distributing compressive stress, reducing the likelihood of self-destruction defects and improving impact resistance while maintaining flexibility and thinness.
Implementation Method 1
first ions dispersed in the substrate and each having a first ion radius, and second ions dispersed in the substrate and each having a second ion radius which is greater than the first ion radius, wherein the second ions generate a predetermined compressive stress
Data Source
AI summary
A window panel includes: a substrate having a thickness of less than 100 μm and including a first surface and a second surface facing each other in a thickness direction; first ions dispersed in the substrate and each having a first ion radius; and second ions dispersed in the substrate and each having a second ion radius which is greater than the first ion radius, wherein the second ions generate a compressive stress, the compressive stress is reduced with depth from the first surface or the second surface within a range from the first surface or the second surface to a ½ point of the thickness.