Foldable Window Groove Patterns for Impact Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing flexible display devices with foldable or bendable windows are prone to deformation and damage due to folding or external impacts, which affects their reliability and mechanical properties.

Innovation Solution

A window design featuring a substrate with a folding area and non-folding areas, incorporating groove patterns along a direction crossing the folding axis. These groove patterns have a bottom surface recessed from the upper surface and a side surface with at least one curved surface, improving folding and impact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the window is made flexible to enable folding, then the portability and adaptability of the display device are improved, but the window becomes prone to deformation and damage from external impacts

Engineering Contradiction:

Improvefolding capabilityVSAvoidresistance to deformation and damage

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The window is segmented into multiple groove patterns arranged in the folding area, creating discrete structural units that can independently manage stress during folding. Each groove pattern acts as an independent element that contributes to the overall flexibility while maintaining structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The side surfaces of the groove patterns include curved surfaces that allow progressive deformation during folding. The curvature enables the material to bend smoothly along the folding axis, distributing stress evenly and preventing sudden failure or deformation.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Ease of manufacture

If the window structure is simplified to ease manufacturing, then the manufacturing cost and complexity are reduced, but the folding properties and impact resistance are compromised

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidfolding and mechanical properties

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The groove patterns are formed by controlling laser beam parameters (power, speed, pulse duration) and etching parameters (solution concentration, temperature, time) to achieve the desired groove depth, width, and curvature. By optimizing these parameters, complex three-dimensional groove structures are created through relatively simple manufacturing steps.

Inventive Principle:

Principle #35Parameter changes

3Strength

If the groove patterns are made deeper to improve impact resistance, then the mechanical strength is enhanced, but the folding flexibility is reduced

Engineering Contradiction:

Improveimpact resistanceVSAvoidfolding flexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The curved side surfaces of the grooves allow the material to deform progressively during folding, accommodating deeper grooves without compromising flexibility. The curvature creates a gradual transition that distributes bending stress, enabling the structure to maintain both depth for strength and curvature for flexibility.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The groove depth and curvature are optimized in the specific folding area where flexibility is needed, while maintaining adequate thickness in non-folding areas for impact resistance. This localized optimization allows different regions of the window to have different mechanical properties suited to their functional requirements.

Inventive Principle:

Principle #3Local quality

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 window exhibits enhanced folding properties and impact resistance, preventing damage from repeated folding and external impacts, thereby improving the reliability of the display device.

Implementation Method 1

irradiating a first laser beam onto first portions overlapping the first line toward a thickness direction of the mother substrate... the first portions irradiated with the first laser beam have a thickness smaller than a thickness of the mother substrate

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

providing an alkaline solution onto the first portions to etch the first portions

Methodology Applied

Scientific EffectChemical etching:

Data Source

PatentUS12265425B2Foldable window, display device including the same, and a method of manufacturing the window

Publication Date: 2025.04.01 SAMSUNG DISPLAY CO LTD

AI summary

A window includes a substrate including a folding area folded about an imaginary folding axis and a non-folding area and including an upper surface and a lower surface and a plurality of groove patterns arranged in the folding area along a first direction crossing the folding axis. Each of the groove patterns includes a bottom surface recessed from the upper surface and substantially parallel to the upper surface and a side surface connecting the bottom surface and the upper surface. The side surface includes at least one curved surface.