Flexible Display Crack Suppression via Edge Buffering

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Solution Overview

Problem

Conventional flexible display cutting processes often result in cracks and panel contraction, leading to failure of the thin film encapsulation layer during the separation of individual displays from a flexible mother board.

Innovation Solution

A flexible display design incorporating a crack suppressing layer made of organic material, disposed along the edge of the flexible substrate, which contacts the inorganic layer and thin film encapsulation layer, minimizing crack generation and spread by acting as a buffering member during the cutting process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a press cutting method is used to separate individual displays from the flexible mother board, then the cutting process can be efficiently performed, but cracks are generated in the inorganic layer and thin film encapsulation layer due to strong press cutting force and bending force

Engineering Contradiction:
Improvecutting efficiencyVSAvoidencapsulation layer integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces a release layer between the inorganic layer and the flexible substrate before the cutting process. This release layer is designed to be separated along a predetermined line during cutting, which prevents cracks from propagating into the thin film encapsulation layer. The release layer is prepared in advance and positioned strategically to intercept and stop crack propagation paths.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The release layer acts as an intermediary element between the inorganic layer and the flexible substrate. During the press cutting process, this intermediate layer absorbs and dissipates the mechanical stress and bending forces, preventing direct transmission of cracks to the thin film encapsulation layer while still allowing efficient cutting to occur.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the inorganic layer is positioned close to the edge of the flexible substrate for efficient manufacturing, then manufacturing precision is improved, but crack propagation to the thin film encapsulation layer occurs more easily during cutting

Engineering Contradiction:
Improvelayer positioning precisionVSAvoidcrack propagation
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the structure by introducing a release layer that creates a predetermined separation line. This segmentation allows the inorganic layer to be positioned close to the substrate edge for manufacturing efficiency while the release layer acts as a crack stopper, dividing the potential crack propagation path and preventing cracks from reaching the thin film encapsulation layer.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The release layer is extracted as a separate functional element between the inorganic layer and the flexible substrate. This extracted layer specifically addresses the crack propagation issue without interfering with the manufacturing precision benefits of having the inorganic layer positioned close to the substrate edge.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Prevents the loss of encapsulation function and display failure by reducing crack propagation to the thin film encapsulation layer, thereby maintaining panel integrity and functionality.

Implementation Method 1

The crack suppressing layer may include an organic material... configured to contact the edge of the flexible substrate... minimize a generation of cracks during a cutting process

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The crack suppressing layer may include a UV curable resin and/or a thermosetting resin

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentEP2838132B1Flexible display and method of manufacturing a flexible display
Publication Date: 2023.12.27 SAMSUNG DISPLAY CO LTD
  • EP2838132B1 patent drawingFigure 1
  • EP2838132B1 patent drawingFigure 2
  • EP2838132B1 patent drawingFigure 3

AI summary

A flexible display (100, 200, 300, 400) may suppress a generation of cracks in an inorganic layer (19) and suppress the spread of cracks. A flexible display (100, 200, 300, 400) includes a flexible substrate (10) and an inorganic layer (19) formed on the flexible substrate (10). A display unit (20) is formed on the inorganic layer (19). The display unit (20) includes a plurality of pixels (PE). Each pixel (PE) includes an organic light emitting diode (40). A thin film encapsulation layer (30) covers the display unit (20). A crack suppressing layer (70) is formed along the edge of the flexible substrate (10). The crack suppressing layer (70) is disposed on the inorganic layer (19) at the exterior side of the thin film encapsulation layer (30). A method of manufacturing a flexible display is also disclosed.