Flexible Display Wire Insulation Curvature

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Flexible displays face mechanical strain issues during manufacturing and use, particularly at bent portions, leading to cracks and fractures in wires and insulating layers, which can propagate and cause poor electrical contact, rendering the display unusable.

Innovation Solution

A flexible OLED display configuration featuring a flexible substrate with wires and insulating layers that are patterned to reduce mechanical stress, with the upper and lower insulating layers matching the trace pattern of the wires, thereby minimizing crack propagation and enhancing flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the flexible display is bent to a small radius of curvature during manufacturing or use, then the flexibility and design freedom are improved, but mechanical strain causes cracks and fractures in wires and insulating layers

Engineering Contradiction:
ImproveflexibilityVSAvoidwire integrity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The insulating layers are formed with a curved configuration that matches the bending radius of the flexible display. This curvature design allows the insulating layers to naturally follow the bent shape without experiencing excessive tensile or compressive stress, thereby preventing cracks and fractures while maintaining electrical connectivity during flexing operations

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent modifies the geometric parameters of the insulating layers by forming them with specific curvature radii that correspond to the bending radius of the flexible display. This parameter adjustment optimizes the stress distribution within the insulating layers during bending, reducing mechanical strain and preventing structural failure of the wire connections

Inventive Principle:
Principle #35Parameter changes

2Reliability

If additional layers are added to protect wires during bending, then wire protection is improved, but the display thickness increases and bending to small radius becomes difficult

Engineering Contradiction:
Improvewire protectionVSAvoiddisplay thickness
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The insulating layers are applied selectively only in regions where wires are present and where bending stress is concentrated. This localized insulation approach provides targeted protection to the wire connections without adding unnecessary thickness to the entire display structure, maintaining both wire integrity and flexibility

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of adding protective layers in the thickness dimension, the patent employs curvature in the spatial arrangement of the insulating layers. By forming these layers with a bent configuration matching the display's bending radius, protection is achieved through geometric adaptation rather than increased material thickness

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Strength

If wires are made larger or more ductile to withstand strain, then wire strength is improved, but the display becomes thicker and less flexible

Engineering Contradiction:
Improvewire strengthVSAvoidflexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The insulating layers are pre-formed with a curved configuration that anticipates the bending stress the wires will experience during flexing. This preliminary geometric preparation allows the wire-insulating layer assembly to flex smoothly without requiring the wires themselves to be made larger or more ductile, preserving both strength and flexibility

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2956923B1Electronic devices with flexible display
Publication Date: 2021.06.09 LG DISPLAY CO LTD
  • EP2956923B1 patent drawingFigure 1a~1c
  • EP2956923B1 patent drawingFigure 1d~1e
  • EP2956923B1 patent drawingFigure 2~3

AI summary

There is provided a flexible display having a new wire structure and a new insulating layer structure. A flexible display includes a flexible substrate having a first area and a second area. The second area is curved in a non-zero angle relative to the plane of the first area. The flexible display further includes a plurality of wires that extend over from the first area to the second area of the flexible substrate. Each of the wires is covered by an upper insulating pattern, which is separated from other upper insulating pattern. Each upper insulating pattern covering the wire has substantially the same trace pattern shape of the corresponding wire thereunder. Accordingly, by adopting the above-described wire structure and upper insulating layer structure, cracks generation and propagation in the wires and the insulating layers from bending of the flexible display can be minimized.