ESD Circuit Relocation for Flexible Display Moisture Protection

Solution Overview

Problem

Display devices with bent lines in the display panel suffer from cracks and separation in peripheral components, leading to moisture permeation and electrical corrosion of ESD circuits.

Innovation Solution

A display device with a display panel divided into display, non-display, bending, and pad areas, featuring an ESD circuit in the pad area protected by a planarization layer and a passivation layer with trenches to prevent moisture and oxygen penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If lines are bent from front to rear of display panel to reduce bezel, then bezel size is reduced, but cracks and separation occur in peripheral components causing moisture permeation

Engineering Contradiction:

Improvebezel sizeVSAvoidelectrical connection reliability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The ESD circuit is extracted from the bending area and relocated to the pad area, which remains planar during bending. This separation allows the main display panel to be bent for bezel reduction while the ESD circuit resides in a stable, non-bending region, preventing cracks and moisture permeation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A planarization layer is formed over the ESD circuit before bending occurs, creating a protective cushion that prevents cracks and separation in the peripheral components. This layer maintains structural integrity and prevents moisture permeation during the bending process.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If ESD circuit is placed in bending area, then device complexity is reduced, but ESD circuit becomes electrically corroded or oxidized due to moisture permeation

Engineering Contradiction:

Improvecircuit layout complexityVSAvoidmoisture permeation

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The ESD circuit is extracted from the bending area and relocated to the pad area, which remains planar during bending. This separation allows the main display panel to be bent for bezel reduction while the ESD circuit resides in a stable, non-bending region, preventing cracks and moisture permeation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A planarization layer is formed as a protective film over the ESD circuit, providing a barrier against moisture and oxygen permeation. This thin film structure protects the ESD circuit from environmental harmful factors while maintaining the device's overall flexibility in the bending area.

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If planarization layer covers ESD circuit in bending area, then ESD circuit is protected from moisture, but planarization layer comes off during bending

Engineering Contradiction:

ImproveESD circuit protectionVSAvoidplanarization layer adhesion

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The ESD circuit is extracted from the bending area and relocated to the pad area, which remains planar during bending. This separation allows the main display panel to be bent for bezel reduction while the ESD circuit resides in a stable, non-bending region, preventing cracks and moisture permeation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A planarization layer is formed over the ESD circuit before bending occurs, creating a protective cushion that prevents cracks and separation in the peripheral components. This layer maintains structural integrity and prevents moisture permeation during the bending process.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 effectively protects the ESD circuit from external moisture and oxygen, ensuring reliable operation even when the display panel is bent, thereby enhancing the reliability of the display device.

Implementation Method 1

at least one electrostatic discharge (ESD) circuit disposed in the pad area and connected to the at least one gate driver through a discharge line

Methodology Applied

Scientific EffectElectrostatic discharge: Electrostatic Discharge

Implementation Method 2

due to a first trench and a second trench, even when a display panel is bent, a planarization layer configured to cover an electrostatic discharge circuit does not come off, so that external moisture or oxygen cannot penetrate into the electrostatic discharge circuit

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS20250127003A1Display Device

Publication Date: 2025.04.17 LG DISPLAY CO LTD

AI summary

According to an exemplary embodiment of the present disclosure, a display device includes a display panel divided into a display area, a non-display area, a bending area, and a pad area and bent in one direction in the bending area; a plurality of pixels disposed in the display area; at least one gate driver disposed in the non-display area and configured to supply a gate voltage to the plurality of pixels; flexible films connected to a plurality of pads disposed in the pad area; and at least one electrostatic discharge (ESD) circuit disposed in the pad area and connected to the at least one gate driver through a discharge line.