Tiled Display Substrate Assembly for Hidden Bezels and Pad Isolation

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Solution Overview

Problem

Large-sized display devices face increased defect rates and productivity issues due to the number of pixels, leading to reliability concerns and a sense of disconnection between tiled display units, as well as visibility of boundary portions in tiled display devices.

Innovation Solution

A display device design featuring a first substrate with a laser absorption layer, barrier insulating layers, fan-out lines, and a second substrate inserted into contact holes, with an etched portion to prevent peeling and insulate adjacent pad portions, minimizing non-display areas and enhancing image immersion by reducing visible boundaries between units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the display device is manufactured in a large size, then the screen area is increased, but the defect rate of light emitting elements increases due to the increase in the number of pixels

Engineering Contradiction:

Improvescreen areaVSAvoiddefect rate

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The display device is divided into multiple small-sized display units that are connected to form a large-sized display. Each display unit contains a manageable number of pixels, maintaining low defect rates while collectively providing a large screen area. The segmentation is achieved through separate substrates for each display unit that are bonded together.

Inventive Principle:

Principle #1Segmentation

2Area of stationary object

If multiple display devices are connected to form a tiled display, then the screen area is increased, but boundary portions and non-display areas become visible reducing immersion

Engineering Contradiction:

Improvescreen areaVSAvoidsense of disconnection

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

Multiple display units are bonded together with their non-display areas facing each other to create a seamless tiled display. The bonding structure merges the adjacent display units such that the boundary portions and non-display areas become hidden or imperceptible, providing a continuous visual experience across the entire large screen.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If the second substrate is not properly secured, then the manufacturing process is simpler, but the second substrate may peel off during etching process

Engineering Contradiction:

Improvesubstrate assemblyVSAvoidsubstrate bonding

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The second substrate is preliminarily secured to the first substrate through contact holes formed in the laser absorption layer and barrier insulating layers before the etching process. This preliminary bonding action prevents the second substrate from peeling off during subsequent etching operations, ensuring reliable substrate assembly while maintaining manufacturing feasibility.

Inventive Principle:

Principle #10Preliminary action

4Device complexity

If adjacent pad portions are not insulated, then the structure is simpler, but adjacent pad portions may be electrically connected causing defects

Engineering Contradiction:

Improveinsulation structureVSAvoidelectrical isolation

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The laser absorption layer and barrier insulating layers serve as intermediary structures between adjacent pad portions. These intermediate layers provide electrical isolation to prevent unwanted electrical connections between adjacent pad portions, ensuring reliable electrical insulation while maintaining a manageable device structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 prevents substrate peeling and insulates adjacent pad portions, reducing defect rates and improving image immersion by minimizing visible boundaries in tiled display devices.

Implementation Method 1

a laser absorption layer disposed on the first substrate and containing amorphous silicon

Methodology Applied

Scientific EffectLaser absorption: Absorption (EM radiation)

Data Source

PatentUS20240105897A1Display device, method of manufacturing the same and tiled display device including the same

Publication Date: 2024.03.28 SAMSUNG DISPLAY CO LTD

AI summary

A display device comprises a first substrate comprising a first contact hole, a laser absorption layer disposed on the first substrate and containing amorphous silicon, a first barrier insulating layer disposed on the laser absorption layer, fan-out lines disposed in a metal layer on the first barrier insulating layer and comprising pad portions inserted into second contact holes provided in the first barrier insulating layer and the laser absorption layer, a second barrier insulating layer disposed on the metal layer, a second substrate disposed on the second barrier insulating layer, and a display layer disposed on the second substrate. The second substrate is inserted into a third contact hole provided in the second barrier insulating layer, the first barrier insulating layer, and the laser absorption layer disposed between the pad portions.