Frame-like Oxide Semiconductor Layer for Laser Processing in Display Devices

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Solution Overview

Problem

The challenge is to remove a common functional layer from a non-display region in an organic EL display device without damaging the functional layer in the display region, particularly due to the difficulty in shielding the non-display region during vapor deposition and the risk of laser-induced damage.

Innovation Solution

A display device configuration that includes a resin substrate with a thin film transistor layer, a light-emitting element layer, and a sealing film, featuring a frame-like oxide semiconductor layer around a through hole in the non-display region. This setup allows for the removal of the common functional layer in the non-display region using laser irradiation without damaging the display region's functional layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a metal layer is provided in the non-display region to convert light to heat for removing the common functional layer, then the common functional layer can be removed by laser irradiation, but the organic EL layer in the display region may be damaged due to stray light of reflected light

Engineering Contradiction:

Improveremoval of common functional layerVSAvoiddamage to organic EL layer from laser stray light

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter from metal to oxide semiconductor, which fundamentally alters the optical properties. The oxide semiconductor has lower reflectivity and different light absorption characteristics compared to metal, reducing the intensity of reflected stray light that could damage the organic EL layer while still enabling effective laser-induced removal of the common functional layer

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The oxide semiconductor layer is designed as a temporary sacrificial structure that is removed after serving its purpose of enabling common functional layer removal. It is formed specifically for the laser processing step and then removed together with the common functional layer, avoiding the need for permanent metal structures that would continuously reflect light

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Productivity

If a vapor deposition mask is used to form common functional layers, then common functional layers can be formed for multiple subpixels, but it is technically difficult to shield the non-display region with the vapor deposition mask

Engineering Contradiction:

Improveformation of common functional layerVSAvoidshielding of non-display region

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The oxide semiconductor layer is formed in advance in the non-display region before the common functional layer deposition. This preliminary structure serves as a sacrificial layer that enables subsequent selective removal of the common functional layer from the non-display region through laser irradiation, allowing the vapor deposition mask to remain simple without complex shielding patterns

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The oxide semiconductor layer acts as an intermediary sacrificial structure that facilitates the removal of the common functional layer. It is positioned between the substrate and the common functional layer, and when irradiated with laser light, it converts light to heat to sublimate the common functional layer above it, enabling selective removal without complex mask designs

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

This configuration enables the effective removal of the common functional layer from the non-display region while minimizing damage to the functional layer in the display region, thus enhancing the performance and reliability of the organic EL display device.

Implementation Method 1

the common functional layer is provided to extend from the display region to the non-display region, a second opening is provided in a frame-like shape to surround the through hole in a plan view and expose the oxide semiconductor layer in the common functional layer

Methodology Applied

Scientific EffectLaser irradiation: Laser

Implementation Method 2

it is conceived that a metal layer capable of converting light to heat is provided in the non-display region and the metal layer is irradiated with laser light to sublimate the common functional layer

Methodology Applied

Scientific EffectSublimation: Sublimation

Data Source

PatentUS12219797B2Display device including a frame-like shape oxide semiconductor layer

Publication Date: 2025.02.04 SHARP KK

AI summary

An aspect of the disclosure, in a non-display region, an oxide semiconductor layer is provided in a frame-like shape along a peripheral edge of a through hole, a first opening is provided in a first inorganic insulating film so as to surround the through hole in a plan view and expose the oxide semiconductor layer in the non-display region, a common functional layer is provided so as to extend from a display region to the non-display region, a second opening is provided in a frame-like shape so as to surround the through hole in a plan view and expose the oxide semiconductor layer in the common functional layer, and a second inorganic insulating film is in contact with the oxide semiconductor layer via the second opening.