OLED Substrate Hole Isolation Structure for Moisture Protection

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Solution Overview

Problem

In display apparatuses, external moisture can penetrate through substrate holes and damage adjacent light emitting devices by moving through the light emitting layer.

Innovation Solution

The display apparatus includes a substrate hole with an isolation structure, such as an undercut structure, between the substrate hole and the light emitting devices, which prevents external moisture from reaching the light emitting devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If substrate holes are used to insert peripheral devices, then device integration is improved, but moisture penetration damage increases

Engineering Contradiction:

Improvedevice integrationVSAvoidmoisture penetration damage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The substrate hole structure is segmented into multiple functional zones: the through-hole region for device insertion, the undercut isolation region for moisture blocking, and the light-emitting region. This segmentation allows the hole to simultaneously serve as both an access channel for peripheral devices and a blocked pathway for moisture, resolving the contradiction between device integration and moisture protection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The undercut isolation structure acts as an intermediary element between the substrate hole and the light-emitting layer. This intermediate structure blocks moisture from reaching the light-emitting layer while allowing the substrate hole to remain open for peripheral device insertion, thus mediating between the conflicting requirements of device access and moisture protection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If isolation structures are added to block moisture, then light emitting device protection is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvelight emitting device protectionVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The isolation structure is merged with the existing substrate hole formation process. The undercut isolation structure is created as an integrated part of the substrate hole fabrication sequence, combining the moisture-blocking function with the device-access function in a single unified structure, thereby reducing overall manufacturing complexity despite adding protective functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The substrate hole structure is designed with multi-functionality: it serves as both an access channel for peripheral devices and a pathway blocked by the undercut isolation structure for moisture protection. The light-emitting layer is also designed to extend over the isolation structure, making the same region serve multiple functional purposes and reducing the need for separate dedicated structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Area of stationary object

If light emitting layer extends to substrate hole, then device area is improved, but moisture damage risk increases

Engineering Contradiction:

Improvedevice areaVSAvoidmoisture damage risk

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The light-emitting layer is given different properties in different locations: in the central region it forms the light-emitting structure, while in the peripheral region extending toward the substrate hole it serves as an isolation barrier. This local differentiation of function allows the light-emitting layer to simultaneously maximize device area and provide moisture protection at critical locations.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The solution moves from a two-dimensional planar layout to a three-dimensional structure by having the light-emitting layer extend vertically over the undercut isolation structure. This dimensional transition allows the light-emitting layer to cover the substrate hole periphery without creating a direct moisture pathway, as the undercut structure creates a physical barrier in the vertical dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS20250184417A1Display apparatus including substrate hole

Publication Date: 2025.06.05 LG DISPLAY CO LTD

AI summary

Disclosed herein is an organic light emitting display apparatus. The organic light emitting display apparatus includes at least one thin film transistor and light emitting device on substrate, the light emitting device is apart from the substrate hole, and at least one isolation structure is disposed between the substrate hole and the light emitting device. Each thin film transistor includes source/drain electrodes, each light emitting device includes a first electrode, a light emitting layer, and a second electrode, the organic light emitting display apparatus includes a connection electrode connecting one of the source/drain electrodes of the thin film transistor to the first electrode of the light emitting device, and a planarization layer is disposed between the thin film transistor and the light emitting device. The isolation structure includes at least one undercut structure, and a height of each undercut structure is greater than a thickness of the light emitting layer.