Bendable Display Panel Sloped Deep Hole Etching

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Solution Overview

Problem

In the fabrication of bendable OLED display panels, the metal wires face difficulties in climbing the steep taper corners of deep holes, leading to poor step coverage and a higher likelihood of breakage, resulting in open circuits and signal loss.

Innovation Solution

A method involving dry etching to form deep holes with a slope in the inorganic film layer, followed by filling these holes with an organic material and forming a metal wiring layer on the inorganic and organic film layers, improving the metal wiring's climbing ability and reducing signal disconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the inorganic layer is completely etched away in the bending area to enable flexibility, then the bendability is improved, but the metal wire step coverage deteriorates due to steep taper corners in deep holes

Engineering Contradiction:

ImprovebendabilityVSAvoidmetal wire step coverage

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies different treatments to different regions: the inorganic layer is selectively removed only in the bending area (deep hole region) while being retained in the display area. This local differentiation enables flexibility where needed while maintaining structural integrity and proper metal wire formation where required.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent performs preliminary filling of the deep hole with organic material before forming the metal wire layer. This preliminary action creates a tapered filling structure that prevents the metal wire from detaching at the step, solving the step coverage problem before it occurs.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the deep hole is filled with organic material and metal wire is electroplated, then the electrical connection is established, but the metal wire becomes too thin at the step and prone to breakage

Engineering Contradiction:

Improveelectrical connectionVSAvoidmetal wire thickness at step

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent introduces organic material as an intermediary substance that fills the deep hole and provides a tapered supporting structure. This intermediary prevents the metal wire from detaching at the step during electroplating, ensuring adequate wire thickness and preventing breakage while maintaining electrical connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The organic material filling acts as a cushioning structure prepared in advance. The tapered shape of the filling provides gradual support that prevents stress concentration at the step, cushioning against potential wire breakage before it occurs during subsequent processing and bending operations.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Stability of the object's composition

If the inorganic layer is retained in the bending area, then the structural integrity is maintained, but the flexibility and bendability are reduced

Engineering Contradiction:

Improvestructural integrityVSAvoidflexibility

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent selectively removes the inorganic layer only in the bending area (deep hole region) while retaining it in the display area. This local differentiation maintains structural integrity where needed while enabling flexibility in the bending region, resolving the contradiction between these two requirements.

Inventive Principle:

Principle #3Local quality

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 approach enhances the bending performance and reduces signal loss by improving the metal wiring's ability to climb the slope, thereby increasing the quality and reliability of the display panel.

Implementation Method 1

dry etching the deep hole region to form a deep hole having a slope

Methodology Applied

Scientific EffectDry etching:

Implementation Method 2

filling the deep hole with an organic material to form an organic film layer

Methodology Applied

Scientific EffectFilling:

Data Source

PatentUS10847596B2Bendable display panel and fabricating method thereof

Publication Date: 2020.11.24 WUHAN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO LTD

AI summary

A bendable display panel and a fabricating method thereof are disclosed, including: providing the flexible substrate and the inorganic film layer formed on the flexible substrate, the inorganic film layer includes a deep hole region disposed in a bending area; dry etching the deep hole region to form a deep hole having a slope, and a bottom of the deep hole is located on the flexible substrate; filling the deep hole with an organic material to form an organic film layer; and forming a metal wiring layer on the inorganic film layer and the organic film layer. In the method, a deep hole having a slope is formed by gas dry etching. The etching method can control the slope to improve the climbing ability of the metal wiring, and reduce or avoid the loss of electrical signal caused by disconnection of the metal wiring, thereby improving the display panel quality.