OLED Substrate Single Patterning Process for Stability

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Solution Overview

Problem

Existing OLED substrate manufacturing processes face issues with stability due to light exposure affecting thin film transistors and incur high costs and reduced productivity from separate patterning of anode and pixel defining layers.

Innovation Solution

A single patterning process is used to form first electrodes and a pixel defining layer with pixel partition walls on an OLED substrate, where the pixel defining layer serves as an etch protection layer, and the first electrodes are made of conductive and reflective materials like ITO/Ag/ITO to prevent light exposure and reduce patterning steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If separate patterning processes are used for anode and pixel defining layers, then manufacturing precision can be maintained, but productivity decreases and manufacturing cost increases

Engineering Contradiction:

Improvepatterning precisionVSAvoidmanufacturing efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines the patterning of the anode layer and pixel defining layer into a single patterning process. The pixel defining layer is formed first as a patterned layer, then the anode layer is deposited and patterned simultaneously in one exposure and development step, eliminating the need for separate patterning processes and photoresist removal steps.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The pixel defining layer serves multiple functions: it defines the pixel boundaries, serves as a mask for anode patterning, and acts as a structural element of the OLED device. This multi-functionality allows it to replace the traditional photoresist layer, eliminating the need for separate photoresist application and removal steps.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If traditional separate patterning processes are used, then process control is maintained, but manufacturing cost increases due to additional photoresist and process steps

Engineering Contradiction:

Improveprocess controlVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the photoresist layer from the manufacturing process by using the pixel defining layer itself as the patterning mask. This eliminates the need for photoresist materials and the associated costs of photoresist application, exposure, development, and removal steps.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The pixel defining layer serves its own dual purpose: it is both the functional pixel boundary structure and the patterning mask for the anode layer. This self-service approach eliminates the need for external photoresist materials and simplifies the manufacturing process.

Inventive Principle:

Principle #25Self-service

3Manufacturing precision

If light exposure is applied during manufacturing, then patterning is achieved, but thin film transistor stability deteriorates due to light damage

Engineering Contradiction:

Improvepatterning capabilityVSAvoidthin film transistor stability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent performs the patterning operation before the thin film transistor is fully assembled or protected. By using the pixel defining layer as the mask during anode patterning, the need for subsequent light exposure steps is eliminated, thereby protecting the thin film transistor from light damage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the potential harm of light exposure to thin film transistors by using the pixel defining layer as a permanent mask that eliminates the need for photoresist removal steps that would require additional light exposure, thereby protecting the thin film transistor from light damage while maintaining patterning capability.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 method enhances the stability of the OLED substrate by protecting thin film transistors from light, reduces manufacturing costs, and increases productivity by eliminating the need for additional patterning steps and photoresist usage, while improving the aperture ratio.

Implementation Method 1

the pixel defining layer serves as an etch protection layer, and the first electrodes are made of conductive and reflective materials like ITO/Ag/ITO to prevent light exposure

Methodology Applied

Scientific EffectLight blocking: Absorption (EM radiation)

Implementation Method 2

the first electrodes are made of conductive and reflective materials like ITO/Ag/ITO to prevent light exposure

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS10930518B2OLED substrate and manufacturing method thereof, display device and manufacturing method thereof

Publication Date: 2021.02.23 BOE TECHNOLOGY GROUP CO LTD

AI summary

The present disclosure provides an OLED substrate and a manufacturing method thereof, a display device and a manufacturing method thereof, and belongs to the technical field of display technology. A manufacturing method for an OLED substrate of the present disclosure includes: forming, by a patterning process, a pattern including first electrodes of OLED devices and a pixel defining layer provided above the first electrodes above the base substrate, wherein the pixel defining layer includes a plurality of pixel partition walls spaced apart from each other, each of the pixel partition walls defines one of the first electrodes.