Display Edge Dummy Pattern for Uniform Photoresist Coating

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Solution Overview

Problem

The existing display device manufacturing processes face challenges in minimizing defects and reducing process time and cost due to the inability to coat photoresist evenly on the side surfaces of color conversion layers, leading to damage during etching processes.

Innovation Solution

Incorporating a dummy pattern in the non-emission areas with a step shape that decreases in height towards the non-display area, which helps in maintaining a thin photoresist thickness of about 2.0 μm or less, thereby preventing damage to the color conversion layer and improving the defect rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If photoresist is coated on the side surfaces of color conversion layers, then etching protection is improved, but photoresist thickness uniformity deteriorates due to step differences

Engineering Contradiction:

Improveetching protectionVSAvoidphotoresist thickness uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The dummy pattern is formed in advance before photoresist coating, creating a gradual height transition structure that prevents photoresist thickness variation during subsequent coating and etching processes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The dummy pattern acts as an intermediary structure between the substrate and the color conversion layer, providing a gradual height transition that eliminates abrupt step differences and enables uniform photoresist coating

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of time

If photoresist thickness is reduced to 2.0 μm or less, then process time and cost are reduced, but photoresist coating difficulty increases due to step differences

Engineering Contradiction:

Improveprocess timeVSAvoidphotoresist coating difficulty

Core Design Contradiction:

Loss of timeVSEase of manufacture

Solution Approach 1:

The dummy pattern is formed beforehand to create a gradual height transition, enabling thin photoresist coating without the usual difficulties associated with step differences

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The dummy pattern changes the height parameter gradually across the structure, transforming abrupt step differences into a continuous gradient that allows uniform thin photoresist coating

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If color conversion layer is formed without dummy pattern, then manufacturing complexity is reduced, but damage during etching process increases

Engineering Contradiction:

Improvemanufacturing complexityVSAvoiddamage during etching

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The dummy pattern is formed in advance to provide etching protection, preventing damage to the color conversion layer during subsequent etching processes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The dummy pattern serves as a protective cushion structure that absorbs or distributes etching forces, preventing direct damage to the color conversion layer

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS20240006567A1Display device and method of manufacturing the same

Publication Date: 2024.01.04 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a substrate including a display area and a non-display area, a first pixel disposed at an outermost side of the display area of the substrate, a dummy pattern extending from the first pixel to the non-display area, and a signal pad disposed outside the dummy pattern and electrically connected to the first pixel. The first pixel includes a pixel circuit layer including a transistor disposed on the substrate, a display element layer disposed on the pixel circuit layer and including light emitting elements, and a first color conversion layer disposed on the display element layer. The dummy pattern is disposed on the pixel circuit layer in the non-display area adjacent to the first color conversion layer, and an upper surface of the dummy pattern is lower than an upper surface of the first color conversion layer.