Dummy Patterns for Display Device Conductive Uniformity

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Solution Overview

Problem

In display device manufacturing, conductive patterns at the edge of the display area are often non-uniform due to a loading effect from local pattern density changes, leading to potential short circuits during the exposing and developing processes.

Innovation Solution

Incorporating dummy patterns of specific sizes and ratios in the peripheral areas, which are electrically insulated and disposed on the same layer as the conductive patterns, to mitigate the effects of pattern density differences and ensure uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If photoresist is coated and exposing and developing processes are performed during the manufacture of the display device, then conductive patterns can be formed, but the photoresist disposed at an edge of the display area may be partially developed due to a sudden pattern density change, leading to non-uniform conductive patterns and potential short circuits

Engineering Contradiction:

Improveuniformity of conductive patternsVSAvoidloading effect from pattern density difference

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by introducing dummy patterns specifically at the peripheral area where pattern density suddenly changes. These dummy patterns have a different area ratio (greater than 50%) compared to normal pixel patterns, creating a gradual transition zone that mitigates the loading effect and prevents photoresist development issues at the edges.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The dummy patterns are pre-formed in the peripheral area before the actual pixel patterns are created. This preliminary action establishes a gradual pattern density transition zone that prevents the sudden density change from causing loading effects during the exposing and developing processes.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the dummy pattern area ratio is increased to mitigate loading effects, then uniformity of conductive patterns is improved, but the device structure becomes more complex

Engineering Contradiction:

Improveuniformity of conductive patternsVSAvoidstructure with dummy patterns

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The dummy patterns are merged with the existing pixel patterns and formed using the same photoresist coating, exposing, and developing processes. This integration approach allows the dummy patterns to be created without adding separate manufacturing steps, thereby reducing the increase in device complexity while still achieving the desired uniformity improvement.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11302753B2Display device

Publication Date: 2022.04.12 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes: a substrate that includes a first area and a second area; a plurality of pixels included in the first area; and a dummy pattern included in the second area, wherein a size of the dummy pattern is smaller than a pixel area corresponding to a first pixel among the plurality of pixels, a ratio of an area occupied by a pixel pattern of the first pixel with respect to the pixel area is a first value, a ratio of an area occupied by the dummy pattern with respect to a dummy area is a second value that is greater than the first value, and the dummy area and the pixel area have the same size as each other.