TFT Substrate Data Line Segmentation for Aperture Ratio

Solution Overview

Problem

Conventional TFT substrates face challenges in enhancing performance and processing efficiency due to the semiconductor layer remaining under data wiring, which reduces the aperture ratio and can cause afterimages.

Innovation Solution

A TFT substrate is designed with a lattice arrangement of gate and data lines, where the data line includes a transparent electrode lower layer and a conductive upper layer, allowing simultaneous patterning to avoid semiconductor layer remnants under the data wiring, thereby maintaining aperture ratio and preventing afterimages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single mask is used to etch semiconductor layer and data wiring simultaneously, then processing efficiency is improved, but aperture ratio is reduced and afterimages are formed due to semiconductor layer remaining under data wiring

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidaperture ratio

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The data wiring is divided into two separate layers: a lower layer (first data wiring layer) and an upper layer (second data wiring layer). The lower layer is formed first, then the semiconductor layer is patterned, and finally the upper layer is formed to cover and isolate the semiconductor layer from the data wiring function, preventing afterimages while maintaining processing efficiency through coordinated layer formation

Inventive Principle:

Principle #1Segmentation

2Productivity

If a single mask is used to etch semiconductor layer and data wiring simultaneously, then processing efficiency is improved, but afterimages are formed due to semiconductor layer remaining under data wiring

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidafterimage prevention

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The data wiring is divided into two separate layers: a lower layer (first data wiring layer) and an upper layer (second data wiring layer). The lower layer is formed first, then the semiconductor layer is patterned, and finally the upper layer is formed to cover and isolate the semiconductor layer from the data wiring function, preventing afterimages while maintaining processing efficiency through coordinated layer formation

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lower data wiring layer acts as an intermediary structure that supports the semiconductor layer during processing, while the upper data wiring layer provides the actual data transmission function. This intermediary lower layer enables the semiconductor layer to be completely removed or isolated without compromising the data wiring functionality, thus preventing afterimages

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7960219B2Thin-film transistor substrate and method of fabricating the same

Publication Date: 2011.06.14 SAMSUNG DISPLAY CO LTD

AI summary

A thin-film transistor (“TFT”) substrate includes an insulating substrate, a gate line and a data line which are insulated from each other, disposed on the insulating substrate and are arranged in a lattice, and a pixel electrode which is electrically connected to the gate line and the data line by a switching device. The data line includes a lower layer which is formed of a transparent electrode, and an upper layer which is disposed directly on the lower layer.