TFT Substrate Three-Mask Process Double-Layer Conductive Structure
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Solution Overview
Problem
The manufacturing process of thin film transistor substrates for liquid crystal display devices with horizontal electric field applications is complex and costly due to the requirement of multiple mask processes, which increases the production costs and complexity.
Innovation Solution
A simplified three-mask process is introduced for fabricating the thin film transistor substrate, utilizing a gate line, data line, and common electrode with double conductive layers, and a semiconductor pattern to form a horizontal electric field, reducing the number of mask processes and simplifying the fabrication method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple mask processes are used to fabricate thin film transistor substrate, then manufacturing precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple mask processes into a single mask process by using a dual-layer conductive structure. The first conductive layer is patterned to form gate lines and common lines, while the second conductive layer is patterned in the same step to form pixel electrodes and common electrodes. This merging of processes reduces fabrication complexity while maintaining pattern formation precision through the protective film that prevents short circuits between adjacent electrodes.
Solution Approach 2:
The patent introduces a vertical dimension by using a dual-layer conductive structure with a protective film between layers. Instead of forming all conductive patterns in separate planar mask steps, the invention uses stacked conductive layers (first and second conductive layers) separated by a protective film, transforming a 2D patterning problem into a 3D structured solution that simplifies the overall process.
2Manufacturing precision
If multiple mask processes are used to fabricate thin film transistor substrate, then manufacturing precision is improved, but productivity decreases
Solution Approach 1:
The patent merges multiple sequential mask processes into a single mask process by simultaneously patterning the first and second conductive layers. This reduces the total number of fabrication steps, increases production throughput, and improves productivity while maintaining manufacturing precision through the protective film structure that ensures accurate pattern formation without short circuits.
3Manufacturing precision
If multiple mask processes are used to fabricate thin film transistor substrate, then manufacturing precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent combines multiple mask processes into one, reducing the number of photolithography and etching steps required. This merging significantly reduces manufacturing costs by decreasing material consumption, equipment usage time, and labor requirements, while the protective film structure ensures that pattern formation precision is maintained despite the reduced number of process steps.
4Area of stationary object
If aperture ratio is increased in horizontal electric field liquid crystal display, then display performance is improved, but device complexity increases
Solution Approach 1:
The patent uses a dual-layer conductive structure with a protective film to enable larger aperture ratios. By forming pixel electrodes and common electrodes in stacked layers separated by a protective film, the design allows electrodes to extend closer together without short circuits, increasing the transparent area and aperture ratio while the layered structure manages the complexity of having multiple electrodes in close proximity.
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 reduces manufacturing costs, improves productivity, and enhances the aperture ratio by using a double-layer conductive structure and a protective film, while maintaining the wide viewing angle advantage of horizontal electric field liquid crystal displays.
Implementation Method 1
a liquid crystal display device controls light transmittance of a liquid crystal having a dielectric anisotropy using an electric field
Implementation Method 2
a liquid crystal having a dielectric anisotropy is rotated in accordance with an electric field formed by a data signal from the pixel electrode and a common voltage Vcom from the common electrode
Data Source
AI summary
A method of fabricating a liquid crystal display device includes in a first mask process, forming a first mask pattern group including a gate line, a gate electrode connected to the gate line and a common line parallel to the gate line that have a first conductive layer group structure having at least double conductive layers. A second mask process forms a gate insulating film on the first mask pattern group and a semiconductor pattern thereon. A third mask process forms a third mask pattern group including a data line, a source electrode connected to the data line and a drain electrode opposite the source electrode that have a second conductive layer group structure having at least double conductive layers, and a protective film interfacing with the third mask pattern group on the gate insulating film.