Stacked Color Filter Thin Film Transistor Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing process of liquid crystal displays with a color filter on a thin film transistor (COT) structure is complex, leading to reduced manufacturing yields due to the need for multiple mask processes and alignment issues when forming color filters on the same substrate as thin film transistors, which complicates achieving high aperture ratios and resolution.
Innovation Solution
A thin film transistor substrate design where multiple color filters are stacked at non-aperture areas, with one color filter acting as an intermediate insulating layer, eliminating the need for a black matrix and reducing the number of masking processes, thereby simplifying the manufacturing process and ensuring high aperture ratios without alignment concerns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If color filters are formed on the same substrate as thin film transistors using multiple mask processes, then color filter functionality is achieved, but manufacturing complexity increases and manufacturing yield decreases
Solution Approach 1:
The patent combines the color filter formation process with the thin film transistor manufacturing process by using the same substrate and integrating color filter layers into the existing multi-layer structure. This merging eliminates the need for separate mask processes for color filters, reducing manufacturing complexity while maintaining both color filter functionality and TFT performance
Solution Approach 2:
The patent makes the substrate and manufacturing process universal by designing a structure where the same substrate serves both as the base for thin film transistors and as the support for color filter layers. The multi-layer configuration allows the manufacturing process to serve multiple functions simultaneously, achieving both pixel formation and color filtering without requiring separate specialized processes
2Ease of manufacture
If color filters are formed on the same substrate as thin film transistors, then alignment margins become critical, but this reduces aperture ratio
Solution Approach 1:
The patent transitions from a two-dimensional planar arrangement to a three-dimensional stacked configuration by placing color filter layers above the thin film transistor layers. This vertical stacking in another dimension (the vertical axis) eliminates the need for lateral alignment margins, allowing the aperture area to be maximized without compromising alignment precision
3Manufacturing precision
If multiple mask processes are used to form color filters on thin film transistors, then color filter precision is achieved, but manufacturing yield decreases
Solution Approach 1:
The patent segments the color filter structure into multiple distinct layers (first color filter layer, second color filter layer, third color filter layer) that can be formed separately and then stacked. This segmentation allows each layer to be optimized independently while reducing the cumulative alignment errors that would result from multiple mask processes, thereby improving manufacturing yield
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The present disclosure relates to a thin film transistor substrate having a color filter layer. The present disclosure provides a thin film transistor substrate comprising: a plurality of pixel areas disposed in a matrix manner on a substrate, each pixel area including an aperture area and a non-aperture area; a first color filter and a second color filter stacked at the non-aperture area on the substrate; an overcoat layer disposed on the first color filter and the second color filter; a semiconductor layer disposed at the non-aperture area on the overcoat layer; a gate insulating layer and a gate electrode stacked on a middle portion of the semiconductor layer; a third color filter at the non-aperture area on the semiconductor layer and the gate electrode; and a source electrode and a drain electrode disposed on the third color filter.