Copper Wiring Area Reduction for Display Screen Coloring
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Solution Overview
Problem
Display devices using copper wiring face issues with screen coloring due to reflected external light, particularly reddish tint, while striving to maintain high aperture ratios, as copper wiring has high reflectance at long wavelengths and existing light shielding methods complicate production and inhibit aperture ratio improvement.
Innovation Solution
The display device incorporates copper wiring with a smaller area in pixel regions containing red-colored layers compared to those with other colored layers, utilizing copper alloys or copper oxide/nitride layers, and includes a light shielding portion to minimize reflected light, thereby reducing screen reddishness without compromising aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper wiring is used to reduce signal delay and improve aperture ratio, then electrical conductivity and aperture ratio are improved, but screen coloring occurs due to high reflectance at long wavelengths
Solution Approach 1:
A light shielding film is introduced as an intermediary layer between the copper wiring and the external environment. This film selectively blocks reflected light at long wavelengths (red region) while allowing other wavelengths to pass, thereby eliminating screen coloring without affecting the electrical conductivity or aperture ratio of the copper wiring
Solution Approach 2:
The light shielding film is designed with specific optical properties to selectively absorb or block red light (long wavelengths). By controlling the optical characteristics of this film, the harmful red reflection from copper wiring is suppressed while maintaining transparency to other colors, thus resolving the screen coloring issue
2Object-generated harmful factors
If light shielding portion is provided on color filter substrate to reduce reflected light, then screen coloring is reduced, but aperture ratio is reduced due to additional light shielding structures
Solution Approach 1:
Instead of adding light shielding structures in the planar dimension on the color filter substrate, the solution moves to a different dimensional approach by applying a thin light shielding film directly on the copper wiring surface. This vertical/dimensional approach blocks reflected light without occupying additional pixel area, thus maintaining high aperture ratio
3Reliability
If wiring area is increased to reduce resistance and signal delay, then electrical conductivity is improved, but reflected light increases causing more screen coloring
Solution Approach 1:
The light shielding film converts the harmful effect of copper's high reflectance into a beneficial situation. By selectively blocking only the problematic long wavelength (red) light while allowing other wavelengths to reflect, the film transforms the potential screen coloring issue into an opportunity to enhance display color accuracy without compromising the electrical benefits of large copper wiring areas
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 configuration effectively suppresses screen coloring from reflected light, ensuring high display quality with improved aperture ratios, even in bright environments, by controlling the area of copper wiring and using light shielding to manage reflectance across different colored layers.
Implementation Method 1
the copper wiring has a high reflectance to the light at a long wavelength (600 nm to 780 nm). The light of the long wavelength is reddish light
Data Source
AI summary
The present invention provides a display device using a copper wiring and having high display properties in which without preventing a higher aperture ratio of the pixel, coloring of a screen due to reflected light of external light produced within the display device can be prevented. The display device according to the present invention is a display device including a plurality of pixel regions, wherein each of the pixel regions includes a copper wiring containing copper or an alloy thereof, and a red-colored layer and a colored layer of another color; and an area of the copper wiring is smaller in the pixel region including the red-colored layer than in the pixel region including the colored layer of another color, the area of the copper wiring reflecting incident light entering from the display surface side of the display device.