Electro-optical Device Pillar Protrusions Contact Area
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Solution Overview
Problem
Existing electro-optical devices, such as liquid crystal devices, face issues with large contact holes that lead to pixel electrode depressions and elevations, affecting display quality and requiring additional metal materials for plug formation, increasing manufacturing costs and reducing productivity.
Innovation Solution
The use of pillar-shaped protrusions on an insulating film between the substrate and pixel electrodes, with a conductive layer overlapping these protrusions, allows for electrical connection without large contact holes, using existing films and avoiding the need for special metal plugs, thus reducing surface depressions and elevations and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If large contact holes are used to electrically connect pixel electrodes to underlying conductive layers, then electrical connection is achieved, but surface depressions and elevations increase, reducing display quality
Solution Approach 1:
The patent transitions from horizontal contact holes to vertical pillar-shaped protrusions. The conductive layer is positioned on top of the pillar protrusions rather than requiring lateral penetration through the insulating film, effectively changing the connection geometry from horizontal to vertical dimension.
Solution Approach 2:
The pillar-shaped protrusions are formed in advance on the insulating film before the conductive layer is deposited. This preliminary formation of elevated structures ensures that the conductive layer naturally makes contact at the highest points, preventing surface depressions and elevations during subsequent manufacturing steps.
2Reliability
If plug structures with special metal materials are used to fill contact holes, then electrical connection is improved, but manufacturing cost increases due to additional metal materials
Solution Approach 1:
The existing conductive layer in the device serves dual purposes: it functions as both the inter-layer connection and the plug material. The conductive layer is deposited to cover the pillar protrusions, and its portions at the highest points automatically form the connection plugs, eliminating the need for separate plug formation processes and special metal materials.
Solution Approach 2:
The conductive layer is designed to perform multiple functions simultaneously: it provides in-plane electrical connection between pixel electrodes, serves as vertical connection plugs through contact holes, and maintains surface flatness. This multi-functionality eliminates the need for dedicated plug materials like tungsten.
3Reliability
If sputtering and chemical mechanical polishing steps are performed to thicken metal film and smooth insulating film, then plug formation is achieved, but manufacturing time increases, reducing productivity
Solution Approach 1:
The patent extracts and eliminates the time-consuming sputtering and chemical mechanical polishing steps from the manufacturing process. By using the existing conductive layer deposition process and the pillar-shaped protrusion geometry, the method achieves plug formation without requiring additional thickening or smoothing operations.
Solution Approach 2:
The plug formation process is merged with the existing conductive layer deposition process. The same deposition step that creates the conductive inter-layer also forms the vertical connection plugs, combining two previously separate operations into one efficient process step.
4Manufacturing precision
If contact holes are made smaller to prevent surface depressions, then display quality improves, but electrical connection reliability may be compromised
Solution Approach 1:
The insulating film maintains its original thickness and properties in most areas, but localized pillar-shaped protrusions are created only at specific contact points. This localized modification ensures electrical connection reliability at the protrusion tips while maintaining surface flatness in the surrounding 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 results in a more efficient and cost-effective electro-optical device with improved display quality by minimizing contact area size and eliminating the need for additional metal deposition, enhancing productivity and surface smoothness for oriented film formation.
Implementation Method 1
the pixel electrodes are deposited on one side of the second insulating film
Data Source
AI summary
An electro-optical device including a pixel electrode provided over one side of a substrate, a conductive layer provided between the substrate and the pixel electrode, and a relay electrode provided between the substrate and the conductive layer. The conductive layer includes a first conduction section protruding toward the pixel electrode and a second conduction section protruding toward the relay electrode. The first conduction section is cylindrical-shape having an upper surface which is attached to the pixel electrode, and having a side surface sloping from the upper surface. The pixel electrode is electrically connected to the relay electrode through the conduction section.