OLED Contact Hole Reverse Tapering for Low Resistance
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Solution Overview
Problem
The complexity of the process and high resistance in contact holes of organic light-emitting diode (OLED) display devices hinder the reduction of power consumption and heat, affecting the reliability and efficiency of these devices as they increase in resolution and size.
Innovation Solution
The OLED display device incorporates a contact-hole structure with a reverse-tapered sidewall and a conductive filler, allowing direct contact between the connection electrode and the second electrode, reducing contact resistance and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional contact hole structures are used in OLED display devices, then the device can be manufactured with standard processes, but the contact resistance remains high leading to increased power consumption and heat generation
Solution Approach 1:
The patent inverts the conventional contact hole geometry by creating a reverse-tapered structure where the opening at the top is smaller than the bottom opening. This inversion allows the connection electrode to extend further into the contact area, creating multiple contact points and significantly reducing contact resistance between the connection electrode and the second electrode of the light-emitting element.
Solution Approach 2:
The patent extends the connection electrode vertically into the contact hole structure, creating a three-dimensional contact path. The connection electrode protrudes into the contact area from the insulation film, establishing direct contact with the second electrode through the emission layer, thereby reducing contact resistance in the vertical dimension.
2Measurement precision
If the number of pixels is increased to improve resolution, then the display quality improves, but the process complexity increases and yield decreases
Solution Approach 1:
The patent segments the contact structure into distinct functional zones: the insulation film covering the power line, the contact hole penetrating through the insulation film, the connection electrode extending into the contact hole, and the passivation film with its own contact area. This segmentation allows each component to be optimized independently, simplifying the manufacturing process while maintaining high resolution.
3Use of energy by moving object
If contact hole resistance is reduced to lower power consumption, then energy efficiency improves, but the contact hole structure becomes more complex
Solution Approach 1:
The patent applies local quality by creating a reverse-tapered contact hole structure specifically in the contact area, while the rest of the device maintains standard structure. The passivation film is selectively removed or thinned only in the contact area to expose the connection electrode, allowing reduced contact resistance locally without complicating the entire device structure.
Data Source
AI summary
An organic light-emitting diode display device includes a substrate in which an emission area and a non-emission area are defined, a power line provided on the substrate, at least one insulation film covering the power line, a light-emitting element provided above the at least one insulation film, a connection electrode connected to the power line, and extending onto the at least one insulation film, and a passivation film including a contact area where a portion of the connection electrode is exposed in the non-emission area, wherein the light-emitting element includes a first electrode, an emission layer, and a second electrode that are stacked in order, and the second electrode is in direct contact with the connection electrode in the contact area.