Shield Pattern Under Contact Hole Prevents Light Leakage in OLED
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Solution Overview
Problem
Organic electroluminescent display devices face issues with light leakage and unreliable contact properties due to the structure of contact holes, which affect display quality and reliability.
Innovation Solution
The implementation of shield patterns made from the same material and layer as the gate line under the contact holes prevents etching of the gate insulating layer, minimizing step differences and ensuring reliable contact between electrodes, thereby preventing light leakage and improving display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact holes are formed to connect electrodes, then electrical connection is achieved, but light leakage occurs through the contact holes
Solution Approach 1:
A shield pattern is introduced as an intermediary element between the contact hole and the organic electroluminescent layer. This shield pattern blocks light from leaking through the contact hole while maintaining the electrical connection function of the contact hole structure.
Solution Approach 2:
The contact hole structure is segmented into multiple functional zones: the contact hole itself for electrical connection, and the surrounding shield pattern for light blocking. This segmentation allows each component to perform its specific function without interfering with the other.
2Ease of manufacture
If gate insulating layer is etched during contact hole formation, then contact holes are created, but step differences are generated affecting contact reliability
Solution Approach 1:
The shield pattern is formed in advance during the gate line formation process, before contact hole etching. This preliminary action ensures that the shield pattern is already in place to protect the gate insulating layer and minimize step differences when contact holes are subsequently formed.
Solution Approach 2:
The shield pattern acts as a cushioning structure that prevents excessive etching of the gate insulating layer. By having this protective structure in place beforehand, the harmful effect of step differences is minimized during the contact hole formation process.
3Illumination intensity
If transparent conductive material is used for first electrode, then light emission is enabled, but contact reliability through contact holes is compromised
Solution Approach 1:
The shield pattern serves as an intermediary structure that resolves the conflict between light emission and contact reliability. It allows the transparent conductive material to maintain its light-emitting function while the shield pattern provides the necessary protection for reliable contact formation.
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
The use of shield patterns effectively blocks light from leaking through contact holes, enhancing display quality and maintaining reliable contact properties, thus addressing the limitations of existing organic electroluminescent display devices.
Implementation Method 1
the implementation of shield patterns made from the same material and layer as the gate line under the contact holes prevents etching of the gate insulating layer, minimizing step differences and ensuring reliable contact between electrodes, thereby preventing light leakage and improving display quality
Data Source
AI summary
An organic electroluminescent display device includes: a substrate; a gate line, a data line and a power line on the substrate; a switching element connected to the gate line and the data line; a driving element connected to the switching element, the driving element including a driving drain electrode; a first passivation layer on the switching element and the driving element, the first passivation layer having a first contact hole exposing the driving drain electrode; a first shield pattern under the first contact hole, the first shield pattern including a same material and a same layer as the gate line; a first electrode on the first passivation layer, the first electrode connected to the driving drain electrode through the first contact hole; an organic electroluminescent layer on the first electrode; and a second electrode on the organic electroluminescent layer.