OLED EL Layer Patterning for Moisture-Resistant Display Manufacturing
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Solution Overview
Problem
Moisture penetration through exposed end portions of the organic electroluminescent layer in OLED display devices leads to degradation, necessitating effective countermeasures during manufacturing.
Innovation Solution
The manufacturing method involves forming organic EL layers with end surfaces in contact with partitions, and using etching to remove excess portions, ensuring the end surfaces are covered by protective films and upper electrodes, with partitions' thickness controlled to minimize moisture ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the organic EL layer is patterned by etching, then the display device can be manufactured with the required structure, but the end portion of the organic EL layer becomes exposed to the atmosphere and vulnerable to moisture penetration
Solution Approach 1:
A protective film is formed covering the entire surface of the organic EL layer before etching is performed. This preliminary protective action ensures that even though etching exposes the end portions of the organic EL layer, the protective film remains in place to prevent moisture penetration, thus resolving the contradiction between ease of manufacture and reliability
Solution Approach 2:
The protective film acts as an intermediary layer between the organic EL layer and the atmosphere. It mediates the exposure caused by etching while preventing direct contact between moisture and the organic EL layer, thereby maintaining both manufacturability and moisture resistance
2Reliability
If the thickness of partitions is increased to prevent moisture ingress, then moisture resistance improves, but the manufacturing complexity and material consumption increase
Solution Approach 1:
Instead of uniformly increasing partition thickness throughout, the invention applies protective films specifically at the end portions of the organic EL layer where moisture ingress is most likely to occur. This localized approach provides effective moisture protection without the need for increased partition thickness, thereby maintaining simplicity while improving reliability
Solution Approach 2:
The protective film serves as a thin, lightweight barrier that provides effective moisture protection without requiring substantial material consumption or complex structural modifications. This approach achieves moisture resistance through a simple, thin-layer solution rather than thick partitions
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 approach suppresses moisture ingress, enhances the reliability and display quality of OLED devices by preventing degradation and reducing leakage currents.
Implementation Method 1
The organic EL layer includes a light-emitting layer which emits light according to voltage between the lower and upper electrodes
Implementation Method 2
the organic EL layer is patterned by etching
Data Source
AI summary
According to one embodiment, a method of manufacturing a display device, a substrate including a pair of partitions and a lower electrode disposed between the pair of partitions is formed. Then, an organic EL layer including a first portion including a pair of end surfaces which cover the lower electrode and are in contact with side surfaces of the pair of partitions, and a second portion located on each of the pair of partitions and spaced apart from the first portion, is formed. Thereafter, the second portion is removed by etching. Further, an upper electrode which covers the first portion is formed.