Flexible OLED Partition Wall Crack Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic electroluminescent devices face issues with moisture infiltration due to inefficient barrier capabilities of the press sensitive adhesive, leading to higher probability of moisture permeation through lateral surfaces, especially when cracks are generated during the manufacturing process, which can result in non-light-emitting regions and reliability failures.
Innovation Solution
A flexible organic electroluminescent device is designed with a partition wall pattern in an inverse taper shape in the non-display area to surround the display area, separating passivation layers to prevent crack propagation and moisture infiltration, using layers with different etch rates to ensure the passivation layers on the partition wall are distinct from those on the substrate, thereby blocking external shocks and maintaining panel reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If press sensitive adhesive is used to encapsulate the substrate, then the device structure is simplified and ease of manufacture is improved, but moisture infiltration probability increases due to insufficient barrier capability
Solution Approach 1:
The encapsulation structure is segmented into multiple functional layers: press sensitive adhesive layer, barrier film, and partition wall pattern. This segmentation allows each layer to perform its specific function - the adhesive provides bonding, the barrier film provides moisture protection, and the partition walls provide structural support and additional barrier function, collectively resolving the contradiction between ease of manufacture and moisture infiltration prevention
Solution Approach 2:
The encapsulation system uses composite material structure combining press sensitive adhesive with barrier film and partition wall patterns. This composite approach leverages the bonding capability of adhesive materials while incorporating the moisture-blocking properties of barrier films and the structural integrity of partition walls, achieving both ease of manufacture and high reliability
2Ease of manufacture
If passivation layers are formed continuously across the substrate and partition wall, then manufacturing process is simplified, but crack propagation is facilitated leading to moisture infiltration
Solution Approach 1:
The passivation layer structure is segmented into two distinct parts: a first passivation layer on the substrate and a second passivation layer on the partition wall pattern. This segmentation creates a discontinuity that interrupts crack propagation paths, preventing cracks from spreading from the substrate to the display area while maintaining manufacturing simplicity through a straightforward formation process
Solution Approach 2:
The partition wall pattern acts as an intermediary structure between the substrate and the display area. By forming passivation layers on both the substrate and the partition wall pattern separately, the partition wall serves as a mediator that blocks crack propagation while maintaining the continuity of protection, thus resolving the contradiction between manufacturing simplicity and crack resistance
3Ease of manufacture
If the partition wall pattern is formed with the same etch rate as the substrate, then the formation process is simplified, but the passivation layers cannot be effectively separated
Solution Approach 1:
The partition wall pattern is designed with local quality differentiation - having a different etch rate compared to the substrate. This local difference in etch rate enables selective formation of passivation layers, allowing the first passivation layer on the substrate and the second passivation layer on the partition wall to be formed separately with precise control, thus achieving both formation simplicity and separation precision
Data Source
AI summary
Provided is a flexible organic electroluminescent device and a method for fabricating the same. The device includes a switching thin film transistor and a drive thin film transistor formed at an each pixel region on the substrate; an interlayer insulating layer formed on the substrate; a partition wall pattern formed in the non-display area of the substrate; a first electrode formed on the interlayer insulating layer; a bank formed around each pixel region; an organic light emitting layer separately formed on the first electrode; a second electrode formed on an entire surface of the display area; a first passivation layer formed on an entire surface of the substrate; an organic layer and a second passivation layer formed on the first passivation layer of the display area; a barrier film located to face the substrate.