Inkjet-Printed OLED Spacer Fixation via Segmented Planarization
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Solution Overview
Problem
In the fabrication of organic light-emitting display panels using the inkjet printing process, the insulating material used causes poor adhesion or ineffective fixation of spacers, leading to increased production costs due to the need for additional alignment marks and processes to improve bonding.
Innovation Solution
The use of a planarization layer with ink-repellent material that covers the spacer region but exposes the emission region, along with a position-retention element electrically insulated from the bottom electrode, allows for effective fixation of spacers on the array substrate, preventing them from detaching and reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If inkjet printing process is used to form organic light-emitting materials, then manufacturing precision and material profile are improved, but adhesion of spacers deteriorates due to the insulating material used
Solution Approach 1:
The planarization layer is segmented into different functional regions: a first region covering the spacer area with good adhesion properties, and a second region in the emission area with ink-repellent properties. This segmentation allows each region to fulfill its specific function without compromising the other.
Solution Approach 2:
Different regions of the planarization layer are assigned different material properties: the spacer region uses materials with good adhesion (e.g., organic photoresist, acrylic resin) while the emission region uses ink-repellent materials. This local differentiation resolves the contradiction between spacer adhesion and material profile.
2Reliability
If additional alignment marks and processes are added to improve spacer bonding, then spacer adhesion is improved, but device complexity and production cost increase
Solution Approach 1:
The planarization layer itself provides the adhesion function through its dual-region design. The spacer region's material properties enable self-adhesion of spacers without requiring additional alignment marks or external bonding processes, thereby reducing complexity.
3Manufacturing precision
If insulating material is used in inkjet printing process, then emission region definition is improved, but spacer fixation effectiveness deteriorates
Solution Approach 1:
The planarization layer is divided into functional segments: the emission region uses insulating ink-repellent material for precise definition, while the spacer region uses adhesion-promoting materials. This segmentation resolves the conflict between emission definition and spacer fixation.
Solution Approach 2:
The planarization layer serves multiple functions simultaneously: it provides emission region definition through ink-repellent properties, ensures spacer adhesion through adhesion-promoting materials in the spacer region, and maintains planarity for subsequent layers. This multi-functionality eliminates the need for separate dedicated structures.
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 design enhances the yield of organic light-emitting display panels by ensuring stable attachment of spacers and eliminating the need for additional alignment processes, thereby reducing production costs and improving the profile of the organic light-emitting material layers.
Implementation Method 1
the planarization layer includes ink-repellent material
Data Source
AI summary
An organic light-emitting display panel and a fabrication method thereof include using an inkjet printing process to form the organic emission material of the display panel and providing a specific design of the relative position of the spacer and the planarization layer with ink-repellent material such that the spacer can be effectively fixed on the array substrate without falling from the planarization layer.