Partition-Free Display Fabrication via Selective Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for fabricating organic electroluminescent (EL) displays face challenges in achieving high pixel aperture ratio, increased resolution, and reduced size due to limitations in the accuracy and durability of metal masks used for forming light-emitting layers, and the need for multiple partitions which occupy significant area and hinder productivity.
Innovation Solution
A method involving the formation of an anode, an EL layer, and a cathode, followed by selective removal of these layers to create light-emitting elements, with a conductive layer that is light-transmitting and electrically connects to the cathodes, eliminating the need for partitions and allowing for improved accuracy and productivity in display fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If partitions are provided between adjacent pixels to prevent electric interference, then display quality is improved, but area occupied by partitions increases, making reduction in size and improvement in pixel aperture ratio difficult
Solution Approach 1:
The invention extracts and eliminates the partition structure from the display device by using a common electrode that extends across the entire pixel array. The common electrode serves both as an electrical reference and as a structural element that replaces the need for physical partitions, thereby preventing electric interference without occupying pixel area.
Solution Approach 2:
The common electrode performs multiple functions: it serves as the cathode for all light-emitting elements, provides electrical reference potential across the display, and acts as a structural element that eliminates the need for partitions. This multi-functionality allows the device to maintain display quality without the area penalty of traditional partitions.
2Ease of manufacture
If a metal mask is used to form the light-emitting layer, then formation process is simplified, but size accuracy is inferior to resist mask, making improvement in pixel aperture ratio and resolution difficult
Solution Approach 1:
The invention extracts and eliminates the metal mask from the fabrication process entirely. By using a solution-processable small molecular material that can be deposited using low-cost techniques such as spin coating or inkjet printing, the device achieves high precision patterning without requiring expensive metal masks or complex vacuum evaporation equipment.
Solution Approach 2:
The invention replaces the mechanical vacuum evaporation process with metal masks with solution-based deposition methods. This substitution enables the use of low-cost, high-precision patterning techniques such as inkjet printing or spin coating with photolithography, achieving better size accuracy and resolution while simplifying the manufacturing process.
3Ease of manufacture
If a metal mask is used for light-emitting layer formation, then process is simplified, but the mask is easily deformed by heat from evaporation source, reducing reliability
Solution Approach 1:
The invention extracts and eliminates the metal mask from the fabrication process. By using solution-processable materials and low-cost deposition techniques such as spin coating or inkjet printing, the process generates minimal heat, eliminating the thermal deformation problem entirely while maintaining ease of manufacture.
Solution Approach 2:
The invention replaces the thermal vacuum evaporation process with solution-based deposition methods. This substitution eliminates the high-temperature environment that causes metal mask deformation, while still achieving precise light-emitting layer formation through controlled solution processing and low-cost patterning techniques.
Data Source
AI summary
A novel method for fabricating a display apparatus is provided. An anode is formed over an insulating layer, an EL layer is formed over the anode, and a cathode is formed over the EL layer. A plurality of light-emitting elements are formed without provision of a partition by selectively removing parts of the anode, the EL layer, and the cathode. A conductive layer having a light-transmitting property is formed to cover the plurality of light-emitting elements. The cathodes of the plurality of light-emitting elements are electrically connected to the conductive layer.