OLED Bus Electrode IR Drop Reduction via Segmented Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting display apparatuses often experience IR drop and unintended brightness differences due to the absence of a bus electrode, leading to manufacturing inefficiencies and reduced luminous stability.
Innovation Solution
The solution involves forming a pixel electrode and a bus electrode on the same layer, with a first intermediate layer and an emission layer in between, and creating openings in these layers to allow the opposite electrode to contact the bus electrode directly, thereby minimizing IR drop and ensuring uniform brightness across pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the opposite electrode is formed integral to all pixels without bus electrode, then the manufacturing process is simple, but IR drop occurs and brightness uniformity deteriorates
Solution Approach 1:
The electrode system is segmented into pixel electrodes for individual pixel control and a separate bus electrode for power distribution. This segmentation allows the bus electrode to be strategically positioned to minimize IR drop while maintaining manufacturing simplicity through the use of intermediate layers with openings that facilitate direct contact between the opposite electrode and bus electrode.
Solution Approach 2:
Intermediate layers with openings are introduced as mediators to enable direct contact between the opposite electrode and bus electrode. These intermediate layers serve as a bridge that maintains the simple integral formation process while creating localized contact points that eliminate IR drop and ensure brightness uniformity across all pixels.
2Reliability
If bus electrode is added to prevent IR drop, then brightness uniformity improves, but device complexity increases
Solution Approach 1:
The bus electrode is merged with the pixel electrode formation process by forming both on the same substrate using the same integral electrode formation step. This merging approach adds the bus electrode functionality without requiring separate complex manufacturing processes, thus improving brightness uniformity while minimizing device complexity.
Solution Approach 2:
The intermediate layer serves multiple functions: it provides electrical insulation between different electrode components, maintains structural integrity, and creates controlled openings for electrical contact. This multi-functionality reduces the need for additional components, thereby improving brightness uniformity without proportionally increasing device complexity.
3Reliability
If intermediate layers with openings are formed, then direct contact between opposite electrode and bus electrode is achieved, but manufacturing precision requirements increase
Solution Approach 1:
The intermediate layers with openings are formed in advance during the electrode formation process, before the opposite electrode is deposited. This preliminary action ensures that the openings are pre-positioned with high precision, and subsequent electrode formation simply follows these predetermined pathways, thereby achieving reliable electrical contact without excessively high manufacturing precision requirements.
Solution Approach 2:
The formation of openings in intermediate layers replaces complex mechanical alignment processes. By using deposition and etching techniques to create the openings, the system achieves precise alignment through material removal and deposition control rather than mechanical positioning, thereby improving electrical contact reliability while managing manufacturing precision requirements.
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 configuration enhances manufacturing efficiency and achieves high luminous stability by preventing IR drop and brightness differences, allowing for improved electrical conductivity and uniform light emission across the display.
Implementation Method 1
forming a first opening by removing a portion of the first intermediate layer on the bus electrode so that at least a part of the bus electrode is exposed
Data Source
AI summary
An organic light emitting display apparatus and a method of manufacturing the same are disclosed. The organic light emitting display apparatus includes, for example, a pixel electrode and a bus electrode spaced apart and electrically insulated from each other, a pixel defining layer exposing a part of the pixel electrode including a central part thereof and a part of the bus electrode, a first intermediate layer on a top surface of the pixel defining layer between the pixel electrode and the bus electrode, the first intermediate layer having a first opening in a part of the bus electrode to expose a part of the bus electrode, an emission layer disposed on the first intermediate layer, and an opposite electrode disposed on the emission layer to correspond to the pixel electrode and the bus electrode and contacting the bus electrode through the first opening of the first intermediate layer.