Organic Light-Emitting Display Bank Layers Dispensing
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Solution Overview
Problem
The complexity and cost of forming a uniform organic light-emitting layer in organic light-emitting display devices are increased due to the thermal deposition process, which requires multiple processes, alignment of metal masks, and large equipment, leading to defects and impracticality for large displays.
Innovation Solution
The organic light-emitting layer is formed by dividing pixel columns into groups and dispensing organic light-emitting material onto each group, allowing it to spread and dry uniformly, simplifying the process and reducing stress, thereby achieving a uniform thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thermal deposition process is used to form organic light-emitting layer, then uniform thickness can be achieved, but fabrication process becomes complicated and costly due to multiple processes and metal mask alignment
Solution Approach 1:
The pixel columns are divided into multiple groups, and the organic light-emitting material is dispensed into each group separately. This segmentation allows the material to spread more uniformly within each smaller group, preventing aggregation and achieving uniform thickness without complex metal mask alignment processes
Solution Approach 2:
The patent replaces the thermal deposition process (which requires metal masks and complex equipment) with a dispensing process. The organic light-emitting material is dispensed in a solution state and then spread by capillary action along the bank layers, eliminating the need for thermal deposition equipment and mask alignment
2Reliability
If thermal deposition process is used, then organic light-emitting layer can be formed, but fabrication cost increases due to large equipment and multiple processes
Solution Approach 1:
The patent substitutes the expensive thermal deposition equipment with a simpler dispensing system. The organic light-emitting material is dispensed as a solution and spreads along the bank layers formed by capillary action, eliminating the need for large thermal deposition equipment and reducing fabrication costs
Solution Approach 2:
The bank layers are designed to guide the organic light-emitting material solution to spread automatically along their surfaces through capillary action. This self-spreading mechanism eliminates the need for additional spreading equipment or complex process control, reducing fabrication costs while ensuring uniform layer formation
3Manufacturing precision
If organic light-emitting material is dispensed without dividing pixel columns, then material aggregation occurs causing non-uniform thickness, but dividing into groups increases process steps
Solution Approach 1:
The pixel columns are divided into multiple groups with bank layers formed between them. The organic light-emitting material is dispensed into each group separately, preventing aggregation that would occur if the entire pixel column was treated as one unit. This segmentation achieves uniform thickness while keeping the process simple
Solution Approach 2:
The formation of bank layers and the division into groups is integrated into the existing pixel structure fabrication process. The bank layers are formed using the same materials and processes as the pixel electrodes, merging the grouping function with the existing manufacturing flow and not adding significant process steps
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 method simplifies the fabrication process, reduces costs, and enables the formation of uniform organic light-emitting layers even in large displays, preventing defects caused by material variation and stress.
Implementation Method 1
subsequent spreading of the organic light-emitting material in each of the groups
Data Source
AI summary
An organic light emitting display device according to an example comprises a substrate; a plurality of first bank layers disposed on the substrate in a first direction and a second direction different from the first direction to define a plurality of pixels; a plurality of second bank layers disposed on the first bank layers in the first direction to partition pixel columns of different colors; and a third bank layer formed in each of the pixel columns in the second direction to divide each of the pixel columns into a plurality of groups each including a plurality of the pixels.