Parallel-Flow OVJP Depositor for High-Resolution OLED Printing
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Solution Overview
Problem
Existing organic vapor jet printing (OVJP) technologies face challenges in achieving high resolution and efficient material utilization for organic light-emitting diodes (OLEDs), particularly due to issues with overspray and the inability to rapidly start and stop printing, leading to non-uniform feature sizes and reduced material efficiency.
Innovation Solution
The use of Parallel Delivery-Confinement (PDC) depositors, which align delivery and exhaust apertures in a specific configuration to ensure parallel gas flows, minimizing overspray and enhancing material utilization by confining the organic vapor deposition, allowing for higher resolution and uniform feature printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional OVJP technologies are used, then printing capability is achieved, but material utilization efficiency is poor due to overspray
Solution Approach 1:
A confinement gas flow is introduced as an intermediary between the delivery gas jet and the substrate/environment. This confinement gas acts as a mediator that confines the delivery gas and organic vapor, preventing overspray while maintaining efficient material deposition. The confinement gas flow is positioned laterally adjacent to the delivery aperture and directs the vapor stream toward the substrate.
Solution Approach 2:
The invention uses gas flows (pneumatics) to control the deposition process. A delivery gas carries organic vapor through a delivery aperture, while a confinement gas flow is introduced to confine this delivery gas. The pneumatic control of gas flows enables precise manipulation of the vapor stream to eliminate overspray and improve material utilization efficiency.
2Manufacturing precision
If conventional OVJP printing is used, then organic films can be deposited, but resolution is limited due to inability to rapidly start and stop printing
Solution Approach 1:
The printing process utilizes periodic action by rapidly starting and stopping the delivery gas flow in a controlled manner. The confinement gas flow continues to confine the vapor stream during these rapid transitions, enabling precise control over when and where material is deposited. This periodic activation allows for high-resolution printing with the ability to rapidly start and stop feature deposition.
3Manufacturing precision
If feature size is reduced for high resolution, then printing precision improves, but feature size uniformity deteriorates
Solution Approach 1:
The invention controls the confinement gas flow rate as a key parameter to maintain feature size uniformity. By optimizing the confinement gas flow rate relative to the delivery gas flow rate, the system maintains stable confinement of the vapor stream even when printing small features. This parameter control ensures that feature sizes remain uniform across different print conditions and locations.
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
PDC depositors achieve improved material utilization efficiency and reduced feature size variability, enabling high-resolution printing of OLEDs with increased operational flexibility and precision, even at varying fly heights.
Implementation Method 1
Parallel Delivery-Confinement (PDC) depositors, which align delivery and exhaust apertures in a specific configuration to ensure parallel gas flows
Implementation Method 2
confining the organic vapor deposition
Implementation Method 3
align delivery and exhaust apertures in a specific configuration to ensure parallel gas flows, minimizing overspray
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
OVJP depositors and techniques for using the same are provided, in which the in-substrate plane velocity of the delivery and confinement flows are both nonzero and parallel to each other across the boundary between the two. These configurations provide improved material utilization efficiency and relaxed fly height tolerances, while achieving acceptable printing resolution and feature uniformity.