Flared OVJP Delivery Channels for Uniform OLED Thickness
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Solution Overview
Problem
Existing organic vapor jet printing (OVJP) systems face challenges in achieving uniform thickness and efficiency in depositing organic materials for organic light-emitting diodes (OLEDs), particularly due to non-uniform deposition profiles and inefficiencies in material distribution.
Innovation Solution
The use of a nozzle block with diverging delivery apertures and offset exhaust apertures, featuring a flared delivery channel design, which improves uniformity and deposition efficiency by redirecting organic vapor flux towards the centerline, optimizing the deposition profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional OVJP systems use straight delivery channels, then the system structure is simple, but the deposition profile shows central depressions and poor thickness uniformity
Solution Approach 1:
The delivery channel is designed with a curved or flared geometry instead of a straight channel. The channel curves upward toward the centerline as it approaches the delivery aperture, causing the organic vapor jet to redirect toward the centerline. This curved path corrects the deposition profile by filling in central depressions and improving thickness uniformity across the substrate.
Solution Approach 2:
The delivery channel has non-uniform cross-sectional dimensions along its length, with the aperture width and height varying to control vapor flow direction. The channel geometry is locally optimized at different positions: narrower at the source and flared near the aperture to redirect the jet. This local variation in channel properties achieves uniform deposition without requiring complex external adjustment mechanisms.
2Productivity
If the delivery aperture is positioned closer to exhaust apertures, then material distribution efficiency improves, but thickness uniformity across the substrate deteriorates
Solution Approach 1:
The curved delivery channel compensates for the close positioning of the delivery aperture to exhaust apertures by redirecting the vapor jet upward toward the centerline. This curvature ensures that even though the aperture is close to exhaust structures, the deposited material is distributed uniformly across the substrate rather than concentrating in specific regions.
3Ease of manufacture
If organic vapor jet printing is used for OLED fabrication, then cost and flexibility improve, but deposition uniformity and efficiency are insufficient
Solution Approach 1:
The curved delivery channel is integrated into the OVJP system to correct deposition uniformity issues. This geometric modification maintains the cost-effective and flexible nature of organic material processing while achieving the deposition uniformity required for high-quality OLED fabrication. The solution avoids complex additional equipment by using simple geometric optimization of the existing vapor delivery path.
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
Enhances thickness uniformity and deposition rates by reducing central depressions and convexities, achieving higher uniformity and efficiency in organic material deposition for OLEDs.
Implementation Method 1
a first delivery channel having a first end that forms a first delivery aperture disposed between the first exhaust aperture and the second exhaust aperture
Implementation Method 2
the first delivery channel is wider at a first portion than at a second portion, the first portion being closer to the delivery aperture that the second portion
Data Source
AI summary
Devices for deposition of material via organic vapor jet printing (OVJP) and similar techniques are provided. The depositor includes delivery channels ending in delivery apertures, where the delivery channels are flared as they approach the delivery apertures, and/or have a trapezoidal shape. The depositors are suitable for fabricating OLEDs and OLED components and similar devices.