OLED Display Applied-Material Separation Layer Staggered Banks
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Solution Overview
Problem
High-resolution OLED panels face challenges in reducing the pitch between subpixels to prevent color mixture of ink during manufacturing, especially with the trend towards higher resolution, where existing methods like vapor deposition require metal masks and have low material utilization, while printing methods like inkjet struggle with ink separation and uniformity.
Innovation Solution
The OLED display device incorporates an applied-material separation layer with staggered bank positions between subpixel lines, featuring application separation openings that include consecutive subpixels of the same color, allowing for precise inkjet application of organic EL material to prevent color mixture and achieve uniform luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pitch between subpixels is reduced to achieve higher resolution, then the resolution is improved, but the risk of color mixture of ink increases
Solution Approach 1:
The applied-material separation layer is divided into multiple banks that segment the application openings, physically separating the inkjet application regions for different subpixels. This segmentation prevents ink from adjacent subpixels from mixing even when the pitch is reduced, while still allowing high-resolution patterning.
Solution Approach 2:
The applied-material separation layer acts as an intermediary structure between the inkjet nozzles and the substrate. It provides a controlled interface that guides ink deposition into specific application openings while preventing lateral spread and color mixture, enabling reduced pitch without compromising color purity.
2Ease of manufacture
If the vapor deposition method is used to deposit organic EL materials, then the material can be deposited, but the utilization ratio of materials is low and metal masks are required
Solution Approach 1:
The invention extracts and removes the metal masks from the deposition process by using the applied-material separation layer with application openings as a built-in patterning structure. This eliminates the need for separate masking layers and reduces material waste associated with mask fabrication and disposal.
Solution Approach 2:
The applied-material separation layer serves multiple functions simultaneously: it acts as a patterning template, a deposition guide, and a structural element. This self-service approach eliminates the need for additional masking steps and improves material utilization by directing deposition only where needed through the application openings.
3Loss of substance
If the inkjet printing method is used to apply organic EL material, then the material utilization ratio is high and large-area printing is enabled, but color mixture of ink occurs at reduced pitch
Solution Approach 1:
The applied-material separation layer segments the inkjet application regions into discrete application openings, each corresponding to a specific subpixel or group of subpixels. This segmentation maintains the high material utilization of inkjet printing while preventing ink from adjacent subpixels from mixing, even at reduced pitch.
Solution Approach 2:
The applied-material separation layer provides different properties in different regions: the banks provide separation and confinement, while the application openings provide controlled access for ink deposition. This local differentiation of properties enables both high material utilization and prevention of color mixture.
4Device complexity
If conventional inkjet printing is used without staggered banks, then the process is simple, but uneven luminance perception occurs
Solution Approach 1:
The banks are positioned asymmetrically in a staggered pattern rather than being aligned directly above each other. This asymmetric arrangement prevents regular patterns of uneven luminance from forming, distributing the visual impact across the display and reducing perceived non-uniformity while adding minimal complexity to the manufacturing process.
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 solution effectively reduces the perception of uneven luminance and prevents color mixture by using staggered bank positions and high wettability/low wettability layers, enhancing the material utilization and resolution of OLED panels.
Implementation Method 1
using staggered bank positions and high wettability/low wettability layers
Implementation Method 2
The inkjet technology ejects droplets of ink from a nozzle to apply them to a substrate
Data Source
AI summary
An OLED display device includes a substrate, subpixel lines on the substrate and an applied-material separation layer on the substrate. Each of the subpixel lines includes subpixels of the same color disposed along a first axis. The applied-material separation layer has application separation openings. Each of the application separation openings includes subpixels of the same color that are consecutive in one subpixel line. Within each application separation opening, organic light-emitting films of the subpixels of the same color are connected by an organic light-emitting film made of the same material as material of the organic light-emitting films of the subpixels. Banks between application separation openings in each of the subpixel lines are different in position from banks between application separation openings in an adjacent subpixel line when seen along a second axis perpendicular to the first axis.