OLED Pixel Separator Structure for Precise Inkjet Emission Layers
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Solution Overview
Problem
Current organic light emitting display devices face challenges in achieving high-resolution and efficient manufacturing processes, particularly in forming the light emitting layer and maintaining hydrophobic characteristics of the pixel defining layer, which affects the accuracy and proximity of light emitting layers in display devices.
Innovation Solution
The proposed solution involves a light emitting display device structure with a separator having a protruding second layer and a first layer, where the second layer is an inorganic insulating layer and the first layer is an organic insulating layer, allowing for precise formation of the light emitting layer using an inkjet method and maintaining hydrophobic characteristics to ensure accurate placement and close proximity of light emitting layers, thereby enhancing resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional single-layer separator structure is used, then the manufacturing process is simpler, but the precision of light emitting layer formation and hydrophobic characteristics are compromised
Solution Approach 1:
The separator is divided into two distinct layers: a first layer (layer 1) and a second layer (layer 2). The first layer provides the hydrophobic surface for precise light emitting layer formation, while the second layer provides structural support. This segmentation allows each layer to be optimized for its specific function, achieving high manufacturing precision without requiring the entire separator structure to be complex.
Solution Approach 2:
The first layer of the separator is specifically designed with hydrophobic characteristics to enable precise light emitting layer formation through inkjet printing. The second layer is designed with different properties for structural stability. This local quality differentiation allows the separator to provide both the precise local surface properties needed for manufacturing and the overall structural integrity required for device operation.
2Manufacturing precision
If light emitting layers are placed closer together to increase resolution, then display resolution improves, but maintaining hydrophobic characteristics and preventing material mixing becomes difficult
Solution Approach 1:
The two-layer separator structure creates distinct functional zones: the first layer maintains hydrophobic characteristics for material repulsion and precise positioning, while the second layer provides structural separation. This segmentation enables light emitting layers to be placed closer together while maintaining reliable hydrophobic barriers that prevent material mixing.
Solution Approach 2:
The separator combines two different materials with complementary properties: the first layer uses a material with strong hydrophobic characteristics for surface interaction control, while the second layer uses a material optimized for mechanical strength and structural stability. This composite structure maintains reliability even when layers are closely spaced.
3Productivity
If an inkjet method is used for light emitting layer formation, then manufacturing efficiency and resolution improve, but the hydrophobic characteristics of the pixel defining layer must be precisely maintained
Solution Approach 1:
The separator's first layer is specifically engineered to provide consistent hydrophobic characteristics that work optimally with inkjet printing processes. This dedicated hydrophobic layer ensures that inkjet-deposited light emitting materials are properly repelled and positioned, maintaining manufacturing precision while enabling high productivity through automated inkjet fabrication.
4Manufacturing precision
If the separator layers are formed with different widths, then the protruding structure enables better light emitting layer positioning, but the manufacturing process becomes more complex
Solution Approach 1:
The solution transitions from controlling only the horizontal width dimension to utilizing the vertical stacking dimension. By forming the first and second layers with different widths in the horizontal dimension and stacking them in the vertical dimension, the patent creates a protruding structure that provides precise positioning references for light emitting layers while maintaining manufacturability through standard thin-film deposition techniques.
Data Source
AI summary
A light emitting display device, includes: a substrate; a driving element layer on the substrate and including a transistor and a planarization layer covering the transistor; a cathode and an anode connection electrode on the planarization layer; a separator on the planarization layer and including a first layer and a second layer, wherein the second layer protrudes from the first layer of the separator; a pixel defining layer including a first pixel defining layer on the separator and a second pixel defining layer superimposed with a portion of the cathode and a portion of the anode connection electrode; a light emitting layer on top of the cathode; and an anode connecting electrode, the second pixel defining layer, and an anode above the light emitting layer.