OLED Pixel Defining Layer Inclined Surface Organic Thickness Control
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Solution Overview
Problem
Existing organic light emitting display panels face challenges in uniform organic layer thickness and precise layer formation, leading to potential differences in emission efficiency across pixel regions due to the use of masks in deposition processes.
Innovation Solution
The proposed solution involves an organic light emitting display panel design with a substrate, an OLED, and an encapsulation member, where the OLED features a first electrode, a pixel defining layer with both flat and inclined surfaces, and an organic layer with a thickness reduction in the inclined region, allowing for precise organic layer formation without masks using a fluorine-containing photoresist and solvent process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mask is used in the deposition process to form the organic layer, then the organic layer can be formed with defined patterns, but the thickness uniformity and positioning precision deteriorate due to mask alignment issues and shadow effects
Solution Approach 1:
The patent removes the mask from the deposition process entirely. Instead of using a mask to define the organic layer pattern, the pixel defining layer with its inclined surface serves as the structural guide for organic layer formation, eliminating mask-related alignment and thickness uniformity issues
Solution Approach 2:
The pixel defining layer's inclined surface automatically guides the organic layer deposition process. The organic layer naturally conforms to the inclined surface geometry during deposition, enabling self-aligned pattern formation without external masking tools
2Ease of manufacture
If the organic layer is formed with uniform thickness across all regions, then manufacturing is simplified, but emission efficiency varies across pixel regions due to differences in electrode exposure and layer geometry
Solution Approach 1:
The patent creates different organic layer thicknesses in different regions. The organic layer has a first thickness in the first region and a second thickness in the second region, with the second thickness being greater than the first. This local variation compensates for geometric differences and ensures uniform emission efficiency across pixel regions
Data Source
AI summary
An organic light emitting display panel and associated methods, the panel including a substrate; an organic light emitting diode (OLED) on the substrate; and an encapsulation member to separate the OLED from an external environment, wherein the OLED includes a first electrode on the substrate; a pixel defining layer exposing the first electrode and including a flat planar surface and an inclined planar surface extending from the flat planar surface such that the inclined planar surface overlaps an edge of the first electrode; an organic layer, the organic layer including a first region on the first electrode and a second region on the inclined planar surface; and a second electrode on the organic layer, and wherein, in the second region, a thickness of the organic layer is decreased along a direction extending away from the first region.