OLED Package Structure with Segmented Inorganic Layers
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Solution Overview
Problem
Flexible OLEDs with inorganic thin film packages face issues of stress-induced cracking and peeling due to poor bendability, leading to large-area failures when curled or folded.
Innovation Solution
The OLED package structure and method involve a layered structure with inorganic materials, where the first and second package layers have non-uniform thicknesses, with the thicker regions adjacent to thinner regions, and an organic layer in between to buffer and absorb stress, reducing crack occurrence and enhancing water and oxygen resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an inorganic thin film layer is used in the OLED package structure, then water and oxygen resistance is improved, but bendability deteriorates leading to cracking and peeling when curled or folded
Solution Approach 1:
The inorganic thin film layer is divided into multiple segments (first inorganic thin film layer, second inorganic thin film layer, third inorganic thin film layer) separated by organic buffer layers. This segmentation allows each layer to independently manage stress, preventing crack propagation while maintaining water and oxygen barrier functionality.
Solution Approach 2:
Organic buffer layers are introduced as intermediary layers between the inorganic thin film layers. These buffer layers absorb and distribute mechanical stress during bending, preventing direct stress transmission between rigid inorganic layers, thereby eliminating cracking and peeling while preserving the protective function.
2Manufacturing precision
If the inorganic thin film layer is made compact to improve barrier performance, then deposition quality is improved, but internal stress increases leading to cracking
Solution Approach 1:
The compact inorganic thin film layer is segmented into multiple thinner layers separated by organic buffer layers. Each thin inorganic layer maintains high deposition quality and compactness, while the organic buffer layers between them accommodate and distribute internal stress, preventing stress concentration and crack formation.
Solution Approach 2:
The film thickness parameter of inorganic layers is changed from a single thick layer to multiple thin layers. This parameter modification reduces the internal stress within each individual inorganic layer while maintaining the overall barrier performance through the stacked structure.
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 approach effectively decreases thin film stress, reduces cracking and peeling risks, and enhances the water and oxygen resistance capabilities of the OLED package, while promoting deposition quality and preventing serious abnormalities.
Implementation Method 1
the first organic layer and the second organic layer are respectively used for buffering and absorbing the stress of the first inorganic thin film layer and the second inorganic thin film layer
Implementation Method 2
both the first package layer and the second package layer are manufactured with an inorganic material... enhances the water and oxygen resistance capabilities
Data Source
AI summary
The present application provides an OLED package structure, comprises a package unit and a flexible substrate deposited with an OLED element; the package unit comprises a first package layer, a first inorganic layer and a second package layer, which sequentially stack up on the OLED element; the first package layer comprises a first pixel region and a first pixel define region, and the film thickness of the first pixel define region gradually decreases from an edge to an interior of the first pixel define region; the second package layer comprises a second pixel region corresponding to the first pixel region and a second pixel define region corresponding to the first pixel define region, and the film thickness of the second pixel region gradually decreases from an edge to an interior of the second pixel region. The present application further provides an OLED package method.