Local Glass Seals for Flexible OLED Encapsulation
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Solution Overview
Problem
Current encapsulation technologies for flexible electroluminescent devices, particularly OLEDs, face challenges in providing effective protection against moisture and oxygen due to high permeability of polymer materials and the complexity of thin film layer deposition, while traditional encapsulation substrates are rigid and unsuitable for roll-to-roll manufacturing.
Innovation Solution
The implementation of local glass seals under individual or groups of light-emitting elements, which are formed using a glass material with low permeation rates for moisture and oxygen, and can be integrated with a thin film encapsulation structure to enhance protection against pinhole defects and secondary paths of moisture or oxygen ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If polymer encapsulation materials are used for flexible electroluminescent devices, then flexibility is maintained, but protection against moisture and oxygen is insufficient due to high permeability
Solution Approach 1:
The patent combines flexible polymer substrates with rigid glass seal structures to create a composite encapsulation system. The flexible substrate maintains device bendability while the glass seals provide hermetic barriers against moisture and oxygen, resolving the contradiction between flexibility and protection.
Solution Approach 2:
Instead of using a complete rigid encapsulation substrate that would eliminate flexibility, the patent segments the encapsulation into localized glass seals positioned only where electro-optical elements are present. This segmentation allows the majority of the substrate to remain flexible while providing protection at critical locations.
2Reliability
If traditional encapsulation substrates are used, then protection against moisture and oxygen is improved, but flexibility is lost due to rigidity
Solution Approach 1:
The patent applies rigid glass seal structures only in local areas where electro-optical elements require protection, rather than using a uniformly rigid substrate. This local application of rigidity provides necessary protection while maintaining overall substrate flexibility in regions without elements.
3Reliability
If thin film encapsulation structure is added to enhance protection, then protection against pinhole defects is improved, but device complexity increases
Solution Approach 1:
The patent forms glass seals on the substrate before depositing thin film encapsulation layers. This preliminary action creates a robust first line of defense against moisture and oxygen ingress, allowing subsequent thin film layers to provide additional protection with reduced complexity concerns.
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 provides effective protection for electroluminescent devices by reducing moisture and oxygen ingress, maintaining flexibility, and integrating with existing thin film encapsulation to enhance the longevity and performance of the devices.
Implementation Method 1
glass material with low permeation rates for moisture and oxygen
Data Source
AI summary
An electroluminescent display or lighting product incorporates a panel including a collection of distinct light-emitting elements formed on a substrate. A plurality of distinct local seals are formed below respective individual light-emitting elements or groups of light-emitting elements. Some embodiments combine a metal foil substrate and glass local seals in a flexible bottom-emitting product. The local seal may be used in conjunction with a continuous thin film encapsulation structure. Optical functions can be provided by each local seal, including refraction, filtering, color shifting, and scattering. Each local seal is formed by depositing a low melting temperature glass powder suspension or paste using inkjet technology, and fusing the glass powder using a scanning laser beam having a tailored beam profile. In other embodiments, a lower encapsulation substrate incorporating local window seals is wholly or partially pre-formed.