Rollable OLED Encapsulation with Single-Layer Barrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional OLED devices face challenges in providing an effective flexible permeation barrier that can withstand moisture, oxygen, and mechanical damage, especially when rolled, as multi-layer encapsulation often results in internal stresses and delamination issues due to differing mechanical properties and coefficients of expansion.
Innovation Solution
A rollable OLED device is developed with a single layer barrier coated on a plastic lid, which includes an optional hardcoat, providing both permeation and mechanical protection. The barrier and OLED can be fabricated separately and assembled later, using a laminated process to ensure protection and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multi-layer encapsulation is used to protect OLED, then permeation barrier performance is improved, but internal stresses and delamination occur due to differing mechanical properties
Solution Approach 1:
The encapsulation structure is divided into two independent parts: a thin-film encapsulation layer (TFE) providing permeation barrier and a separate flexible lid providing mechanical protection. This segmentation allows each layer to perform its specialized function without interfering with the other, eliminating the delamination problem caused by multi-layer integration.
Solution Approach 2:
An adhesive layer is introduced as an intermediary between the TFE and the flexible lid to ensure strong bonding. This mediator resolves the compatibility issue between materials with different mechanical properties, preventing delamination while maintaining the benefits of both layers.
2Reliability
If rigid barrier layers are used to protect OLED, then permeation protection is improved, but flexibility and rollability are reduced
Solution Approach 1:
The patent uses a thin-film encapsulation structure that is inherently flexible and can be conformally deposited on curved surfaces. This thin-film approach provides effective permeation barrier while maintaining the flexibility needed for rollable displays, replacing traditional rigid glass or metal barriers.
Solution Approach 2:
The encapsulation system combines organic and inorganic materials in a composite thin-film structure, leveraging the advantages of both material types to achieve both barrier performance and flexibility that neither material could provide alone.
3Reliability
If complex multi-layer encapsulation is implemented, then protection performance is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The encapsulation function is segmented into two independent components (TFE and flexible lid) that can be manufactured separately using different processes and then assembled. This reduces manufacturing complexity by allowing each component to be optimized independently and simplifies the overall assembly process.
4Adaptability or versatility
If thin encapsulation layers are used to maintain flexibility, then rollability is improved, but protection against mechanical damage is reduced
Solution Approach 1:
The thin-film encapsulation layer provides sufficient chemical barrier protection while the separate flexible lid provides mechanical protection. This division allows the thin film to maintain flexibility for rolling while the lid compensates for mechanical strength.
Solution Approach 2:
The combination of thin-film encapsulation and flexible lid creates a composite protective structure where each layer contributes its strengths: the thin film provides barrier properties and the lid provides mechanical strength, achieving both flexibility and protection.
Data Source
AI summary
Provided is an OLED device that is rollable and has a rollable protective covering to protect the OLED when rolled. The rollable protective covering may include a single layer barrier and a plastic lid. The single layer barrier may provide permeation protection to the OLED in the OLED device. The protective covering provides mechanical protection to the OLED device when rolled. The protective covering and the OLED may be fabricated separately and assembled afterwards.