OLED Encapsulation Cover with Step Structure and Getter
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Solution Overview
Problem
Existing light-emitting devices, particularly OLEDs, face challenges with encapsulation that leads to moisture and oxygen diffusion, causing damage due to weak boundary surfaces and flexibility issues, especially in larger elements, which results in delamination and corrosion under pressure changes.
Innovation Solution
A light-emitting device design featuring a substrate with a light-emitting element sealed between the substrate and a cover, where the cover has a depression containing a getter material and a central support element, reducing cantilevered sections and placing the getter material close to potential penetration paths to delay damage from moisture and oxygen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a flat fixed cover is glued onto the substrate with sealing compound, then the encapsulation is incompressible and insensitive to pressure, but diffusion paths for oxygen and moisture are formed at the boundary surfaces leading to OLED damage
Solution Approach 1:
The cover is divided into a peripheral sealing region and a central active region separated by a step structure. The peripheral region provides sealing and pressure resistance, while the central region is elevated to create a barrier against diffusion paths at the boundary surfaces.
Solution Approach 2:
A step structure is introduced to create a height difference between the peripheral sealing region and the central active region. This vertical dimension prevents moisture and oxygen from traveling along the boundary surface, blocking the diffusion path while maintaining pressure resistance.
2Area of stationary object
If the light-emitting element is made large in area, then the device can be scaled as desired, but the element becomes flexible with thin material layers which endangers the bond strength and leads to corrosion or damage
Solution Approach 1:
The cover design provides localized reinforcement at the peripheral sealing region through the step structure, which creates a mechanical interlock with the sealing compound. This local structural enhancement prevents delamination at the critical boundary areas while allowing the overall device area to be scaled.
3Object-affected harmful factors
If a cover with recess is used to cover the light-emitting element without contact, then the edges are better protected from diffusion paths, but the self-supporting cover becomes sensitive to compression and mechanical pressure as area increases
Solution Approach 1:
The cover structure is segmented into a peripheral sealing region that contacts the substrate and a central active region that is elevated. This segmentation allows the peripheral region to provide mechanical support and pressure resistance, while the central region remains separated to block diffusion paths.
Solution Approach 2:
The step structure creates a vertical separation between the central active region and the substrate, providing protection from diffusion paths without requiring the entire cover to be non-contacting. The peripheral region maintains contact for mechanical stability under compression.
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 design allows for scalable light-emitting devices with enhanced protection against moisture and oxygen, reducing the risk of damage and delamination, while maintaining mechanical stability and preventing corrosion, even under varying environmental conditions.
Implementation Method 1
a getter material, which is suitable for absorbing or binding oxygen and/or moisture, can be arranged on the inside of the cover at a distance from the light-emitting element
Data Source
Figure 1~4
Figure 5~7
AI summary
The device has a substrate (SU) and a light-emitting element (LE) that is flatly placed on the substrate. The light-emitting element is tightly enclosed in a covering (AD) between the substrate and the covering. A recess (V) is provided in the covering and is opened towards the light emitting element and forms a hollow space along with the light emitting element. A getter material (GE) is arranged in the covering that has a support member (SE). The covering supports on the light emitting element in a supporting area (AB) that is away from a peripheral section.