OLED Encapsulation Grooves for Adhesive Force
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Solution Overview
Problem
The adhesive force between the insulating layer and the encapsulation member in organic electroluminescence display devices is insufficient, leading to defects and deterioration due to exposure to ambient moisture and oxygen, particularly in top-emitting devices with organic planarization and pixel defining layers.
Innovation Solution
Forming a pixel defining layer with an inorganic layer up to the non-emitting region and creating grooves on the planarization layer to increase the contact area between the inorganic pixel defining layer and the encapsulation member, using an inorganic second insulating layer between the organic first insulating layer and the encapsulation member, and filling these grooves with the second insulating layer to enhance adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an organic planarization layer or pixel defining layer is used in top-emitting OLEDs, then the device structure is simplified and manufacturing is easier, but the adhesive force between the encapsulation member and the lower substrate decreases
Solution Approach 1:
The patent applies composite materials by combining organic and inorganic layers. Specifically, an inorganic layer (such as silicon oxide or silicon nitride) is formed on top of the organic planarization layer or pixel defining layer. This composite structure maintains the ease of manufacture benefits from organic layers while adding the adhesive advantages of inorganic materials, thereby resolving the contradiction between ease of manufacture and adhesive force.
Solution Approach 2:
The patent applies local quality by forming grooves in the organic planarization layer or pixel defining layer at specific locations where the encapsulation member will be attached. These grooves create localized areas of increased surface area and mechanical interlocking, enhancing adhesive force only where needed without affecting the overall ease of manufacture of the device structure.
2Reliability
If grooves are formed in the insulating layer and filled with inorganic material, then the adhesive force and encapsulation capability are improved, but the device complexity and manufacturing steps increase
Solution Approach 1:
The patent applies preliminary action by forming the grooves in the organic planarization layer or pixel defining layer before depositing the inorganic layer. This preliminary structuring allows the inorganic material to be deposited conformally into the grooves, automatically creating the desired adhesive enhancement structure without requiring additional post-processing steps, thereby limiting the increase in device complexity.
3Reliability
If the inorganic layer is formed up to the non-emitting region, then the contact area and adhesive force are increased, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies dimensionality change by extending the inorganic layer from the emitting region into the non-emitting region along the planar surface. This lateral extension into a different spatial dimension (from vertical stacking to horizontal spreading) increases the contact area and adhesive force without requiring extremely precise vertical alignment, thereby managing manufacturing precision requirements.
Data Source
AI summary
Embodiments of an organic electroluminescence display device and methods of fabricating such devices are disclosed. One embodiment of an organic electroluminescence display device comprises a thin film transistor and wirings disposed on a substrate, wherein the substrate has an emitting region and non-emitting region. The display device further comprises a first insulating layer disposed on the substrate in the emitting region and the non-emitting region, a pixel electrode disposed on the first insulating layer, a second insulating layer disposed on the emitting region to partially expose the pixel electrode, a light-emitting layer disposed on the pixel electrode, and an encapsulation member disposed on the second insulating layer on the non-emitting region.