OLED Panel Via Hole Undercut Structure for Encapsulation
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Solution Overview
Problem
Organic light-emitting display panels face failure due to direct exposure of the organic light emitting layer when via holes are formed to accommodate additional functional devices, leading to susceptibility to water and oxygen, which affects the display effect.
Innovation Solution
A method involving a substrate with a non-display area and display area, forming a barrier layer and pixel circuit where the barrier layer is patterned to create an undercut structure, allowing the light emitting layer to be disconnected at the side wall, and a continuous thin film encapsulation layer is applied to cover the light emitting layer and undercut structure, preventing exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If via holes are formed in the display area to accommodate functional devices, then the functionality of the display device is improved, but the organic light emitting layer is directly exposed to water and oxygen, causing panel failure
Solution Approach 1:
The invention transitions from a two-dimensional planar structure to a three-dimensional undercut structure by etching the substrate vertically. The via holes are formed with lateral etching that creates an undercut profile, allowing the light emitting layer to be positioned within the undercut region rather than directly exposed at the surface. This dimensional change enables both via hole functionality and light emitting layer protection to coexist.
Solution Approach 2:
The light emitting layer is nested within the undercut structure formed by the via hole etching. The organic light emitting layer is positioned inside the laterally etched region, surrounded by the inorganic encapsulation layer and barrier layer, creating a nested configuration where the light emitting layer is protected within the multi-layer structure rather than being exposed at the surface.
2Stability of the object's composition
If the light emitting layer is continuously formed across the substrate, then the display uniformity is improved, but water and oxygen can invade through via holes and affect the light emitting layer
Solution Approach 1:
The encapsulation strategy moves from a simple planar overlay to a three-dimensional undercut configuration. The inorganic encapsulation layer and barrier layer extend laterally beneath the light emitting layer, creating an undercut profile that provides lateral protection against water and oxygen invasion while maintaining continuous coverage over the display area.
Solution Approach 2:
The inorganic encapsulation layer and barrier layer are formed beforehand to create a protective undercut structure before the light emitting layer is deposited. This pre-formed protective structure cushions the light emitting layer against water and oxygen invasion through via holes, preventing harmful factors from reaching the organic material.
3Adaptability or versatility
If via holes are formed to accommodate functional devices, then device integration is improved, but the organic light emitting layer becomes susceptible to environmental degradation
Solution Approach 1:
The via hole structure is transformed from a simple vertical penetration to a three-dimensional undercut configuration with lateral etching. This dimensional change allows the light emitting layer to be positioned within the protected undercut region, enabling device integration through via holes while preventing environmental degradation of the organic material.
Solution Approach 2:
The light emitting layer is nested within the multi-layer encapsulation structure created by the undercut via holes. The organic light emitting layer is surrounded by inorganic encapsulation layer and barrier layer within the undercut region, creating a nested protective configuration that extends service life while accommodating functional devices.
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 solution effectively prevents water and oxygen invasion, prolonging the service life of the organic light-emitting display panel by ensuring the light emitting layer is encapsulated, even when via holes are formed for functional devices.
Implementation Method 1
patterning the substrate by using the barrier layer as a mask in the non-display area to form a groove; where the groove is in a position, corresponding to the via hole, of the substrate
Implementation Method 2
forming the light emitting layer on the pixel circuit by an evaporation method
Implementation Method 3
forming the first inorganic layer on the light emitting layer by a vapor deposition method; forming the second inorganic layer on the organic layer by the vapor deposition method
Data Source
AI summary
The present disclosure provides an organic light-emitting display panel, a method for preparing the same and a display device. The method includes: providing a substrate, where the substrate includes a non-display area and a display area surrounding the non-display area; forming a barrier layer and a pixel circuit on the substrate, where an orthographic projection of the pixel circuit on the substrate and an orthographic projection of the non-display area on the substrate do not overlap; patterning the barrier layer in the non-display area to form at least one via hole penetrating the barrier layer; patterning the substrate by using the barrier layer as a mask in the non-display area to form a groove; forming a light emitting layer on the pixel circuit; and forming a thin film encapsulation layer covering the light emitting layer and the side wall of the draw-in structure on the light emitting layer.