OLED Display Edge Sealing With Nested Dams Against Impurity Ingress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic EL display devices face deterioration due to impurity reactions with the active species in the light-emitting elements, leading to reduced efficiency and lifetime, particularly at the edge portions of the substrate where impurities like water and oxygen can easily enter.
Innovation Solution
A display device structure featuring a substrate with a display region and peripheral region, including a passivation film with inorganic and organic layers, a resin layer, and dams to prevent impurity entry, along with auxiliary wiring and partition walls that cover edge portions to protect the light-emitting elements and maintain electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shielding region is formed to block impurities at the edge portion of the substrate, then reliability of the display device is improved, but device complexity increases due to additional structural elements
Solution Approach 1:
The patent implements a nested dam structure where a first dam is formed within a second dam, creating multiple concentric shielding regions. The first dam is positioned closer to the display region while the second dam surrounds it, forming a nested configuration that enhances impurity blocking capability through multiple layered barriers without requiring completely separate structural systems.
Solution Approach 2:
The shielding structure is divided into multiple segmented components: the first dam with selective passivation film coverage, the second dam surrounding it, and the resin layer filling gaps between them. This segmentation allows each component to perform specific functions (impurity blocking, selective protection, gap sealing) and simplifies the manufacturing process by enabling step-by-step formation of each element.
2Duration of action of stationary object
If multiple protective layers (passivation film and resin layer) are added to prevent impurity entry, then lifetime of the light-emitting element is extended, but manufacturing precision requirements increase
Solution Approach 1:
The passivation film is selectively formed only on specific portions of the first dam that are in contact with or adjacent to the light-emitting element, rather than covering the entire dam structure. This localized protection approach applies the protective inorganic compound layer precisely where impurity blocking is most critical, reducing unnecessary material deposition and simplifying the manufacturing process by eliminating the need to pattern and deposit protective layers on all dam surfaces.
Solution Approach 2:
The resin layer serves as an intermediary material that fills the gap between the first and second dams and provides additional impurity blocking functionality. This resin-based intermediate layer is easier to manufacture than inorganic protective layers, as it can be deposited using spin coating or dispensing methods, and it effectively seals potential impurity pathways without requiring high-precision patterning or high-temperature processing.
3Object-affected harmful factors
If dams and partition walls are used to cover edge portions of auxiliary wiring, then oxidation of the light-emitting element is prevented, but area of the display region is reduced
Solution Approach 1:
The partition wall covers not only the edge portions of the light-emitting element but also extends to cover edge portions of the auxiliary wiring in the peripheral region. This partial extension beyond the strictly necessary area provides excessive protection against oxidation for the auxiliary wiring, preventing potential corrosion or degradation of electrical connections without significantly impacting the display region area, as the auxiliary wiring is located in the peripheral region.
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
The solution effectively prevents impurity entry and oxidation, enhancing the reliability and longevity of the display device by maintaining the integrity of the light-emitting elements and ensuring consistent performance.
Implementation Method 1
forming a region (shielding region) for blocking impurities between a display region including light-emitting elements and a peripheral region surrounding the display region
Implementation Method 2
An organic EL (Electroluminescence) display device has been known as a typical example of a display device
Implementation Method 3
the organic compound is oxidized or reduced to exist in a charged state which further undergoes recombination to generate an excited state
Implementation Method 4
the organic compound is oxidized or reduced to exist in a charged state which further undergoes recombination to generate an excited state
Data Source
AI summary
Disclosed is a display device possessing: a substrate having a display region and a peripheral region surrounding the display region; a pixel over the display region; a passivation film over the pixel; a resin layer over the passivation film; a first dam over the peripheral region and surrounding the display region; and a second dam surrounding the first dam. The passivation film includes; a first layer containing an inorganic compound; a second layer over the first layer, the second layer containing an organic compound; and a third layer over the second layer, the third layer containing an inorganic compound. The second layer is selectively arranged in a region surrounded by the first dam. The resin layer is selectively arranged in a region surrounded by the second dam.