Display Device Metal Layer Slit for Organic EL Positioning
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Solution Overview
Problem
The formation of organic layers in organic electroluminescence (EL) display devices using the ink-jet method is challenging due to the difficulty in accurately positioning the organic layer material, especially when high-reflectivity metals are used, making it hard to confirm the coating position and leading to potential defects in the sealing film.
Innovation Solution
A display device configuration with a flattening film and metal layers where slits are formed to overlap the organic layer's circumferential end edge, allowing the metal layers to contact each other and expose a lower layer, reducing light reflection and enabling accurate confirmation of the organic layer's position, even with high-reflectivity metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-reflectivity metal materials are used for the metal layer, then the electrode and frame wiring line can be formed with good electrical properties, but it becomes difficult to confirm the coating position of the organic layer material due to light reflection
Solution Approach 1:
The patent divides the metal layer into multiple segments: a first metal layer and a second metal layer separated by a slit. This segmentation allows the first metal layer to maintain electrical continuity while the second metal layer region (without organic layer) provides a non-reflective inspection area, thus resolving the contradiction between electrical performance and inspectability.
Solution Approach 2:
The patent applies different properties to different regions of the metal layer structure. The first metal layer uses high-reflectivity material for electrical conductivity, while the second metal layer region is designed to be free of organic layer material to provide light transmission for inspection. This local differentiation allows each region to fulfill its specific function without compromising the other.
2Ease of manufacture
If the organic layer is formed by ink-jet method, then flexible material application is achieved, but the film formation properties are easily affected by the substrate state making it difficult to form the peripheral edge at high accuracy
Solution Approach 1:
The patent creates a slit structure in the metal layer before forming the organic layer. This preliminary action establishes a predefined non-reflective region that serves as a reference for inspection, allowing the organic layer coating process to be monitored and adjusted to achieve better positioning accuracy at the peripheral edge.
Solution Approach 2:
The slit structure provides a visual feedback mechanism during the organic layer formation process. By observing whether the organic layer material properly covers the frame region and reaches the intended peripheral edge position through the non-reflective slit area, the coating process can be monitored and corrected in real-time to improve positioning accuracy.
3Reliability
If the organic layer peripheral edge is positioned in the frame region, then complete coverage is achieved, but it is difficult to confirm proper coverage due to the reflective metal layer underneath
Solution Approach 1:
The patent extracts or removes the organic layer material from the second metal layer region, creating a deliberate gap or non-covered area. This extraction creates a non-reflective inspection window through the slit structure, allowing optical measurement and confirmation of the organic layer's peripheral edge position and coverage quality without the interference of light reflection from the metal layer.
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 configuration allows for secure confirmation of the organic layer's position during manufacturing, reducing the number of defective panels and improving the inspection process by minimizing light reflection from the metal layers.
Implementation Method 1
the first metal layer and the second metal layer are each provided across the slit, and are in contact with each other inside the slit
Implementation Method 2
a metal material such as silver (Ag) having high reflectivity is suitably used for the metal layer. Thus, due to light reflected by the metal layer, it is difficult to confirm a coating position of the material forming the organic layer
Data Source
AI summary
A first metal layer provided on a resin substrate layer, a flattening film provided on the first metal layer, a second metal layer and a plurality of organic EL elements provided on the flattening film, and a sealing film covering the plurality of organic EL elements are provided. An organic layer provided in the sealing film includes a circumferential end edge positioned in a frame region. A slit overlapping the circumferential end edge of the organic layer is formed in an outer side of the flattening film. The first metal layer and the second metal layer are in contact with each other inside the slit. An opening is formed in a metal layer of the first metal layer and the second metal layer, the opening exposing an interlayer insulating film from the metal layer of the first metal layer and the second metal layer at a position at which the organic layer and the slit overlap each other.