Terminal Wiring Protection in Display Devices
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Solution Overview
Problem
In organic EL display devices, the removal of sealing films to expose terminal wiring can lead to connection failures due to physical flaws and over-etching, increasing manufacturing complexity and risk of film removal.
Innovation Solution
A display device design featuring a terminal region with a high etching selectivity insulating film and a preventing film, where the insulating film is formed of silicon nitride and the preventing film is formed of silicon oxide or aluminum oxide, generating electrostatic capacitance and protecting the terminal wiring, and a method involving etching the sealing film to expose the terminal wiring while preventing the insulating film from being removed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing film is formed to cover the entire array substrate including terminal wiring, then the organic EL elements are protected from water molecules, but the terminal wiring cannot be accessed for connection and requires additional etching steps
Solution Approach 1:
The sealing film is segmented into two regions: a first sealing film covering the display region and pixel wiring, and a second sealing film covering the terminal region and terminal wiring. This segmentation allows the terminal wiring to be accessible for connection while maintaining protection in the display region, eliminating the need to remove the entire sealing film.
Solution Approach 2:
Different sealing film configurations are applied to different regions of the substrate. The display region receives a complete sealing film for protection, while the terminal region has a different sealing arrangement that allows electrical connection. This local differentiation resolves the contradiction between protection and accessibility.
2Reliability
If a protective film is formed over the terminal wiring to prevent physical flaws, then connection reliability improves, but the film may be removed during etching of the sealing film
Solution Approach 1:
The sealing film structure uses composite materials with different etching characteristics. The first sealing film (silicon nitride) and second sealing film (organic resin) have different etching selectivity ratios, allowing selective removal or protection during manufacturing processes. This composite structure enables the protective function while maintaining precision in film removal control.
Solution Approach 2:
The second sealing film acts as an intermediary protective layer over the terminal wiring. It provides physical protection during manufacturing while being removable or selectively processed due to its different material properties compared to the first sealing film, thus protecting the terminal wiring without preventing necessary etching operations.
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 enhances yield by preventing flaws and reducing manufacturing steps, ensuring reliable electrical connections and minimizing the risk of film removal during the terminal exposing process.
Implementation Method 1
the insulating film generating an electrostatic capacitance between the anode electrode and the pixel wiring
Implementation Method 2
the sealing film on a terminal wiring is removed through etching
Data Source
AI summary
A display device, including a display region formed of a plurality of pixels, and a terminal region formed on an outer side of the display region, includes a terminal wiring formed in the terminal region, a pixel wiring formed in each of the plurality of pixels, an insulating film, which is formed in the terminal region on an upper layer of the terminal wiring, and is formed in the display region on an upper layer of the pixel wiring, and a preventing film formed in the terminal region on an upper layer of the insulating film. The terminal wiring is exposed in an electrical connection region of the terminal region.