OLED Display Frame Line Insulation for Short-Circuit Prevention
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Solution Overview
Problem
In OLED display devices, the formation of organic sealing films using inkjet technology can lead to short-circuiting between frame lines due to residual metal films, which are unavoidable when patterning metal films for electrodes and damming walls made of the same material.
Innovation Solution
A display device structure featuring a sequential stack of thin film transistor layers, light-emitting elements, and sealing films, with a specific arrangement of damming walls and interlayer insulation films to prevent short-circuiting between frame lines by covering edges of frame lines with an interlayer insulation film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the damming wall is made of the same material and in the same layer as the planarization film, then the manufacturing process is simplified, but residual metal film remains between frame lines causing short-circuiting
Solution Approach 1:
An insulating film is introduced as an intermediary layer between the conductive frame lines to prevent electrical short-circuiting. This mediator layer is formed on the planarization film in regions where frame lines are adjacent, providing electrical isolation without requiring changes to the frame line structure itself.
Solution Approach 2:
The planarization film region is segmented into different functional zones: regions with the insulating film for electrical isolation and regions without the insulating film for maintaining design flexibility. This segmentation allows simultaneous achievement of electrical isolation and manufacturing simplicity in different areas.
2Manufacturing precision
If a thick resist pattern is formed for patterning metal film, then the metal film can be properly patterned, but residual metal film remains on the bottom portion of the sidewall of the damming wall
Solution Approach 1:
The residual metal film that would normally cause harmful short-circuiting is converted into a beneficial structure by forming the insulating film over it. The previously harmful residual metal is now encapsulated and electrically isolated, transforming the manufacturing challenge into an acceptable feature.
Solution Approach 2:
The insulating film serves as a mediator that eliminates the harmful effect of residual metal film. By placing this insulating layer between adjacent frame lines, the residual metal that cannot be completely removed during patterning is electrically isolated, preventing short-circuiting.
3Productivity
If the first frame line and second frame line run next to each other through the damming wall, then power supply lines can reach terminal portions efficiently, but short-circuiting between frame lines occurs due to residual metal film
Solution Approach 1:
The region between adjacent frame lines is segmented into an insulated region (with insulating film) and non-insulated regions. This segmentation allows frame lines to run closely together for efficient electrical connection while maintaining electrical isolation in critical areas where short-circuiting could occur.
Solution Approach 2:
The insulating film acts as an intermediary barrier between the first and second frame lines that run adjacent to each other. This mediator enables the frame lines to be positioned close together for efficient power distribution while preventing electrical short-circuiting through the residual metal film.
Data Source
AI summary
A display device includes a thin film transistor layer including a first interlayer insulation film, a first wiring layer, a second interlayer insulation film, a second wiring layer, a third interlayer insulation film, a third wiring layer, a first planarization film, a fourth wiring layer, and a second planarization film; and a first damming wall in a frame area separated from the first and second planarization film in a display area by a first slit. There is provided a fourth interlayer insulation film between the third and fourth wiring layer. The fourth interlayer insulation film covers an edge of either one or both of a first frame line and a second frame line as the third wiring layer in a region where the first frame line is located opposite the second frame line in a plan view, the edge facing the display area and being exposed in the first slit.