Through Hole Insulation Film Structure for Display Device Yield
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Solution Overview
Problem
The existing multi-layered insulation film structure in display devices through holes often results in increased connection resistance and yield rate issues due to surface roughness and disconnection defects, whether the upper-layer insulation film opening is larger or smaller than the lower-layer opening.
Innovation Solution
A display device design where the side surface of the opening in the first insulation film is partially covered by the second insulation film, with the outer circumference of the bottom surfaces of both openings intersecting, and the first insulation film is formed using dry etching while the second is formed by coating or printing, reducing surface roughness and disconnection risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the opening formed in the upper-layer insulation film is larger than the opening formed in the lower-layer insulation film, then the stepped portion or edge is formed on the side surface of the through hole, but the pixel electrode is liable to be easily disconnected by the stepped portion or the edge, bringing about the lowering of the yield rate
Solution Approach 1:
The patent applies local quality by creating different opening sizes at different locations (upper-layer vs lower-layer insulation films) to achieve both electrical connection and mechanical stability. The upper-layer opening is made larger to ensure electrical contact, while the lower-layer opening is made smaller to provide structural support and prevent disconnection, thus resolving the contradiction between connection quality and yield rate.
2Reliability
If the opening formed in the upper-layer insulation film is smaller than the opening formed in the lower-layer insulation film, then only the upper-layer insulation film is exposed on the side surface of the through hole and the stepped portion or the edge is reduced, but the electrical connection becomes insufficient and point defects frequently occur
Solution Approach 1:
The patent applies local quality by creating different opening sizes at different locations (upper-layer vs lower-layer insulation films) to achieve both electrical connection and mechanical stability. The upper-layer opening is made larger to ensure electrical contact, while the lower-layer opening is made smaller to provide structural support and prevent disconnection, thus resolving the contradiction between connection quality and yield rate.
3Reliability
If the multi-layered insulation film structure is used in the through hole portion, then the insulation properties are enhanced, but the connection resistance increases and yield rate decreases due to surface roughness and disconnection defects
Solution Approach 1:
The patent applies local quality by creating different opening sizes at different locations (upper-layer vs lower-layer insulation films) to achieve both electrical connection and mechanical stability. The upper-layer opening is made larger to ensure electrical contact, while the lower-layer opening is made smaller to provide structural support and prevent disconnection, thus resolving the contradiction between connection quality and yield rate.
Solution Approach 2:
The patent applies dimensionality change by considering the vertical dimension (different layers) separately from the horizontal dimension (opening size). By varying the opening size in the vertical direction across different insulation layers, the patent achieves both good electrical connection (through larger upper opening) and structural integrity (through smaller lower opening), resolving the contradiction between insulation performance and connection quality.
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 effectively reduces connection defects and contact resistance, enhancing the yield rate by ensuring stable electrical connections between conductive layers through the through hole.
Implementation Method 1
the first insulation film is formed using dry etching
Data Source
AI summary
The present invention enhances a manufacturing yield rate relating to through holes. In a display device which includes a first conductive layer formed on a substrate and a second conductive layer which is formed on the first conductive layer by way of insulation films of two or more layers and connects the first conductive layer and the second conductive layer via a through hole, in the through hole portion, a side surface of an opening formed in the insulation film arranged on the first conductive layer side out of the insulation films of two or more layers includes a portion thereof which is covered with the insulation film arranged on the second conductive layer side out of the insulation films of two or more layers and an exposed portion.