Display Device Pad Wiring Etching-Stop Layer
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Solution Overview
Problem
Manufacturing errors in the formation of contact holes and hole filling portions in display devices, such as organic electroluminescence display devices, often lead to poor electrical connections between wiring layers, resulting in inefficient pixel circuit performance.
Innovation Solution
Incorporating an etching-stop layer that overlaps with the boundary between the pad and line portions of the wiring layers, ensuring that the pad and line portions remain integrated and connected, even with manufacturing errors, by preventing separation during the formation of contact holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact holes and hole filling portions are formed to connect wiring layers, then electrical connection between layers is established, but manufacturing errors cause poor connection and separation between pad portions and line portions
Solution Approach 1:
The patent applies preliminary action by forming the hole filling portion to extend beyond the contact hole boundaries before final processing. This over-extension ensures that even if manufacturing errors occur during contact hole formation, the hole filling portion maintains continuous electrical connection between the pad portion and line portion, preventing separation and ensuring reliable electrical connection despite positioning inaccuracies
Solution Approach 2:
The patent changes the geometric parameters of the hole filling portion, specifically extending its width and length beyond the contact hole dimensions. By making the hole filling portion larger than the contact hole that contains it, the design compensates for manufacturing tolerances and ensures that the electrical connection path remains intact even when contact hole positioning deviates from specifications
2Device complexity
If the hole filling portion is formed entirely inside the contact hole, then the structure is compact, but manufacturing errors lead to separation of pad portion and line portion
Solution Approach 1:
The patent applies preliminary action by forming the hole filling portion to extend beyond the contact hole boundaries before final processing. This over-extension ensures that even if manufacturing errors occur during contact hole formation, the hole filling portion maintains continuous electrical connection between the pad portion and line portion, preventing separation and ensuring reliable electrical connection despite positioning inaccuracies
Solution Approach 2:
The patent changes the geometric parameters of the hole filling portion, specifically extending its width and length beyond the contact hole dimensions. By making the hole filling portion larger than the contact hole that contains it, the design compensates for manufacturing tolerances and ensures that the electrical connection path remains intact even when contact hole positioning deviates from specifications
Data Source
AI summary
A display device includes: a second wiring layer on the first insulating film, the second wiring layer overlapping with a part of the first pad portion, the second wiring layer including a second pad portion not overlapping with the first line portion; an etching-stop layer overlapping with at least a boundary between the first pad portion and the first line portion; a second insulating film covering the second wiring layer, the second insulating film having a contact hole, the contact hole including a first area where the second insulating film, the first insulating film, and the first pad portion are penetrated, the contact hole including a second area where the second insulating film is penetrated and the second pad portion is a bottom; and a third wiring layer inside the contact hole, the third wiring layer connected to the first pad portion and the second pad portion.