Light-Emitting Element Contact Electrode Lift-Off Structure
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Solution Overview
Problem
Current display devices face challenges in efficiently forming contact electrodes for light emitting elements, particularly in ensuring reliable contact and preventing material disconnection during the fabrication process.
Innovation Solution
A method of fabricating display devices using a lift-off process to form contact electrodes in contact with insulating patterns, where the insulating patterns are designed to have specific surface configurations to enhance contact area and prevent material disconnection, including forming a metal layer on the electrodes and lift-off layer, and removing the lift-off layer to create contact electrodes in contact with the insulating patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If contact electrodes are formed using conventional fabrication methods, then the fabrication process is simple, but the contact area with light emitting elements is insufficient and material disconnection occurs
Solution Approach 1:
The patent introduces an insulating pattern as an intermediary structure between the contact electrode and the light emitting element. This insulating pattern includes a first surface that contacts the contact electrode and a second surface that contacts the light emitting element, creating a reliable contact interface while preventing material disconnection. The intermediary structure resolves the contradiction by providing both sufficient contact area and structural stability without requiring complex fabrication processes.
Solution Approach 2:
The insulating pattern is designed with a three-dimensional structure that extends vertically between the contact electrode and the light emitting element. This dimensional approach increases the contact area by utilizing the vertical space, allowing the insulating pattern to contact both the electrode and the light emitting element simultaneously. This resolves the contradiction by achieving reliable contact without complicating the fabrication process.
2Reliability
If the insulating pattern is designed with larger contact area, then the reliability of contact electrodes improves, but the amount of insulating material increases
Solution Approach 1:
The insulating pattern is designed with non-uniform cross-sectional areas along its height, creating local quality variations. The first cross-sectional area (at the contact electrode interface) and the second cross-sectional area (at the light emitting element interface) are optimized independently to provide sufficient contact area only where needed. This resolves the contradiction by maintaining high reliability at contact interfaces while minimizing the total insulating material quantity through tapered or stepped geometry.
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 method improves the reliability of contact electrodes, increases the contact area with light emitting elements, and reduces the risk of material disconnection, thereby enhancing the stability and efficiency of the display device fabrication process.
Implementation Method 1
A method of fabricating display devices using a lift-off process to form contact electrodes in contact with insulating patterns
Data Source
AI summary
A display device includes a substrate, a first electrode and a second electrode which are spaced apart from each other on the substrate, a first insulating pattern on the substrate to cover at least a portion of each of the first electrode and the second electrode, a light emitting element between the first electrode and the second electrode on the first insulating pattern, a first contact electrode in contact with the first electrode and one end portion of the light emitting element, a second contact electrode in contact with the second electrode and another end portion of the light emitting element, and a second insulating pattern on the light emitting element and of which at least a portion is in contact with each of the first contact electrode and the second contact electrode, wherein the second insulating pattern includes a first upper surface not in contact with the first contact electrode or the second contact electrode.