Display Panel Drain Electrode Material Differentiation
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Solution Overview
Problem
In existing display panels, conductive structures in lower layers are often overetched during the formation of vias, leading to poor electrical connections between conductive layers, which affects the reliability of the display panel.
Innovation Solution
The use of a display panel design where the material of the first drain electrode is different from the material of the first source electrode, with a metal layer provided between the electrodes to prevent overetching during the etching process, ensuring a reliable electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a via is formed in the insulation layer to electrically connect conductive structures in different layers, then electrical connection between layers is achieved, but the conductive structure in the lower layer may be overetched, resulting in poor electrical connection
Solution Approach 1:
The patent applies local quality by using different materials for the first source electrode and first drain electrode. The first source electrode uses a material (e.g., aluminum alloy) that is resistant to overetching, while the first drain electrode uses a different material that can be precisely etched. This localized material differentiation allows the etching process to selectively remove the drain electrode material without damaging the source electrode, thereby preventing overetching while maintaining good electrical connection.
Solution Approach 2:
The patent changes the material parameter of the electrodes to resolve the etching contradiction. By selecting materials with different etching characteristics (e.g., different etching speeds, etching selectivity), the patent enables precise control over the etching process. The first drain electrode material is chosen to be more easily etched than the first source electrode material, allowing the via etching to stop at the desired depth without penetrating into or damaging the source electrode, thus preventing overetching while ensuring reliable electrical connection.
2Ease of manufacture
If the same material is used for both source electrode and drain electrode, then manufacturing process is simplified, but overetching of the drain electrode occurs during via formation
Solution Approach 1:
The patent implements local quality by differentiating the material composition at different locations within the electrode structure. The first source electrode and first drain electrode use different materials tailored to their specific functional requirements. The drain electrode material is selected for ease of etching, while the source electrode material is selected for resistance to overetching. This localized material optimization maintains manufacturing feasibility while preventing overetching issues that would compromise electrical connection reliability.
Solution Approach 2:
The patent employs composite materials strategy by using different material compositions for the source and drain electrodes. This may involve using aluminum alloy for one electrode and a different metal or alloy for the other, or using multi-layer composite structures with different materials. These composite material choices enable differential etching behavior, allowing the via formation process to precisely define the drain electrode connection without penetrating into or damaging the source electrode, thereby ensuring reliable electrical connection while maintaining manufacturing practicality.
Data Source
AI summary
A display panel and a display device are provided. The display panel includes a substrate, a driving unit including a first transistor, and at least one light-emitting element. The first transistor includes a first source electrode and a first drain electrode that are located at a side of the at least one light-emitting element close to the substrate. Each of the at least one light-emitting element includes a first electrode, a light-emitting layer, and a second electrode that are sequentially stacked. The first electrode is connected to the first drain electrode through a first via, and the first drain electrode is located at a side of the first source electrode close to the substrate. A material of the first drain electrode is different from a material of the first source electrode.