Array Substrate Passivation Segmentation for OLED Manufacturing
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Solution Overview
Problem
The manufacturing of organic electroluminescent display devices with polycrystalline silicon thin film transistors requires multiple mask processes, leading to high costs and reduced productivity, and existing attempts to simplify this process by skipping passivation layers can result in disconnection between signal lines or connection patterns.
Innovation Solution
An array substrate with a passivation layer of organic insulating material that covers auxiliary lines in the power source area, reducing the number of mask processes from 10 to 7 or 8 by forming a groove in the passivation layer to improve adhesion and prevent disconnection, while maintaining the integrity of the thin film transistor structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of mask processes is reduced from 10 to 7 or 8 by skipping passivation layers, then manufacturing time and costs are reduced, but disconnection between signal lines or connection patterns occurs
Solution Approach 1:
The passivation layer is segmented into a first passivation layer and a second passivation layer. The first passivation layer is formed to cover the thin film transistor, and the second passivation layer is formed subsequently to cover the first passivation layer and define connection holes. This segmentation allows the manufacturing process to be simplified while maintaining connection integrity, as each layer serves a specific protective and structural function.
Solution Approach 2:
The first passivation layer is formed in advance before the second passivation layer. This preliminary action provides a base protective layer that prevents disconnection during subsequent processing steps, while the second passivation layer is then formed to complete the protection and define the final connection structure.
2Ease of manufacture
If the number of mask processes is reduced from 10 to 7 or 8, then manufacturing costs are reduced, but adhesion properties of seal pattern deteriorate
Solution Approach 1:
The passivation structure is divided into two layers, where the first passivation layer provides adhesion enhancement for the seal pattern, and the second passivation layer provides protective coverage. This segmentation allows the adhesion function to be preserved while reducing the overall number of mask processes from 10 to 7 or 8.
Solution Approach 2:
The first passivation layer is specifically designed to enhance adhesion properties in regions where the seal pattern will be formed, while the second passivation layer provides general protection. This local quality differentiation ensures that adhesion requirements are met without requiring additional mask processes elsewhere in the structure.
3Productivity
If all passivation layers are skipped to reduce mask processes, then productivity increases, but disconnection between signal lines occurs
Solution Approach 1:
Instead of forming a single thick passivation layer or skipping passivation entirely, the structure is segmented into two thinner passivation layers. This segmentation maintains signal line continuity by providing distributed protection, while the reduced total number of mask processes (7 or 8 instead of 10) improves manufacturing efficiency.
Data Source
AI summary
An array substrate for an organic electroluminescent display device includes a substrate including a display area and a non-display area; a gate line and a data line; a thin film transistor including a semiconductor layer of polycrystalline silicon, a gate insulating layer, a gate electrode, an inter insulating layer, a source electrode, and a drain electrode; auxiliary lines formed of a same material and on a same layer as the data line; a passivation layer of organic insulating material and including a drain contact hole exposing the drain electrode, and an auxiliary line contact hole exposing one of the auxiliary lines; and a first electrode and a line connection pattern on the passivation layer, wherein the first electrode contacts the drain electrode and the line connection pattern contacts the one of the first auxiliary pattern.