OLED Fabrication Mask Reduction via Simultaneous Electrode Formation
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Solution Overview
Problem
The conventional OLED fabrication process is lengthy and costly due to the high number of masks required, particularly when forming PMOS and NMOS transistors and via holes, which complicates the process, decreases yield, and increases production costs.
Innovation Solution
The OLED fabrication process is streamlined by forming metal interconnections and gate electrodes simultaneously with the first electrode, reducing the number of masks needed and simplifying the process, allowing for direct electrical connections between elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If metal interconnections and gate electrodes are formed separately using multiple masks, then electrical connections are established, but the fabrication process becomes lengthy and production costs increase
Solution Approach 1:
The patent merges the formation of metal interconnections and gate electrodes into a single simultaneous deposition step using one mask pattern, rather than forming them separately with multiple masks. This combining of operations reduces the total number of masks from 11-12 to 7-8 and shortens the fabrication process while maintaining proper electrical connections between pixels and driving circuits
Solution Approach 2:
The single mask pattern serves multiple functions by simultaneously defining both the metal interconnection regions and the gate electrode regions. This multi-functional mask approach eliminates the need for separate masks for each component, streamlining the fabrication process and reducing complexity
2Manufacturing precision
If multiple masks are used to form PMOS and NMOS transistors and via holes, then precise transistor structures are achieved, but yield decreases and production costs increase
Solution Approach 1:
The patent combines the formation of multiple transistor components and interconnections into simultaneous deposition steps, reducing the number of sequential mask operations from 11-12 to 7-8. This reduction in process steps minimizes cumulative alignment errors and processing variations, thereby improving yield while maintaining manufacturing precision
3Reliability
If conventional multi-mask process is used, then complete electrical connections are formed, but overall fabrication time increases
Solution Approach 1:
The patent merges multiple deposition operations into simultaneous processes where metal interconnections and gate electrodes are formed in the same step. This eliminates sequential waiting time between operations while ensuring complete electrical connections through carefully designed single-mask patterns that define all necessary conductive regions
Solution Approach 2:
The single mask pattern is designed in advance to simultaneously define all metal interconnection and gate electrode regions before deposition begins. This preliminary planning allows multiple components to be formed correctly in one operation, eliminating the need for subsequent corrective steps and reducing total fabrication time
Data Source
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AI summary
Provided are an organic light emitting display device (OLED) and a method of fabricating the same. When a metal interconnection (220) and a gate electrode (210,215) are formed at the same time or when a first electrode (290) is formed, interconnections for electrically connecting elements are formed. Thus, the number of used masks can be reduced, so that the overall fabrication process can be shortened and the production cost can be reduced.