OLED Display Insulating Layer Contact Hole Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In organic light emitting diode (OLED) displays, variations in the widths of active layers of thin film transistors across a substrate can lead to differences in current values supplied to OLEDs, affecting display quality and luminance.
Innovation Solution
The OLED display incorporates a first insulating layer with a greater number of contact holes in the outer region than in the central area, including dummy contact holes that do not overlap the active layers, to minimize differences in transistor characteristics and current values across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a photolithography process is used to manufacture thin film transistors, then manufacturing precision is improved, but variations in active layer widths still occur across the substrate leading to current value differences
Solution Approach 1:
The patent applies local quality by configuring different numbers of contact holes in different regions of the substrate. Specifically, the outer region of the substrate is provided with a greater number of contact holes compared to the central area. This regional differentiation compensates for the width variations of active layers that occur across the substrate during photolithography, thereby equalizing current values and improving reliability without sacrificing manufacturing precision.
2Reliability
If the number of contact holes is increased in the outer region, then current value uniformity is improved, but device complexity increases
Solution Approach 1:
The patent implements local quality by strategically placing contact holes only where needed - specifically, the outer region of the substrate receives additional contact holes compared to the central area. This targeted approach improves current value uniformity while minimizing the overall increase in device complexity, as the contact hole distribution is optimized locally rather than uniformly across the entire substrate.
Data Source
AI summary
An organic light emitting diode display includes a substrate including a display area and a non-display area adjacent the display area, a plurality of organic light emitting diodes at the display area of the substrate, a plurality of thin film transistors at the display area of the substrate, each of the plurality of thin film transistors being connected to a corresponding one of the plurality of organic light emitting diodes, and a first insulating layer covering an active layer of the plurality of thin film transistors, the first insulating layer having a greater number of contact holes at an outer region of the display area than at a central area of the display area.