Display Substrate Masking Process Prevents Waterfall Defects
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Solution Overview
Problem
The existing manufacturing processes for display substrates, particularly in LCD devices, face challenges in reducing the number of masks used while maintaining element characteristics and driving reliability, often resulting in display defects like 'waterfall' when attempting to simplify the masking process.
Innovation Solution
A display substrate is manufactured using a simplified process with a gate line, gate insulation layer, data line, switching element, protection insulation layer, gate pad portion, and data pad portion, where the semiconductor pattern is not formed below the data line, thereby preventing display defects. This is achieved through a method involving multiple masking steps to form specific patterns and connections without the semiconductor pattern being between the data line and the gate insulation layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a four-masking process is used to reduce manufacturing complexity, then the number of masks is reduced, but the semiconductor pattern is formed below the data line causing display defects like waterfall
Solution Approach 1:
The patent segments the data line formation into two separate masking steps: first forming the data line pattern without semiconductor, then forming contact holes through the data line to reach the semiconductor pattern below. This segmentation prevents the semiconductor from being improperly positioned below the data line while still achieving manufacturing simplification.
Solution Approach 2:
The patent performs preliminary action by forming the data line pattern in an earlier masking step before forming the contact holes. This preliminary formation of the data line structure prevents subsequent display defects while maintaining the simplified four-masking process.
2Reliability
If more masks are used to prevent display defects, then display quality is maintained, but manufacturing time and costs increase
Solution Approach 1:
The patent merges the formation of data lines and contact holes into a coordinated four-masking process, where the fourth mask simultaneously defines both the data line pattern and the contact hole positions. This merging achieves the same quality assurance as separate masking steps while reducing total manufacturing time and cost.
3Ease of manufacture
If the semiconductor pattern is formed below the data line to simplify masking, then manufacturing is simplified, but display defects like waterfall occur
Solution Approach 1:
The patent introduces contact holes as an intermediary structure that connects the data line formed in the fourth mask to the semiconductor pattern formed earlier. This intermediary allows the semiconductor to be positioned below the data line for manufacturing simplicity while preventing direct harmful contact that causes waterfall defects.
Data Source
AI summary
A display substrate includes a gate line, a gate insulation layer, a data line, a switching element, a protection insulation layer, a gate pad portion and a data pad portion. The gate insulation layer is disposed on the gate line. The switching element is connected to the gate line and the data line. The protection insulation layer is disposed on the switching element. The gate pad portion includes a first gate pad electrode which makes contact with an end portion of the gate line through a first hole formed through the gate insulation layer, and a second gate pad electrode which makes contact with the first gate pad electrode through a second hole formed through the protection insulation layer. The data pad portion includes a data pad electrode which makes contact with an end portion of the data line through a third hole formed through the protection insulation layer.