TFT Array Substrate Reflecting Layer Mask Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The traditional manufacturing process of TFT array substrates for transflective LCDs is complicated and costly due to the need for additional masks to form a reflecting layer, increasing production difficulty and costs.
Innovation Solution
A method using a first multi-tone mask (MTM) to pattern a transparent conductive layer and a first metal layer to form a gate, common electrode, and reflecting layer, followed by a second MTM to pattern a gate insulation and semiconductor layer, and a third MTM to form sources and drains, reducing the number of masks required and simplifying the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional mask is used to form the reflecting layer in the traditional manufacturing process, then the reflecting layer can be formed, but the manufacturing process becomes more complicated and costly
Solution Approach 1:
The patent combines the formation of the gate electrode and reflecting layer into a single patterning step using one mask. The transparent conductive layer and first metal layer are patterned simultaneously to form both the gate electrode (where they overlap with the common electrode) and the reflecting layer (where the first metal layer remains on the common electrode), eliminating the need for a separate mask step that was traditionally required.
Solution Approach 2:
The first mask serves multiple functions: it patterns both the gate electrode and reflecting layer, and it defines the regions where the transparent conductive layer and first metal layer should be present. This multi-functional mask replaces what would traditionally require at least two separate masks, simplifying the manufacturing process while maintaining the required structural formations.
2Reliability
If an additional mask is used to form the reflecting layer, then the reflecting layer can be formed, but the manufacturing time increases
Solution Approach 1:
The patent merges the patterning operations for the gate electrode and reflecting layer into a single photolithography step. By using one mask to define both structures simultaneously, the manufacturing time is reduced as compared to the traditional approach that requires sequential patterning steps with separate masks.
Solution Approach 2:
The transparent conductive layer and first metal layer are deposited in advance across the entire substrate before patterning. This preliminary deposition allows the subsequent single mask step to simultaneously create both the gate electrode and reflecting layer, eliminating the need for time-consuming sequential deposition and patterning operations that would be required if the reflecting layer were formed in a later separate step.
3Reliability
If an additional mask is used to form the reflecting layer, then the reflecting layer can be formed, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple manufacturing operations into a single step using one mask for patterning both the gate electrode and reflecting layer. This reduces the total number of masks required, thereby lowering material costs and reducing the complexity of mask management, alignment, and registration that increases manufacturing costs in traditional multi-mask processes.
Solution Approach 2:
The first mask is designed to serve multiple purposes: patterning the gate electrode, defining the reflecting layer region, and controlling the deposition areas of both transparent conductive and metal layers. This multi-functional approach eliminates the need for additional specialized masks, reducing overall manufacturing costs while maintaining the required structural precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the manufacturing process, reduces costs, and increases yield by eliminating the need for a specific additional mask to form the reflecting layer, thereby decreasing production complexity and time.
Implementation Method 1
the transparent conductive layer and the first metal layer are formed in turn by sputter deposition
Data Source
AI summary
The present invention discloses a thin-film transistor (TFT) array substrate and a manufacturing method thereof. Depositing a transparent conductive layer and a first metal layer in turn on a substrate patterned by a first multi-tone mask (MTM) to form a gate, a common electrode and a reflecting layer; depositing a gate insulation layer and a semiconductor layer patterned by a second MTM to remain the semiconductor layer on the gate; and depositing a second metal layer patterned by a third MTM to form a source and a drain.