AH-IPS LCD Common Electrode Formation Reducing Mask Processes
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Solution Overview
Problem
Conventional AH-IPS type LCD manufacturing processes are inefficient, requiring multiple mask processes and increasing manufacturing costs.
Innovation Solution
The proposed solution involves a reduced number of mask processes by forming a common electrode with an under cut shape, allowing for efficient etching and planarization, and using a separate region for the third passivation layer to connect the pixel electrode to the drain electrode through a drain contact hole, thereby simplifying the manufacturing method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional AH-IPS type LCD manufacturing processes are used with multiple mask processes, then manufacturing precision is maintained, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the formation of the common electrode and pixel electrode into a single mask process. The conductive layer is patterned to form both electrodes simultaneously, eliminating the need for separate mask processes for each electrode, thus reducing the total number of mask processes from 6-7 to fewer steps while maintaining manufacturing precision
Solution Approach 2:
The conductive layer serves multiple functions: it forms both the common electrode and pixel electrode, and also provides electrical connection between them. This multi-functional design eliminates the need for separate structures and processes for each function, simplifying the overall manufacturing process
2Productivity
If the number of mask processes is reduced, then manufacturing efficiency improves, but manufacturing precision may deteriorate
Solution Approach 1:
The patent applies local quality by creating different electrode patterns from a single conductive layer. The common electrode and pixel electrode are formed with different geometries and positions within the same mask process, allowing each electrode to have its specific required precision while being manufactured in one step
Solution Approach 2:
The conductive layer acts as an intermediary that enables the formation of both electrodes with precise patterns. By using photolithography and etching processes on this single layer, the patent achieves accurate positioning and shaping of both electrodes simultaneously, maintaining manufacturing precision despite reduced process steps
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 reduces the number of manufacturing processes from 6 or 7 to 4, enhancing efficiency and lowering costs while maintaining the performance of the AH-IPS type LCD.
Implementation Method 1
a fringe field is produced between the common electrode 51 and the pixel electrode 52, thus arrangement of liquid crystal molecules is changed by the fringe field
Data Source
AI summary
A liquid crystal display device includes a gate electrode; a gate insulating layer on the gate electrode; an active layer on the gate insulating layer corresponding to the gate electrode; source and drain electrodes on the active layer; a first passivation layer on the source and drain electrodes; a common electrode on the first passivation layer; a second passivation layer on the common electrode, covering the common electrode, and having a separate region from the first passivation layer at a thickness of the common electrode; a pixel electrode on the second passivation layer and connected to the drain electrode through a drain contact hole; and a common line at a same layer as the pixel electrode and connected to the common electrode.