LCD Passivation Groove via Selective Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing process of liquid crystal display (LCD) devices is costly due to the complexity and number of processes involved, particularly in forming electric-field generating electrodes on a single thin film transistor display panel with multiple insulating layers.
Innovation Solution
The solution involves reducing the number of manufacturing processes by forming a display device with a first substrate that includes a gate line, data line, and passivation layers with specific contact holes, and a common electrode with a residual pattern, which allows for a groove between passivation layers, and a pixel electrode connected to a thin film transistor, using different deposition temperatures and pressures for thin film layers to achieve distinct etching rates and simplify the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple insulating layers are disposed between the thin film transistor and the electric-field generating electrode, then electrical insulation is improved, but the number of manufacturing processes increases
Solution Approach 1:
The patent merges the formation of contact holes through multiple insulating layers into a single etching process. By designing the insulating layers with different etching rates, the groove is formed by etching through the upper insulating layer to a predetermined depth without completely removing the lower insulating layer, thereby creating the necessary electrical connection structure in one step rather than requiring separate processes for each layer.
Solution Approach 2:
The patent utilizes parameter changes in the etching process by controlling the etching depth and selecting etching conditions that exploit the different etching rates of the first and second insulating layers. This allows selective removal of material to form the groove at the interface between layers, achieving the desired structure through parameter optimization rather than additional process steps.
2Reliability
If contact holes are formed in multiple insulating layers, then electrical connection is achieved, but manufacturing cost increases
Solution Approach 1:
The patent combines the formation of contact holes through multiple insulating layers into a single etching operation. The groove is formed by etching through the second insulating layer and partially into the first insulating layer, creating both the contact hole and the groove structure simultaneously, thereby reducing manufacturing cost by eliminating redundant process steps.
Solution Approach 2:
The patent performs preliminary action by forming the groove structure during the contact hole etching process itself. By planning the etching depth and conditions in advance to exploit different etching rates, the groove is created as a byproduct of the contact hole formation, avoiding the need for separate groove formation processes and reducing overall manufacturing cost.
3Manufacturing precision
If different insulating layers are etched at different rates, then selective groove formation is improved, but process control difficulty increases
Solution Approach 1:
The patent utilizes parameter changes by selecting etching conditions that maximize the difference in etching rates between the first and second insulating layers. By controlling parameters such as etching gas composition, power, and pressure, the process achieves selective etching where the second layer is removed much faster than the first, creating the groove with high precision through parameter optimization rather than complex process control.
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 manufacturing costs and prevents electrical defects by simplifying the process and ensuring proper electrical connections, while maintaining the functionality of the LCD device.
Implementation Method 1
The forming of the first passivation layer may include forming a plurality of thin film layers deposited under different temperature and pressure conditions
Data Source
AI summary
A display device includes a gate line and a data line on a first substrate. A first passivation layer disposed thereon has a first contact hole. A second passivation layer on the first passivation layer has a second contact hole. A common electrode is disposed on the second passivation layer and a residual pattern is disposed on a drain electrode. A third passivation layer, having a third contact hole, is disposed on the common electrode. A pixel electrode, connected to the drain electrode, is disposed on the third passivation layer. A groove is defined between the first and second passivation layers. The common electrode has a open circuit from the residual pattern thereof.