Display Substrate Organic Layer Etching for Pixel Electrode Connectivity
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Solution Overview
Problem
In display devices, the use of an organic layer to reduce parasitic capacitance between the pixel electrode and the gate or data lines leads to disconnection of the pixel electrode, increased processing time, surface roughness, and reduced yield due to ashing processes, affecting the reliability and performance of the display apparatus.
Innovation Solution
A display substrate design that includes a base substrate with a switching element, a protecting layer, an organic layer exposing the drain electrode, a common electrode, and a pixel electrode connected through specific through holes, along with a method of manufacturing that involves partial exposure and controlled etching to minimize damage to the data metal pattern, using a molybdenum material for the drain electrode and transparent electrode layers to prevent surface damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an ashing process is performed to remove the under-cut, then the under-cut is eliminated, but the processing time increases and the organic layer surface becomes rough
Solution Approach 1:
The patent extracts or eliminates the need for the ashing process by designing the organic layer formation process to inherently prevent under-cut formation. Instead of adding a post-processing step to remove under-cuts, the methodology directly forms the organic layer with controlled thickness distribution that prevents under-cut creation in the first instance, thereby removing the harmful ashing step entirely.
Solution Approach 2:
The patent skips the ashing process step entirely by using a modified organic layer formation methodology that directly produces the desired result without requiring subsequent correction. The organic layer is formed with precise thickness control during the deposition process itself, allowing the process to rush through to completion without the time-consuming ashing intermediate step.
2Ease of manufacture
If the organic layer is patterned to form a contact hole, then the contact hole is formed, but the pixel electrode may be disconnected due to the under-cut
Solution Approach 1:
The patent applies preliminary action by pre-structuring the organic layer with controlled thickness distribution before contact hole formation. The organic layer is formed with a first region of predetermined thickness over the gate line and a second region of predetermined thickness over the data line, which prevents under-cut formation during subsequent patterning operations, thereby ensuring pixel electrode connectivity is maintained while still enabling contact hole formation.
Data Source
AI summary
A method of manufacturing a display substrate includes forming a gate insulation layer on the base substrate on which a gate metal pattern, forming a data metal pattern on the gate insulation layer, sequentially forming a insulation layer and an organic layer on the base substrate on which the data metal pattern is formed, partially exposing the organic layer, developing the organic layer to partially remove the organic layer on the data metal pattern and to expose at least a portion of the protecting layer on the gate metal pattern, forming a common electrode on the organic layer, forming a pixel electrode on the on the organic layer, and forming an insulation layer between the pixel electrode and the common electrode. An etching degree of a data metal may be controlled by controlling a thickness of a remained organic layer to reduce a damage of the data metal.