Display Substrate Etching Stopper Design
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Solution Overview
Problem
The production cost of touchscreen panel integrated display devices is increased due to the requirement of a dedicated photomask for patterning insulating films during the dry etching process, which is necessary to prevent damage to signal lines and electrodes.
Innovation Solution
A display substrate configuration where the second insulating film acts as an etching stopper, allowing the use of a shared photomask for forming contact holes, eliminating the need for a dedicated photomask for the second insulating film and reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an insulating film is interposed as an etching stopper between the first protective layer and the metal film, then the first protective layer is protected from etching damage, but a dedicated photomask is required to pattern the insulating film, increasing production cost
Solution Approach 1:
The patent removes the dedicated etching stopper insulating film from the structure. Instead of adding a separate insulating film layer, the design relies on the existing first protective layer to serve as the etching stopper, thereby eliminating the need for a dedicated photomask and reducing production costs while maintaining etching precision
Solution Approach 2:
The first protective layer is given dual functionality: it serves both as a protective layer for the data line and as an etching stopper during dry etching of the signal line. This multi-functionality eliminates the need for a separate etching stopper layer and its associated photomask, resolving the contradiction between manufacturing precision and production cost
2Reliability
If a dedicated photomask is used to pattern the insulating film, then the signal line connection is ensured, but the production cost increases
Solution Approach 1:
The first protective layer serves multiple functions including signal line protection and etching stopper, allowing existing photomasks to be reused without requiring dedicated photomasks for etching stopper patterning, thus maintaining reliability while reducing production cost
Solution Approach 2:
The patent merges the protective function and etching stopper function into a single layer (the first protective layer), eliminating the need for separate patterning steps and dedicated photomasks, thereby ensuring signal line connection reliability while reducing manufacturing costs
Data Source
AI summary
A display substrate includes: a switching element including a pixel connection electrode composed of a first conductive film; a pixel electrode composed of a third conductive film and including a portion overlapping the pixel connection electrode; a pixel contact hole drilled through first, second, and third insulating films at a position overlapping the pixel connection electrode and the pixel electrode; a wiring composed of a second conductive film; a wiring connection portion including a portion overlapping the wiring; a first wiring contact hole drilled through the third insulating film at a position overlapping the wiring and the wiring connection portion; a touch lead-out wiring including a portion overlapping a section of the wiring connection portion not overlapping the wiring; and a second wiring contact hole drilled through the first to the third insulating films at a position overlapping the wiring connection portion and the lead-out wiring.