Undercut Compensating Member for LCD Substrate Contact Holes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing manufacturing processes for liquid crystal display (LCD) substrates often result in deteriorated contact characteristics due to undercuts formed during etching, leading to decreased yield and increased manufacturing costs, especially as integration increases.
Innovation Solution
Incorporating an undercut compensating member with a lower etching rate than the insulating layer, which is strategically positioned to prevent undercuts and improve electrical connections, allowing for the formation of contact holes using fewer masks and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used to form contact holes, then manufacturing process is simple, but undercut is formed in the insulating layer causing deteriorated contact characteristics
Solution Approach 1:
An undercut compensating member is formed on the insulating layer before the contact hole etching process. This member has a width greater than the contact hole opening, so during etching it prevents the formation of undercut in the insulating layer by providing mechanical support and guiding the etch front, thereby ensuring vertical sidewalls and improved contact characteristics.
Solution Approach 2:
The undercut compensating member acts as an intermediary element between the etching process and the insulating layer. It temporarily supports the insulating layer during etching to prevent undercut formation, and is subsequently removed after serving its protective function, leaving no residue that would affect contact characteristics.
2Manufacturing precision
If multiple masks are used to prevent undercut and improve contact characteristics, then contact characteristics are improved, but manufacturing cost increases
Solution Approach 1:
The undercut compensating member formation process is merged with the existing insulating layer formation process. Both the insulating layer and the compensating member are formed in the same deposition step, eliminating the need for separate masking and etching steps that would otherwise be required to create the compensating structure, thereby reducing manufacturing cost while improving contact characteristics.
Solution Approach 2:
The undercut compensating member serves multiple functions: it prevents undercut formation during contact hole etching, provides a template for contact hole alignment, and can be integrated with subsequent processing steps. This multi-functionality reduces the need for additional specialized structures and processes, lowering overall manufacturing cost.
3Manufacturing precision
If integration of array substrate is increased, then display quality is improved, but yield decreases due to deteriorated contact characteristics
Solution Approach 1:
The undercut compensating member is formed in advance before contact hole etching to prevent undercut formation. This preliminary protective structure ensures reliable contact characteristics even as device integration increases, maintaining yield by preventing contact failures that would otherwise occur in highly integrated displays.
Solution Approach 2:
The undercut compensating member provides a physical reference structure that guides the etching process, ensuring consistent contact hole dimensions and positions. This feedback mechanism maintains manufacturing precision and yield across batches, even as display integration and complexity increase.
Data Source
AI summary
A display substrate includes a substrate, a first insulating layer, an undercut compensating member, a first electrode, a second insulating layer and a first conductive pattern. The first insulating layer is formed on the substrate. The undercut compensating member is formed on the first insulating layer. The undercut compensating member has an etching rate smaller than that of the first insulating layer. The first electrode is formed on a portion of the undercut compensating member. The second insulating layer is formed on the first insulating layer. The second insulating layer has a contact hole through which a portion of the first electrode and a remaining portion of the undercut compensating member. The first conductive pattern electrically connected to the first electrode through the contact hole.