Display Panel Contact Hole Formation via Dual-Layer Protection
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Solution Overview
Problem
In the production of organic electroluminescence (EL) display panels, the formation of contact holes exposes the first layer to gas or liquid chemicals, leading to degradation, especially when the first layer has low tolerance, and pin-holes in metal contacts can allow these chemicals to penetrate, causing further issues.
Innovation Solution
A method involving a base substrate with a first layer and a second layer, where the second layer's opening is smaller than the first layer's opening, covering the internal side surfaces of the first layer, thereby protecting it from subsequent process chemicals and preventing penetration through pin-holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If etching is performed on both the passivation film and planarizing film in a single process to form contact holes, then the manufacturing process is simplified and productivity is improved, but the first layer (passivation film) is exposed to gas or liquid chemicals causing degradation
Solution Approach 1:
The patent divides the contact hole formation process into two separate etching steps: first etching the planarizing film to form a recess, then etching the passivation film. This segmentation allows the passivation film to be protected during the first etching step, preventing chemical exposure and degradation while still achieving efficient contact hole formation through the sequential process
Solution Approach 2:
The patent performs preliminary action by forming a recess in the planarizing film before etching the passivation film. This preliminary recess formation creates a protective cavity that shields the passivation film from direct chemical exposure during subsequent etching operations, preventing degradation while maintaining process efficiency
2Adaptability or versatility
If the first layer is made of material with low tolerance against chemicals to achieve desired electrical properties, then device performance is improved, but the first layer degrades when exposed to process chemicals during contact hole formation
Solution Approach 1:
The patent applies preliminary anti-action by creating a protective recess structure in the planarizing film before the passivation film is exposed to chemicals. This preliminary structural preparation counteracts the harmful chemical exposure, allowing the use of chemically sensitive materials in the passivation film that provide desired electrical properties without suffering from degradation during processing
3Loss of substance
If metal contacts are formed with pin-holes to reduce material usage and cost, then manufacturing cost is reduced, but gas or liquid chemicals can penetrate through pin-holes to reach and degrade the first layer
Solution Approach 1:
The patent provides beforehand cushioning by forming a recess in the planarizing film that acts as a protective barrier before chemicals can reach the passivation film. This preliminary protective structure cushions against the harmful effect of chemical penetration through pin-holes in metal contacts, allowing the use of thinner or less dense metal contacts while still protecting the underlying layers
Data Source
AI summary
In a method for producing a display panel, a base substrate having an upper surface on which an electrode is located is prepared. A first layer having a first opening overlapping with the electrode in plan-view is formed on the base substrate. A second layer having a second opening overlapping with the first opening in plan-view is formed on the first layer. The second opening has a smaller area than the first opening in plan-view. A wiring layer is formed in the first opening and the second opening, in contact with the electrode. The second layer includes a portion located on an upper surface of the first layer and a portion located in the first opening. The portion of the second layer located in the first opening covers an internal side surface of the first layer located around the first opening.