Auxiliary Wiring Concave Structure for OLED Voltage Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The contact resistance between auxiliary wiring and the common electrode in organic electroluminescence display panels increases due to the formation of other layers, leading to insufficient reduction in voltage drop towards the center of the panel, especially when functional layers or protection layers are formed over the auxiliary wiring.
Innovation Solution
The inter-layer insulation film includes paired concave and non-concave portions, with the auxiliary wiring placed on these features, increasing the surface area of electric contact between the common electrode and the auxiliary wiring, thereby reducing contact resistance and voltage drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If auxiliary wiring is provided to reduce voltage drop toward the centre of the panel, then the combined resistance of the common electrode and auxiliary wiring is decreased, but contact resistance increases when functional layers or protection layers are formed over the auxiliary wiring
Solution Approach 1:
The invention transitions from a planar contact interface to a three-dimensional contact structure by forming concave portions in the inter-layer insulation film and corresponding convex portions on the auxiliary wiring. This dimensional change increases the contact surface area between the common electrode and auxiliary wiring, thereby reducing contact resistance even when functional layers are present.
Solution Approach 2:
The invention applies local structural modification by forming concave portions only in specific areas of the inter-layer insulation film where the auxiliary wiring is located. This localized approach increases contact area precisely where needed without affecting other regions of the panel structure.
2Illumination intensity
If transparent conductor such as ITO is used for common electrode to ensure optical transmissivity, then the common electrode is optically transmissive, but resistance is high causing great drops in voltage toward the centre of the panel
Solution Approach 1:
The invention uses a composite structure combining transparent conductor (ITO) with auxiliary wiring made of metal materials. This composite approach maintains optical transmissivity through the transparent conductor while the metal auxiliary wiring provides low resistance pathways to reduce voltage drops.
Solution Approach 2:
The auxiliary wiring acts as an intermediary element between the power supply and the common electrode. It provides an additional low-resistance electrical pathway that mediates the voltage distribution across the panel, reducing voltage drops without compromising optical transmissivity.
3Reliability
If metal material such as silver is used for common electrode to reduce resistance, then resistance is low, but sheet resistance increases due to thinning making the common electrode prone to great drops in voltage
Solution Approach 1:
The invention segments the electrical pathway by introducing auxiliary wiring that extends from the periphery to the center of the panel. This segmentation creates multiple parallel conduction paths, reducing the effective resistance and voltage drops across the common electrode.
Solution Approach 2:
The auxiliary wiring adds a dimensional aspect to the electrical conduction by creating a three-dimensional network of conductive paths. This additional dimension provides multiple routes for current flow, reducing resistance and voltage drops.
Data Source
AI summary
A organic EL display panel includes an inter-layer insulation film, a pixel electrode, auxiliary wiring, a partition layer, an organic light-emitting layer, and a common electrode. The inter-layer insulation film has at least one paired concave portion and non-concave portion disposed in a region over the auxiliary wiring, a top face of the concave portion being concave with respect to a top face of the non-concave portion, and the auxiliary wiring includes a part over the concave portion and a part over the non-concave portion, a top face of the part over the concave portion being concave with respect to a top face of the part over the non-concave portion.