Metal Common Electrodes for Display Apparatus Ohmic Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of display panels with indium tin oxide (ITO) common electrodes is challenging due to their limited extensibility and toughness, leading to reduced yield rates and unstable light output from light-emitting diodes with different wavelengths connected to the same material electrodes.
Innovation Solution
The use of metal common electrodes with favorable extensibility and toughness, such as gold, germanium, nickel, or their alloys, in contact with a portion of the second type electrode of light-emitting devices to form an ohmic contact, while maintaining a specific contact area ratio to ensure efficient light output and current conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If indium tin oxide (ITO) is used as common electrode material, then stable and light transmissive properties are achieved, but extensibility and toughness are limited making manufacturing more difficult
Solution Approach 1:
The patent changes the material parameter of the common electrode from ITO to metal materials (such as aluminum, silver, or their alloys). This material substitution maintains electrical conductivity and light transmissivity while dramatically improving extensibility and toughness, thereby resolving the contradiction between reliability and ease of manufacture.
2Reliability
If ITO common electrodes are used, then light transmissive properties are maintained, but yield rates of the display panel are reduced
Solution Approach 1:
By changing the material parameter from ITO to metal common electrodes, the patent improves extensibility and toughness, making the manufacturing process more robust and less prone to defects. This material substitution directly addresses the low yield rate issue while preserving light transmissive properties.
3Ease of manufacture
If metal common electrodes are used, then extensibility and toughness are improved, but contact area ratio must be controlled to maintain light output efficiency
Solution Approach 1:
The patent applies local quality control by specifying that the metal common electrode contacts only a portion of the second type electrode, with the contact area ratio controlled at 0.3 or less. This localized contact approach maintains good electrical connection (ohmic contact) while preserving light output efficiency by limiting the electrode's impact on the light-emitting area.
4Reliability
If metal common electrodes with high work function interfaces are used, then ohmic contact efficiency is enhanced, but device complexity increases
Solution Approach 1:
The patent simplifies the device structure by using metal materials (aluminum, silver, or their alloys) as common electrodes, which inherently provide high work function interfaces for efficient ohmic contact. This material parameter change achieves good electrical contact without requiring additional complex interface engineering layers.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the efficiency of ohmic contact and maintains light output efficiency by using metal common electrodes with high work function interfaces, improving device properties and manufacturing yield rates.
Implementation Method 1
in contact with a portion of the second type electrode of each of the light-emitting devices to form an ohmic contact
Data Source
AI summary
A display apparatus includes a driving substrate, a plurality of light-emitting devices, and a plurality of metal common electrodes. The light-emitting devices are dispersedly disposed on the driving substrate, and each of the light-emitting devices includes an epitaxial structure and a first type electrode and a second type electrode disposed on the epitaxial structure. The metal common electrodes are dispersedly disposed on the driving substrate and in contact with a portion of the second type electrode of each of the light-emitting devices to form an ohmic contact.