LED Second Electrode Curved Extension for Uniform Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light-emitting diodes (LEDs) experience poor current spreading and non-uniform brightness due to current concentration around extension portions of the second electrode, leading to reduced brightness and reliability.
Innovation Solution
The LED design features a second electrode with extension portions whose projections on the substrate surface extend away from the lower edge toward the side edges, with an included angle between the central axis and the tangent line of the projection not exceeding 90 degrees, improving current spreading and antistatic ability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the second electrode includes extension portions that extend linearly away from the main portion, then the electrode structure is simple to manufacture, but current concentrates around the extension portions causing poor current spreading
Solution Approach 1:
The extension portions of the second electrode are designed with curved surfaces instead of linear extensions. The curved surface extends from the end of the main portion toward the side edge of the substrate, with the curvature radius increasing along the extension direction. This curved geometry distributes current more uniformly across the electrode surface, preventing current concentration at sharp edges while maintaining manufacturing feasibility.
2Reliability
If the extension portions extend toward the side edges, then current spreading is improved, but the included angle constraint limits design flexibility
Solution Approach 1:
The design specifies that the included angle between the central axis perpendicular to the bottom edge and the tangent line of any point on the projection of extension portions should not exceed 90 degrees, and this angle increases along the extension direction. This parameter constraint optimizes the geometric configuration to achieve uniform current distribution while preventing electrostatic breakdown, balancing design flexibility with performance requirements.
3Ease of manufacture
If conventional linear extension portions are used, then manufacturing is easier, but electrostatic discharge protection is insufficient
Solution Approach 1:
The curved surface of the extension portions with increasing curvature radius provides better electrostatic discharge protection compared to linear extensions. The curved geometry prevents sharp edges that concentrate electric fields, thereby enhancing ESD tolerance while maintaining ease of manufacture through standard electrode fabrication processes.
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 configuration enhances uniformity of current distribution, increases antistatic ability, and improves light-emitting efficiency and reliability by preventing electrostatic breakdown and ensuring consistent brightness.
Implementation Method 1
a current tends to concentrate around the extension portions 941, which might cause poor current spreading and overloading of the extension portions 41
Implementation Method 2
When an electrical current is applied to an LED, recombination of electrons and holes generated from predetermined p-type and n-type semiconductor layers occur so as to emit light with a desired wavelength
Data Source
AI summary
A light-emitting diode (LED) includes a substrate, an epitaxial structure, and first and second electrodes. The substrate has a surface with upper and lower edges, and two opposing side edges. The epitaxial structure is disposed on the surface. The first and second electrodes are disposed on the epitaxial structure. The second electrode includes a main portion and two extension portions. A projection of each of the extension portions on the surface extends in an extension direction away from the lower edge toward a corresponding one of the side edges in such a manner that an included angle between an central axis perpendicular to the bottom edge and a tangent line of any point on the projection of the extension portions on the surface is not greater than 90° and increases along the extension direction.