UV Light-Emitting Element Electrode Layout for Current Spreading
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Solution Overview
Problem
Light-emitting elements face reliability issues due to current concentration and heat generation at specific connection points, leading to potential damage and reduced performance, especially when emitting light in the ultraviolet region.
Innovation Solution
The design includes a semiconductor structure with a p-side electrode and n-side wiring layers, where the shortest distance between the p-side electrode and the second p-side connection portion is greater than the distance to the closest n-side connection portion, and the second p-side electrode is positioned to increase light extraction efficiency and reduce current concentration, using reflective metal layers and insulating films to manage heat and current distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the second p-side connection portion is positioned close to the first p-side electrode to reduce wiring length, then the device complexity is reduced, but current concentration and heat generation increase causing reliability deterioration
Solution Approach 1:
The patent introduces an intermediate protective structure (insulating film and/or semiconductor layer) between the first p-side electrode and the second p-side connection portion. This intermediary layer acts as a mediator that allows electrical connection while preventing direct current concentration and heat generation at the interface, thus resolving the contradiction between short wiring length and reliability.
2Reliability
If the second p-side electrode has wide coverage to reduce current concentration, then the reliability is improved, but the area occupied increases
Solution Approach 1:
The patent applies local quality by making the second p-side electrode have non-uniform coverage - wider in regions where current concentration needs to be reduced and more localized in regions where area conservation is prioritized. This allows the electrode to provide current distribution benefits only where needed, resolving the contradiction between reliability improvement and area occupation.
3Reliability
If the distance between first p-side electrode and second p-side connection portion is increased to reduce current concentration, then the reliability is improved, but the wiring length and device complexity increase
Solution Approach 1:
The patent uses an intermediate layer (insulating film and/or semiconductor layer) as a mediator that enables increased spacing between the first p-side electrode and second p-side connection portion without proportionally increasing wiring length. The intermediary structure allows current to flow through a longer path while maintaining compact overall device dimensions, thus resolving the contradiction between reliability improvement through increased spacing and device complexity.
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 the reliability of the light-emitting element by reducing current concentration and heat-related damage, maintaining performance even when emitting light in the ultraviolet region, and optimizing optical design for stronger light emission.
Implementation Method 1
maintaining a high reflectance for light extraction
Data Source
AI summary
A shortest distance between a first p-side electrode and a second p-side connection portion is greater than a shortest distance between the first p-side electrode and a closest one of first n-side connection portions most proximate to the first p-side electrode among a plurality of first n-side connection portions in the plan view. The second p-side electrode is located at least in a region between the first p-side electrode and the closest one of the first n-side connection portions in the plan view.