LED Mesa Structure with Insulating Reflective Layer
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Solution Overview
Problem
Conventional light emitting diodes (LEDs) face limitations in improving reflectance and luminous efficacy due to the constraints of reflective electrode area and the difficulty in patterning distributed Bragg reflectors, which can lead to increased light loss and current leakage.
Innovation Solution
A light emitting diode design featuring an insulating reflection layer with a stacked structure of alternating refractive index layers, allowing for reduced reflective electrode area while maintaining high reflectivity, and a mesa structure with exposed portions to enhance light reflection and prevent current leakage, enabling direct mounting on a printed circuit board without packaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the area of the reflective electrode is increased to improve luminous efficacy, then light output is improved, but the distance between the reflective electrode and the periphery of the mesa structure decreases causing current leakage
Solution Approach 1:
The reflective electrode is segmented into a first reflective electrode and a second reflective electrode that are spatially separated. The first reflective electrode is positioned closer to the mesa structure periphery while the second reflective electrode is positioned farther away, allowing each electrode to serve different functions without causing current leakage. This segmentation enables the system to maintain high luminous efficacy while preventing current leakage by distributing the reflective function across multiple separated electrodes.
2Loss of energy
If a distributed Bragg reflector is used to improve light reflection, then reflectance is improved, but the structure becomes complex and difficult to pattern and form electrodes on
Solution Approach 1:
The patent extracts the essential reflective function from the complex distributed Bragg reflector structure and implements it through simpler metal reflective electrodes positioned on the mesa structure. Instead of using multiple alternating high and low refractive index layers that are difficult to pattern, the invention uses straightforward metal electrode deposition that achieves the desired light reflection while significantly reducing manufacturing complexity.
3Productivity
If the reflective electrode is positioned close to the mesa structure periphery to maximize area, then luminous efficacy is improved, but current leakage increases
Solution Approach 1:
The reflective electrode system is divided into multiple segmented electrodes with different positions relative to the mesa structure. The first reflective electrode can be positioned closer to maximize area utilization, while the second reflective electrode is positioned farther away to prevent current leakage. This segmentation allows the system to achieve both high luminous efficacy and current leakage prevention simultaneously.
Solution Approach 2:
Different regions of the reflective electrode system are assigned different qualities and positions. The first reflective electrode region is optimized for maximum area and light collection, while the second reflective electrode region is positioned to ensure electrical isolation and prevent current leakage. This local differentiation of electrode properties enables the system to optimize both luminous efficacy and reliability.
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
The solution improves reflectance and luminous efficacy by reducing light loss and preventing current leakage, while simplifying the manufacturing process and enhancing the reliability of the light emitting diode package.
Implementation Method 1
an insulating reflection layer with a stacked structure of alternating refractive index layers
Implementation Method 2
improves reflectance and luminous efficacy by reducing light loss
Data Source
AI summary
A light emitting diode having improved light efficiency and enhanced reflectivity of a device by forming an insulating reflective part on a reflective electrode formed on the upper surface of a mesa. A mesa exposing part is formed on the outer periphery and/or in the interior region of the reflective electrode to expose a predetermined area of the upper surface of the mesa such that reflection at the mesa exposing part is performed by the insulating reflective part.