LED Electrode Layout for Current Spreading and Flip-Chip Reliability
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Solution Overview
Problem
Conventional light-emitting diodes (LEDs) face challenges in current spreading and heat dissipation, leading to potential line breakage when forming flip-chip structures, which affects the yield rate of optoelectronic devices.
Innovation Solution
The optoelectronic device features a semiconductor stack with a specific electrode pattern design, including multiple conductive type electrodes and insulating layers, optimized for current spreading and reduced height differences between electrodes to minimize line breakage during flip-chip formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrode patterns are used in LEDs, then the structure is simple, but current spreading is poor and line breakage occurs during flip-chip formation
Solution Approach 1:
The electrode pattern is divided into multiple segments including a first electrode pattern on the first semiconductor layer, a second electrode pattern on the second semiconductor layer, and a third electrode pattern on the insulating layer. This segmentation allows current to spread through multiple paths, reducing line breakage probability while managing the complexity through systematic distribution of electrode functions.
Solution Approach 2:
The electrode structure extends from a single-plane configuration to a multi-layer three-dimensional arrangement. The first electrode pattern is positioned on the first semiconductor layer, the second electrode pattern on the second semiconductor layer, and the third electrode pattern on the insulating layer, creating vertical stacking that enhances current spreading in multiple dimensions and reduces line breakage.
2Temperature
If conventional electrode designs are used, then manufacturing is simple, but heat dissipation is insufficient
Solution Approach 1:
The heat dissipation function is segmented across multiple electrode patterns and layers. The first electrode pattern contacts the first semiconductor layer, the second electrode pattern contacts the second semiconductor layer, and the third electrode pattern provides additional thermal pathways through the insulating layer, creating multiple heat dissipation channels that improve thermal management.
Solution Approach 2:
The electrode structure utilizes composite material arrangements with conductive electrode patterns positioned on semiconductor layers and insulating layers with specific dielectric properties. This composite structure optimizes both electrical connectivity and thermal dissipation while maintaining manufacturability through established semiconductor fabrication processes.
3Reliability
If electrode height differences are large, then electrical connection is achieved, but line breakage probability increases during flip-chip formation
Solution Approach 1:
The electrode structure transitions from a single-plane configuration to a multi-layer vertical arrangement. By distributing electrode patterns across different vertical levels (first semiconductor layer, second semiconductor layer, and insulating layer), the design reduces height differences within each layer while maintaining effective electrical connections through the stacked configuration.
Solution Approach 2:
Each electrode pattern is optimized for its specific location and function. The first electrode pattern is designed for contact with the first semiconductor layer, the second electrode pattern for the second semiconductor layer, and the third electrode pattern for the insulating layer, with each pattern's geometry and dimensions tailored to its local electrical and mechanical requirements.
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 electrode pattern design enhances current spreading and reduces the probability of line breakage, thereby improving the yield rate of optoelectronic devices by ensuring efficient electrical connections and heat dissipation.
Implementation Method 1
a third electrode formed on the first insulating layer and including a first extended portion and a second extended portion, wherein the first extended portion is electrically connected to the first semiconductor layer through the first group of the first openings, the second extended portion is electrically connected to the first semiconductor layer through the second group of the first openings
Implementation Method 2
The lighting theory of light-emitting diodes (LEDs) is to transform electrical energy to optical energy by applying electrical current to the LED and injecting electrons and holes to the active layer, where the electrons and holes recombine to emit light
Data Source
AI summary
An optoelectronic device includes a first semiconductor layer, a second semiconductor layer and an active layer between the first semiconductor layer and the second semiconductor layer; a first insulating layer on the second semiconductor layer and including a plurality of first openings exposing the first semiconductor layer, wherein the first openings include a first group and a second group; a third electrode on the first insulating layer and including a first extended portion and a second extended portion, wherein the first extended portion and the second extended portion are respectively electrically connected to the first semiconductor layer through the first group of the first openings and the second group of the first openings, and wherein the number of the first group of the first openings is different from the number of the second group of the first openings; and a plurality of fourth electrodes on the second insulating layer and electrically connected to the second semiconductor layer, wherein in a top view of the optoelectronic device, the first extended portion is located between the fourth electrodes.