Light Emitting Device Current Distribution via Segmented Structures

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Solution Overview

Problem

Light emitting devices face issues with current concentration and electrical reliability, particularly in preventing hotspots that can lead to reduced efficiency and lifespan.

Innovation Solution

The design incorporates a conductive support member with first and second light emitting structures, channel layers acting as etching stoppers, and connection parts that distribute power to prevent current concentration, along with insulating layers and reflective layers to enhance electrical reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional light emitting device structures are used, then manufacturing is simpler, but current concentration occurs leading to reduced electrical reliability

Engineering Contradiction:
Improveelectrical reliabilityVSAvoiddevice structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The device is divided into multiple light emitting structures (first and second light emitting structures) with separate active layers (first active layer and second active layer) that are independently surrounded by channel layers. This segmentation distributes the current flow across multiple regions, preventing current concentration in a single active layer and thereby improving electrical reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Channel layers are introduced as intermediary structures between the light emitting structures and the connection parts. These channel layers act as etching stoppers during isolation processing and provide a controlled interface for electrical connection, enabling reliable current distribution without direct contact between connection parts and active layers.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of moving object

If current concentration is not prevented, then device structure remains simple, but hotspots form reducing efficiency and lifespan

Engineering Contradiction:
Improvedevice lifespanVSAvoidstructure complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

Multiple light emitting structures with separate active layers are implemented, each surrounded by its own channel layer. This segmentation distributes the electrical current across multiple emission regions, preventing hotspot formation in any single area and thereby extending device lifespan without requiring complex external cooling or current management systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The channel layers are specifically positioned to surround only the active layers and lower portions of the light emitting structures, providing localized current distribution and protection exactly where needed. This localized approach prevents hotspots at the critical active layer interfaces while maintaining overall structural efficiency.

Inventive Principle:
Principle #3Local quality

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 effectively prevents current concentration and improves electrical reliability, leading to increased light extraction and extended device lifespan.

Implementation Method 1

The LED converts electrical signals into the form of light such as infra-red light, ultra-violet light, and visible light by using the characteristic of a compound semiconductor

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

a channel layer around lower portions of the first and second light emitting structures, the channel layer being an etching stopper when an isolation processing is performed with respect to the first and second light emitting structures

Methodology Applied
Scientific EffectEtching stopper:

Implementation Method 3

an electric power is supplied to the first and second light emitting structures through the conductive support member and the third connection part

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2706572B1Light emitting device
Publication Date: 2020.05.20 LG INNOTEK CO LTD
  • EP2706572B1 patent drawingFigure 1~2
  • EP2706572B1 patent drawingFigure 3~4
  • EP2706572B1 patent drawingFigure 5

AI summary

A light emitting device includes a conductive support member (70); a first light emitting structure (10) on the conductive support member, the first light emitting structure including a first conductive first semiconductor layer (11), a first active layer (12) under the first conductive first semiconductor layer, and a second conductive second semiconductor layer (13) under the first active layer; a second light emitting structure (20) on the conductive support member, the second light emitting structure including a first conductive third semiconductor layer (21), a second active layer (22) under the first conductive third semiconductor layer, and a second conductive fourth semiconductor layer (23) under the second active layer; a channel layer (30) around lower portions of the first and second light emitting structures; a first electrode (80) electrically connected to the first conductive first semiconductor layer; a second electrode (83) electrically connected to the second conductive second semiconductor layer; a third electrode (85) electrically connected to the first conductive third semiconductor layer; a fourth electrode (87) electrically connected to the second conductive fourth semiconductor layer; a first connection part (90) electrically connected to the first electrode and the conductive support member; a second connection part (95) electrically connected to the second and third electrodes; and a third connection part (97) electrically connected to the fourth electrode and having one end provided on the channel layer.