LED Electrode Barrier Layer Blocks Diffusion

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Solution Overview

Problem

The reliability of semiconductor light emitting devices is compromised due to diffusion between the adhesive and bonding layers in the electrode, which degrades their adhesion and bonding strength, leading to reduced performance and lifespan.

Innovation Solution

Incorporating a barrier layer with grain boundaries containing interstitial elements between the adhesive and bonding layers to prevent diffusion, thereby maintaining the integrity of the electrode's adhesion and bonding strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a barrier layer with grain boundaries is introduced between adhesive and bonding layers, then diffusion prevention and reliability are improved, but device complexity increases

Engineering Contradiction:
Improveelectrode reliabilityVSAvoidelectrode structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A barrier layer is introduced as an intermediary component between the adhesive layer and bonding layer. This barrier layer contains grain boundaries with interstitial elements that act as diffusion barriers, preventing direct contact and material diffusion between the adhesive and bonding layers, thereby improving electrode reliability without requiring fundamental changes to the electrode architecture

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The barrier layer is constructed using composite material characteristics with grain boundaries containing interstitial elements. This composite structure combines different material phases and microstructural features to achieve superior diffusion resistance while maintaining structural integrity and functionality of the electrode assembly

Inventive Principle:
Principle #40Composite materials

2Device complexity

If the electrode structure is simplified without a barrier layer, then device complexity is reduced, but diffusion occurs between adhesive and bonding layers reducing adhesion strength

Engineering Contradiction:
Improveelectrode structure complexityVSAvoidadhesion strength
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The barrier layer serves as a mediating structure that physically separates the adhesive and bonding layers, preventing direct diffusion interfaces that would compromise adhesion strength. The grain boundaries with interstitial elements provide additional diffusion pathways control, ensuring long-term maintenance of bonding integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The barrier layer introduces localized microstructural features (grain boundaries with interstitial elements) at the critical interface region between adhesive and bonding layers. This local quality enhancement provides targeted diffusion prevention exactly where it is needed to maintain adhesion strength, without requiring modification of the entire electrode structure

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

The use of a barrier layer with interstitial elements effectively blocks diffusion between the adhesive and bonding layers, enhancing the reliability and longevity of the light emitting device by maintaining their functional integrity.

Implementation Method 1

a barrier layer disposed on the adhesive layer; and a bonding layer disposed on the barrier layer, and wherein the barrier layer comprises a plurality of grain boundaries, and each of the grain boundaries comprises interstitial elements

Methodology Applied
Scientific EffectDiffusion barrier: Diffusion Barrier

Data Source

PatentEP2722898B1Electrode for Light Emitting Diode
Publication Date: 2019.03.13 LG INNOTEK CO LTD
  • EP2722898B1 patent drawingFigure 1~2
  • EP2722898B1 patent drawingFigure 3
  • EP2722898B1 patent drawingFigure 4~5

AI summary

Disclosed is a light emitting device. The light emitting device includes a light emitting structure including a first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, and a second conductive semiconductor layer on the active layer; and an electrode on at least one of the first and second conductive semiconductor layers, wherein the electrode includes: an adhesive layer on the light emitting structure; a barrier layer on the adhesive layer; and a bonding layer on the barrier layer, and wherein the barrier layer comprises a plurality of grain boundaries, and each of the grain boundaries comprises interstitial elements.