LED Protective Layer Schottky Contact ESD Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional light emitting diodes (LEDs) are vulnerable to damage from excessive voltage due to electrostatic discharge (ESD) or surge effects, which can cause current to flow through the protective layer instead of the light emitting structure, potentially damaging the device and reducing its lifespan.

Innovation Solution

A light emitting device structure with a protective layer that comes into Schottky contact with the electrode layer and first electrode, allowing current to flow through the protective layer during excessive voltage events, thereby protecting the light emitting structure and improving withstanding voltage characteristics without reducing the light emitting area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the protective layer is made more conductive to allow current diversion during voltage surges, then the voltage withstand capability is improved, but the light emitting area may be reduced or compromised

Engineering Contradiction:
Improvevoltage withstand capabilityVSAvoidlight emitting area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The protective layer is segmented into different regions: a first region that contacts the electrode layer and provides Schottky contact for voltage protection, and a second region that forms the light emitting area. This segmentation allows each region to have optimized properties - the first region for electrical protection and the second region for light emission - thereby resolving the contradiction between voltage withstand capability and light emitting area.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the protective layer are given different local qualities: the first region is designed with specific conductivity and Schottky contact properties for voltage surge protection, while the second region is optimized for light emission. This local differentiation allows the protective layer to simultaneously provide both protection and light emission functions without compromising either, thus resolving the technical contradiction.

Inventive Principle:
Principle #3Local quality

2Reliability

If a Schottky contact structure is added between the protective layer and electrode layer, then the voltage surge protection is improved, but the device complexity increases

Engineering Contradiction:
Improveprotection against electrostatic dischargeVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protective layer is merged with the light emitting structure such that it serves dual functions: as a protective layer providing Schottky contact for voltage surge protection and as part of the light emitting structure. This merging eliminates the need for separate protective components, thereby improving reliability against electrostatic discharge while minimizing the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The protective layer is designed to perform multiple functions simultaneously: it provides Schottky contact for voltage protection, forms part of the light emitting area, and maintains structural integrity. This multi-functionality reduces the need for additional components and simplifies the overall device structure while enhancing protection capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If the protective layer is designed to contact both the electrode layer and first electrode, then the current diversion path is improved during surges, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecurrent diversion capabilityVSAvoidalignment precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The protective layer is formed to extend beyond the light emitting area in advance, ensuring that it contacts both the electrode layer and first electrode before subsequent manufacturing steps. This preliminary positioning ensures proper alignment and current diversion paths are established early in the manufacturing process, reducing the stringency of alignment precision requirements in later steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The protective layer acts as an intermediary element that naturally bridges the electrode layer and first electrode. Its extended structure serves as a built-in alignment reference and connection medium, facilitating proper contact between components and reducing the need for high-precision alignment during assembly, thereby improving current diversion capability while managing manufacturing precision requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively prevents damage to the light emitting structure by allowing current to divert through the protective layer during voltage surges, enhancing the device's voltage withstand capability while maintaining the light emitting area intact.

Implementation Method 1

the protective layer comes into Schottky contact with at least one of the electrode layer and the first electrode

Methodology Applied
Scientific EffectSchottky contact: Conduction (electrical)

Data Source

PatentEP2362450B1Light emitting diode, light emitting diode package
Publication Date: 2018.07.18 LG INNOTEK CO LTD
  • EP2362450B1 patent drawingFigure 1~3
  • EP2362450B1 patent drawingFigure 4~5
  • EP2362450B1 patent drawingFigure 6~7

AI summary

A light emitting diode (100) device according to the embodiment includes a substrate (110); a protective layer (120) on the substrate; an electrode layer (160) on the protective layer; a light emitting structure (145) disposed on the electrode layer to generate light and provided with a first semiconductor layer (130), an active layer (140) under the first semiconductor layer, and a second conductive semiconductor layer (150) under the active layer; and a first electrode (170) having a first end disposed on a top surface of the light emitting structure (145) and a second end disposed on the protective layer (120). The protective layer (120) comes into Schottky contact with at least one of the electrode layer (160) and the first electrode (170).