Nitride Semiconductor Laser Thermal Management via Segmented Electrode

Solution Overview

Problem

Conventional nitride semiconductor laser devices face challenges in heat release due to the insulating portion and p-electrode configuration, leading to high temperatures and potential metal diffusion in the connecting electrode, which limits the heat releasing property and affects threshold current and light output.

Innovation Solution

A nitride semiconductor laser device with a thermally conductive portion disposed in contact with the p-type layer, electrically insulated from the p-electrode, allowing for direct heat release and improved thermal management, using materials like Ag/Ni or Cu/TiN stacks, and optionally buried or forming protrusions for enhanced contact area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an insulating portion and p-electrode configuration is used, then electrical insulation is achieved, but heat release is hindered leading to high temperatures

Engineering Contradiction:

Improveelectrical insulationVSAvoidheat release

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The device separates the electrical function (p-electrode) from the thermal management function (thermally conductive portion). The p-electrode provides electrical contact while the thermally conductive portion, disposed in a different region, provides heat dissipation. This functional segmentation allows independent optimization of electrical and thermal performance without interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The thermally conductive portion acts as an intermediary heat transfer element between the p-type layer and the heat sink. It provides a dedicated thermal pathway that does not interfere with the electrical function of the p-electrode, effectively mediating the heat transfer process while maintaining electrical insulation where needed.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If conventional electrode configuration is used, then device simplicity is maintained, but metal diffusion occurs limiting heat releasing property

Engineering Contradiction:

Improveelectrode configurationVSAvoidheat releasing property

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The device separates the electrical function (p-electrode) from the thermal management function (thermally conductive portion). The p-electrode provides electrical contact while the thermally conductive portion, disposed in a different region, provides heat dissipation. This functional segmentation allows independent optimization of electrical and thermal performance without interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The thermally conductive portion acts as an intermediary heat transfer element between the p-type layer and the heat sink. It provides a dedicated thermal pathway that does not interfere with the electrical function of the p-electrode, effectively mediating the heat transfer process while maintaining electrical insulation where needed.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Temperature

If high thermal conductivity materials are used, then heat dissipation is improved, but device structure becomes more complex

Engineering Contradiction:

Improveheat dissipationVSAvoidstructure

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

High thermal conductivity materials are used specifically in the thermally conductive portion where heat dissipation is critical, while other parts of the device maintain their original structure. This localized application of special materials optimizes thermal performance without unnecessarily complicating the overall device architecture.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The thermally conductive portion acts as an intermediary heat transfer element between the p-type layer and the heat sink. It provides a dedicated thermal pathway that does not interfere with the electrical function of the p-electrode, effectively mediating the heat transfer process while maintaining electrical insulation where needed.

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

This configuration enhances heat release, reduces threshold current, and improves light output by allowing the use of high thermal conductivity materials and efficient heat dissipation, addressing the limitations of conventional devices.

Implementation Method 1

a thermally conductive portion disposed in contact with the p-type layer in a region which is different from the region where the p-electrode is connected

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS8711892B2Nitride semiconductor laser device

Publication Date: 2014.04.29 NICHIA CORP

AI summary

A nitride semiconductor laser device includes: a stack, the stack including an n-type layer and a p-type layer each including a nitride semiconductor; an n-electrode electrically coupled to the n-type layer; a p-electrode electrically coupled to the p-type layer; and a thermally conductive portion disposed in contact with the p-type layer in a region which is different from the region where the p-electrode is connected, wherein the thermally conductive portion is electrically insulated from the p-electrode. Manufacturing steps specific to nitride semiconductors are employed to form the device. An optical apparatus, such as an optical disc device, a display device, or a lighting device includes such a nitride laser device and depends its functions thereto.