Integrated HFET LED Driver Circuit for Low Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional LED driver circuits are separated from LEDs, leading to voltage drops due to wiring resistance and potential damage from inductance, reducing energy efficiency and reliability, especially at high currents.

Innovation Solution

Integration of a heterostructure field-effect transistor (HFET) or thyristor driver circuit directly with the LED structure, using epitaxial growth techniques to minimize or eliminate resistance and inductance, with multi-quantum-well active regions and conductive materials for efficient current control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If LED driver circuit is separated from LED device, then ease of manufacture and independent optimization are improved, but voltage drop due to wiring resistance increases and energy efficiency deteriorates

Engineering Contradiction:

Improveease of manufactureVSAvoidenergy efficiency

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent merges the LED driver circuit with the LED device by integrating the driver circuit onto the same substrate as the LED structure. This co-location eliminates the need for separate wiring connections, thereby removing the source of resistive voltage drops while maintaining manufacturing simplicity through unified fabrication processes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces an intermediate layer or structure that directly couples the driver circuit output to the LED input without requiring external wiring. This intermediary connection minimizes the resistive path between driver and LED, reducing voltage drop while allowing independent optimization of each component during design.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If LED driver circuit is separated from LED device, then ease of manufacture and independent optimization are improved, but inductance in wiring causes damage and reliability deteriorates

Engineering Contradiction:

Improveease of manufactureVSAvoidreliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent merges the LED driver circuit with the LED device by integrating the driver circuit onto the same substrate as the LED structure. This co-location eliminates the need for separate wiring connections, thereby removing the source of inductance that causes voltage spikes during current transitions, while maintaining manufacturing simplicity through unified fabrication processes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces an intermediate layer or structure that directly couples the driver circuit output to the LED input without requiring external wiring. This intermediary connection minimizes the inductive path between driver and LED, preventing voltage spike damage during high current operation while allowing independent optimization of each component during design.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of energy

If integration is implemented, then resistance and inductance are reduced and energy efficiency is improved, but device complexity increases

Engineering Contradiction:

Improveenergy efficiencyVSAvoiddevice complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent designs the substrate to serve multiple functions simultaneously: it acts as both the mechanical support for the LED structure and the electrical interconnection medium between the driver circuit and LED. This multi-functionality reduces the need for separate components and interconnections, thereby lowering overall device complexity while achieving low resistance and inductance for high energy efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the physical parameters of the integration architecture by reducing the distance and cross-sectional area of current paths between driver circuit and LED. This parameter optimization minimizes resistance and inductance values, improving energy efficiency while the unified substrate architecture keeps the overall device structure simple and manageable.

Inventive Principle:

Principle #35Parameter changes

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 integration results in robust, high-power LED devices with reduced series resistance and inductance, enabling efficient operation under various conditions with low failure rates and improved energy efficiency for solid-state lighting applications.

Implementation Method 1

The LED structure can include a multi-quantum-well (MQW) active region

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

The HFET driver circuit can include an epi-layer disposed over a substrate with a first portion of the epi-layer configured to form a heterostructure

Methodology Applied

Scientific EffectField effect: Electric Field

Implementation Method 3

using epitaxial growth techniques to minimize or eliminate resistance and inductance

Methodology Applied

Scientific EffectEpitaxy: Epitaxy

Data Source

PatentUS8866125B2Integration of LED driver circuit with LED

Publication Date: 2014.10.21 STC UNM

AI summary

Various embodiments provide materials and methods for integrating exemplary heterostructure field-effect transistor (HFET) driver circuit or thyristor driver circuit with LED structures to reduce or eliminate resistance and/or inductance associated with their conventional connections.