LED Packaging Thermal Management via Intermediary Shielding

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Solution Overview

Problem

The challenge is to develop a packaging technology that effectively manages thermal influences between temperature-sensitive LEDs and integrated circuits (ICs) in compact LED packages, particularly when operating at high temperatures, as existing solutions fail to maintain ICs within their working temperature specifications while ensuring efficient heat dissipation.

Innovation Solution

The solution involves a device design where the most temperature-sensitive LED is positioned between less temperature-sensitive LEDs and the IC, with additional features such as varied mounting areas, thermal shielding, and thermal conductors to separate and dissipate heat effectively, ensuring the IC operates within its temperature specifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If multiple LEDs are packaged in a narrow spaced ultra-thin package to achieve miniaturization, then the package size is reduced and etendue is improved, but thermal influence between LEDs increases and temperature-sensitive LEDs are damaged

Engineering Contradiction:
Improvepackage sizeVSAvoidthermal influence between LEDs
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The patent divides the package into distinct thermal zones by introducing thermal isolation structures (trenches or air gaps) between LEDs. This segmentation creates separate thermal management regions, allowing each LED to operate at its optimal temperature while maintaining compact overall package dimensions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces thermal isolation structures (trenches filled with low thermal conductivity material or air gaps) as intermediary elements between LEDs. These intermediaries act as thermal barriers that reduce heat transfer between adjacent LEDs, protecting temperature-sensitive LEDs while maintaining close spacing for miniaturization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If LEDs are driven at high current to increase light output, then luminous intensity is improved, but temperature increases and damages temperature-sensitive LEDs

Engineering Contradiction:
Improveluminous intensityVSAvoidoperating temperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent extracts heat away from temperature-sensitive LEDs by providing dedicated thermal management paths. Heat generated by high-current LEDs is conducted through specialized thermal vias and heat sinks, separating the heat extraction path from the sensitive LED regions, thereby enabling high current operation without thermal damage.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different thermal management properties to different regions of the package. High-power LEDs have enhanced thermal conduction paths with high thermal conductivity materials, while temperature-sensitive LEDs are surrounded by low thermal conductivity barriers, creating localized thermal zones optimized for each LED type.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If an IC is integrated into the LED package to achieve functional integration, then device functionality is improved, but the IC is exposed to high temperatures beyond its working specifications

Engineering Contradiction:
Improvefunctional integrationVSAvoidambient temperature for IC
Core Design Contradiction:
Adaptability or versatilityVSTemperature

Solution Approach 1:

The patent introduces thermal shielding structures (trenches or barriers) as intermediaries between high-power LEDs and the IC. These shields block thermal radiation and conduction paths from LEDs to the IC, creating a thermal protection zone that allows the IC to operate within its specified temperature range while maintaining close integration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses three-dimensional thermal management structures such as deep trenches or layered thermal barriers to separate the IC thermally from LEDs. By utilizing vertical dimension (depth of trenches) rather than only horizontal spacing, the IC can be positioned close to LEDs for electrical integration while maintaining thermal isolation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Temperature

If thermal isolation structures are added to separate LEDs thermally, then thermal influence is reduced, but device complexity increases

Engineering Contradiction:
Improvethermal separation between LEDsVSAvoidpackage structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the thermal isolation structures. The same trenches or barriers that provide thermal isolation also serve as mechanical support structures, light extraction pathways, and stress relief features. This merging reduces the need for additional separate components, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The thermal management structures are designed to perform multiple functions simultaneously: thermal isolation, mechanical support, electrical insulation, and light management. This multi-functionality reduces the overall component count and structural complexity compared to having separate dedicated structures for each function.

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

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 approach effectively protects the IC from high temperatures by optimizing heat dissipation and thermal decoupling, allowing for reliable operation of LEDs at high temperatures while keeping the IC at a lower temperature, thus extending its lifespan and maintaining performance.

Implementation Method 1

A most temperature sensitive light emitting diode of the plurality of light emitting diodes is located between less temperature sensitive light emitting diodes of the plurality of light emitting diodes and the at least one integrated circuit

Methodology Applied
Scientific EffectThermal shielding: Thermal Insulation

Implementation Method 2

heat generated by each light emitting diode may be efficiently dissipated

Methodology Applied
Scientific EffectHeat dissipation: Convection

Implementation Method 3

heat generated by each light emitting diode may be efficiently dissipated

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2394300B1Improved packaging for LED combinations
Publication Date: 2018.08.15 SIGNIFY HOLDING BV
  • EP2394300B1 patent drawingFigure 1
  • EP2394300B1 patent drawingFigure 2
  • EP2394300B1 patent drawingFigure 3

AI summary

In summary, the present invention relates to a device, a system, a method and a computer program enabling a thermally improved packaging of a plurality of light emitting diodes (110, 112, 114) and at least one integrated circuit (116). A most temperature sensitive light emitting diode (110) of the plurality of light emitting diodes is located between less temperature sensitive light emitting diodes (112, 114) of the plurality of light emitting diodes and the at least one integrated circuit. Further, various additional measures such as e.g. varying at least one mounting area (102, 104, 106) of at least one light emitting diode, providing at least one thermal shielding (118), etc. can be taken in order to thermally optimize the packaging.