LED Chip Transmissive Layer Heat Management

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Solution Overview

Problem

Existing light emitting device packages face issues with wavelength conversion efficiency due to heat transfer from the light emitting device to the luminescence material layer, color temperature variation with viewing angles, and uneven luminescence material concentration, which affects the generation of white light.

Innovation Solution

A light emitting device chip design featuring a transmissive layer with low thermal conductivity and high light transmittance, interposed between the light emitting structure and the luminescence material layer, to restrict heat transfer and improve wavelength conversion efficiency, while a patterned luminescence material layer is used to control optical characteristics and light extraction efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the luminescence material is mixed with the encapsulating material and filled in the reflective cup, then the white light is formed by mixing the light from the light emitting device chip with the light colliding with the luminescence material, but the reflective cup must be provided in the package, increasing device complexity

Engineering Contradiction:
Improvewhite light formationVSAvoidreflective cup structure
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent combines the luminescence material layer with the light emitting device chip structure, integrating the wavelength conversion function directly into the chip rather than using a separate reflective cup structure. This merging eliminates the need for additional components while achieving the same white light generation effect.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light emitting device chip structure is designed to serve multiple functions: light generation, heat management, and wavelength conversion. By making the chip multi-functional, the patent eliminates the need for separate specialized components like the reflective cup, thereby reducing device complexity.

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

2Device complexity

If the light emitting device is adjacent to the luminescence material layer, then the structure is compact, but heat generated from the light emitting device is transferred to the luminescence material layer, degrading the wavelength conversion efficiency

Engineering Contradiction:
Improvecompact structureVSAvoidwavelength conversion efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent introduces an intermediate structure (the transmissive layer with specific thermal and optical properties) between the light emitting device and the luminescence material layer. This intermediary layer acts as a thermal barrier to reduce heat transfer while maintaining optical functionality, thus protecting the luminescence material from thermal degradation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies different material properties to different regions of the device structure. Specifically, the layer between the light emitting device and luminescence material is designed with low thermal conductivity and high light transmittance, creating local quality variations that optimize both thermal management and optical performance.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If particles of the luminescence material sink during the process, then the concentration of the luminescence material varies depending on the process time, but achieving uniform distribution requires additional process control

Engineering Contradiction:
Improvematerial distributionVSAvoidluminescence material concentration uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent uses a composite encapsulating material that combines the luminescence material particles with a matrix material having specific rheological properties. This composite formulation prevents particle sinking during the filling process while maintaining uniform concentration distribution, eliminating the need for complex process control measures.

Inventive Principle:
Principle #40Composite materials

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 enhances wavelength conversion efficiency, stabilizes color temperature across viewing angles, and improves light extraction efficiency, enabling the spontaneous generation of white light with consistent performance.

Implementation Method 1

a transmissive layer with low thermal conductivity and high light transmittance, interposed between the light emitting structure and the luminescence material layer, to restrict heat transfer

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

the white light is formed by mixing the light having a first wavelength generated from the light emitting device chip with the light colliding with the luminescence material and having a wavelength longer than the first wavelength

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP2346102B1Light emitting diode chip and package incorporating the same
Publication Date: 2020.03.04 LG INNOTEK CO LTD
  • EP2346102B1 patent drawingFigure 1~2
  • EP2346102B1 patent drawingFigure 3~4
  • EP2346102B1 patent drawingFigure 5~6

AI summary

Disclosed are a light emitting diode chip (100,102,103,104,200,202), a light emitting diode package (500), and a lighting system (1100,1200). The light emitting diode chip includes a light emitting structure (110) including a first conductive semiconductor layer (112), a second conductive semiconductor layer (116) and an active layer (114) interposed between the first and second conductive semiconductor layers; a transmittive layer (130) on the light emitting structure; and a luminescence material layer (140,143) on the transmittive layer, wherein the luminescence material layer includes a pattern, which does not expose the transmittive layer, partially exposes the transmittive layer or partially exposes the transmittive layer and the light emitting structure.