LED Assembly Thermal Management via Segmented Insulating Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LED packages face challenges with heat dissipation and thermal resistance due to substrates with low thermal conductivity and encapsulant materials that expand, leading to delamination and stress issues.
Innovation Solution
The implementation of thermally conductive layers and vias, including copper layers, to enhance heat spreading and thermal conductivity, with electrically isolated electrodes and conductive traces for improved thermal and mechanical coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If substrates with low thermal conductivity are used in LED packages, then electrical insulation is provided, but heat dissipation is poor and thermal resistance increases
Solution Approach 1:
The substrate is divided into functionally distinct regions: electrically insulating areas provide electrical isolation, while thermally conductive regions (with high thermal conductivity material) provide heat dissipation pathways. This segmentation allows each region to optimize for its specific function without compromising the other.
Solution Approach 2:
Different regions of the substrate are assigned different material properties: areas requiring electrical insulation use insulating materials, while areas requiring heat dissipation use thermally conductive materials. This local differentiation of material quality enables simultaneous achievement of electrical isolation and thermal management.
2Illumination intensity
If encapsulant materials with high coefficients of thermal expansion are used, then light transmission is achieved, but thermal expansion causes lens movement, delamination, and stress
Solution Approach 1:
The patent modifies the thermal expansion parameter of the encapsulant material by selecting materials with lower coefficients of thermal expansion. This parameter change reduces the magnitude of thermal expansion and contraction during temperature cycling, thereby preventing lens movement, delamination, and stress-related failures while maintaining light transmission properties.
3Illumination intensity
If reflective cups are used to direct light upward, then light direction is improved, but light absorption by the cup and mechanical complexity increase
Solution Approach 1:
The substrate integrates multiple functions that were previously performed by separate components: it provides electrical insulation, heat dissipation, mechanical support, and light reflection. By merging these functions into a single multi-functional substrate, the patent eliminates the need for separate reflective cups and reduces overall device complexity while maintaining light direction control.
Solution Approach 2:
The substrate is designed as a universal component that performs multiple functions simultaneously: electrical isolation, thermal management, mechanical support, and optical reflection. This multi-functionality reduces the number of discrete parts needed in the LED package, simplifying the overall structure.
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 solution effectively reduces thermal resistance and stress in LED packages, allowing for more efficient heat dissipation and improved robustness by using thermally conductive layers and vias to manage heat and mechanical stress.
Implementation Method 1
a first thermally conductive layer over the first surface of the electrically insulating substrate, and a second thermally conductive layer over the second surface of the electrically insulating substrate
Implementation Method 2
a plurality of thermally conductive vias thermally coupled between the first and second thermally conductive layers
Implementation Method 3
an electrically insulating substrate having opposing first and second surfaces
Data Source
Figure 1A~1C
Figure 1D~1E
Figure 2~3
AI summary
A. light emitting device (LED) assembly may include an electrically insulating substrate (100a-k) and a thermally conductive layer (112a-k) on a surface (105a-k) of the insulating substrate (100a-k). A light emitting device (114a-k) may be on the thermally conductive layer (112a-k) so that the thermally conductive layer (112a-k) is between the light emitting device (114a-k) and the electrically insulating substrate (100a-k). Moreover, the thermally conductive layer may extend beyond an edge of the light emitting device (114a-k) in at least one direction a distance greater than half of a width of the light emitting device (114a-k).