LED Array Cell Structure for Phosphor Heat Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High power LED light-emitting device arrays face efficiency decreases due to heat generation from phosphor-coated or filled covers, leading to reduced light-conversion efficiency and die efficiency, along with issues like delamination and internal reflection losses.
Innovation Solution
A thermally conductive support member with a phosphor-coated or filled cover attached to its upper face, allowing heat transfer to a thermally conductive substrate, and proper heat dissipation design to prevent overheating, combined with individual cells in the substrate to control light characteristics and minimize cross-talk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phosphor-coated or filled covers are used in high power LED arrays, then light conversion is achieved, but heat generation reduces efficiency and causes delamination
Solution Approach 1:
The patent divides the LED array into individual cells separated by trenches, with each cell containing its own phosphor-coated support member. This segmentation isolates heat sources and prevents thermal accumulation that would otherwise reduce efficiency and cause delamination, while maintaining light conversion functionality in each cell.
Solution Approach 2:
The patent introduces thermally conductive substrate material and support members as intermediaries to facilitate heat transfer away from the phosphor-coated regions. These intermediary structures conduct heat from the phosphor conversion zones to the substrate, preventing temperature buildup that would harm efficiency and cause delamination.
2Illumination intensity
If multiple light-emitting dice are arranged in a package to increase intensity, then high light intensity is achieved, but heat dissipation becomes more difficult
Solution Approach 1:
The patent segments the high-power LED array into multiple individual cells, each containing one or more light-emitting dice. The trenches between cells act as thermal isolation barriers, allowing each cell to dissipate heat independently to the thermally conductive substrate, thereby maintaining low temperatures even as total light intensity increases.
Solution Approach 2:
The patent utilizes the substrate plane as an additional heat dissipation dimension by distributing multiple dice across the substrate surface rather than stacking them vertically. This spatial distribution increases the heat dissipation surface area and allows parallel heat flow paths to the substrate, effectively managing thermal load at high light intensities.
3Reliability
If individual cells with support members are used, then light extraction is improved, but device complexity increases
Solution Approach 1:
The patent designs the support members to serve multiple functions: they provide mechanical support for the phosphor coating, act as thermal conduction pathways to the substrate, and define the cell boundaries. This multi-functionality improves light extraction and heat management without proportionally increasing device complexity, as a single structural element accomplishes multiple tasks.
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 the light-emitting device array's efficiency by managing heat dissipation and reducing the adverse effects of phosphor-related temperature increases, improving reliability and light extraction while maintaining performance within specifications.
Implementation Method 1
A thermally conductive support member with a phosphor-coated or filled cover attached to its upper face, allowing heat transfer to a thermally conductive substrate
Data Source
AI summary
A light-emitting device and a method for manufacturing the light-emitting device is disclosed. Such a light-emitting device comprises a substrate, a plurality of cells disposed on the substrate, and a plurality of semiconductor dice, wherein each of the plurality of cells accommodates at least one of the plurality of dice. Each of the plurality of cells may be filled with an encapsulant, phosphor or a mixture of an encapsulant with phosphor to control light characteristics of the light-emitting device. In an alternative aspect, cells may be filled with an encapsulant, and comprise a transparent cover coated with or filled with phosphors to control light characteristics of the light-emitting device.