Inorganic White LED Chip Packaging for Heat and Color Stability
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Solution Overview
Problem
Conventional LED packaging using organic materials suffers from poor heat dissipation, leading to light attenuation, color shift, and shortened lifetime due to inadequate thermal conductivity, and existing inorganic packaging solutions face challenges with thermal bonding and defect issues.
Innovation Solution
A white LED chip packaged with an inorganic material, utilizing a single crystal substrate and a fluorescent transparent ceramic or crystal layer, along with a bonding layer, such as a metal elementary substance, sintered interface, or gluing layer, to enhance thermal stability and light-emitting efficiency, and improve packaging reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If organic packaging materials (epoxy resin or silica gel) are used to package YAG:Ce fluorescent powder, then the packaging process is simple and cost-effective, but the heat dissipation performance is poor leading to light attenuation, color shift, and shortened lifetime
Solution Approach 1:
The patent changes the material parameter from organic to inorganic, specifically using transparent ceramic materials with superior thermal conductivity properties. This parameter change enables effective heat dissipation while maintaining packaging functionality, resolving the contradiction between ease of manufacture and reliability by accepting increased manufacturing complexity for significant performance improvement
Solution Approach 2:
The patent employs composite material structures combining transparent ceramic materials with fluorescent powder particles. This composite approach leverages the high thermal conductivity of inorganic ceramics while incorporating the light-emitting properties of fluorescent powders, achieving both heat dissipation and light emission functions simultaneously
2Reliability
If inorganic transparent ceramic materials are used for LED packaging, then thermal conductivity and thermal stability are improved, but the manufacturing process becomes more complex with challenges in thermal bonding and defect control
Solution Approach 1:
The patent introduces intermediary bonding layers between the transparent ceramic packaging and LED chip to facilitate thermal bonding. These intermediary materials serve as mediators that enable reliable bonding while managing thermal expansion differences and bonding temperature requirements, thus reducing the overall process complexity
Solution Approach 2:
The patent applies preliminary actions by pre-treating surfaces, pre-positioning fluorescent powder particles, and preparing bonding interfaces before final assembly. These preliminary steps ensure proper alignment and reduce defects during the bonding process, simplifying the overall manufacturing complexity
3Productivity
If COB packaging structure with multiple LED chips is used, then light output and luminous efficiency are improved, but wire breakage risk increases and light color consistency becomes difficult to ensure
Solution Approach 1:
The patent extracts and eliminates the wire bonding step from the COB packaging process by using direct bonding of LED chips to the substrate. This removal of the wire connection element eliminates the associated reliability issues while maintaining high luminous flux output through direct chip-to-substrate thermal and electrical contact
4Productivity
If multiple fluorescent powder dispensing processes are used in COB packaging, then light output is enhanced, but light and color consistency becomes difficult to ensure
Solution Approach 1:
The patent merges the fluorescent powder application process into a single integrated step rather than multiple separate dispensing operations. By combining all fluorescent materials into one unified packaging layer, the patent ensures uniform distribution and consistent optical properties across the entire LED module, maintaining high luminous flux while achieving excellent color consistency
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 achieves improved thermal stability, reduced light attenuation, and consistent color output, resulting in high light-emitting efficiency and extended lifespan of LED devices, suitable for high-power applications.
Implementation Method 1
A white LED chip packaged in an inorganic material... the inorganic material packaging layer is configured to package the LED chip wafer... achieve improved thermal stability
Implementation Method 2
the inorganic material packaging layer comprises a fluorescent transparent ceramic sheet or a fluorescent crystal sheet... consistent color output... high light-emitting efficiency
Data Source
AI summary
A white light LED chip packaged in inorganic material, a device, a preparation method therefor, and an application thereof are provided. The white light LED chip includes an LED chip wafer, an inorganic material packaging layer and a single crystal substrate. The LED chip wafer has at least one flip or vertical LED chip. The inorganic material packaging layer packages the LED chip wafer. The inorganic material packaging layer has a fluorescent transparent ceramic piece or a fluorescent crystal piece.