Aluminum Nitride (AlN) performance critically depends on purity, particularly the content of oxygen (O), carbon (C), and metal impurities (Fe, Na, etc.).
Oxygen impurities → Form Al₂O₃ or AlON phases, significantly reducing thermal conductivity (every 1% increase in oxygen decreases thermal conductivity by 10-20 W/(m·K)).
Metal impurities → Degrade carrier mobility in semiconductor devices, reducing performance.
Carbon impurities → Generate Al₄C₃ at high temperatures, causing material embrittlement.
Currently, commercial AlN powder typically has a purity of 99.5%-99.9% (oxygen content >0.5%), while high-end applications (e.g., semiconductor substrates) require oxygen content <0.1%, even <100ppm.
How to Achieve High-Purity Aluminum Nitride?
1. AlN Powder Purification Techniques
①Surface Modification (H₃PO₄ Treatment)
Phosphoric acid (H₃PO₄) forms a protective layer on AlN, inhibiting hydrolysis (reducing Al₂O₃ formation).
Advantage: Simple operation, suitable for industrial production.
Limitation: Cannot remove oxygen impurities inside the crystal lattice.
②High-Temperature Heat Treatment (2000-2200°C)
Heat treatment in a reducing atmosphere (H₂/N₂) to volatilize impurities.
Result: Oxygen content can be reduced to 220ppm, metal impurities <1ppm.
Challenge: Requires advanced equipment (tungsten crucible), AlN sublimation loss (~0.5-1%/h at 2200°C).
2. AlN Ceramic Purification Techniques
①NH₄F Sintering Additive
NH₄F decomposes into NH₃ & HF, reacting with Al₂O₃ to form volatile byproducts (e.g., AlF₃), reducing oxygen content.
Advantage: No new impurities introduced, enhances ceramic purity.
②High-Temperature Annealing
Heat treatment at 1800-1900°C to volatilize grain boundary phases, optimize microstructure, and improve thermal conductivity.
Future Trends: Higher Purity, Lower Cost
Advanced Purification Methods: Plasma-assisted purification, solvent extraction, CVD (Chemical Vapor Deposition) for ultra-pure AlN films.
Scalable Production: Optimized high-temperature processes to reduce AlN loss and costs.
Composite Materials: AlN-Graphene, AlN-SiC hybrid thermal materials for enhanced performance.
Conclusion: Aluminum Nitride – The Core Material for Future Technology
With the rapid growth of 5G, electric vehicles (EVs), deep-UV LEDs, and aerospace technologies, the demand for high-purity AlN will surge. Through advanced purification and sintering techniques, AlN will play a pivotal role in:
① Semiconductor devices (GaN-on-AlN, power electronics)
② High-power RF & 5G base stations
③EV power modules & thermal management
④Deep-UV LED substrates (UVC disinfection)
⑤Aerospace & extreme-environment applications
About Xiamen Juci Technology
Xiamen Juci Technology Co., Ltd. is a high-tech enterprise specializing in the research and development, production and sales of high-performance aluminum nitride (AlN) ceramic materials. The company is committed to providing high thermal conductivity and high purity aluminum nitride ceramic solutions for fields such as 5G communication, semiconductor packaging, power electronics, new energy vehicles, and aerospace. We can provide AlN substrates, structural components and functional devices of different specifications according to customer requirements.
Media Contact:
Xiamen Juci Technology Co., Ltd.
Phone: +86 592 7080230
Email: miki_huang@chinajuci.com
Website: www.jucialnglobal.com