Fabrication of highly water-resistant AlN particles with hybrid α-Al<sub>2</sub>O<sub>3</sub>/organic layers

Abstract

The water resistance of AlN particles was improved by surface coating with hybrid α-Al2O3/organic layers. To maintain thermal conductivity, the higher-thermal-conductivity α-Al2O3 layer was designed to cover most of the AlN surface, and the lower-thermal-conductivity organic layer was formed on the remaining area. Scanning electron microscopy, energy dispersive X-ray spectrometry and thermogravimetric analyses of the particles revealed that the small amount of organic layer was filling the cracks in the α-Al2O3 layer. The water resistant property was evaluated by a water immersion test. The pH of water dispersing the particles with hybrid layers was less than that of water dispersing the particles coated only with α-Al2O3 or organic layers, which indicated that the particles with hybrid layers had improved water resistance. The particles have applications in polymer composites for insulation in electronic devices which require improved reliability.