Enhanced thermal conductivity of low-temperature sintered borosilicate glass-AlN composites with beta-Si3N4 whiskers

The effects of beta-Si3N4 whiskers on the thermal conductivity of low-temperature sintered borosilicate glass-AlN composites were systematically investigated. The thermal conductivity of borosilicate glass AN ceramic composite was increased from 11.9 to 18.8 W/m K by incorporating 14 vol% beta-Si3N4 whiskers, and high flexural strength up to 226 MPa were achieved along with low relative dielectric constant of 6.5 and dielectric loss of 0.16% at 1 MHz. Microstructure characterization and percolation model analysis indicated that thermal percolation network formation in the ceramic composites led to the high thermal conductivity. The crystallization of the borosilicate microcrystal glass also contributed to the enhancement of thermal conductivity. Such ceramic composites with low sintering temperature and high thermal conductivity might be a promising material for electronic packaging applications.