Production of AIN Ceramics with High Thermal Conductivity

Production of AIN Ceramics with High Thermal Conductivity 

Aluminum nitride is an attractive material for microelectronics substrates due to its high thermal conductivity, good dielectric properties, and thermal expansion coefficient comparable with silicon. The thermal conductivity of approximately 300 W m is measured for pure single crystal of aluminum nitride. 

The main factor that prevents reaching maximum values of thermal conductivity in ceramics is oxygen impurity that is always present in nitride. Oxygen enters the aluminum nitride lattice and creates aluminum vacancies. This causes phonon scattering and thereby reduces the thermal conductivity [16]. 

Preparation of homogeneous powder mixture is a difficult task if powders are nanosized because such powders have the expressed tendency to agglomerate. 

This problem could be solved by mixing of powders in organic media with adding of a dispersant (oleic acid) and by using ultrasound treatment [13, 15]. 

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