Abstract
It is necessary for encapsulants to have not only a coefficient of thermal expansion (CTE) suitable to IC devices and a low dielectric constant to reduce the device propagation delay, but also a high thermal conductivity to dissipate large amounts of heat from power-hungry, high-speed IC and high-density packages. Fillers such as silica have been mixed with polymers to improve their properties. Aluminum nitride (AlN) is considered as an alternative one, because it has a higher theoretical thermal conductivity of 320 W/mK, a compatible CTE with silicon chips and a low dielectric constant. Recently, we successfully obtained single-crystalline spherical AlN fillers. Furthermore, polymer composites filled with the spherical AlN showed excellent thermal conductivity (>8W/mK) as encapsulants for dissipating the heat generated in electronic devices.
