Interfacial studies of AlN-cordierite composite

• Main Author: Lum, Jun Ming.
• Other Authors: Oh Joo Tien
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/38718
• Institution: Nanyang Technological University

The growing momentum within the electronic industry towards miniaturisation increased circuit densities, higher speeds and more powerful chips has cause the industry to look for better packaging material that have good thermal conductivity for adequate heat dissipation and low dielectric constant for high speed performance chips A composite consisting of Aluminium Nitride and Cordierite could in theory meet all the above requirements. However, in reality, the thermal conductivity of the AlN-cordierite is found to be lower. Therefore it is important to find out what are the causes that affect the thermal conductivity of the AlN-cordierite composite. Thermal conductivity of composite is depended on how effectively phonon transport from one place to other within the composite network with minimum scattering. Therefore phase development, AlN-cordierite interface and microstructure will have an influence on the phonon transportation, thus affect the thermal conductivity of the composite. Investigation has found that the causes of low thermal conductivity are the formation of porous mullite due interfacial chemical reaction , the lattice mismatch due to the formation of stacking faults and polytypoids phase deposit at the AlN-cordierite interface and the formation of unsintered AlN which lead to decrease in densification and increase in porosity. The amount of mass fraction of the AIN added into cordierite will also alter the thermal conductivity. Adding less than 10 wt% AlN and more than 40 wt% will cause the drop in the thermal conductivity of the AlN-cordierite composite.