Morphology of thick film metallization on aluminum nitride ceramics and composition of interface layer.

Surface metallization of aluminum nitride is performed by a reactively thick film method. A layer of copper film is deposited on the surface of AlN ceramics. The morphology and composition of the metalized copper layer on ceramic substrate were investigated via scanning electron microscope (SEM) and X-ray diffraction (XRD). The interface layer between copper film and AlN substrate was examined through SEM, XRD and EDS. Reaction phases, Cu 2 O and intermediate phases (CuAlO 2 and CuAl 2 O 4 ), were detected at the interface layer. Subsequently, the formation process of these phases at the interface layer was discussed. And consequently, the relation within reaction phases and bonding strength was observed. Reaction phases play a key role in increasing bonding strength. The effect of these phases such as Cu 2 O and intermediate phases (CuAlO 2 and CuAl 2 O 4 ) on the mechanical property was discussed. Results show that the presence of Cu 2 O particles are detrimental to bonding strength. However, spinel CuAl 2 O 4 and isolated CuAlO 2 laminates at the interface layer can increase the bonding strength. The experimental results suggest that this thick film method is a useful technology for various metal-ceramics bonding. [ABSTRACT FROM AUTHOR]