Abstract
Aluminum nitride (AlN) is expected to be suitable as substrates and packages for microelectronic devices because of its high thermal conductivity, excellent electrical properties, and thermal expansion coefficient close to that of silicon. These properties make AlN an excellent candidate to replace alumina (Al2O3) and beryllia (BeO) used for the manufacture of semiconductor devices. This paper shows the state-of-the-art in AlN ceramics, aiming to show the advances in processing developed in the last decades for the applications in electronic devices. Another objective was to verify the possibility of using AlN in structural applications. AlN ceramics exhibited significant technological advances over the past decades, as diminution in synthesis and sintering temperatures, synthesis of water resistant powder, and production of ceramic substrate by the direct bonding copper technology. However, most of these technological advances were not introduced in the industrial routes for large-scale production. As a result, the production costs were not reduced sufficiently to make AlN attractive for the microelectronic industries. Although AlN and Al2O3 have relatively close mechanical properties, AlN is unattractive as a structural material because of its high production cost in comparison to Al2O3. Therefore, previous and current developments in processing must be implemented industrially to promote cost reduction, increasing the competitiveness of AlN in the electronic and structural ceramics markets. These markets can also be expanded using AlN in new applications such as armor products and nanostructured devices (optoelectronic components, high-energy lasers, pulse wave sensors, mechanical resonators, light-emitting diodes, and field electron emitters).
Keywords:
AlN; synthesis; sintering; thermal conductivity; mechanical properties
