Metallization Of Aluminum Nitride Research Articles

Hybrid laser processes for thick silver coating fabrication on AlN substrate

Aluminum nitride (AlN) are particularly suitable as integrated circuits (ICs) substrates due to its high thermal conductivity and excellent electricity insulation. However, its poor weldability with metals limits its usage. Recent research on surface metallization of AlN provides possible solutions to tackle this defect. Nevertheless, these solutions show some shortages such as complicated processes or insufficient electrical conductivity. In this paper, we report a method that consists of laser induced surface metallization and laser sintering of silver (Ag) coatings. A nanosecond laser was applied to induce a 10 μm thick aluminum (Al) layer from the AlN substrate. Afterwards, laser sintering of Ag layers was implemented, which could enhance the conductivity and the bonding performance between layers. With optimized laser parameters applied, both the electrical conductivity and the bonding tests demonstrated excellent physical properties. Finally, simulation and EDS analysis illustrated the melting evolution and confirmed a metallurgical combination of Al and Ag, thus enhancing bonding strength. Thanks to the small size of focused laser spot, electrical circuits width could be greatly narrowed if these findings were applied; hence highly dense ICs on AlN substrate become potentially available.

Effect of laser parameters and atmosphere in the structuring of aluminum nitride

AbstractThe characteristics and formation mechanism of V‐shaped groove formed by laser‐activated metallization of aluminum nitride (AlN) ceramic under different shielding gas environments of air, nitrogen, and argon are investigated, using a novel analysis way which is based on the intensity distribution of the focused laser beam. It is found that the width of the V‐shaped groove is slightly different under different gas environments, and the depth of the V‐shaped groove is nearly the same, which means that the energy thresholds required for laser decomposition of AlN ceramic are different in various gas environments: air > nitrogen > argon, and the energy required for laser etching AlN ceramic is the same. It is also found that the nonlinearity in the curves of depth and width versus different machining parameters, which are explained in detail.

Indirect-Bonded Metallization of Aluminum Nitride

AbstractThe use of aluminum nitride (AIN) as a substrate and packaging material for microcircuit applications is of present interest due to its many advantageous physical properties. A limitation to the widespread use of AIN is the lack of an adequate metallization system. The most common method of achieving high-integrity metallized ceramics is through the use of indirect-bonded metallizations. A wide range of intermediate bonding materials are used, for example glasses, oxide mixtures, and active metals. In this paper, the indirect-bonded metallization of AIN will be reviewed and discussed. Requirements which must be considered in producing successful metallizations include; wetting of the substrate and the metal by the intermediate phase and the reactivity between the intermediate phase and the substrate. The reactions which occur in many of the systems considered can be predicted by examination of thermodynamic data.