Nanoporous gold for MEMS packing applications

On-chip nanoporous gold (NPG) fabrication has been successfully developed by Au-Sn alloys electrodeposition and dealloying process, to use its compressible body and nanostructured surface for micro electro mechanical systems (MEMS) applications. Anodically-bondable low temperature cofired ceramic (LTCC) substrates are proposed to provide electrical connective packaging by using novel nano-structured gold. The porous structure offers sponge-like functions which forms electrical contacts as well during anodic bonding. Nanoporous gold with porosity in nanoscale indicates a highly reactive surface which makes it possible to be a promising candidate for bonding process to reduce the bonding temperature. Low temperature bonding has been achieved by using nanoporous gold. These encouraging results imply good possibilities of nanoporous gold for MEMS packaging applications.