Packaging assessment of porous ultra low-k materials

The need for lower effective dielectric constants for both inter- and intra-layer dielectrics is clearly stated in the International Technology Roadmap for Semiconductors. Recently some progress has been reported with regards to integration and reliability assessment of these new, relatively weak porous ultra low-k materials. Due to their mechanical weakness, these materials also present unique challenges to the packaging process. If no appropriate precautions are taken, the parts cannot be packaged at all. In this paper first results are presented for packaging of a porous ultra low-k material with different integration schemes, employing three assembly techniques: flip chip, gold ball bonding, and aluminum wedge bonding. All of these assembly techniques achieved good assembly yields when proper integration schemes were used.