Mm-wave flip-chip fabrication process for MnM-based interposer interconnection

This paper presents experimental results of a Flip Chip (FC) fabrication process. The FC technology is based on next generation fine pitch Cu Pillar bumping, which pitches less than 100 μm that support next generation communication devices at the mm-wave frequency range. The purpose of this article is to shed some light on the technical background and to highlight the key issues. This will be done from the point of view of the manufacturing process. It was shown that highly miniaturized Cu Pillar pitches and significantly Cu Pillar thickness can be obtained. Furthermore, this work aims to get advances in Cu Pillar fine pitch FC fabrication process that will be useful as integration technology within nanoporous alumina substrate - based interposer for the development of mm-wave devices. Accordingly, the article will discuss flip-chip fabrication process challenges in both Fine Cu Pillar fabrication and substrate-chip bonding.