2018/04/25 by Varun A. Baheti, Baheti, Varun A
Engineering · Materials Science · #Electronic Packaging and Soldering Technologies #3D IC and TSV technologies #Copper Interconnects and Reliability
paper · pdf · doi:10.48550/arxiv.1804.09595
The electro–mechanical connection between under bump metallization (UBM) and solder in flip–chip bonding is achieved by the formation of brittle intermetallic compounds (IMCs) during the soldering process. These IMCs continue to grow in the solid–state during storage at room temperature and service at an elevated temperature leading to degradation of the contacts. In this thesis, the diffusion–controlled growth mechanism of the phases and the formation of the Kirkendall voids at the interface of UBM (Cu, Ni, Au, Pd, Pt) and Sn (bulk/electroplated) are studied extensively.