Flip Chip Solder Bonding for Microelectronic Applications

The relentless drive towards greater complexity and interconnection density on silicon integrated circuit (SIC) devices is leading to a reappraisal of techniques for making electrical connections from the SIC to the next level of packaging. The techniques being examined include fine pitch Wire Bonding, Tape Automated Bonding (TAB) and Flip‐chip Solder Bonding. This latter technique forms the subject of this paper. The history of flip‐chip solder bonding technology is briefly reviewed and metallurgical, physical and mechanical aspects of the bonding process and of the resulting joints are discussed. The merits of the flip‐chip bonding process are indicated and applications examples presented. Particular attention is given to the fabrication of a novel pyroelectric‐SIC thermal imaging sensor using flip‐chip solder bonding.