Fine line multilayer substrates with very high density TAB

The authors describe ESPRIT Project 958, which is concerned with the development of two major interconnect technologies: high-density TAB (tape automated bonding) and a compatible high-density multilayer substrate technology. The main developments in TAB have been aimed at enabling the bonding of VLSI chips on high-density substrates and include improvements in bump formation, tape realization, and the bonding (attachment) operations. For the substrates, the main activities have been in developing the technology for fabricating very fine tracks, gaps, and via holes, to match the TAB VLSI devices. These, together with electrical and thermal design, modeling, and testing techniques, have led to the building of multichip, high-density demonstrators, dissipating high power and exhibiting high speed (Gb/s) operation