Comparison of Wafer Scale Integration with VLSI Packaging Approaches

A comparison is made of various high-density packaging approaches, including printed wiring board, thick-film hybrids, and wafer scale integration (WSI). Criteria include power dissipation, density, delays, and cost. It is concluded that thin-film hybrids using state-of-the-art VLSI chips have the potential for WSI density and performance. The requirement for fault tolerance, additional levels of metallization, excess power dissipation, process conservatism to achieve finite yield, and the nonoptimum nature of the Al/Si02transmission line for cross wafer communication have made WSI noncompetitive.