(Georgia Institute of Technology, 2008-09-09)
Kohl, Paul A.; Spencer, Todd; Osborn, Tyler
The "off-chip" bandwidth is a major bottleneck causing system delays and limited throughput, especially in areas such as processor-to-memory bandwidth and processor-to-network. The ITRS cites off-chip signal bandwidth exceeding 60 GHz within 10 years. Organic substrates (i.e. chip packages or interposers) with flip-chip solder connections are the core of the first and second level of interconnect. Off-chip bandwidth is limited to several GHz due to frequency dependent attenuation, signal reflections, and crosstalk within the polymer dielectric, via structures, and I/O signal path transitions within the chip substrate and mother board.
In this work, we have introduced advances in off-chip interconnect using air-isolated, coaxial links on substrates and boards to demonstrate ultra high-speed chip-to-chip and chip-to-network communications. New approaches have been found to fabricating high frequency I/O, air-and isolated coaxial links on the substrate. The materials, processes and electrical characteristics will be presented.