Far from being the passive containers for semiconductor devices of the past, the packages in today's high performance computers pose numerous challenges in interconnecting, powering, cooling and protecting devices. While semiconductor circuit performance measured in picoseconds continues to improve, computer performance is expected to be in nanoseconds for the rest of this century -a factor of 1000 difference between on-chip and off-chip performance which is attributable to losses associated with the package. Thus the package, which interconnects all the chips to form a particular function such as a central processor, is likely to set the limits on how far computers can evolve. Multichip packaging, which can relax these limits and also improve the reliability and cost at the systems level, is expected to be the basis of all advanced computers in the future. In addition, since this technology allows chips to be spaced more closely, in less space and with less weight, it has the added advantage of being useful in portable consumer electronics as well as in medical, aerospace, automotive and telecommunications products. The multichip technologies with which these applications can be addressed are many. They range from ceramics to polymer-metal thin films to printed wiring boards for interconnections; flip chip, TAB or wire bond for chip-to-substrate connections; and air or water cooling for the removal of heat.8% less power than the PWB-based product or could be allowed to run at a faster rate of transitions per second (frequency) ... Thus, thermal issues are very important in MCM design because the heat density is much higher than in single chip packages, ... An air cooled system also is more likely to survive a fan failure than a water cooled system would a pump failure. ... Air: -o- Chip Backside, Forced Air: Thermal compound PACKAGING PERFORMANCE FACTORS 109 Heat Dissipation.
|Title||:||Multichip Module Technologies and Alternatives: The Basics|
|Author||:||Daryl Ann Doane, Paul Franzon|
|Publisher||:||Springer Science & Business Media - 2013-11-27|