Introduction The need for new cooling techniques is driven by the continuing increases in power dissipation of electronic parts and systems. In many instances standard techniques cannot achieve the required cooling performance due to physical limitations in heat transfer capabilities. These limitations are principally related to the limited thermal conductivity of air for … [Read more...]
High Powered Chip Cooling — Air and Beyond
Introduction Over the past few years many people in the electronics industry have become concerned with the increases in heat density at both the chip and module level of packaging. This trend is not new and has been with us since the days of bipolar chips. As can be seen in Figure 1, the heat flux associated with bipolar circuit technologies steadily increased from the … [Read more...]
Latest Developments In Thermoelectrically Enhanced Heat Sinks
Nomenclature Q Heat load (W) COP Coefficient of Performance I Electrical current (Amps) T Temperature (°C) R Electrical resistance (Ohms) Z TE Figure of Merit (1/K) where Z = α2 / (ρ λ) Greek Letters Δ Change in value θ Thermal resistance (°C/W) ρ Electrical resistivity (Ohm-cm) α Seebeck coefficient (V/K) λ Thermal conductivity … [Read more...]
Liquid Cooling is Back
Introduction IBM announced its return to water cooling on April 19, 2005 with the introduction of a water cooled heat exchanger mounted to the back cover of a 19 inch rack. This is the first of the major datacom equipment manufacturers to employ water cooling for a rack of CMOS processors, using a cooling distribution unit supplying the water and rejecting the heat load to … [Read more...]
Review of Low Profile Cold Plate Technology for High Density Servers
Introduction Water cooling of computers was introduced more than twenty years ago, but had disappeared from the mainstream by the mid 1990s. The conversion of chip technology from bipolar to CMOS (complementary metal oxide semiconductor) was the main reason. As chip powers continue to increase, water cooling appears likely to become mainstream again. In the current market, the … [Read more...]
