Air-cooling extension - performance limits for processor cooling applications

The last two decades have seen a steady increase in microprocessor performance as silicon technology continues to scale in accordance with Moore\´s law. This increasing performance of the microprocessors is also associated with an increase in thermal design power and an increase in both average power density and local power density, commonly referred to as "hot spots". The thermal solutions must ensure that the junction temperature of the processor (die temperature) does not exceed temperatures in the 90-110°C range, typically at the hot spots, to ensure device performance and reliability. The majority of OEMs (original equipment manufacturers) within the microelectronics industry would like to achieve this by extending the application of air-cooling technologies. The objectives of this paper are: 1) to present the air-cooling extension for a range of "reasonable" boundary conditions; and 2) to introduce some novel technologies, which may substantially extend the air-cooling applications.