Towards a Thermal Moore's Law

Abstract

Thermal design power trends and power densities for present and future single-core microprocessors are investigated. These trends are derived based on Moore's law and scaling theory. Both active and stand-by power are discussed and accounted for in the calculations. A brief discussion of various leakage power components and their impact on the power density trends is provided. Two different lower limits of heat dissipation for irreversible logic computers that have previously appeared in the literature are discussed. These are based on the irreversibility of logic to represent one bit of information, and on the distribution of electrons to represent a bit. These limits are found to be two or more orders of magnitude lower than present-day microprocessor thermal design power trends. Further, these thermal demand trends are compared to the projected trends for the desktop product sector from the International Technology Roadmap for Semiconductors (ITRS). To evaluate the thermal impact of projected power densities, heat sink thermal resistances are calculated for a given technology target. Based on the heat sink thermal resistance trends, the evolution of a consistent air-cooling limit is predicted. One viable alternative to air-cooling, i.e., the use of high-efficiency solid-state thermoelectric coolers (TECs), is explored in detail. The impact of different parasitics on the thermoelectric figure of merit (ZT) is quantified.

Surface Structure Enhanced Microchannel Flow Boiling

“…The increasing power densities in various electronic devices including concentrated photovoltaics, power electronics and laser diodes pose significant thermal management challenges for the electronics industry [1][2][3]. Two-phase microchannel heat sinks are attractive to cool advanced electronic devices because they harness the latent heat of vaporization to dissipate high heat fluxes in a compact form factor.…”

Determination of Electrical Contact Resistivity in Thermoelectric Modules (TEMs) From Module-Level Measurements

“…The predicted maximum cooling achieved by the thin-film TEMs, with and without the interfacial resistances included, were 14.9°C and 25°C, respectively [9] for a heat load of 1,300 Wcm −2 . Krishnan et al [11] showed thin-film TEMs to be a viable technology to cool high heat fluxes in electronic equipment. The interfacial Ohmic heating was shown to drastically affect the performance of these TEMs, especially at micron sizes.…”

Enhanced thermal transport at covalently functionalized carbon nanotube array interfaces

“…T hermal transport limits the performance of many technologies such as micro and nano electronics and optoelectronics, micro-electro-mechanical systems, and important energy technologies including thermoelectric generation, concentrated photovoltaic systems and electrochemical batteries [1][2][3][4][5] . Although significant advances such as microchannels, heat pipes and thermoelectrics 6,7 have been made in thermal devices for various applications in the last few decades, performance is often limited by the interface between these devices and the components whose temperature needs to be controlled 7 .…”