6. Thermal performance

Integrated circuits are imperfect components, so their operation generates a flow of heat. Thermal problems therefore remain a central concern for packaging specialists. The heat flux dissipated by an integrated circuit can exceed 10 ⁶ W.m ^-2 . Such a flux is far greater than that of an iron (around 500 W.m ^-2 ). The performance of an integrated circuit decreases markedly with its operating temperature; a CMOS circuit sees its switching time affected by around 3% if its temperature rises by 10°C. Operating temperature also has an influence on component reliability: to a first approximation, the failure rate doubles for every 10°C increase in temperature. The task of thermal engineers is therefore to take these constraints into account, in order to maintain...