A Self-Consistent Substrate Thermal Profile Estimation Technique for Nanoscale ICs—Part I: Electrothermal Couplings and Full-Chip Package Thermal Model

Abstract

As CMOS technology scales to nanometer regime, power dissipation issues and associated thermal problems have emerged as critical design concerns in most high-performance integrated circuits (ICs) including microprocessors. In this scenario, accurate estimation of the silicon junction (substrate or die) temperature is crucial for various performance analyses and chip-level thermal management. This paper introduces the notion of self-consistency in the junction temperature estimation by taking into account various electrothermal couplings between chip power, average junction temperature, operating frequency, and supply voltage. The self-consistent solutions of the average junction temperature are shown to have significant implications for various chip-level power, performance, reliability, and cooling cost tradeoffs. Moreover, a realistic package thermal model is introduced that comprehends different packaging layers and noncubic structure of the package, which are not accounted for in traditional analyses. The model is subsequently incorporated in the self-consistent substrate thermal profile estimation, which is discussed in Part II with implications for power estimation and thermal management in nanometer-scale CMOS technologies.