International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

The increasing power density in modern highperformance multi-processor system-on-chip (MPSoC) is fueling a revolution in thermal management. On the one hand, thermal phenomena are becoming a critical concern, making accurate and efficient simulation a necessity. On the other hand, a variety of physically heterogeneous solutions are coming into play: liquid, evaporative, thermoelectric cooling, and more. A new generation of simulators, with unprecedented flexibility, is thus required. In this paper, we present 3D-ICE 3.0, the first thermal simulator to allow for accurate nonlinear descriptions of complex and physically heterogeneous heat dissipation systems, while preserving the efficiency of latest compact modeling frameworks at the silicon die level. 3D-ICE 3.0 allows designers to extend the thermal simulator with new heat sink models while simplifying the time-consuming step of model validation. Support for nonlinear dynamic models is included, for instance to accurately represent variable coolant flows. Our results present validated models of a commercial water heat sink and an air heat sink plus fan that achieve an average error below 1∘C and simulate, respectively, up to 3x and 12x faster than the real physical phenomena.

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3D-ICE 3.0: efficient nonlinear MPSoC thermal simulation with pluggable heat sink models

In this article, we propose a fast thermal modeling tool, 3DSim , using a Green’s-function-based approach. Green’s-function-based approaches have been shown to be faster than the traditional finite-difference-based techniques. Our proposed tool can model steady-state and transient thermal profiles for both 2-D and 3-D chips, which may contain multiple active layers and fluid-carrying microchannels for heat removal. The unique advantage of our tool is that it models leakage power analytically using a piecewise-linear leakage model, thereby eliminating the need to iterate multiple times through the leakage–temperature feedback loop. We use several algebraic techniques and transforms to compute the thermal profile analytically and thereby speedup the process of calculation. To the best of our knowledge, transform-based approaches have not been used before to model the temperature in 3-D chips with microchannels. Our approach provides a $150\times $ speedup over state-of-the-art thermal simulators, with an error limited to 5%.

A Fast Leakage-Aware Green’s-Function-Based Thermal Simulator for 3-D Chips

Emerging monolithic 3D integration: Opportunities and challenges from the computer system perspective

Voltage Scaling for 3-D ICs: When, How, and How Much?

Fast and accurate thermal analysis is crucial for determining the propagation of heat and tracking the formation of hotspots in integrated circuits (ICs). Existing academic thermal analysis tools primarily use compact models to accelerate thermal simulations but are limited to linear problems on relatively simple circuit geometries. The Manchester Thermal Analyzer (MTA) is a comprehensive tool that allows for fast and highly accurate linear and nonlinear thermal simulations of complex physical structures including the IC, the package, and the heatsink. The MTA is targeted for 2.5/3-D IC designs but also handles standard planar ICs. The MTA discretizes the heat equation in space using the finite element method and performs the time integration with unconditionally stable implicit time stepping methods. To improve the computational efficiency without sacrificing accuracy, the MTA features adaptive spatiotemporal refinement. The large-scale linear systems that arise during the simulation are solved with fast preconditioned Krylov subspace methods. The MTA supports thermal analysis of realistic integrated systems and surpasses the computational capabilities and performance of existing academic thermal simulators. For example, the simulation of a processor in a package attached to a heat sink, modeled by a computational grid consisting of over 3 million nodes, takes less than 3 min. The MTA is fully parallel and publicly available. 1

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The MTA: An Advanced and Versatile Thermal Simulator for Integrated Systems

In the era of post-device scaling, three-dimensional (3-D) integration is a promising solution to meet performance, power, and cost requirements in modern applications, such as IoT, high performance computing, and cyber-physical systems. A novel design automation flow, compatible with static timing analysis (STA), for exploring the timing and power of 3-D ICs is proposed. Among the different types of vertical interconnects, TSVs modeled as RC wires, are considered in this work. The flow enables design space exploration and optimization utilizing existing timing and power analysis tools, e.g. PrimeTime and PrimeTimePX. The design experience is similar to a 2-D design flow where the placement in multiple tiers is merely performed by an open-source 3-D placer. Application of the flow to different benchmark circuits shows that even with no optimization effort, a two tier 3-D stack produced by the flow achieves up to 14.6% average power reduction, 18.7% performance improvement, and 49% footprint reduction as compared to the 2-D design for a specific circuit.

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Yi-Chung Chen

Papers

The MTA: An Advanced and Versatile Thermal Simulator for Integrated Systems

STA compatible backend design flow for TSV-based 3-D ICs