This work develops an efficient chiplet placer with thermal consideration for 2.5D ICs. Combining the sequence-pair based tree, branch-and-bound method, and advanced placement/pruning techniques, the developed placer can find the solution fast with the optimized total wirelength (TWL) on half-perimeter wirelength (HPWL). Additionally, with the post placement procedure, the placer reduces maximum temperatures with slight increase of wirelength. Experimental results show that the placer can not only find better optimized TWL (reducing 1.035% HPWL) but also speed up at most two orders of magnitude than the prior art. With thermal consideration, the placer can reduce the maximum temperature up to 8.214 °C with an average 5.376% increase of TWL.

This work presents a system-level thermal simulator, Phone-nomenon, to predict the thermal behavior of smartphone. First, we study the nonlinearity of internal and external heat transfer mechanisms and propose a compact thermal model. After that, we develop an iterative framework to handle the nonlinearity. Compared with a commercial tool, ANSYS Icepak, Phonenomenon can achieve two and three orders of magnitude speedup with 3.58% maximum error and 1.72°C difference for steady-state and transient-state simulations, respectively. Meanwhile, Phone-nomenon also fits the measured data of a built thermal test vehicle pretty well.

To sustain Moore's law, three-dimensional integrated circuit (3-D IC) is a promising solution to achieve high performance and low cost targets. However, its operating temperature is higher than that of a 2-D IC because of its high power density of stacked dies and ill of heat dissipation capability. Therefore, on-chip thermal effects have become major concerns of 3-D ICs. Utilizing look-up table approach, this paper, LUTSim, provides two thermal simulation engines, I-LUTSim and S-LUTSim, to efficiently calculate the thermal profile of a 3-D IC. I-LUTSim is suitable for full-chip thermal analysis, and S-LUTSim is suited for incremental-thermal updating. With utilizing the prebuilt tables, compared with a commercial tool ANSYS, the absolute error of I-LUTSim is less than 0.29%. Moreover, with negligible loss of accuracy, I-LUTSim can be 38.8 times faster than a well-known matrix solver SuperLU for performing full-chip thermal simulation. Besides, S-LUTSim can be over 1.05 million times faster than SuperLU for adjusting the thermal profile after inserting/removing a through silicon via.

This work presents an iterative look-up table based thermal simulator, I-LUTSim, to efficiently estimate the temperature profile of three-dimensional integrated circuits. I-LUTSim includes two stages. First, the pre-process stage constructs thermal impulse response tables. Then, the simulation stage iteratively calculates the temperature profile via the table lookup. With this two-stage scheme, the maximum absolute error of I-LUTSim is less than 0.41% compared with that of a commercial tool ANSYS. Moreover, I-LUTSim is at least an order of magnitude faster than a fast matrix solver SuperLU [1] for the full-chip temperature simulation.

This work introduces the concept of thermal yield profile for the hot-spot identification with considering process variations and provides an efficient estimating technique for the thermal yield profile. After executing a mixed-mesh strategy for generating statistical polynomial expression of the on-chip temperature distribution, the thermal yield profile is obtained by a skew-normal based moment matching technique. Comparing with the Monte Carlo method, experimental results demonstrate that our method can efficiently and accurately estimate the thermal yield profile. With the same level of accuracy, our skew-normal based method achieves 215x speedup over the state of the art, APEX [1], for estimating the thermal yield profile. Moreover, results show that our mixed-mesh statistical polynomial expression generator achieves 130x speedup over the statistical collocation based method [2] and still accurately estimates the thermal yield profile.