Thermal and Wirelength Optimization with TSV Assignment for 3-D-IC

3-D-IC is an emerging technology that overcomes the drawbacks of 2-D-IC and a vital structure called through-silicon via (TSV) is used to connect the adjacent layers vertically. In this paper, based on graph theories, we formulate the TSV assignment as an integer multicommodity min-cost (IMCMC) problem, and using multilevel algorithm, we get optimal solution. During the assignment, the capacity of the grid could be insufficient to contain the flows so that conditional grid extension effectively relieves the capacity limits and accelerate running speed. Thermal resistive model is introduced to simulate the heat dissipation of chip and estimate temperature distribution each layer. By inserting the thermal TSV, the temperature of superheated region is reduced. Moreover, considering about a more complicated situation, we propose a method to assign multipins in a net. The experimental results demonstrate our model in the IMCMC network using multilevel algorithm achieve optimized congestion, less wirelength, higher running speed, and reduced temperature.