Transient thermal analysis of global interconnects based on transmission lines

In this paper, an efficient numerical method is proposed for transient thermal analysis of global interconnects. The thermal behaviour of global interconnects is modelled as two dimensional heat transfer. The horizontal heat conduction along the line is described by the differential form of one dimensional heat diffusion equation, and the vertical heat conduction from the line to the substrate is modelled by the corresponding thermal transmission lines with the input admittance reduced by one moment matching technique. Then finite difference method is adopted to solve the proposed heat diffusion equation and the transient thermal response of global interconnects can be obtained. Numerical results show that the proposed method is more efficient than thermal field solver based on finite element method, and more accurate than equivalent thermal circuit solutions, with accuracy above 98%.