Patent ID: 8327306

Claim:
A method for optimizing locations and a number of power/ground pads on a power/ground distribution network with multiple voltage domains in a layout of an integrated circuit using bump bonding, the method comprising: a first optimized pad selecting step, which is performed by a computer, of analyzing, the power/ground distribution network for each pad using a global optimization method to find nodes having a worst IR drop for each pad respectively, and selecting a pad corresponding to a node having a minimum worst IR drop among nodes having the worst IR drop as a first optimized pad; a second optimized pad selecting step, which is performed by the computer, of finding a second optimized pad nearest to the node having the worst IR drop found from an analysis of the power/ground distribution network with the first optimized pad; a local optimization step, which is performed by the computer, of analyzing the power/ground distribution network by simultaneously applying optimized pads selected so far to the power/ground distribution network to find a node having the worst IR drop, finding a pad nearest to the node having the worst IR drop and selecting the pad as an optimized pad; an optimization constraints determination step, which is performed by the computer, of ending the local optimization step if a maximum IR drop value of the first optimized pad selected in the first optimized pad selecting step, the second optimized pad selected in the second optimized pad selecting step or the optimized pad selected in the local optimization step is smaller than a predetermined reference value or a maximum current value of the first optimized pad selected in the first optimized pad selecting step, the second optimized pad selected in the second optimized pad selecting step or the optimized pad selected in the local optimization step is smaller than another predetermined reference value and an optimization completing step, which is performed by the computer, of repeating the local optimization step until optimization constraints are satisfied in the optimization constraints determination step, storing information about selected optimized pads when the optimization constraints are satisfied and ending the local optimization step.