Due to increasing complexity of design interactions between the chip, package and PCB, it is essential to consider them at the same time. Specifically the finger/pad locations affect the performance of the chip and the package significantly. In this paper, we have developed techniques in chip-package codesign to decide the locations of fingers/pads for package routability and signal integrity concerns in chip core design. Our finger/pad assignment is a two-step method: first we optimize the wire congestion problem in package routing, and then we try to minimize the IR-drop violation with finger/pad solution refinement. The experimental results are encouraging. Compared with the randomly optimized methods, our approaches reduce in average 42% and 68% of the maximum density in package and 10.61% of IR-drop for test circuits.