An Integer Linear Programming Based Routing Algorithm for Flip-Chip Design

The flip-chip package provides a high chip-density solution to the demand for more I/O pads of VLSI designs. In this paper, we present the first routing algorithm in the literature for the preassignment flip-chip routing problem with a pre-defined netlist among pads and wire-width and signal-skew considerations. Our algorithm is based on integer linear programming (ILP) and guarantees to find an optimal solution for the addressed problem. It adopts a two-stage technique of global routing followed by detailed routing. In global routing, it first uses two reduction techniques to prune redundant solutions and create a global-routing path for each net. Without loss of the solution optimality, our reduction techniques can further prune the ILP variables (constraints) by 99.9% (99.9%) on average. The detailed routing applies X-based gridless routing to complete the routing. Experimental results based on five real industry designs show that our router can achieve 100% routability and the opt...

• Type: Conference
• Year: 2007
• Where: DAC
• Authors: Jia-Wei Fang, Chin-Hsiung Hsu, Yao-Wen Chang
• Keywords: DAC 2007, Design Automation, Detailed Routing Applies, Flip-chip Routing Problem, X-based Gridless Routing