TWIGY A Topological Algorithm Based Routing System

A two-level approach to routing is described, in which a multi-layer printed circuit board routing problem is broken down into a set of single-layer ones. A topological transformation is then applied to accomplish single-layer routing. A solution found for each layer by a search in this new domain is then translated back into physical space by means of a deterministic drawing algorithm. The algorithms are independent of specific technological parameters, affording their use on a variety of board routing grids, pad diameters and wire sizes.