A Multi-Pass, Multi-Algorithm Approach to PCB Routing

This paper describes a multi-pass routing technique in which each connection is initially generated in its optimum path irrespective of all other connections. Subsequent passes are utilized to resolve Pass 1 conflicts by repositioning wires. Each pass has its own algorithm which operates on a single class of connection and resolves local groups of wires at a time with respect to each other. Wires may be moved from one area of the board to another and from one side of the board to the other.