A routing technique using fuzzy sets theory

In PCB designs, a clearance that means the allowable minimum spacing between conductors is defined. The clearance, which is given numerically by designers, specifies the boundaries of an area whereby other conductors are kept out of the area. When an automated router performs wiring based on simple numeric clearances, traces are often placed along the boundaries of a clearance. This makes routing subsequent nets virtually unfeasible, leading to the problem that a rip-up and reroute process has to be repeated over and over again. This paper presents a routing technique using the clearance that is represented by fuzzy sets, in order to introduce human perception to PCB routing. We incorporated the concept of clearances based on fuzzy sets theory into a maze-running algorithm and tested the effectiveness