Routing of Printed Circuit Boards

A software program for the routing of printed circuit boards is discussed in this paper. This program is part of a system which includes reading data from the engineer's schematic diagram, placing the components on the board, and routing the connections. The layout is then worked upon on a graphic display to improve and complete the routing, which is then used to produce the pc board. In this paper only the router is discussed. The results are that with boards with 6 signal layers and about 3 chips per sq. in. over 99% of the paths were found. This work demonstrates that a maze-runner can be an excellent router, if one guides the maze-runner properly by encouraging the paths to have the desired properties, and by introducing restrictions so that the paths tend to lie on regular directions with a minimum of interference with each other.