Automatic printed circuit board routeing with intermediate control of the tracking: APRICOT

Abstract

For several years computers have been used to produce artwork for printed circuit board manufacturer in basically two different modes. In the automatic mode the computer decides most, if not all, of the track routes and relies on the human to add the unrouted connections. This can be done in an essentially offline manner but it is error-prone. In the interactive mode, which may follow the application of an automatic program, the unrouted connections are manipulated on a graphical display. This is essentially an error-free process but it is performed online. This paper describes a new approach to automatic routeing that allow ‘error-free’ manipulation of the routeing in an offline manner. The automatic routine uses a planned, as opposed to a search, technique and this allows intermediate control (offline) of the automatic routeing process. It also enables the user to change component positions at any time during the routeing process in an offline mode.