>Ralllllphoooo - are you going to stimulate comments from the CAD community Here we go! We are right in sync on this one, although my reasoning comes more from the electrical side. Minimum spacing equates to max- imum coupling, in many cases. Most of today's routers apply spacing rules as "minumum" and then pack the etch in at that value until a threshold accumulation is crossed, at which time the spacing gets incremented to the next acceptable value, with another threshold, etc etc. The target is based on "how much noise can we tolerate". That's why we've travelled down another path, for years I've said "look not at the traces, but at the spaces". Our autorouting structure starts with a wide spacing and jumps to minimum only in order to get around an obstacle. Here the target is more like, "how little noise can we accumulate". In the early 90's I tried to dialogue router vendors on this point, but my cries fell on deaf ears. Good thing that hasn't stopped us. Of course, this does nothing for the 1/4 of the board with nothing on it, that's a designer's placement skills vs the engineering re- quirements vs the utilization of the board. There's still a need for thieving. Have a good weekend (if you didn't already ;) Jeff Seeger Applied CAD Knowledge Inc Chief Technical Officer Tyngsboro, MA 01879 [log in to unmask] 508 649 9800 *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************