4 Replies Latest reply on Feb 9, 2011 5:19 AM by erdin_sinanovic

    Best way to route traces in 45 degree?


      Hi guys!


      I've been trying to route a length restricted diff pair in a 45 degree traces over the PCB and then round the corners with "Modify Corners". The problem is, that Expedition does not generate 90 degree corners consistently. 50% of the time the 90 degree corners have a not visible 45 degree inside. This makes the "Modify Corners" tool fail at these corners. I already switched off Gloss, but the problem remains. To uncheck the option "Allow 45 degree corners" in the Editor Control under the Route tab is also not applicable, because then I can only route in horizonal or vertical lines but not in 45 degrees over the PCB. So is there a way to create 90 degree corners without much hassle?


      Thanks in advance!

        • 1. Re: Best way to route traces in 45 degree?



          Here is what I do...


          Route your diff pairs with 45 deg angles turned on, do not try and get 90 deg angles. Once you have completed the routing of the pair, select an outer segment at the 45 deg portiion of the routed trace, RMB Click and use the ARC Stretch command. It is a post process that dioes not get all corners at once, but you will get a much cleaner arc and the diff pair will be maintained. It is also very easy to edit at a later time if required.


          I hope this will help.



          • 2. Re: Best way to route traces in 45 degree?



            Thanks for your reply! I just wanted to try your advice, but it seems that my version of Expedtion does not have an ARC Stretch command. Neither in the RMB dialog nor somwhere else. BTW I'm using version 7.9.1. Maybe this is the reason.

            • 3. Re: Best way to route traces in 45 degree?

              Arc stretch only be available when a Flex license option acquired.


              • 4. Re: Best way to route traces in 45 degree?

                Thanks for the tip!


                Eventually I've found the tool, but in fact it's no use for me. But I found another way, how to overcome the problem.

                First I've routed only one trace of the diff pair with Gloss disabled in a big grid in order to make the corners and the trace itself the same size. After that I routed the other trace of the pair without a grid. This doesn't need to be drawn exact. After finishing this one I moved this trace as near as defined to the other trace to keep the distance everywhere as specified in CES.

                Now that it is fully routed, I can use the "Modify Corners" tool and generate rounded corners, which are exact the same.

                After that I check the final length. If it doesn't match, I undo the rounded corners and modify the traces. This adds no additional corners, so I can use the "Modify corners" tool again.

                This procedure can be repeated as long as the length doesn't match.