11 Replies Latest reply on Apr 25, 2014 8:08 AM by dcox

    change trace 90 degree to 45 degree


      Hi, now I'm new to PCB design. I just finished placing components on PADS layout and now learning routing.

      How can I change trace degree from 90 to 45 degree?

      Also, when I change trace width from 12 to 6, the wide line becomes a thin line like same as rat's nest. (when the line width is 12, the trace line is wide, but the trace with is either <12, it becomes very thin line.)

      Is there any setting for that?

      I hope someone can answer my question, thanks.

        • 1. Re: change trace 90 degree to 45 degree


          Use modeless command AD (for 45 deg), AO (for 90 deg) and AA for any angle.

          For traces - press Ctrl+Enter and go to General-->Minimum displat width. Set this value to 5 mils and everythink will be OK.


          • 2. Re: change trace 90 degree to 45 degree


            for the first question you want to change the existing 90 traces to 45 degrees? or while routing you want to change the angle?


            if you want to change the angle while routing you can change in tools>option>design>line/trace angle


            and for the second question just type R0 so that you can see the traces with real width

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            • 3. Re: change trace 90 degree to 45 degree

              After you route a 90 degree corner you can convert it to a 45 degree corner with a miter.  Select the corner (both the vertical and horizontal traces will be highlighted) and then <right-click> and select 'Add miter'.


              After you add the miter you can select just the miter and then press <Shift-S> to resize the miter.

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              • 4. Re: change trace 90 degree to 45 degree

                Thank you very much.

                • 5. Re: change trace 90 degree to 45 degree

                  thank youvery much.

                  • 6. Re: change trace 90 degree to 45 degree

                    Thank you very much.

                    • 7. Re: change trace 90 degree to 45 degree

                      I have one more question. When I want to change the trace like below, (the traces become narrower from some point)

                      which way is the best way? Thanks in advance...


                      • 8. Re: change trace 90 degree to 45 degree

                        Which way is the best way for what?  I don't understand your question.


                        When I have to change a trace width I'll sometimes do a taper (100 mils long at 10 mils, 100 mils long at 9 mils, 100 mils long at 8 mils...) but I only do this when I'm concerned about reflections at very high frequencies; even then it isn't the best practice.  Why are you changing the trace width?

                        • 9. Re: change trace 90 degree to 45 degree

                          I think liont is asking how to change the trace width on the same signal (like breaking it into 2 segments, part is 12 mil (ie.), the other part is 4 mil. ).  I guess you will have to change the width when the signal is connecting to a chip / connector pad.

                          • 10. Re: change trace 90 degree to 45 degree
                            Hande Erdogan

                            While routing, you can use "w" modeless command to change trace width. i.e. "w  7". If it can not change, it seems you wrote bigger number than min.&max trace width, you set in clearance design rules.

                            • 11. Re: change trace 90 degree to 45 degree

                              I believe the question has to do with how the actual corner location moves when an angled route is mitered into a round one.  The amount of trace length used up is a function of the trace width, the angle and the miter ratio value.  Lets say you have a trace corner that is 100 mils away from a 50 mil dia pad.  Without mitering, you have 75 mils of straight trace between the pad edge and the corner.  If you convert that corner to a round mitered corner with a value of 1, your straight section is reduced by 1/2 the miter value multiplied by the trace width before it enters the curve.  The wider the trace, the more of the straight segment is used up.  For example, a 100 mil wide trace runs 300 mils to a 90 deg corner and then runs off for a long distance.  If you miter the corner with a ratio value of 1, the trace now only runs 250 mils out before it starts the curve of the corner.  (100 mil trace, 100 mil dia corner) A miter ratio value of 2 shortens it to 200 mils, because the curve corner now has a diameter of 200 mils.  You can increase the ratio up to a value of 6, at which point there is no more straight trace exiting the pad, but the curve starts right at the pad.  A value of 7 has no effect on the corner.  If a straight segment coming out of a corner is not long enough to support the miter, it will not display.  If you have a small zig zag in a long trace, the short section must be long enough to support two length reductions, one for each end. In your case, your angle was 135 deg, so your miter value shortened the trace segment coming up out of the pad to the point where the curve started before the trace exited the pad.  This will remove teardrops, if you had them.  Teardrops require a minimum segment of straight track coming out of a pad to support the teardrop configuration.  If the trace is too short, the teardrop will not display.  The way to fix this is to a: lower your mitre ratio value and reassign the corner and change the teardrop configuration for that segment.


                              Also, you can rmb to bring up the Selection filter and check only Corners.  Then block select the entire board.  You could concievably then miter all the corners at once, but not all corners may miter if one leg is too short.