3 Replies Latest reply on Jan 3, 2013 2:12 PM by jduquette

    find via-in-pads of certain via type

    newton

      I know how to select vias of a particular type using the Find dialog. But is there way to select vias of a certain type that are overlapping with other objects, SMT pads in particular? For via-in-pad designs, I need to be able to make sure that all the vias I want filled/capped are of a particular type. I've had a couple prototype designs come back with unfilled/uncapped vias in the middle of pads because I forgot/missed to change a particular via's type. Or alternatively, is there a way to find these vias using one of the DRC methods? This would be moot if there was a way to control the type of via used in an SMT pad vs. the type of via used in general purpose routing. If a particular net will use multiple via types, then I usually have to manually set the via type for a via-in-pad via.

       

      Thanks,

      Tyrel

        • 1. Re: find via-in-pads of certain via type
          jduquette

          The best technique I've seen people use is to do that manually.  I.e. use 10 mil vias normally but use a 10.001mm via when you want it in a pad.  This only seems like a starting point though.  I haven't done via in pad before; how do you normally have the show/don't show as clearance errors?

          • 2. Re: find via-in-pads of certain via type
            newton
            I haven't done via in pad before; how do you normally have the show/don't show as clearance errors?

            I'm not sure exactly what you're asking here. However, if the via and the pad are attached to the same net, then I believe PADS doesn't throw a clearance error violation if you deselect the "Same net" check box in the Clearance Checking Setup dialog. I usually leave this unchecked anyway.

             

            Indeed, I've been manually setting the via type which is OK. But a second automated verification mechanism would be way better than manually searching the board with my eyes.

            • 3. Re: find via-in-pads of certain via type
              jduquette

              That's true.  I have put thermal vias in pads and got that to work.

               

              Maybe there is a way in the Advanced Rule Set to define difference clearance rules for different via types?

               

              Or I would think if you have an unused layer type you could show the cap/fill there in the padstack.  That may make it easier to see them, but  again it is a visual check.  You almost need to show not-capped and then make sure none of those show up in a pad.