6 Replies Latest reply on Dec 11, 2017 1:46 PM by johnduquette

    Can't change or use new via type


      For the board I'm currently working on, I created a new via type called "ROUTING" with the following properties:



      I created the via by following the standard procedure outlined in the help file and I selected "Use Global Defaults" only changing the drill and pad size, however I am unable to use this via as it automatically gets converted to a STANDARDVIA type when placed in Layout. I can see that it is an existing via type in the properties window:



      But immediately upon hitting "Apply", it goes back to a STANDARDVIA (shown below):




      I thought it may be an issue with changing the properties of already-routed vias, so I unrouted the traces leading to that via but with the same result. I also thought it may be an issue with changing via types in general, so I tried routing a new trace in PADS Router using the ROUTING via type, but it wouldn't let me place it. Thinking it was an issue with the drill size being below some rule I couldn't find, I made a via called "BIGVIA" which had a slightly larger drill size and pad than STANDARDVIA but was still unable to place it or change existing vias to it.


      I can't see any obvious clearance or size rules that would restrict the use of these vias, and as a cumbersome workaround I can manually change the pad stack of the vias one-by-one to be the proper size, but is there something I'm missing that renders this new via unusable?

        • 1. Re: Can't change or use new via type

          Go to Setup | Design rules | Default | Routing and move your new available via to the selected vias side.

          • 2. Re: Can't change or use new via type

            That option doesn't exist for me (see below):




            For reference, I'm on the PADS ES suite running Layout (and Router, and xDX Designer) VX.1.2


            EDIT: I tried adding the "Design Rules" button to my toolbar using the "Customize" menu, but after placing it, it's greyed out and I can't open it. I'm guessing it's because rules are handled through the "Constraint Manager" now, but I have no idea...


            Under the Constraint Manager, I see some via rules (none of which seem to preclude the use of a via with the above dimensions), but the same thing happens within the constraint manager as Layout itself - when I select "ROUTING" as the default via type and press apply, it defaults back to STANDARDVIA.


            If I look at the "Via Spans..." menu option, I can change the default via type to ROUTING, but to no effect.

            • 3. Re: Can't change or use new via type

              I created a service ticket on this and received the the following answer:


              "One of the differences between the Netlist and Integrated Projects is that you can only have one via assigned to a net in Integrated.  You can use multiple partial vias when routing, and use a different via in Router if using Component Rules, but that via will only follow the Component Rules. This difference is explained in the Netlist to Integrated Project Migration Guide for VX.1.2. – this is an important document – if you have not read it you might want to get it from the Download page on SupportNet.  It is too large to email to you.




              In VX.2 we have added Board Edge and Copper Clearance rules."


              I Spoke with the support engineer on the phone and she added that you can have multiple partial vias per net, only one through via. I changed my smaller via to a partial via type in the pad stack editor but kept the top to bottom layer pair assignment. It let me do this, but the via does not show on the via list now under either partial or through via list.


              Mentor also said that Router will allow component constraints to assign a different via under a via than in general routing for the net.

              • 4. Re: Can't change or use new via type

                We think this change is for the worse with only the option of one through hole via per net. The only way to get around this when you for instance need to use 2 different sizes on one net is to do the routing (preferable the smaller one first) then change the via under the Constraint Manager to the other one. After you done change in CM you may now shift the ones in the layout.

                • 5. Re: Can't change or use new via type

                  I was actually hoping this was something that would be changed by now, I really do not want to go back to a netlist flow

                  I have way too much time invested in Integrated Flow now.

                  But not being able to assign and easily use more than one via size on any net in the board is kind of a major

                  problem for many designs we do.

                  Is there any chance Mentor will be fixing this any time soon???

                  Can't believe his is something that got left out of Integrated Flow.

                  • 6. Re: Can't change or use new via type

                    Looks like this is supposed to be fixed in VX.2.3 next quarter: 


                    dts0101199454 - Relax rules to add any VIA in integrated flow design