1 2 First Previous 18 Replies Latest reply on May 17, 2018 1:45 PM by jjames

    CLEARANCE RULE ?

    jjames

      I am very new to pads. When I created the schematic, i didnot put the clearance between the VIN(+) and VIN(-). I would like to set up a 40MILS clearance between VIN(+) and VIN(-). How do i do that. I click set up -> design rules but there are option for default, classes, nets, conditional rules, differential rules. which one should I use and how ?

      Also how can I set a specific rule for a specific via.

       

      Please help me

       

      Thank You

        • 1. Re: CLEARANCE RULE ?
          md.direct

          The order of priority if from left to right of that Design Rules Dialog box. Default being the least priority, Class the next one and so on up to Component being the highest.

           

          Snagit1-34.png

           

          In other words, Assigning a rule to a Net takes priority over a rule in a Class where that net is a member.

          Having said that, I would use the Nets Rules to assign a specific rule between two nets.

          However, there is no way to set a specific rule for a specific via. With more details about what you are trying to achieve, I could probably help.

          Which version of PADS standard are you using ?

          • 2. Re: CLEARANCE RULE ?
            jjames

            via.PNG

            Pins.PNG

             

             

            Clearance.PNG

            Thank You very much for your help. I am using Pads 9.4.

            I have attached two images.

            1) the first image "Via" is a via. I just want that two via to flood over with no thermal spoke. what should I do ?

            2)the second image "pin", I also want to flood over this two pins without thermal spoke but would like to keep all other pins with thermal spoke. what should i do ?

            3) the third image is the clearance you suggested. I clicked nets. I clicked 48_INPUT(+) and i clicked clearance. But lets say I want 40Mil clearance between 48_INPUT(+)  and AGND. how do i do that ?

             

            Thank You

            • 3. Re: CLEARANCE RULE ?
              md.direct

              Ok, PADS 9.4 ... pretty old to me ;-)

              I'm using VX.2.3

               

              1.) Via flooding is specified at the Plane Shape level:

              2018-05-14_13-02-59.jpg

              2.) Pin flooding is usually done at the Decal Level, within the Padstack:

              2018-05-14_13-05-40.jpg

                 

                 But can also be done at the Component Level in Layout (not prefered as an Update Part would revert to Library):

              2018-05-14_13-09-48.jpg

               

              3.) Once you have assigned a rule to a net, that same net can not be assign a different rule in the same category (in this case Nets). Instead, I would define the rule between the first two nets as before, but I would also create a Class containing these two nets and a Class containing AGND then assign a rule between the two Classes. Conditionnal Rules could be something else to use ...

              • 4. Re: CLEARANCE RULE ?
                md.direct

                Since all of the three nets have to be away by 40mils, why not simply put them into the same Class and set the clearance to 40mils in there ?

                Of course, you probably don't only have these 3 nets to deal with ... so the rest of the Rules have to be set accordingly ;-)

                • 5. Re: CLEARANCE RULE ?
                  md.direct

                  I am using PADS Professionnal VX.2.3 ... and soon will drop PADS Standard as it is not as powerful and efficient as PADS Professionnal.

                  • 6. Re: CLEARANCE RULE ?
                    jjames

                    Thank You so much for your help. Really appreciated. I was trying to do the flooding the PIN but it seems Pads 9.4 does not have that option. I cant find that

                     

                    I appreciate your help

                    • 7. Re: CLEARANCE RULE ?
                      jjames

                      I am trying to make a trace at the top and also at the bottom. But after i connect to the top and go to the bottom to make another trace. The top one goes of. Why is it ?. Is there any command to make double traces ? Please help.

                       

                      Also I see alot of rats nest in the layout but when i run verify design it doesnot show any error. Why is that ?

                      • 8. Re: CLEARANCE RULE ?
                        md.direct

                        I am assuming you are routing using PADS Router ?

                        • 9. Re: CLEARANCE RULE ?
                          jjames

                          I am using Pads layout. Thank you

                          • 10. Re: CLEARANCE RULE ?
                            md.direct

                            1.) I only know of a way to allow for "Loop" in PADS Router. To be honest with you, I NEVER use PADS Layout to route.

                             

                            2.) In regard with the rastnet issue. In PADS Layout (VX.2.3), under menu "View/Nets..." try with the setting as below.

                             

                            Snagit1-38.png

                            • 11. Re: CLEARANCE RULE ?
                              jjames

                              Thank you for your help. I tried to do the rastnet under the menu and it seems all my options are greyed out.

                               

                              nets1.PNGnet2.PNG

                              • 12. Re: CLEARANCE RULE ?
                                md.direct

                                You need to selected the Nets under the View List ...

                                • 13. Re: CLEARANCE RULE ?
                                  jjames

                                  Thank You for your help. I did that but still it has rast nest.

                                  Can I ask how do you connect a trace to a plane without a via. I want to run a trace from a pin and want to connect to a plane but for some reason i can only connect to the plane through a via.

                                   

                                  Thank You

                                  • 14. Re: CLEARANCE RULE ?
                                    md.direct

                                    Hi,

                                    It really sounds like you need a training on PADS Layout.

                                    Trying to help you here is kind of very difficult as I would need to show you what to do rather then telling you what to do through messages back and forth.

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