4 Replies Latest reply on Jan 26, 2012 9:11 AM by markl

    How to add thermal relief to SMT pad?

    dmeeks

      Is there a way to add a thermal relief to a SMT pad, which is otherwise flooded over with a copper pour? Or do thermals only work on plane layers?

      Thanks

      Dan

        • 1. Re: How to add thermal relief to SMT pad?
          varora

          Go to

          Tools\OIptions\Thermals\SMT Thermals................change it to Diagonal or Orthognal (it is flood over in setting).

          • 2. Re: How to add thermal relief to SMT pad?
            dmeeks

            Thank you -

            Just to be clear: you can't select certain pads to apply this to? It looks like if you select "Rectangle" shaped pads, then ALL rectangular pads will have thermals?

             

            I don't want thermals on vias, but I do want thermals on through-hold pads for parts. Can that be done?

             

            Thanks

            dan

            • 3. Re: How to add thermal relief to SMT pad?
              varora

              You can have thermals on thru holes and flood over vias. When creating plane area, there is an option to check "flood over vias".

              Your assumtion is correct for the rectangular PADS, however there are some work around if you wish to spend time in creating them.

               

              1. Create keepout area around the rectangular pads and maually add connection to plane.

              2. Create special decal (round SMT pads with associated copper, to get rectangular pads)

              • 4. Re: How to add thermal relief to SMT pad?
                markl

                "Just to be clear: you can't select certain pads to apply this to?

                 

                "right click an SMD pin (or any pin for that matter)

                click properties

                check & uncheck plane thermal box to toggle whether it is thermal relieved or not

                 

                also check out "plane net thermal tool" & "SurfacePlaneNetThermalsTool" scripts