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SMD pad with opening

bdc66a938f164d

I need to create an SMD padstack that has an opening, like this:

When I draw this pad as a shape and try to save it, I get `ERROR(SPMHCS-3): Shape symbol cannot have a void in a shape.`. After a web search it seems to be a limitation of Cadence at the moment, so I tried doing two pads like this:

and then in my footprint incorporating the two pads and give them the same pad number. In this case, however, I get 

```
WARNING(SPMHA1-301): Create symbol DRC errors exist.
Duplicate pin number 1.
WARNING(SPMHA1-298): Create symbol duplicate pin numbers.

ERROR(SPMHA1-291): Create symbol has been aborted.

```

What is the way to implement this?

  • Gowtham P
    0

    Hi  ,

    An SMD pad with a hole is quite interesting! Could you help me understand the purpose or significance of having a hole or void in the pad?


    Given the current limitations, one workaround I can think of is to manually create a void on the pad after importing the .dra into the board. It might sound like a bit of a hack, but it’s one possible way to achieve the requirement.


    That said, if I understand the intent behind the void better, I might be able to look out for any other workarounds.

  • bdc66a938f164d
    0 in reply to Gowtham P

    Thank you for your suggestion. I would prefer a solution that is defined in the footprint itself, because I have to instantiate a large number of these components.

    It is a type of coaxial connector that has the ground pad completely surrounding the inner pin. It can probably work similarly well if the ground pad is split in two halves with a gap in between, but the datasheet suggests to have a hole and I would prefer to do it that way.

  • excellon1
    0 in reply to bdc66a938f164d

    Hi, Would you happen to have a link to the datasheet for this connector ?

    Best Regards.

  • excellon1
    0 in reply to bdc66a938f164d

    Hi

    I think on this, one would need the exact datasheet, is it available ?. I took a look at that connector, The manufacturer does offer footprints for it but you have to contact them. That particular connector in the link needs a step drill to drill the board as the connector is basically press fitted into the board.

    On connectors that have a center pin either SMD or TH, You could treat the part as a one pin part only and draw the body as a shape around the pin. In the pcb editor you would assign a net to the shape - Gnd. Doing this would simplify part creation as from the perspective of the PCB Editor there is only one pin even though the body exists too as a shape.

    One thing on these connectors. It would be good to ask the MFR is there a particular board material that is needed to meet spec.
    Depending on the intended frequency a standard FR4 board may not work very well above 1Ghz.

    Best Regards.

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