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correct RF shield footprint, with parts inside

PascalVM

Hi, I have a footprint for a RF shield. I'm getting a lot of DRC errors "package to package spacing", basically for any part that is placed within the RF shield.

Here are screenshots. What would be the appropriate way to handle this footprint, so that it would not produce these errors?

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  • RFinley
    in reply to CadAce2K

    C13 and L8 look like a drain bias network.  Those usually don't change as much.

  • RFinley

    I'm sorry but I have to bring this up.

    The copper pour around the RF lines needs to have clearance that is as wide as your trace width (3W rule) to avoid having a lower impedance than you are expecting (eats the signal.).

    Kudos for fitting this into an off-the-shelf shield can. But, L2,  C2.  Do they have to be inside this shield?  C2 should have routing like C5, not hang off of an RF stub (Same problem with C15) which that branch will become.   It will also help not having L2/C2 tucked under the shield base during rework.

    Any grounded device pin (critically on capacitors) needs a fanout via as close as possible to the pin.   While a via hole too close to the pad can allow solder paste to disappear during reflow and leave a dry joint, if you tent/plug vias with soldermask, you should be able to bring them closer to the pad. 

    Devices to the upper right of the can need ground vias on the pins. 

    Don't rely on the ground pour for grounding RF devices.   Add more ground vias around the filter module on the right side.  There is usually a suggested layout in the datasheet.  

    You need to put a couple of vias around the shield base pads to make sure you don't cause any resonance problems.

    From someone who works up to 8gHz daily, I hope you can make these changes.

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