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Via pads in inner plane layer.

Prasanna

hi all,

I got a question.  I am designing 4 layer board having TOP,GND ,VCC,BOT layer.  Vias which I am using are having pads in inner layer even it's not connected to that layer. It's having enough clearence but Is it ok to use vias in such way? i can edit those vias in Pad designer. suggest me which one is right.

 

 prasanna hegde

  • oldmouldy

    Unless there is a good reason to remove the inner pads, it is generally better to leave the pads there, proper design rules will ensure the required clearance.

  • Prasanna

    hank u oldmouldy......

    I used do the same ... but today i saw some other design in which they have not used Via pad in inner layer.

    can you tell me how to upload screen shot  or snap in our post?

     

     

    Prasanna

  • redwire

    You don't need the pad (necessarily) but there are several ways to approach this.  If it's a signal via from TOP to BOT then you can use a standard via with pads on all layers but then in the artwork control, choose to turn off unused pads.  

     If you choose to build a custom via then you still need the required drill clearance on the unused layers.  Check with your fabricator on what the minimum antipad would need to be.

    And then there's the whole issue of signal return current when switching from a VCC referenced signal to a GND reference signal. :)

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