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 Round hole, square peg...... 

Last post Tue, Jun 11 2013 7:09 PM by redwire. 8 replies.
Started by TH Designs 11 Jun 2013 05:40 AM. Topic has 8 replies and 979 views
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  • Tue, Jun 11 2013 5:40 AM

    • TH Designs
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    Round hole, square peg...... Reply

     New one to me...........

    I have a board where we have decided to put a few non-plated holes around the board to be used for debug purposes incase we need to run some wires from the bottom layer to the top layer for modifications and such. I have a mechanical hole that when I place it anywhere on the board, the solid copper layers produce a void of a square instead of a circle. I have other holes of similar nature used for the mounting holes that were placed the same way but give me a nice circular void.

    So, why the square void vs the circular void? Both pad stacks have the same structure except the drill diameter is smaller fo one vs the other. Both holes are non-plated and have pad sizes smaller then the drill size so the pads get drilled away.

     

     

    • Post Points: 5
  • Tue, Jun 11 2013 5:59 AM

    • TH Designs
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    Re: Round hole, square peg...... Reply

     

    TH Designs:

     New one to me...........

    I have a board where we have decided to put a few non-plated holes around the board to be used for debug purposes incase we need to run some wires from the bottom layer to the top layer for modifications and such. I have a mechanical hole that when I place it anywhere on the board, the solid copper layers produce a void of a square instead of a circle. I have other holes of similar nature used for the mounting holes that were placed the same way but give me a nice circular void.

    So, why the square void vs the circular void? Both pad stacks have the same structure except the drill diameter is smaller fo one vs the other. Both holes are non-plated and have pad sizes smaller then the drill size so the pads get drilled away.

     

    Example:


    • Post Points: 20
  • Tue, Jun 11 2013 6:07 AM

    • mcatramb91
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    Re: Round hole, square peg...... Reply

    If the padstack has a circular Anti-Pad than the only other thing that I could think of is a Sq Route Keepout/All shape is defined in the symbol which is causing the dynamic shape Sq void.

    Hope this helps,
    Mike Catrambone

    • Post Points: 35
  • Tue, Jun 11 2013 6:27 AM

    • TH Designs
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    Re: Round hole, square peg...... Reply

     Hmmmmm...........

     Pad stack has no antipad defined on any layer. Maybe?

    • Post Points: 20
  • Tue, Jun 11 2013 6:40 AM

    • TH Designs
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    Re: Round hole, square peg...... Reply

     No antipad was defined, BUT no antipad is defined on the other hole that has the circular void.

    • Post Points: 5
  • Tue, Jun 11 2013 6:48 AM

    • TH Designs
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    Re: Round hole, square peg...... Reply

    mcatramb91:

    If the padstack has a circular Anti-Pad than the only other thing that I could think of is a Sq Route Keepout/All shape is defined in the symbol which is causing the dynamic shape Sq void.

    Hope this helps,
    Mike Catrambone

     

     

    Mike,

    Yup, square route keepout defined. Deleted it, now all is well with the world.............. until the next snag.

     Thanks,

    Tom

    • Post Points: 5
  • Tue, Jun 11 2013 6:57 AM

    • mcatramb91
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    Re: Round hole, square peg...... Reply

    The reason I asked you to check if you had a circular Anti-Pad was if you enabled the Padstack option "Mech pins use antipads as Route Keepout", it would use the Anti-Pad feature defined in the padstack as a Route Keepout to void the plane.

    If you don't have Route Keepout defined and have not enabled the Anti-Pad as a Route Keepout in the padstack then the shape void will be based on the drill size using the Hole to Shape spacing check which I believe defaults to 8mils. 

    PS. As I am typing this, I just saw your response that you found the Sq Route Keepout in the symbol, great! - still thought it would be good to close the loop with this follow-up post anyway.

    Hope this helps,
    Mike Catrambone

    • Post Points: 20
  • Tue, Jun 11 2013 7:20 AM

    • TH Designs
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    Re: Round hole, square peg...... Reply

     Mike,

    Sooooo many options, so little knowledge.............

    Thanks for the tip.

    Tom

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  • Tue, Jun 11 2013 7:09 PM

    • redwire
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    Re: Round hole, square peg...... Reply

    TH Designs:

      so little knowledge.............

     

    So true...and an attitude to go with it!!

     

    • Post Points: 5
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Started by TH Designs at 11 Jun 2013 05:40 AM. Topic has 8 replies.