It depends Jack.  If you need the full clearance of the holes for the
mounting and conformal coat would interfere with the mating, then you would
specify the unplated hole as a keepout zone and the clearance would depend
on your hardware.

On the other hand, every keepout you put on the board increases the
difficulty and cost of manufacturing.

*Douglas Pauls *| Principal Materials and Process Engr | Advanced
Operations Engineering

*COLLINS AEROSPACE*

400 Collins Road NE, MS 108-101, Cedar Rapids, IA  52498  USA

*Tel:* +1 319 295 2109 | *Mobile: *+1 319 431 3773

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On Thu, Jan 10, 2019 at 3:37 PM Jack Olson <[log in to unmask]> wrote:

> Is it more common to conformal coat unplated mounting holes?
> or designate a clearance diameter on the assembly drawing?
>