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Subject: Re: [Homebrew_PCBs] Holes for screws

From: "Stefan Trethan" <stefan_trethan@...>
Date: 2006-02-08

On Wed, 08 Feb 2006 18:34:19 +0100, Jose Fuentes
<josecarlosfuentes@...> wrote:

> Stefan,
>
> what I was using were pads without copper, but maybe
>
> this is not the best way if I'm going to send this
>
> design to a PCB manufacturer. Also, I found out that
>
> clearance holes must be at least a 5% larger than the
>
> screw diameter. A rule of thumb is to use clearance
>
> holes 10% larger than screw diameter.
>
>
> Regards
>
>
> Jose


The PCB house will usually be fine with that.
In the gerber files my mounting hole is the same as your pad, a large hole
in the drill file and no copper in the copper layers.
I admit i'm not entirely certain what happens with plating if you have
PTH, they will drill the hole first, then plate into it, but when applying
the resist there will be none tenting the hole, so it should be etched
clear again.

ST