As Doug says, whatever you want that meets your needs. It is not by any
means necessary to design in a "dmz of coating" but you can. And it will be
greatly appreciated by your coater.

Honestly, from receiving hundreds of different drawings/specs for coating
application,  the predominant call-out is ..... nothing. Most drawings and
specs only call-out what is to be coating free. For example "Coat board
with IPC -830 approved UR, do not coat J1-J7 and all played mount holes."
It's up to me to decide how close to J1 to get with the coating. I once
coated the leads of all the fine-pitch connectors and the customer said
that was too close. The next customer will reject the work if I don't coat
the leads.

On Dec 6, 2017 10:18 AM, "Jack Olson" <[log in to unmask]> wrote:

> I don't know what staking is, and I think they are trying to avoid
> masking/demasking.
> The goal is to spray everything except the mounting holes and a few exposed
> metal areas that we are using for thermal reasons.
> I was told I need to leave an "overspray zone" as neutral territory between
> those two types of areas
>
> On Wed, Dec 6, 2017 at 9:12 AM, Tan Geok Ang <[log in to unmask]> wrote:
>
> > Staking? Masking / De-masking?
> >
> > ------------------------------
> >
> > *From:* Jack Olson <[log in to unmask]>
> > *Date:* 6 December 2017 at 10:48:41 PM SGT
> > *To:* [log in to unmask] <[log in to unmask]>
> > *Subject:* [TN] IPC-CC-830 (Conformal Coat)
> >
> > What should a designer use as an "overspray zone" for conformal coating?
> > I would like to keep components and vias away from areas that will NOT be
> > coated.
> > I don't know why 3mm sticks in my mind, but I can't find anything in
> > IPC-CC-830 about it
> > (including the new Working Draft)
> > I also downloaded the new Conformal Coat ebook from 007 and can't find it
> > there, either!
> >
>