Agree fabricators must push back when they see conductors near a routed or drilled edge.

I have attached a real life example I had yesterday (Ipc-6012 class 3A board)   The conductor is 2 mils from a NPTH on polyimide material. Ergo: max halo is 1 mil....   I asked that all such conductors be shaved or moved to provide at least 15 mils and the customer agreed.

Mike Hill

-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Jack Olson
Sent: Wednesday, December 09, 2009 7:05 PM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] FAB: Acceptability of Haloing

but people are putting planes 4-5 mils from the board edge now.
Is 2mil of haloing really drastic enough to review?

Or from the other side of the coin, any fabricator who sees that
a designer has put conductors that close should immediately put
the job "ON HOLD" for review until implications are discussed?

I'm not disagreeing with you, but that's the problem...

Jack

On Wed, Dec 9, 2009 at 5:55 PM, Gandhi, Mahendra S (AS) <
[log in to unmask]> wrote:

> All Haloing condition must be reviewed with electrical design activities
> to make a decision of acceptance when it is over 50% from edge to
> conductor.
>
> Mahendra
>
> -----Original Message-----
> From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Jack Olson
> Sent: Wednesday, December 09, 2009 2:24 PM
> To: [log in to unmask]
> Subject: [IPC-600-6012] FAB: Acceptability of Haloing
>
> Fabricators,
>
> This is an opportunity to influence the acceptability of your product!
>
> The IPC Standards Development Committee is working on the next
> revision to IPC-A-600 (Acceptability of Printed Boards) which is a
> visual reference companion to IPC-6012.
>
> One of the items we are currently discussing is the acceptability of
> haloing along the board edge. Here is a link to where we stand now:
>
> http://frontdoor.biz/PCBportal/IPC-A-600H213.jpg
>
> The problem is, if the designer violates the recommendation in the
> current IPC-2221 design guideline and puts traces or planes too close
> to the board outline, with the current wording of "whichever is less"
> your boards can be considered rejectable with even a very small
> amount of haloing. Even intentional features like edge fingers can
> make your boards rejectable.
>
> We aren't sure if we should reword this (and if so, how?)
>
> So the ball is in your court (because unless there is a logical
> consensus
> we probably won't change it).
> I'll compile and submit any responses to the next committee meeting.
>
> Jack (aka "the new guy")
>