Jack,

As an OEM, we view the existing wording as what is needed.  If haloing 
would be an issue, then the PCB fabricator should notify their customer 
of whatever traces or features are too close to the board edge.  OEM 
approval allowing boards to be built with haloing encroaching on 
circuitry should be documented.

Regards,

Karl Sauter
Sun Microsystems, Inc.


Jack Olson wrote:
> 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")
>