Mark,

Can't speak for all shops but of the three or four that I have
worked for, front end CAM removes the customer added
shearlines (crop marks) and we add our own farther from
the actual board end.  These added borders are for masking,
plating separation, etc.  If the added shear lines on any
tracking layer were mistakenly identified as tracks, the
design rule check would find them as unterminated traces.
This is how most shops do it.  Hope this has been some
help.

Anne Ledger
EMDS, Inc.

> -----Original Message-----
> From: Mark Holmes [SMTP:[log in to unmask]]
> Sent: Thursday, April 27, 2000 7:47 AM
> To:   [log in to unmask]
> Subject:      [TN] Board Outlines in Gerber
>
> Hello all!
>
> What do all you 'front-end' guys like to see in the Gerber files for
> board
> outlines?
> I tend to include the board outline on all layers for my check plots
> so I
> can see
> what's what. Would you rather the board outline on only one layer?
> What
> about
> targets - or do you prefer to add your own. I worry about any outline
> being
> accidentally
> left on a tracking layer and causing shorts (e.g. edge connector pads
> close
> to a board
> outline) This has never happened to me, and when I have spotted that I
> have
> left the board
> outline turned-on on a tracking layer in the past, and spoken to the
> board
> supplier, I was assured
> that they had removed the outline. So I may be worrying about nothing.
> I
> would be grateful
> for any comments though.
>
> By the way, thanks to all those who have responded to my posts in the
> past.
> This forum
> is a terrific source of info, and it's great to hear other opinions.
>
> Best regards,
>
> Mark.
>
> Mark Holmes PCB Designer
> Helvar Merca Ltd.
> Hawley Mill, Hawley Road,
> Dartford Kent. DA2 7SY
> Tel: 01322 22 22 11
> Fax: 01322 282 286
> mailto:[log in to unmask]
> http://www.helvar.com
>
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