You also have to add the accuracy of your board shop scoring machine
(position and depth), and the artwork registration to your equation.
This could add 8 or more thousandth's to the 12 you started with.  I use
worst case for clearance to a scored edge (not rss) to make sure no
copper is exposed.

Regards,


> -----Original Message-----
> From: [log in to unmask] [SMTP:[log in to unmask]]
> Sent: Thursday, July 30, 1998 9:42 AM
> To:   [log in to unmask]
> Subject:      [TN] Scoring
>
>      I am looking for input as to what others use as a rule for
> cutting
>      back copper on artworks, to avoid being cut during the v-score
>      operation. It seems that whatever I use, no matter how many times
> I
>      double-check my numbers, we still occasionally get copper being
>      exposed during scoring. If there is a better way than I a using,
> it
>      would be appreciated. I am currently using a formula of the depth
> of
>      the score ( not the web ) multiplied by the tangent of the given
>      angle. Ex : a depth of .021 X 30 degree tangent (,5774) tells me
> to
>      make sure that we are clear at least .012 from the edge of the
> board.
>      If I'm calculating wrong, please let me know.
>
>                                  Thanks
>
>                                  Ernie Smith    [log in to unmask]
>
> ################################################################
> TechNet E-Mail Forum provided as a free service by IPC using LISTSERV
> 1.8c
> ################################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in the body:
> To subscribe:   SUBSCRIBE TechNet <your full name>
> To unsubscribe:   SIGNOFF TechNet
> ################################################################
> Please visit IPC's web site (http://www.ipc.org) "On-Line Services"
> section for additional information.
> For technical support contact Hugo Scaramuzza at [log in to unmask] or
> 847-509-9700 ext.312
> ################################################################

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################