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 ################################################################