Hi all, Let me just drop my two bucks worth. I think (and apply) that one "local" fiducial should be fine for most picknplace machines (not all, of course). I'm not sure I get the "rotational accuracy" needing two. You should be getting the "rotational accuracy" (if this is what you mean) from the two (and often times three) "global" fiducials placed on the board. A single fiducial placed locally per device, and often times grouped for cells should be acceptable. Also, I only go with local fiducials on parts with pins on less than .025" (.64mm) pitch. Some might question the .025" parts, but I don't place fiducials on them. Just me. Mitch Sr Hardware Engineer ---------Included Message---------- > Date: Fri, 26 Jan 2001 16:15:25 -0800 > From: "[log in to unmask]" <[log in to unmask]> > Reply-To: <[log in to unmask]> > To: <[log in to unmask]> > Subject: Re: [DC] DC IPC Design rules for Fiducial clearances > > > My two cents, I would agree with Cyrus, there, to my knowledge, > is no use > > for the > > fiducials after placement is done, the only reason to go with either > > one fiducial under the part or two fiducials on a diagonal, (as far as I > > know) > > would be to increase the speed at which the machine could align and place > > the parts. > > The advantage of 2 fiducials is rotational accuracy as opposed to > just locational for 1 fiducial. > > > Dave Farthing > Gordian Design Services > > direct any spam to: [log in to unmask] > > --------------------------------------------------------------------------------- > DesignerCouncil Mail List provided as a free service by IPC using LISTSERV > 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF DesignerCouncil. > To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil > NOMAIL > Search previous postings at: www.ipc.org > On-Line Resources & Databases > > E-mail Archives > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > --------------------------------------------------------------------------------- > ---------End of Included Message---------- _____________________________________________________________ Tired of limited space on Yahoo and Hotmail? Free 100 Meg email account available at http://www.dacafe.com --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------