You are already using the best fiducial dimensions. Every SMT machine should be able to recognize it. but, A doughnut pattern will look no different than a plated through-hole, So... As an experiment, find the coordinates of a random through-hole and tell your operator (modify the data file if you need to) that coordinate is the new fiducial. I would bet a lunch that he can't "see" it any better. I'm always hesitant to change designs to non-standard just to solve a temporary problem (unless the product will be obsolete within the year?) best wishes, Jack On 10/6/06, Heather Gregg <[log in to unmask]> wrote: > > I'm being told that our Fuji CP-7 is having trouble reading the board > fiducials. The cause is said to be a build-up of too much SN100 plating > on the fid. We currently use a simple dot fid. The dot is 1mm in > diameter and it is made so that there is a 0.25mm ring of bare board > around it before you get to the solder mask. Our PCB supplier has > recommended going to a doughnut design, but our SMT department is > skeptical that this will solve the build-up of SN100 issue. Personally, > I'm not convinced that it is not a problem with the machine vision system. > > That being said, I'm wondering what the "best" fid design would be. What > are/ where can I find recommendations for fids? Does anyone else have > experience with this sort of problem? Should the fid be covered with > solder mask? What design is the most robust in regards to minimizing the > effects that processing variables cause (such as plating build-up, > uneven plating, camera lighting bumped out of alignment, etc.)? > > Inquiring mind, > Hg > > > --------------------------------------------------------------------------------- > 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 temporarily stop/(restart) delivery of DesignerCouncil send: SET > DesignerCouncil NOMAIL/(MAIL) > Search previous postings at: www.ipc.org > On-Line Resources & Databases > > E-mail Archives > Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16for additional information, or contact Keach Sasamori at > [log in to unmask] or 847-615-7100 ext.2815 > > --------------------------------------------------------------------------------- > --------------------------------------------------------------------------------- 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 temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL) Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ---------------------------------------------------------------------------------