Don : What is the best shape of fudicials relative to size and configuration? Normally I've seen circle with 1mm dia ( 40 mils ) Also if the board has HASL on all of the pads, can the fudicials be of different material other than HASL? By the process I believe is not usual unless they mask the fiducial before HASL but this can be cost add to the board. We are having a problem with reflective light causing a lot of rejected boards. This is also causing down time. What is the industry using for this technolgy. We have DEK 265 printers and Philips and Siemens placement machines. Normally fiducial are tought to machine using a gray scale level. Up 255 levels are accepted by the vision system, there is a treshold level that determines what is black and what is white. This value is keep recorded with the machine like a reference for all other fiducials. When the machines load the board and target the fiducial, basically it's compared the image with the reference value, sometimes when you change a batch of boards or use old boards from stock you start facing recognition problem. One solution could be re-teach the fiducial using one board of the new batch in this way you will keep one reference more compatible with this new batch. Using eraser to clean fiducial sometimes is effective but requires more labor. By the other side vision system has been upgraded to suport better HASL fiducial, there is lightning conditions to avoid shadowing effect caused by irregular surface. My Philips machines ( Topaz and Emerald ) are capable to reduce "noise" from fiducial image, using diferent light spot ( they call inner and outer filters ), also you can see at monitor what the vision system is really "reading" from the fiducial and give you information about center position, perimeter, etc... I hope this help . Jorge Dourado de Santana Maintenance / Process Engr Microtec - Brazil > -----Original Message----- > From: Steffen, Don E [SMTP:[log in to unmask]] > Sent: 24 de Setembro de 1999 16:09 > To: [log in to unmask] > Subject: [TN] Fudicial Shape > > Technetters > > What is the best shape of fudicials relative to size and configuration? > Also > if the board has HASL on all of the pads, can the fudicials be of > different > material other than HASL? We are having a problem with reflective light > causing a lot of rejected boards. This is also causing down time. What is > the industry using for this technolgy. We have DEK 265 printers and > Philips > and Siemens placement machines. > > Donn E Steffen > Senior Quality Engineer > VDO Control Systems > Auburn, IN 46706 > Phone (219)925-8887 > Fax (219)925-8710 > Email: [log in to unmask] > > ############################################################## > TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for > additional > information. > If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or > 847-509-9700 ext.5365 > ############################################################## ############################################################## TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################