From: Kelly Kovalovsky, PCS Engineering ~ EMail:[log in to unmask] ~ Phone:607-757-4595 FAX:607-757-4621 Subject: polishing fiducials I have seen where a 0.016" copper dot fiducial will take HASL such that the solder is extremely domed. The dome will reflect light depending on the solder skew and cause fiducial recognition problems. One fix is to make a larger copper dot. A better fix is to design the fiducial as a copper donut. Let the optics look for the opening (the donut hole), which will always be laminate material. The laminate will provide a consistent surface, assuming you are not routing circuitry through the area on the internal. I know that the Panasonic equipment manuals offer a variety of fiducial designs that work with their equipment. IBM Microelectronics Division 1701 North Street IMAD:FKFE Endicott, NY 13760-5553 *** Reply to note of 11/13/96 10:06