I asume these are FR4 boards. What you are trying to do is get the best contrast between fiducial and the Board surface. A nice shiny (White as the vision system sees it) fiducial is best. Some HASL fiducials have a small dimple in the center that can cause the P&P machine to reject it. Use the vision system to teach a new fiducial from the boards that are failing. There are various lighting techniques to help in the vision system recognition. Make sure the fiducial is symmetrical. Try teaching a pad or another fiducial on the board to see if you can get repeatability. Some times you can "hit" the fiducial with a soldering iron (no wick) to reflow for solder consistency. You can also try burnishing (Clean with a pencil eraser -preferably the white rubber kind) the fiducial. I would try reteaching the fiducial or try a different (component) fiducial. Remember what you see is not what the vision system sees. What you think may be good may fail. Cal ACI °-----Original Message----- °From: TechNet [mailto:[log in to unmask]]On Behalf Of Mark Hargreaves °Sent: Tuesday, August 21, 2001 7:57 AM °To: [log in to unmask] °Subject: [TN] P&P can't locate fiducials ° ° °Hi All, °We've made boards for a customer for a few years. They've been very °satisfied with HASL finish. Last month they started rejecting °approx 40% of °boards received (3 lots) because their P&P camera couldn't locate the °fiducials. The coating looks typical to us (thickness & smoothness). °Customer can't see any difference between good & bad boards until °they're on °the P&P machine. They say they haven't changed equipment, processes or °operators. We say the same. No HASL hassles from other customers in this °time period. We tried reworking by wicking solder from the fiducials. °Customer rejected approx. 20% for the same reason. They also say that °boards from another vendor are working fine. °Any comments/ ideas? ° ° °Mark ° °------------------------------------------------------------------- °-------------- °Technet 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 Technet °To temporarily halt delivery of Technet send the following °message: SET Technet 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 °------------------------------------------------------------------- °-------------- ° --------------------------------------------------------------------------------- Technet 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 Technet To temporarily halt delivery of Technet send the following message: SET Technet 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 ---------------------------------------------------------------------------------