Elisabeth and Christian, If you have any questions about the ENIG process itself I am sure I can answer some questions for you. I have done 2 installations using the Uyemura chemistry and we are currently running the ENIG process for 2+ years. Feel free to contact me. Tony Steinke AIT-Atlanta Inc. [log in to unmask] ----- Original Message ----- From: "Zweigart, Siegmund" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, August 19, 2003 7:04 AM Subject: [TN] Black Pad Detecting Machine > > Hi all, > > > > we are two students named Elisabeth Stumpf and Christian Wuerfel studying > > at Solectron Herrenberg in Germany. > > In the context of our studies we are currently working on a project to > > investigate the potential market for > > a machine which is designed by Solectron. This machine shall detect Black > > Pad infected PCBs before being assembled > > and without destruction of the PCB. > > > > The prototype is now under construction. Afterwards function tests will be > > made, by which the operativeness of this machine > > is checked > > > > What is Black Pad? > > > > Black Pad is described as the corrosion of immersion gold-plated, > > elctroless nickel ( ENIG). > > > > Thereby interconnection failures occur after final assembly of the PCBs > > due to a poorly formed joint at the solder/nickel interface. > > When the suspect joint is stressed, the connection is easily broken, > > leaving an open cicuit. > > In other cases, the pads are dewetting during the soldering process.The > > dewetted pads are discolored black, which lead to the > > nomenclature BLack Pad. > > > > Investigations on Black Pad show that a corrosive interlayer between the > > gold and the nickel causes it. It is an insidious > > problem, since this interlayer is covered by gold and therefore, it has > > been not able until now to detect Black Pad by > > non-destructive methods. The symptoms of Black Pad only occcur after > > soldering which causes high costs since the PCB > > and the assembled componenets have to be scrapped. > > > > > > Elisabeth`s and my job is to decide if this machine can be successul. > > Therefore we need your support. > > If you are interested in our topic we would like to contact you personally > > and ask you some questions. > > Of course we let you participate in our results. > > > > We would be very grateful for your answers! > > Thanks a lot in advance. > > > > Elisabeth and Christian > > > > > > --------------------------------------------------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8e > 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/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 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 -----------------------------------------------------