The PCBs shops can inspect black pads using AOI (Orbotech, Camtec), what is your tool? Best Regards ROKAH Reuven "Zweigart, Siegmund" To: [log in to unmask] <SiegmundZweigart@ cc: HG.SLR.COM> Subject: [TN] Black Pad Detecting Machine Sent by: TechNet <[log in to unmask] IPC.ORG> 19/08/2003 14:04 Please respond to "TechNet E-Mail Forum."; Please respond to "Zweigart, Siegmund" > 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------