A cross section of the "pimples" should help isolate the cause. If there is copper in the pimple - the problem goes all the way back to board fab - most likely strip and etch. These would have been tight geometries, so incomplete stripping of image film, and resulting marginal etching would leave these copper bumps. They are now covered with nickel. If there is no copper in the bumps, the nickel plating is implicated. It would help to know if it is electroplate or electroless nickel. I suspect electroless - as the pads seem to be for a peripheral lead device. Thus they would have been nickel plated after etching of circuits. Over activation, or dried on activator from an interrupted process sequence might give this pattern. But, I would expect even more extraneous plate - even on top of the mask dams, perhaps. On the chance they were electroplated at the start of the fab cycle, "burning" is the creation of electroplated nodules when the electroplate current density is too high. Do you know the fabrication sequence? Can you get a cross section of a "pimple"? Denny Fritz MacDermid --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------