I had lived through a green growth similar to this but it was a long time ago (late 1980's early 1990's). It was on gold tabs and gold plated simm sockets. It was caused partially to poor water quality (live bacteria in the water wash although we were originally told it was a DI wash) along with un-activated flux during the manufacturing process. The manufacturing was in a warmer environment, which allowed the bacteria once deposited on the PCB during wash, to grow and feed on the flux residues. When we went to a lab with the boards, they found the bacteria and flux along with a silicon oil. The oil was thought to have come from some maintenance done on the Pick and place machine but this was never confirmed as a factor or not. We just threw everything away and went to a more reputable source that actually had a DI wash and did not leave flux on the PCBs. I also saw another issue like this with some parts from Asia but it was found to be caused by poor air quality that caused the growth to appear blamed on pollution that became entrapped in the case, parts were replaced with same parts different plant with no issues (old style sealed case crystal). Good luck. Kat -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Wednesday, November 14, 2007 1:33 PM To: [log in to unmask] Subject: Re: [TN] Green Growth between PCB traces Hi Everybody! I have Tom's pictures posted. They're at: http://stevezeva.homestead.com/files/GreenStuff2.JPG http://stevezeva.homestead.com/files/GreenStuff3.JPG http://stevezeva.homestead.com/files/GreenStuff4.JPG http://stevezeva.homestead.com/files/GreenStuff5.JPG http://stevezeva.homestead.com/files/GreenStuff6.JPG Those boards look like they've either been slimed or in Linda Blair's bedroom while her head was spinning around! YUCK! Seriously, looks like some sort of dendritic growth to me. I've seen dendrites before, but not green ones... Steve Gregory -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Tom Burek Sent: Wednesday, November 14, 2007 11:44 AM To: [log in to unmask] Subject: [TN] Green Growth between PCB traces Hello everyone, Has anyone ever seen or experienced the phenomenon of this green growth between the traces and even on some of the pads. It almost appears as if it is leaching out from under the etchback of the traces into the space between the traces. Oddly enough it is only on one side of the board, the bottom side, opposite the component side. It will not wash off with DI or Alcohol and a Q-tip, however it will scrub off with a stiff bristle brush or very gently with an exacto knife. The soldermask is very thin in spots, (white solder mask). The PCB is ENIG with white soldermask. FR4 material (IPC-1401/21). The boards had just gone through HALT testing, (Thermal Shock: 2 hrs. @ 85°C then 2 min. 5 sec. swing to -40°C for 2 hrs. This was repeated until it failed after 136 hrs.) We think this green stuff might have caused the failure. With the temperature swings, often there is condensation created so, possibly created by humidity? Is there something in the PCB fabrication process that could have lay dormant until it experienced thermal shock? I know an analysis of the green stuff is necessary, but I was wondering if anyone has ever seen of experienced this type of growth before. Thank you in advance. I have attached some pictures, but I know somehow they are suppose to get to Steve to post. Tom Burek, CID+ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 -----------------------------------------------------