John, Hmm, not a bad idea although I am not sure other than some sort of surface analysis how I might determine that. I will take a closer look as we do have some unpopulated panels but another thing I forgot to mention in the initial posting is that there are no signs of staining on the boards which we have seen in the past affecting soldering other boards. I am just heading out now so I will look closer tomorrow. Thanks for your interest. John Parsons _____ From: John Burke [mailto:[log in to unmask]] Sent: Tuesday, September 13, 2005 4:32 PM To: 'John Parsons'; John Burke Cc: 'TechNet E-Mail Forum' Subject: RE: [TN] Wanted: Enig Solderability Troubleshooting Help Not sure about the directionality in reflow, the pads even for the unloaded positions seem affected. Have you looked at the possibility that the non wetting may be due to the fact that there was some contaminant in the solution ( water - whatever) and that the reason it is on one side is that that is where it remained when the boards were drying, ie the non wetted parts were the lowest and the solution, whatever it was was allowed to drain, but remained on the lower pad areas where it contaminated the surface as it dried? John Avanex John Burke Senior Manager RoHS Compliance <mailto:[log in to unmask]> [log in to unmask] 40919 Encyclopedia Circle Fremont CA 94538 tel: 510 897 4250 fax: 510 979 0189 mobile: 510 676 6312 <https://www.plaxo.com/add_me?u=4295480015&v0=1019836&k0=1461929701> Add me to your address book... <http://www.plaxo.com/signature> Want a signature like this? -----Original Message----- From: John Parsons [mailto:[log in to unmask]] Sent: Tuesday, September 13, 2005 4:23 PM To: 'John Burke' Cc: 'TechNet E-Mail Forum' Subject: RE: [TN] Wanted: Enig Solderability Troubleshooting Help John, The boards are not full body but conventional ENIG (selective). I have attached two more photos for you to look at. Yes, your observation on the directionality of the problem is accurate for the samples I have. These two last pictures unfortunately were taken with the board orientation rotated 180deg so the nonwetting appears to be on the left side of one and the right of the other. In reality they are on the same side of the board. I make the further observation that if we assume direction of travel through reflow being left to right as you view the photos any components that have the body shadowing the opposite leads, the leading leads seem to be wetted fine whereas the ones on trailing edge are not. If the component body is perpendicular to direction of travel then all leads exhibit wetting issues on the trailing(?) side of the lead. From what we are told not all boards exhibit the problem and during troubleshooting they ran two boards separated by about 10 seconds through the oven and one board was fine the other not (I don't know if the first was go or the second, possible accounting for insufficient recovery in the oven although I do not know if this would be the case as the panel is not that large). They have also tried different solder paste lots with no effect. John Parsons _____ From: John Burke [mailto:[log in to unmask]] Sent: Tuesday, September 13, 2005 3:50 PM To: 'John Parsons' Subject: RE: [TN] Wanted: Enig Solderability Troubleshooting Help Ouch. A couple of questions. Is that full body enig (ie enig under resist) or is it the more normal selective enig (copper under resist) And excuse my paranoia but that non wetting seems to be directions, always to the right side of the pads that you sent photographs of - is that in fact the case? Let me know the answers by return please. John Avanex John Burke Senior Manager RoHS Compliance <mailto:[log in to unmask]> [log in to unmask] 40919 Encyclopedia Circle Fremont CA 94538 tel: 510 897 4250 fax: 510 979 0189 mobile: 510 676 6312 <https://www.plaxo.com/add_me?u=4295480015&v0=1019836&k0=1461929701> Add me to your address book... <http://www.plaxo.com/signature> Want a signature like this? -----Original Message----- From: John Parsons [mailto:[log in to unmask]] Sent: Tuesday, September 13, 2005 3:43 PM To: 'John Burke' Subject: RE: [TN] Wanted: Enig Solderability Troubleshooting Help John, Thanks for your offer of assistance. These are screen shots of rather larger pictures. Not quite the resolution I would like but it seems the best we can do with our equipment. I could send the originals but they are about 2.5-3M each. Regards John Parsons _____ From: John Burke [mailto:[log in to unmask]] Sent: Tuesday, September 13, 2005 3:33 PM To: 'John Parsons' Subject: RE: [TN] Wanted: Enig Solderability Troubleshooting Help John, I believe on that finish I have seen it all.....................8-) Please send me the images directly, I would be please dto help if I am able, John ------------------------------------ Avanex John Burke Senior Manager RoHS Compliance [log in to unmask] 40919 Encyclopedia Circle Fremont CA 94538 tel: 510 897 4250 fax: 510 979 0189 mobile: 510 676 6312 ------------------------------------ -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of John Parsons Sent: Tuesday, September 13, 2005 3:26 PM To: [log in to unmask] Subject: [TN] Wanted: Enig Solderability Troubleshooting Help We are trying to help a customer resolve a solderability problem they are seeing on some boards they have received from an off-shore vendor. Prior to recent batches approx 8-10k boards have been received and assembled without incident from the same vendor. As a fabricator ourselves we have seen very little in the way of solderability issues (knock-on-wood) with our ENIG so I am not sure what steps we should take next. We have received 4 panels for troubleshooting each with 4 images per. Two panels exhibit good solderability and two do not. We have measured Au and Ni using XRF on all panels and results for Ni are in the 200u" range with gold being just under 2u". I have cc'd Steve on this posting with attached pictures in hopes that he can post them. Should the boards be sent out for surface analysis? If so, which labs do such work? A recent thread mentioned EDS results are not always sufficient and that ToFSIMS is the way to go. Any insight as to which direction should be taken would be appreciated. Regards, --------------------------------------------------- Technet Mail List provided as a 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 847-615-7100 ext.2815 -----------------------------------------------------