Oh Ingemar! I bet you use your plasma cleaner to scope it out too! Oxygen plasma specifically for presence of organics, and argon-argon/hydrogen for just about all else. Anil - interesting comments. Does a good plater have the ability to 'filter out' the free cyanide and organic soup?? Steve Creswick - Gentex Corporation -----Original Message----- From: Anil [mailto:[log in to unmask]] Sent: Friday, August 13, 2004 6:39 AM To: [log in to unmask] Subject: [TN] Hard Gold Plating/Contaminate Question Hi Gold attracts me again. Codepoits - yes. The gold bath accumulates organic not only from additive decomposition but also leaching out from solder resist and dry film due to free cyanide and other chemicals in the bath and this organic builds up over time. Platers do not discard baths easily owing to loss on Gold. But bond slippage/ problems also come up due to hardness of the gold. anil -----Original Message----- From: Ingemar Hernefjord (KC/EMW) [mailto:[log in to unmask]] Sent: Thursday, August 12, 2004 7:25 PM Subject: Re: Hard Gold Plating/Contaminate Question Forgot to tell you my primitive way of in-room-check-when-operator-is-waiting. I give the surface or one or two strikes with a cottonpin dipped in aceton. If that changed the bondability significantly, then I suspect a contamination. If that doesn't change, I'll give the surface some good strikes with a hard rubber (the kind you used for machinewriting), if that helped, I have a mechanical problem, namely the asperity or the hardness of the surface, which are both oftenly overlooked. These two stoneaged methods were given to me by a guy at Honeywell (he served 40 autobonders). Regards / Ingemar -----Original Message----- From: Ingemar Hernefjord (KC/EMW) Sent: den 12 augusti 2004 10:25 To: 'TechNet E-Mail Forum'; [log in to unmask] Subject: RE: [TN] Hard Gold Plating/Contaminate Question Dave, we had a messy situation with goldplated boards some years back. You and a number of TNs assisted me then, and got my 190 page report on CDROM. Now, we asked ourself same as you do now, and to make long story short, we used TOFSIMS to get a good map of all ions present on and in the gold plate. We found a lot, man! My illusion of pure gold became..just another illusion. But, on the other hand, I also realize what is quite normal. Hydrocarbons and other carbons were present everywhere! Can send you some pages offline, just to give you an idea. Refer to my 292/15961-FCK 115 17. But, to become a serious 'lubricant' (as Harman names it)that disturbs the wirebonding, is oftenly not the real disaster, as the pressure per/microunit is high enough to create those numerous microbonds. Compare with anisotropically adhesive bonded BGAs. The metal particles, that are members for the electrical connection, are literally swimming in 'hydrocarbons', but after curing, you have milliohm resistance from BGA ball to PWB. We saw 'CH' ghosts everywhere, now we feel that such nanolayers are oftenly unavoidable, and that they are not the primary source of failure. Growing to micron-thickness, the situation is, of course, changing, but with growing thickness you need no advanced equipment for the analysis. (Maybe you can borrow the CD from some of them who got it: David D, Werner E, William C, Jack C, Ryan G, Kathy K, Georg W, Steven C, whoever is closest to you.) Ingemar -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of David D. Hillman Sent: den 11 augusti 2004 22:01 To: [log in to unmask] Subject: [TN] Hard Gold Plating/Contaminate Question Hi TechNet! Hey, looking for some help (Rudy, Frank, Gerard, plating folks). Background: I have a test board which with approximately 80 uinches of wirebondable hard gold plating that is having gold wirebond process problems. An XPS (xray photoelectron spectroscopy) analysis of a "good" versus "bad" test board revealed that the "bad" has significant organic surface contamination for carbon and oxygen in the form of a hydrocarbon (lots of C-C and C-H bonds). Now the question: can/will a hydrocarbon species be codeposited into the gold plating thickness? I understand the surface process/issues but the codeposit question came up. Dave Hillman Rockwell Collins [log in to unmask] --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------