Hi Richard: Is there a way that you can water soluble liquid mask it before SMT process? It is just an idea, since I do not know the particulars of the total process. Regards, Ramon -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo Sent: Tuesday, July 26, 2005 3:27 PM To: [log in to unmask] Subject: Re: [TN] Cleaning of gold wirebond pads the trick is to avoid contamination of your pad. plasma clean and bond ASAP. If you get solder on the pad, you can forget about bonding .... (even very thin layer of solder)... As for wet acid clean afer SMT... good luck, brave guy... I am chicken out on this one... jk -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Stadem, Richard Sent: Tuesday, July 26, 2005 2:39 PM To: [log in to unmask] Subject: [TN] Cleaning of gold wirebond pads Hi Technetters, I have a wirebond application for a client where we need to perform standard SMT, followed up with a wirebonding application. The process is fairly straightforward, but I do not have a lot of experience doing the wirebonding after the SMT. I am used to doing the wirebonding of the chip and the encapsulation before the SMT, on the opposite side. The question I have is, assuming the wirebond pads may be contaminated with flux or fingerprints in spite of our best efforts to prevent it, is there a good way of cleaning the gold pads after the SMT process is finished, to assure there is no flux or other contamination, and that the porous 40 uinches of soft gold over the nickel base is completely dry in order to achieve a good wirebond? We do not have the capabilities for plasma cleaning, we were wondering if there was another method such as cleaning with the ultrasonic cleaner we have. I have read reports of using a mixture of hydrogen peroxide mixed with DI water or weak sulphuric acid in an ultrasonic bath, but cannot recall where I read this. Any help in achieving clean and very dry wirebond pads would be greatly appreciated. --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------