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
-----------------------------------------------------