shelf life and wirebondability, if you have high density device on board, both are critical. my 1.45 cents. don't know anything about uyemura. never heard about it. jk > Hi > > Could that relate to the Uyemura TWX-40? Supposedly a hybrid bath for > plating thicker gold without damaging the nickel? > It doesen't make sense for manufacturers to apply thicker gold electroless > when they can use a simpler immersion process, why would anybody do that? > > BR > Grunde > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Guy Ramsey > Sent: 12. august 2015 13:02 > To: [log in to unmask] > Subject: Re: [TN] immersion silver > > Very interesting addition to this discussion. > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer > Sent: Tuesday, August 11, 2015 5:16 PM > To: [log in to unmask] > Subject: Re: [TN] immersion silver > > Hi Joyce- > > I thought perhaps someone smarter than me would give a carefully thought > out response to your intelligent question, but it seems it was ignored, or > went into my auto-junk machine, or maybe I've gone blind. > > Anyway, at some point in the 2000's the definition of "Immersion plating" > got changed. I believe this happened because the immersion plating of your > definition was extremely easy to use and care for. So people asked for > "immersion" and the salesmen started claiming that finishes were > "immersion" > when they were actually "electroless" (which are a pain in the rear to > apply, manage, and dispose of). I think Uyemura was the first to do this, > advertising a thick "immersion gold". I remember going to their booth at > IPC that year and trying to figure out what was going on, and when I did > my impression was the salesman hid behind the "language barrier". > > So "immersion" now means any plating which uses no electrodes, and is put > on "kind of" thin through careful process control. > > Wayne > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo > Sent: Tuesday, August 11, 2015 12:08 PM > To: [log in to unmask] > Subject: Re: [TN] immersion silver > > gurus, I need some education: Immersion process what I know of is surface > ionic exchange process, once it covered surface, the chemistry stops, so > it is a self limiting process. What is thin and thick? you means it can > really gets thicker like electroless type? not self limiting? Many > thanks. > Best regards, > jk >> From memory the "thin" and "thick" silver finish classes recognised >> that there were two competing but roughly equally popular IAg >> chemistries in the industry , each with their own process max-min >> deposit thicknesses and one typically thicker than the other. >> >> Clearly it didn't make sense for an IPC spec to have a "barn door" >> range from minimum "thin" to maximum "thick", hence two ranges >> defined. I don't recall one being "better" than the other because of >> the thickness >> > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________