Gold thick film dissolves readily in [high] tin solder. This would not be a high reliability process. I suppose a no or low tin lead-free solder is not under consideration for low MP. The rest of your question is really one for plating/component guy. My 1/2 cent: Plated copper to 400µ" [10 µm] thick probably OK, possibly not - depends a little on the quality/type of the plating, in any case not sure if/how this could be done. My mantra when presented with difficult, wood, unknown or otherwise impossible surfaces to solder is always: when in doubt apply electroless nickel. This makes it into an industry standard finish and as such one for which standard fluxes and solders are available, have known behaviours and process parameters are understood. Nickel is a standard finish for most component manufacturers, or is at least easily accessible as eletroless. Here this would be 4-6µm, then protect with immersion gold [silver if you prefer]. Regards Mike Fenner Bonding Services & Products M: +44 [0] 7810 526 317 T: +44 [0] 1865 522 663 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Julie Silk Sent: Tuesday, November 27, 2012 5:54 PM To: [log in to unmask] Subject: [TN] Termination finishes, Cu thickness under Ag, Au-Pt-Pd I have 2 questions about termination finishes on an SMT ceramic component with castellated joints. One is regarding a Au-Pt-Pd fired thickfilm which was claimed to be suitable for soldering. Does anyone have experience with this finish? It seems like a epoxy-bonding sort of finish, and we think we're getting leaching of the metals into the solder joint -- with no remaining connection to the component. Two is regarding an alternative that plates copper over the Au-Pt that is on the ceramic, then Ag over the copper. Is 200-400 microinches of copper sufficient in this application? With SAC solder, there is concern with copper dissolution, but with an SMT process, that should be minimal. This thickness is below the minimum spec for copper thickness on a PCB after soldering. But this is a component. Any input/thoughts on this? ______________________________________________________________________ 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] ______________________________________________________________________