So it is structural soldering, meaning the probability is that it was soldered with acid flux and water washed. That would give you very adequate wetting and uniformity of results. Not a total certainty because some nickel platings are much easier to solder than others, but post solder flux removal is probably done and water washing would probably be the cheapest , meaning it makes sense to use a water sol flux. OF course there are all sorts possibilities we could speculate on. A contrary one: it is possible a fluxless operation was done on the bare aluminium and then it was plated. Whether automated or not, and how much would depend on the rate of production required and the volumes involved. Not necessarily the exact same thing. 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 Victor Hernandez Sent: Tuesday, September 03, 2013 12:04 PM To: [log in to unmask] Subject: Re: [TN] Solder joint failure This is actual the actual soldiering using a copper heat tube to a nickel plated surface. The solder joint appears very uniform and NOT hand soldering. Therefore I suspect some sort of automatic soldering process. Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Gerald Bogert Sent: Thursday, August 29, 2013 2:41 PM To: [log in to unmask] Subject: Re: [TN] Solder joint failure August 29, 2013 Appears that you are talking about soldering metals to metals and not soldering to electrical components. If this is true, mechanical soldering requirements and not J-STD-001 soldering would normally apply. Is this a soldering or otherwise a brazing operation since many heat sinks are brazed to the copper pipes using dip braze or furnace brazed process rather than soldered. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Whittaker, Dewey (EHCOE) Sent: Thursday, August 29, 2013 3:10 PM To: [log in to unmask] Subject: Re: [TN] Solder joint failure Usually a sacrificial gold is the final finish over the nickel. The fluxes used to solder to nickel are unique. IMHO, no-cleans; not allowed. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Glidden, Kevin Sent: Thursday, August 29, 2013 12:01 PM To: [log in to unmask] Subject: Re: [TN] Solder joint failure In my experience nickel is NOT easy to solder to at all. -----Original Message----- From: Victor Hernandez [mailto:[log in to unmask]] Sent: Thursday, August 29, 2013 2:53 PM To: [log in to unmask] Subject: [TN] Solder joint failure Fellow TechNetters: Should I be concern with an electroless matted nickel plating over an aluminum sheet metal surface and solder onto a copper heat tube? I recall something about directly soldering onto a nickel surface. Beside nickel oxidation. Any suggestions would be greatly appreciated. Victor, ______________________________________________________________________ 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] ______________________________________________________________________ ______________________________________________________________________ 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] ______________________________________________________________________