As soon as nickel is deoxidised you don't need a flux to solder it with tin. The two metals alloy easily. If you talk about aggressive flux you mean a flux which is able to reduce the stable nickel- oxide. To me it seems as if the nickel surface is coated to prevent oxidation as it is done with gold on the PCBs. Since it looks as if this protection is invisible it must be very thin and yet it seals off the oxygen. Or the nickel is covered with a passivation layer which can be cracked with a mild flux (Ni- anything which is less stable than NiO but stable enough that the Oxygen is not replacing the anything over time).


Regards

Günter 




> -----Ursprüngliche Nachricht-----
> Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Vladimir Igoshev
> Gesendet: Donnerstag, 13. August 2015 15:06
> An: [log in to unmask]
> Betreff: Re: [TN] Solderable Nickel?
> 
> We are on the same wavelength then:-). In essence, everyone literally solder
> either to Cu or your Ni.
> 
> There are only two ways of soldering to Ni I can think of: either have a rather
> strong flux (as you pointed out), or have something like "OSP" preserving its
> surface. ‎I've never heard of such thing though but it doesn't mean it can not
> exist.
> 
> 
> Regards,
> 
> Vladimir
> Sent from my BlackBerry 10 smartphone on the Rogers network.
>   Original Message
> From: David Hillman
> Sent: Thursday, August 13, 2015 08:53
> To: [log in to unmask]
> Reply To: TechNet E-Mail Forum
> Subject: Re: [TN] Solderable Nickel?
> 
> Hi Vlad - let's characterize nickel this way: in general, nickel is solderable with
> the aggressive fluxes. The majority of the flux formulations used by many of
> the High Performance OEMs are ROL0 materials which traditionally were not
> very compatible with nickel surface finishes.
> The flux formulations being used are not aggressive. So I have the some
> question as Ben - what's different about these new "solderable nickel"
> surface finishes? I have subjected them to 150C bake for 4 hours and they
> meet the IPC-JSTD-002 testing criteria. Pretty impressive.
> 
> Dave
> 
> On Thu, Aug 13, 2015 at 7:27 AM, Vladimir Igoshev <
> [log in to unmask]> wrote:
> 
> > Ni in general is solderable. The clues to on is "for how long"! Are
> > you sure the parts font have a thin layer of Sn over Ni?
> >
> > ‎Regards,
> >
> > Vladimit
> >
> > Sent from my BlackBerry 10 smartphone on the Rogers network.
> > Original Message
> > From: Gumpert, Ben
> > Sent: Thursday, August 13, 2015 07:35
> > To: [log in to unmask]
> > Reply To: TechNet E-Mail Forum
> > Subject: [TN] Solderable Nickel?
> >
> > TechNetters,
> >
> > I've received several components recently that were plated with
> > 'solderable nickel' and to my surprise they soldered just fine (using
> > a
> > ROL0 flux).
> > Anyone know what is going on to keep the nickel from oxidizing?
> >
> > Ben
> >
> >
> __________________________________________________________
> ____________
> > 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] 
______________________________________________________________________