You are not soldering to gold plating, you are soldering to brass and
berylium copper.  Soldering to these materials without a barrier layer
between the base material and the gold plating is not considered good
practice.  Your results indicate that there is poor to no wetting between
the solder and the base materials.  This is to be expected.  You must
redesign your attachment system to provide the proper barrier layer and
plating to accommodate the hand soldering process.

         Al Cash
         [log in to unmask]
> ----------
> From:         Bruce Robertson[SMTP:[log in to unmask]]
> Reply To:     TechNet E-Mail Forum.;Bruce Robertson
> Sent:         Thursday, June 04, 1998 6:43 PM
> To:   [log in to unmask]
> Subject:      [TN] Soldering to Gold Plated Components
>
> Hello,
>
> We have problems with manual soldering to gold plated components to a
> PCB (auxilliary connector pins and battery contacts). In approx 20% of
> the joints the bond between the solder and the gold plating is of
> unacceptable strength, with some having  failed in service under small
> loads.
> The plating is gold over  brass (pins) or berrilium copper (contacts).
> We are using a 63/37 tin lead solder at the moment. As far as I can see
> there is good wetting of the gold, and the serface of the solidified
> solder
> is fairly bright. I have an idea that there may be a brittle intermetallic
> being
> formed with the gold by either the tin or the lead. Does anybody know
> what the story is with Gold intermetallics?? What would be the solution
> to this? Will using a solder with 2% silver stop the intermetallic
> formation
> at all?
> Any information on soldering to Gold would be much appreciated.
>
> Regards
>
> Bruce Robertson
> Production Engineer
> Tait Electronics Ltd
> New Zealand
>
> ################################################################
> TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
> ################################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in the body:
> To subscribe:   SUBSCRIBE TechNet <your full name>
> To unsubscribe:   SIGNOFF TechNet
> ################################################################
> Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional
> information.
> For technical support contact Hugo Scaramuzza at [log in to unmask] or
> 847-509-9700 ext.312
> ################################################################
>

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################