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
################################################################