Max Bernhardt states...

Gold and Tin do not mix in Solder.  In fact, studies done by the
military actually show a degradation in reliability for gold plated
parts that have been soldered into a board.  My guess is that when the
vendor tins the gold leads, the gold evaporates and you would be hard
pressed to find any of it even if you scraped the tin off.  Therefore,
the guidelines that I would follow would be the industry standard on the
thickness of tin plated leads of components

........

Actually the gold is soluable in the solder.  Try to solder a fine
gold wire to something sometime!  When the gold exceeds 2% of the
tin/lead/gold mixture, the solder becomes brittle.  What you are actually
doing when you tin gold-plated leads in the solderpot is disolving the gold
in the huge volume of solder in the pot.  The resultant plating on the leads
still contains some gold, but a VERY small percentage.  The solder pot
has the same gold content.  Presumably, if you tinned a zillion parts and never
replenished the solder in the pot, you could get high concentrations 
of gold in the solder pot.

Gary P.

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to:           *
* [log in to unmask] with <subject: unsubscribe> and no text.        *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************