Hi Max - Gold and tin do mix in solder! The solubility of gold in tin is quite high and the reaction happens very fast (the gold doesn't evaporate).Give me a call off-line and I can give you some data sources showing the mechanics of what happens. Your right - there are military (and commercial) studies showing the problem with gold in the solder joint but the mechanism of what happens is different than what you described. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: RE: ASSY: Pre-tinning of Gold Leads Author: [log in to unmask] at ccmgw1 Date: 1/15/97 10:23 AM 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 Hope this helps Max Bernhardt Woodward Governor Co. ---------- From: Rajan, Sanjay To: technet Subject: ASSY: Pre-tinning of Gold Leads Date: Tuesday, January 14, 1997 1:45PM Technetters We use a lot of components that come with gold plated leads (gull wing, J-leaded, castellations..). We are currently asking our vendors to pre-tin these leads if possible and one such vendor wants to know the exact mil-spec that he can look up to know the thickess of the tinning that is required. Can anyone point me to the exact document that spits out recommended tinning thicknesses based on the thickness of the gold on the lead?? Thank you ________________________________________________ Sanjay Rajan RF Communications Division Harris Corporation Product Design Engineering 1680 University Avenue Phone: (716) 242-3923 Rochester, NY 14610 Fax: (716) 242-3174 ________________________________________________ ************************************************************************ *** * 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] * ************************************************************************ *** *************************************************************************** * 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] * *************************************************************************** *************************************************************************** * 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] * ***************************************************************************