Good Morning! Send me your fax number and I'll send you the Pb/Sn/Ag ternary phase diagram (are you sure you really want to read it!). Do you want a particular isotherm? I understand the direction you are coming from for the melting point but I think the practicality of it is a stretch. To have some predictability you would need the "system" which would be the composition of the added solder plus the base solder to be fairly set, solder volume quantities fixed, temperatures involved stable, etc - none of these factors are easily controllable on the manufacturing floor and/or would cost quite a bit to be controllable. Also depending on how long the solder joint is in the liquid state you would have several diffusion reactions occurring simultaneously which would be really fun to predict! Consider soldering to a gold surface - if the solder joint composition moves toward the gold/tin side of the ternary you would expect the melting point to go up but folks solder to gold everyday on product without having a problem. Let me know your fax number and Good Luck! Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: ASY: Alloy contamination Author: [log in to unmask] at ccmgw1 Date: 2/5/97 10:38 AM Here's one for the metallurgist. I have been unable to locate a Pb93.5/Sn5/Ag1.5 (305C liquidus; 309C solidus) ternary phase diagram to date. I have been told that one of the technical issues is simply soldering to SnPb plated and/or SnPb hot-dipped coated components with this PbSnAg solder will realize a drop in the melting point. My question is how much ? Assuming, for instance a lead finish composition of Sn63/Pb37 with solder coat thickness of 3 to 4 mils or a CERDIP package with leads that are 100% Sn electroplated (200 to 500micons). *************************************************************************** * 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] * ***************************************************************************