Your vendor site is totally correct. 2Ag is an excellent solder, but it does nothing to prevent tin and gold from reacting chemically. An earlier poster is correct gold goes into solution in liquid solder very fast, less than a second. Gold and tin form a brittle intermetallic compound that is needle shaped. Since gold is more active than silver, the silver will not do dip in slowing-down that reaction.
It's a good idea to limit gold to less than 3 percent of the solder connection. That's why: * People spent so much time talking about gold thickness in ENIG solderability protection a few years ago. Both IPC-4552 & 2221 give ENIG specifications. * J-STD-001 requires solder dipping of components with gold plated leads.
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