I have heard about gold embrittlement but have not seen any data regarding failure rates, or how long before solder joints are at risk of failing. We use an ENIG finish on all our boards and I'm wondering if gold embrittlement should be something we should be concerned with regarding short and/or long term reliability. If so what precautions can be taken to avoid it?
It looks like, according to IPC-610:
"Gold shall be removed from solder terminals plated with 2.5 um [0.0984 mil] or greater gold thickness."
also, it looks like an acceptable method to remove the gold is to tin the surface and then remove the tinning with solder wick - once being enough to leach out the gold.
Also found this graph:
I still dont know if this would be worthwhile though. Does anyone have experience with gold embrittlement or lack thereof?