A question,

Are there any reports or IPC data which details the minimum amounts of 
electroless nickel needed to provide a sufficient barrier to copper migration 
and the minimum amounts immersion gold needed to provide sufficient plating 
finish.  

Concerns are solderability failures and corrosion of components.

Annmarie Rainford
Merix Corporation
Forest Grove, Oregon  97116
503-359-9300 x74426