We are making space quality MLBs. We are using hot mounting for micro section. 
My understanding is hot mounting(Phenolic power of Buehler at 150 Deg C ,180 bar &  5 minutes)  of PCB specimen will destroy the PCB specimen Our metallographers are against using cold mounting. The reason  is they claim poor edge retention & high shrinkage   and observing faults are difficult. 

Which method of mounting is best for micro sectioning PCB ?. Which is the best resin & hardener having low shrinkage and high edge retention ?.

regards,

R.Saravanan