very Low level signal routing (sub-micro volts and fA’s)

[smith_suez]

Hi ....
I was just wondering what all precautions we have to take while routing very low voltage signal traces (sub-micro volts and fA’s) .Also what are constraints regarding layout, power lines and decoupling supporting that.

Thank you so much in advaNCe!!

 

[fala]

use multi-layer board heavily guard it, use as wide as possible tracks, still you need a hell lot of luck...