  The DarkSide-20k collaboration is preparing to equip 20 m^2 of SiPMs working
in liquid argon at 86 K for the direct search of WIMPs. The collaboration had
to solve many technological aspects, such as the development of SiPM optimized
for operation in liquid argon, the readout of large SiPM-based detectors, the
reliable packaging of more than 200000 SiPMs using radiopure materials. The
packaging solutions available for cryogenic applications and the performances
of the newest cryogenic extended gain SiPMs from FBK will be discussed.
