The datasheet current figures are a joke - no way you can put 186A through a small package like this - MOSFET datasheets seem routinely to use die ratings rather than package ratings for max current. The bond wires will vaporize at 186A. There's significant specs-man-ship on power MOSFET datasheets alas. The datasheet I saw has a note (a) "package limited" but it doesn't appear to be used (so we can assume all the suspect values are die-limited).
To be sensible the package dissipation on a typical PCB is upto 6W or so for 10s only (datasheet) - most people wouldn't put more than 2W through such a package for reliability. That limits the current to sqrt (2/0.0015) = 36A, but again can the bond wires or PCB traces take that continuously? Questionable unless on a 2oz IMS board perhaps.
Anyway current ratings for MOSFETs are always assuming infinite heatsink and the extreme thermal limit - you'd never want to be in that regime continuously - in practice you determine the maximum power dissipation Pd you are happy with (given package and its thermal environment), and determine the max current from I = sqrt (Pd/Ron), using worst case Ron. And if switching rapidly you'd account for switching losses too.
To be sensible the package dissipation on a typical PCB is upto 6W or so for 10s only (datasheet) - most people wouldn't put more than 2W through such a package for reliability. That limits the current to sqrt (2/0.0015) = 36A, but again can the bond wires or PCB traces take that continuously? Questionable unless on a 2oz IMS board perhaps.
Anyway current ratings for MOSFETs are always assuming infinite heatsink and the extreme thermal limit - you'd never want to be in that regime continuously - in practice you determine the maximum power dissipation Pd you are happy with (given package and its thermal environment), and determine the max current from I = sqrt (Pd/Ron), using worst case Ron. And if switching rapidly you'd account for switching losses too.