How to determine the number of vias on PCB？

[EEbaby]

I am designing a PCB for an IC circuit. The device handles 2W power.
How could I determine the number of required vias under the device package?
Should I put as much vias as possible to dissipate the heat quicker?

Thanks!

 

[c_mitra]

Should I put as much vias as possible to dissipate the heat quicker?

The short answer, YES!

The long answer: IT DEPENDS.

It depends on the available area on top side and the bottom side that can help cooling.

If the allowed temp rise is small you need to consider convection cooling from the exposed (not covered) pads. If the temp rise is high, you need to consider radiative cooling too.

Without going into details, say about 40% of the centre area under the device should be used up by vias.

Under steady state conditions (when the device temp has stabilized under a fixed ambient temp), all the heat produced by the component must be transported on the other side...

 

[marce]

IPC-7093
The device data sheet.