DRV8825EVM: Thermal issues in Multi layer PCB

Part Number:DRV8825EVM

Hi team,

we used DRV8825 driver, It is working fine in independent module of the drv8825 driver.

Now, we go to integrate all other module in One 6 layer PCB.so please help us how to taken care the thermal issues in multi layer for DRV8825 driver? 

DRV8825 Driver specification: Shunt resister is 0.2ohm, Vref = 1v ,Stepper motor each winding is current is = 0.8A.

independent module worked fine in open loop (more than 1 hour),But some heat is getting ,i thought it impacting in close loop device without thermal protection.

So please suggest me how to taken care the thermal issues in multi layer? 

Thanks 

Krishna