There is really no set definition of what constitutes a Heavy Copper PCB. General,in the industry label PCBs with 3 or more ounces of copper on the inner or outer layers as a heavy copper PCB.
MOKO have made many type heavy copper pcb and extreme thick copper PCB for Customer.
such as inner layer 8 OZ, out layer 40 OZ(1.05mm).
Heavy copper Printed Circuit Boards( PCBs) Application:
High power distribution boards
Power distribution junction boxes (automotive)
Heat dissipation product
DC to DC power converter
Power amplify Module
Heavy copper Printed Circuit Boards( PCBs) Capability:
Finished PCB thickness: 6.5mm Max.
Inner copper layer: 20 OZ
Outter Layer : 40 Oz
Solder mask: Green/Blue/Black/Yellow..
Surfact treatment: HASL Lead Free, OSP, ENIG, Immersion Silver