Heavy Copper Board does not have a set of definition per IPC. According to PCB industry, however, peopel generally use this name to identify a printed circuit board with copper conductors 3 oz/ft2 - 10 oz/ft2 in inner and/or outer layers. And Extreme heavy copper PCB refers to 20 oz/ft2 to 200 oz/ft2 printed circuit board.
Heavy copper normally used for a various products but not limited to: high power distribution, heat dissipation, planar transformers, power convertors, and so on.
Capability of Copper Clad Board
Base material: FR4/Aluminum
Copper thickness: 4 OZ~10 OZ
Extreme Heavy Copper: 20~200 OZ
Outline: Routing, punching, V-Cut
Soldermask: White/Black/Blue/Green/Red Oil
Surface finishing: Immersion Gold, HASL, OSP
Max Panel size: 580*480mm(22.8"*18.9")