Definition
Heavy copper, or thick copper, is the use of 3 oz or more in the inner/outer layers of the PCB.

Applications
Increasing copper thickness addresses the needs of high power distribution boards, heat dissipation, planar transformers, and power converters.

Common Issues 
Delamination, inner layer alignment, etching and more.  
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Sample Boards

10 Layer 4oz Copper Buried Vias
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