Specifying heavy copper—boards with 4 oz/ft² or thicker layers—is rarely done for light-duty applications. It is a decision driven by a specific thermal management challenge: moving massive current through a limited space without compromising the board's integrity. Whether building EV motor controllers or renewable energy inverters, the physics remains the same.
Here is the catch: Standard online PCB calculators often fail to capture the reality of heavy copper.
Most designers instinctively grab a free calculator or a generic IPC chart, plug in the current, and size the trace. While effective for standard 1 oz logic boards, these tools rely on linear assumptions that break down at 4 oz, 10 oz, or heavier weights. Designing for high-power applications requires understanding how these boar ...
