What Are the Operation Methods for PCB to Carry High Current

Operation Methods for PCB to Carry High Current

1. Increase the trace width: the conventional general rule is 1A current corresponding to 1mm (40mil) trace width.
2. Increase the copper pour thickness, such as 1oz, 2oz and other copper thickness specifications.
3. Open a window on the conductor, and add tin, silver, copper and other conductive materials on the exposed copper.

Precautions for PCB Carrying High Current

1. Severe heating problems, especially the local heating phenomenon is more difficult to handle, because the current does not flow through the conductor evenly. In addition, the resistivity of copper and tin is completely different, so the current often still flows through the copper foil, which will cause serious heating of the substrate. It should be noted that the Tg (Glass Transition Temperature) of commonly used FR-4 is generally 140~170℃. If the temperature exceeds this range, although it may not burn, it will directly lead to softening of the substrate and a serious decline in electrical performance.
2. The reliability of the substrate will be greatly reduced. For the method of opening a window on the conductor and adding tin, the solder will melt in the event of a fault, resulting in an open circuit.

Recommended Operations for PCB Carrying High Current

1. Use copper bars as high-current conductors, or directly lead out the circuit with copper plates in the high-current part.
2. Use multilayer boards for high-current transmission, but thermal simulation is required. Because the current does not flow evenly, it may lead to local overheating. The specific analysis shall be carried out according to the copper pour thickness and width of the substrate.
3. Adopt aluminum substrate. In comparison, aluminum substrate has much better heat dissipation and stronger bearing capacity, but the temperature rise still needs to be fully considered under the high current of 150A.

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