BPS prototyping PCBs are built on high-quality FR4 glass-epoxy material, which provides excellent electrical insulation. The practical working voltage limit depends on the spacing between copper traces on the board. The voltage rating for PCBs determines how much current it can safely carry without overheating. This rating depends on several factors for PCBs including the track width and hole spacing. The recommendations are for ideal use cases and need to be considered alongside other factors before a safe current rating can be achieved.

The maximum Amps should be derated by 50% to account for other components, wires, cables, enclosures, environmental, and other factors that increase temperature and restrict cooling airflow.

• For wide prototyping PCBs with 85mil tracks, (e.g. BR1, StripBoard STx, PR3U, PowerBoard) we recommend 3 Amps maximum to allow for a 10°C/18°F increase track temperature.
• For narrow prototyping PCBs, where the width narrows to to 40mils, (e.g. SB4, SB5, SB400, SB404, SB8300) we recommend 2 Amps maximum to allow for a 10°C/18°F increase.

See the BusBoard application note "BPS-AN0004 PCB Current Capacity.pdf" for more information on how to determine the current capacity rating for your prototype project.

If your project requires more current, cover the entire track with a solder bead to increase its thickness or use two or more tracks in parallel to allow for additional current. Adding tracks to the PCB does not increase current capacity at the same rate, as more heat is generated and airflow is possibly restricted.