Abstract: The present invention concerns a circuit board (100) having at least one fluid passage (110) arranged in the interior of a circuit board (100), having a fluid passage opening (120) which is arranged on a surface of the circuit board (100) and which leads to the fluid passage (110, and a multi-part pressure-relief valve arrangement (200) for reducing an excess pressure in the fluid passage (110), which includes a first magnet (210), a second magnet (220) and a sealing closure (230), wherein the first magnet (210) and the second magnet (220) are so arranged that they press the sealing closure (230) on to the fluid passage opening (2120) by a magnetic force (250) afforded by the first magnet (210) and by the second magnet (220).