A semiconductor device mounting structure includes a bus bar of which a
first end part is connected to a high-temperature power-purpose
semiconductor device and a second end is connected to another device that
is required to be kept at a lower temperature than the semiconductor
device. The bus bar includes a ribbonlike part zigzagging between the
first and second ends. The ribbonlike part of the bus bar can improve the
cooling effect by increasing the length of the path through which the
heat travels in the lengthwise direction of the bus bar. Thus, the heat
emitted from the semiconductor device is prevented from being transferred
to a peripheral circuit element through the bus bar used for supplying
electric power to the circuit element from the semiconductor device.