Patent ID: 7091587

Claim:
A semiconductor device, comprising: a first semiconductor chip including a bipolar transistor which constitutes a power supply control circuit that converts a first voltage to a second voltage; a second semiconductor chip including an amplifier circuit using the second voltage as a power supply; and a wiring board equipped with the first and second semiconductor chips, wherein the wiring board includes a first surface over which the first and second semiconductor chips are mounted, and a second surface provided at the side opposite to the first surface, wherein a first electrode for an emitter electrode of the bipolar transistor and a second electrode for a collector electrode of the bipolar transistor are provided over the first surface, wherein a third electrode for the first voltage and a fourth electrode for the second voltage are provided over the second surface, and wherein connecting portions extending in the direction intersecting the first and second surfaces of the wiring board are provided in a wiring path in the wiring board, which electrically connects the first electrode of the first surface and the third electrode of the second surface to each other, and a plurality of the connecting portions are bonded to the first electrode and the third electrode.